The world's population is aging dramatically and in most countries the cost of care is rising rapidly. We need a system which helps to minimize the onset of chronic conditions which are costly to treat and diminish quality of life, rather than one primarily directed towards the care of the sick. Innovative use of new technologies may be the only way to provide care affordably in future and to scale that care to far greater numbers as our societies adapt to change. Ambient Assisted Living (AAL) can provide a solution. More integration between the health system and life at home and work will benefit everybody, providing better, more holistic lifelong care at lower cost. This book presents and summarizes the achievements of an accomplished group of researchers around the globe and from diverse technical backgrounds. They use a wide range of approaches to optimize the use of healthcare technology and integrate such technology into human lives in a way that will benefit all. The book is divided into seven main sections: AAL in the health space; Devices and infrastructure to facilitate AAL; AAL in gerontology; Smart homes as a vehicle for AAL; Applications of AAL in rehabilitation; AAL initiatives; and finally, Novel developments and visions for the area. Developing technologies which cater for the broad range of individuals in our complex societies is a major challenge which poses many problems. The research described here pushes the boundaries, and will inspire other researchers to continue their exploration of technologies to improve lives.

Der Begriff "Ambient Assisted Living" (AAL) steht für einen grundlegenden Paradigmenwechsel in der Interaktion zwischen Mensch und Lebensumgebung. AAL-Technologien bilden Assistenzsysteme, die in das direkte Lebensumfeld von Menschen integriert sind. Durch die Anpassung der Systeme an die speziellen Anforderungen ihrer Nutzer erhöhen sie im jeweiligen Nutzungskontext in jedem Lebensalter deren Lebensqualität. Die Industriezweige stehen vor der Herausforderung für AAL-Systeme Märkte zu entwickeln und zur Wirtschaftlichkeit zu führen. Diese Publikation greift diese Thematik auf. Sie behandelt unterschiedliche Geschäftsmodellansätze in sich entwickelnden AAL-Märkten. Im Vordergrund steht zunächst die modellhafte Beschreibung des Geschäftes als eine vereinfachte und 5 aggregierte Darstellung von betrieblichen Produktions- und Leistungssystemen einer Unternehmung. Verwendet wird ein Ansatz, der es erlaubt die besonderen Rahmenbedingungen zu berücksichtigen, die in bestimmten Industriezweigen die Schlüsselfunktionen unternehmerischen Handelns darstellen und den angestrebten wirtschaftlichen Erfolg einer Unternehmung bedingen. Das Modell macht die komplexen Zusammenhänge dem notwendigen Diskurs zugänglich.

In der Computergrafik werden ständig neue Methoden zur effizienten Echtzeitdarstellung komplexer geometrischer Modelle untersucht. Etablierte Verfahren setzen dabei auf die Tessellierung von Dreiecksnetzen in fester Auflösung. Auf Grund der steigenden Komplexität von Modellen führt dies unweigerlich zu komplexen Herausforderungen für die Darstellung. In dieser Arbeit wird ein alternatives Konzept für die Echtzeitdarstellung vorgestellt. Die Grundidee ist die "spät-möglichste" Tessellierung, umgesetzt als Kombination verschiedener Techniken: Die Ansätze der Generativen Modellierung ermöglichen die Integration von blickpunktabhängigen Level of Detail Verfahren zur adaptiven Steuerung der Detailstufe in Echtzeit, direkt auf dem Grafikprozessor durch Nutzung moderner Shader-Technologien. Am konkreten Anwendungsbeispiel der "Rohrdarstellung in Virtual Reality Systemen" wird ein Konzept zum neuen Ansatz entwickelt und dessen Leistungsfähigkeit anhand einer prototypischen Implementierung diskutiert.

Die Untersuchung der Größe und Form von Lymphknoten spielt in der Diagnostik und Verlaufskontrolle von Krebspatienten eine wichtige Rolle. Für diese Untersuchung müssen die Lymphknoten in Computertomographie (CT) Datensätzen segmentiert werden. Die manuelle Segmentierung ist zeitaufwändig und fehleranfällig. Für eine präzise Segmentierung von Lymphknoten sind automatische Segmentierungsverfahren erwünscht. In der Literatur werden einige vielversprechende Segmentierungsalgorithmen beschrieben. Alle diese Algorithmen haben ihre Vor- und Nachteile. Eine Gegenüberstellung der Algorithmen wird vermisst. In dieser Arbeit werden vier neue automatische Segmentierungsalgorithmen entwickelt. Die Parameter der Verfahren werden optimiert. Anhand Goldstandards von Experten werden im Anschluss diese vier Methoden und Regionen-, modell- und strahlenbasierte Segmentierungsalgorithmen aus der Literatur in Bezug auf die Genauigkeit, Laufzeit und Robustheit evaluiert und gegenübergestellt. Für die Evaluierung steht ein CT-Datensatz zur Verfügung, für den manuelle Segmentierungen von Experten vorliegen. Der Datensatz besteht aus 49 Lymphknoten der Kopf- und Halsregion von Patienten mit Mundhöhlenkarzinomen. Bei der Gegenüberstellung der Algorithmen wurde festgestellt, dass der strahlenbasierte Ansatz, bei dem die Segmentierung unter Berücksichtigung lokaler Gradienteneigenschaften und Intensitätseigenschaften von Lymphknoten mit anschließender globaler Optimierung erfolgt, am besten für die Segmentierung von Lymphknoten geeignet ist. Die Laufzeit der Segmentierung ist mit 8 Sekunden pro Lymphknoten 3-5 fache der anderen Segmentierungsverfahren. Die Segmentierung ist aber sehr präzise. Der durchschnittliche DSC beträgt 0.80. Bei der Initialisierung mit unterschiedlichen Saatpunkten ist die Methode sehr robust. Bei der Segmentierung von vergrößerten Lymphknoten beträgt der durchschnittliche DSC 0.86, bei der Segmentierung von nekrotischen Lymphknoten 0.81. Anhand von automatischen Segmentierungsalgorithmen können Lymphknoten erfolgreich segmentiert werden. Die Ergebnisse der Segmentierung können z.B. für die dreidimensionale Visualisierung, Verlaufskontrolle von Krebspatienten oder Operationsplanung weiterverarbeitet werden.

Yoshida, Hiroyuki (Ed.) et al.: Abdominal Imaging : Computational and Clinical Applications. Berlin, Heidelberg, New York: Springer, 2012. (Lecture Notes in Computer Science (LNCS) 7029), pp. 108-115

Registration of liver CT scans from different points in time or different phases of contrast agent saturation is a highly demanded tool for computer aided diagnosis, operation planning and intervention. This work presents a complete registration workflow to precisely overlap scans from 4 different application scenarios including registration of pretreatment and post-treatment data as well as registration of multi-phase CT. Various state of the art techniques in shape modeling and matching, visualization as well as augmented interaction are applied to cover all of the described scenarios in a clinically usable system. Our system has been in use for clinical evaluation under real life conditions and has been tested on more than 30 patients.

JROI-Journal of Radiation Oncology Informatics, Vol.4 (2012), 1, pp. 1-23

Image segmentation and registration have been the two major areas of research in the medical imaging community for decades and still are. In the context of radiation oncology, segmentation and registration methods are widely used for target structure definition such as prostate or head and neck lymph node areas. In the past two years, 45% of all articles published in the most important medical imaging journals and conferences have presented either segmentation or registration methods. In the literature, both categories are treated rather separately even though they have much in common. Registration techniques are used to solve segmentation tasks (e.g. atlas based methods) and vice versa (e.g. segmentation of structures used in a landmark based registration). This article reviews the literature on image segmentation methods by introducing a novel taxonomy based on the amount of shape knowledge being incorporated in the segmentation process. Based on that, we argue that all global shape prior segmentation methods are identical to image registration methods and that such methods thus cannot be characterized as either image segmentation or registration methods. Therefore we propose a new class of methods that are able solve both segmentation and registration tasks. We call it regmentation. Quantified on a survey of the current state of the art medical imaging literature, it turns out that 25% of the methods are pure registration methods, 46% are pure segmentation methods and 29% are regmentation methods. The new view on image segmentation and registration provides a consistent taxonomy in this context and emphasizes the importance of regmentation in current medical image processing research and radiation oncology image-guided applications.

Embedded World 2012: Exhibition & Conference : It's a Smarter World. Haar: WEKA Fachmedien, 2012, 10 p.

The recognition of gestures in free space using sensors that determine the proximity of a body mass based on electric field variance is a challenging research topic. Arrays of such capacitive proximity sensors allow the creation of novel user interaction systems based on recognizing presence and position of body parts and inferring performed gestures in three dimensions from that information. These systems may be incorporated as unobtrusive remote control in home automation scenarios or automotive applications, for example as a smart car-dashboard. Present systems that use time-division multiplexing have limitations in their temporal and spatial resolution. In this paper we present the Honeyfish - a novel capacitive proximity sensing system that uses a combination of frequency division and time division multiplex, improving both temporal and spatial resolution. With this affordable system we are able to detect fast multi-hand gestures in three dimensions above large surface areas.

The recognition of gestures in free space using sensors that determine the proximity of a body mass based on electric field variance is a challenging research topic. Arrays of such capacitive proximity sensors allow the creation of novel user interaction systems based on recognizing presence and position of body parts and inferring performed gestures in three dimensions. These systems may be incorporated as unobtrusive remote control in home automation scenarios or automotive applications, for example as a smart car-dashboard. Present systems that use time-division multiplexing have limitations in their temporal and spatial resolution. In this thesis a novel capacitive proximity sensor system that uses a combination of frequency division and time division multiplex is presented, improving both temporal and spatial resolution. With this affordable system one is able to detect fast multi-hand gestures in three dimensions above large surface areas. Moreover, a method for object recognition using capacitive proximity sensors is extended and refined and a new object tracking method, employing particle filters is presented. A user evaluation emphasizes the feasibility of the presented capacitive sensing system as an explicit interaction modality.

Economic Engineering: Intelligente Methoden, Prozesse und Technologien, (2012), 2, pp. 84-86

ln den vergangenen Jahren haben die Schäden durch Wirtschaftsspionage und Produktpiraterie kontinuierlich zugenommen, und es ist nicht zu erwarten, dass sich dieser Trend in naher Zukunft abschwächen wird. Enterprise Rights Management (ERM) bietet eine sehr umfassende Möglichkeit, Daten vor unerlaubtem Zugriff zu schützen. Im Gegensatz zu herkömmlichen Lösungen zum Dokumentenschutz wird bei ERM der Schutz direkt an den zu schützenden Inhalten angebracht und sichergestellt, dass dieser nicht entfernt werden kann. Mit anderen Worten: egal wohin die Daten wandern, der Schutz reist mit.

Institut für Rohrleitungsbau Oldenburg (iro): 26. Oldenburger Rohrleitungsforum 2012 : Rohrleitungen - in neuen Energieversorgungskonzepten. Essen: Vulkan-Verlag, 2012. (Schriftenreihe aus dem Institut für Rohrleitungsbau Oldenburg (iro) 37), pp. 783-788

This paper describes the goals of the DeepCity3D project which aims to provide an integrated visualization of 3D city models, geology and underground constructions such as tunnels and pipelines. Such a combined visualization is supposed to help urban planners, construction companies and emergency management. The project also introduces new concepts for visualizing uncertain underground data in 3D.

Information Visualization, Vol.11 (2012), 1, pp. 60-70

The reconstruction of a continuous function from discrete data is a basic task in many applications such as the visualization of 3D volumetric data sets. We use a local approximation method for quadratic C1 splines on uniform tetrahedral partitions to achieve a globally smooth function. The spline is based on a truncated octahedral partition of the volumetric domain, where each truncated octahedron is further split into a fixed number of disjunct tetrahedra. The Bernstein-Bézier coefficients of the piecewise polynomials are directly determined by appropriate combinations of the data values in a local neighborhood. As previously shown, the splines provide an approximation order two for smooth functions as well as their derivatives. We present the first visualizations using these splines and show that they are well-suited for GPU-based, interactive high-quality visualization of isosurfaces from discrete data.

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 5. AAL-Kongress 2012. Berlin, Heidelberg, New York: Springer, 2012. (Advanced Technologies and Societal Change), pp. 289-304

The interaction between a technical system and the user is a main issue in information technology. In the field of Ambient Assisted Living (AAL) this is even more important due to the physical or mental restrictions of the users. Explicitly controlling a technically heterogeneous environment like a living area can be very complicated (e.g. using remote controls with complex interfaces) or even physically annoying (e.g. searches remote controls or need to walk to a light switch). Thus, it is desirable to control the environment by simple pointing gestures or by using a centralized device. The base for this is a valid 3D representation of the environment including all required elements. In this paper, we present a new approach of an ontological representation of the real world and the dynamic service in-vocation according to this ontological 3D information. This concept is further described and validated by two application examples using a 3D GUI at a Tablet-PC and pointing gestures to control the AAL Space.

Computersimulationen zur Unterstützung von Ärzten bei der Diagnose und Therapie (z.B. zur Navigation bei chirurgischen Eingriffen) sind im Vormarsch. Solche medizinischen Softwareapplikationen bieten ein hohes Maß an Präzision und unterstützen den Chirurgen bei der Operation. Bei der operativen Entfernung eines Tumors aus der Leber beispielsweise werden auch Teile der Leber mit entfernt. Diese operative Entfernung von Gewebe aus einem Organ wird auch als Resektion bezeichnet. Eine computergestützte Planung von Resektionsstellen in der präoperativen Phase ermöglicht eine exakte Bestimmung der Gefäße, welche den Tumor versorgen und welche Gefäße zur weiteren Durchblutung anderer Segmente der Leber benötigt werden. Diese Möglichkeit der Operationsplanung führt zu einer Minimierung von Komplikationen während der Operation und somit nicht zuletzt zu einer höheren Heilungsquote und schnelleren Genesung des Patienten. Hierzu werden in der präoperativen Phase die Gefäße aus einem durch Computertomographie (CT) gewonnenen Volumenbild der Leber segmentiert. Der verwendete Segmentierungsalgorithmus muss dabei trotz unterschiedlich starkem Kontrast und Rauschen der CT-Bilddaten möglichst präzise Ergebnisse erzielen. Es ist daher immens wichtig, bei der Erstellung einer solchen medizinischen Applikation ein geeignetes Segmentierungsverfahren zu wählen oder aber auch selbst zu entwickeln. Die Ergebnisse, die dieser Segmentierungsalgorithmus liefert, sollten frühzeitig evaluiert werden. Zwar wird in zahlreichen Publikationen für neu entwickelte Segmentierungsalgorithmen mit guten Evaluationsergebnissen geworben, jedoch wurden diese getrennt voneinander und mit unterschiedlicher Herangehensweise in der Implementierung und Wahl der Metriken evaluiert. Ein quantitativer Vergleich zwischen diesen Segmentierungsalgorithmen ist deshalb nicht möglich. Diese Arbeit zeigt nun den Weg von der Konzipierung bis hin zur Umsetzung einer Testumgebung, die eine standardisierte und somit objektive und zuverlässige Evaluierung von Segmentierungsalgorithmen ermöglicht. Diese Algorithmen werden dabei mit Hilfe derselben Evaluationsmetriken untersucht und die Ergebnisse in einen quantitativen Vergleich gesetzt. Als "Ground-Truth-Segmentierung" dienen Gefäßbäume, die auf Basis biologischer Wachstumsprozesse simuliert werden. Demonstriert wird die Funktionalität der Testumgebung in Form einer beispielhaften Evaluierung von zwei Segmentierungsalgorithmen.

Yoshida, Hiroyuki (Ed.) et al.: Abdominal Imaging : Computational and Clinical Applications. Berlin, Heidelberg, New York: Springer, 2012. (Lecture Notes in Computer Science (LNCS) 7029), pp. 133-140

Computer aided navigation augments intraoperatively gathered U/S with planning information that the doctor carries out before the intervention on a CT volume. A crucial step for the navigation is the registration between CT and U/S. Our approach consists on a landmark based registration. The correspondences between both modalities are found automatically using a graph to graph matching algorithm. Therefore, liver and vessels are previously segmented. The whole process has being tested on 15 pairs of real clinical data. The results are promising.

Computers & Graphics, Vol.36 (2012), 1, pp. 16-27. First published 29 October 2011 as Article in Press

We present a novel 3D geometry acquisition technique at high resolution based on structured light reconstruction with a low-cost projector-camera system. Using a 1D mechanical lens-shifter extension in the projector light path, the projected pattern is shifted in subpixel scale steps with a granularity of up to 2048 steps per projected pixel, which opens up novel possibilities in depth accuracy and smoothness for the acquired geometry. Combining the mechanical lens-shifter extension with a multiple phase shifting technique yields a measuring range of 120×80 mm while at the same time providing a high depth resolution of better than 100µm. Reaching beyond depth resolutions achieved by conventional structured light scanning approaches with projector-camera systems, depth layering effects inherent to conventional techniques are fully avoided. Relying on low-cost consumer products only, we reach an area resolution of down to 55µm (limited by the camera). We see two main benefits. First, our acquisition setup can reconstruct finest details of small cultural heritage objects such as antique coins and thus digitally preserve them in appropriate precision. Second, our accurate height fields are a viable input to physically based rendering in combination with measured material BRDFs to reproduce compelling spatially varying, material-specific effects.

This work presents a way to estimate the matching probabilities for histogrammed intensity patches [41] by approximating the robustness and distinctiveness of a feature with beta distributions. We propose a simplified analytical approach to calculate the distinctiveness and show that it produces at least as good results as a specifically trained neural network. The matching probability correlates stronger with the inlier ratio than the dissimilarity score does. We then evaluate a basic tracking by detection pipeline where no longer the closest but the most probable match is chosen. Our tests show, that this improves the average performance of the system in terms of tracking rate.

Multimedia Systems Conference 2012 ( MMSys '12). New York: ACM, 2012, pp. 23-28

3D Object Retrieval is an important field of research with many application possibilities. One of the main goals in this research is the development of discriminative methods for similarity search. The descriptor-based approach to date has seen a lot of research attention, with many different extraction algorithms proposed. In previous work, we have introduced a simple but effective scheme for 3D model retrieval based on a spatially fixed combination of 3D object fragment descriptors. In this work, we propose a novel flexible combination scheme based on finding the best matching fragment descriptors to use in the combination. By an exhaustive experimental evaluation on established benchmark data we show the capability of the new combination scheme to provide improved retrieval effectiveness. The method is proposed as a versatile and inexpensive method to enhance the effectiveness of a given global 3D descriptor approach.

Bruckstein, Alfred M. (Ed.) et al.: Scale Space and Variational Methods in Computer Vision. Proceedings : SSVM 2011. Berlin, Heidelberg, New York: Springer, 2012. (Lecture Notes in Computer Science (LNCS) 6667), pp. 62-73

We present an efficient implementation of volumetric nonlinear anisotropic image diffusion on modern programmable graphics processing units (GPUs). We avoid the computational bottleneck of a time consuming eigenvalue decomposition in R3. Instead, we use a projection of the Hessian matrix along the surface normal onto the tangent plane of the local isodensity surface and solve for the remaining two tangent space eigenvectors. We derive closed formulas to achieve this resulting in efficient GPU code. We show that our most complex volumetric nonlinear anisotropic diffusion gains a speed up of more than 600 compared to a CPU solution.

Augusto, Juan Carlos (Ed.) et al.: Handbook of Ambient Assisted Living : Technology for Healthcare, Rehabilitation and Well-being. Amsterdam; Berlin: IOS Press, 2012. (Ambient Intelligence and Smart Environments 11), pp. 612-625

Ambient Assisted Living (AAL) is lacking a reference model that can serve as a basis for understanding the main issues to be addressed without any solution bias. Such a reference model will facilitate consensus-building processes and consolidation efforts towards converging conclusions on AAL infrastructures. The universAAL project, that aims at producing an open platform along with a standardized approach for making it technically feasible and economically viable to develop AAL solutions, has defined a process consisting of four iterations for filling this gap. Here, the results of the first iteration on a reference model for AAL are presented.

NAFEMS Online Magazin, Vol.21 (2012), 1, pp. 70-79

Ein wichtiger Teil des Produktentwicklungszyklus ist die Optimierung der strömungs- oder strukturmechanischen Eigenschaften einer Komponente, die normalerweise in einem iterativen und sehr aufwändigen Prozess stattfindet. Neben der Modifikation, Vereinfachung und des Vernetzens der Bauteilgeometrie, kann die Simulation mitunter Stunden bis Tage dauern. In frühen konzeptionellen Designphasen müssen verschiedene Materialparameter sowie unterschiedliche Geometrien ausprobiert und verglichen werden, um zu einem für das spätere Produkt optimalen Design zu gelangen. Dieser zeitaufwändige Prozess begrenzt deutlich die Anzahl der Möglichkeiten, die analysiert werden können. In dieser Arbeit wird das Framework "Rapid CFD" vorgestellt, das es ermöglicht, schnelle Strömungssimulationen für die frühe konzeptionelle Designphase einzusetzen. Um eine solche Geschwindigkeit zu erreichen, wird die Berechnung und Visualisierung von zweidimensionalen Strömungen in Echtzeit kombiniert. Das ermöglicht die interaktive Modifikation von Parametern und Randbedingungen und damit eine schnelle Analyse und Bewertung von unterschiedlichen Geometrien und eine frühzeitige Optimierung eines Bauteils. Das Framework führt alle Berechnungen auf der Graphikkarte (graphics processing unit - GPU) aus und vermeidet damit das aufwändige Kopieren zwischen CPU- und GPU-Hauptspeicher. Die Berechnungen werden auf einem Standard-Desktop PC ausgeführt, sodass die Simulationsergebnisse im Graphikkartenspeicher bleiben und direkt zur Visualisierung verwendet werden können. Für die Modellierung der Geometrie werden B-Splines verwendet, damit Benutzer lokal die Form durch einzelne Kontrollpunkte modifizieren können. Die Diskretisierung wird ebenfalls auf der GPU ausgeführt. Die Berechnung eines einzelnen Zeitschritts auch für Millionen von Unbekannten wird in Bruchteilen von Sekunden durchgeführt. Die intuitive geometrische Manipulation in Kombination mit der unmittelbaren Visualisierung der Simulationsgrößen wie Druck und Geschwindigkeit ermöglichen die direkte Analyse des Einflusses von Geometrie- und Parameteränderungen. Obwohl diese neuartige Simulationstechnik noch nicht die hohe Präzision konventioneller Simulationen erreicht, ermöglicht diese Technik die Beobachtung von Trends und Tendenzen.

Augusto, Juan Carlos (Ed.) et al.: Handbook of Ambient Assisted Living : Technology for Healthcare, Rehabilitation and Well-being. Amsterdam; Berlin: IOS Press, 2012. (Ambient Intelligence and Smart Environments 11), pp. 495-497

Rehabilitation techniques in Ambient Assisted Living, which concentrates on supporting persons with special needs, is viewed as one of the most promising areas of AAL (Ambient Assisted Living). Thus these technologies for rehabilitation constitute a major research area within AAL research. A large number of new technologies have been developed in R&D projects for rehabilitation in recent years. Lots of project results in form of applications and prototypes have been developed. This section contains important work on technologies to support people with chronic obstructive pulmonary disease, on robotics for remote motor rehabilitation, smart home technologies to help people with cognitive impairments, Tele-Rehabilitation approaches, Cardiac Rehabilitation solutions and Computer Vision Access Technologies, but all focused on Ambient Assisted Rehabilitation. Authors from Northern America, Australia and Europe highlighted their work in Ambient Assisted Rehabilitation in the following six chapters.

In this book, leading authors in the field discuss development of Ambient Assisted Living. The contributions have been chosen and invited at the 5th AAL congress, Berlin. It presents new technological developments which support the autonomy and independence of individuals with special needs. As the technological innovation raises also social issues, the book addresses micro and macro economical aspects of assistive systems and puts an additional emphasis on the ethical and legal discussion. The presentation is supported by real world examples and applications.

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 5. AAL-Kongress 2012. Berlin, Heidelberg, New York: Springer, 2012. (Advanced Technologies and Societal Change), pp. 349-358

Since the changing demographics the European Commission as well as near all national funding organisations see the necessity to support assisted technologies through huge funding instruments. Despite its tremendous market potential, AAL (Ambient Assisted Living) is still on the cusp of a mainstream break-through. A lack of viable business models is considered almost unanimously to be the greatest market obstacle to a broad implementation of innovative AAL systems. This paper describes the sustainable approach by universAAL and AALOA to overcome this market entrance barrier by mobilizing the AAL community and influencing the funding programs to achieve the market breakthrough in AAL.

Biometrics enables convenient authentication based on a person's physical or behavioral characteristics. In comparison with knowledge- or token-based methods, it links an identity directly to its owner. Furthermore, it can not be forgotten or handed over easily. As biometric techniques have become more and more efficient and accurate, they are widely used in numerous areas. Among the most common application areas are physical and logical access controls, border control, authentication in banking applications and biometric identification in forensics. In this growing field of biometric applications, concerns about privacy and security cannot be neglected. The advantages of biometrics can revert to the opposite easily. The potential misuse of biometric information is not limited to the endangerment of user privacy, since biometric data potentially contain sensitive information like gender, race, state of health, etc. Different applications can be linked through unique biometric data. Additionally, identity theft is a severe threat to identity management, if revocation and reissuing of biometric references are practically impossible. Therefore, template protection techniques are developed to overcome these drawbacks and limitations of biometrics. Their advantage is the creation of multiple secure references from biometric data. These secure references are supposed to be unlinkable and non-invertible in order to achieve the desired level of security and to fulfill privacy requirements. The existing algorithms can be categorized into transformation-based approaches and biometric cryptosystems. The transformation-based approaches deploy different transformation or randomization functions, while the biometric cryptosystems construct secrets from biometric data. The integration in biometric systems is commonly accepted in research and their feasibility according to the recognition performance is proved. Despite of the success of biometric template protection techniques, their security and privacy properties are investigated only limitedly. This predominant deficiency is addressed in this thesis and a systematic evaluation framework for biometric template protection techniques is proposed and demonstrated: Firstly, three main protection goals are identified based on the review of the requirements on template protection techniques. The identified goals can be summarized as security, privacy protection ability and unlinkability. Furthermore, the definitions of privacy and security are given, which allow to quantify the computational complexity estimating a pre-image of a secure template and to measure the hardness of retrieving biometric data respectively. Secondly, three threat models are identified as important prerequisites for the assessment. Threat models define the information about biometric data, system parameters and functions that can be accessed during the evaluation or an attack. The first threat model, so called naive model, assumes that an adversary has very limited information about a system. In the second threat model, the advanced model, we apply Kerckhoffs' principle and assume that essential details of algorithms as well as properties of biometric data are known. The last threat model assumes that an adversary owns large amount of biometric data and this allows him to exploit inaccuracy of biometric systems. It is called the collision threat model. Finally, a systematic framework for privacy and security assessment is proposed. Before an evaluation process, protection goals and threat models need to be clarified. Based on these, the metrics measuring different protection goals as well as an evaluation process determining the metrics will be developed. Both theoretical evaluation with metrics such as entropy, mutual information and practical evaluation based on individual attacks can be used. The framework for privacy and security assessment is applied on the biometric cryptosystems: fuzzy commitment for 3D face and iris recognition is assessed. I develop my own 3D face recognition algorithm based on the depth distribution of facial sub-surfaces and integrate it in the fuzzy commitment scheme. The iris recognition is based on an open source algorithm using Gabor filter. It is implemented in the fuzzy commitment scheme with the two layer coding method as proposed by Hao et al. Both features, the 3D face features and the iris features, represent local characteristics of the modalities. Thus, strong dependency within these features is observed. The second order dependency tree is applied to describe the distribution of 3D face features. The Markov model is applied to characterize the statistical properties of iris features. Thus, security and privacy of these algorithms can be measured with theoretical metrics. Due to strong feature dependency, the achieved security is much smaller than the secret size, which is the assumed security in a perfect secure case with uniformly identically distributed features. Moreover, the unlinkability is analyzed. The analysis shows that these protected systems are less vulnerable to leakage amplification. However, the secure templates contain much personal identifiable information. We demonstrate the attacks, which can identify a subject by linking auxiliary data stored in his secure templates. Cross matching is assessed with the performance of these attacks. Additionally, the characteristic of iris features is exploited to perform an attack retrieving features from secure templates. The efficiency of the practical attack confirms the result of the theoretical assessment of privacy with conditional entropy. The coding process plays a very important role for the security and privacy properties in the fuzzy commitment scheme. Designing a coding method should not only focus on the improvement of code rate. As shown in this thesis, security and privacy properties can be enhanced significantly by changing the dependency pattern in iris features and 3D face features. Therefore, the coding process should be adapted to properties of the underlying biometric features to increase the security and privacy performance. The security and privacy assessment within this thesis is completed by a comparison of two fuzzy commitment algorithms with the fuzzy vault algorithm for fingerprint recognition. Here, different threat models as well as the corresponding protection goals are considered. The fuzzy vault system has the best performance regarding security and irreversibility of biometric features. However, all of these systems are vulnerable to cross matching. The comparison results show that the proposed evaluation framework provides the fundamental basis for benchmarking different template protection algorithms. The proposed framework is also validated with the existing security analysis on transformation-based approaches. Unlike the analysis on biometric cryptosystems, the security is dependent on the hardness of transformation functions or randomization processes. Therefore, the presented analysis is based on efficiency of different kinds of attacks, which measure different protection goals in the appropriate threat models. The security of these approaches depends on the transformation parameters. The knowledge of these parameters allows generating a pre-image, while it is still hard to estimate the original biometric features practically. However, privacy leakage amplifications are still possible. This thesis defines a systematic evaluation framework, which adheres to essential criteria and requirements of biometric template protection techniques. Its applicability is demonstrated with the analysis of template protection algorithms for different biometric modalities. The assessment presented in this thesis is fundamental for a thorough analysis. Furthermore, it provides provable evidence on security and privacy performance. Therefore, it is the fundamental tool for technical innovation and improvement and helps system designers in selecting a suitable template protection algorithm for their applications and needs. It creates a basis for certification and benchmarking of biometric template protection.

Motivation dieser Arbeit ist die Entwicklung eines Programms zur Unterstützung von Monteuren bei der Wartung und Reparatur eines Fahrzeugs. Durch automatische Einblendungen, welche in der erfassten Szene angezeigt werden, wird vorgegeben welcher Schritt als nächstes ausgeführt werden soll. Unter anderem sollen die zu bearbeitenden Stellen durch das Einblenden von CAD-Objekten hervorgehoben werden. Um die Objekte an der richtigen Stelle einzublenden, muss die aktuelle Position und Orientierung der Kamera bekannt sein. Zur Berechnung der Kamerapose ist ein zuverlässiges Feature-Matching nötig, bei dem die benötigte 3D-Position der Features bestimmt wird. Da das System in Echtzeit arbeiten soll, kommt es hierbei vor allem auf eine schnelle aber dennoch genaue Ausführung an. Eine vielversprechende Methode zur Verkürzung der benötigten Rechenzeit besteht in der Kombination von Matching mit Visual Words. Das Ziel dieser Arbeit ist daher die Entwicklung eines Systems zum Feature-Matching mit Hilfe der Visual Words und wird ergänzt durch die anschließende Berechnung der Kamerapose. Als Feature-Detektor wird der SURF-Algorithmus verwendet. Die Visual Words werden umgesetzt, indem in der Lernphase die Features aller Bilder in Cluster eingeteilt werden. In Histogrammen wird festgehalten, wie sich die Features eines Bildes auf die Cluster verteilen. Beim späteren Tracking wird anhand von aktuellen Features ein Histogramm erstellt und mit den gespeicherten Histogrammen verglichen. Für das Matching werden nur diejenigen Bilder ausgewählt, die ein ähnliches Histogramm besitzen. Dies führt zu einer besseren und vor allem schnelleren Auswahl der Features, da Features, welche in diesem Bildausschnitt nicht vorkommen können, von der Suche ausgeschlossen werden. Dieses Vorgehen ermöglicht ein schnelles und gleichzeitig genaues Matching, wodurch auch die Berechnung der Kamerapose beschleunigt wird. Während die berechnete Kamerapose für ein durchgängiges Tracking möglicherweise nicht stabil genug ist, bietet sich das Verfahren vor allem für eine schnelle Initialisierungsphase an.

Journal of Ambient Intelligence and Humanized Computing, (2011), Online first. Corrected proof 10 November 2011. DOI: 10.1007/s12652-011-0095-6, 18 p.

User activity monitoring is a major problem in ambient assisted living, since it requires to infer new knowledge from collected and fused sensor data while dealing with highly dynamic environments, where devices continuously change their availability and (or) physical location. In the context of the European project PERSONA, we have developed an activity monitoring sub-system characterized by high modularity, little invasiveness of the environment and good responsiveness. In this paper we first illustrate the functional architecture of the proposed solution from a general point of view, discussing the motivations of the design. Then we describe in details the software components- sensor abstraction and integration layer, human posture classification, activity monitor-and the resulting activity monitoring application, presenting also a performance evaluation.

Dreidimensionale digitale Stadtmodelle werden immer mehr in den verschiedensten Anwendungsgebieten eingesetzt, hierzu gehören beispielsweise Stadtplanung, Umwelt- und Katastrophenmanagement sowie Funknetzplanung. Es kann beobachtet werden, dass die vorhandenen Daten den Anforderungen der verschiedenen Anwendungen oft nicht genügen. Dies liegt zum einen an den nicht geeigneten Erfassungsmethoden oder daran, dass die Daten nicht korrekt für das jeweilige Anwendungsgebiet aufbereitet worden sind. Im Rahmen dieser Arbeit wird die Integration eines Qualitätssicherungssystems in ein 3D-Geoinformationsystem behandelt. Aufgabe dieser Arbeit war es, ein Konzept zu erstellen, wie ein vorhandenes Qualitätssicherungssystem in ein 3D-GIS eingebunden werden kann. Dies beinhaltet auch die Analyse der Schnittstelle zur Integration der Daten. Die Informationen aus einem Stadtmodell, welches in einem bestimmten Datenmodell vorliegt, sollen an ein vorhandenes Qualitätssicherungssystem übergebenen werden, welches wiederum ein anderes Datenmodell verwendet. Aufbauend auf diesem Konzept ist ein Plugin für den CityServer3D entstanden, welches das selektierte Stadtmodell in das Datenformat zur Qualitätssicherung umwandelt, die Qualitätssicherung durchführt und dem Benutzer ein Übersicht der gefunden Korrekturvorschläge zur Verfügung stellt. Beachtet werden musste hierbei, dass bei der Umwandlung der Datenmodelle vor und nach der Korrektur keine Informationen, weder geometrische noch semantische, verloren gehen. Die Ergebnisse dieser Arbeit wurden in Anwendungsnahen Beispielen evaluiert. Insgesamt ist diese Arbeit als Basis zur Verwirklichung des Integrationsprozess anzusehen und dient als Prototyp für das Verbundvorhaben "CityDokto". Als Technologien wurden Java, OSGi, Eclipse RCP sowie Spring verwendet.

"Ambient Assisted Living" (AAL) bezeichnet die Vision von Alltagsumgebungen, die den Menschen bei seinen täglichen Aktivitäten proaktiv unterstützen. Ambient Assisted Living zielt insbesondere darauf ab, das selbständige und selbstbestimmte Leben Älterer in der eigenen Häuslichkeit zu ermöglichen. Damit ist AAL eine wichtige Antwort auf die Herausforderungen des demographischen Wandels. Grundlage von AAL ist Sensor- und Aktortechnik, die in die Alltagsumgebung eingebettet ist, Analyse- und Steuerungssoftware, sowie Vernetzungstechnik (Hardware- und Software). AAL steht dabei nicht alleine für den Einsatz von moderner Technik. Der Mehrwert von AAL wird insbesondere aus der Verknüpfung von technischen Errungenschaften mit vorhandenen und innovativen Dienstleistungen generiert. Da innovative Dienstleistungen im AAL-Bereich jedoch bislang die Ausnahme bilden, wird in diesem Papier die technische Bestandsaufnahme im Vordergrund stehen. Ziel des ersten Teils dieses Werkes ist es, einen Überblick über AAL-Produkte und Lösungsansätze zu bieten und Potentiale für neue Entwicklungen zu identifizieren. Nachdem im Kapitel 1 AAL-Systeme in allgemeiner Hinsicht beleuchtet werden, wird in Kapitel 2 auf einige existierende Produkte und Services eingegangen. Anschließend werden die einzelnen Komponenten eines AAL-Systems aus technischer Sicht im Detail vorgestellt. Aktuelle Forschungsprojekte werden in Kapitel 4 vorgestellt. Als Abschluss wird in Kapitel 5 der Handlungsbedarf identifiziert und es werden einige Handlungsempfehlungen zusammengetragen. Der zweite Teil dieses Werkes gibt einen detaillierten Überblick über einzelne Produkte und Services, sowie über Einzelkomponenten eines AAL-Systems.

ACM SIGGRAPH: Proceedings Web3D 2011 : 16th International Conference on 3D Web Technology. New York: ACM Press, 2011, pp. 81-88

The previous publications on X3DOM focused on the general integration model [Behr et al. 2009] and implementation strategies [Behr et al. 2010]. The aspects of dynamic and interactive worlds were an essential part, but not specifically addressed as such. The recent major additions to the system are CSS Animations and CSS 3D-Transforms as well as various forms of events for user interaction and system monitoring, which complement the existing design to support a large number of interactive and dynamic use cases. This overall design, including scene update mechanisms, animations, and a large number of DOM-based events are thus presented in this paper as part of a single overall system design.

The Visual Computer, Vol.27 (2011), 6-8, pp. 485-494

We present a genetic algorithm for approximating densely sampled curves with uniform cubic B-Splines suitable for Combined B-reps. A feature of this representation is altering the continuity property of the B-Spline at any knot, allowing combining freeform curves and polygonal parts within one representation. Naturally there is a trade-off between different approximation properties like accuracy and the number of control points needed. Our algorithm creates very accurate B-Splines with few control points, as shown in Fig. 1. Since the approximation problem is highly nonlinear, we approach it with genetic methods, leading to better results compared to classical gradient based methods. Parallelization and adapted evolution strategies are used to create results very fast.

International Journal on Digital Libraries, Vol.11 (2011), 2, pp. 111-123

Digital Library support for textual and certain types of non-textual documents has significantly advanced over the last years. While Digital Library support implies many aspects along the whole library workflow model, interactive and visual retrieval allowing effective query formulation and result presentation are important functions. Recently, new kinds of non-textual documents which merit Digital Library support, but yet cannot be fully accommodated by existing Digital Library technology, have come into focus. Scientific data, as produced for example, by scientific experimentation, simulation or observation, is such a document type. In this article we report on a concept and first implementation of Digital Library functionality for supporting visual retrieval and exploration in a specific important class of scientific primary data, namely, time-oriented research data. The approach is developed in an interdisciplinary effort by experts from the library, natural sciences, and visual analytics communities. In addition to presenting the concept and to discussing relevant challenges, we present results from a first implementation of our approach as applied on a real-world scientific primary data set. We also report from initial user feedback obtained during discussions with domain experts from the earth observation sciences, indicating the usefulness of our approach.

Dogru, Ali H. (Ed.) et al.: Modern Software Engineering Concepts and Practices : Advanced Approaches. Hershey: IGI Global, 2011, pp. 151-195

The service-oriented architecture has become one of the most popular approaches for distributed business applications. A new trend service ecosystem is merging, where service providers can augment their core services by using business service delivery-related available functionalities like distribution and delivery. The semantic service description of services for the business service delivery will become a bottleneck in the service ecosystem. In this chapter, the Visual Semantic Analysis approach is presented to support semi-automatic modeling of semantic service description by combining machine learning and interactive visualization techniques. Furthermore, two application scenarios from the project THESEUSTEXO (funded by German federal ministry of economics and technology) are presented as evaluation of the Visual Semantic Analysis approach.

A new trend Web service ecosystems for Service-Oriented Architectures (SOAs) and Web services is emerging. Services can be offered and traded like products in these ecosystems. The explicit formalization of services' non-functional parameters, e.g. price plans and legal aspects, as Service Descriptions (SD) is one of the main challenges to establish such Web service ecosystems. The manual modeling of Service Descriptions (SDs) is a tedious and cumbersome task. In this thesis, we introduce the innovative approach Visual Semantic Analysis (VSA) to support semi-automatic modeling of service descriptions in Web service ecosystems. This approach combines the semantic analysis and interactive visualization techniques to support the analysis, modeling, and reanalysis of services in an iterative loop. For example, service providers can analyze first the price plans of the already existing services and extract semantic information from them (e.g. cheapest offers and functionalities). Then they can reuse the extracted semantics to model the price plans of their new services. Afterwards, they can reanalyze the new modeled price plans with the already existing services to check their market competitiveness in Web service ecosystems. The experts from different domains, e.g. service engineers, SD modeling experts, and price plan experts, were interviewed in a study to identify the requirements for the VSA approach. These requirements cover aspects related to the analysis of already exiting services and reuse of the analysis results to model new services. Based on the user requirements, we establish a generic process model for the Visual Semantic Analysis. It defines sub processes and transitions between them. Additionally, the technologies used and the data processed in these sub processes are also described. We present also the formal specification of this generic process model that serves as a basis for the conceptual framework of the VSA. A conceptual framework of the VSA elucidates structure and behavior of the Visual Semantic Analysis System. It specifies also system components of the VSA system and interaction between them. Additionally, we present the external interface of the VSA system for the communication with Web service ecosystems. Finally, we present the results of a user study conducted by means of the VSA system that is developed on the base of the VSA conceptual framework. The results of this user study show that the VSA system leads to strongly significant improvement of the time efficiency and offers better support for the analysis, modeling and reanalysis of service descriptions.

Institut für Multimediatechnik (IFM): 6. Multimediakongress Wismar 2011 : Netzwerk - Forschung - Innovation, 7 pp.

Zunehmend verbreitet sich der Einsatz von digitalen Wartungshandbüchern und begleitender Multimedia- Unterstützung bei Montage und Wartungsarbeiten. Interaktive PDF Dokumente, Montagevideos oder Audioanleitungen können auf immer preiswerter werdenden Tablet PCs oder Smartphones zielgerecht angeboten werden. Im realen Arbeitsumfeld können jedoch Probleme mit der Bedienung dieser Geräte auftreten, da Arbeitshandschuhe getragen werden oder die Hände nicht frei oder stark verschmutzt sind. Neue Interaktionsformen können hier helfen, indem sie eine robuste Bedienung der Geräte ohne Einsatz einzelner Finger ermöglicht. Bereits heute sind erste Geräte am Markt, die entsprechende Interaktionen sowie neue Visualisierungsmöglichkeiten eröffnen. Handgelenksdisplays und bald auch Uhrenhandys (wrist phones) mit entsprechenden Minidisplays und integrierten Sensoren ermöglichen schon heute faszinierende Interaktionen. Dieser Beitrag beschreibt neue Konzepte zur Interaktion mit Handgelenkssensoren und -displays und stellt die damit möglich gewordene Hands-free Interaction (HFI) für mobile Assistenzsysteme vor. Die Technologie der HFI trennt die Phasen der normalen Bewegung während der Arbeitsausführung von den Bewegungen innerhalb der Interaktionsphase. Dieses ermöglicht eine nahtlose Bedienung von Geräten im Arbeitsablauf und es ergeben sich besonders im Bereich des Maschinen- und Anlagenbaus neue Möglichkeiten, den Montagearbeiter oder Wartungstechniker bei der Ausführung seiner Arbeit zu unterstützen. Mittels der HFI, die Gesten durch Beschleunigungssensoren erfasst, werden neue Bedienkonzepte und Interaktionselemente dargestellt, die in rauen Umgebungen eingesetzt werden können.

Verband der Elektrotechnik Elektronik Informationstechnik (VDE): Ambient Assisted Living : 4. Deutscher AAL-Kongress mit Ausstellung. Demographischer Wandel-Assistenzsysteme aus der Forschung in den Markt [CD-ROM]. Berlin u.a.: VDE-Verl., 2011, 4 pp. ; Poster 1.12

Das Schwimmen ist eine olympische Sportart und gilt als die derzeit gesündeste Freizeitbeschäftigung mit dem geringsten Verletzungsrisiko. Die Belastung der Gelenke und Knochen ist durch den Auftrieb im Wasser deutlich reduziert. Die Wassertemperatur wirkt anregend auf den Kreislauf und fast alle Muskeln werden bei der Schwimmbewegung genutzt. Besonders für Ältere ist das Schwimmen vorteilhaft, da eine körperliche Aktivität sanft und kostengünstig ausgeführt werden kann. In Rostock wurde in den letzten Jahren mit DiaTrace eine Technologie entwickelt, die es ermöglicht, mittels dreiachsigen Beschleunigungssensoren die Ausübung von körperlicher Aktivität zu messen. Aktivitätsmonitoring im Wasser kann genutzt werden, um Probleme des Schwimmers zu detektieren und somit schnelle Hilfe und Rettung zu erleichtern. Der vorliegende Beitrag beschreibt die Möglichkeiten einer Aktivitätserkennung beim Schwimmen und die damit verbundenen Optionen zum Erkennen einer kritischen Situation und Einleiten von Schutzmaßnahmen (Alarmmeldung, Aufblasen von Notbojen etc.).

Association for Computing Machinery (ACM): The 4th ACM International Conference on PErvasive Technologies Related to Assistive Environments : PETRA 2011. New York: ACM, 2011, 6 p.

In daily life, mobile phones accompany the user permanently and are worn often in the front pocket of the trousers. The sensors included in today's mobile phones can hence be used for ubiquitous assistance. For instance, the acceleration sensor could be used for analysis of the person's bodily activity, or the microphone can be used to analyze the environmental noise levels. A possible sensor fusion provides additional and assured environmental and context information. This work presents new methods of activity recognition by acceleration and sound sensors by means of sensors included in commercially available smart phones during everyday life. We could identify that sounds provide valuable additional information on a user's situation that allow to better asses a person's current context.

1st International Workshop on Frontiers in Activity Recognition using Pervasive Sensing : In Conjunction with Pervasive 2011. Workshop Proceedings [online]. [cited 27 June 2011] Available from: http://di.ncl.ac.uk/iwfar/proceedings-2/ 2011, pp. 36-41

This paper addresses the challenges of flexible acceleration sensor sampling rates of mobile phones and describes the problem of signal reproduction of blurred or distorted signals for physical activity recognition. In this work, low and high order signal interpolation and approximation techniques were analyzed as well as splines to improve the recognition accuracy. The identified best algorithm was implemented to a single point activity recognition system. The signal reconstruction algorithm is used for real time recognition in a standard mobile phone with an integrated acceleration sensor. This phone and its application DiaTrace is able to recognize activity such as resting, walking, cycling, car driving or jumping just by wearing the mobile in the front pocket of a trouser. We could identify that spline algorithm is excellent for activity recognition of smooth and periodic movements, but lower polynomial interpolation has advantages at non periodic and discontinuous movements.

Der vorliegende Tagungsband stellt die Beiträge zum 7. GeoForum in Warnemünde zusammen. Der Verein Geoinformationswirtschaft Mecklenburg-Vorpommern (GeoMV) veranstaltet das zweitägige GeoForum für Vertreter aus Wirtschaft, Politik, Verwaltung, Lehre und Forschung und bietet damit die Möglichkeit zum Erfahrungsaustausch, zur Präsentation von Best-Practice-Beispielen sowie zur Darstellung von neuen technisch-wissenschaftlichen Ergebnissen. Unter dem Motto "Geodateninfrastrukturen: Drehscheibe für Wirtschaft und Verwaltung" soll verdeutlicht werden, dass der Aufbau von Geodateninfrastrukturen derzeit intensiv betrieben wird, zumeist in der öffentlichen Verwaltung. Die einfacher zugängigen Geoinformationen helfen der Wirtschaft innerhalb unternehmerischer Prozesse sowie zur Etablierung neuer Produkte und Dienstleistungen. Die Themenblöcke umspannen: Marine Dateninfrastrukturen, Satellitenbasierte Anwendungen, Internet-GIS-Anwendung, Architektur und Technologie, Logistik und Landwirtschaft.

D'hooge, Jan (Ed.) et al.: Medical Imaging 2011: Ultrasonic Imaging, Tomography, and Therapy : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 12, No. 37. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7968), pp. 79680V-1 - 79680V-12

Registration of intra-operative ultrasound with preoperative CT is highly desirable as a navigational aid for surgeons and interventional radiologists. Image-based solutions generally achieve poor results due to substantially different image appearance of ultrasound and CT. A method is presented that uses surface information and tracked ultrasound to improve registration results. Tracked ultrasound is combined with surface and image-based registration techniques to register ultrasound to CT. Surface data is acquired using an optically tracked range sensor, for example time-of-flight camera. Range data is registered to CT using robust point-set registration; this registration provides an approximate transformation from tracker to CT coordinates. The ultrasound probe is also optically tracked. The probe position and surface-based registration provide a first estimate for the position of the ultrasound image in CT coordinates. This estimate is subsequently refined by a final image-based registration stage. Initial tests using Coherent Point Drift algorithm for registering surface data to CT show favorable results. Tests using both simulated and real time-of-flight range data have good convergence over a wide initial translation and rotation misalignment domain. Preliminary testing using time-of-flight surface data suggests that surface to CT registration may be useful as an initial guess enabling later more precise (but less robust) image based methods for registering ultrasound images to CT. We believe this method will enable image-based algorithms to robustly converge to an optimal registration solution.

Thulasiraman, Parimala (Ed.) et al.: Proceedings 2011 IEEE International Conference on High Performance Computing and Communications : HPCC 2011. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, pp. 78-85

A personal computer can be considered as a one-node heterogeneous cluster that simultaneously processes several application tasks. It can be composed by, for example, asymmetric CPU and GPUs. This way, a high-performance heterogeneous platform is built on a desktop for data intensive engineering calculations. In our perspective, a workload distribution over the Processing Units (PUs) plays a key role in such systems. This issue presents challenges since the cost of a task at a PU is non-deterministic and can be affected by parameters not known a priori. This paper presents a context-aware runtime and tuning system based on a compromise between reducing the execution time of engineering applications - due to appropriate dynamic scheduling - and the cost of computing such scheduling applied on a platform composed of CPU and GPUs. Results obtained in experimental case studies are encouraging and a performance gain of 21.77% was achieved in comparison to the static assignment of all tasks to the GPU.

Schenk, Michael (Ed.): 14. IFF-Wissenschaftstage 2011. Tagungsband : Digitales Engineering und virtuelle Techniken zum Planen, Testen und Betreiben technischer Systeme. Stuttgart: Fraunhofer Verlag, 2011, pp. 191-196

Verteilte Mixed Reality Systeme, d.h. VR/AR-Installationen, die sich an unterschiedlichen Standorten befinden und via Internet vernetzt sind, wurden bislang nur in akademischen Testszenarien eingesetzt. Sie konnten den Sprung in industrielle Nutzung jedoch nicht vollziehen. Im Szenario "VR-Meeting" des BMBF-Projektes AVILUS wurde auf Grundlage des Virtual und Augmented Reality Systems "instantreality" (www.instantreality.de) ein kollaboratives VR-System entwickelt, mit dem Entwicklungsteams an verteilten Standorten in einer virtuellen Konstruktionssitzung zusammenarbeiten. Dabei wurden zum einen Verfahren für eine sichere Datenverteilung realisiert, zum anderen wurden Methoden zur effizienten Protokollierung von verteilten immersiven Konstruktionssitzungen erforscht.

Computertomographische (CT) Ganzkörper-Bilddaten werden im medizinischen Umfeld üblicherweise zur Diagnose von Erkrankungen im Inneren des menschlichen Körpers verwendet, wie zum Beispiel der Diagnose von Krebs. Die automatische Detektion von räumlich markanten Strukturen - sogenannten Landmarken - in CT-Bilddaten stellt die Basis für Segmentierungsverfahren dar, mit deren Hilfe die Lage und Ausdehnung von Organen, wie zum Beispiel der Leber und der Nieren, ermittelt werden kann. Die Landmarkendetektion unterstützt die Analyse und fördert das Verständnis des Bildinhaltes medizinischer Bilddaten. Im Folgenden wird ein Konzept zur automatischen lernbasierten Detekion von dreidimensionalen Landmarken in Ganzkörper-CT-Bilddaten unter Verwendung des maschinellen Lernverfahrens AdaBoost und zweier neuwertiger generischer Bildmerkmale, dem sogenannten 3D-HOG- und 3D-HOGI-Bildmerkmal [Three-dimensional Histogram of Oriented Gradients (and Intensities)], vorgestellt. Es wurden Landmarken-Klassifikatoren für jeweils beide Nieren und die Leber erstellt, mit deren Hilfe die Lage und grobe räumliche Ausdehung der Organe innerhalb eines CT-Datensatzes bestimmt werden können, ohne auf organspezifisches Wissen zurückgreifen zu müssen. Durch Evaluation der Klassifikatoren anhand von 25 Ganz- und Teilkörper-CT-Datensätzen konnte gezeigt werden, dass die Klassifikatoren eine sehr robuste und präzise Detektion der jeweiligen Organe ermöglichen.

Association for Computing Machinery (ACM): The 4th ACM International Conference on PErvasive Technologies Related to Assistive Environments : PETRA 2011. New York: ACM, 2011, 8 p.

The recent success of Nintendo's Wii and multi-touch input devices like the Apple iPhone clearly shows that people are more willing to accept new input device-technologies based on intuitive forms of interaction. Gesture-based input is thus becoming important and even relevant in specific application scenarios. A sensor type especially suited for natural gesture recognition is the capacitive proximity sensor that allows the detection of objects without any physical contact. In this paper we extend the input device taxonomy by Card et al to include this detector category and allow modeling of devices based on advanced sensor units that involve data processing. We have created a prototype based on this modeling and evaluated its use regarding several application scenarios, where such a device might be useful. The focus of this evaluation was to determine the suitability of the device for different interaction paradigms.

Jacko, Julie A. (Ed.): Human-Computer Interaction: Part III : Towards Mobile and Intelligent Interaction Environments. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6763), pp. 147-154

Modern smart environments are comprised of multiple interconnected appliances controlled by a central system. Pointing at devices in order to control them is an intuitive way of interaction, often unconsciously performed when switching TV stations with an infrared remote, even though it is usually not required. However, only a limited number of devices have the required facilities for this kind of interaction since it does require attaching transceivers and often results in the necessity to use multiple remote controls. We propose a system giving a user the ability to intuitively control arbitrary devices in smart environments by identifying the appliance an interaction device is pointed at and providing means to manipulate these. The system is based on identifying the position and orientation of said interaction device, registering these values to a virtual representation of the physical environment, which is used to identify the selected appliance. We have created a prototype interaction device that manipulates the environment using gesture-based interaction.

Computer Graphics Forum, Vol.30 (2011), 3, pp. 891-900

Exploration and selection of data descriptors representing objects using a set of features are important components in many data analysis tasks. Usually, for a given dataset, an optimal data description does not exist, as the suitable data representation is strongly use case dependent. Many solutions for selecting a suitable data description have been proposed. In most instances, they require data labels and often are black box approaches. Non-expert users have difficulties to comprehend the coherency of input, parameters, and output of these algorithms. Alternative approaches, interactive systems for visual feature selection, overburden the user with an overwhelming set of options and data views. Therefore, it is essential to offer the users guidance in this analytical process. In this paper, we present a novel system for data description selection, which facilitates the user's access to the data analysis process. As finding of suitable data description consists of several steps, we support the user with guidance. Our system combines automatic data analysis with interactive visualizations. By this, the system provides a recommendation for suitable data descriptor selections. It supports the comparison of data descriptors with differing dimensionality for unlabeled data. We propose specialized scores and interactive views for descriptor comparison. The visualization techniques are scatterplot-based and grid-based. For the latter case, we apply Self-Organizing Maps as adaptive grids which are well suited for large multi-dimensional data sets. As an example, we demonstrate the usability of our system on a real-world biochemical application.

In dieser Arbeit werden wesentliche Aspekte zum Thema der Analyse mentaler Zustände aufgezeigt. Es wird deutlich gemacht, welche Arten von physiologischen Daten in aktuellen Forschungen genutzt und welche Anforderungen an sie gestellt werden. Weiterhin wird die Wichtigkeit verschiedener Biosignale erläutert und wie sie in der Praxis aufgezeichnet werden. Der Prozess der automatischen Erfassung des mentalen Zustandes wird besprochen und die verschiedenen Möglichkeiten zur konkreten Ausführung beschrieben. Letztlich ist eine Übersicht über vergangene Studien aufgeführt worden.

Diese Arbeit beschäftigt sich mit der Frage, wie es möglich ist, den Zustand eines Fahrers bestmöglich zu erfassen. Die Erkennung des aktuellen Zustandes einer Person, in Form einer aktuell empfundenen Emotion, stellt für jemand anderen, welcher dies beurteilen muss, eine schwierige und sehr komplexe Aufgabe dar. Nicht umsonst existieren ganze Berufsfelder und -gruppen, die sich mit der Frage beschäftigen, was ein Mensch in einer erlebten Situation fühlte oder gerade fühlt. Wesentlich schwieriger ist dieses Problem für eine Maschine, welche sich nur auf mathematische Methoden und Sensoren, die die zu betrachtende Person beobachten, verlassen kann. Die Informatik brachte das Teilgebiet Affektive Computing hervor, um die Emotionen eines Nutzers bei gewissen Gestaltungen der Mensch-Maschinen-Kommunikation mit einzubeziehen. Dabei bedient sich dieses Gebiet theoretischer Grundlagen der Emotionspsychologie als auch der Emotionstheorie, um zum Beispiel zu ergründen, was eine Emotion ist, wie sie ausgelöst oder beeinflusst werden kann. Heutzutage existiert eine große Menge an Erfahrungen und Wissen über Zustandsvermutungen, ebenso ist die Technik der Gegenwart wie nie zuvor dazu in der Lage, die äußere Umwelt aufzunehmen, und dennoch ist es eine große Herausforderung, dieses Teilgebiet der Informatik vollständig zu erfassen. Ein System, welches in einem Auto integriert ist, soll den Zustand einer Person bestmöglich überwachen und Aussagen über die aktuelle Gemütslage treffen können. Vorstellbar wäre, dass es in Stresssituationen beruhigend wirkt oder bei Langeweile ablenkt, um seine Konzentration wieder zu erhöhen. Jedoch wirft diese Vorstellung eine ganze Reihe Fragen auf, etwa, wie genau erfasst dieses System die äußere Umwelt und in welchem Maße ist das überhaupt nötig. Zudem muss geklärt werden, wie diese Umwelt analysiert und interpretiert werden muss, um Rückschlüsse auf einen Gemütszustand führen zu können. Um diese Fragen beantworten zu können, werden Mittel und Wege, in Form von geeigneter Sensorik, vorgestellt, um sich ein Bild von den äußeren Gegebenheiten machen zu können. Theoretische Hintergründe werden beleuchtet, damit Daten aus der Sensorik analysiert und schließlich eine Zustandserkennung generiert werden können. Diese Arbeit wurde in Zusammenarbeit mit einem Automobilzulieferer entwickelt, welcher das Ziel verfolgt, mittels am Lenkrad angebrachter Sensoren, den Zustand eines Fahrers bestmöglich zu erfassen. Auf Grundlage dieses erfassten Zustandes wäre es dann vorstellbar, dass ein entsprechendes System helfend eingreifen kann. So soll diese Arbeit erste Grundlagen schaffen und theoretische Hintergründe für diese Problemstellung bereitstellen als auch eine praktische Umsetzung, in Form einer Implementierung, umsetzen.

Smith, Michael J. (Ed.) et al.: Human Interface and the Management of Information: Part I : Interacting with Information. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6771), pp. 528-537

Existing reference models for recommender systems are on an abstract level of detail or do not point out the processes and transitions of recommendation systems. However, this information is relevant for developers to design or improve recommendation systems. Even so, users need some background information of the calculation process to understand the process and accept or configure these systems proper. In this paper we present a comprehensive reference model for recommender systems which conjuncts the recommendation processes on an adequate level of detail. To achieve this, the processes of content-based and collaboration-based systems are merged and extended by the transitions and phases of hybrid systems. Furthermore, the algorithms which can be applied in the phases of the model are examined to identify the data flow between these phases. With our model those information of the recommendation calculation process can be identified, which encourages the traceability and thus the acceptance of recommendations.

The proceedings of the BIOSIG 2011 include scientific contributions of the annual conference of the Special Interest Group on Biometrics and Electronic Signatures (BIOSIG) of the Gesellschaft für Informatik (GI). The conference took place in Darmstadt, 08.-09. September 2011. Within two days mainly the advances of biometrics research and new developments in the biometric application fields beyond security applications have been presented and discussed by biometrics and security professionals.

Stephanidis, Constantine (Ed.): Universal Access in Human-Computer Interaction: Part I : Design for All and eInclusion. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6765), pp. 20-29

Nowadays a wide range of input devices are available to users of technical systems. Especially modern alternative interaction devices, which are known from game consoles etc., provide a more natural way of interaction. But the support in computer programs is currently a big challenge, because a high effort is to invest for developing an application that supports such alternative input devices. For this fact we made a concept for an interaction system, which supports the use of alternative interaction devices. The interaction-system consists as central element a server, which provides a simple access interface for application to support such devices. It is also possible to address an abstract device by its properties and the interaction-system overtakes the converting from a concrete device. For realizing this idea, we also defined a taxonomy for classifying interaction devices by its interaction method and in dependence to the required interaction results, like recognized gestures. Later, by using this system, it is generally possible to develop a user-centered system by integrating this interaction-system, because an adequate integration of alternative interaction devices provides a more natural and easy to understand form of interaction.

Stephanidis, Constantine (Ed.): Universal Access in Human-Computer Interaction: Part I : Design for All and eInclusion. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6765), pp. 317-326

Searching information on web turned to a matter of course in the last years. The visualization and filtering of the results of such search queries plays a key-role in different disciplines and is still today under research. In this paper a new approach for classifying the search intention of users' is presented. The approach uses existing and easy parameters for a differentiation between explorative and targeted search. The results of the classification are used for a differentiated presentation based on graphical visualization techniques.

Candel Torres, Ignacio (Ed.) et al.: ICERI 2011. Proceedings : 4th International Conference of Education, Research and Innovation. Valencia: IATED, 2011, pp. 002050-002057

Today's society especially in the western world is marked by life-long learning, because of an increasing technology development primary in Information Communication Technologies and because of an increasing need of up-to-date experts. In contrast to urban regions, the education in rural areas often is only possible virtually. Therefore, a various number of e-Learning Systems exist, that are oftentimes hard to use especially for less computer experienced users. For providing a facilitated access to e-Knowledge in such e-Learning Systems this paper describes an approach for developing an easy usable and understandable portal that furthermore aims to achieve a positive emotional feeling. These emotional aspects, subsumed in user experience, are a necessary factor if the user should be motivated and supported during his learning process.

Candel Torres, Ignacio (Ed.) et al.: ICERI 2011. Proceedings : 4th International Conference of Education, Research and Innovation. Valencia: IATED, 2011, pp. 001348-001354

The requirements on today's employees have been changed in the past. Today the western world needs significant more well educated employees, often named as experts. To be attractive for the job market the employees have to stay up-to-date and to improve their skills continuously, so lifelong-learning becomes important for the business carrier. But especially this advanced learning becomes difficult for people in rural regions. The existing strategies like improving skills on adult education centres is not appropriated for the rural population because of e.g. travelling costs. To solve this discriminating circumstance is the main goal of the RURALeNTER project. The project aims to develop a new approach how advanced education can be provided to the rural population by using modern technologies over internet. The effective use of specifically to the requirements of rural population developed internet tools enables even for beginners the possibility to be similar effective as the advanced training that is provided in urban regions in the traditional form. The resulting approach was tested and used amongst others in Spain, Austria and Romania.

Kurosu, Masaaki (Ed.): Human Centered Design : Second International Conference: HCD 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6776), pp. 491-499

The Semantic Web is a powerful technology for organizing the data in our information based society. The collection and organization of information is an important step for showing important information to interested people. But the usage of such semantic-based data sources depends on effective and efficient information visualizations. Currently different kinds of visualizations in general and visualization metaphors do exist. Many of them are also applied for semantic data source, but often they are designed for semantic web experts and neglecting the normal user and his perception of an easy useable visualization. This kind of user needs less information, but rather a reduced qualitative view on the data. These two aspects of large amount of existing data and one for normal users easy to understand visualization is often not reconcilable. In this paper we create a concept for a visualization to show a bigger set of information to such normal users without overstraining them, because of layer-based data visualization, next to an integration of a Focus and Context metaphor.

Verband der Elektrotechnik Elektronik Informationstechnik (VDE): Ambient Assisted Living : 4. Deutscher AAL-Kongress mit Ausstellung. Demographischer Wandel-Assistenzsysteme aus der Forschung in den Markt [CD-ROM]. Berlin u.a.: VDE-Verl., 2011, 10 pp. ; Paper 5.3

Die Verwendung von modernen Interaktionsmethoden und Geräten erlaubte eine natürlichere und intuitive Interaktion. Gegenwärtig haben lediglich die Smartphones und Spielekonsolen großen Absatz, welche eine gestenbasierte Interaktion unterstützen. Dies geht einher, dass solche Geräte nicht nur von technisch versierten Konsumenten gekauft werden. Die Interaktion mit solchen Geräten gestaltet sich so einfach, dass oftmals auch ältere Personen mit diesen spielen oder arbeiten. Insbesondere ältere Personen sind häufig gehandicapt, so haben sie oftmals Probleme kleinere Text zu lesen, wie sie häufig auf Fernbedienungen gedruckt sind. Ebenso neigen sie dazu, schnell überfordert zu sein, so dass gerade größere technische Systeme keine Hilfe sind. Wenn die Geräte mit Gesten steuerbar sind, sind die genannten Probleme oftmals vermeidbar. Um aber eine intuitive und einfache Gesteninteraktion zu ermöglichen, müssen entsprechend verständliche und nachvollziehbare Gesten unterstützt werden. Aus diesem Grund versuchen wir in diesem Paper intuitive Gesten für gängige Interaktionsszenarien an computerbasierten Systemen für den Einsatz in unterstützenden Umgebungen zu identifizieren. Im Rahmen der Evaluation sollen die Probanden hierfür ihre bevorzugten Gesten für die verschiedenen Interaktionsszenarien einbringen. Auf Grundlage der Ergebnisse kann später ein intuitiv bedienbares System, unter Verwendung eines beschleunigungssensorbasierten Geräts, entwickelt werden, mit welchem die Nutzer auf intuitive Weise kommunizieren können.

Datenschutz & Datensicherheit, Vol.35 (2011), 3, pp. 183-191

Biometrische Systeme sind zwar technisch weit ausgereift und bieten heute Erkennungsleistungen, die noch vor 10 Jahren unerreichbar waren. Jedoch ist ein weit verbreiteter Einsatz von biometrischen Authentisierungsverfahren durch Bedenken hinsichtlich des notwendigen Schutzes von Referenzdaten gebremst. Eine sichere und datenschutzfreundliche Verarbeitung von biometrischen Daten wird möglich, wenn Template Protection Verfahren zum Einsatz kommen. Diese Verfahren wurden in einer wissenschaftlichen Studie (BioKeyS-Pilot-DB Teil 2) des Bundesamtes für Sicherheit in der Informationstechnik (BSI) untersucht. Dieser Artikel berichtet über die Ergebnisse im Projekt. Er zeigt auf, wie Mechanismen zum Schutz von biometrischen Daten mit Zusatzinformationen z.B. Passwörtern verknüpft und wie die Verfahren auch in Identifikationssystemen eingesetzt werden können.

Ziel dieser Arbeit ist das optische Erkennen großer technischer Strukturen durch Verfahren der 3D-Rekonstruktion und 3D-Segmentierung. Dazu werden gängige Verfahren vorgestellt und verfügbare Lösungen zur 3D-Rekonstruktion verglichen, um so einen Überblick über den Stand der Technik zu ermöglichen. Eine darauf aufbauende Auswahl von verfügbaren Technologien, zusammen mit etablierten Segmentierungs-Verfahren aus Bildverarbeitung und Data Mining, angewandt auf den 3D-Raum, ergeben eine umfassende Prozesskette zur 3D-Rekonstruktion und 3D-Segmentierung, welche die gestellten Anforderungen erfüllt. Segmentiert wurde auf Punktdaten, da die 3D-Rekonstruktionsergebnisse hier genauer sind. Texturierte Drahtgittermodelle, welche andere Algorithmen zur Segmentierung ermöglicht hätten, wurden nicht verwendet. Die 3D-Segmentierung wird dazu mit einem eigenen Programm, welches unter Verwendung von modernen Bibliotheken zur Visualisierung und Interaktion, vereint unter einer intuitiv zu bedienenden Oberfläche, prototypisch umgesetzt. Für die 3D-Segmentierung werden verschiedene, aus dem 3D-Modell extrahierbare, Informationen genutzt, in ihrer Eignung bewertet und kombiniert.

IEEE Communications Society: 2011 International Conference on Internet Computing and Information Services : ICICIS 2011. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, pp. 152-155

In the clinical practice of diagnosis and treatment of liver disease, how to effectively represent and analyze the vascular structure has been a widely studied topic for a long time. In this paper, we propose a method for the three-dimensional skeletal graph generation of liver vessels using 3D thinning algorithm and graph theory. First of all, the principal methods for skeletonization are introduced, followed by their comparative analysis. Secondly, the 3D thinning-based skeletonization method together with a filling hole pre-processing on liver vessel image is employed to form the liver skeleton. A graph-based technique is then employed on the skeleton image to efficiently form the liver vascular graph. The thinning-based liver vessel skeletonization method was evaluated on liver vessel images with other two kinds of skeletonization approaches to show its effectiveness and efficiency.

Fendel, E.M. (Ed.) et al.: 28th Urban Data Management Symposium UDMS at 40 Years: Making Contributions to the Future. Beijing: ISPRS, 2011. (The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XXXVIII-4/C21), pp. 7-12

In recent years the technology and workflow for producing and management of large 3D urban models has been established and widely been used. Standards such as CityGML enable the modelling and exchange of semantically enriched multi-purpose 3D urban models for applications like urban planning, public participation, environmental simulation and navigation. However, data quality management is essential to control and enhance the quality of these models in order to be able to meet the needs of the aforementioned applications. Quality management should be performed throughout the whole lifecycle of geospatial datasets - from data acquisition to processing, analysis and visualisation. In this paper, we therefore focus on the integration of a quality management software module into a 3D geospatial data server. First results of a prototype system developed at HFT Stuttgart together with Fraunhofer IGD will be presented in this paper as a starting point for further research into the field of quality management of 3D city models.

Lukas, Uwe von (Ed.) et al.: Go-3D 2011: Computergraphik für die Praxis : Tagungsband zur Konferenz Go-3D 2011. Stuttgart: Fraunhofer Verlag, 2011, pp. 75-94

Bodeneffektfahrzeuge nutzen den gleichnamigen Effekt aus, um sich mit hoher Geschwindigkeit über das Wasser zu bewegen. Sie sind als Boote klassifiziert und erreichen dennoch Geschwindigkeiten von bis zu 200 km/h. Diese hohe Geschwindigkeit und das vergleichsweise instabile Bewegungsverhalten erfordern ein Training am Simulator. Ziel im Projekt MARSPEED war daher die Entwicklung eines Trainingssimulators für maritime Hochgeschwindigkeitsfahrzeuge. Vom Fraunhofer IGD wurde in Zusammenarbeit mit der Universität Rostock und der Hochschule Wismar in diesem Verbundprojekt eine Architektur zur Nahe-Echtzeit-Verbindung von Simulation, Visualisierung und Lern-Management konzipiert und umgesetzt. Außerdem wurde ein visuelles System entwickelt, bestehend aus Visualisierung der Fahrersicht, Anzeigen der Instrumente (Dash-board) sowie Ankopplung der Eingabegeräte. Sowohl begleitend als auch abschließend wurden die (Teil-)Ergebnisse aus technischer, didaktischer und ergonomischer Sicht evaluiert. Als Ergebnis liegen ein Konzept und die prototypische Umsetzung eines skalierbaren Trainingssimulators vor. Kernstück ist die echtzeitfähige, realitätsnahe Simulation und Visualisierung von Bodeneffektfahrzeugen. Es wurde weiterhin gezeigt, dass eine enge Kopplung des Simulators zu CBT (Computer Based Training) sinn-voll zur Umsetzung moderner Blended Learning-Konzepte genutzt werden kann.

3D-COFORM workshop: The project aims to establish 3D documentation as an affordable, practical and effective mechanism for the documentation and visualisation of tangible cultural heritage. LINKSCEEM 2 workshop: LinkSCEEM2 aims to develop a high performance computing eco-system in the Eastern Mediterranean region by interlinking and coordinating regional compute, data and visualisation resources to form an integrated e-platform. V-must presentation: V-MusT is a new EU FP7-funded network of excellence that aims to provide the heritage sector with the tools and support to develop virtual museums that are educational, enjoyable, long-lasting and easy to maintain. The project started at the beginning of 2011.

VAST is a primary event, enabling on the one hand the interaction between Archaeologists, Cultural Heritage professionals and Information and Communication Technology (ICT) scientists, and on the other hand the dissemination of innovative solutions for the preservation and conservation of the world heritage. VAST is a unique scenario for the demonstration of state of the art research in the areas of data acquisition and processing, metadata handling, and presentation, as well as for the communication and understanding of practitioners' experience in the field. The VAST platform boosts the establishment of 3D documentation and digital libraries as standard instruments for the integration of 3D digital assets within professional environments, fostering the scholarly research and the public engagement.

Solomonides, Tony (Ed.): Twenty-Fourth IEEE Symposium on Computer-Based Medical Systems and HealthGrid Conference : CBMS 2011 + HG 2011. Los Alamitos, Calif.: IEEE Computer Society, 2011, 6 p.

The proper separation of hepatic veins is crucial for discriminative visualization during surgical planning and intraoperative navigation, automated analysis and liver segment approximation. However, due to several reasons liver and portal vein may be connected at some points and may contain loops. In this work, we propose a novel graphbased method to separate interconnected hepatic veins. Furthermore, we show how to transfer the graph-based separation results back to the imaging data to improve the initial segmentation and discriminate portal and liver vein. In addition, we propose a majority voting operation to correct some segmentation imperfections. Promising qualitative and quantitative evaluation results are presented.

Dawant, Benoit M. (Ed.) et al.: Medical Imaging 2011: Image Processing. Part Two : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 12, No. 31. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7962), pp. 79622S-1 - 79622S-7

The key challenge in tumor segmentation is to determine their exact location and volume. Difficulties arise because of low intensity boundaries, varying shapes and sizes. Furthermore, tumors can be located everywhere in the liver. Interactive segmentation methods seem to be the most appropriate in terms of reliability and robustness. In this work, we use a graph-cut based method to interactively segment tumors. However, complexity of the underlying graphs is enormous for clinical 3D datasets. We propose a method to identify automatically a region of interest using a coarse resolution image, which is then used to construct a reduced graph for final segmentation in the original image in full resolution. We compared our results to ground truth segmentations done by experts. Our results suggest that accuracy is comparable to other approaches. The average overlap was 80%, the average surface distance 0.73 mm and the average maximum surface distance 5.31 mm.

We present approaches for visualizing uncertainty in an application context through techniques for the visualization of uncertainty. We also describe methods for the reduction of the complexity of the visualization to avoid cognitive overload. Uncertainty in both natural and man-made structures under ground is thus communicated to the user in an appropriate, non threatening manner. The methods were evaluated during an end-user workshop of the research project DeepCity3D. The results of this workshop have led to various extensions to our uncertainty visualization approach in urban management

In dieser Arbeit wird ein klassifikator-basierter Ansatz vorgestellt und evaluiert. Er ermöglicht es, mit den Daten einer monokularen Kamera die Kopfpose von Personen, die als Indikator der Blickrichtung und Aufmerksamkeit verwendet werden kann, diskret zu bestimmen. Der Raum aller Kopfposen, der aus den Kopfbewegungen von links nach rechts (Zeilen) und von oben nach unten (Spalten) besteht, wird mittels eines Rasters diskret in Klassen unterteilt. Der verwendete Klassifikator ist eine lineare Support Vector Machine. Als Deskriptoren werden verkleinerte Vorschaubilder in Farbe, Graustufen und Gradienten, sowie die Histogram of oriented gradients (HOG) evaluiert. Sie wurden für jede Klasseneinteilung getestet und ihre Ergebnisse ausgewertet. Es wurden drei verschiedene Poseneinteilungen vorgenommen: Fünf (1 x 5), neun (3 x 3) und 15 (3 x 5)Klassen. Im ersten Durchlauf wurde der Klassifikator für fünf (1 x 5) mögliche Kopfposen getestet. Anschließend wurde die Anzahl der möglichen Kopfposen auf neun (3 x 3) erhöht. Und zuletzt wurde eine Kopfposenanzahl von 15 (3 x 5) Posen getestet. Zur Evaluierung wurde die Pointing '04 Bilderdatenbank verwendet, wobei in einem Vorbereitungsschritt basierend auf Template Matching der relevante Kopfbereich aus den Bildern extrahiert wurde. Mit Hilfe der Evaluierung wird gezeigt werden, dass der HOG-Deskriptor mit Abstand die besten Ergebnisse erzielt, um erfolgreich die Kopfpose einer Person zu bestimmen. Bei einer Einteilung in f unf Kopfposen wurde die beste Klassifizierungsrate von 80,6% durch den HOG-Deskriptor erreicht. Wie zu erwarten, sinkt die Klassfikationsgenauigkeit bei steigender Kopfposenanzahl ab. Mit einer erhöhten Anzahl an Kopfposen erbrachte der HOG-Deskriptor, bei neun Klassen mit einer Genauigkeit von 72,7% und bei 15 Klassen mit einer Genauigkeit von 66,0%, das beste Resultat.

IEEE Engineering in Medicine and Biology Society (EMBS): 2011 IEEE International Symposium on Biomedical Imaging: From Nano to Macro : ISBI 2011. New York: IEEE Press, 2011, pp. 2076-2082

Pancreas segmentation in 3-D computed tomography (CT) data is of high clinical relevance, but extremely difficult since the pancreas is often not visibly distinguishable from the small bowel. So far no automated approach using only single phase contrast enhancement exist. In this work, a novel fully automated algorithm to extract the pancreas from such CT images is proposed. Discriminative learning is used to build a pancreas tissue classifier that incorporates spatial relationships between the pancreas and surrounding organs and vessels. Furthermore, discrete cosine and wavelet transforms are used to build computationally inexpensive but meaningful texture features in order to describe local tissue appearance. Classification is then used to guide a constrained statistical shape model to fit the data. Cross-validation on 40 CT datasets yielded an average surface distance of 1.7 mm compared to ground truth which shows that automatic pancreas segmentation from single phase contrast enhanced CT is feasible. The method even outperforms automatic solutions using multiple-phase CT both in accuracy and computation time.

Dawant, Benoit M. (Ed.) et al.: Medical Imaging 2011: Image Processing. Part One : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 12, No. 31. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7962), pp. 796212-1 - 796212-6

The detection and assessment of many hepatic diseases is based on examination of multiphase liver CT volumes. Since phases contain complementary information, registration enables the radiologist to fuse the needed information for diagnosis or operation planning. This work presents a novel multi-stage approach for automatic registration of the liver in contrast enhanced CT volumes. Unlike other methods, our approach is based on automatic pre-segmentation of the liver in the different phases. Using the resulting shape information the volumes are coarsely registered using a landmark-based registration. Subsequently, deformations caused by the patient's breathing are compensated by an elastic Demons algorithm with a boundary distance based speed function. This allows for a high accuracy natural deformation without having to rely on error-prone extraction and matching of the liver's internal structure in complementary phases. Furthermore, since shape information is given, surrounding structures can be omitted which significantly speeds up registration. We evaluated our method using 22 CT volumes from 11 patients. The matching quality of outer shape and internal structures was validated by radiology experts. The high quality results of our approach suggest its applicability in clinical practice.

VAR. Virtual Archaeology Review [online], Vol.2 (2011), 4, pp. 95-103. [cited 30 November 2011] Available from: http://www.varjournal.es/doc/varj02 004 09.pdf

A new technology is on the rise that allows the 3D-reconstruction of Cultural Heritage objects from image sequences taken by ordinary digital cameras. We describe the first experiments we made as early adopters in a community-funded research project whose goal is to develop it into a standard CH technology. The paper describes in detail a step-by-step procedure that can be reproduced using free tools by any CH professional. We also give a critical assessment of the workflow and describe several ideas for developing it further into an automatic procedure for 3D reconstruction from images.

The Fraunhofer Institute for Computer Graphics Research IGD with offices in Darmstadt as well as in Rostock, Singapore, and Graz, the partner institutes at the respective universities, the Interactive Graphics Systems Group of Technische Universität Darmstadt, the Computergraphics and Communication Group of the Institute of Computer Science at Rostock University, Nanyang Technological University (NTU), Singapore, and the Visual Computing Cluster of Excellence of Graz University of Technology, cooperate closely within projects and research and development in the field of Computer Graphics. The "Selected Readings in Computer Graphics 2010" consist of 45 articles selected from a total of 186 scientific publications contributed by all these institutions. All articles previously appeared in various scientific books, journals, conferences and workshops, and are reprinted with permission of the respective copyright holders. The publications had to undergo a thorough review process by internationally leading experts and established technical societies. Therefore, the Selected Readings should give a fairly good and detailed overview of the scientific developments in Computer Graphics in the year 2010. They are published by Professor Dieter W. Fellner, the director of Fraunhofer Institute for Computer Graphics Research IGD in Darmstadt, at the same time professor at the Department of Computer Science at Technische Universität Darmstadt, and professor at the Faculty of Computer Science at Graz University of Technology.

The Fraunhofer Institute for Computer Graphics Research IGD with offices in Darmstadt as well as in Rostock, Singapore, and Graz, the partner institutes at the respective universities, the Interactive Graphics Systems Group of Technische Universität Darmstadt, the Computergraphics and Communication Group of the Institute of Computer Science at Rostock University, Nanyang Technological University (NTU), Singapore, and the Visual Computing Cluster of Excellence of Graz University of Technology, cooperate closely within projects and research and development in the field of Computer Graphics. The "Selected Readings in Computer Graphics 2010" consist of 45 articles selected from a total of 186 scientific publications contributed by all these institutions. All articles previously appeared in various scientific books, journals, conferences and workshops, and are reprinted with permission of the respective copyright holders. The publications had to undergo a thorough review process by internationally leading experts and established technical societies. Therefore, the Selected Readings should give a fairly good and detailed overview of the scientific developments in Computer Graphics in the year 2010. They are published by Professor Dieter W. Fellner, the director of Fraunhofer Institute for Computer Graphics Research IGD in Darmstadt, at the same time professor at the Department of Computer Science at Technische Universität Darmstadt, and professor at the Faculty of Computer Science at Graz University of Technology.

International Journal of Spatial Data Infrastructures Research, Vol.6 (2011), pp. 234-260

Data harmonisation is a key prerequisite for an efficient and meaningful combination of heterogeneous information in cross-border applications and spatial data infrastructures. This is also the main objective of the INSPIRE Directive which has entered its implementation phase. Data Specifications for INSPIRE Annex I data themes have been published containing harmonised, pan- European data models and a number of other requirements. Data providers across Europe face the challenge of transforming their legacy data to comply with these Data Specifications. This paper presents results of the European project HUMBOLDT. Data harmonisation requirements identified in nine scenarios covering a wide range of application domains and using heterogeneous data from a number of European countries are illustrated. Processes required to achieve data harmonisation are described from an application point of view. The open-source software framework for data harmonisation and services integration developed in the project is introduced and its use in two application scenarios is demonstrated.

Geoinformatica, Vol.15 (2011), 1, pp. 191-221. First published 9 October 2009 as OnlineFirst; DOI 10.1007/s10707-009-0093-4

Discovery of suitable web services is a crucial task in Spatial Data Infrastructures (SDI). In this work, we develop a novel approach to the discovery of geoprocessing services (WPS). Discovery requests and Web Processing Services are annotated as conjunctive queries in a logic programming (LP) language and the discovery process is based on Logic Programming query containment checking between these descriptions. Besides the types of input and output, we explicitly formalise the relation between them and hence are able to capture the functionality of a WPS more precisely. The use of Logic Programming query containment allows for effective reasoning during discovery. Furthermore, the relative simplicity of the semantic descriptions is advantageous for their creation by non-logics experts. The developed approach is applicable in the Web Service Modeling Framework (WSMF), a state-of-the-art semantic web service framework.

Der vorliegende Tagungsband stellt die Beiträge zum 6. Rostocker eGovernment Forum in Warnemünde zusammen. Die Hansestadt Rostock und der GeoMV e.V. veranstaltet jährlich das eintägige Forum für Vertreter aus Wirtschaft, Verwaltung, Lehre und Forschung. Diese Konferenz bietet traditionell die Möglichkeit zum Erfahrungsaustausch und zur Präsentation von Best-Practice-Beispielen sowie zur Darstellung von technisch-wissenschaftlichen Ergebnissen. Unter dem Motto " Nachhaltiges eGovernment: Herausforderung und Notwendigkeit!" steht in diesem Jahr stärker das Change Management und die notwendige Anwendung langfristiger Ansätze innerhalb der jeweiligen Verwaltungs-Prozesse im Vordergrund. Die Themenblöcke im Tagungsband umspannen: Wissensmanagement, Bürgerbeteiligungs- und Sozial Software-Ansätze, GeoProcessing sowie Steuerung von Verwaltungsprozessen. Zudem sind die Firmenprofile der Sponsoren dieser Veranstaltung im Tagungsband enthalten.

Semantisch annotierte Daten spielen eine immer wichtigere Rolle in zukünftigen Systemen zur Informationsdarstellung und Wissensaneignung. Besonders das Linked Open Data (LOD) Format erfährt in neuerer Zeit ein erstaunliches Wachstum. Trotz dieser Entwicklung werden die Vorteile semantischer Daten bisher von den wenigsten Internetanwendungen aufgegriffen. Diese Arbeit beschreibt einen neuen Ansatz zur benutzerzentrierten, datenadaptiven semantischen Visualisierung für Suchergebnisse aus Linked Open Data Anwendungen. Die erarbeiteten Konzepte machen von den Vorteilen semantischer Daten gebrauch, vereint mit der dynamischen Kombination von Darstellungstechniken aus dem Bereich der Informationsvisualisierung. Die Arbeit startet mit einer Beschreibung grundlegender Konzepte der Informationsvisualisierung, semantischer Daten und einer Diskussion über die Vor- und Nachteile von Visualisierungsmethoden speziell für semantische Daten. Im folgenden Kapitel werden aktuelle Methoden aus der Informationsvisualisierung vorgestellt und wichtige LOD-Systeme beschrieben. Der Vergleich und die Bewertung aktueller Anwendungen zur Visualisierung von semantischen Daten bilden den Kern dieses Kapitels. Danach folgt die Beschreibung des neuen Konzepts, das die charakteristische Struktur von LOD-Systemen mit den Vorteilen aktueller Visualisierungtechniken vereint. Das Ergebnis ist ein Visualisierungssystem, das die Komposition verschiedener Visualisierungstechniken an die zugrunde liegende Datenstruktur anpasst und so die Vorteile beider Bereiche miteinander verbindet. Die Beschreibung der Implementierung eines Prototypen folgt, an dessen Beispiel die Vorteile des neuen Systems erläutert werden. Die Zusammenfassung der erarbeiteten Konzepte zusammen mit einem Ausblick auf weitere Forschungsthemen, basierend auf den vorgestellten Ansätzen, schließen die Arbeit ab.

ACM SIGGRAPH: Proceedings Web3D 2011 : 16th International Conference on 3D Web Technology. New York: ACM Press, 2011, pp. 71-80

Until recently, depth sensing cameras have been used almost exclusively in research due to the high costs of such specialized equipment. With the introduction of the Microsoft Kinect device, real-time depth imaging is now available for the ordinary developer at low expenses and so far it has been received with great interest from both the research and hobby developer community. The underlying OpenNI framework not only allows to extract the depth image from the camera, but also provides tracking information of gestures or user skeletons. In this paper, we present a framework to include depth sensing devices into X3D in order to enhance visual fidelity of X3D Mixed Reality applications by introducing some extensions for advanced rendering techniques. We furthermore outline how to calibrate depth and image data in a meaningful way through calibration for devices that do not already come with precalibrated sensors, as well as a discussion of some of the OpenNI functionality that X3D can benefit from in the future.

Digital Engineering Magazin, (2011), 8, pp. 34-35

Der intensive Austausch von Modelldaten im Schiffbau zwischen Zulieferer und Werft sowie zwischen verschiedenen Anwendungen innerhalb der Werft ist für eine moderne virtuelle Produktentwicklung besonders wichtig. Viele Werften halten die Daten gegenwärtig in verschiedene Quell- und Zielsystemen vor, was zu einer Vielzahl von Schnittstellen ohne standardisierte Konvertierungswege führt. Dies erschwert es, die Daten in benötigter Qualität und notwendigem Umfang in die Systeme der Werft zu integrieren. Abhilfe kann ein neutrales Datenformat schaffen.

Dem Austausch von Produktdaten zwischen verschiedenen Anwendungen kommt im Zuge einer stetig ansteigenden Nutzung der Daten im gesamten Produktlebenszyklus eine immer stärkere Bedeutung zu. Ein wesentlicher Faktor für den reibungs- und verlustlosen Austausch ist dabei das Austauschformat. Dieser Bericht soll einen Überblick über die Fähigkeiten neutraler Visualisierungsformate und korrespondierender Software (Exporter und Konverter) geben. Im Fokus stehen im Engineering-Kontext relevante Datenformate für die prozessübergreifende Nutzung der Daten. Ein weiteres Augenmerk liegt auf dem Datenaustausch mit Zulieferern und der Nutzung für Virtual-Reality-Anwendungen. Basierend auf der Befragung verschiedener Werften und Zulieferer werden relevante Aspekte ermittelt und eine Kriterienmatrix aufgestellt, mit der die Eignung der Formate über eine Gewichtung bewertet wird. Außerdem wird eine Matrix zur Verfügbarkeit der Konverter für den Im- und Export der Formate in und aus Autorensystemen aufgestellt und ergänzend die Qualität exemplarisch durchgeführter Konvertierungen dargestellt. Abschließend werden Empfehlungen für die Formate im gegebenen Umfeld ausgesprochen.

Ercim News, (2011), 87, p. 47

In a move to improve the AAL research program, the AAL community has decided to make suggestions to the EC policy makers who are currently defining a strategic imlpementation plan for a European innovation partnership dedicated to active healthy ageing. This contribution has taken the shape of a declaration made public during the AAL forum in Lecce (September 2011). The declaration organisation committee explains the context of this initiative.

Ercim News, (2011), 87, pp. 44-45

universAAL is a European research project that aims at creating an open platform and standards which will make it technically feasible and economically viable to develop Ambient Assisted Living solutions. The project follows an open source license model and preliminary results are already available.

Ercim News, (2011), 87, pp. 43-44

Ambient Assisted Living (AAL) has great potential to positively influence the lives of many people. But the impacts so far have been less than hoped, partly due the fragmentation of research efforts and the lack of a standardized approach for developers. To address this, we are forming AALOA (the AAL Open Association), and invite you to join in our efforts.

Dense 3D Reconstruction of environments is important for various applications like augmented reality, artefact digitization and object classification. Object classification in particular allows for scene understanding. This work proposes the development of a pipeline for image based 3D reconstruction and object recognition. The 2D images under consideration are the inside out images of the interior of a room. A dense 3D reconstruction allows the description of the room as point clouds on which the object recognition algorithms are implemented. To allow for flexibility in terms of image acquisition methods, the algorithm is robust to the type of image input as well as the number of images. Matching algorithms like Scale Invariant Feature Transform (SIFT) provide accurate correspondences while Structure from Motion (SFM) algorithms use these correspondences to estimate precise camera pose and Multi-view Stereo (MVS) methods take images with pose as input and produce dense 3D models. The reconstructed scenes are then acted upon by the 3D feature extractor and the features are compared with pre-trained classifiers from a database to carry out object recognition. The pipeline has been developed to allow for different types of Multi-view Stereo input images. While plane images allow for cheap equipment, spherical and cylindrical panoramic images allow for ease in image acquisition. We have used a modified version of the existent Open Street Map (OSM) Bundler for Structure from Motion and an overlapping view clustering problem for the Multi-view Stereo. Iterative Closest Point algorithm allows for integrating the depth maps to generate the mesh model. The pipeline also allows for an input generated using the Microsoft Xbox Kinect. We have used the Cluster Viewpoint Feature Histogram algorithm (CVFH) for the object recognition and also proposed the use of Normal Aligned Radial Features (NARF). We also study the prospect of using 2D to 3D feature correlation to find objects in the 3D generated model of the room from a 2D image of that room. This work also shows the results of a comparative study undertaken between the different possible methods to complete the task. We also study the different image geometries to further explore the invariance to camera models. Finally the pipeline has been integrated in the Rapid Prototyping Environment (RPE) framework of the Department Interactive Engineering Technologies as a plug-in to provide additional functionality.

BIO Web of Conferences, Vol.1 (2011), 4 p.

One of the research topics within the EU-project SKILLS1 was the training of Industrial Maintenance and Assembly (IMA) tasks. The IMA demonstrator developed comprehends two different training platforms, one based on technologies of Virtual Reality (VR) and the other one on Augmented Reality (AR). To qualify the efficiency of the developed training systems different studies have been conducted, followed by a final "Transfer of Skill" evaluation that has been performed by service technicians "SIDEL industrial training Entre" in Parma. This evaluation included qualitative methods (feedback collection in questionnaires) as well as quantitative methods (experiments with control groups). The results demonstrate that both platforms are useful and suitable training tools for IMA tasks, and that the AR training decreased the number of unsolved errors in the task.

BIO Web of Conferences, Vol.1 (2011), 4 p.

The current work describes design guidelines for the development of Virtual Reality (VR) and Augmented Reality (AR) platforms to train technicians on maintenance and assembly tasks of industrial machineries. The main skill involved in this kind of tasks is the procedural skill. Based on past literature and studies conducted within the SKILLS project, several main design guidelines were formulated. First, observational learning integrated properly within the training protocol increases training efficiency. Second, training protocols combining physical and cognitive fidelity enhances procedural skills acquisition. Third, guidance aids should be provided in a proper and controlled way. And last, enriched information about the task helps trainees to develop a useful mental model of the task. These recommendations were implemented in both VR and AR training platforms.

Increasing complexity of products is a continuing trend, inevitably caused by the strive to create ever better products. This becomes obvious as one imagines sectors like the automotive, aviation and computer hardware industries. As a result processes to change products become increasingly difficult to handle. Therefore the importance of engineering change management (ECM) has grown in manufacturing industries and companies are turning towards software solutions to support them in this task. The work at hand presents an approach to provide software-based support for ECM. It is focused on the support of small and medium-sized businesses, that require a solution that is affordable and yet adapts to their needs. The approach presented in this work meets those requirements with Java-based frameworks and libraries, that provide modularity, configurability and workflow-supported management of ECM processes. Papers dealing with similar topics are examined for potential usefulness and a look at existing commercial solutions is taken to illustrate the industry state-of-the-art. A concept for the core of a system to support ECM processes is designed and subsequently its implementation is described. Finally the results of the thesis are summarized and possible future work is outlined.

Moderne Interaktionsgeräte orientieren sich bei der Interaktion zunehmend an der natürlich menschlichen Interaktion, wie beispielsweise über Gesten. Dieser Trend begann 2006 insbesondere durch den Verkaufserfolg der Spielekonsole Wii von Nintendo und dem dazugehörigen gestenbasierten Controller, der WiiMote. Hierbei war es erstmals möglich Spiele komplett über Gesten zu bedienen. Der Vorteil dieser modernen Interaktion ist die einfachere und leicht verständlichere Kommunikation zwischen und Mensch und Maschine. Im Gegensatz zu solchen proprietären Systemen, die mittels speziell aufeinander abgestimmten Hardware und Software arbeiten, sind im PC Bereich gestenbasierte Steuerungen selten verwendet. Der Grund liegt in einer fehlenden zentralen Unterstützung, so dass Anwendungsentwickler solche Geräte für jede Anwendung individuell berücksichtigen müssen. Dies stellt aber einen großen zusätzlichen Aufwand dar, der selten im Rahmen der Softwareentwicklung berücksichtigt wird. Aus diesem Grund gibt es auch nur wenige Umsetzungen von Anwendungen, die alternative Eingabegeräte unterstützen. Zumeist handelt es sich bei solchen Anwendungen um Spezialsoftware, für deren Zweck die Eingabegeräte und Einbindung der Geräte optimiert sind. Die vorliegende Arbeit sieht daher als Ziel die Entwicklung eines Konzepts für eine zentrale Unterstützung moderner alternativer Eingabegeräte. Hierfür muss zusätzlich eine Klassifikation entwickelt werden, die eine Organisation der verschiedenen Eingabegeräte unter Berücksichtigung der Interaktionsmethoden und benötigtem Interaktionsergebnis (z.B. Koordinaten, erkannte Geste) erlaubt und so eine spätere Einbindung in eine Anwendung vereinfacht und fördert. Mittels dieses Konzepts ist es möglich ein System zu entwickeln, das alle Geräte und deren Interaktionsformen organisiert. Ein Entwickler ist damit in der Lage, unter Verwendung der bereitgestellten Schnittstellen, diese Eingabegeräte in seine Anwendung einzubinden und sie als Kommunikationsmittel für den Nutzer bereitstellen. Zur Entwicklung eines solchen Systems werden zunächst theoretische Ansätze aus dem Bereich der Mensch-Computer-Interaktion betrachtet, die als Grundlage für die methodische Anwendung dienen soll. Dies umfasst auch eine Betrachtung aktuell verfügbarer alternativer Eingabegeräte. Ausgehend von den gewonnenen Erkenntnissen werden insbesondere aktuelle Klassifikationskonzepte, sowie Umsetzungen von Interaktionssystemen betrachtet. Die gesammelten Erkenntnisse werden herangezogen, um ein Konzept für ein Interaktionssystem zu entwickelt und deren zugrundeliegenden Organisation der zu unterstützenden Eingabegeräte. Auf Basis dieses Konzeptes folgt abschließend eine Beschreibung der prototypisch technischen Umsetzung, unter der beispielhaften Verwendung der WiiMote.

Martin, Ralph (Ed.) et al.: The 12th International Conference on Computer-Aided Design and Computer Graphics. Proceedings : CAD / Graphics 2011. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, pp. 3-10

This paper presents a "change'n play" software architecture in order to realize user-centric aspects for, integrated engineering analysis tasks within immersive environments. The proposed architecture has been designed to enable conceptual simulations performed on an engineering mock-up. Major attention is given to the realization of modules and functionalities going far beyond traditional post-processing capabilities, establishing a user centric problem solving environment. It allows closed turnaround simulation-to-visualization loops as well as an inclusion of traditional point-and-click legacy systems, steered from an immersive environment and providing interchangeable mechanism. Existing research work addresses only different aspects, even worse neither does provide a holistic approach nor does show on how to actually do it. Aim of this paper is therefore, to propose and develop an architectural blueprint, supporting "what-if" reasoning with respect to preliminary design analysis objectives: Executed within one single point of access and based on a distributed, hybrid 2D legacy system/VR interactive environment.

Duffy, Vincent G. (Ed.): Digital Human Modeling : Third International Conference: ICDHM 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6777), pp. 282-291

In this paper we present a new framework for an accelerated 3D reconstruction of deformable objects within a multi-view setup. It is based on a new memory management and an enhanced algorithm pipeline of the well known Image-Based Visual Hull (IBVH) algorithm that enables efficient and fast reconstruction results and opens up new perspectives for the scalability of time consuming computations within larger camera environments. As a result, a significant increase of frame rates for the volumetric reconstruction of deformable objects can be achieved using an optimized CUDA-based implementation on NVIDIA's Fermi-GPUs.

Attar, Ramtin (Ed.): 2011 Proceedings of the Symposium on Simulation for Architecture and Urban Design : SimAUD, pp. 135-142

This paper presents a novel vision of paperless and visual lifecycle building management tools based on the coupling between Building Information Models (BIM) and Augmented Reality (AR) called Lifecycle Building Card. As the use of BIM increases within the architecture, engineering, and construction industries, new opportunities emerge to help stakeholders and maintenance operators to leverage the BIM dataset for lifecycle issues using realtime environments and simulation. In particular, a tighter coupling of BIM with computer vision techniques could enable innovative lifecycle management tools based on AR concepts. In this context, this work explores the possibilities and derives theoretical and practical concepts for the use of BIM enhanced by AR for supporting maintenance activities in buildings. An implementation of a wireless spatially-aware display is presented as a first step toward the stated vision.

The American Society of Mechanical Engineers (ASME): ASME 2011 World Conference on Innovative Virtual Reality : WINVR 2011. New York: The American Society of Mechanical Engineers, 2011, 9 p.

This paper presents a new method for the manipulation of a given CAE domain in view of VR based explorations that enables engineers to interactively inspect and analyze a linear static domain. The interactions can ideally be performed in real-time in order to provide an intuitive impression of the changes to the underlying volumetric domain. We take the approach of element masking, i.e. the blending out of computations resulting from computational overhead for inner nodes, based on the inversion of the stiffness matrix. This allows us to optimize the re-simulation loop and to achieve real-time performance for strain and stress distributions with immediate visualization feedback caused by interactively changing boundary conditions. The novelty of the presented approach is a direct coupling of view dependent simulations and its close linkage to post-processing tasks. This allows engineers to also inspect the changes of the stress field inside of the volume during, e.g. cross sectioning.

Stephanidis, Constantine (Ed.): Universal Access in Human-Computer Interaction: Part II : Users Diversity. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6766), pp. 149-158

This paper presents a holistic approach to design a media system based on a new user interface and interaction device aimed to motivate seniors of the generation plus enhancing their daily physical activity. As a result of the newly designed game, the senior finds himself within a colorful world of a game in which he interacts with small lively figures using a newly designed interaction device accounting for physical activity. The combination of both design elements, lead to a gameplay that provides adequate mechanism for cognitive and physical activity, challenging representatives of the generation plus to exercise more.

Keyson, David V. (Ed.) et al.: Ambient Intelligence : Second International Joint Conference, AmI 2011. Berlin; Heidelberg; New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 7040), pp. 314-323

In Ambient Assisted Living (AAL), the context-dependent adaption of a system to a person's needs is of particular interest. In the living area, a fine-grained context may not only contain information about the occupancy of certain furniture, but also the posture of a user on the occupied furniture. This information is useful in the application area of home automation, where, for example, a lying user may effect a different system reaction than a sitting user. In this paper, we present an approach for determining contextual information from furniture, using capacitive proximity sensors. Moreover, we evaluate the performance of Naive Bayes classifiers, decision trees and radial basis function networks, regarding the classification of user postures. Therefore, we use our generic classification framework to visualize, train and evaluate postures with up to two persons on a couch. Based on a data set collected from multiple users, we show that this approach is robust and suitable for real-time classification.

Richard, Paul et al.: Computer Vision, Imaging and Computer Graphics. Theory and Applications : International Joint Conference, VISIGRAPP 2010. Berlin, Heidelberg, New York: Springer, 2011. (Communications in Computer and Information Science 229), pp. 96-109

Segmenting foreground from background automatically is an active field of research. The graph cut approach is one of the promising methods to solve this problem. This approach requires that the weights of the graph are chosen optimally in order to obtain a good segmentation. We address this challenge focusing on the automatic segmentation of wood log images. We present a novel method based on density estimation to obtain information about both foreground and background. With this information the weights in the graph cut method can be set automatically. In order to validate our results, we use four different methods to set these weights. We show that of these approaches, our new method obtains the best results.

Loncaric, Sven (Ed.) et al.: ISPA 2011 : 7th International Symposium on Image and Signal Processing and Analysis. Zagreb: University of Zagreb, 2011, pp. 241-246

Device free communication is getting more and more popular. A comfortable and easy way to accomplish this is interaction with hand gestures. A very good gesture recognition system is required in order to avoid frustration among users. The major challenge in hand gesture recognition lies in an accurate segmentation of the hand. The accurate segmentation of skin colored body parts is an active field of research, and much research has been done to solve this segmentation problem with skin models or skin classification rules. In this paper we address hand segmentation and introduce a novel approach based on the extraction, tracking and verification of skin clusters in color space during runtime. An evaluation shows, that our approach performs significantly better than other approaches used for comparison.

Deformationen von weichem Gewebe während einer Operation sind ein Problem für eine intraoperative Unterstützung durch Rechner. Eine andauernde Veränderung der Form eines Organs erschwert es, eine gute Registrierung zwischen intra- und präoperativen Daten zu finden. Diese Thesis befasst sich mit der Realisierung einer rigiden Registrierung zur Kompensation von Deformation bei verwendeten Leberdaten. Dies wird durch eine Kombination einiger vorgeschlagener Methoden mit einem eigenen Ansatz erreicht, der die Krümmung der Oberfläche mit einbezieht.

This book is a collection of the papers accepted for presentation at the eLBa2011, the 4th International eLearning Baltics Conference held in Rostock, Germany. eLearning Baltics (eLBa) was initiated by representatives from science as well as business. It aims at stimulating and supporting the exchange of new ideas and experiences between research and application, scientists and practitioners. The 4th International eLBa Conference in 2011 focused on eLearning technologies as well as on eLearning didactics and as such addressed a variety of topics from the perspective of computer science, educational science, psychology as well as design. More information about eLearning Baltics is available at http://www.elearning-baltics.eu/

Stephanidis, Constantine (Ed.): Universal Access in Human-Computer Interaction: Part II : Users Diversity. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6766), pp. 32-41

We report on work towards an architecture that incorporates accessible design methods, guidelines and support tools for building and testing adaptive and accessible user interfaces (UI) for users with mild impairments. We especially address interaction constraints for elderly people, both during application design time and at run time, targeting on hybrid TV platforms. The functional principle of our architecture is twofold: At runtime, it lets users interact with hybrid TV applications through an ensemble of accessible UIs that cover different input and output modalities and are jointly adapted via user profiles and real-time feedback. At design time, it allows developers to re-use UIs and representative user personas in simulating the effect of the UI modalities on different impairments.

Verband der Elektrotechnik Elektronik Informationstechnik (VDE): Ambient Assisted Living : 4. Deutscher AAL-Kongress mit Ausstellung. Demographischer Wandel-Assistenzsysteme aus der Forschung in den Markt [CD-ROM]. Berlin u.a.: VDE-Verl., 2011, 9 pp. ; Paper 6.3

Auf Grund von demographischen Entwicklungen hin zu einer alternden Gesellschaft werden AAL-Technologien und Anwendungen eine immer bedeutendere Rolle spielen. Zahlreiche nationale und internationale AAL-Projekte haben überwiegend zu proprietären Lösungen geführt, die nur schwer und mit großem Aufwand miteinander kombinierbar und integrierbar sind. Eine universelle und offene Plattform könnte ein Start für zukünftige Entwicklungen und eine Basis für die Integration standardisierter AAL-Services sein. Das Ziel des universAAL Projektes soll es sein, die Vorteile und Stärken von acht teilweise noch laufenden und abgeschlossenen FP6 und FP7 EU-Projekten zu kombinieren und eine universelle AAL-Plattform zu generieren. Der Fokus liegt dabei auf Interoperabilität und Standardisierung, um die Voraussetzungen zu schaffen, möglichst viele AAL-Anwendungen und Services zu integrieren und es ökonomisch attraktiv zu machen, individuelle AAL-Anwendungen zu generieren. Ziel des Projekts ist auch eine Community zu etablieren, die bereits während der Projektlaufzeit die Projektergebnisse nutzt bzw. eigene Komponenten beiträgt. Ein Software Store und Ressourcen, welche verschiedenste Betriebssysteme unterstützen, werden als Basis Entwicklern als auch Endanwendern bereitgestellt. Eine offene Gesellschaft (AALOA) soll die Interessen an AAL Lösungen verschiedenster Stakeholder zusammenführen und die Community bilden, die offene und standardisierte Komponenten auch über die Projektlaufzeit hinaus unterstützt.

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 4. AAL-Kongress 2011. Berlin: Springer Science+Business Media, 2011. (Advanced Technologies and Societal Change), pp. 127-140

Due to the demographic development towards an ageing society AAL technologies will play an important role in the future. There has been a lot of work done in the field of AAL, but most of the project outcomes are proprietary and thus impossible to be combined. Accordingly, there is a need for an universal and open platform, which can be used as a starting point for further developments or just as an integration and standardization tool. For future service platform related research projects reference use cases as well as a reference tool set and framework would help to ensure a reusable and expandable platform, which is wide spread and therefore ensures a quality of service. The aim of the universAAL project is to combine the advantages and strengths of still ongoing or already finished research projects to create an universally applicable platform. The focus thereby is on interoperability and standardization to ensure a broad range of applicability and to develop an open platform that will make it technically feasible and economically viable to develop AAL applications. There are two tools for spreading the outcomes and ideas of the project planned: On the one hand the establishment of a store providing plug-and-play AAL applications and services that support multiple execution platforms and can be deployed to various devices and users, and on the other hand the AAL Open Association (AALOA) with the mission to create a platform for identifying key research topics in AAL, and to reach agreement on prioritization of these and to design, develop, evaluate and standardize a common service platform for AAL.

Bender, Jan (Ed.) et al.: VRIPHYS 11: 8th Workshop in Virtual Reality Interactions and Physical Simulations. Goslar: Eurographics Association, 2011, pp. 73-82

A natural interaction with virtual environments is one of the key issues for the usability of Virtual Reality applications. Device-free, intuitive interactions with the virtual world can be achieved by capturing the movements of the user with markerless motion capture. In this work we present a markerless motion capture approach which can be used to estimate the human body pose in real-time with a single depth camera. The presented approach requires neither a 3D shape model of the tracked person nor a training phase in which body shapes are learned a priori. Instead, it analyzes the curvature of the human body to estimate the symmetry axes of the body joints. These symmetry axes are then used to calculate the pose of the tracked human in real-time. The presented approach was evaluated qualitatively with a time-of-flight and a Kinect depth camera. Furthermore, quantitative simulation results show that the proposed approach is promising for depth cameras which can reliably capture the surface curvature (and thus the normals) of a person and which have a resolution of at least 320x240 pixel.

In dieser Arbeit wird ein neuer Ansatz im Bereich des markerlosen Motion Capturing vorgestellt, der die Bewegung der Arme, Beine und des Oberkörpers erfasst. Die Erfassung der Bewegung erfolgt dabei in Echtzeit aus den 3D-Messdaten einer Tiefenkamera. Die Tiefendaten sind unvollständig, da die Kamera die Szene nur aus einer Blickrichtung erfassen kann. Der Algorithmus nutzt die zylinderähnliche Form der Arme, Beine und des Oberkörpers aus und berechnet aus den Tiefenbildern die mediale Achse der Körperteile. Für eine effiziente Bestimmung der medialen Achsen werden die räumlichen Nachbarschaftsinformationen der Tiefenbilder ausgenutzt. Die Bewegung wird auf ein virtuelles Skelett abgebildet, indem die Knochen entsprechend der medialen Achsen ausgerichtet werden. Die Bestimmung der Pose erfolgt von Bild zu Bild, so dass eine berechnete Pose als zusätzliche Eingabe für das nächste Bild dient.

Calude, Cristian S. (Ed.) et al.: Rainbow of Computer Science : Dedicated to Hermann Maurer on the Occasion of His 70th Birthday. Berlin, Heidelberg, New York: Springer, 2011, pp. 200-214

A procedural description of a three-dimensional shape has undeniable advantages over conventional descriptions that are all based on the exhaustive enumeration paradigm. Although it is a true generalization, a procedural description of a given shape class is not always easy to obtain. The main problem is that procedural descriptions are typically Turing-complete, which makes 3D shape design formally (and practically) a programming task. We describe an approach that circumvents this problem, is efficient, extensible, and conceptually simple. We demonstrate the broad applicability with a number of examples from different domains and sketch possible future applications. But we also discuss some practical and theoretical limitations of the generative paradigm.

Computers & Education, Vol.57 (2011), 1, pp. 1083-1097

This paper reports on a study, MUSE, which involved Secondary (Grade 7) students in designing and constructing a virtual museum. It presents a description and evaluation of the design and implementation of the technologically-mediated intervention within a language curriculum that emphasizes multimodal meaning-making and expression. Participants' gallery artifacts, interviews, reflections and classroom observations indicated signs of an emergent multimodal awareness with a growing sensitivity to semiotic affordances and constraints. Collaborative learning skills acquired and languages learning motivational gains were evident. The investigation identified responsive, adaptive measures in overcoming unanticipated challenges arising from on-the-ground realities and contextual constraints. The study showed the viability, to a certain extent, of innovative technologically-enhanced interventions in reinforcing instructional pedagogy in classroom contexts.

IEEE Computer Society: XIII Symposium on Virtual Reality : SVR 2011. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, pp. 1-8

Over the years, faster hardware - with higher clock rates - has been the usual way to improve computing times in computer graphics. Aside from highly costly parallel solutions only affordable by big industries - like the movie industry -, there was no alternative available to desktop users. Nevertheless, this scenario is dramatically changing with the introduction of more and more parallelism in current desktop PCs. Multi-core CPUs are a common basis in current PCs and the power of modern GPUs - which have been multi-core for a long time now - is getting unveiled to developers. nVidia's CUDA is a powerful weapon to explore GPUs parallelism. Yet, its specific target - nVidia graphic cards only - does not provide any solution to other parallel hardware present. OpenCL is a new royalty-free cross-platform intended to be portable across different hardware manufacturers or even different platforms. In this paper we focus on a comparison of advantages and disadvantages of xPU platforms with OpenCL and CUDA in terms of time efficiency. As an example application we use ray tracing algorithms. Three kinds of ray tracers have to be developed in order to conduct a fair comparison: one is CPU based, while the other two are GPU based - using CUDA and OpenCL, respectively. At the end, a comparison is done between them and results are presented and analyzed showing that the CUDA implementation has the best frame rate, but is very closely followed by the OpenCL implementation. Visually, results are identical, showing the high potential of OpenCL as an alternative for CUDA with identical performance.

In this paper we present an integrated approach to interactive, real-time targeted multimedia advertisement for digital signage, based on visual audience analysis. Digital Signage and Digital-out-of-Home (DooH) systems nowadays still employ static content scheduling, and only few of them offer basic interaction capabilities, usually based on touch screens. In our approach we use visual sensors attached to a display to measure anonymous properties of the present audience in real-time and to enable touch-less interaction. A combined visual classification scheme analyses facial and full-body image data and integrates results in a long-term observation of individuals. Based on a measured audience profile, considering gender and age, an adaptive media player queries targeted rich media content from a database and presents it to the audience. Content selection is based on an audience state model which considers the spatio-temporal characteristics of the audience (distance, dwell-time) and a content model representing the relations of content and audience. The system automatically offers free-hand gesture interaction to the user, once a certain level of attention is reached. To our knowledge the presented system is the first approach to integrating long-term observation based on facial/full-body visual data, content adaptation and gesture interaction.

Remondino, Fabio (Ed.) et al.: Proceedings of the 4th ISPRS International Workshop 3D-ARCH 2011 : 3D Virtual Reconstruction and Visualization of Complex Architectures [CD-ROM]. (The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XXXVIII-5/W16), 8 p.

Virtual Museums (VM) are a new model of communication that aims at creating a personalized, immersive, and interactive way to enhance our understanding of the world around us. The term "VM" is a short-cut that comprehends various types of digital creations. One of the carriers for the communication of the virtual heritage at future internet level as de-facto standard is browser front-ends presenting the content and assets of museums. A major driving technology for the documentation and presentation of heritage driven media is real-time 3D content, thus imposing new strategies for a web inclusion. 3D content must become a first class web media that can be created, modified, and shared in the same way as text, images, audio and video are handled on the web right now. A new integration model based on a DOM integration into the web browsers? architecture opens up new possibilities for declarative 3D content on the web and paves the way for new application scenarios for the virtual heritage at future internet level. With special regards to the X3DOM project as enabling technology for declarative 3D in HTML, this paper describes application scenarios and analyses its technological requirements for an efficient presentation and manipulation of virtual heritage assets on the web.

Virtual characters offer a great potential as intuitive man-machine interface, because they allow simulating non-verbal communicative behavior as well, which requires the coordinated use of various modalities (e.g., speech and gesture). In this sense, multimodal dialogue systems extend current voice response systems, like for instance known from automated support hotlines, to other modalities. While multimodal dialogue systems are an active research area in artificial intelligence (AI) for over twenty years, in computer graphics (CG) further research is still needed. Hence, in this work two basic problems have been identified. On the one hand, there is a gap between the components of AI and CG, which makes it difficult to provide responsive characters in a manageable manner. On the other hand, embedding virtual agents in full 3D applications, particularly in the context of Mixed Reality, still remains problematic. Therefore, in this work a concept for the presentation component of multimodal dialogue systems has been presented, which can be easily integrated into current frameworks for virtual agents. Basically, it consists of a declarative control layer and a declarative execution layer. While the control layer is mainly used for communication with the AI modules, it also provides a declarative language for describing and flexibly controlling communicative behavior. Core technology components are provided in the execution layer. These include a flexible animation system that is integrated into the X3D standard, components for hair simulation, to represent psycho-physiologically caused skin tone changes such as blushing and the simulation of tears, furthermore methods for the declarative control of the virtual camera, and techniques for the realistic visualization of virtual objects in Mixed Reality scenarios. In addition to simplifying the integration into complex 3D applications, the whole environment can thus also be used by the system as another means of communication.

Shumaker, Randall (Ed.): Virtual and Mixed Reality - Systems and Applications: Part II : International Conference, Virtual and Mixed Reality 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6774), pp. 343-351

In this paper we present a GPU-accelerated implementation of the well-known freeform deformation algorithm to allow for deformable objects within fully interactive virtual environments. We furthermore outline how our real-time deformation approach can be integrated into the X3D standard for more accessibility of the proposed methods. The presented technique can be used to deform complex detailed geometries without pre-processing the mesh by simply generating a lattice around the model. The local deformation is then computed for this lattice instead of the complex geometry, which efficiently can be carried out on the GPU using CUDA.

John, Nigel (Co-Chair) et al.: Eurographics 2011. State of the Art Reports (STARs). Eurographics Association, 2011, pp. 75-100

For many application areas, where a task is most naturally represented by talking or where standard input devices are difficult to use or not available at all, virtual characters can be well suited as an intuitive man-machine-interface due to their inherent ability to simulate verbal as well as nonverbal communicative behavior. This type of interface is made possible with the help of multimodal dialog systems, which extend common speech dialog systems with additional modalities just like in human-human interaction. Multimodal dialog systems consist at least of an auditive and graphical component, and communication is based on speech and nonverbal communication alike. However, employing virtual characters as personal and believable dialog partners in multimodal dialogs entails several challenges, because this requires not only a reliable and consistent motion and dialog behavior but also regarding nonverbal communication and affective components. Besides modeling the "mind" and creating intelligent communication behavior on the encoding side, which is an active field of research in artificial intelligence, the visual representation of a character including its perceivable behavior, from a decoding perspective, such as facial expressions and gestures, belongs to the domain of computer graphics and likewise implicates many open issues concerning natural communication. Therefore, in this report we give a comprehensive overview how to go from communication models to actual animation and rendering.

Virtual Reality, (2011), Online First. Corrected Proof 22 Dezember 2011

Whereas 3D surface models are often used for augmented reality (e.g., for occlusion handling or model based camera tracking), the creation and the use of such dense 3D models in augmented reality applications usually are two separated processes. The 3D surface models are often created in offline preparation steps, which makes it difficult to detect changes and to adapt the 3D model to these changes. This work presents a 3D change detection and model adjustment framework that combines AR techniques with real-time depth imaging to close the loop between dense 3D modeling and augmented reality. The proposed method detects the differences between a scene and a 3D model of the scene in real time. Then, the detected geometric differences are used to update the 3D model, thus bringing AR and 3D modeling closer together. The accuracy of the geometric difference detection depends on the depth measurement accuracy as well as on the accuracy of the intrinsic and extrinsic parameters. To evaluate the influence of these parameters, several experiments were conducted with simulated ground truth data. Furthermore, the evaluation shows the applicability of AR and depth image-based 3D modeling for model-based camera tracking.

BIO Web of Conferences, Vol.1 (2011), 4 p.

The capturing of human movements is an important step for the analysis of human skills, e.g. for sports analysis or for learning-by-demonstration tasks. In this paper we introduce a new markerless pose estimation method which estimates human poses from silhouettes. The presented numerical pose estimation algorithm adapts a non-deterministical annealing schedule for silhouette based motion capturing. The pose is estimated by numerically minimizing the differences between the silhouettes of synthesized views of a 3D avatar and the silhouettes of the real person in the camera images. The evaluation results of simulation experiments quantify the trade-off between the accuracy and the execution time of the presented algorithm.

Jacko, Julie A. (Ed.): Human-Computer Interaction: Part III : Towards Mobile and Intelligent Interaction Environments. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6763), pp. 205-212

The current work is going to provide you information about our solution in the challenge of nutrition and food intake supervision, which has been developed lately. We will give an overview of the system and the implemented mechanisms, which were needed for aiding users in supervising and improving their eating habits. We will show the features, which may be useful for persons who want to analyze their eating habits and try to improve those. Therefore our system provides a cooking advisor, which is able to recognize the available food and respecting those presents the user a list of recipes, which fit his available ingredients and also his nutritional needs. If he wishes, he has also the possibility to set other filter parameters. Additionally the cooked menus are logged by the system and may be subject to further analyses. For determining the available ingredients our system uses RFID technology and also provides the user some community-like features for submitting new receipts or new ingredients.

Wiedmer, Martin (Ed.) et al.: 10th IEEE International Symposium on Mixed and Augmented Reality 2011 : ISMAR. Science & Technology Proceedings, pp. 15-18

With "House of Olbrich" we present an iPhone Augmented Reality (AR) app that visualizes the compelling history of Darmstadt's unique Jugendstil (Art Nouveau) quarter with video-see through Augmented Reality. We propose methods for enabling high performance computer vision algorithms to deploy sophisticated AR visuals on current generation Smartphones by outsourcing resource intensive tasks to the cloud. This allows us to apply methods on 3D feature recognition for even complex tracking situations outdoors, where lightning conditions change and tracked objects are often occluded. By taking a snapshot of the building, the user learns about the architect, design and history of the building. Historical media, like old photographs and blueprints are superimposed on the building's front, depicting the moved history of the famous House of Olbrich, which was destroyed during World War II and has been only rudimentary restored. Augmented Reality technology allows tourists to jump back in time visually by using their Smartphones: Mixing Realities emphasizes the user's experience and leads his attention to the impressive historical architecture of the Art Nouveau. In addition, we ease interaction means by superimposing snapshots. Tourists may view and read information also in a relaxed position without the need to front-up their mobiles all the time.

Wong, Kenneth H. (Ed.) et al.: Medical Imaging 2011: Visualization, Image-Guided Procedures, and Modeling. Part One : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 12, No. 33. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7964), pp. 796416-1 - 796416-8

The purpose of this paper is to present a detailed description of our real-time navigation system for computer assisted surgery. The system was developed with laparoscopic partial nephrectomies as a first application scenario. The main goal of the application is to enable tracking of the tumor position and orientation during a surgery. Our system is based on ultrasound to CT registration and electromagnetic tracking. The basic idea is to process tracking information to generate an augmented reality (AR) visualization of a tumor model in the camera image of a laparoscopic camera. Thereby it enhances the surgeon's view on the current scene and therefore facilitates higher safety during the surgery. So far we have applied our system in vitro during two phantom trials with a surgeon which yielded promising results.

Richard, Paul (Ed.) et al.: GRAPP 2011 : Proceedings of the International Conference on Computer Graphics Theory and Applications. Portugal: SciTePress, 2011, pp. 286-295

Multi-projector systems are widely used in many application areas. Such systems are for instance employed to increase the brightness or the resolution of projected images. Intrinsic to multi-projector systems are problems like geometric misalignment, especially when projecting onto complex arbitrarily formed projection surfaces, and photometric deviations. Therefore, several difficult calibration tasks (geometry, brightness, color) have to be performed. A high-quality and easy-to-use calibration process is the key to good usability for untrained or unexperienced users. Due to the fact that manual calibration is time-consuming and imprecise, automatic approaches were developed in recent years. This paper analyzes the most popular state-of-the-art algorithms and setups with respect to their advantages and disadvantages. We summarize the general working principles of calibration algorithms and provide an outlook into the fields in which the described algorithms are most useful.

Diese Masterarbeit beschäftigt sich mit der Frage, inwieweit sich eine Kameraakquisition für markerloses Motion Capturing in einem Netzwerk mehrerer Rechner verteilen lässt, ohne den eigentliche Prozess der Rekonstruktion zu beeinträchtigen. Hierfür werden vorhandene Algorithmen untersucht und auf eine Client-Server-Architektur verteilt, um so eine ideale Lastverteilung der einzelnen Prozesse zwischen den beteiligten Rechnern zu erzielen. Abschließend wird die Geschwindigkeit der Implementierung untersucht und auf verschiedenen Systemen getestet. Die Schwierigkeit bei einem verteilten System ist einerseits die Synchronisierung aller Komponenten und andererseits die Diskrepanz aus auftretender Datenmenge und im Netzwerk verfügbarer Bandbreite. Zur Synchronisierung wurden Routinen implementiert, die ausschließlich vom Server angestoßen werden können und eine Bestätigung von den Clients erwartet. Dadurch werden sämtliche Clients auf die Geschwindigkeit der schwächsten Komponente gezwungen. Die ebenfalls vom Server ausgehende Triggerung aller Kameras ermöglicht ein synchrones Auslösen. Anhand einer Analyse der auftretenden Bildinformationen wurde zur Datenratenreduktion eine Lauflängenkodierung implementiert, die sowohl einfach umzusetzen als auch schnell in ihrer Berechnung ist. Daraus resultiert eine Trennung der einzelnen Bestandteile mit der Umsetzung von Bayerfilter, Silhouetten-Extraktion, Texturierung und Kodierung auf Seiten der Clients und Dekodierung, Bayerfilter der Texturen und Berechnung der visuellen Hülle auf dem Server. Sämtliche Leistungsanpassungen wurden auf selbst im Konsumentenbereich einfachster Hardware durchgeführt und an die verfügbaren Rechner angepasst. Die Funktionsfähigkeit dieser Umsetzung wurde mit vier Kameras an zwei Clients und acht Kameras an vier Clients getestet und erreichte hierbei eine Geschwindigkeit von durchschnittlich 18 Bildern pro Sekunde.

Brömme, Arslan (Ed.) et al.: BIOSIG 2011 : Proceedings - International Conference of the Biometrics Special Interest Group. Bonn: Köllen, 2011. (GI-Edition - Lecture Notes in Informatics (LNI) P-191), pp. 33-44

The purpose of this paper is to describe the development and performance tests of a contact-free fingerprint sensor, TrueFinger3D (TF3D). This contactless fingerprint sensor is designed to be perfectly interoperable with fingerprint image data captured with contact-based sensors or ink pads. This is achieved by acquiring a 3D dataset of the fingertip together with the image of the papillary lines. Based on the 3D data, the papillary lines image can be processed to compensate perspective foreshortening or even emulate deformation effects caused with contact-based sensors. The 3D measurement mechanism and the image processing are described in detail. The resulting fingerprint images taken by the contactless sensor are then matched with images taken by regular contact-based fingerprint readers at different force levels. The comparison shows that the geometric distortion of our contactless sensor TF3D is comparable to that of contact-based sensors deployed under regular conditions. Our test also shows that contact -based sensors operated under irregular or strong force conditions suffer from a substantial performance degradation, not seen with the contactless sensor TF3D, which has perfect reproducibility. The results also indicate perfect interoperability of the TF3D with any contact-based data and should therefore entitle the sensor to a certification for governmental use.

HafenCity University, Hamburg: GeoViz Hamburg 2011 Workshop : Linking Geovisualization with Spatial Analysis and Modeling [online]. [cited 4 April 2011] Available from: http://www.geomatik-hamburg.de/geoviz/program.html 2011, 2 p.

Cities are under constant development. They are characterized not only by their surface constructions like buildings and traffic infrastructure, but also by their underground structures. Besides human-created lifelines, tunnels and quarries, there are also diverse geological formations. Underground information contains a lot of uncertainty by nature, because measurements provide information along drilling lines only. Additionally, man-made structures are often hardly documented. In this paper we will present ways to visualize such uncertainty in combination with exact surface structures from 3D city models in order to assist stakeholders in making decisions. We will evaluate existing techniques and describe the requirements imposed on uncertainty visualization.

Achieving a high degree of user satisfaction is one main concern when developing eGovernment applications. Only satisfied users will accept the solution as an enrichment of their daily routine and as a valuable alternative to the physical administrative office. The users' attitudes towards an information system can not only be improved by enhancing front-office interfaces or functionalities. Realizing a solution which solves the citizens' problems more quickly and efficiently will have a profound effect as well. The goal of this thesis is to improve eGovernment systems and especially their reaction times by decreasing the time it takes for a citizen's inquiry to reach a responsible official. This will be achieved by developing methods for routing messages according to the user supplied information and additional data for example from geographical information systems or semantically enhanced directory services. The prototype for such a routing or responsibility finding solution will incorporate GIS technologies like WFS and classification algorithms from the field of machine learning and data mining. It is developed in the context of a GeoGovernment application enabling citizens to participate in the improvement of their urban environment - Klarschiff.HRO.

IAPR Newsletter, Vol.33 (2011), 1, pp. 22-25

DAGM is the German section of the IAPR. Every year a conference is held in Germany (or one of the surrounding countries). This year, DAGM took place in Darmstadt. The main conference was preceded by a day at Fraunhofer IGD with a workshop on "Pattern Recognition for IT Security".

Eisert, Peter (Ed.) et al.: VMV 2011 : Vision, Modeling, and Visualization. Goslar: Eurographics Association, 2011, pp. 81-87

Today's super zoom cameras offer a large optical zoom range of over 30x. It is easy to take a wide angle photograph of the scene together with a few zoomed in high resolution crops. Only little work has been done to appropriately display the high resolution photo as an inset. Usually, to hide the resolution transition, alpha blending is used. Visible transition boundaries or ghosting artefacts may result. In this paper we introduce a different, novel approach to overcome these problems. Across the transition, we gradually attenuate the maximum image frequency. We achieve this with a Gaussian blur with an exponentially increasing standard deviation.

Bohn, Christian-Arved (Ed.) et al.: Virtuelle und Erweiterte Realität : 8. Workshop der GI-Fachgruppe VR/AR. Aachen: Shaker, 2011. (Berichte aus der Informatik), 9 p.

We address artifacts at corners in soft edge blend masks for tiled projector arrays. We compare existing and novel modifications of the commonly used weighting function and analyze the first order discontinuities of the resulting blend masks. In practice, e.g. when the projector lamps are not equally bright or with rear projection screens, these discontinuities may lead to visible artifacts. By using first order continuous weighting functions, we achieve significantly smoother results compared to commonly used blend masks.

Computer Graphics Forum, Vol.30 (2011), 6, pp. 1719-1749

The analysis of large graphs plays a prominent role in various fields of research and is relevant in many important application areas. Effective visual analysis of graphs requires appropriate visual presentations in combination with respective user interaction facilities and algorithmic graph analysis methods. How to design appropriate graph analysis systems depends on many factors, including the type of graph describing the data, the analytical task at hand and the applicability of graph analysis methods. The most recent surveys of graph visualization and navigation techniques cover techniques that had been introduced until 2000 or concentrate only on graph layouts published until 2002. Recently, new techniques have been developed covering a broader range of graph types, such as timevarying graphs. Also, in accordance with ever growing amounts of graph-structured data becoming available, the inclusion of algorithmic graph analysis and interaction techniques becomes increasingly important. In this State-of-the-Art Report, we survey available techniques for the visual analysis of large graphs. Our review first considers graph visualization techniques according to the type of graphs supported. The visualization techniques form the basis for the presentation of interaction approaches suitable for visual graph exploration. As an important component of visual graph analysis, we discuss various graph algorithmic aspects useful for the different stages of the visual graph analysis process. We also present main open research challenges in this field.

IEEE/ACM Transactions on Computational Biology and Bioinformatics, Vol.8 (2011), 6, pp. 1678-1684

Scanning protein sequence database is an often repeated task in computational biology and bioinformatics. However, scanning large protein databases, such as GenBank, with popular tools such as BLASTP requires long runtimes on sequential architectures. Due to the continuing rapid growth of sequence databases, there is a high demand to accelerate this task. In this paper, we demonstrate how GPUs, powered by the Compute Unified Device Architecture (CUDA), can be used as an efficient computational platform to accelerate the BLASTP algorithm. In order to exploit the GPU's capabilities for accelerating BLASTP, we have used a compressed deterministic finite state automaton for hit detection as well as a hybrid parallelization scheme. Our implementation achieves speedups up to 10.0 on an NVIDIA GeForce GTX 295 GPU compared to the sequential NCBI BLASTP 2.2.22. CUDA-BLASTP source code which is available at https://sites.google.com/site/liuweiguohome/software.

Diese Arbeit stellt ein neuartiges Konzept für ein mobiles Sturzerkennungssystem vor. Basierend auf den Daten eines Beschleunigungssensors und des Mikrofons sollen Stürze erkannt werden. Zu diesem Zweck werden Versuchsdaten ausgewertet und Merkmale extrahiert, die eine Sturzerkennung erlauben. Anschließend wird das entwickelte Konzept als Prototyp für ein Smartphone umgesetzt. Das verwendete Smartphone Sony Ericsson Xperia X10 besitzt einen integrierten Beschleunigungs-sensor und ein Mikrofon. Eine Anforderungsanalyse soll zeigen, dass das Smartphone zur mobilen Sturzerkennung geeignet ist. Im weiteren Verlauf der Arbeit wird eine Serveranwendung vorgestellt, die bei einem vom mobilen Sturzerkennungssystem gemeldeten Sturz, von einer Notfallzentrale genutzt werden kann. Weiterhin soll eine Evaluation des mobilen Sturzerkennungssystems zeigen, wie gut der Prototyp Stürze erkennt und wie viele Fehlerkennungen von Stürzen auftreten. Zum Abschluss der Arbeit werden Erweiterungen des mobilen Sturzerkennungssystems vorgestellt, welche die Erkennungsrate verbessern und die Serveranwendung erweitern können.

Eisert, Peter (Ed.) et al.: VMV 2011 : Vision, Modeling, and Visualization. Goslar: Eurographics Association, 2011, pp. 161-168

Usually, terrain rendering relies on a 2D regular grid of height values, the so called height field. Height fields describe 2.5D surfaces and are not able to present complex 3D terrain features. In contrast, a 3D data representation quickly exceeds the available memory resources. To overcome this problem we apply material stacks. Material stacks combine the simplicity of 2D height fields and the extended modelling capabilities of 3D volumetric data. However, this approach requires expensive rendering and is difficult to realize in real-time. In this paper we present an innovative real-time rendering approach of terrains relying on material stacks. Our approach is based on two major steps: First, a LoD hierarchy for material-stacks is generated. Second, during rendering a multi-staged quadrangulation pipeline extracts terrain surface from the material stacks. As a result, we achieve real-time frame rates at high resolutions.

Wong, Pak Chung (Ed.) et al.: Visualization and Data Analysis 2011. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7868), pp. 786808-1 - 786808-8

The reconstruction of a continuous function from discrete data is a basic task in many applications such as the visualization of 3D volumetric data sets. We use a local approximation method for quadratic C1 splines on uniform tetrahedral partitions to achieve a globally smooth function. The spline is based on a truncated octahedral partition of the volumetric domain, where each truncated octahedron is further split into a fixed number of disjunct tetrahedra. The Bernstein-Bézier coefficients of the piecewise polynomials are directly determined by appropriate combinations of the data values in a local neighborhood. As previously shown, the splines provide an approximation order two for smooth functions as well as their derivatives. We present the first visualizations using these splines and show that they are well-suited for GPU-based, interactive high-quality visualization of isosurfaces from discrete data.

Smith, Michael J. (Ed.) et al.: Human Interface and the Management of Information: Part I : Interacting with Information. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6771), pp. 567-576

Ambient Assisted Living (AAL) comprises methods, systems, and services applied to improve the quality of daily life for humans, especially elderly people. Recent research emphasizes the implementation of comprehensive AAL platforms which control all technological components included in the entire environment such as one's apartment. The behavior of the system is often determined by a specific set of rules. Thus, personalization according to the person's needs and preferences includes a configuration of the given rule system. Assuming that configuration is not only conducted by technical staff but also by the person him or herself, this process can be regarded as complex, requiring technical knowledge. In this work, we present an interactive and architectural approach to support at the personalization of an AAL system by different types of users.

Miksch, Silvia (Ed.) et al.: IEEE Conference on Visual Analytics Science and Technology 2011. Proceedings : VAST 2011. New York: IEEE Press, 2011, pp. 111-120

We propose a method for the semi-automated refinement of the results of feature subset selection algorithms. Feature subset selection is a preliminary step in data analysis which identifies the most useful subset of features (columns) in a data table. So-called filter techniques use statistical ranking measures for the correlation of features. Usually a measure is applied to all entities (rows) of a data table. However, the differing contributions of subsets of data entities are masked by statistical aggregation. Feature and entity subset selection are, thus, highly interdependent. Due to the difficulty in visualizing a high-dimensional data table, most feature subset selection algorithms are applied as a black box at the outset of an analysis. Our visualization technique, SmartStripes, allows users to step into the feature subset selection process. It enables the investigation of dependencies and interdependencies between different feature and entity subsets. A user may even choose to control the iterations manually, taking into account the ranking measures, the contributions of different entity subsets, as well as the semantics of the features.

Miksch, Silvia (Ed.) et al.: EuroVA 2011 : International Workshop on Visual Analytics. Goslar: Eurographics Association, 2011, pp. 13-16

We propose a visualization method for the diagnosis and interactive refinement of automatic techniques for feature subset selection. So-called filter techniques use statistical ranking measures to identify the most useful combination of features for further analysis. Usually a measure is applied to all entities of a data-table. The influence of atypical entities can distort the result, but this distortion may be masked by the statistical aggregation. Clearly, feature and entity subset selection are highly interdependent. Our technique, SmartStripes, intends to make this interdependency visible.

Bertram, Volker (Ed.): COMPIT' 11 : 10th International Conference on Computer and IT Applications in the Maritime Industries. Technische Universität Hamburg-Harburg, 2011, pp. 326-334

Safety is considered as one of the key issues in ship design and operation, especially for passenger vessels. This motivates research applying advanced computer graphics technology for ship safety analysis. We have implemented a scenario allowing the evaluation of evacuation simulation results carried out for passenger vessels in a virtual reality (VR) environment. By combining available 2D simulation data with the 3D data of the ship, additional insights with respect to critical points such as stairways and narrow passage ways can be gained, which opens up the opportunity to early design improvements. One of the major technical challenges solved in this context, is the real time visualization of the fully outfitted ship. When reviewing the simulation within the virtual environment, the evaluator can navigate intuitively, using 2D-deck plans on a multi-touch device.

Bei der Simulation von elastischen Deformationen mit Hilfe der Finiten-Elemente-Methode gibt es zwei Möglichkeiten die Genauigkeit der Approximation zu verbessern. Zum Einen die Erhöhung der Anzahl der Elemente, zum Anderen die Erhöhung des Polynomgrades der Basisfunktionen. Durch die Erhöhung des Polynomgrades steigt die Anzahl der Freiheitsgrade, was wiederum zu längeren Berechnungszeiten führt. Beschrieben wird die elastische Deformation von Körpern durch Partielle Differentialgleichungen (PDGLn) mit glatten Lösungen. Dies ermöglicht die Approximation der PDGLn mit den Basisfunktionen von Splines, die weniger Freiheitsgrade benötigen, da sie wegen ihrer Stetigkeitseigenschaften per Definition glatte Funktionen beschreiben. Die Simulation deformierbarer Materialien mit Splinefunktionen wird vorgestellt und die dadurch erreichte Genauigkeit und Performanz wird ermittelt und im Vergleich zur Finiten-Elemente-Methode diskutiert.

Kramme, Rüdiger (Ed.): Medizintechnik : Verfahren - Systeme - Informationsverarbeitung. Berlin, Heidelberg, New York: Springer, 2011, pp. 847-858

Die rasanten Entwicklungen, die sich in den letzten 20 Jahren vollzogen haben, haben die Chirurgie maßgeblich verändert, und sie wird unvermeidlich noch größere Änderungen in den nächsten Jahren erfahren. Die Chirurgie wird zunehmend technologiebasiert. In der Computergraphik bilden Techniken der virtuellen Realitat (VR) eine neue Dimension in der Mensch-Maschine-Interaktion. In der Chirurgie hat ein Wechsel des Interaktionsparadigmas durch den Übergang von der offenen zur minimalinvasiven Chirurgie (MIC) stattgefunden.

Kramme, Rüdiger (Ed.) et al.: Springer Handbook of Medical Technology. Berlin, Heidelberg, New York: Springer, 2011, pp. 1167-1186

Medicine over the past decades has undergone significant changes. In particular, surgery has become increasingly more technology based due to advances and rapid developments in device technology and computer graphics. Minimally invasive surgery (MIS) has revolutionized surgery introducing optical systems and small surgical instruments. In computer graphics Virtual Reality (VR) allows a more intuitive interaction with three-dimensional (3-D) computer generated environments. Furthermore, Augmented Reality (AR) provides a real-time overlay of reality with digital information. This transformation opens up new opportunities for diagnostics, medical education, preoperative planning and intraoperative support. The traditional see one, do one, teach one educational environment has now changed to simulation-based training where sophisticated surgical procedures can be planned and rehearsed in a safe virtual environment before the patient enters the operating room (OR). In the operating theatre the surgeon's abilities can be enhanced by superimposing computer generated information on the real patient resulting in better navigation and higher precision of the surgical intervention. With the increasing role of quality management and certification in the health care system, medical simulation can lead to improved quality of care and patient outcomes becoming an integral element finally.

Smith, Michael J. (Ed.) et al.: Human Interface and the Management of Information: Part I : Interacting with Information. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6771), pp. 239-248

Semantically annotated data gain more and more importance in future information acquiring processes. Especially the Linked Open Data (LOD) format has already experienced a great growth. However, the user-interfaces of web-applications mostly do not reflect the added value of semantics data. The following paper describes a new approach of user-centered data-adaptive semantics visualization, which makes use of the advantages of semantics data combined with an adaptive composition of information visualization techniques. It starts with a related work section, where existing LOD systems and information visualization techniques are described. After that, the new approach will bridge the gap between semantically annotated data (LOD) and information visualization and introduces a visualization system that adapts the composition of visualizations based on the underlying data structure. A case study of an example case will conclude this paper.

Kurosu, Masaaki (Ed.): Human Centered Design : Second International Conference: HCD 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6776), pp. 576-585

Presenting information in a user-oriented way has a significant impact on the success and comprehensibility of data visualizations. In order to correctly and comprehensibly visualize data in a user-oriented way data specific aspects have to be considered. Furthermore, user-oriented perception characteristics are decisive for the fast and proper interpretation of the visualized data. In this paper we present a taxonomy for graph visualization techniques. On the one hand it provides the user-oriented identification of applicable visual features for given data to be visualized. On the other hand the set of visualization techniques is enclosed which supports these identified visual features. Thus, the taxonomy supports the development of user-oriented visualizations by examination of data to obtain a beneficial association of data to visual features.

Stephanidis, Constantine (Ed.): Universal Access in Human-Computer Interaction: Part II : Users Diversity. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6766), pp. 88-97

The automatic adaptation of information visualization systems to the requirements of users plays a key-role in today's research. Different approaches from both disciplines try to face this phenomenon. The modeling of user is an essential part of a user-centered adaptation of visualization. In this paper we introduce a new approach for modeling users especially for semantic visualization systems. The approach consists of a three dimensional model, where semantic data, user and visualization are set in relation in different abstraction layer.

Kurosu, Masaaki (Ed.): Human Centered Design : Second International Conference: HCD 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6776), pp. 566-575

Today the information visualization takes in an important position, because it is required in nearly every context where large databases have to be visualized. For this challenge new approaches are needed to allow the user an adequate access to these data. Static visualizations are only able to show the data without any support to the users, which is the reason for the accomplished researches to adaptive user-interfaces, in particular for adaptive visualizations. By these approaches the visualizations were adapted to the users' behavior, so that graphical primitives were change to support a user e.g. by highlighting user-specific entities, which seems relevant for a user. This approach is commonly used, but it is limited on changes for just a single visualization. Modern heterogeneous data providing different kinds of aspects, which modern visualizations try to regard, but therefore a user often needs more than a single visualization for making an information retrieval. In this paper we describe a concept for adapting the user-interface by selecting visualizations in dependence to automatically generated data characteristics. So visualizations will be chosen, which are fitting well to the generated characteristics. Finally the user gets an aquatically arranged set of visualizations as initial point of his interaction through the data.

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 4. AAL-Kongress 2011. Berlin: Springer Science+Business Media, 2011. (Advanced Technologies and Societal Change), pp. 75-90

Using modern interaction methods and devices provides a more natural and intuitive interaction. Currently, only mobile phones and game consoles which are supporting such gesture-based interactions have good payment-rates. This comes along, that such devices will bought not only by the traditional technical experienced consumers. The interaction with such devices becomes so easy, that also older people playing or working with them. Especially older people have more handicaps, so for them it is hard to read small text, like they are used as description to buttons on remote controls for televisions. They also become fast overstrained, so that bigger technical systems are no help for them. If it is possible to interact with gestures, all these problems can be avoided. But to allow an intuitive and easy gesture interaction, gestures have to be supported, which are easy to understand. Because of that fact, in this paper we tried to identify intuitive gestures for common interaction scenarios on computer-based systems for uses in ambient assisted environment. In this evaluation, the users should commit their opinion of intuitive gestures for different presented scenarios/tasks. Basing on these results, intuitively useable systems can be developed, so that users are able to communicate with technical systems on more intuitive level with accelerometer-based devices.

Jacko, Julie A. (Ed.): Human-Computer Interaction: Part I : Design and Development Approaches. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6761), pp. 480-489

One key issue of both Information Visualization as well as Adaptive User Interfaces is information overload. While both disciplines have already devised well performing algorithms, methods and applications, a real merging has not taken place yet. Only a few attempts bring the surplus values of both disciplines together, whereas a fine-grained investigation of visualization parameterization is not investigated. Today's systems focus either on the adaptation of visualization types or the parameterization of visualizations. This paper presents a reference Model for Adaptive Visualization Systems (MAVS) that allows the adaptation of both the visualization type and the visualization parameterization. Based on this model, a framework for the adaptive visualization of semantics data will be derived. A use case describing the interaction with an "adaptive visualization cockpit" covering different visualization metaphors concludes the paper.

Verband der Elektrotechnik Elektronik Informationstechnik (VDE): Ambient Assisted Living : 4. Deutscher AAL-Kongress mit Ausstellung. Demographischer Wandel-Assistenzsysteme aus der Forschung in den Markt [CD-ROM]. Berlin u.a.: VDE-Verl., 2011, 7 pp. ; Paper 6.4

Durch den demographischen Wandel bedingt, bieten Wohnen und Pflege in der gewohnten häuslichen Umgebung für einen immer größer werdenden Anteil der Bevölkerung eine attraktivere Alternative zur stationären Unterbringung. Trotz des großen zukünftigen Marktpotenzials für einschlägige Unternehmen steht die AAL-Branche jedoch noch nicht vor dem Durchbruch. Als größtes Markthemmnis für einen breiten Einsatz innovativer Assistenzsysteme werden nahezu übereinstimmend fehlende Geschäftsmodelle genannt. Dieser Beitrag beleuchtet, wo Gründe hierfür liegen können und zeigt auf, warum die AAL-Community nicht um Gesamtlösungen auf Basis einer einheitlichen AAL-Referenzplattform herumkommt. Er beschreibt aber auch das enorme Potenzial von AmI und AAL, das durch universAAL und AALOA erstmals eine wirkliche Chance erhält.

Bei der Planung von Leberoperationen ist es hilfreich, den Verlauf der Portal- sowie der Lebervene zu kennen, um bestimmte Lebersegmente sowie verschiedene Typen von Tumoren identifizieren zu können. Auch wenn die beiden Venen in der Realität vollständig voneinander getrennt sind, kommt es aufgrund der niedrigen optischen Auflösung, mit der CT-Daten gewonnen werden, in den segmentierten Volumendaten der beiden Venen zu Verschmelzungen. Diese Bachelorarbeit beschreibt ein eigenes, neues Verfahren zur Identifizierung dieser Verbindungsstellen innerhalb einer Graphenrepräsention der Portal- und der Lebervene. Nach einer Erläuterung benötigter Grundlagen folgt eine zusammenfassende Beschreibung bereits existierender Trennungsalgorithmen. Auf diesen aufbauend wird die Idee des neuen Verfahrens formuliert, das die Festlegung auf eine Trennungsstelle von dem häufigsten Zusammentreffen derjenigen Kriterien abhängig macht, die für die Trennung an dieser Stelle sprechen. Anschließend wird der neue Trennungsalgorithmus ausführlich beschrieben. Da der Algorithmus die als Wurzeln bezeichneten Eingänge in das Gefäßsystem kennen muss, wird für die Detektion der Wurzeln die Modifizierung eines bestehenden Verfahrens sowie ein weiteres, eigenes Verfahren vorgestellt. Auf Möglichkeiten zur Identifizierung von Zyklen in Graphen sowie zur Suche von wurzelverbindenden Kantenpfaden wird ebenfalls eingegangen, da diese zur Implementierung des Trennungsalgorithmus bekannt sein müssen. Abschließend werden die Ergebnisse vorgestellt, die das Trennungsverfahren bei Testdatensätzen lieferte. Hierbei wurden für 21 Verbindungsstellen 17 Trennungsvorschläge korrekt generiert.

Wiedmer, Martin (Ed.) et al.: 10th IEEE International Symposium on Mixed and Augmented Reality 2011. [USB Stick] : ISMAR. Science & Technology Proceedings, pp. 269-270

As large ships are never produced in masses, it often occurs that the construction process and production process overlap in time. Many shipbuilding companies have problems with discrepancies between the construction data and the real built ship. The assembly department often has to modify CAD data for a successful installation. We present an augmented reality system, where a user can visualize the construction data of pipes and modify these in the case of misalignment, collisions or any other conflicts. The modified pipe geometry can be stored and further used as input for CNC pipe bending machines. To guarantee an exactly orthogonal passage of the pipes through aligning bolt holes, we integrated an optical measurement tool into the pipe alignment process.

Keyson, David V. (Ed.) et al.: Ambient Intelligence : Second International Joint Conference, AmI 2011. Berlin; Heidelberg; New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 7040), pp. 264-274

In the Ambient Assisted Living (AAL) domain, specific systems have been developed and applied to enable people with specific needs, such as elderly or disabled people, to live longer independently in their familiar residential environments. In order to support the development of such systems, a range of AAL platforms have been developed in recent years. However, there are considerable differences among these AAL platforms, particularly with respect to the treatment of important non-functional properties. This makes the selection of a suitable platform for a given AAL project very difficult. In order to support developers in this difficult task, we present an evaluation of relevant AAL platforms based on a selection of quality attributes that are important for AAL systems.

Computers & Graphics, Vol.35 (2011), 2, pp. 299-311

Many inexact automatic tree matching algorithms are available. However, they provide matches that are not completely error free. Another option is to use manually matched node-pairs, but this enormously slows down the process. Our contribution to the state of the art is to combine the advantages of both solutions. We enhance the automatic tree matching algorithm designed by Graham et al., so that it is possible to interact with it by previously selecting important matches or by subsequently fixing the provided wrong matches. We apply the tree matching algorithm to the anatomical vasculature of the liver. Furthermore, we developed several visualization features to make manual tree interaction as easy as possible. Both, the interactive and automatic part of the implemented component were evaluated. As a result, the speed of the automatic tree matching algorithm is increased. It takes 7.45 s for trees up to 192 nodes and less than 1 s if three input matches are provided. In addition to this, an in-depth evaluation of the robustness of the algorithm is presented. The results are remarkable. The average of wrong matches varies between 1.17 and 1.4 node-pairs in the worst cases. The rate of correct matches is high. The evaluation of the visualization features for interactive refinement of matches showed that the percentage of wrong matches found is increased from 56.25% to 78.43%. The mean time to find them is decreased from 227 to 122 s.

Solomonides, Tony (Ed.): Twenty-Fourth IEEE Symposium on Computer-Based Medical Systems and HealthGrid Conference : CBMS 2011 + HG 2011. Los Alamitos, Calif.: IEEE Computer Society, 2011, 6 p.

State of the art anatomical tree matching algorithms find correspondences between trees that contain topological differences. However there are still open problems that were not considered until now. For example, when the liver vasculature is segmented, portal and hepatic vein are not separated due to segmentation errors. Because of this reason the resulting structure is not a tree but a graph. On the other hand, inaccuracies in the generation of the graph, as well as artifacts or inhomogeneities in the contrast medium result in graphs containing gaps. In this work, we present a novel graph to graph matching algorithm. It solves the aforementioned problems by taking the whole graph structure into account and does not depend on separated trees. In addition to this it is robust against gaps in the graph. We developed our algorithm so that it does not depend on the root of the graph which is often assumed to be known. The algorithm was evaluated on real clinical data of the liver.

Diese Bachelorarbeit behandelt die Erkennung wiederkehrender Strukturelemente in entzerrten Fassadenaufnahmen. Dem Überblick über die Grundlagen der Strukturerkennung folgt die Erläuterung zur Konzeption und Umsetzung des Systems zur Strukturerkennung. Dabei greift das System hauptsächlich auf Erkenntnisse der Symmetrieerkennung zurück, um Strukturen erkennen zu können. Weiterhin werden Überleitungen zur Regelmäßigkeitserkennungen gebildet. Abschließend werden Testresultate vorgestellt und es wird gezeigt, dass Symmetrieerkennung ein Grundstein zur Strukturerkennung sind kann.

Die 3D-Koordinaten von Punkten auf einer Objektoberfläche können entweder mit einer Tiefenkamera gemessen oder durch Structure-from-Motion Verfahren aus mehreren 2D Bildern rekonstruiert werden. In dieser Arbeit wird vergleichend evaluiert, welche Genauigkeit mit diesen beiden Verfahren erreicht werden kann. Für eine aussagekräftige Evaluierung muss die Kamerapose zur Berechnung der (echten) 3D-Referenzdaten bekannt sein. Während in vorhergehenden Ansätzen die Kamerapose bildbasiert (z.B. anhand eines Marker Trackers) geschätzt wurde, wird die Kamerapose in dieser Arbeit anhand eines hochpräzisen Faro-Messarms bestimmt. Hierdurch wird eine höhere Genauigkeit erreicht als bei Bestimmung der Kamerapose anhand eines Marker Trackers, was die Aussagekraft der Evalierungsergebnisse erhöht.

Alem, Leila (Ed.) et al.: Recent Trends of Mobile Collaborative Augmented Reality Systems. Berlin, Heidelberg, New York: Springer, 2011, pp. 21-38

This chapter discusses the current state, issues, and direction of the development and use of international standards for use in Augmented Reality (AR) applications and services. More specifically, the paper focuses on AR and mobile devices. Enterprise AR applications are not discussed in this chapter. There are many existing international standards that can be used in AR applications but there may not be defined best practices or profiles of those standards that effectively meet AR development requirements. This chapter provides information on a number of standards that can be used for AR applications but may need further international agreements on best practice use.

Dellepiane, Matteo (Ed.) et al.: VAST 2011 : Eurographics Symposium Proceedings. Goslar: Eurographics Association, 2011, pp. 89-96

The digitally documented world heritage is archived in databases or repositories, where collections of metadata, images, multimedia objects or nowadays even digital 3D artifacts can be stored and queried. Modeling and linking all this information is complex and involves refined categorizations and relations, which are usually accessed by either simplistic or overwhelmingly complex interfaces. Hence, finding the right level of abstraction for a general interface is very challenging. This becomes even more demanding, if in addition to collection exploration, semantic enrichment is required. This work focuses on the design and implementation of an integrated interface, in which four dedicated activities are combined and provided: i) flexible definition of relational queries, ii) browsing of multiple results and query refinement, iii) inspection and analysis of multimedia objects, and iv) building and enrichment of semantic relationships (data paths) between objects. This integrated interface can handle different kinds of multimedia objects, allowing for querying and annotating text, 2D images or 3D artifacts. We present the software design of this interface and the corresponding underlying model in the semantic network. This work is a general step toward interfacing to 3D Linked Open Data.

International Association for the Engineering Analysis Community (NAFEMS): A World of Engineering Simulation: Industrial Needs, Best Practice, Visions for the Future : NWC 2011. NAFEMS World Congress [Book of Abstracts & CD-ROM]. Glasgow: NAFEMS, 2011, 18 p.

The digital exploration of design variations is a key procedure in the embodiment phase of engineering design, in order to efficiently develop optimal solutions. This procedure requires the combination of modeling and simulation capabilities, enabling the engineer to assess the physical and functional behaviors of the proposed solution. Nowadays, this procedure is performed by means of iterating between designers and analysts with their corresponding tools and demanding reciprocal understanding between them. This is nonetheless a very time consuming activity with the currently available tools and technology, even the advance Computer Aided Design (CAD) systems, which can cope with almost any modeling requirement and which presently provide direct connection (i.e. meshing) to analysis modules for models with limited complexity, cannot deal with the interactive exploration of design variations. Moreover, the promising isogeometric analysis, which aims to simulate 3D NURBS representations also requires special transformations (i.e. meshing), which do not allow for interactive exploration of design variations. On the other side, the Computer Aided Engineering (CAE) systems offering morphing support, are only able to explore restricted variations, since large variations or deformations of the model involves expensive remeshing processes. In order to overcome the above mentioned issues and to enable a fully interactive exploration of design variations within an analysis environment, we enhance the simulating model with a high level representation for interacting with semantic features rather than with single elements, we perform combined morphing techniques with local mesh modification for preserving the stability of the numerical model during large variations, and we decouple the storage of the linear system entries and the sequential matrixvector multiplication for getting the solution, in order to permit the update of local entries of the matrix representing the local mesh modifications without the need of a rebuild of the entire system. Our methodology allows the engineers to independently and interactively explore conceptual design variations without restrictions. Hence, the investigation and understanding of the influence of different design features can easily and fast be evaluated and the development of optimal solutions for the design requirements can closely be fulfilled.

Larsson, Thomas (Ed.) et al.: SIGRAD 2011 : Evaluations of Graphics and Visualization - Efficiency, Usefullness, Accesibility, Usability. Linköping: Linköping University Electronic Press, 2011. (Linköping Electronic Conference Proceedings 65), pp. 83-90

The use of 3D shapes in different domains such as in engineering, entertainment, cultural heritage or medicine, is essential for representing 3D physical reality. Regardless of whether the 3D shapes are representing physically or digitally born objects, meshes are a versatile and common representation for the 3D reality. Nonetheless, the mesh generation process does not always produce qualitative results, thus incomplete, non-orientable or non-manifold meshes frequently are the input for the domain application. The domain application itself also demands special requirements, e.g. an engineering simulation requires a volumetric mesh either tetrahedral or hexahedral, while a cultural heritage color enhancement uses a triangular or quadrangular mesh, or in both cases even hybrid meshes. Moreover, the processes applied on the meshes (e.g. modeling, simulation, visualization) need to support some operations, such as querying neighboring information or enabling dynamic changes of geometry and topology. These operations need to be robust, hence the neighboring information can be consistently updated, during the dynamic changes. Dealing with this mesh diversity usually requires dedicated data structures for performing in the given domain application. This paper compiles the considerations toward designing a data structure for dynamic meshes in a generic and robust manner, despite the type and the quality of the input mesh. These aspects enable a flexible representation of 3D shapes toward general purpose geometry processing for dynamic meshes in 2D and 3D.

Interacting with Computers, Vol.23 (2011), 4, pp. 372-383

Affective responses of users to system messages in human-computer interaction are a key to study user satisfaction. However, little is known about the particular affective patterns elicited by various types of system messages. In this experimental study we examined if and how different system messages, presented in different modalities, influence users' affective responses. Three types of messages, input requests, status notifications, and error messages, were presented either as text or speech, and either alone or in combination with icons or sounds, while users worked on several typical computer tasks. Affective responses following system messages were assessed employing a multi-modal approach, using subjective rating scales as well as physiological measures. Results show that affective responses vary systematically depending on the type of message, and that spoken messages generally elicit more positive affect than written messages. Implications on how to enhance user satisfaction by appropriate message design are discussed.

Arabnia, Hamid R. (Ed.) et al.: Software Tools and Algorithms for Biological Systems. Berlin, Heidelberg, New York: Springer, 2011. (Advances in Experimental Medicine and Biology 696), pp. 367-375

Early prediction of cancer reoccurrence constitutes a challenge for oncologists and surgeons. This paper describes one ongoing experience, the EU-Project NeoMark, where scientists from different medical and biology research fields joined efforts with Information Technology experts to identify methods and algorithms able to early predict the reoccurrence risk for one of the most devastating tumors, the Oral cavity Squamous Cell Carcinoma (OSCC). The challenge of NeoMark is to develop algorithms able to identify a "signature" or bio-profile of the disease, by integrating multiscale and multivariate data from medical images, genomic profile from tissue and circulating cells RNA and other medical parameters collected from patients before and after treatment. A limited number of relevant biomarkers will be identified and used in a real-time PCR device, for early detection of disease reoccurrence.

Diese Arbeit beschreibt den aktuellen Forschungsstand und derzeitige Anwendungsbeispiele bei der Bewertung von Inhalten, Autoren und Bewertungen in Communities. Bewertungsmöglichkeiten, die in verschiedenen Communities eingesetzt werden, sowie die Gewichtung der Beiträge von Mitgliedern und Experten, werden beleuchtet. Hierzu werden Communities im World Wide Web identifiziert und auf ihre Bewertungsmöglichkeiten, Profildatenspeicherung und divergierende Besonderheiten untersucht. Bei der Gewichtung der Beiträge wurden die Benutzereigenschaften von Mitgliedern und Experten differenziert betrachtet.

In a face or facial expression recognition system, one of the key requirements is the proper generation of a face model. An approach for reconstructing the 3D face model from a video sequence is presented within this thesis. A generic deformable 3D face model is built from the 3D scans of one hundred individuals. This generic 3D face model allows modelling the variation in the face-shape of different people. It can be fitted to the reconstructed 3D face-shape of an individual from a video sequence provided that the deviation from the real 3D face is less than certain thresholds. The methodology for reconstructing the 3D face-shape from a video sequence is provided. A structure-from-motion technique is used to estimate the poses of images in a video sequence. The estimated poses are optimized further by applying a bundle adjustment technique. Finally the dense correspondences between the images are estimated by employing Huber-L1 optical flow algorithm. With the optimized pose parameters and dense correspondences between the images, dense 3D face-shapes are reconstructed from a video sequence. The application is developed to reconstruct the 3D face-shape in nearly uncontrolled environment where challenges exists due to varying lightning conditions, the non steady camera movement while capturing a video sequence and other factors using most promising state-of-the-art algorithm. Given the nearly uncontrolled conditions we were able to estimate a point cloud representing the face shape, but the results are not as accurate as expected. The related state-of-the-art algorithms used here have not been considered for such challenging conditions. The factors affecting the depth estimation in face region are analyzed and possible improvements to enhance the 3D face-shape reconstruction are presented within in this thesis.

In der biometrischen Gesichtserkennung kommen 3D - Rekonstruktionssysteme zum Einsatz, die eine berührungslose Erfassung der Gesichtsform mit einer großen Menge an 3D Punkten erlauben. Zur effektiven Verarbeitung dieser Daten ist eine semantische Zuordnung von Messpunkten zu der bekannten anatomischen Struktur des Gesichts erforderlich. Im Bereich der Anthropometrie und in technischen Standards sind Landmarken auf der Gesichtsoberfläche definiert, die sich an dieser Struktur orientieren und die Form und Variabilität des Gesichts beschreiben. In dieser Arbeit wird ein Verfahren vorgestellt das für 3D-Rekonstruktionen von beliebigen Gesichtern eine automatisierte Detektion von 11 solcher Landmarken durch Nutzung intrinsischer Oberflächenparameter ermöglicht. Die Landmarkenlokalisierung erfolgt durch Anpassung eines allgemeinen Landmarkenmodells, das auf den lokalen Krümmungseigenschaften der Landmarken basiert. Die Krümmungsanalyse der Oberfläche erfolgt mit Hilfe der eingebetteten Weingartenmatrix und die Krümmungsähnlichkeit wird als Übereinstimmungskriterium der Oberflächenpartien verwendet. Um die Funktionalität und Robustheit des Verfahrens zu überprüfen, wurden Versuche durchgeführt, in den getestet wurde, ob in verschiedenen Gesichtsrekonstruktionen derselben Person die lokalisierte Positionen der Landmarken Übereinstimmen und ob die Variation der Startposition der Suche einen signifikanten Einfluss auf die Effizienz der Lokalisierung hat. Für die Landmarken in Bereichen, die sich mit einem gleichmäßigen Krümmungsverlauf charakterisieren, werden dieselben Merkmalspunkte lokalisiert, auch unabhängig vom Anfangspunkt. In Landmarkenumgebungen mit einer ungleichförmigen Oberflächenbeschaffenheit dagegen, können sich Störungen in den Eingabedaten signifikant auf die Ergebnisse auswirken. Im Allgemeinen ist die Detektion von 3 bis 5 Landmarken in jeder Gesichtsrekonstruktion erfolgreich, wobei bei den restlichen das Ergebnis von der Empfindlichkeit der Krümmungsapproximation gegenüber Messstörungen, in Abhängigkeit von der Oberflächenstruktur, beeinflusst wird.

Brömme, Arslan (Ed.) et al.: BIOSIG 2011 : Proceedings - International Conference of the Biometrics Special Interest Group. Bonn: Köllen, 2011. (GI-Edition - Lecture Notes in Informatics (LNI) P-191), pp. 283-290

Biometrische Verfahren zum Schutz von kritischen Infrastrukturen sind in der heutigen Zeit geeignet, den Prozess der Gefahrenabwehr im Bereich der Grenzabfertigung und der Luftsicherheitskontrolle signifikant zu unterstützen. Angesichts der stetig weiter steigenden Passagieranzahl im Luftverkehr und neuer Bedrohungsszenarien, wie beispielsweise körperintegrierte Bomben, werden aktuell verschiedene Lösungsstrategien und -ansätze, zu den notwendigen Grenz- und Sicherheitskontrollen in den entsprechenden Expertenkreisen. diskutiert. IATA hat beginnend mit dem Simplified Passenger Travel Programm (SPT) und aktuell mit Secure Checkpoint of the Future [BTM 11] versucht dieser Komplexität Rechnung zu tragen. Frontex als europäische Grenzschutzagentur begleitet aktiv mit ,,New Ideas on Border Management" (BKüS] interessante Entwicklungen auf diesem Gebiet. Beispiele für automatisierte Grenzkontrollen (Automatic Border Control - ABC) reichen von miSense Großbritannien über Speed Hongkong und EasyPass Deutschland bis Vision-Box Portugal [VBl1]. Maschinenlesbare Ausweise mit biometrischen Merkmalen (Machine Readable Travel Documents - MRTD) verbunden mit einer interaktiven Passagierinformation (interactive Advance Passenger Information - iAPI) und einem risikobasierten Passagierkontrollverfahren sollen die Grundlagen bilden. Eine fehlende Harmonisierung, eine nicht vorhandene globale Interoperabilität und mangelndes zwischenstaatliches Vertrauen haben eine internationale Umsetzung bisher behindert. Die Herausforderung besteht darin, sich weiteren künftigen Szenarien zu stellen, effiziente Abfertigungs- und Kontrollinfrastrukturen vorzuhalten, die im Einklang mit den Sicherheitsbestimmungen, der Menschenwürde der Passagiere aber auch der Mitarbeiter der Behörden und beauftragten Unternehmen. Eine nachhaltige belastbare Vertrauensbildung sollte hier Richtlinie sein. Das Konzept der "PreBorderLane Embedded in Gate of TrustTM" reiht sich hiermit sinnvoll in diese Aktivitäten ein [MKH08j. Es versteht sich als biometrisch-grenzpolizeiliches Modul des ganzheitlichen Gate of Trust Konzeptes, das sich als internationale Forschungsplattform für nachhaltige Lösungen in diesem Umfeld anbieten möchte.

IEEE Computer Society: Proceedings of the 2011 IEEE 1st International Network Science Workshop : NSW 2011. Printing House, 2011, pp. 67-74

Connectivity and security of tactical mobile ad hoc networks (MANETs) can be enhanced significantly by explicit consideration of radio propagation as this not only allows determination of route feasibility and minimization of radio frequency power, but also avoids detectability of emanations. Tactical MANETs (and increasingly general MANETs) typically have geolocation and terrain information available, however as they are likely to be deployed in urban, broken, or indoor environments, simple Free Space or Two-Ray Ground models are not adequate. Although highly accurate radio propagation models exist, they require considerable computational resources and are hence unsuitable for incorporation into real-time protocols, particularly on resource-constrained platforms such as MANET nodes. We therefore propose a simplified, scalable ray-optical radio frequency propagation model that incorporates a Two-Ray Ground model and takes reflections and deflections on terrain features into account. Although our proposed model does not incorporate a comprehensive model of all physical effects, we argue that the approximation provided by our model is sufficient and suitable for the purposes of enhancing network performance and accuracy in the frequency range currently used by wireless networks. The model was incorporated in the NS-2 simulator and validated both using simulation and experimentally.

4th International Conference on Human System Interaction. Proceedings : HSI 2011. New York: IEEE Press, 2011, pp. 293-298

In this paper we present some results of ongoing work on a case study that combines an employee portal with the monitoring of physical activity of the employee during his working time. The essence of this case study is to show how information about the worker's individual physical activity can be presented online in a comprehensive way together with the actual portal information. This allows not only the employee, but also therapists and health consultants to analyze physical activity and rest periods during the work in conjunction with the corresponding work description. The purpose of our case study is to promote physical activity as a key employee health management strategy. And for this, our results show that even with low cost and little technical effort, current mobile and web technologies can simplify the acquisition of sensor data and the integration into existing systems. We want to motivate especially small and middle-sized companies to consider the integration of physical-activity monitoring to preserve the health and well-being of their employees. Promoting the employees health is an investment in the company's human capital and can reduce the risk of i.e. Diabetes and cardiovascular diseases. In opposite to large enterprises where health-management has been well established, small companies can often not effort the cost for enterprise health and prevention management systems and the implementation by specialists. We have developed a lightweight Web API that provides easy access to the physical-activity data and function for visualization. We demonstrate how the API is applied together with the employee portal.

Lindstaedt, Stefanie (Ed.) et al.: i-KNOW '11. Proceedings : 11th International Conferences on Knowledge Management and Knowledge Technologies. New York: ACM, 2011. (ACM International Conference Proceedings Series 541), 8 p.

The modular logistic transport of goods on streets, railroads, inland water and sea is a complex and versatile process. It requires exact knowledge of geographic information, available logistical service providers and communication channels. This application paper describes IMOTRIS, an automated Intermodal Transport Routing Information System which is developed as a state-aided collaborative project that benefits from practical experience by contributions from different ports and transport service providers. We present a novel approach which combines service-oriented multi-modal route planning with semantic web technologies for the selection and ranking of transport and turnover services to create suitable and optimized complex logistic service chains. We utilize committed semantic descriptions of logistic services and their relationships with regard to the application context.

The development of efficient and stable fluid simulations is a challenging task in computer graphics. Elcott et al. [6] describe an approach, based on Discrete Exterior Calculus for simulating the fluid flow. A vorticity based formulation of the incompressible Navier-Stokes equations is used, resulting in a mass-conserving representation of the velocity field by definition. This approach preserves vorticity at a discrete level, resulting in a visually more realistic fluid flow. We extend this approach to regular grids in two dimensions. So, we avoid computationally expensive mesh constructions. We discuss non-trivial boundary conditions and arbitrary topologies. The vorticity conservation properties are compared with the classical mesh based approach of Elcott et. al. We especially analyze the corresponding pressure fields near the boundaries of inner objects.

Stephanidis, Constantine (Ed.): Universal Access in Human-Computer Interaction: Part III : Context Diversity. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6767), pp. 220-229

AAL Solutions are not part of mainstream industry yet, being one of the main reasons the complexity of the technologies involved in relation to its targeted beneficiaries, the elderly, and its acceptance by them. Applying HCD methodologies for user involvement and creating physical prototypes is both costly and time consuming, particularly in this domain that combines software artifacts, devices and physical environments. VR techniques are very suited to create Virtual Prototypes that offer the beneficiaries the possibility to visualize and interact with proposed solutions before they exist. This paper presents the results of VAALID project in developing this approach of creating tools for design and simulation of AAL Solutions using VR and Mixed Reality, supporting the early involvement of beneficiaries in the process.

Shumaker, Randall (Ed.): Virtual and Mixed Reality - New Trends: Part I : International Conference, Virtual and Mixed Reality 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6773), pp. 270-279

This paper introduces a new low-cost, laser-based 6DOF interaction technology for outdoor mixed reality applications. It can be used in a variety of outdoor mixed reality scenarios for making 3D annotations or correctly placing 3D virtual content anywhere in the real world. In addition, it can also be used with virtual back-projection displays for scene navigation purposes. Applications can range from design review in the architecture domain to cultural heritage experiences on location. Previous laser-based interaction techniques only yielded 2D or 3D intersection coordinates of the laser beam with a real world object. The main contribution of our solution is that we are able to reconstruct the full pose of an area targeted by our laser device in relation to the user. In practice, this means that our device can be used to navigate any scene in 6DOF. Moreover, we can place any virtual object or any 3D annotation anywhere in a scene, so it correctly matches the user's perspective.

Diese Arbeit gibt einen Einblick in die Grundlagen der 3D-Anwendungen im Zusammenspiel mit verschiedenen Customer Devices. In diesem Fall ist die Anwendung ein 3D-Planetarium unseres Sonnensystems für ein Museum. Ziel ist es, ein Konzept zur intuitiven und immersiven Navigation durch das virtuelle Planetarium mittels preiswerte Customer Devices zu erstellen. Die Besucher sollen sich frei und ohne großen Aufwand im Sonnensystem bewegen können. Dabei soll sich der Besucher auf die Simulation konzentrieren können und nicht durch komplexe Steuerung schnell das Interesse an der Anwendung verlieren. Dafür werden vergleichbare Ansätze und der bisherige Forschungsstand untersucht und ein neuer Ansatz beschrieben. Als kostengünstige Customer Devices werden in dieser Arbeit die Controller der Nintendo Wii (Wiimote) und aktuelle Smartphones betrachtet. Eine genaue Analyse dieser Geräte ist Bestandteil dieser Arbeit. Ausgehend von den gewählten Geräten gibt es verschiedene Interaktionsmöglichkeiten und daraus resultierende Interaktionskonzepte. Für jedes Gerät soll ein Konzept entwickelt werden, das die gestellten Ansprüche erfüllt.

In der Geschäftswelt sind es gerade die kleinen und mittelständischen Unternehmen, die gezwungen sind, ihre Produktion so effizient wie möglich zu gestalten, um ihre Chancen auf dem Markt zu bewahren. Häufig führt dies langfristig zu einer notwendigen Optimierung des Betriebes, bei der vermehrt die Geschäftsprozesse eines Unternehmens und deren Automatisierung in den Fokus rücken. Diese Arbeit beschäftigt sich mit Möglichkeiten zur integrierten und einfachen Modellierung dieser Geschäftsprozesse mit dem Ziel der Automatisierung unter Berücksichtigung realer Unternehmensstrukturen, ohne dass explizites Fachwissen seitens der Modellierer nötigt ist. In diese automatisierten Prozesse sollen zudem Formulare und Eingabemasken integriert werden, damit eine Kommunikation und Interaktion der Nutzer mit dem ausführenden System möglich wird. Entsprechende Systeme existieren, sind in der Regel aber durch die Vernachlässigung realer Strukturen und einer zu komplizierten Bedienung gekennzeichnet. Nach der Erläuterung von theoretischen Grundlagen zur Modellierung von Geschäftsprozessen und Anforderungen an ein mögliches Modellierungswerkzeug wird dazu der Prototyp eines intuitiven, praxistauglichen System entwickelt, mit dem eine einfache, nutzerfreundliche Modellierung und Ausführung von Geschäftsprozessen mit integrierten Prozessdialogen zur Ablaufsteuerung, Monitoring-Zwecken und Dateneingabe möglich wird.

Adipositas Spektrum, Vol.7 (2011), 2, pp. 12-14

Im Zeitraum 2008 bis 2010 wurde an der Medigreif Inselklinik Heringsdorf GmbH, Fachklinik für Diabetes und Stoffwechselkrankheiten, Ostseebad Heringsdorf, im Rahmen einer klinischen Studie untersucht, ob telemedizinische Anwendungen in die Therapie von Kindern und Jugendlichen mit Übergewicht und Adipositas erfolgreich einbezogen werden können. Dazu wurden 124 Kinder/Jugendliche (Alter 13,5 ± 2,8 Jahre, BMI 31,3 ± 5,2 kg/m², BMI-SDS 2,50 ± 0,5) mit einem Mobiltelefon ausgerüstet, das einen Sensor und spezielle Software zur Erfassung von Bewegungen und Ernährung enthält (DiaTrace). Durch den Einsatz dieser Teletechnologie konnte nachgewiesen werden, dass viele übergewichte und adipöse Kinder und Jugendliche ihre körperliche Bewegung und Ernährung falsch positiv einschätzen. Die Motivation zur Gewichtsabnahme konnte gesteigert und durch regelmäßiges Monitoring eine effektivere Nachhaltigkeit erzielt werden. Dieses resultiert in einer hohen Akzeptanz der Teletechnologie und im Vergleich zur herkömmlichen Therapie in einer stärkeren Gewichtsreduktion. Teletechnologie, bestehend aus einem System zur objektiven Bewegungs- und Ernährungserfassung stellt somit ein neues Instrument zur effektiven Therapie bei Kindern und Jugendlichen mit Übergewicht und Adipositas dar. Eine Gewichtsreduktion und -stabilisation kann so sinnvoll unterstützt werden.

Experimental and Clinical Endocrinology & Diabetes, (2011), eFirst. 6 April 2011. DOI: 10.1055/s-0031-1273747, 4 p.

To assess physical activity in patients with type 1 diabetes an innovative telemedical support system has been developed. The aim of the feasibility trial was to prove its use in a clinical setting. Patients/methods: 16 children/adolescents with type 1 diabetes mellitus aged 14.5±2.2 years (diabetes duration 6.5±3.6 years, HbA1c 8.8±1.0%) were included in the study. During a period of 1-3 days all the patients received a telemedical assessment system. It consists of a sensor for physical activity integrated into a mobile phone (DiaTrace). Additionally it is combined with a system for continuous blood glucose monitoring (CGM). Results: The technical system was highly accepted by all the 16 children and adolescents. Physical activity measured was 13.3±5.5 AU/d, mean duration of total physical activity was 204.9±66.5 min/d (walking 102.5±62.5, running 7.4±5.8, cycling 39.2±32.7, driving 36.0±18.6, non-specific physical activity 57.0±29.7 min/d). Periods without activity lasted for 386.5±187.2 min/d. Daily energy expenditure was 1 964.1±185.5 kcal/d. Correlations between physical activity (measured with DiaTrace) and blood glucose profiles (measured with CGM) were calculated. Pearson's correlation coefficients ranged between 0.59 and 0.99 (median 0.91). Hence, these good correlation coefficients show the high and direct association between blood glucose values and activity units. The wide ranges in correlation coefficients demonstrate a huge variability of individualized reactions. Conclusions: Use of innovative electronic health technology is highly accepted by patients. It reveals an accurate, real-time assessment of an individual's physical activity. These Information can use for insulin dose-adjustment.

D'Mello, Sidney (Ed.) et al.: Affective Computing and Intelligent Interaction. Fourth International Conference : ACII 2011. Berlin; Heidelberg; New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6974), pp. 316-325

The present paper describes the specification of Emotion Markup Language (EmotionML) 1.0, which is undergoing standardisation at the World Wide Web Consortium (W3C). The language aims to strike a balance between practical applicability and scientific wellfoundedness. We briefly review the history of the process leading to the standardisation of EmotionML. We describe the syntax of EmotionML as well as the vocabularies that are made available to describe emotions in terms of categories, dimensions, appraisals and/or action tendencies. The paper concludes with a number of relevant aspects of emotion that are not covered by the current specification.

Petta, Paolo (Ed.) et al.: Emotion-Oriented Systems : The Humaine Handbook. Berlin, Heidelberg, New York: Springer, 2011. (Cognitive Technologies), pp. 369-387

In many cases when technological systems are to operate on emotions and related states, they need to represent these states. Existing representations are limited to application-specific solutions that fall short of representing the full range of concepts that have been identified as relevant in the scientific literature. The present chapter presents a broad conceptual view on the possibility to create a generic representation of emotions that can be used in many contexts and for many purposes. Potential use cases and resulting requirements are identified and compared to the scientific literature on emotions. Options for the practical realisation of an Emotion Markup Language are discussed in the light of the requirement to extend the language to different emotion concepts and vocabularies, and ontologies are investigated as a means to provide limited "mapping" mechanisms between different emotion representations.

IEEE Computer Society: 2011 Third International Conference on Games and Virtual Worlds for Serious Applications : VS-Games. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, pp. 136-139

Dynamic area and volume lights are a common phenomenon in our world. Examples include illuminated advertising, video screens, and lava lamps. Yet rendering such light sources in real-time in interactive scenes remains challenging. In this paper we present a method to render area or volume light sources in a fully dynamic scene, i.e. the geometry, materials, camera, and lights (spatial and spectral composition) can change continuously. The key idea of our approach is to decouple lighting from shading complexity by using a dynamically generated hierarchy of irradiance volumes as an intermediate approximation of incident lighting. The main contribution of this paper is a new computation scheme that updates irradiance volumes directly on the GPU and enables real-time performance. The algorithm is very fast, runs on DX9-level hardware, and is easy to integrate into existing rendering pipelines, which makes it well-suited for games and virtual-reality applications. Current limitations of our algorithm are that it cannot handle shadows and provides only a coarse approximation for glossy reflection.

ACM SIGGRAPH: Proceedings Web3D 2011 : 16th International Conference on 3D Web Technology. New York: ACM Press, 2011, pp. 39-44

Rendering volumetric phenomena with believable appearance can add tremendous realism to virtual scenes. We introduce the CommonVolumeShader node, an extension of the X3D standard which has been specifically designed for physically-based rendering of participating media. CommonVolumeShader allows content authors to specify optical properties in a concise and purely declarative way and can accurately capture the appearance of many volumetric phenomena. We demonstrate results with implementations for an interactive ray tracer and a rasterization-based pipeline.

Avis, Nick (Ed.) et al.: Eurographics 2011. Short Papers. Eurographics Association, 2011, pp. 25-28

Monte Carlo estimation of direct lighting is often dominated by visibility queries. If an error is tolerable, the calculations can be sped up by using a simple scalar occlusion factor per light source to attenuate radiance, thus decoupling the expensive estimation of visibility from the comparatively cheap sampling of unshadowed radiance and BRDF. In this paper we analyze the error associated with this approximation and derive an upper bound. We demonstrate in a simple relighting application how our result can be used to reduce noise by introducing a controlled error if a reliable estimate of the visibility is already available.

Heuser, Lutz (Ed.) et al.: Internet der Dienste. Berlin, Heidelberg, New York: Springer, 2011. (acatech DISKUTIERT), pp. 19-40

Wissen und Informationen wachsen nicht nur stetig in ihrer Menge, sie stellen heute vielmehr eine bedeutende Ressource vieler Unternehmen dar. Der effiziente Zugriff auf Unternehmenswissen, wie etwa Expertisen, Ansprechpartner, Projekt- und Meilensteinpläne etc. kann Unternehmensprozesse vereinfachen und somit zur Zeit- und Kostenreduktion beitragen. Semantische Technologien bieten zahlreiche Möglichkeiten, um Daten mit Hintergrundinformationen zu ihrer Bedeutung anzureichern und sie mit weiteren relevanten Informationseinheiten zu verbinden. Solche semantische Relationen führen nicht nur zu einer effizienteren Suche in größeren Informationsräumen, sondern unterstützen den Benutzer auch bei diversen Prozessen, wie etwa Editierung, Annotation und Verarbeitung von Informationen. Die komplexen semantischen Strukturen stellen neue Herausforderungen an die Visualisierung dar. SemaVis eine am Fraunhofer IGD entwickelte Kerntechnologie stellt eine komponentenbasierte, modulare Architektur zur Semantik-Visualisierung zur Verfügung, die die Anwendbarkeit der Visualisierungen in verschiedenen Anwendungsszenarien unter Nutzung heterogener Daten für heterogene Benutzer erlaubt.

Jacko, Julie A. (Ed.): Human-Computer Interaction: Part IV : Users and Applications. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6764), pp. 520-529

Time appears in many different semantic information systems like historical databases, multimedia systems or social communities as a common attribute. Beside the temporal information, the resources in these domains are categorized in a domain-specific schema and interconnected by semantic relations. Nevertheless, the high potential of these systems is not yet exhausted completely. Even today most of these knowledge systems present timedependent semantic knowledge in textual form, what makes it difficult for the average user to understand temporal structures and dependencies. For bridging this gap between human and computer and for simplifying the exploration of time-dependent semantic knowledge, we developed a new interactive timeline visualization called SemaTime. The new designed temporal navigation concept offers an intuitive way for exploring and filtering time-depended resources. Additionally SemaTime offers navigation and visual filtering methods on the conceptual layer of the domain and is able to depict semantic relations. In this paper we describe the conceptual design of SemaTime and illustrate its application potentials in semantic search environments.

Dawant, Benoit M. (Ed.) et al.: Medical Imaging 2011: Image Processing. Part One : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 12, No. 31. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7962), pp. 79621V-1 - 79621V-6

The joint extraction of texture features from medical images of different modalities requires an accurate image registration at the target structures. In many cases rigid registration of the entire images does not achieve the desired accuracy whereas deformable registration is too complex and may result in undesired deformations. This paper presents a novel region of interest alignment approach based on local rigid registration enabling image fusion for multimodal texture feature extraction. First rigid registration on the entire images is performed to obtain an initial guess. Then small cubic regions around the target structure are clipped from all images and individually rigidly registered. The approach was applied to extract texture features in clinically acquired CT and MR images from lymph nodes in the oropharynx for an oral cancer reoccurrence prediction framework. Visual inspection showed that in all of the 30 cases at least a subtle misalignment was perceivable for the globally rigidly aligned images. After applying the presented approach the alignment of the target structure significantly improved in 19 cases. In 12 cases no alignment mismatch whatsoever was perceptible without requiring the complexity of deformable registration and without deforming the target structure. Further investigation showed that if the resolutions of the individual modalities differ significantly, partial volume effects occur, diminishing the significance of the multimodal features even for perfectly aligned images.

IEEE Engineering in Medicine and Biology Society (EMBS): 2011 IEEE International Symposium on Biomedical Imaging: From Nano to Macro : ISBI 2011. New York: IEEE Press, 2011, pp. 1990-1993

An automatically extracted 2d contour of a lymph node in a single CT slice is required for size assessment as well as for the initialization of model based 3d lymph node segmentation algorithms. This paper presents a novel single slice lymph node segmentation approach. It finds a closed path around a seed point thereby minimizing an energy function which depends on gradients, intensities and shape priors. A globally optimal solution is guaranteed to be found using dynamic programming. The approach is evaluated on a set of 49 representative lymph nodes from clinical images for which manual expert segmentation is available. The resulting average dice similarity coefficient of 0.81 is close to manual segmentation (0.89).

Academic Radiology, (2011), Article in Press. Corrected Proof 7 January 2011. DOI: 10.1016/j.acra.2010.11.010, 4 p.

Rationale and Objectives: In today's clinical practice, the size of lymph nodes is assessed by measuring the long and the short axis in the axial plane. This study compares this approach with three-dimensional (3D) assessment. Materials and Methods: For a representative set of 49 lymph nodes, the axes in the axial plane have been measured and a 3D model has been created manually. Based on the 3D model, the real axial long and short axis as well as the three 3D axes and the volume have been computed and compared to the measured axial axes. Results: The inter-observer variability is around 10% for all measured lengths and almost 16% for the computed volume. The average relative error of the measured long (short) axial axis is 9.73% (24.57%) to the computed axial axis and 25.05% (19.97%) to the computed 3D axis, respectively. The product of the axial long axis and the square of the axial short axis provide best correlation to the volume. Conclusion: This study confirms Response Evaluation Criteria in Solid Tumors 1.1 that measuring the short axis is more robust than measuring the long axis because of less impact of the node's spatial orientation. Nonetheless it is shown that considering both axes is a better prognostic factor for the volume than measuring the short axis only.

Bundesanstalt für Gewässerkunde (BfG): Zeitgemäße Erfassung und Bereitstellung von Geobasisdaten für die WSV. Koblenz: Druckerei Fuck, 2011. (Veranstaltungen der Bundesanstalt für Gewässerkunde 3/2011), pp. 101-109

Das dem vorliegenden Beitrag zugrundeliegende Projekt untersucht, inwieweit sich Ansätze der Geometrieanalyse aus industriellen Anwendungen auf das Problem der Definition von Wasser-Land-Grenzen adaptieren lassen. Ein Ziel dabei ist die Minimierung von Benutzerinterventionen. Als erweiterte Lösungsidee liegt unserem Ansatz eine Kombination aus Geometrieanalyse und der Einbeziehung zusätzlicher Informationen aus Geobasisdaten, namentlich der vektoriellen Beschreibung von Verläufen von Wasserstraßen in ATKIS-Daten, zugrunde.

Störungsfälle im Bereich der Großanlagen stellen, auf Grund des erforderlichen Expertenwissens und der meist großen räumlichen Distanz zwischen dem Fertigungsort und dem Anlagenstandort, ein großes Problem dar. Um dennoch die Kenntnisse eines Experten nutzen zu können, wird häufig auf Telefon- oder Videokonferenztechniken zurückgegriffen. Diese Techniken limitieren allerdings die Interaktionsmöglichkeit des Experten mit der fernen Anlage. Speziell die unabhängige Untersuchung der Anlage durch den Remoteexperten ist ein großes Problem. Ziel dieser Arbeit ist es, Methoden zu entwickeln und zu untersuchen, die dem Experten mehr Freiheiten bietet, um Informationen über den Zustand einer Anlage zu erhalten und den Monteur vor Ort effektiver zu unterstützen.

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 4. AAL-Kongress 2011. Berlin: Springer Science+Business Media, 2011. (Advanced Technologies and Societal Change), pp. 141-155

Due to the changing demographics, residing and being cared in the own familiar environment is becoming the more attractive alternative for an ever increasing portion of the population in contrast to an institutionalized inpatient setting. Despite its tremendous market potential, AAL (Ambient Assisted Living) is still on the cusp of a mainstream break-through. A lack of viable business models is considered almost unanimously to be the greatest market obstacle to a broad implementation of innovative AAL systems. This paper highlights possible explanations for this deficit and shows why the AAL community has yet to arrive at joint solutions based on a unified AAL reference platform. Furthermore, this paper describes the enormous potential of AmI and AAL, as the first real opportunity for their success is provided through universAAL and AALOA.

ACM SIGGRAPH: Proceedings Web3D 2011 : 16th International Conference on 3D Web Technology. New York: ACM Press, 2011, pp. 165-172

With the success of applications providing geospatial 3D data to end-users via virtual globes and web-based services, the need for accessing more accurate and up-to-date information has come up. Geodata typically comes from different and unrelated sources, whereas users expect a seamless view which respects their specific needs. A modern geo portrayal service therefore has to deliver information from heterogeneous data sources adapted to specific applications. Each data model introduces limitations that might make it harder to fulfil user requirements. Since in practise user requirements constantly change and data sets are updated, the complexity of configuring and administering such a process increases disproportionately to both the number of requirements and data model limitations. To overcome this situation, we outline an approach which seeks to avoid what we call the explosion of interdependencies between formalized requirements and geodata features. Our goal is to keep original data virtually untouched while delivering adapted data to multiple users with specific portrayal requirements. We therefore introduce an intermediate representation (IR) to alleviate the growing complexity of interdependencies from O(n x m) to O(n + m). We adapt this technique to the geospatial domain, deriving a prototypical implementation of an OGCWeb 3D Service which delivers X3D documents. The service is capable of adapting to user requirements and at the same time serving originally heterogeneous geodata. We introduce the implementation, discuss results and application opportunities.

Geographische Informationen finden durch die wachsende Verbreitung von satellitengestützten Ortungssystemen vermehrt Einzug in digitale Informationssysteme. Beispielsweise enthalten digitale Medien orts- und zeitbezogene Informationen und auch in sozialen Netzwerken teilen Personen Routenaufzeichnungen oder ihren aktuellen Standort. Zusätzlich werden die digitale Ressourcen in modernen Informationssystemen zunehmend durch semantische Technologien modelliert und miteinander vernetzt, wodurch neue Möglichkeiten für die Wissensverarbeitung und -suche hervorgehen. Dennoch wird das hohe Potential dieser Informationssysteme noch nicht komplett ausgeschöpft, insbesondere wenn es darum geht das vorhandene Wissen in adäquater Weise an den Benutzer zu vermitteln. In dieser Arbeit wird ein Konzept für die interaktive Visualisierung von zeitlich und geographisch annotierten semantischen Informationen vorgestellt, dass dem Benutzer unter Verwendung semantischer Informationen den Umgang mit komplexen geographischen Daten erleichtert. Neben einer Klassifikation von geographischen Informationen werden existierende Konzepte für die Visualisierung von geographischen, zeitlichen und semantischen Daten vorgestellt sowie vergleichend gegenübergestellt. Das entwickelte Konzept liefert Beiträge sowohl für die Visualisierung von zeitlichen-geographischen Informationen als auch für die Verwendung und Darstellung semantischer Informationen im geographischen Umfeld. Beide Aspekte werden in einem einheitlichen Konzept vereint und dessen Anwendung beispielhaft in einem Sozialen-Netzwerk-Szenario präsentiert.

Laga, Hamid (Ed.) et al.: 3D Object Retrieval 2011 : Eurographics Symposium Proceedings. Goslar: Eurographics Association, 2011. (Eurographics Workshop and Symposia Proceedings Series), pp. 1-8; 125 (Color plate)

"What is the difference between a cup and a door?" These kinds of questions have to be answered in the context of digital libraries. This semantic information, which describes an object on a high, abstract level, is needed in order to provide digital library services such as indexing, mark-up and retrieval. In this paper we present a new approach to encode and to extract such semantic information. We use generative modelling techniques to describe a class of objects: each class is represented by one algorithm; and each object is one set of high-level parameters, which reproduces the object if passed to the algorithm. Furthermore, the algorithm is annotated with semantic information, i.e. a human-readable description of the object class it represents. We use such an object description to recognize objects in real-world data e.g. laser scans. Using an algorithmic object description, we are able to identify 3D subparts, which can be described and generated by the algorithm. Furthermore, we can determine the needed input parameters. In this way, we can classify objects, recognize them semantically and we can determine their parameters (cup's height, radius, etc.).

IEEE Computer Graphics and Applications, Vol.31 (2011), 2, p. 58-66

This tutorial presents probability theory techniques for boosting linear algorithms. The approach is based on statistics and uses educated guesses instead of comprehensive calculations. Because estimates can be calculated in sublinear time, many algorithms can benefit from statistical estimation. Several examples show how to significantly boost linear algorithms without negative effects on their results. These examples involve a Ransac algorithm, an image-processing algorithm, and a geometrical reconstruction. The approach exploits that, in many cases, the amount of information in a dataset increases asymptotically sublinearly if its size or sampling density increases. Conversely, an algorithm with expected sublinear running time can extract the most information.

Remondino, Fabio (Ed.) et al.: Proceedings of the 4th ISPRS International Workshop 3D-ARCH 2011 : 3D Virtual Reconstruction and Visualization of Complex Architectures [CD-ROM]. (The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XXXVIII-5/W16), 5 p.

The need to analyze and visualize differences of very similar objects arises in many research areas: mesh compression, scan alignment, nominal/actual value comparison, quality management, and surface reconstruction to name a few. In computer graphics, for example, differences of surfaces are used for analyzing mesh processing algorithms such as mesh compression. They are also used to validate reconstruction and fitting results of laser scanned surfaces. As laser scanning has become very important for the acquisition and preservation of artifacts, scanned representations are used for documentation as well as analysis of ancient objects. Detailed mesh comparisons can reveal smallest changes and damages. These analysis and documentation tasks are needed not only in the context of cultural heritage but also in engineering and manufacturing. Differences of surfaces are analyzed to check the quality of productions. Our contribution to this problem is a workflow, which compares a reference / nominal surface with an actual, laser-scanned data set. The reference surface is a procedural model whose accuracy and systematics describe the semantic properties of an object; whereas the laser-scanned object is a real-world data set without any additional semantic information.

Mobile Kommunikationssysteme mit multimedialer Ausstattung durchdringen langsam aber sicher unser Gesellschaftsbild und fügen sich aufgrund ihres umfassenden Potentials immer mehr als ambiente Unterstützung in das Alltags- und Berufsleben ein. Die sprachbasierte Erkennung von Situationen mit mobilen Endgeräten ist dabei ein Betrachtungspunkt, welcher durch die sich nun bildenden Möglichkeiten ein Forschungs- und Entwicklungsziel ergibt. In dieser Bachelorarbeit soll das grundlegende Konzept einer mobilen Situationserkennung, das Implementierungskonzept im Anwendungsbereich der Nahrungserfassung dargestellt sowie eine prototypische Anwendung der sprachbasierten Nahrungserfassung aufgezeigt werden.

Die Nahrungserfassung mit mobilen Endgeräten ist ein immer wichtiger werdendes Gebiet der Ernährungsforschung. Im Rahmen der gesunden Lebensweise ist eine leicht zu bedienende und möglichst genaue Anwendung, welche vorliegende Mahlzeiten identifiziert, von großem Vorteil. In dieser Literaturarbeit werden grundsätzliche Methoden der statistischen Nahrungserhebung erläutert sowie bereits entwickelte Konzepte und Prototypen gezeigt. Diese werden entsprechend ihrer eingesetzten Techniken kategorisiert und auf Besonderheiten sowie Schwachstellen untersucht.

The American Society of Mechanical Engineers (ASME): ASME 2011 World Conference on Innovative Virtual Reality : WINVR 2011. New York: The American Society of Mechanical Engineers, 2011, 6 p.

Digital Mock-Up (DMU) is a widely introduced technology to virtually investigate geometrical and mechanical product properties. Functional Digital Mock-Up (FunctionalDMU) is a combination of traditional DMU with behavioral simulation in mechatronics. Enhancing DMU with functional aspects, considerably more insight in product properties can be gained. To enable FunctionalDMU two main tasks have to be solved: a) simulators in the areas of mechanics, electronics, and software simulation have to talk to each other (coupling) and b) the simulation results have to be visualized in an interactive DMU environment. In this paper we present an independent and open approach to a FunctionalDMU framework including co-simulation. Starting with proprietary and natively given behavior and geometric models (in formats like JT), we wrap the behavior models into SysML to enable data exchange on an agreed and standardized format. The native behavior models still are executed in the corresponding simulators. The simulators are linked to the FunctionalDMU framework using a wrapping approach. Currently we support simulators such as Matlab/Simulink, Dymola, Saber, Rhapsody, SimPack, ANSYS with our framework. During simulation a simulator coupling algorithm controls the simulation processes. A dedicated visualization environment enables the user to interact with the simulation, i.e., to send simulation stimuli, change parameters, observe the simulation run etc. This paper introduces the components of the FunctionalDMU framework and illustrates the approach with an application example.

Bergamasco, Massimo (Ed.) et al.: Skill Learning and Virtual Environments : Skills Summer School 2011. Pisa: Mnemosyne & Percro, 2011, pp. 63-66

Augmented Reality (AR) based training is a current trend being investigated by several research efforts applying specific new concepts such as educational games and platforms for ICT enabled learning experiences. Hence, due to the fact that recreational computer games are extremely popular with people of any age, there is no doubt that 3D training environments determine the trend in the future of training assistance. In this context AR environments can offer the possibility for trainees to interact with the real environment (e.g. a complex industrial machine) and with virtual objects that are linked to the real environment and provide additional information. This requires the development of training platforms that offer a flexible and coherent technical infrastructure, which supports the use of Augmented Reality with different training settings in different training application domains.

Alem, Leila (Ed.) et al.: Recent Trends of Mobile Collaborative Augmented Reality Systems. Berlin, Heidelberg, New York: Springer, 2011, pp. 69-82

Training for service technicians inmaintenance tasks is a classical application field of Augmented Reality explored by different research groups. Mostly technical aspects (tracking, visualization etc.) have been in focus of this research field. In this chapter we present results of interdisciplinary research based on the fusion of cognitive science, psychology and computer science. We focus on analyzing the improvement of Augmented Reality based training of skills which are relevant for maintenance and assembly tasks. The skills considered in this work comprise sensorimotor skills as well as cognitive skills. Different experiments have been conducted in order to find recommendations for the design of Augmented Reality training systems which overcome problems of existing approaches. The suggestions concern the fields of content visualization and multimodal feedback.

BIO Web of Conferences, Vol.1 (2011), 4 p.

Augmented Reality (AR) points out to be a good technology for training in the field of maintenance and assembly, as instructions or rather location-dependent information can be directly linked and/or attached to physical objects. Since objects to maintain usually contain a large number of similar components (e.g. screws, plugs, etc.) the provision of location-dependent information is vitally important. Another advantage is that AR-based training takes place with the real physical devices of the training scenario. Thus, the trainee also practices the real use of the tools whereby the corresponding sensorimotor skills are trained.

Shumaker, Randall (Ed.): Virtual and Mixed Reality - New Trends: Part I : International Conference, Virtual and Mixed Reality 2011. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6773), pp. 123-132

As the complexity of maintenance tasks can be enormous, the efficient training of technicians in performing those tasks becomes increasingly important. Maintenance training is a classical application field of Augmented Reality explored by different research groups. Mostly technical aspects (e.g tracking, 3D augmentations) have been in focus of this research field. In our paper we present results of interdisciplinary research based on the fusion of cognitive science, psychology and computer science. We focus on analyzing the improvement of AR-based training of maintenance skills by addressing also the necessary cognitive skills. Our aim is to find criteria for the design of AR-based maintenance training systems. A preliminary evaluation of the proposed design strategies has been conducted by expert trainers from industry.

The training of technicians in the acquisition of new maintenance and assembly tasks is an important factor in industry. As the complexity of these tasks can be enormous, the training of technicians to acquire the necessary skills to perform them efficiently is a challenging point. However, traditional training programs are usually highly theoretical and it is difficult for the trainees to transfer the acquired theoretical knowledge about the task to the real task conditions, or rather, to the physical performance of the task. In addition, traditional training programs are often expensive in terms of effort and cost. Previous research has shown that Augmented Reality is a powerful technology to support training in the particular context of industrial service procedures, since instructions on how to perform the service tasks can be directly linked to the machine parts to be processed. Various approaches exist, in which the trainee is guided step-by-step through the maintenance task, but these systems act more as guiding systems than as training systems and focus only on the trainees' sensorimotor capabilities. Due to the increasing complexity of maintenance tasks, it is not sufficient to train the technicians' execution of these tasks, but rather to train the underlying skills - sensorimotor and cognitive - that are necessary for an efficient acquisition and performance of new maintenance operations. All these facts lead to the need for efficient training systems for the training of maintenance and assembly skills which accelerate the technicians' learning and acquisition of new maintenance procedures. Furthermore, these systems should improve the adjustment of the training process to new training scenarios and enable the reuse of existing training material that has proven its worth. In this thesis a novel concept and platform for multimodal Augmented Reality-based training of maintenance and assembly skills is presented. This concept includes the identification of necessary sub-skills, the training of the involved skills, and the design of a training program for the training of maintenance and assembly skills. Since procedural skills are considered as the most important skills for maintenance and assembly operations, they are discussed in detail, as well as appropriate methods for improving them. We further show that the application of Augmented Reality technologies and the provision of multimodal feedback -and vibrotactile feedback in particular-have a great potential to enhance skill training in general. As a result, training strategies and specific accelerators for the training of maintenance and assembly skills in general and procedural skills in particular are elaborated. Here, accelerators are concrete methods used to implement the pursued training strategies. Furthermore, a novel concept for displaying location-dependent information in Augmented Reality environments is introduced, which can compensate tracking imprecisions. In this concept, the pointercontent metaphor of annotating documents is transferred to Augmented Reality environments. As a result, Adaptive Visual Aids are defined which consist of a tracking-dependent pointer object and a tracking-independent content object, both providing an adaptable level and type of information. Thus, the guidance level of Augmented Reality overlays in AR-based training applications can be easily controlled. Adaptive Visual Aids can be used to substitute traditional Augmented Reality overlays (i.e. overlays in form of 3D animations), which highly suffer from tracking inaccuracies. The design of the multimodal AR-based training platform proposed in this thesis is not specific for the training of maintenance and assembly skills, but is a general design approach for multimodal training platforms. We further present an implementation of this platform based on the X3D ISO standard which provides features that are useful for the development of Augmented Reality environments. This standard-based implementation increases the sustainability and portability of the platform. The implemented multimodal Augmented Reality-based platform for training of maintenance and assembly skills has been evaluated in industry and compared to traditional training methods. The results show that the developed training platform and the pursued training strategies are very well suited for the training of maintenance and assembly skills and enhance traditional training. With the presented framework we have overcome the problems sketched above. We are cheap in terms of effort and costs for the training of maintenance and assembly skills and we improve its efficiency compared with traditional training.

The Visual Computer, Vol.27 (2011), 6-8, pp. 473-483

We present a physically based interactive simulation technique for de formable objects. Our method models the geometry as well as the displacements using quadratic basis functions in Bernstein-Bézier form on a tetrahedral finite element mesh. The Bernstein-Bézier formulation yields significant advantages compared to approaches using the monomial form. The implementation is simplified, as spatial derivatives and integrals of the displacement field are obtained analytically avoiding the need for numerical evaluations of the elements' stiffness matrices. We introduce a novel traversal accounting for adjacency in order to accelerate the reconstruction of the global matrices. We show that our proposed method can compensate the additional effort introduced by the co-rotational formulation to a large extent. We validate our approach on several models and demonstrate new levels of accuracy and performance in comparison to current state-of-the-art.

International Association for the Engineering Analysis Community (NAFEMS): The Integration of CFD into the Product Development Process : Seminar. Glasgow: NAFEMS, 2011, 9 p.

An important step of the product development is the optimization of the components' physical behavior, which is usually done in a costly iterative process. Besides the modification, simplification, and (re-) meshing of the component's geometry, simulating its behavior can take hours or even days. In the early conceptual design phase, different material properties and shapes need to be tested and compared, in order to optimally design the component. Nonetheless, time consuming simulations limit the realm of possibilities. We have developed a framework for enabling rapid Computational Fluid Dynamics (CFD) for the early conceptual design phase. In order to achieve this, we combine the computation and visualization of 2D fluid flow in real time with the modification of fluid parameters, boundary conditions and geometry. This allows for the rapid assessment and analysis of different shapes and therefore the optimization of the component. Our framework is completely based on graphic processing units (GPUs), i.e., all computations are performed on the GPU avoiding costly memory transfers between graphic hardware and CPU memory. The computations are performed on a single desktop PC, thus the simulation results can reside in GPU memory and can directly be visualized. B-Spline curves are used for modelling the geometry and the user can interactively modify it by means of inserting and moving control points or applying local smooth deformations, with the corresponding rapid update of the discretization on the GPU. Computing one single time step is performed in fractions of a second, even if the fluid flow is modelled with about one million degrees of freedom. The fast geometric manipulation combined with the direct visualization of quantities like velocity or pressure field allows for an immediate feedback of shape or parameter changes. Although fast simulations do not yet achieve the high precision compared to conventional simulations, their results are suitable for analyzing trends.

Die Arbeit behandelt das Thema Skill-Management unter der Prämisse, dass für produzierende KMU theoretische Erkenntnisse operationalisierbar werden. Durch die Definition eines Skill-Management-Prozesses können die Skills von Mitarbeitern in einem Arbeitsprozess geplant und kontrolliert werden. Aus den beiden Anwendungsfeldern Personalplanung und Personalentwicklung bietet vor allem der Prozess der Personaleinsatzplanung Möglichkeiten, das Skill-Management in produzierenden KMU einzusetzen. Die Darstellung des Skill-Managements durch ein IT-System zeigt, dass vor allem Funktionen zur Berechnung von Zuordnungen von Mitarbeitern zu Aufgaben sowie Suchfunktionalitäten für semantische Suchen nach Experten als auch Schnittstellen zu anderen IT-Systemen benötigt werden. Durch die Speicherung der Skills von Mitarbeitern und betrieblichen Aufgaben in einer relationalen Datenbank, welche nach einer Skill- Klassifikation aufgebaut ist, wird der Zugriff auf Skill-Daten effizient.

IMOTRIS ist eine Webanwendung, die es Nutzern der logistischen Domäne erlaubt, intermodale Transportketten strategisch zu planen. Einerseits müssen für diese Aufgabe umfangreiche Daten gesammelt werden, andererseits müssen diese Daten als Wissen zur Verfügung stehen, damit die Algorithmen zur Komposition von Transportketten semantisch korrekte Aussagen treffen können. Die Bewegung des Semantic Web hat genau zu diesem Zweck in dem vergangenen Jahrzehnt eine Reihe von Standards, Konzepten und Werkzeugen hervorgebracht. Diese Diplomarbeit evaluiert Einsatzmöglichkeiten dieser Technologien in IMOTRIS und implementiert ausgewählte Anwendungsfälle. Es entsteht unter anderem ein Vokabular zur Beschreibung von logistischen Gütern und Dienstleistungen sowie eine darauf aufbauende Wissensbasis. Auf ihrer Grundlage werden Inferenzregeln für eine kontextabhängige Dienstleistungs- und Webserviceselektion implementiert.

Handels, H. (Ed.) et al.: Bildverarbeitung für die Medizin 2011 : Algorithmen, Systeme, Anwendungen. Berlin; Heidelberg; New York: Springer, 2011. (Informatik aktuell), pp. 309-313

Dual-Energy CT (DECT) ist seit einigen Jahren im klinischen Einsatz. Wir stellen eine Methode vor, wie mittels DECT die räumliche Verteilung der Knochendichte in Wirbeln bestimmt und für die Diagnose von Osteoporose verwendet werden kann. Des Weiteren beschreiben wir einen neuen Ansatz für die Bestimmung der Zusammensetzung des trabekulären Knochens. Unsere Methoden wurden erfolgreich an DECT-Daten von 29 Wirbeln getestet und bedeuten einen Informationsgewinn für den Bereich der Orthopädie.

Summers, Ronald M. (Ed.) et al.: Medical Imaging 2011: Computer-Aided Diagnosis. Part Two : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 12, No. 32. Bellingham: SPIE Press, 2011. (Proceedings of SPIE 7963), pp. 79633J-1 - 79633J-10

Dual-energy CT allows for a better material differentiation than conventional CT. For the purpose of osteoporosis diagnosis, a detection of regions with lowered bone mineral density (BMD) is of high clinical interest. Based on an existing biophysical model of the trabecular bone in vertebrae a new method for directly highlighting those low density regions in the image data has been developed. For this, we combine image data acquired at 80 kV and 140 kV with information about the BMD range in different vertebrae and derive a method for computing a color enhanced image which clearly indicates low density regions. An evaluation of our method which compares it with a quantitative method for BMD assessment shows a very good correspondence between both methods. The strength of our method lies in its simplicity and speed.

Ziel der Arbeit war der Entwurf eines Systems zur automatischen Erfassung des räumlichen Bewegungsverhaltens von Menschen sowie die semantische Auswertung der erfassten Daten. Dies wurde in Form einer vollständig funktionstüchtigen Demonstrationssoftware umgesetzt. Zudem wurde ein Konzept für eine intelligente, ortssensitive ToDo-List entwickelt und realisiert. Der erste Teil der Arbeit gibt einen Überblick über die nötigen Grundlagen, insbesondere Positionsbestimmungsverfahren, Location Based Services, die semantische Extraktion aus Geodaten, Taskmodelle und Clusterverfahren. Einen weiteren Schwerpunkt der Arbeit bildet die Entwicklung von Konzepten zur Erhebung von Positionsdaten mittels handelsüblicher Mobiltelefone, zu deren semantischer Auswertung inklusive Clustering sowie für einen Taskmanager. Dafür wurde ein Taskmodell erstellt und ein Scheduler entworfen. Im dritten Teil der Arbeit folgt dann zur Demonstration die praktische Umsetzung der entwickelten Konzepte unter Verwendung der Programmiersprache Java. Ein Resümee über die gewonnenen Erkenntnisse sowie ein Ausblick auf zukünftige Anwendungsmöglichkeiten schließen die Arbeit ab.

In dieser Literaturarbeit wird ein Überblick über die Ergebnisse der Literaturrecherche zum Thema Semantikextraktion aus Geodaten gegeben. Grundlegend wird hierzu zuerst der Stand der Technik zur Erhebung von Geodaten (Positionsbestimmung) dargestellt. Im Anschluss wird ein kurzer Überblick über die zur Verarbeitung notwendigen Datenschnittstellen aufgezeigt. Die semantische Extraktion der erhaltenen Geodaten, genauer die Profilierung mit Hilfe von Bewegungsprofilen und die Bestimmung von Georeferenzinformationen, wird im dritten Teil der Arbeit erläutert. Abschließend werden mögliche Anwendungsgebiete dieser Technik (namentlich Location Based Services) mit entsprechenden Beispielen vorgestellt.

The concept of "Ambient Assisted Living" (AAL) has become a relevant factor in the research landscape over the last couple of years. A multitude of national and international R&D projects is working on specific challenges and fields of application within the thematic area of AAL. However, the goal of a realization of the AAL vision is impeded by a number of obstacles and problems, for which this conference discusses possible resorts, approaches and recommendations within numerous papers. To confer these new approaches the AAL-Kongress 2011 brings together developers, producers, service providers, carriers and end user organisations working in the field of technologies and applications of Ambient Assisted Living (AAL).

IEEE Computer Society: 3DIMPVT 2011 : International Conference on 3D Imaging, Modeling, Processing, Visualization and Transmission. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, pp. 140-147

This paper focuses on the preparative process of retrieving accurate feature maps for a camera-based tracking system. With this system it is possible to create ready-touse Augmented Reality applications with a very easy setup work-flow, which in practice only involves three steps: filming the object or environment from various viewpoints, defining a transformation between the reconstructed map and the target coordinate frame based on a small number of 3D-3D correspondences and, finally, initiating a feature learning and Bundle Adjustment step. Technically, the solution comprises several sub-algorithms. Given the image sequence provided by the user, a feature map is initially reconstructed and incrementally extended using a Simultaneous-Localization-and-Mapping (SLAM) approach. For the automatic initialization of the SLAM module, a method for detecting the amount of translation is proposed. Since the initially reconstructed map is defined in an arbitrary coordinate system, we present a method for optimally aligning the feature map to the target coordinated frame of the augmentation models based on 3D-3D correspondences defined by the user. As an initial estimate we solve for a rigid transformation with scaling, known as Absolute Orientation. For refinement of the alignment we present a modification of the well-known Bundle Adjustment, where we include these 3D-3D-correspondences as constraints. Compared to ordinary Bundle Adjustment we show that this leads to significantly more accurate reconstructions, since map deformations due to systematic errors such as small camera calibration errors or outliers are well compensated. This again results in a better alignment of the augmentations during run-time of the application, even in large-scale environments.

Computers & Graphics, Vol.35 (2011), 4, pp. 778-788

This paper focuses on the preparative process of natural feature map retrieval for a mobile camera-based tracking system. We cover the most important aspects of a general purpose tracking system including the acquisition of the scene's geometry, tracking initialization and fast and accurate frame-by-frame tracking. To this end, several state-of-the-art techniques - each targeted at one particular subproblem - are fused together, whereby their interplay and complementary benefits form the core of the system and the thread of our discussion. The choice of the individual sub-algorithms in our system reflects the scarcity of computational resources on mobile devices. In order to allow a more accurate, more robust and faster tracking during run-time, we therefore transfer the computational load into the preparative customization step wherever possible. From the viewpoint of the user, the preparative stage is kept very simple. It only involves recording the scene from various viewpoints and defining a transformation into a target coordinate frame via manual definition of only a few 3D to 3D point correspondences. Technically, the image sequence is used to (1) capture the scene's geometry by a SLAM-Method and subsequent refinement via constrained Bundle Adjustment, (2) to train a Randomized-Trees classifier for wide-baseline tracking initialization, and (3) to analyze the view-point dependent visibility of each feature. During run-time, robustness and performance of the frame-to-frame tracking are further increased by fusing inertial measurements within a combined pose estimation.

Eine weit verbreitete Form des Lernens ist das Lernen mit Hilfe der Computertechnik. In Kombination mit den heute oft genutzten Instrumenten des Internets bieten sich immer wieder neue Chancen für die Bildung. Doch lassen sich diese auch mit einem gewissen Mehrwert für alle Beteiligten einsetzen? Die vorliegende Arbeit befasst sich mit der Erstellung eines Bildungskonzeptes, welches die Social Software Wiki und Blog in die berufliche Ausbildung von Mediengestaltern integriert. Dabei wird zuerst kurz auf das Web 2.0 eingegangen und Möglichkeiten der benannten Tools für einen sinnvollen Einsatz aufgezeigt. Durch eine ausführliche Analyse aller Rahmenbedingungen wird anschließend die Grundlage für das Bildungskonzept geschaffen. Unter Berücksichtigung der gewonnenen Ergebnisse wird daraufhin das Bildungsarrangement geplant und beschrieben. Die Arbeit zeigt, dass das Potential der Tools auch im berufsschulischen Alltag ausgeschöpft werden kann.

Loncaric, Sven (Ed.) et al.: ISPA 2011 : 7th International Symposium on Image and Signal Processing and Analysis. Zagreb: University of Zagreb, 2011, pp. 437-442

The number of available 3D models in various areas increases steadily. Efficient methods to search for 3D models by content, rather than textual annotations, are crucial. For this purpose, we propose content based 3D model retrieval using a compressive sensing technique which is very efficient in classification by using only few input information. Our approach to search and automatically return a set of 3D mesh models from a large database consists of three major steps: (1) suggestive contours extraction from different viewpoints to extract features of the query 3D model; (2) descriptor computation by analyzing the Histogram of Oriented Gradients of the suggestive contours in the space of diffusion tensor fields; and (3) compressive sensing based machine learning to retrieve the models and the most probable view-point. Experimental results show that our proposed 3D model retrieval system is very effective to retrieve the 3D models, even though there are variations of shape and pose of the models.

Bebis, George (Ed.) et al.: Advances in Visual Computing. 7th International Symposium, ISVC 2011 : Proceedings, Part II. Berlin, Heidelberg, New York: Springer, 2011. (Lecture Notes in Computer Science (LNCS) 6939), pp. 367-376

The number of available 3D models in various areas increases steadily. Efficient methods to search for 3D models by content, rather than textual annotations, are crucial. For this purpose, we propose a content based 3D model retrieval system using the Histogram of Orientation (HoO) from suggestive contours and their diffusion tensor fields. Our approach to search and automatically return a set of 3D mesh models from a large database consists of three major steps: (1) suggestive contours extraction from different viewpoints to extract features of the query 3D model; (2) HoO descriptor computation by analyzing the diffusion tensor fields of the suggestive contours; (3) similarity measurement to retrieve the models and the most probable view-point. Our proposed 3D model retrieval system is very efficient to retrieve the 3D models even though there are variations of shape and pose of the models. Experimental results are presented and indicate the effectiveness of our approach, competing with the current - more complicated - state of the art method and even improving results for several classes.

Electronics Letters, Vol.47 (2011), 21, pp. 1181-1183

A sketch-based 3D model retrieval methodology by using compressive sensing (CS) is presented. The approach to search and automatically return a set of 3D mesh models from a large database consists of histogram of oriented gradient feature extraction from projected images of 3D models, and CS based classification technique. Experimental results show that the proposed 3D model retrieval is very efficient to search for the 3D models from user-drawn sketches including the variation of shape, pose, and view-points.

IEEE Computer Society: International Joint Conference on Biometrics 2011 : IJCB 2011. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2011, 8 p.

Fuzzy commitment is an efficient template protection algorithm that can improve security and safeguard privacy of biometrics. Existing theoretical security analysis has proved that although privacy leakage is unavoidable, perfect security from information-theoretical points of view is possible when bits extracted from biometric features are uniformly and independently distributed. Unfortunately, this strict condition is difficult to fulfill in practice. In many applications, dependency of binary features is ignored and security is thus suspected to be highly overestimated. This paper gives a comprehensive analysis on security and privacy of fuzzy commitment regarding empirical evaluation. The criteria representing requirements in practical applications are investigated and measured quantitatively in an existing protection system for 3D face recognition. The evaluation results show that a very significant reduction of security and enlargement of privacy leakage occur due to the dependency of biometric features. This work shows that in practice, one has to explicitly measure the security and privacy instead of trusting results under non-realistic assumptions.

Bours, Patrick (Ed.): 3rd International Workshop on Security and Communication Networks. Proceedings : IWSCN 2011. Gjøvik: Gjøvik University College, 2011, pp. 67-74

Template protection is an important supplementary to biometric system for enhancing security and privacy protection. Its recognition and security performance is limited by inherent properties of the biometric modalities and the biometric systems used. Combining additional secret information such as PIN or password will be a promising way to improve the performance. The fuzzy vault is a widely-used cryptographic scheme to protect fingerprint minutiae. In this paper, we propose a novel method, which generates artificial minutiae from a PIN or password. A fused feature set including genuine and artificial minutiae is used to generate a protected template. The insertion of artificial minutiae increases the secret length as well as the robustness in the fuzzy vault. Our experimental results on the NIST SD 14 database show that both false match rate and false non-match rate are reduced in comparison with the original fuzzy vault method. Meanwhile, the crucial security factors such as the degree of the polynomial and the length of secret are enlarged. Additionally, the original method is vulnerable to linkage attacks. The proposed method improves the resistance against this attack.

Computer Graphics Forum, Vol.29 (2010), 3, pp. 913-922

Spatiotemporal data pose serious challenges to analysts in geographic and other domains. Owing to the complexity of the geospatial and temporal components, this kind of data cannot be analyzed by fully automatic methods but require the involvement of the human analyst's expertise. For a comprehensive analysis, the data need to be considered from two complementary perspectives: (1) as spatial distributions (situations) changing over time and (2) as profiles of local temporal variation distributed over space. In order to support the visual analysis of spatiotemporal data, we suggest a framework based on the "Self-Organizing Map" (SOM) method combined with a set of interactive visual tools supporting both analytic perspectives. SOM can be considered as a combination of clustering and dimensionality reduction. In the first perspective, SOM is applied to the spatial situations at different time moments or intervals. In the other perspective, SOM is applied to the local temporal evolution profiles. The integrated visual analytics environment includes interactive coordinated displays enabling various transformations of spatiotemporal data and post-processing of SOM results. The SOM matrix display offers an overview of the groupings of data objects and their two-dimensional arrangement by similarity. This view is linked to a cartographic map display, a time series graph, and a periodic pattern view. The linkage of these views supports the analysis of SOM results in both the spatial and temporal contexts. The variable SOM grid coloring serves as an instrument for linking the SOM with the corresponding items in the other displays. The framework has been validated on a large dataset with real city traffic data, where expected spatiotemporal patterns have been successfully uncovered. We also describe the use of the framework for discovery of previously unknown patterns in 41-years time series of 7 crime rate attributes in the states of the USA.

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2010. New York: IEEE, 2010, pp. 623-630

Automatic recovery of 3D human pose from monocular image sequences is a challenging and important research topic with numerous applications. Although current methods are able to recover 3D pose for a single person in controlled environments, they are severely challenged by realworld scenarios, such as crowded street scenes. To address this problem, we propose a three-stage process building on a number of recent advances. The first stage obtains an initial estimate of the 2D articulation and viewpoint of the person from single frames. The second stage allows early data association across frames based on tracking-by-detection. These two stages successfully accumulate the available 2D image evidence into robust estimates of 2D limb positions over short image sequences (= tracklets). The third and final stage uses those tracklet-based estimates as robust image observations to reliably recover 3D pose. We demonstrate state-of-the-art performance on the HumanEva II benchmark, and also show the applicability of our approach to articulated 3D tracking in realistic street conditions.

Institute of Electrical and Electronics Engineers (IEEE): IEEE/RSJ 2010 International Conference on Intelligent Robots and Systems. New York: The Institute of Electrical and Electronics Engineers (IEEE), 2010, pp. 1740-1747

Finding injured humans is one of the primary goals of any search and rescue operation. The aim of this paper is to address the task of automatically finding people lying on the ground in images taken from the on-board camera of an unmanned aerial vehicle (UAV). In this paper we evaluate various state-of-the-art visual people detection methods in the context of vision based victim detection from an UAV. The top performing approaches in this comparison are those that rely on flexible part-based representations and discriminatively trained part detectors. We discuss their strengths and weaknesses and demonstrate that by combining multiple models we can increase the reliability of the system. We also demonstrate that the detection performance can be substantially improved by integrating the height and pitch information provided by on-board sensors. Jointly these improvements allow us to significantly boost the detection performance over the current de-facto standard, which provides a substantial step towards making autonomous victim detection for UAVs practical.

ACM SIGGRAPH: Proceedings Web3D 2010 : 15th International Conference on 3D Web Technology. New York: ACM Press, 2010, pp. 185-193

We present a scalable architecture, which implements and further evolve the HTML/X3D integration model X3DOM introduced in [Behr et al. 2009]. The goal of this model is to integrate and update declarative X3D content directly in the HTML DOM tree. The model was previously presented in a very abstract and generic way by only suggesting implementation strategies. The available opensource x3dom.js architecture provides concrete solutions to the previously open points and extents the generic model if necessary. The outstanding feature of the architecture is to provide a single declarative interface to application developers and at the same time support of various backends through a powerful fallback-model. This fallback-model does not provide a single implementation strategy for the runtime and rendering module but supports different methods transparently. This includes native browser implementations and X3D-plugins as well as a WebGL-based scene-graph, which allows running the content without the need for installing additional plugins on all browsers that support WebGL. The paper furthermore discusses generic aspects of the architecture like encoding and introspection, but also provides details concerning two backends. It shows how the system interfaces with X3D-plugins and WebGL and also discusses implementation specific features and limitations.

Lalmas, Mounia (Ed.) et al.: Research and Advanced Technology for Digital Libraries : 14th European Conference ECDL. Proceedings. Berlin, Heidelberg, New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6273), pp. 352-363

Digital Library support for textual and certain types of non-textual documents has significantly advanced over the last years. While Digital Library support implies many aspects along the whole library workflow model, interactive and visual retrieval allowing effective query formulation and result presentation are important functions. Recently, new kinds of non-textual documents which merit Digital Library support, but yet cannot be accommodated by existing Digital Library technology, have come into focus. Scientific primary data, as produced for example, by scientific experimentation, earth observation, or simulation, is such a data type. We report on a concept and first implementation of Digital Library functionality, supporting visual retrieval and exploration in a specific important class of scientific primary data, namely, time-oriented data. The approach is developed in an interdisciplinary effort by experts from the library, natural sciences, and visual analytics communities. In addition to presenting the concept and discussing relevant challenges, we present results from a first implementation of our approach as applied on a real-world scientific primary data set.

Lalmas, Mounia (Ed.) et al.: Research and Advanced Technology for Digital Libraries : 14th European Conference ECDL. Proceedings. Berlin, Heidelberg, New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6273), pp. 376-383

The PROBADO project is a research effort to develop and operate advanced Digital Library support for non-textual documents. The main goal is to contribute to all parts of the Digital Library work flow from content acquisition over indexing to search and presentation. While not limited in terms of supported document types, reference support is developed for classical digital music and 3D architectural models. In this paper, we review the overall goals, approaches taken, and lessons learned so far in a highly integrated effort of university researchers and library experts. We address the problem of technology transfer, aspects of repository compilation, and the problem of inter-domain retrieval. The experiences are relevant for other project efforts in the non-textual Digital Library domain.

ACM SIGGRAPH: Proceedings Web3D 2010 : 15th International Conference on 3D Web Technology. New York: ACM Press, 2010, pp. 63-71

3D is useful in many real-world applications beyond computer games. The efficiency of communication is greatly enhanced by combining interlinked verbal descriptions with 3D content. However, there is a wide gap between the great demand for 3D content and the inconvenience and cost of delivering it. We propose using PDF, which is extremely well supported by standard content production workflows. Producing PDF with embedded 3D is currently not an easy task. As a solution to the problem we offer a freely available tool that makes embedding 3D in PDF documents an easy to use technology. Our solution is very flexible, extensible, and can be easily integrated with existing document workflow technology.

University of Ioannina: ITAB 2010 : 10th International Conference on Information Technology and Applications in Biomedicine. New York: IEEE, Inc., 2010, 5 p.

The accurate segmentation of liver vessels is an important step for further computer assisted analysis in oncologic planning tools. Multiscale based vessel enhancement methods are very famous and many papers about this topic were published. Vesselness filters proposed by Sato et al., Frangi et al. and Erdt et al. are based on eigenvalue analysis of the Hessian matrix. They were developed using completely different approaches, namely experimental, geometrical and analytical. In this paper, their behavior at junctions and nearby vessels is systematically compared and evaluated for the enhancement of the liver vasculature. We found that the filter function proposed by Frangi et al. has problems at junctions, while the ones developed by Sato et al and Erdt et al. have problems with nearby vessels. The latter are preferred for the task of liver vessel enhancement.

Dillon, Tharam et al.: Twenty-Third IEEE Symposium on Computer-Based Medical Systems : CBMS 2010. Los Alamitos, Calif.: IEEE Computer Society, 2010, pp. 249-254

We present a novel statistical shape model approach for fully automatic CT liver segmentation. Unlike previous techniques, our method combines learned local shape priors with constraints that are directly derived from the current curvature of the model in order to restrict adaptation to regions where large deformations are expected and observed. Our approach is based on a multi-tiered framework that is more robust against model initialization errors than existing methods, because the model's degrees of freedom are step-wise increased. We evaluated our method on a large data base of 86 CT liver scans from different vendors, protocols, varying resolution and contrast enhancement. For comparison, 50 of the scans were taken from 2 public data bases, one of it being the MICCAI'07 liver segmentation challenge data base. Evaluation shows state of the art results with an average mean surface distance between 1.3 mm and 1.85 mm compared to ground truth depending on the image resolution. With an average segmentation time of 45 seconds our approach outperforms other automatic methods.

ACM Transactions on Graphics, Vol.29 (2010), 4, pp. 95:1-95:6

View interpolation and image-based rendering algorithms often produce visual artifacts in regions where the 3D scene geometry is erroneous, uncertain, or incomplete. We introduce ambient point clouds constructed from colored pixels with uncertain depth, which help reduce these artifacts while providing non-photorealistic background coloring and emphasizing reconstructed 3D geometry. Ambient point clouds are created by randomly sampling colored points along the viewing rays associated with uncertain pixels. Our realtime rendering system combines these with more traditional rigid 3D point clouds and colored surface meshes obtained using multiview stereo. Our resulting system can handle larger-range view transitions with fewer visible artifacts than previous approaches.

IEEE Computer, Vol.43 (2010), 6, pp. 48-53

The literally billions of images available from online photo-sharing sites offer an unprecedented wealth of information but also add additional layers of complexity for reconstruction applications.

Institute for Systems and Technologies of Information, Control and Communication (INSTICC): VISIGRAPP 2010. Proceedings : International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications. INSTICC Press, 2010, pp. 60-67

The automatic extraction of foreground objects from the background is a well known problem. Much research has been done to solve the foreground/background segmentation with graph cuts. The major challenge is to determine the weights of the graph in order to obtain a good segmentation. In this paper we address this problem with a focus on the automatic segmentation of wood logs. We introduce a new solution to get information about foreground and background. This information is used to set the weights of the graph cut method. We compare four different methods to set these weights and show that the best results are obtained with our novel method, which is based on density estimation.

Computers & Graphics, Vol.34 (2010), 4, pp. 322-334; First published as article in Press 16 June 2010, DOI: 10.1016/j.cag.2010.05.007

The creation of building and facility models is a tedious and complicated task. Existing CAD models are typically not well suited since they contain too much or not enough detail; the manual modeling approach does not scale; different views on the same model are needed, and different levels of detail and abstraction; and finally, conventional modeling tools are inappropriate for models with many internal parameter dependencies. As a solution to this problem we propose a combination of a procedural approach with shape grammars. The model is created in a top-down manner; high-level changeability and re-usability are much less of a problem; and it can be interactively evaluated to provide different views at runtime. We present some insights on the relation between imperative and declarative grammar descriptions, and show a detailed case study with facility surveillance as a practical application.

Institute for Systems and Technologies of Information, Control and Communication (INSTICC): VISIGRAPP 2010. Proceedings : International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications. INSTICC Press, 2010, pp. 453-456

Magnetic Resonance Imaging (MRI), in spite of its potential in medical diagnosis, has one major drawback: Image acquisition is a slow process, requiring the patient to not move for several minutes. This renders MRI useless in a number of cases. In the case of MR Imaging of the Head, optical motion tracking can be used for motion compensation, thereby greatly improving image quality. In this paper, an MR-compatible approach of tracking the patient's head is presented which does not require his or her cooperation, based on stereo-optical marker tracking. It is adapted to work in the MRI scanner, does not influence the MR image acquisition and is easily integrated into clinical routine.

Institute for Systems and Technologies of Information, Control and Communication (INSTICC): VISIGRAPP 2010. Proceedings : International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications. INSTICC Press, 2010, pp. 302-309

The most challenging algorithmical task for markerless Augmented Reality applications is the robust estimation of the camera pose. With a given 3D model of a scene the camera pose can be estimated via model-based camera tracking without the need to manipulate the scene with fiducial markers. Up to now, the bottleneck of model-based camera tracking is the availability of such a 3D model. Recently time-of-flight cameras were developed which acquire depth images in real time. With a sensor fusion approach combining the color data of a 2D color camera and the 3D measurements of a time-of-flight camera we acquire a textured 3D model of a scene. We propose a semi-manual reconstruction step in which the alignment of several submeshes with a mesh processing tool is supervised by the user to ensure a correct alignment. The evaluation of our approach shows its applicability for reconstructing a 3D model which is suitable for model-based camera tracking even for objects which are difficult to measure reliably with a time-of-flight camera due to their demanding surface characteristics.

MIDAS Journal, (2010), 9 p.

The purpose of this paper is to present our extension of the MITK toolkit by a real-time navigation system for computer assisted surgery. The system was developed with laparoscopic partial nephrectomies as a first application scenario. The main goal of the application is to enable tracking of the tumor position and orientation during surgery. Our system is based on ultrasound to CT registration and electromagnetic tracking. The basic idea is to process tracking information to generate an augmented reality (AR) visualization of a tumor model in the camera image of a laparoscopic camera. Our system will enhance the surgeon's view on the current scene and therefore facilitates higher safety during the surgery. A key intention of the development was to use only open source toolkits such as VTK, MITK and OpenCV in order to implement the desired functionality. So far we have applied our system in vitro in two phantom trials with a surgeon which yielded promising results.

Brömme, Arslan (Ed.) et al.: BIOSIG 2010 : Proceedings of the Special Interest Group on Biometrics and Electronic Signatures. Bonn: Köllen, 2010. (GI-Edition - Lecture Notes in Informatics (LNI) P-164), pp. 45-56

Over the past decades, a number of methods have been reported in the scientific literature to protect the privacy of biometric information stored in biometric systems. Keyless Biometric Template Protection (KBTP) methods aim to protect biometric information without the use of long-term secrets by deploying one-way functions. These KBTP methods are currently developed to an extent that commercial products have become available. When assessing and comparing different KBTP methods it is important to have a common and generic approach. Therefore, in this paper we present a reference framework that can be used in assessing and comparing the privacy properties of KBTP systems.

Dawant, Benoit M. (Ed.) et al.: Medical Imaging 2010: Image Processing. Part One : Progress in Biomedical Optics and Imaging. Proceedings Issue. Vol. 11, No. 33. Bellingham: SPIE Press, 2010. (Proceedings of SPIE 7623), pp. 762352-1 - 762352-12

Prior knowledge can highly improve the accuracy of segmentation algorithms for 3D medical images. A popular method for describing the variability of shape of organs are statistical shape models. One of the greatest challenges in statistical shape modeling is to compute a representation of the training shapes as vectors of corresponding landmarks, which is required to train the model. Many algorithms for extracting such landmark vectors work on parameter space representations of the unnormalized training shapes. These algorithms are sensitive to inconsistent parameterizations: If corresponding regions in the training shapes are mapped to different areas of the parameter space, convergence time increases or the algorithms even fail to converge. In order to improve robustness and decrease convergence time, it is crucial that the training shapes are parameterized in a consistent manner. We present a novel algorithm for the construction of groupwise consistent parameterizations for a set of training shapes with genus-0 topology. Our algorithm firstly computes an area-preserving parameterization of a single reference shape, which is then propagated to all other shapes in the training set. As the parameter space propagation is controlled by approximate correspondences derived from a shape alignment algorithm, the resulting parameterizations are consistent. Additionally, the area-preservation property of the reference parameterization is likewise propagated such that all training shapes can be reconstructed from the generated parameterizations with a simple uniform sampling technique. Though our algorithm considers consistency as an additional constraint, it is faster than computing parameterizations for each training shape independently from scratch.

Erleben, Kenny (Ed.) et al.: VRIPHYS 10: 7th Workshop in Virtual Reality Interactions and Physical Simulations. Goslar: Eurographics Association, 2010, pp. 21-29

In the field of garment simulation the resolution of the simulation mesh has a direct impact on visual quality. Unfortunately, an increase in mesh resolution introduces a much higher computational cost and potentially causes instability inside the simulation. In addition, it increases the amount of data sent to the renderer for visualisation. Therefore, a GPU-based refinement of the simulated mesh has several advantages, since all additional data is generated immediately before rendering. This allows an increase in visual quality without adding to computational costs for the simulation process or bandwidth necessary for rendering. In this paper we present a view-dependent, adaptive tessellation method designed for the geometry processing stage of modern GPUs. It uses uniform meshes internally, removing the necessity to store external patches. Since we deal with a local refinement scheme, sudden changes in the mesh structure size on adjacent patches may occur incidentally. To reduce this effect as far as possible, we control the triangle density distribution of the refinement process inside a refined triangle patch.

IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol.32 (2010), 8, pp. 1392-1405

The efficient application of graph cuts to Markov Random Fields (MRFs) with multiple discrete or continuous labels remains an open question. In this paper, we demonstrate one possible way of achieving this by using graph cuts to combine pairs of suboptimal labelings or solutions. We call this combination process the fusion move. By employing recently developed graph-cut-based algorithms (so-called QPBO-graph cut), the fusion move can efficiently combine two proposal labelings in a theoretically sound way, which is in practice often globally optimal. We demonstrate that fusion moves generalize many previous graph-cut approaches, which allows them to be used as building blocks within a broader variety of optimization schemes than were considered before. In particular, we propose new optimization schemes for computer vision MRFs with applications to image restoration, stereo, and optical flow, among others. Within these schemes the fusion moves are used 1) for the parallelization of MRF optimization into several threads, 2) for fast MRF optimization by combining cheap-to-compute solutions, and 3) for the optimization of highly nonconvex continuous-labeled MRFs with 2D labels. Our final example is a nonvision MRF concerned with cartographic label placement, where fusion moves can be used to improve the performance of a standard inference method (loopy belief propagation).

Lampe, Bernhard P. (Ed.): 8th IFAC Conference on Control Applications in Marine Systems [online]. [cited 12 April 2011] Available from: http://www.ifac-papersonline.net/Control_Applications_in_Marine_Systems/8th_IFAC_Conference_on_Control_Applications_in_Marine_Systems__2010_/index.html 2010, 5 p.

The maritime sector with its wide spectrum of ancillary conditions can benefit from advanced computer graphics in many ways. The paper presents several applications from marketing over design to training and maintenance that are based on virtual or augmented reality technology. Some of the technical challenges that arise from the ambitious environment are sketched and an outlook on future research and development is given.

Huang, De-Shuang (Ed.) et al.: Advanced Intelligent Computing Theories and Applications : 6th International Conference on Intelligent Computing. Berlin, Heidelberg, New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6215), pp. 362-371

Adaptive User Interfaces are able to facilitate the handling of computer systems through the automatic adaptation to users' needs and preferences. For the realization of these systems, information about the individual user is needed. This user information can be extracted from user events by applying analytical methods without the active information input by the user. In this paper we introduce a reusable interaction analysis system based on probabilistic methods that predicts user interactions, recognizes user activities and detects user preferences on different levels of abstraction. The evaluation reveals that the prediction quality of the developed algorithm outperforms the quality of other established prediction methods.

Chen, Wen (Ed.) et al.: IEEE International Conference on Intelligent Computing and Intelligent Systems. Proceedings : ICIS 2010. New York: IEEE Press, 2010, pp. 607-612

Predictive statistical models are used in the area of adaptive user interfaces to model user behavior and to infer user information from interaction events in an implicit and non-intrusive way. This information constitutes the basis for tailoring the user interface to the needs of the individual user. Consequently, the user analysis process should model the user with information, which can be used in various systems to recognize user activities, intentions and roles to accomplish an adequate adaptation to the given user and his current task. In this paper we present the improved prediction algorithm KO*/19, which is able to recognize, beside interaction predictions, behavioral patterns for recognizing user activities. By means of this extension, the evaluation shows that the KO*/19-Algorithm improves the Mean Prediction Rank more than 19% compared to other well-established prediction algorithms.

Bartz, Dirk (Ed.) et al.: Eurographics Workshop on Visual Computing for Biology and Medicine : EG VCBM 2010. Goslar: Eurographics Association, 2010, pp. 75-82

Many inexact automatic tree matching algorithms are nowadays available. However, they provide matches that are not completely error free. Another option is to use manually matched node-pairs, but this enormously slows down the process. Our contribution to the state of the art is to combine the advantages of both solutions. We enhance the automatic tree matching algorithm designed by Graham et al., so that it is possible to interact with it by previously selecting important matches or by subsequently fixing the provided wrong matches. Thanks to this enhancement the speed of the algorithm is greatly increased. It takes 7.45 seconds for trees up to 192 nodes and less than 1 second if three input matches are provided. In addition to this an in-depth evaluation of the robustness of the algorithm is presented. The results are remarkable. The average of wrong matches varies between 1.17 and 1.4 node-pairs in the worst cases. The rate of correct matches is high.

Artusi, Alessandro (Ed.) et al.: VAST 2010. : Eurographics Symposium Proceedings. Goslar: Eurographics Association, 2010, pp. 105-114; 182 (Color plate)

This paper describes the design and the implementation of a distributed object repository that offers cultural heritage experts and practitioners a working platform to access, use, share and modify digital content. The principle of collecting paradata to document each step in a potentially long sequence of processing steps implies a number of design decisions for the data repository, which are described and explained. Furthermore, we provide a description of the concise API our implementation. Our intention is to provide an easy-to-understand recipe that may be valuable also for other data repository implementations that incorporate and operationalize the more theoretical concepts of intellectual transparency, collecting paradata, and compatibility to semantic networks.

The American Society of Mechanical Engineers (ASME): ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference : DETC 2010. New York: The American Society of Mechanical Engineers, 2010, 10 p.

The engineering design is a systematic approach implemented in the product development process, which is composed of several phases and supported by different tools. Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) tools are particularly dedicated to the embodiment phase and these enable engineers to design and analyze a potential solution. Nonetheless, the lack of integration between CAD and CAE restricts the exploration of design variations. Hence, we aim at incorporating functionalities of a CAD system within a CAE environment, by means of building a high level representation of the mesh and allowing the engineer to handle and manipulate semantic features, avoiding the direct manipulation of single elements. Thus, the engineer will be able to perform extruding, rounding or dragging operations regardless of geometrical and topological limitations. We present in this paper, the intelligence that a simulating mesh needs to support, in order to enable such operations.

Fabrikant, Sara Irina (Ed.) et al.: Geographic Information Science. Berlin; Heidelberg; New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6292), pp. 204-218

Geospatial data offered by distributed services are often modelled with different conceptual schemas although they cover the same thematic area. To ensure interoperability of geospatial data, the existing heterogeneous conceptual schemas can be mapped to a common conceptual schema. However, the underlying formalized schema mappings are difficult to create, difficult to re-use and often contain mismatches of abstraction level, of scope difference, domain semantics and value semantics of the mapped entities. We have developed a novel approach to document and communicate such mismatches in the form of a Mismatch Description Language (MDL). This MDL can be transformed into various textual and cartographic representations to support users in communicating and understanding mismatches, and to assess the reusability of a mapping.

Artusi, Alessandro (Ed.) et al.: VAST 2010. : Eurographics Symposium Proceedings. Goslar: Eurographics Association, 2010, pp. 1-8; 179 (Color plate)

We present a novel 3D geometry acquisition technique at high resolution based on structured light reconstruction with a low-cost projector-camera system. Using a 1D mechanical lens-shifter extension in the projector light path, the projected pattern is shifted in fine steps at sub-pixel scale with a granularity of down to 2048 steps per projected pixel, which opens up novel possibilities in depth accuracy and smoothness for the acquired geometry. Combining the mechanical lens-shifter extension with a multiple phase shifting technique yields a measuring range of 120x80 mm while at the same time providing a high depth resolution of better than 100 micron. Reaching far beyond depth resolutions achieved by conventional structured light scanning approaches with projector-camera systems, depth layering effects inherent to conventional techniques are fully avoided. Relying on low-cost consumer products only, we reach an area resolution of down to 55 micron (limited by the camera). We see two fields of benefit. Firstly, our acquisition setup can reconstruct finest details of small Cultural Heritage objects such as antique coins and thus digitally preserve them in appropriate precision. Secondly, our accurate height fields can be viable input to physically based rendering in combination with measured material BRDFs to reproduce compelling spatially varying, material-specific effects.

8th IEEE International Conference on Pervasive Computing and Communications (PERCOM Workshops). New York: IEEE Press, 2010, pp. 286-291

This paper describes a new embedded system, called iFall, for the detection of unexpected falls for elderly people. In combination with a new sensors system and the monitoring of its own rotation, iFall is able to detect a fall in its very beginning. It is thus able to initiate some emergency actions, such as inflating a tiny airbag, in order to alleviate a fall's consequences, primarily potential injuries. In that respect, iFall is unique. It's physical properties, such as size, weight, and energy resources, make it almost invisible, so that it can be worn at any time at any occasion by any person.

Ioannides, Marinos (Ed.) et al.: Digital Heritage. Third International Conference, EuroMed 2010. Berlin, Heidelberg, New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6436), pp. 153-165

Within the last few years generative modeling techniques have gained attention especially in the context of cultural heritage. As a generative model describes a rather ideal object than a real one, generative techniques are a basis for object description and classification. This procedural knowledge differs from other kinds of knowledge, such as declarative knowledge, in a significant way. It can be applied to a task. This similarity to algorithms is reflected in the way generative models are designed: they are programmed. In order to make generative modeling accessible to cultural heritage experts, we created a generative modeling framework which accounts for their special needs. The result is a generative modeler (http://www.cgv.tugraz.at/euclides) based on an easy-to-use scripting language (JavaScript). The generative model meets the demands on documentation standards and fulfils sustainability conditions. Its integrated meta-modeler approach makes it independent from hardware, software and platforms

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2010. New York: IEEE, 2010, 8 p.

Markov random fields (MRFs) are popular and generic probabilistic models of prior knowledge in low-level vision. Yet their generative properties are rarely examined, while application-specific models and non-probabilistic learning are gaining increased attention. In this paper we revisit the generative aspects of MRFs, and analyze the quality of common image priors in a fully application-neutral setting. Enabled by a general class of MRFs with flexible potentials and an efficient Gibbs sampler, we find that common models do not capture the statistics of natural images well. We show how to remedy this by exploiting the efficient sampler for learning better generative MRFs based on flexible potentials. We perform image restoration with these models by computing the Bayesian minimum mean squared error estimate (MMSE) using sampling. This addresses a number of shortcomings that have limited generative MRFs so far, and leads to substantially improved performance over maximum a-posteriori (MAP) estimation. We demonstrate that combining our learned generative models with sampling-based MMSE estimation yields excellent application results that can compete with recent discriminative methods.

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2010. New York: IEEE, 2010, 8 p.

Object recognition is challenging due to high intra-class variability caused, e.g., by articulation, viewpoint changes, and partial occlusion. Successful methods need to strike a balance between being flexible enough to model such variation and discriminative enough to detect objects in cluttered, real world scenes. Motivated by these challenges we propose a latent conditional random field (CRF) based on a flexible assembly of parts. By modeling part labels as hidden nodes and developing an EM algorithm for learning from class labels alone, this new approach enables the automatic discovery of semantically meaningful object part representations. To increase the flexibility and expressiveness of the model, we learn the pairwise structure of the underlying graphical model at the level of object part interactions. Efficient gradient-based techniques are used to estimate the structure of the domain of interest and carried forward to the multi-label or object part case. Our experiments illustrate the meaningfulness of the discovered parts and demonstrate state-of-the-art performance of the approach.

Matsopoulos, George K. (Ed.): Self-Organizing Maps [online]. [cited 17 January 2012] Available from: http://www.intechopen.com/books/show/title/self-organizing-maps Intech, 2010, pp. 83-96

Based on the Self-Organizing Map (SOM) algorithm, development of effective solutions for visual analysis and retrieval in complex data is possible. Example application domains include retrieval in multimedia data bases, and analysis in financial, text, and general high-dimensional data sets. While early work defined basic concepts for data representation and visual mappings for SOM-based analysis, recent work contributed advanced visual representations of the output of the SOM algorithm, and explored innovative application concepts. In this article, we review a selection of classic and more recent approaches to SOM-based visual analysis. We argue that important improvements have been achieved which allow effective visual representation and interaction with the output of the SOM algorithm. We identify promising directions for future research, which will support new application areas and provide additional advanced visualization approaches.

Lensch, Hendrik P. A. (Ed.) et al.: Eurographics 2010. Short Papers, pp. 49-52

Spectral rendering takes the full visible spectrum into account when calculating light-surface interaction and can overcome the well-known deficiencies of rendering with tristimulus color models. We present a variant of the precomputed radiance transfer algorithm that is tailored towards real-time spectral rendering on modern graphics hardware. Our method renders diffuse, self-shadowing objects with spatially varying spectral reflectance properties under distant, dynamic, full-spectral illumination. To achieve real-time frame rates and practical memory requirements we split the light transfer function into an achromatic part that varies per vertex and a wavelength-dependent part that represents a spectral albedo texture map. As an additional optimization, we project reflectance and illuminant spectra into an orthonormal basis. One area of application for our research is virtual design applications that require relighting objects with high color fidelity at interactive frame rates.

Institute for Systems and Technologies of Information, Control and Communication (INSTICC): VISIGRAPP 2010. Proceedings : International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications. INSTICC Press, 2010, pp. 165-172

Spectral rendering takes the full visible spectrum into account when calculating light-surface interaction and can overcome the well-known deficiencies of rendering with tristimulus color models. In this paper we show how to represent wavelength-dependent BRDFs as factored tensors. We use this representation for realtime spectral rendering on modern graphics hardware. Strong data compression and fast rendering times are achieved for mostly diffuse and moderately glossy isotropic surfaces. The method can handle high-resolution tabulated BRDFs, including non-reciprocal ones, which makes it well-suited for measured data. We analyze our approach numerically and visually. One area of application for our research is virtual design applications that require high color fidelity at interactive frame rates.

Journal of Computational Biology [online], Vol.17 (2010), 4, pp. 603-615

Emerging DNA sequencing technologies open up exciting new opportunities for genome sequencing by generating read data with a massive throughput. However, produced reads are significantly shorter and more error-prone compared to the traditional Sanger shotgun sequencing method. This poses challenges for de novo DNA fragment assembly algorithms in terms of both accuracy (to deal with short, error-prone reads) and scalability (to deal with very large input data sets). In this article, we present a scalable parallel algorithm for correcting sequencing errors in high-throughput short-read data so that error-free reads can be available before DNA fragment assembly, which is of high importance to many graph-based short-read assembly tools. The algorithm is based on spectral alignment and uses the Compute Unified Device Architecture (CUDA) programming model. To gain efficiency we are taking advantage of the CUDA texture memory using a space-efficient Bloom filter data structure for spectrum membership queries. We have tested the runtime and accuracy of our algorithm using real and simulated Illumina data for different read lengths, error rates, input sizes, and algorithmic parameters. Using a CUDA-enabled mass-produced GPU (available for less than US$400 at any local computer outlet), this results in speedups of 12-84 times for the parallelized error correction, and speedups of 3-63 times for both sequential preprocessing and parallelized error correction compared to the publicly available Euler-SR program. Our implementation is freely available for download from http:// cuda-ec.sourceforge.net.

Proceedings of the IEEE, Vol.98 (2010), 8, pp. 1370-1390

There are billions of photographs on the Internet, representing an extremely large, rich, and nearly comprehensive visual record of virtually every famous place on Earth. Unfortunately, these massive community photo collections are almost completely unstructured, making it very difficult to use them for applications such as the virtual exploration of our world. Over the past several years, advances in computer vision have made it possible to automatically reconstruct 3D geometry-including camera positions and scene models-from these large, diverse photo collections. Once the geometry is known, we can recover higherlevel information from the spatial distribution of photos, such as the most common viewpoints and paths through the scene. This article reviews recent progress on these challenging computer vision problems, and describes how we can use the recovered structure to turn community photo collections into immersive, interactive 3D experiences.

University of Ioannina: ITAB 2010 : 10th International Conference on Information Technology and Applications in Biomedicine. New York: IEEE, Inc., 2010, 4 p.

One major challenge in automated segmentation of lymph nodes in CT scans is the high variance in terms of texture, surrounding tissue, shape and also size. Mass Spring Models have been proven to be suitable for this task. However due to their size preserving property, their performance is highly affected by the size of the target structures. This paper addresses this point by introducing a size invariant Mass Spring Model, which relates to relative rest lengths, has balanced torsion forces and an initial model expansion. We evaluated our method on a set of 25 lymph nodes from routinely gathered CT images and compared it to state of the art Mass Spring Models with different initial sizes. The average Dice Similarity Coefficient toward gold standard was 0.72 for our method compared to 0.61 for the best fitted state of the art model. Thus our method can be successfully applied to clinical relevant lymph nodes of different size without prior knowledge about the size of the target structures in contrast to existing methods

University of Ioannina: ITAB 2010 : 10th International Conference on Information Technology and Applications in Biomedicine. New York: IEEE, Inc., 2010, 5 p.

Maximization of a voxel based similarity metric like mutual information is the state of the art for the multimodal rigid registration of the head. To achieve satisfactory results the transform needs to be initialized properly and the region of interest (ROI) containing only rigid structures has to be defined in both images. In this paper we present and comprehensively evaluate an automated initialization and ROI detection method that enables the fully automated rigid registration of routinely gathered head CT and MR images. For ROI definition an automated head detection heuristic is presented that is robust against truncation and can be applied to images of different modalities. The registration transform is initialized based on a novel automated landmark detection method. Combined with standard mutual information based registration techniques, this result in a fully automated rigid registration framework for truncated CT/MR head & neck images. We evaluated the landmark detection in 81 routinely gathered truncated MR and CT images of the head & neck. Those images form 57 intra subject CT/MR pairs to which the overall approach was applied and evaluated by visual inspection. We show that the presented approach is robust against truncation and influence of non rigid structures. Not requiring any user interaction at all, it enables new applications in clinical practice.

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2010. New York: IEEE, 2010, 8 p.

The accuracy of optical flow estimation algorithms has been improving steadily as evidenced by results on the Middlebury optical flow benchmark. The typical formulation, however, has changed little since the work of Horn and Schunck. We attempt to uncover what has made recent advances possible through a thorough analysis of how the objective function, the optimization method, and modern implementation practices influence accuracy. We discover that "classical" flow formulations perform surprisingly well when combined with modern optimization and implementation techniques. Moreover, we find that while median filtering of intermediate flow fields during optimization is a key to recent performance gains, it leads to higher energy solutions. To understand the principles behind this phenomenon, we derive a new objective that formalizes the median filtering heuristic. This objective includes a non-local term that robustly integrates flow estimates over large spatial neighborhoods. By modifying this new term to include information about flow and image boundaries we develop a method that ranks at the top of the Middlebury benchmark.

Ruyter, Boris de (Ed.) et al.: Ambient Intelligence : AmI 2010. Berlin; Heidelberg; New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6439), pp. 227-238

Challenges of handling user interaction in Ambient Intelligence environments are manifold. The systems installed in these environments are highly distributed with dynamic configurations in terms of integrated devices and installed applications. Context-awareness, personalization, and multimodality are critical for supporting more natural interaction and optimizing the interaction in an adaptive way. Research activities have dealt with different specific problems in the field and now it is high time for moving towards an open framework with a more comprehensive solution. This paper introduces results of such work with a high level of freedom in developing and deploying applications without needing to care about the available I/O infrastructure. The other way around, the latter can be changed without worrying about the application side. The independence of applications from the available I/O infrastructure helps to share mechanisms and manage such a complex scene more adequately. The key idea behind this framework is the natural distribution of tasks according to the real scene using a middleware solution supporting seamless connectivity and goal-based interoperability.

Institute for Systems and Technologies of Information, Control and Communication (INSTICC): VISIGRAPP 2010. Proceedings : International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications. INSTICC Press, 2010, pp. 65-71

In this work we introduce an approach for reconstructing digital 3D models from multiple perspective line drawings. One major goal is to keep the required user interaction simple and at a minimum, while making no constraints to the objects shape. Such a system provides a useful extension for digitalization of paper-based styling concepts, which today is still a time consuming process. In the presented method the line drawings are first decomposed in curves assembling a network of curves. In a second step, the positions for the endpoints of the curves are determined in 3D, using multiple sketches and a virtual camera model given by the user. Then the shapes of the 3D curves between the reconstructed 3D endpoints are inferred. This leads to a network of 3D curves, which can be used for first visual evaluations in 3D. During the whole process only little user interaction is needed, which only takes place in the pre- and post-processing phases. The approach has been applied on multiple sketches and it is shown that the approach creates plausible results within reasonable timing.

Daniilidis, Kostas (Ed.) et al.: Computer Vision - ECCV 2010. Proceedings, Part IV : 11th European Conference on Computer Vision. Berlin, Heidelberg, New York: Springer, 2010. (Lecture Notes in Computer Science (LNCS) 6314), pp. 467-481

Scene understanding has (again) become a focus of computer vision research, leveraging advances in detection, context modeling, and tracking. In this paper, we present a novel probabilistic 3D scene model that encompasses multi-class object detection, object tracking, scene labeling, and 3D geometric relations. This integrated 3D model is able to represent complex interactions like inter-object occlusion, physical exclusion between objects, and geometric context. Inference allows recovering 3D scene context and performing 3D multiobject tracking from a mobile observer, for objects of multiple categories, using only monocular video as input. In particular, we show that a joint scene tracklet model for the evidence collected over multiple frames substantially improves performance. The approach is evaluated for two different types of challenging onboard sequences. We first show a substantial improvement to the state-of-the-art in 3D multi-people tracking. Moreover, a similar performance gain is achieved for multi-class 3D tracking of cars and trucks on a new, challenging dataset.

ACM SIGMM: Proceedings of the ACM Multimedia 2010 International Conference : MM'10. New York: ACM, 2010, pp. 193-200

The number of available 3D models in various areas increases steadily. Effective methods to search for those 3D models by content, rather than textual annotations are crucial. For this purpose, we propose a new approach for content based 3D model retrieval by hand-drawn sketch images. This approach to retrieve visually similar mesh models from a large database consists of three major steps: (1) suggestive contour renderings from different viewpoints to compare against the user drawn sketches; (2) descriptor computation by analyzing diffusion tensor fields of suggestive contour images, or the query sketch respectively; (3) similarity measurement to retrieve the models and the most probable view-point from which a model was sketched. Our proposed sketch based 3D model retrieval system is very robust against variations of shape, pose or partial occlusion of the user drawn sketches. Experimental results are presented and indicate the effectiveness of our approach for sketch-based 3D model retrieval.

Memon, Nasir D. (Ed.) et al.: Media Forensics and Security II. Bellingham: SPIE Press, 2010. (Proceedings of SPIE 7541), pp. 75410Q-1 - 75410Q-8

Biohashing algorithms map biometric features randomly onto binary strings with user-specific tokenized random numbers. In order to protect biometric data, these binary strings, the Biohashes, are not allowed to reveal much information about the original biometric features. In the paper we analyse two Biohashing algorithms using scalar randomization and random projection respectively. With scalar randomization, multiple bits can be extracted from a single element in a feature vector. The average information rate of Biohashes is about 0.72. However, Biohashes expose the statistic information about biometric feature, which can be used to estimate the original feature. Using random projection method, a feature vector in n dimensional space can be converted into binary strings with length of m (m <= n). Any feature vector can be converted into 2m different Biohashes. The random projection can roughly preserve Hamming distance between Biohashes. Moreover, the direction information about the original vector can be retrieved with Biohashes and the corresponding random vectors used in the projection. Although Biohashing can efficiently randomize biometric features, combining more Biohashes of the same user can leak essential information about the original feature.

Guralnick, David (Ed.): ICELW 2009 Proceedings CD-ROM : The International Conference on E-Learning in the Workplace, 5 p.

Learning is a by-product of working when a problem, question or curiosity occurs during everyday work processes. Thereby interpersonal help seeking is a commonly used learning strategy to acquire missing knowledge. Although the help requesting party benefits from other's help, helping people are interrupted in ongoing work processes. This correlation of work-integrated learning and unplanned interruptions can be addressed by providing support for interpersonal help seeking. Based on a generalized model of contextualized knowledge transfer, three different approaches are introduced to support the learning without interrupting others.

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2009. New York: IEEE, 2009, pp. 1014-1021

Non-rigid object detection and articulated pose estimation are two related and challenging problems in computer vision. Numerous models have been proposed over the years and often address different special cases, such as pedestrian detection or upper body pose estimation in TV footage. This paper shows that such specialization may not be necessary, and proposes a generic approach based on the pictorial structures framework. We show that the right selection of components for both appearance and spatial modeling is crucial for general applicability and overall performance of the model. The appearance of body parts is modeled using densely sampled shape context descriptors and discriminatively trained AdaBoost classifiers. Furthermore, we interpret the normalized margin of each classifier as likelihood in a generative model. Non-Gaussian relationships between parts are represented as Gaussians in the coordinate system of the joint between parts. The marginal posterior of each part is inferred using belief propagation. We demonstrate that such a model is equally suitable for both detection and pose estimation tasks, outperforming the state of the art on three recently proposed datasets.

Fellner, Dieter W. (General Co-Chair) et al.: Proceedings Web3D 2009 : 14th International Conference on 3D Web Technology. New York: ACM Press, 2009, pp. 127-135

We present a model that allows to directly integrate X3D nodes into HTML5 DOM content. This model tries to fulfill the promise of the HTML5 specification, which references X3D for declarative 3D scenes but does not define a specific integration mode. The goal of this model is to ease the integration of X3D in modern web applications by directly mapping and synchronizing live DOM elements to a X3D scene model. This is a very similar approach to the current SVG integration model for 2D graphics. Furthermore, we propose a framework that includes a new X3D Profile for the DOM integration. This profile should make implementation simple, but in addition we show that the current X3D runtime model still scales well. A detailed discussion includes DOM integration issues like events, namespaces and scripting. We finally propose an implementation framework that should work with multiple browser frontends (e.g. Firefox andWebKit) and different X3D runtime backends. We hope to connect the technologies and the X3D/ W3C communities with this proposal and outline a model, how an integration without plugins could work. Moreover, we hope to inspire further work, which could lead to a native X3D implementation in browsers similar to the SVG implementations today.

Grimm, Cindy (Ed.) et al.: ACM SIGGRAPH / Eurographics Symposium on Sketch-Based Interfaces and Modeling 2009. Proceedings. New York: ACM, 2009, pp. 61-68

We describe a 3D modeling system that combines subdivision surfaces with sketch-based modeling in order to meet two conflicting goals: ease of use and fine-grained shape control. For the excellent control, low-poly modeling is still the method of choice for creating high-quality 3D models, e.g., in the games industry. However, direct mesh editing can be very tedious and time consuming. Our idea is to include also stroke-based techniques for rapidly modeling regular surface parts. We propose a simple and efficient algorithm for converting a 2D stroke to a control polygon suitable for Catmull/Clark subdivision surfaces. We have realized a small but reasonably rich set of interactive modeling tools to assess the expressiveness of stroke-based mesh design with a number of examples.

Fellner, Dieter W. (General Co-Chair) et al.: Proceedings Web3D 2009 : 14th International Conference on 3D Web Technology. New York: ACM Press, 2009, pp. 111-118

We present a framework for formulating domain-dependent 3D search queries suitable for content-based 3D search over the web. Users are typically not willing to spend much time to create a 3D query object. They expect to quickly see a result set in which they can navigate by further differentiating the query object. Our system innovates by using a streamlined parametric 3D modeling engine on both client and server side. Parametric tools have greater expressiveness, they allow shape manipulation through a few highlevel parameters, as well as incremental assembly of query objects. Short command strings are sent from client to server to keep the query objects on both sides in sync. This reduces turnaround times and allows asynchronous updates of live result sets.

Association for Computing Machinery (ACM): Proceedings of the 2nd ACM International Conference on PErvasive Technologies Related to Assistive Environments : PETRA 2009 [CD-ROM]. New York: ACM, 2009, 6 p.

Patient monitoring by camera surveillance within the private surrounding suffers on privacy issues as well as high requirements on sensor technology and infrastructure. Because of those limitations there is not much knowledge on user activities and behavior in the home environment. In this paper we introduce a novel concept of local activity monitoring using a very slim infrastructure. The required technical environment consists only of a Wi-Fi-Webcam and a mobile phone. With a bi-modal sensor fusion approach we improve the optical activity monitoring by inclusion of electromechanical movement sensors data taken from a mobile phone. The fusion of data from cameras and mobile acceleration sensors allow for a comprehensive, non obtrusive observation of people which can be used for behavior analysis, reactive assistance and support, and natural interfaces especially for the elderly.

HCI International 2009. Proceedings and Posters [DVD-ROM] : With 10 further Associated Conferences. Berlin, Heidelberg, New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS)), LNCS 5615, pp. 289-296

Mobile applications for activity monitoring are regarded as a high potential field for efficient improvement of health care solutions. The measurement of physical activity within every-day conditions should be as easy as using an automatic weighing machine. Up to now physical activity monitoring required special sensor devices and are not suitable for an every day usage. Movement pattern recognition based on acceleration data enables the usage of standard mobile phones for measurement of physical activity. Now, just by carrying a standard phone in a pocket, the device provides information about the type, intensity and duration of the performed activity. Within the project DiaTrace, we developed the method and algorithm to detect activities like walking, jumping, running, cycling or car driving. Based on activity measurement, this application also calculates the consumed calories over the day, shares activity progress with friends or family and might deliver details about different kinds of transportation during a business trip. The DiaTrace application can easily used today by standard phones which are already equipped with the required sensors.

Shi, Riyi (Ed.) et al.: Proceedings of the 2009 2nd International Conference on Biomedical Engineering and Informatics. New York: IEEE, Inc., 2009, 5 p.

Extracting hepatic vasculature from three dimensional imagery is important for diagnosis of liver disease and planning of liver surgery. In this paper we propose a method for generation of 3D skeletal graph of liver vessels using thinning algorithm and graph theory. First of all, basic methodology in the proposed method is introduced. Secondly, the skeletonization method together with a pre-processing method on liver vessel images is employed to form liver skeleton image. Thirdly, a graphbased technique is then employed on the skeleton result to efficiently form the hepatic vessel system. The liver vessel tree generation method was evaluated on liver CT datasets to show its effectiveness and efficiency.

Brömme, Arslan (Ed.) et al.: BIOSIG 2009 : Proceedings of the Special Interest Group on Biometrics and Electronic Signatures. Bonn: Gesellschaft für Informatik, 2009. (GI-Edition - Lecture Notes in Informatics (LNI) P-155), pp. 69-80

Travel documents such as the electronic passport (ePass) ensure that each person can be uniquely identified by a single document. The development of new ePass security chip technologies allows for the inclusion of biometrie properties in the data carrier of the ePass. The International Civil Aviation Organization (ICAO) has determined a personal photograph as being the interoperable feature for all global travel documents; ICAO [Gro04] regulations reference quality requirements for facial images as defined in ISO standard ISOIIEC 19794-5 [Intb]. Project FIReBIRDs goal is to prepare an international facial image database for conformity tests based on ISOIIEC 19794-5 [Intb], to analyze the requirements in the regulating documents, and to develop suggestions for adaptations and extensions of these standards. The FIReBIRD database shall provide a well-defined ground truth for level 3 conformance testing. For this purpose the specifications in the standard were thoroughly analyzed and in some parts refined to allow for apreeise definition of ground truth. We show with two examples that there might be a defined common-sense definition for some parameters, but they are not measurable and their specification is not scientifically founded: the definition of full frontal view and the definition of eye and hair colors. Our results show that specifications and requirements should always be checked for necessity, practicability and usability and that a continued review and revision of biometric standards is necessary.

Rendiconti di matematica e delle sue applicazioni, Vol.29 (2009), 1, pp. 65-81

Cellular networks are ubiquitous in nature. They exhibit behavior on many different length and time scales and are generally metastable. Most technologically useful materials are polycrystalline microstructures composed of a myriad of small monocrystalline grains separated by grain boundaries. The energetics and connectivity of the grain boundary network plays a crucial role in determining the properties of a material across a wide range of scales. A central problem in materials science is to develop technologies capable of producing an arrangement of grains - a texture - that provides for a desired set of material properties. Here we discuss briefly the role of energy in texture development, measured by a character distribution, and how this is different from the evolution of geometric features, which we term geometric coarsening. For this purpose we present a critical event model to deepen our understanding of the topological reconfigurations that occur during the growth process.

Magnenat-Thalmann, Nadia (Ed.): Modelling the Physiological Human : 3D Physiological Human Workshop. Proceedings. Berlin, Heidelberg, New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS) 5903), pp. 25-35

Statistical Shape Models have been proven to be valuable tools for segmenting anatomical structures of arbitrary topology. Being based on the statistical description of representative shapes, an initial segmentation is required - preferably done by an expert. For this purpose, mostly manual segmentation methods followed by a mesh generation step are employed. A prerequisite for generating the training data based on these segmentations is the establishment of correspondences between all training meshes. While existing approaches decouple the expert segmentation from the correspondence establishment step, we propose in this work a segmentation approach that simultaneously establishes the landmark correspondences needed for the subsequent generation of shape models. Our approach uses a reference segmentation given as a regular mesh. After an initial placement of this reference mesh, it is manually deformed in order to best match the boundaries of the considered anatomical structure. This deformation is coupled with a real time optimization that preserves point correspondences and thus ensures that a pair of landmark points in two different data sets represents the same anatomical feature. We applied our new method to different anatomical structures: vertebra of the spinal chord, kidney, and cardiac left ventricle. In order to perform a visual evaluation of the degree of correspondence between different data sets, we have developed well adapted visualization methods. From our tests we conclude that the expected correspondences are established during the manual mesh deformation. Furthermore, our approach considerably speeds up the shape model generation, since there is no need for an independent correspondence establishment step. Finally, it allows the creation of shape models of arbitrary topology and removes potential error sources of landmark and correspondence optimization algorithms needed so far.

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2009. New York: IEEE, 2009, pp. 627-634

We present an approach for recovering the reflectance of a static scene with known geometry from a collection of images taken under distant, unknown illumination. In contrast to previous work, we allow the illumination to vary between the images, which greatly increases the applicability of the approach. Using an all-frequency relighting framework based on wavelets, we are able to simultaneously estimate the per-image incident illumination and the persurface point reflectance. The wavelet framework allows for incorporating various reflection models. We demonstrate the quality of our results for synthetic test cases as well as for several datasets captured under laboratory conditions. Combined with multi-view stereo reconstruction, we are even able to recover the geometry and reflectance of a scene solely using images collected from the Internet.

Buntine, Wray (Ed.) et al.: Machine Learning and Knowledge Discovery in Databases : European Conference, ECML PKDD 2009. Proceedings, Part I. Berlin, Heidelberg, New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS) 5781), pp. 517-532

This article contributes a generic model of topic models. To define the problem space, general characteristics for this class of models are derived, which give rise to a representation of topic models as "mixture networks", a domainspecific compact alternative to Bayesian networks. Besides illustrating the interconnection of mixtures in topic models, the benefit of this representation is ist straight-forward mapping to inference equations and algorithms, which is shown with the derivation and implementation of a generic Gibbs sampling algorithm.

Latoschik, Marc Erich (Ed.) et al.: 2nd Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS@VR2009) : IEEE Virtual Reality 2009 Workshop. Aachen: Shaker, 2009, pp. 41-50

In this paper we describe an X3D-based framework for simplifying the integration of virtual characters into dialog-based VR systems, by introducing another level of abstaction on top of X3D by means of a higher level language, which can be used for module communication and for coordinating the conversational behaviour of virtual humans. Therefore, we propose an self-contained and integrated system with matching techniques and building blocks that not only provides flexible control of the character, but also considers resultant dependencies, which need to be simulated during runtime. Furthermore, our system also takes physiological processes into account, which is essential for the correct perception of some emotions in the context of nonverbal communication. Thus, our proposed approach offers more efficiency by means of the integration into more abstact system architectures, into well established visualization techniques like the scene-graph, and into existing open standards.

IEEE Signal Processing Society (SPS): 6th IEEE International Symposium on Biomedical Imaging: From Nano to Macro : ISBI 2009. New York: IEEE Press, 2009, pp. 967-970

Ultrasound and computed tomography registration is a valuable tool for interventional imaging and navigation, but current methods are limited in reliability or usefulness, requiring large fields of view, large ultrasound penetration depth, distinct image features, or contours of the investigated organs. Computationally cheap, small-field- of-view registration proved elusive so far. We propose the use of interventional ultrasound elastography imaging to perform limited-field-of-view, limited-features registration reliably, examining the image acquisition and registration in the example application of partial nephrectomies. Furthermore, the benefits of elastography vs. conventional B-Mode ultrasound imaging are investigated.

Chen, Min (Ed.) et al.: WSCG 2009. Communication Papers Proceedings. Plzen: University of West Bohemia, 2009, pp. 1-8

In this paper we present a hybrid technique for illuminating a dynamic scene with self shadowing. Our goal is to perform the necessary calculations with real-time or interactive frame rates. The main idea is to split up the self shadowing process into a global and a local part. This separation allows us to choose combinations of completely independent algorithmic approaches. The global part calculates the self shadowing information of the entire scene. Since it has to process the whole scene, it has a high computational cost; however, a coarse approximation can be created in a short time. In contrast the process for the local part deals with fine details, which have local impact on the scene. It only processes a relevant subset of the scene. Finally we present results based on an implementation using a GPU based self shadowing approximation combined with screen space ambient occlusion for solving the local part.

Tai, Xue-Cheng (Ed.) et al.: Scale Space and Variational Methods in Computer Vision. Proceedings. Berlin, Heidelberg, New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS) 5567), pp. 844-855

In this work we describe the possible transitions for the hierarchical structure that describes an image in Gaussian scale space. Until now, this tree structure has only been used for topological segmentation. In order to perform image matching and retrieval tasks based on this structure, one needs to know which transitions are allowed when the structure is changed under influence of one control parameter. We present a list of such transitions, enabling tree edit distance operations.

Stasko, John (Ed.) et al.: IEEE Symposium on Visual Analytics Science and Technology 2009. Proceedings : VAST 2009. New York: IEEE Press, 2009, pp. 155-162

In this paper, we present a system for the interactive visualization and exploration of graphs with many weakly connected components. The visualization of large graphs has recently received much research attention. However, specific systems for visual analysis of graph data sets consisting of many such components are rare. In our approach, we rely on graph clustering using an extensive set of topology descriptors. Specifically, we use the Self-Organizing- Map algorithm in conjunction with a user-adaptable combination of graph features for clustering of graphs. It offers insight into the overall structure of the data set. The clustering output is presented in a grid containing clusters of the connected components of the input graph. Interactive feature selection and task-tailored data views allow the exploration of the whole graph space. The system provides also tools for assessment and display of cluster quality. We demonstrate the usefulness of our system by application to a shareholder structure analysis problem based on a large real-world data set. While so far our approach is applied to weighted directed graphs only, it can be used for various graph types.

HCI International 2009. Proceedings and Posters [DVD-ROM] : With 10 further Associated Conferences. Berlin, Heidelberg, New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS)), LNCS 5615, pp. 228-237

This paper describes a modeling framework that facilitates and streamlines the process of creation, design, construction and deployment of technological solutions in the context of AAL assuring that they are accessible and usable for senior citizens. The framework supports the design of the Human Interaction aspects of an AAL solution in all the stages of a user centered design methodology, putting in practice the guidelines for the verification and validation of the accessibility and usability facets. Two environments are defined: The authoring environment allow the definition of the user, environment and service models. The simulation environment is composed by software and hardware components that constitute a physical ensemble that in conjunction allow the ICT designer to implement actual Virtual Reality scenarios of AAL. It will be used to verify interaction designs and validate the accessibility of the AAL products by means of immersing the users in 3D virtual spaces.

HCI International 2009. Proceedings and Posters [DVD-ROM] : With 10 further Associated Conferences. Berlin, Heidelberg, New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS)), LNCS 5616, pp. 83-91

The enhancement of the individual knowledge is a basic need that came up with changes in our society, whereas the process of learning disappears more and more. In the recent past the disappearance of a predefined learning process was named ambient learning, which came up to cope the changing need of every time and everywhere learning. Learning contents get more structure by new technologies like semantics, which specifies and defines more the semantic structure and with it the meaning of information. Users working with information system are confronted with different processes for getting the required information. The following paper introduces a new visualization technique, which uses the everyday processes of information search for imparting knowledge. The visualization technique utilizes the surplus of semantics to encourage the process of ambient learning.

Tao, Jianhua (Ed.) et al.: Affective Information Processing. London: Springer, 2009, pp. 303-322

Sensing affective states is a challenging undertaking and a variety of approaches exist. One of the oldest but yet often neglected way is to observe physiological processes related to sympathetic activity of the autonomic nervous system. A reason for physiological measurements not being used in emotionrelated HCI research or affective applications is the lack of appropriate sensing devices. Existing systems often don't live up to the high requirements of the real life such applications are to be used in. This paper starts with a short overview of physiological processes affective applications rely on today, and commonly used techniques to access them. After this, requirements of affective applications for physiological sensors are worked out. A design concept meeting the requirements is drawn and exemplary implementations including evaluation results are described.

Prautzsch, Hartmut (Ed.) et al.: VRIPHYS 09: 6th Workshop in Virtual Reality Interactions and Physical Simulations. Proceedings. Goslar: Eurographics Association, 2009, pp. 95-103

A linear system is a fundamental building block for several mesh-based computer graphics applications such as simulation, shape deformation, virtual surgery, and fluid/smoke animation, among others. Nevertheless, such a system is most of the times seen as a black box and algorithms do not deal with its optimization. Depending on the number of unknowns, the linear system is often considered as an obstacle for real time application and as a building block for offline computations. We present in this paper, a neighboring-based methodology for representing a linear system. This new representation enables a compact storage of the set of equation, flexibility for ordering the unknowns and a rapid iterative solution, by means of an optimized matrix-vector multiplication. In addition, this representation facilitates the modification of part of the linear system without affecting its unchanged part and avoiding the complete rebuild of the system. This specially benefits applications dealing with dynamic meshes, where the geometry, the topology or both are constantly changed. We present the capabilities of our methodology in models with different sizes and for different operations, highlighting the dynamic characteristic of the mesh. We believe that several applications in computer graphics could benefit from our methodology, in order to improve their convergence and their performance, reducing the number of iterations and the computation time.

Antoniou, G. E. (Ed.) et al.: Proceedings of the International Conference on Computing, Engineering and Information : ICC 2009. Los Alamitos, Calif.: IEEE Computer Society, 2009, pp. 329-332

The computational mechanics suffers a lack of modifiability and interactivity, which leads to neglecting its potential to help engineers in solving problems faster and cheaper. The fully integration of computer design in computational mechanics will tackle this problems, by means of providing the capability to explore design variations within an analysis environment and with a direct feedback from the mechanical simulation. Our paper states the advantages of such a solution and presents a theoretical concept, which can enrich computational mechanics with modeling functionalities from computer design, enabling a design-analysis iteration loop.

Computer Aided Geometric Design, Vol.26 (2009), 8, pp. 825-841

We describe an approximating scheme for the smooth reconstruction of discrete data on volumetric grids. A local quasi-interpolation method for quadratic C1-splines on uniform tetrahedral partitions is used to achieve a globally smooth function. The Bernstein-Bézier coefficients of the piecewise polynomials are thereby directly determined by appropriate combinations of the data values. We explicitly give a construction scheme for a family of quasi-interpolation operators and prove that the splines and their derivatives can provide an approximation order two for smooth functions. The optimal approximation of the derivatives and the simple averaging rules for the coefficients recommend this method for high quality visualization of volume data. Numerical tests confirm the approximation properties and show the efficient computation of the splines.

International Journal of Computer Vision, Vol.82 (2009), 2, pp. 205-229

We develop a framework for learning generic, expressive image priors that capture the statistics of natural scenes and can be used for a variety of machine vision tasks. The approach provides a practical method for learning high-order Markov random field (MRF) models with potential functions that extend over large pixel neighborhoods. These clique potentials are modeled using the Product-of-Experts framework that uses non-linear functions of many linear filter responses. In contrast to previous MRF approaches all parameters, including the linear filters themselves, are learned from training data. We demonstrate the capabilities of this Field-of-Experts model with two example applications, image denoising and image inpainting, which are implemented using a simple, approximate inference scheme. While the model is trained on a generic image database and is not tuned toward a specific application, we obtain results that compete with specialized techniques.

IEEE Computer Society: IEEE Conference on Computer Vision and Pattern Recognition. Conference DVD-ROM : CVPR 2009. New York: IEEE, 2009, pp. 2238-2245

A variety of flexible models have been proposed to detect objects in challenging real world scenes. Motivated by some of the most successful techniques, we propose a hierarchical multi-feature representation and automatically learn flexible hierarchical object models for a wide variety of object classes. To that end we not only rely on automatic selection of relevant individual features, but go beyond previous work by automatically selecting and modeling complex, long-range feature couplings within this model. To achieve this generality and flexibility our work combines structure learning in conditional random fields and discriminative parameter learning of classifiers using hierarchical features. We adopt an efficient gradient based heuristic for model selection and carry it forward to discriminative, multidimensional selection of features and their couplings for improved detection performance. Experimentally we consistently outperform the currently leading method on all 20 classes of the PASCAL VOC 2007 challenge and achieve the best published results on 16 of 20 classes.

Information Visualization, Vol.8 (2009), 1, pp. 14-29

Visual-interactive cluster analysis provides valuable tools for effectively analyzing large and complex data sets. Due to desirable properties and an inherent predisposition for visualization, the Kohonen Feature Map (or Self-Organizing Map, or SOM) algorithm is among the most popular and widely used visual clustering techniques. However, the unsupervised nature of the algorithm may be disadvantageous in certain applications. Depending on initialization and data characteristics, cluster maps (cluster layouts) may emerge that do not comply with user preferences, expectations, or the application context. Considering SOM-based analysis of trajectory data, we propose a comprehensive visual-interactive monitoring and control framework extending the basic SOM algorithm. The framework implements the general Visual Analytics idea to effectively combine automatic data analysis with human expert supervision. It provides simple, yet effective facilities for visually monitoring and interactively controlling the trajectory clustering process at arbitrary levels of detail. The approach allows the user to leverage existing domain knowledge and user preferences, arriving at improved cluster maps. We apply the framework on a trajectory clustering problem, demonstrating its potential in combining both unsupervised (machine) and supervised (human expert) processing, in producing appropriate cluster results.

IEEE Computer Society: Proceedings of the 23th International Parallel and Distributed Processing Symposium : IPDPS 2009. Los Alamitos, Calif.: IEEE Computer Society, 2009, 8 p.

Emerging DNA sequencing technologies open up exciting new opportunities for genome sequencing by generating read data with a massive throughput. However, produced reads are significantly shorter and more error-prone compared to the traditional Sanger shotgun sequencing method. This poses challenges for de-novo DNA fragment assembly algorithms in terms of both accuracy (to deal with short, error-prone reads) and scalability (to deal with very large input data sets). In this paper we present a scalable parallel algorithm for correcting sequencing errors in high-throughput short-read data. It is based on spectral alignment and uses the CUDA programming model. Our computational experiments on a GTX 280 GPU show runtime savings between 10 and 19 times (for different error-rates using simulated datasets as well as real Solexa/Illumina datasets).

IEEE 12th International Conference on Computer Vision Workshops : ICCV Workshops [DVD-ROM]. Los Alamitos, Calif.: IEEE Computer Society, 2009, pp.649-656

Recognition of object classes in natural images has made tremendous progress in recent years. Today's approaches often rely on powerful learning approaches as well as robust local 2D shape or appearance features. Exploiting 3D shape cues however has become unfashionable in recent literature. While shading cues play a major role in human perception of object shape, shape-from-shading techniques are seldom used today for object class detection. Drawing on ideas from the early days in object recognition this paper aims to revisit the concept of using shading primitives to support object class detection. We demonstrate and discuss the applicability of this approach to real world images of a standard benchmark data set. Experimental results suggest that our shading cues can be useful for object class detection.

IEEE 12th International Conference on Computer Vision : ICCV 2009 [DVD-ROM]. Los Alamitos, Calif.: IEEE Computer Society, 2009, pp. 373-380

Object class models trained on hundreds or thousands of images have shown to enable robust detection. Transferring knowledge from such models to new object classes trained from a few or even as little as one training instance however is still in its infancy. This paper designs a shape-based model that allows to easily and explicitly transfer knowledge on three different levels: transfer of individual parts' shape and appearance information, transfer of local symmetry between parts, and transfer of part topology. Due to the factorized form of the model, knowledge can either be transferred for the complete model or just partial knowledge corresponding to certain aspects of the model. The experiments clearly demonstrate that the proposed model is competitive with the state-of-the-art and enables both full and partial knowledge transfer.

Debattista, Kurt (Ed.) et al.: VAST 2009. Proceedings. Aire-la-Ville: Eurographics Association, 2009, pp. 117-124

Sharing 3D models with embedded annotations and additional information in a general accessible way still is a major challange. Using 3D technologies must become much easier, in particular in areas such as Cultural Heritage, where archeologists, art historians, and museum curators rely on robust, easy to use solutions. Sustainable exchange standards are vital since unlike in industry, no sophisticated PLM or PDM solutions are common in CH. To solve this problem we have examined the PDF file format and developed concepts and software for the exchange of annotated 3D models in a way that is not just comfortable but also sustainable. We show typical use cases for authoring and using PDF documents containing annotated 3D geometry. The resulting workflow is eficient and suitable for experienced users as well as for users working only with standard word processing tools and e-mail clients (plus, currently, Acrobat Pro Extended).

Léger, Alain (Ed.) et al.: Proceedings of the 3rd International Workshop on Service Matchmaking and Resource Retrieval in the Semantic Web : SMR2 2009. [cited 29 March 2010] Available from: http://ftp.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-525/ 2009. (CEUR Workshop Proceedings 525), 15 p.

A vision of the Semantic Web is to facilitate global software interoperability. Many approaches and specifications are available that work towards realization of this vision: Service-oriented architectures (SOA) provide a good level of abstraction for interoperability; Web Services provide programmatic interfaces for application to application communication in SOA; there are ontologies that can be used for machine-readable description of service semantics. What is still missing is a standard for constructing semantically formulated service requests that solely rely on shared domain ontologies without depending on programmatic or even semantically described interfaces. Such a standard would facilitate the realization of Semantic RPC as the whole process from issuing such a request, matchmaking with semantic profiles of available and accessible services, deriving input parameters for the matched service(s), calling the service(s), getting the results, and mapping back the results onto an appropriate response to the original request. The standard must avoid realization-specific assumptions so that frameworks supporting semantic RPC can be built for bridging the gap between the semantically formulated service requests and matched programmatic interfaces. This paper introduces a candidate solution to this problem by outlining a query language for semantic service utilization based on an extension of the OWL-S ontology for service description.

IEEE Systems, Man and Cybernetics Society: IEEE International Conference on Systems, Man and Cybernetics : SMC 2009. New York: IEEE Press, 2009, pp. 857-862

In recent years, the demand for efficient systems which can capture and learn human skills has become increasingly important. In this paper an approach for acquiring and recognizing human assembly skills is presented. The underlying workflows of assembly skills are captured by using a simple multisensor data glove and camera tracking. To avoid the processing of redundant information, at first the relevant tasks of a workflow are identified by analyzing measuring information of the multisensor capturing system. Thus, only relevant data is comprised in the representation of a workflow. Unlike common approaches a workflow is modeled as entire unit using a continuous Hidden Markov Model (HMM). The recognition process of input patterns is based on an adaptive threshold model that can identify known workflow patterns and non-meaningful input patterns as well.

Banissi, Ebad (Ed.) et al.: Proceedings Second International Conference in Visualisation. VIZ 2009 : Visualisation in Built and Rural Environments - BioMedical Visualisation - Geometric Modelling and Imaging. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2009, 6 p.

Transfer functions (TF) are a means for improving the visualization of 3D medical image data. If in addition to intensity another property is employed, two-dimensional TFs can be specified. For this, 2D histograms are helpful. In this work we investigate how the property feature size can be used for the definition of 2D TFs and the visualization of medical image data. Furthermore, we compare this method to approaches that employ gradient magnitude as second property. From our experiments with several medical image data we conclude, that structure size enhanced 2D histograms are more intuitive. This is especially true in the clinical area, where physicians are much more familiar with the meaning of the size of anatomical structures than with the concept of gradient magnitude.

IEEE Systems, Man and Cybernetics Society: IEEE International Conference on Systems, Man and Cybernetics : SMC 2009. New York: IEEE Press, 2009, pp. 565-570

This paper presents a simple yet effective approach for classification of human postures by using a time-of-flight camera. We investigate and adopt linear projection techniques such as Locality Preserving Projections (LPP), Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA), which are more widespread in face recognition and other pattern recognition tasks.We analyze the relations between LPP and LDA and show experimentally that using LPP in a supervised manner effectively yields very similar results as LDA, implying that LPP may be regarded as a generalization of LDA. Features for offline training and online classification are created by adopting common image processing techniques such as background-subtraction and blob detection to the time-of-flight data.

Mohamed, Kamel (Ed.) et al.: Image Analysis and Recognition : 6th International Conference, ICIAR 2009. Berlin; Heidelberg; New York: Springer, 2009. (Lecture Notes in Computer Science (LNCS) 5627)

Biometric features provide considerable usability benefits. At the same time, the inability to revoke templates and likelihood of adversaries being able to capture features raise security concerns. Recently, several template protection mechanisms have been proposed, which provide a one-way mapping of templates onto multiple pseudo-identities. While these proposed schemes make assumptions common for cryptographic algorithms, the entropy of the template data to be protected is considerably lower per bit of key material used than assumed owing to correlations arising from the biometric features. We review several template protection schemes and existing attacks followed by a correlation analysis for a selected biometric feature set and demonstrate that these correlations leave the stream cipher mechanism employed vulnerable to, among others, known plaintext-type attacks.

Debattista, Kurt (Ed.) et al.: VAST 2009. VAST-STAR, Short and Project Papers Proceedings. Msida: University of Malta, 2009, pp. 112-116

Museums often lack the possibilitiy to present archaeological or cultural heritage sites in a realistic and interesting way. Thus are proposing a new way to show augmented reality applications of cultural heritage sites at remote places like museums. In the exhibition space large wall-filling photographs of the real site are superimposed with interactive contextual annotations like 3D reconstructions, images and movies. Therefore we are using two different hardware setups for visualization: Standard UMPCs and a custom made revolving display. The setup has been installed and tested at SIGGRAPH 2008, Allard Pierson Museum in Amsterdam and CeBIT 2009. Museum visitors could experience Forum Romanum and Saticum in an informative and intuitive way by pointing the video see through devices on different areas of the photographs. The result is a more realistic and entertaining way for presenting cultural heritage sites in museums. Furthermore our solution is less expensive than comparable installations regarding content and hardware.