Liste der Fachpublikationen

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3D Mass Digitization: A Milestone for Archeological Documentation

2017

VAR. Virtual Archaeology Review [online], Vol.8 (2017), 16, pp. 1-11

In the heritage field the demand for fast and efficient 3D digitization technologies for historic remains is increasing. Besides, 3D digitization has proved to be a promising approach to enable precise reconstructions of objects. Yet, unlike the digital acquisition of cultural goods in 2D widely used today, 3D digitization often still requires a significant investment of time and money. To make it more widely available to heritage institutions, the Competence Center for Cultural Heritage Digitization at the Fraunhofer Institute for Computer Graphics Research IGD has developed CultLab3D, the world's first fully automatic 3D mass digitization facility for collections of three-dimensional objects. CultLab3D is specifically designed to automate the entire 3D digitization process thus allowing users to scan and archive objects on a large-scale. Moreover, scanning and lighting technologies are combined to capture the exact geometry, texture, and optical material properties of artefacts to produce highly accurate photo-realistic representations. The unique setup allows shortening the time needed for digitization to several minutes per artefact instead of hours, as required by conventional 3D scanning methods.

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Getto, Roman; Merz, Johannes; Kuijper, Arjan; Fellner, Dieter W.

3D Meta Model Generation with Application in 3D Object Retrieval

2017

Mao, Xiaoyang (Ed.) et al.: CGI 2017. Proceedings of the Computer Graphics International Conference. New York: ACM, 2017. (ACM International Conference Proceedings Series (ICPS) 1368), 6 p.

Computer Graphics International (CGI) <34, 2017, Yokohama, Japan>

In the application of 3D object retrieval we search for 3D objects similar to a given query object. When a user searches for a certain class of objects like 'planes' the results can be unsatisfying: Many object variations are possible for a single class and not all of them are covered with one or a few example objects. We propose a meta model representation which corresponds to a procedural model with meta-parameters. Changing the meta-parameters leads to different variations of a 3D object. For the meta model generation a single object is constructed with a modeling tool. We automatically extract a procedural representation of the object. By inserting metaparameters we generate our meta model. The meta model defines a whole object class. The user can choose a meta model and search for all objects similar to any instance of the meta model to retrieve all objects of a certain class from a 3D object database. We show that the retrieval precision is signifcantly improved using the meta model as retrieval query.

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3D-printed Electrodes for Electric Field Sensing Technologies

2017

Darmstadt, TU, Master Thesis, 2017

Electrical field sensing and capacitive sensing have been an intensively explored research topic for over a century. Combined with the rising popularity of rapid prototyping technologies, like affordable all- in-one micro-controller boards and especially fused filament fabrication 3D-printing, new possibilities occur. 3D-printing drives the ambitions of custom designed objects with fully integrated and unobtrusive electronics. Conductive 3D-printing materials (filaments) can be used to create electrodes for electrical field sensing. These electrodes can be 3D-printed as an integral part into the overall object. However, none of the previous work examines the properties of these conductive materials, the chosen 3D-printing configurations, and patters regarding their sensing performance and costs. This thesis provides a first insight into the interdependency between the chosen 3D- printing parameters and the overall sensing performance. For this, 30 3D-printed electrodes were created from graphene filament and evaluated against one copper electrode, and a placebo electrode. The evaluation was performed by a custom made measuring toolkit, the CapLiper, which was also evaluated for proper sensing behavior. The results show, that 3D-printed electrodes can compete with the sensing performance of copper electrodes, with some exceeding its performance. Using these results, as well as lessons learned in creating two different prototypes, the thesis establishes best practice and gives an outlook on potential future work in this domain.

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Acceleration of 3D Mass Digitization Processes: Recent Advances and Challenges

2017

Ioannides, Marinos (Ed.) et al.: Mixed Reality and Gamification for Cultural Heritage. Springer International Publishing, 2017, pp. 99-128

In the heritage field, the demand for fast and efficient 3D digitization technologies for historic remains is increasing. Besides, 3D has proven to be a promising approach to enable precise reconstructions of cultural heritage objects. Even though 3D technologies and postprocessing tools are widespread and approaches to semantic enrichment and Storage of 3D models are just emerging, only few approaches enable mass capture and computation of 3D virtual models from zoological and archeological findings. To illustrate how future 3D mass digitization systems may look like, we introduce CultLab3D, a recent approach to 3D mass digitization, annotation, and archival storage by the Competence Center for Cultural Heritage Digitization at the Fraunhofer Institute for Computer Graphics Research IGD. CultLab3D can be regarded as one of the first feasible approaches worldwide to enable fast, efficient, and cost-effective 3D digitization. lt specifically designed to automate the entire process and thus allows to scan and archive large amounts of heritage objects for documentation and preservation in the best possible quality, taking advantage of integrated 30 visualization and annotation within regular Web browsers using technologies such as WebGI and X3D.

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Accurate Physics-Based Registration for the Outcome Validation of Minimal Invasive Interventions and Open Liver Surgeries

2017

IEEE Transactions on Biomedical Engineering, Vol.64 (2017), 2, pp. 362-371

The purpose of this paper is to present an outcome validation tool for tumor radiofrequency (RF) ablation and resection. Methods: Intervention assessment tools require an accurate registration of both pre- and postoperative computed tomographies able to handle big deformations. Therefore, a physics-based method is proposed with that purpose. To increase the accuracy both automatically detected internal and surface physical landmarks are incorporated in the registration process. Results: The algorithm has been evaluated in 25 clinical datasets containing RF ablations, resections, and patients with recurrent tumors. The achieved accuracy is 1.2 mm measured as mean internal distance between vessel landmarks and a positive predictive value of 0.95. The quantitative and qualitative results of the outcome validation tool show that in 50% of the cases tumors were only partially covered by the treatment. Conclusion: The use of internal and surface landmarks combined with a physics-based registration method increases the accuracy of the results compared to the accuracy of state of the art methods. An accurate outcome validation tool is important in order to certify that the tumor and its safety margin were fully covered by the treatment. Significance: An accurate outcome validation tool can result in a decrease of the tumor recurrence rate.

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Gangatharan, Dinesh Vaithyalingam; Kupnik, Mario (Betreuer); Fu, Biying (Betreuer)

Activity Recognition On Unmodified Consumer Smartphones Via Active Ultrasonic Sensing

2017

Darmstadt, TU, Master Thesis, 2017

Sensor miniaturisation and streaming classification techniques can be used to recognize human behaviours and contexts. This is extremely valuable to realize smart environments, e.g. to support healthy and independent living. The most important parameters to sense include indoor location, gestures, or emergencies like falls. Up to now, activity recognition systems face a number of sensitive drawbacks. For example, camera-based systems induce privacy issues and are costly to deploy. Body-worn systems are inconvenient to wear over long periods of time. Highly visible systems may introduce social stigma and modify the well-known living environment. In this project, we explore the possibility for the use of a new, unobtrusive, physical principle to sense and recognize human activities using off-the-shelf smart-phone. A person's smart-phone is a cornucopia of information. The huge variety of sensors in today's mobile phones makes these devices a prime target for human activity recognition. Our novel approach is to develop a novel activity recognizing system using an unmodified smart-phone. We profit from integrated microphones and loudspeakers without additional hardware components needed. The advantage of this system is therefore that it can be easily installed on a smart-phone and put into action. An android application has already been developed which is able to send a high frequency sound in the near ultrasound range, e.g. 20 kHz. Using the received echo from the microphone, the information caused by movement in midair around the device will be extracted. In this thesis we intend to improve the performance of the existing system with respect to noise cancellation and other classification schemes. In this thesis, we present an android application called Trainer for complex activity recognition. It is built on ultrasense [8], a mobile application that capitalizes the characters of ultrasound to inspect the surrounding environment. The application is able to send a high frequency signal in the near ultrasound range, e.g. 20 kHz. Using the received echo from the microphone, the information caused by movement in midair around the device will be extracted. Complex activities tagged under home exercises are evaluated using micro-Doppler signatures [mD-signatures]. We propose an algorithm to classify a set of exercises carried out by the user and show that using the Support vector machine classifier we are able to obtain an accuracy of 85% using Principal component analysis and a signature feature introduced in this thesis as a feature.

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Braun, Andreas; Wichert, Reiner

Ambient Intelligence: 13th European Conference, AmI 2017

2017

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Lecture Notes in Computer Science (LNCS) 10217

The AmI 2017 conference solicited contributions with the themes of: - Enabling Technologies, Methods and Platforms - Objectives and Approaches of Ambient Intelligence and Internet of Things - From Information Design to Interaction and Experience Design - Application Areas of AmI and IoT

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Applying the PROSA Reference Architecture to Enable the Interaction between the Worker and the Industrial Robot: Case Study: One Worker Interaction with a Dual-Arm Industrial Robot

2017

Herik, Jaap van den (Ed.) et al.: ICAART 2017 Vol. 1 : Proceedings of the 9th International Conference on Agents and Artificial Intelligence. SciTePress, 2017, pp. 190-199

International Conference on Agents and Artificial Intelligence (ICAART) <9, 2017, Porto, Portugal>

Involving an industrial robot in a close physical interaction with the worker became quite possible, as a result of the availability of different collaborative industrial robots in the market. The physical cooperation between the industrial robot and the worker usually done under the umbrella of the flexible manufacturing paradigm, where both the industrial robot and the worker need to change their tasks fast and efficiently, to cope with the changes in the manufacturing process. This means that a reliable manufacturing control system must stand behind this physical interaction to achieve the proper communication interaction. A holonic control architecture is an ideal solution for this problem. Therefore, during this research we study the most commonly applied model of the holonic control architecture, then we apply this architecture on our case study, where one worker cooperates with a dual-arm industrial robot to build and produce any new product. Also the research uses the worker's hand gesture recognition as a method to interact with the industrial robot during the execution of a cooperative production scenario.

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Approaches and Challenges in the Visual-interactive Comparison of Human Motion Data

2017

Linsen, Lars (Ed.) et al.: IVAPP 2017. Proceedings : 8th International Conference on Information Visualization Theory and Applications (VISIGRAPP 2017 Volume 3). SciTePress, 2017, pp. 217-224

International Conference on Information Visualization Theory and Applications (IVAPP) <8, 2017, Porto, Portugal>

Many analysis goals involving human motion capture (MoCap) data require the comparison of motion patterns. Pioneer works in visual analytics recently recognized visual comparison as substantial for visual-interactive analysis. This work reflects the design space for visual-interactive systems facilitating the visual comparison of human MoCap data, and presents a taxonomy comprising three primary factors, following the general visual analytics process: algorithmic models, visualizations for motion comparison, and back propagation of user feedback. Based on a literature review, relevant visual comparison approaches are discussed. We outline remaining challenges and inspiring works on MoCap data, information visualization, and visual analytics.

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Behr, Johannes; Blach, Roland; Bockholt, Ulrich; Harth, Andreas; Hoffmann, Hilko; Huber, Manuel; Käfer, Tobias; Keppmann, Felix Leif; Pankratz, Frieder; Rubinstein, Dmitri; Schubotz, René; Vogelgesang, Christian; Voss, Gerrit

ARVIDA-Referenzarchitektur: Ressourcen-orientierte Architekturen für die Anwendungsentwicklung Virtueller Techniken

2017

Schreiber, Werner (Ed.) et al.: Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie. Berlin: Springer Vieweg, 2017, pp. 117-191

Die ARVIDA-Referenzarchitektur ist ein zentrales Element und Ergebnis des ARVIDA- Projektes. Sie ermöglicht es, mit etablierten Technologien und Konzepten aus dem Web-Umfeld heterogene VT-Systemlandschaften in integrierten, sehr weitgehend plattformunabhängigen VT-Anwendungen effizient zu nutzen. Die Referenzarchitektur nutzt und adaptiert das Prinzip der RESTful-Web-Services sowie die darauf aufbauenden Linked-Data Konzepte, um interoperable, leicht erweiterbare und modulare VTAnwendungen zu bauen. Die nachfolgenden Abschnitte beschreiben die Grundprinzipien und spezifischen Erweiterungen im Detail.

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Alvarado, Pablo; Bockholt, Ulrich; Canzler, Ulrich; Herbort, Steffen; Heuser, Nicolas; Keitler, Peter; Krzikalla, Roland; Olbrich, Manuel; Prager, André; Schröder, Frank; Schwerdt, Jörg; Willneff, Jochen; Zürl, Konrad

ARVIDA-Technologien

2017

Schreiber, Werner (Ed.) et al.: Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie. Berlin: Springer Vieweg, 2017, pp. 193-217

Dieses Kapitel beschreibt Technologien im Kontext von ARVIDA, die über die allgemeine Beschreibung von Technologien aus Kap. 2 hinausgehen. Eine der Hürden für den produktiven Einsatz von VT ist der Mangel an robusten, markerlosen Trackingsystemen. Hier wurden im Rahmen des Projektes essentielle Fortschritte gemacht. Auch bei der Gestenerkennung konnten im Rahmen der Interaktion in einer Sitzkiste wesentliche Verbesserungen erzielt werden. Die Vermessung von Geodaten ist eine Grundvoraussetzung für Anwendungen im Digitalen Fahrzeugerlebnis. Hier wurden ebenfalls deutliche Fortschritte erzielt. Schließlich ist zu erwähnen, dass die vorgestellten Technologien als Dienste der Referenzarchitektur bereitgestellt werden, um den Austausch von Technologien einfach zu gestalten.

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Rus, Silvia; Caliz, Doris; Braun, Andreas; Engler, Anne; Schulze, Eva

Assistive Apps for Activities of Daily Living Supporting Persons with Down's Syndrome

2017

Journal of Ambient Intelligence and Smart Environments, Vol.9 (2017), 5, pp. 611-623

Supporting persons with Down's Syndrome in their daily activities using ICT is a key element in further advancing their independence and integration into society. The POSEIDON project embraces this goals and develops technology which creates adjustable and personalizable assistive systems. We present a system for Money-Handling Training and assistance for shopping. In this paper we present results of evaluating the Money-Handling Training App in different pilot studies and work-shops, with a larger group of persons with Down's Syndrome, comparing different interaction devices like tablet, personal computer and interactive table. Furthermore, we present evaluation results for the Shopping App.

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Frank, Sebastian; Kuijper, Arjan

AuthentiCap - A Touchless Vehicle Authentication and Personalization System

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 46-63

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Current authentication systems in vehicles use portable keys or biometric and/or touch based inputs. They can be outwitted by stealing the keys or by copying the biometric information and analyzing the touch marks. This has to be inhibited, since vehicles are not only an expensive property, that would be lost in non-authenticated hands, but wrong permitted access also can unleash heavy machine power to inexperienced drivers or even people without a driver's license. We present a system that authenticates drivers and unlocks personalization features without any portable keys or touching. Moreover, it is invisibly integrated into a vehicle structure, the steering wheel. In contrast to biometric authentication, the password pattern is adjustable and changeable. With the presented system, vehicle manufactures are able to install driver authentication systems without any visible design changes. The manufacturer thus provides more freedom and responsibility to the driver by giving him the option to choose his own unlock pattern. Still, the security is increased by avoiding common vulnerabilities like smudge attacks, the stealing of keys, or copying of biometric data. Our experiments show excellent recognition rates for multiple string patterns. A small user study shows that our system achieves 86% accuracy for inexperienced users, up to 96% for experienced ones. The users appreciated the easy of use.

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Fina, Kenten; Kuijper, Arjan (Betreuer); Getto, Roman (Betreuer)

Automated Detection of Significant Parameters in Procedural 3D Models

2017

Darmstadt, TU, Bachelor Thesis, 2017

This bachelor thesis present an approach to automatically detect significant parameters in a procedural model. For the distinction of significant and insignificant parameters we present both a static version and a method using machine learning. In the process parameters are grouped, which represent symmetries or other relations in the model. Additionally we allow the user to adapt the selection of significant parameters to his needs. For this purpose we support the user by visualizing the changes of a parameter. Furthermore a hierarchical arrangement of the parameters is done to give the user an overview of all design possibilities. Subsequently, we show how ranges for the selected parameters can be calculated, which retain the object.

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Jung, Florian; Biebl-Rydlo, Medea; Daisne, Jean-François; Wesarg, Stefan

Automatic Sentinel Lymph Node Localization in Head and Neck Cancer Using a Coupled Shape Model Algorithm

2017

Cardoso, Jorge M. (Ed.) et al.: Computer Assisted and Robotic Endoscopy and Clinical Image-Based Procedures : 4th International Workshop, CARE 2017 and 6th International Workshop, CLIP 2017. Held in Conjunction with MICCAI 2017.. Berlin, Heidelberg, New York: Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10550), pp. 133-140

The localization and analysis of the sentinel lymph node for patients diagnosed with cancer, has significant influence on the prognosis, outcome and treatment of the disease. We present a fully automatic approach to localize the sentinel lymph node and additional active nodes and determine their lymph node level on SPECT-CT data. This is a crucial prerequisite for the planning of radiation therapy or a surgical neck dissection. Our approach was evaluated on 17 lymph nodes. The detection rate of the lymph nodes was 94%; and 88% of the lymph nodes were correctly assigned to their corresponding lymph node level. The proposed algorithm targets a very important topic in clinical practice. The first results are already very promising. The next step has to be the evaluation on a larger data set.

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Hartwig, Katrin; Sakas, Georgios (Betreuer); Oyarzun Laura, Cristina (Betreuer)

Automatische Segmentierung der Nasenscheidewand auf Basis von computertomographischen Bilddaten

2017

Darmstadt, TU, Bachelor Thesis, 2017

Im Kontext der Nasenheilkunde spielt die Segmentierung der Nasenscheidewand anhand von computertomographischen Bildern eine wichtige Rolle für Diagnose, präoperative Planung und Behandlung. Aktuelle Verfahren stützen sich zumeist auf manuelle Segmentierung, welche für den medizinischen Alltag zu zeitintensiv ist. In der vorliegenden Bachelorarbeit wurde daher ein vollautomatisches Verfahren entwickelt, welches an die anatomischen Besonderheiten und computationellen Herausforderungen der Nasenscheidewand adaptiert ist. Dabei wurde eine Kombination aus Musterdetektion und Slice-based Propagation angewandt. Die Evaluation anhand von 19 Datensätzen zeigt mit durchschnittlich 0,78 Sekunden pro CT-Bild eine deutliche Beschleunigung im Vergleich zu manuellen Verfahren und erzielt auch im Bezug auf die Genauigkeit der Segmentierung mit einem durchschnittlichen DSC-Wert von 0,8665 annehmbare Ergebnisse.

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Bauer, Johann; Urban, Bodo (Betreuer); Aehnelt, Mario (Betreuer)

Automatisches Generieren von Instruktionen im Plant@Hand Montageassistenzsystem

2017

Rostock, Univ., Bachelor Thesis, 2017

Das Plant@Hand-Montageassistenzsystem unterstützt Montagearbeiter bei der variantenreichen Fertigung von Kleinstserien. Das Ziel der vorliegenden Bachelorarbeit war die Entwicklung eines Konzepts, das die Methoden des Cognitive-Apprenticeship Modells zur automatisierten Anpassung dieser Assistenz an den Montagearbeiter nutzt. Ein Teil des entwickelten Konzepts wurde prototypisch im Plant@Hand-Montageassistenzsystem umgesetzt.

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Sagare, Anagha; Kuijper, Arjan (Betreuer); Fu, Biying (Betreuer)

Best Practices to Visualize Activity Data in Mobile Apps

2017

Darmstadt, TU, Master Thesis, 2017

Physical activity and exercise are essential factors to live a healthy life. Fitness trackers have great potential to assist individuals in making healthy changes to their lifestyle. A variety of fitness trackers are available in the market such as fitness apps based on mobile platform, wearable sensors (e.g. smartwatch, armband, wristband), balancing boards (e.g. Wii fit) etc. In this thesis, the focus is on fitness apps based on mobile platform. These apps provide different information and features to the user such as a summary of the physical activity performed, feedback of the activity (e.g. through virtual trainer), exercise plans according to the user's workout routine, user's achievements and many more. Also, fitness apps aim to present a lot of statistical data to the users regarding their current or previous physical activity which may range from days to years. To visualize this data, visual designs such as maps, graphs, images are used. However, very little is known about such visualization schemes and design strategies for fitness data w.r.t engaging users. Furthermore, it is important to know if the provided features in the app are useful. The main objective of this study is to evaluate different visualization schemes used in visualizing fitness data and to explore usability requirements, motivating factors for using mobile fitness apps. For this purpose, a profound research is done in three phases. The first phase focuses on finding expectations of a user from fitness app through a short primary survey in University Gym, the second phase includes designing an extensive user survey and fitness app mock-ups based on the survey findings in the first phase. In the third phase, the designed mock-ups are evaluated by means of the user survey designed in second phase and the survey results are analyzed using statistical test. The study reveals that users find some visualization schemes very useful whereas they do not prefer some visualization schemes at all. Same is the case observed for motivational features e.g. ranking, rewards and other functionalities of the app e.g. workout summary, nutrition information. This thesis concludes with best practices for designing visualization schemes and analysis of user requirements for mobile fitness applications such as integrated feedback, home screen design of the app and some features like data sharing, data export etc. These findings show the way to develop highly usable fitness applications with user-centric design.

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Gao, Shan; Ye, Qixiang; Xing, Junliang; Kuijper, Arjan; Han, Zhenjun; Jiao, Jianbin; Ji, Xiangyang

Beyond Group: Multiple Person Tracking via Minimal Topology-Energy-Variation

2017

IEEE Transactions on Image Processing, Vol.26 (2017), 12, pp. 5575-5589

Tracking multiple persons is a challenging task when persons move in groups and occlude each other. Existing group-based methods have extensively investigated how to make group division more accurately in a tracking-by-detection framework; however, few of them quantify the group dynamics from the perspective of targets' spatial topology or consider the group in a dynamic view. Inspired by the sociological properties of pedestrians, we propose a novel socio-topology model with a topology-energy function to factor the group dynamics of moving persons and groups. In this model, minimizing the topologyenergy- variance in a two-level energy form is expected to produce smooth topology transitions, stable group tracking, and accurate target association. To search for the strong minimum in energy variation, we design the discrete group-tracklet jump moves embedded in the gradient descent method, which ensures that the moves reduce the energy variation of group and trajectory alternately in the varying topology dimension. Experimental results on both RGB and RGB-D data sets show the superiority of our proposed model for multiple person tracking in crowd scenes.

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CAE/VR Integration - A Path to Follow? A Validation Based on Industrial Use

2017

Zoltay Paprika, Zita (Ed.) et al.: ECMS 2017 : 31st European Conference on Modelling and Simulation, pp. 436-445

European Conference on Modelling and Simulation (ECMS) <31, 2017, Budapest, Hungary>

Numerical simulations have become crucial during the product development process (PDP) for predicting and validating different properties of new products as well as the simulation of various kinds of natural phenomena. Especially the engineering domain (CAE - Computer Aided Engineering), is seeking for new ICT solutions to cover broad ranges of physical simulations. Virtual Reality (VR) has matured in the past allowing a rapid consolidation of information and decision-making through visualization and experience. These new man machine interfaces offer advanced interaction possibilities with the digital domain and allow engineers to variate over several hypothesis. This enlightened ideas to deploy VR for "what-if-scenarios" also in the CAE domain. However, while CAD/VR integration has been sufficiently researched, the integration of CAE into VR is still facing a long road ahead. Despite recent criticism that the application of VR technology has been considered unnecessary in CAE, this paper aims to refute this by presenting methodologies for linear static FEM analysis allowing "what-if-scenarios" within interactive environments. It validates the elaborated methodologies and advantages of VR front ends by an evaluation performed within industrial engineering departments.

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CapSoles: Who Is Walking on What Kind of Floor?

2017

Association for Computing Machinery (ACM): MobileHCI 2017 : Proceedings of the 19th International Conference on Human-Computer Interaction with Mobile Devices and Services. New York: ACM, 2017, 14 p.

International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI) <19, 2017, Vienna, Austria>

Foot interfaces, such as pressure-sensitive insoles, still yield unused potential such as for implicit interaction. In this paper, we introduce CapSoles, enabling smart insoles to implicitly identify who is walking on what kind of floor. Our insole prototype relies on capacitive sensing and is able to sense plantar pressure distribution underneath the foot, plus a capacitive ground coupling effect. By using machine-learning algorithms, we evaluated the identification of 13 users, while walking, with a confidence of ~95% after a recognition delay of ~1s. Once the user's gait is known, again we can discover irregularities in gait plus a varying ground coupling. While both effects in combination are usually unique for several ground surfaces, we demonstrate to distinguish six kinds of floors, which are sand, lawn, paving stone, carpet, linoleum, and tartan with an average accuracy of ~82%. Moreover, we demonstrate the unique effects of wet and electrostatically charged surfaces.

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Change Detection in Crowded Underwater Scenes Via an Extended Gaussian Switch Model Combined with a Flux Tensor Pre-segmentation

2017

Imai, Francisco (Ed.) et al.: VISAPP 2017. Proceedings : 12th International Conference on Computer Vision Theory and Applications (VISIGRAPP 2017 Volume 4). SciTePress, 2017, pp. 405-415

International Conference on Computer Vision Theory and Applications (VISAPP) <12, 2017, Porto, Portugal>

In this paper a new approach for change detection in videos of crowded scenes is proposed with the extended Gaussian Switch Model in combination with a Flux Tensor pre-segmentation. The extended Gaussian Switch Model enhances the previous method by combining it with the idea of the Mixture of Gaussian approach and an intelligent update scheme which made it possible to create more accurate background models even for difficult scenes. Furthermore, a foreground model was integrated and could deliver valuable information in the segmentation process. To deal with very crowded areas in the scene - where the background is not visible most of the time - we use the Flux Tensor to create a first coarse segmentation of the current frame and only update areas that are almost motionless and therefore with high certainty should be classified as background. To ensure the spatial coherence of the final segmentations, the N2Cut approach is added as a spatial model after the background subtraction step. The evaluation was done on an underwater change detection datasets and showed significant improvements over previous methods, especially in the crowded scenes.

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Ceneda, Davide; Gschwandtner, Theresia; May, Thorsten; Miksch, Silvia; Schulz, Hans-Jörg; Streit, Marc; Tominski, Christian

Characterizing Guidance in Visual Analytics

2017

IEEE Transactions on Visualization and Computer Graphics, Vol.23 (2017), 1, pp. 111-120

IEEE Conference on Visual Analytics Science and Technology (VAST) <11, 2016, Baltimore, USA>

Visual analytics (VA) is typically applied in scenarios where complex data has to be analyzed. Unfortunately, there is a natural correlation between the complexity of the data and the complexity of the tools to study them. An adverse effect of complicated tools is that analytical goals are more difficult to reach. Therefore, it makes sense to consider methods that guide or assist users in the visual analysis process. Several such methods already exist in the literature, yet we are lacking a general model that facilitates in-depth reasoning about guidance. We establish such a model by extending van Wijk's model of visualization with the fundamental components of guidance. Guidance is defined as a process that gradually narrows the gap that hinders effective continuation of the data analysis. We describe diverse inputs based on which guidance can be generated and discuss different degrees of guidance and means to incorporate guidance into VA tools. We use existing guidance approaches from the literature to illustrate the various aspects of our model. As a conclusion, we identify research challenges and suggest directions for future studies. With our work we take a necessary step to pave the way to a systematic development of guidance techniques that effectively support users in the context of VA.

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Bernard, Jürgen; Dobermann, Eduard; Sedlmair, Michael; Fellner, Dieter W.

Combining Cluster and Outlier Analysis with Visual Analytics

2017

Sedlmaier, Michael (Ed.) et al.: EuroVA 2017 : EuroVis Workshop on Visual Analytics. Goslar: Eurographics Association, 2017, pp. 19-23

International EuroVis Workshop on Visual Analytics (EuroVA) <8, 2017, Barcelona, Spain>

Cluster and outlier analysis are two important tasks. Due to their nature these tasks seem to be opposed to each other, i.e., data objects either belong to a cluster structure or a sparsely populated outlier region. In this work, we present a visual analytics tool that allows the combined analysis of clusters and outliers. Users can add multiple clustering and outlier analysis algorithms, compare results visually, and combine the algorithms' results. The usefulness of the combined analysis is demonstrated using the example of labeling unknown data sets. The usage scenario also shows that identified clusters and outliers can share joint areas of the data space.

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CSG Ray Tracing Revisited: Interactive Rendering of Massive Models Made of Non-planar Higher Order Primitives

2017

Cláudio, Ana Paula (Ed.) et al.: GRAPP 2017. Proceedings : 12th International Conference on Computer Graphics Theory and Applications (VISIGRAPP 2017 Volume 1). SciTePress, 2017, pp. 258-265

International Conference on Computer Graphics Theory and Applications (GRAPP) <12, 2017, Porto, Portugal>

In many scientific and engineering areas, CAD models are constructed by combining simple primitives using Boolean set operations. Rendering such a dataset usually requires a preprocess, where the surface of the CAD model is approximated by an often highly complex triangle mesh. Real-time ray tracing provides an alternative to triangle rasterization as it allows for the direct visualization of (higher-order) solid and planar primitives without having to triangulate them. Additionally, Boolean compositing operations can be performed implicitly per ray, primitives have low storage requirements, and curved surfaces appear pixel-accurate. In this paper we demonstrate these properties using massive real-world CAD models.

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Braun, Andreas; Zander-Walz, Sebastian; Majewski, Martin; Kuijper, Arjan

Curved - Free-Form Interaction Using Capacitive Proximity Sensors

2017

Procedia Computer Science [online], Vol.109 (2017), pp. 59-66

International Conference on Ambient Systems, Networks and Technologies (ANT) <8, 2017, Madeira, Portugal>

Large interactive surfaces have found increased popularity in recent years. However, with increased surface size ergonomics become more important, as interacting for extended periods may cause fatigue. Curved is a large-surface interaction device, designed to follow the natural movement of a stretched arm when performing gestures. It tracks one or two hands above the surface, using an array of capacitive proximity sensors and supports both touch and mid-air gestures. It requires specific object tracking methods and the synchronized measurement from 32 sensors. We have created an example application for users wearing a virtual reality headset while seated that may benefit from haptic feedback and ergonomically shaped surfaces. A prototype with adaptive curvature has been created that allows us to evaluate gesture recognition performance and different surface inclinations.

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Vetter, Sven; Basgier, Dennis (Betreuer); Thöner, Maik (Betreuer)

Depth Image Based Composition in Distributed Rendering Environments

2017

Darmstadt, TU, Master Thesis, 2017

In dieser Arbeit wird ein auf Depth Image Based Rendering (DIBR) aufbauender Ansatz vorgestellt, der die flüssige Darstellung von Szenen auch auf leistungsschwächeren Geräten ermöglichen soll. Grundlage hierfür ist ein Client-Server Ansatz, bei dem der Server auf Anfrage Bilder zur Verfügung stellt, die der Client mit Hilfe von DIBR an seine Bedürfnisse anpasst. Außerdem wird ein Kameraprädiktor verwendet, um die Anfragen des Client zu optimieren. Die Qualität der erstellten Bilder wird mit Hilfe von drei verschiedenen Simulationen untersucht.

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Büttner, Sebastian; Mucha, Henrik; Funk, Markus; Kosch, Thomas; Aehnelt, Mario; Robert, Sebastian; Röcker, Carsten

The Design Space of Augmented and Virtual Reality Applications for Assistive Environments in Manufacturing: A Visual Approach

2017

Association for Computing Machinery (ACM): Proceedings of the 10th International Conference on PErvasive Technologies Related to Assistive Environments : PETRA 2017. New York: ACM, 2017. (ACM International Conference Proceedings Series (ICPS) 448), pp. 433-440

ACM International Conference on PErvasive Technologies Related to Assistive Environments (PETRA) <10, 2017, Island of Rhodes, Greece>

Research on how to take advantage of Augmented Reality and Virtual Reality applications and technologies in the domain of manufacturing has brought forward a great number of concepts, prototypes, and working systems. Although comprehensive surveys have taken account of the state of the art, the design space of industrial augmented and virtual reality keeps diversifying. We propose a visual approach towards assessing this space and present an interactive, community-driven tool which supports interested researchers and practitioners in gaining an overview of the aforementioned design space. Using such a framework we collected and classified relevant publications in terms of application areas and technology platforms. This tool shall facilitate initial research activities as well as the identification of research opportunities. Thus, we lay the groundwork, forthcoming workshops and discussions shall address the refinement.

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Khan, Zaheer; Dambruch, Jens; Peters-Anders, Jan; Sackl, Andreas; Strasser, Anton; Fröhlich, Peter; Templer, Simon; Soomro, Kamran

Developing Knowledge-Based Citizen Participation Platform to Support Smart City Decision Making: The Smarticipate Case Study

2017

Information, Vol.8 (2017), 2, 24 p.

Citizen participation for social innovation and co-creating urban regeneration proposals can be greatly facilitated by innovative IT systems. Such systems can use Open Government Data, visualise urban proposals in 3D models and provide automated feedback on the feasibility of the proposals. Using such a system as a communication platform between citizens and city administrations provides an integrated top-down and bottom-up urban planning and decision-making approach to smart cities. However, generating automated feedback on citizens' proposals requires modelling domain-specific knowledge i.e., vocabulary and rules, which can be applied on spatial and temporal 3D models. This paper presents the European Commission funded H2020 smarticipate project that aims to achieve the above challenge by applying it on three smart cities: Hamburg, Rome and RBKC-London. Whilst the proposed system architecture indicates various innovative features, a proof of concept of the automated feedback feature for the Hamburg use case 'planting trees' is demonstrated. Early results and lessons learned show that it is feasible to provide automated feedback on citizen-initiated proposals on specific topics. However, it is not straightforward to generalise this feature to cover more complex concepts and conditions which require specifying comprehensive domain languages, rules and appropriate tools to process them. This paper also highlights the strengths of the smarticipate platform, discusses challenges to realise its different features and suggests potential solutions.

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Bidarahalli, Suman; Kuijper, Arjan (Betreuer); Brunton, Alan (Betreuer)

A Distributed 3D Print Driver

2017

Darmstadt, TU, Master Thesis, 2017

Determining material arrangements to control high-resolution multi-material 3D printers for reproducing shape and visual attributes of a 3D model (e.g. spatially-varying color, translucency and gloss) requires large computational effort. Today's resolution and print tray sizes allow prints with more than 1012 voxels each filled with one of the available printing materials (today up to 7 materials can be combined in a single print). Cuttlefish, a 3D printing pipeline, processes the input in a serial fashion leading to increased computation time for higher number of models. Distributed computing is one way of achieving better performance for large computations. Through this master thesis, we have developed a distributed version of the cuttlefish printer driver in which the computational task is distributed amongst multiple nodes in the cluster and the resulting partial output is merged to generate the full slices. The architecture supports streaming, which is required to rapidly start the print before the full computation is finished, as cuttlefish processes the input in small parts and generates chunk-wise output. Finally, the comparison of the performance achieved by the distributed vs the non-distributed cuttlefish version is established to get a better understanding of the advantages and the challenges of distributed computing.

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E-Textile Couch: Towards Smart Garments Integrated Furniture

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 214-224

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Application areas like health-care and smart environments have greatly benefited from embedding sensors into every-day-objects, enabling for example sleep apnea detection. We propose to further integrate parts of sensors into the very own materials of the objects. Thus, in this work we explore integrating smart garments into furniture using a couch as our use-case. Equipped with textile capacitive sensing electrodes, we show that our prototype outperforms existing systems achieving an F-measure of 94.1%. Furthermore, we discuss implications and limitation of the integration process.

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Matthies, Denys J.C.; Strecker, Bernhard A.; Urban, Bodo

EarFieldSensing: A Novel In-Ear Electric Field Sensing to Enrich Wearable Gesture Input through Facial Expressions

2017

Mark, Gloria (Ed.) et al.: CHI '17. Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems. New York: ACM Press, 2017, pp. 1911-1922

Conference on Human Factors in Computing Systems (CHI) <35, 2017, Denver, CO, USA>

EarFieldSensing (EarFS) is a novel input method for mobile and wearable computing using facial expressions. Facial muscle movements induce both electric field changes and physical deformations, which are detectable with electrodes placed inside the ear canal. The chosen ear-plug form factor is rather unobtrusive and allows for facial gesture recognition while utilizing the close proximity to the face. We collected 25 facial-related gestures and used them to compare the performance levels of several electric sensing technologies (EMG, CS, EFS, EarFS) with varying electrode setups. Our developed wearable fine-tuned electric field sensing employs differential amplification to effectively cancel out environmental noise while still being sensitive towards small facial-movement-related electric field changes and artifacts from ear canal deformations. By comparing a mobile with a stationary scenario, we found that EarFS continues to perform better in a mobile scenario. Quantitative results show EarFS to be capable of detecting a set of 5 facial gestures with a precision of 90% while sitting and 85.2% while walking. We provide detailed instructions to enable replication of our low-cost sensing device. Applying it to different positions of our body will also allow to sense a variety of other gestures and activities.

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Efficient Compression for Server-Side G-Buffer Streaming in Web Applications

2017

ACM SIGGRAPH: Proceedings Web3D 2017 : 22nd International Conference on 3D Web Technology. New York: ACM, 2017, 7 p.

International Conference on 3D Web Technology (WEB3D) <22, 2017, Brisbane, Australia>

Remote rendering methods enable devices with low computing power like smart phones or tablets to visualize massive data. By transmitting G-Buffers, Depth-Image-Based Rendering (DIBR) methods can be used to compensate the artefacts caused by the latency. However, the drawback is that a G-Buffer has at least twice as much data as an image. We present a method for compressing G-Buffers which provides an efficient decoding suitable for web applications. Depending on the computing power of the device, software methods, which run on the CPU, may not be fast enough for an interactive experience. Therefore, we developed a decoding which runs entirely on the GPU. As we use only standard WebGL for our implementation, our compression is suitable for every modern browser.

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Efficient, Accurate, and Rotation-Invariant Iris Code

2017

IEEE Signal Processing Letters, Vol.24 (2017), 8, pp. 1233-1237

The large scale of the recently demanded biometric systems has put a pressure on creating a more efficient, accurate, and private biometric solutions. Iris biometrics is one of the most distinctive and widely used biometric characteristics. High-performing iris representations suffer from the curse of rotation inconsistency. This is usually solved by assuming a range of rotational errors and performing a number of comparisons over this range, which results in a high computational effort and limits indexing and template protection. This work presents a generic and parameter-free transformation of binary iris representation into a rotation-invariant space. The goal is to perform accurate and efficient comparison and enable further indexing and template protection deployment. The proposed approach was tested on a database of 10 000 subjects of the ISYN1 iris database generated by CASIA. Besides providing a compact and rotational-invariant representation, the proposed approach reduced the equal error rate by more than 55% and the computational time by a factor of up to 44 compared to the original representation.

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Joshi, Dhanashree Jayant; Kuijper, Arjan (Betreuer); Rus, Silvia (Betreuer)

Emotion Detection By Evaluating Activities For Smart Home Appliances

2017

Darmstadt, TU, Master Thesis, 2017

Human computer interactions can be made easier if we make computers understand person's emotions. Over the years, research in emotion recognition has mainly focused on facial expressions, voice analysis and hand-writing. Apart from these conventional methods, body movements, body postures and gestures or quality of movements can also be used to differentiate basic or fundamental emotions like happiness, anger, fear, sadness, surprise etc. For instance in case of fear, body of a person contracts, muscles tighten while as in case of happiness, muscles are more relaxed and body tends to occupy more area. Recognizing emotions of a person solely on his movements will enable efficient communication between human and machine. This master thesis is based on this idea of the machine being able to recognize the emotions from postures and movements of a human. A couch as a smart furniture has been used for the prediction of postures which are further used to predict the fundamental emotions including anxiety, happiness, sadness, relaxation, being focused/interested by using capacitive proximity sensors integrated into the couch. Android application was developed to predict the real-time postures of a person using machine learning classification algorithms. A relation between postures and movements with emotions has been established. This relation was considered as a baseline for the prediction of emotions. For the recognition of mentioned emotions, the detected movements and postures were analyzed and evaluated using various classification algorithms in machine learning. Furthermore the comparison of these classification algorithms with respect to performance was done and the better accuracy classification algorithm was chosen. This thesis also discusses in depth various methods that have been used to evoke the emotions of a human being during evaluation experiments. After successful evoking and prediction of the emotions, the results can then be used in various smart home applications.

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Enabling an Internet of Things Framework for Ambient Assisted Living

2017

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 9. AAL-Kongress 2016 Frankfurt/M. Springer International Publishing, 2017. (Advanced Technologies and Societal Change), pp. 181-196

Ambient Assisted Living (AAL) <9, 2016, Frankfurt, Germany>

Ambient Assisted Living (AAL) technologies hold great potential to meet the challenges of health, support, comfort and social services in European countries. After years of research, innovation and development in the field of health care and life support, there is still a lack of good practices on how to improve the market uptake of AAL solutions, how to commercialize laboratory results and prototypes and achieve widely accepted mature solutions with a significant footprint in the European market. The Internet of Things (IoT) consists of Internet connected objects such as sensors and actuators, as well as Smart appliances. Due to its characteristics, requirement and impact on real life system, the IoT has gained significant attention over the last few years. The major goal of this paper is to strategically specify and demonstrate the impact of the usage of IoT technology and the respect of IoT specification on the quality and future collaborative usage and extendability of deployed AAL solutions in real life.

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Rus, Silvia; Große-Puppendahl, Tobias; Kuijper, Arjan

Evaluating the Recognition of Bed Postures Using Mutual Capacitance Sensing

2017

Journal of Ambient Intelligence and Smart Environments, Vol.9 (2017), 1, pp. 113-127

Capacitive sensing is increasingly used to gather contextual information about humans. They can be used to create stationary or mobile systems for non-contact activity recognition. They are able to sense any conductive objects at distances up to 50 cm. This paper investigates an approach to classify bed postures using mutual capacitance sensing. The goal is to develop a system that prevents decubitus ulcers, which is a condition caused by prolonged pressure on the skin that can result in injuries to the skin and underlying tissues. The posture recognition is used to detect prolonged lying in a single pose and can notify care personnel. A low-cost grid of crossed wires is proposed that is placed between the mattress and the bed sheet that creates 48 measurement points. The experiments analyze a set of five bedding positions with 14 users. Using self-defined features, we achieved an accuracy of 80.8% for all users and an accuracy of 93.8% for individuals of similar body size. Refining the classification approach by directly classifying the raw data an overall accuracy of 90.5% was reached. By introducing an uncertainty threshold the classification is correct in 97.6% of cases.

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Raudaschl, Patrik F.; Zaffino, Paolo; Spadea, Maria Francesca; Chen, Antong; Dawant, Benoit M.; Albrecht, Thomas; Gass, Tobias; Langgut, Christoph; Lüthi, Marcel; Jung, Florian; Knapp, Oliver; Wesarg, Stefan; Mannion-Haworth, Richard; Bowes, Mike; Ashman, Annaliese; Guillard, Gwenael; Brett, Alan; Vincent, Graham; Orbes-Arteaga, Mauricio; Cárdenas-Peña, David; Castellanos-Dominguez, German; Aghdasi, Nava; Li, Yangming; Berens, Angelique; Moe, Kris; Hannaford, Blake; Schubert, Rainer; Fritscher, Karl D.

Evaluation of Segmentation Methods on Head and Neck CT: Auto-segmentation Challenge 2015

2017

Medical Physics, Vol.44 (2017), 5, pp. 2020-2036

Purpose Automated delineation of structures and organs is a key step in medical imaging. However, due to the large number and diversity of structures and the large variety of segmentation algorithms, a consensus is lacking as to which automated segmentation method works best for certain applications. Segmentation challenges are a good approach for unbiased evaluation and comparison of segmentation algorithms. Methods In this work, we describe and present the results of the Head and Neck Auto-Segmentation Challenge 2015, a satellite event at the Medical Image Computing and Computer Assisted Interventions (MICCAI) 2015 conference. Six teams participated in a challenge to segment nine structures in the head and neck region of CT images: brainstem, mandible, chiasm, bilateral optic nerves, bilateral parotid glands, and bilateral submandibular glands. Results This paper presents the quantitative results of this challenge using multiple established error metrics and a well-defined ranking system. The strengths and weaknesses of the different auto-segmentation approaches are analyzed and discussed. Conclusions The Head and Neck Auto-Segmentation Challenge 2015 was a good opportunity to assess the current state-of-the-art in segmentation of organs at risk for radiotherapy treatment. Participating teams had the possibility to compare their approaches to other methods under unbiased and standardized circumstances. The results demonstrate a clear tendency toward more general purpose and fewer structure-specific segmentation algorithms.

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An Exploratory Study on Electric Field Sensing

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 247-262

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Electric fields are influenced by the human body and other conducting materials. Capacitive measurement techniques are used in touch-screens, in the automobile industry, and for presence and activity recognition in Ubiquitous Computing. However, a drawback of the capacitive technology is the energy consumption, which is an important aspect for mobile devices. In this paper we explore possible applications of electric field sensing, a purely passive capacitive measurement technique, which can be implemented with an extremely low power consumption. To cover a wide range of applications, we examine five possible use cases in more detail. The results show that the application is feasible both in interior spaces and outdoors. Moreover, due to the low energy consumption, mobile usage is also possible.

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Dimitrov, Kristiyan; Kuijper, Arjan (Betreuer); Damer, Naser (Betreuer)

Exploring Deep Multi-biometric Fusion

2017

Darmstadt, TU, Master Thesis, 2017

The field of biometrics aims at performing automatic recognition of individuals based on their biological traits and is, hence, increasingly applied in places with high security requirements. To make biometric systems truly robust and reliable, multiple biometric sources could be combined with a particular fusion scheme. Mainly due to its ease of access, score-level fusion is the most practical method of multi-biometric fusion and has, thus, received the most attention from the research community. Higher-level fusion schemes (e.g. data or feature), in contrast, are difficult to achieve in practice. Yet, they are expected to yield superior results, owing to the higher amount of information available at the point of fusion. A central problem with this type of fusion is the extraction of a discriminative joint feature set. Feature extractors have to be manually designed and typically require a great deal of technical knowledge; for many tasks it is also infeasible to find an appropriate solution. Deep learning offers the ability to automatically learn useful features from raw data for any particular task with minimal human intervention. As a result, it is considered a reasonable option for realizing fusion in a multi-biometric scenario. Within the scope of this work, several architectures, based on a convolutional neural network model, are considered. Their performance have been tested in a multi-modal and a multiinstance setup, respectively. The results have been compared against baseline score-level fusion solutions. It has been shown, that with comparable network structures and computational costs, the less sophisticated, score-level fusion approach performs better than utilizing deep learning for the multi-biometric fusion process. As a future outlook, this thesis proposes possible modifications to the deep fusion approach that might improve the overall performance.

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Siegmund, Dirk; Samartzidis, Timotheos; Fu, Biying; Braun, Andreas

Fiber Defect Detection of Inhomogeneous Voluminous Textiles

2017

Carrasco-Ochoa, Jesús Ariel (Ed.) et al.: Pattern Recognition : MCPR 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10267), pp. 278-287

Mexican Conference on Pattern Recognition (MCPR) <9, 2017, Huatulco, Mexico>

Quality assurance of dry cleaned industrial textiles is still a mostly manually operated task. In this paper, we present how computer vision and machine learning can be used for the purpose of automating defect detection in this application. Most existing systems require textiles to be spread flat, in order to detect defects. In contrast, we present a novel classification method that can be used when textiles are in inhomogeneous, voluminous shape. Normalization and classification methods are combined in a decision-tree model, in order to detect different kinds of textile defects. We evaluate the performance of our system in realworld settings with images of piles of textiles, taken using stereo vision. Our results show, that our novel classification method using key point pre-selection and convolutional neural networks outperform competitive methods in classification accuracy.

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Roth, Daniel; Weber, Daniel (Betreuer)

The Finite Element Method for Nonlinear Elasticity in the Field of Computer Graphics

2017

Darmstadt, TU, Studienarbeit, 2017

In this survey different approaches for the simulation of nonlinear elastic behavior of objects were analyzed. The necessary physical background to understand where those nonlinearities emerge as well as the fundamentals of the linear and corotational FEM were presented. Then, different solution concepts for the nonlinear equations from the literature were introduced and analyzed w.r.t. computer graphics criteria. The advantages and disadvantages of each approach was shown in a side by side comparison. Furthermore, situations when each approach could find use were discussed.

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Adam, Meike; Tennstedt, Pierre; Lanwehr, Dominik; Tilki, Derya; Steuber, Thomas; Beyer, Burkhard; Thederan, Imke; Heinzer, Hans; Haese, Alexander; Salomon, Georg; Budäus, Lars; Michl, Uwe; Pehrke, Dirk; Stattin, Pär; Bernard, Jürgen; Klaus, Bernd; Pompe, Raisa S.; Petersen, Cordula; Huland, Hartwig; Graefen, Markus; Schwarz, Rudolf; Huber, Wolfgang; Loeb, Stacy; Schlomm, Thorsten

Functional Outcomes and Quality of Life After Radical Prostatectomy Only Versus a Combination of Prostatectomy with Radiation and Hormonal Therapy

2017

European Urology, Vol.71 (2017), 3, pp. 330-336

Background: While the optimal use and timing of secondary therapy after radical prostatectomy (RP) remain controversial, there are limited data on patient-reported outcomes following multimodal therapy. Objective: To assess the impact of additional radiation therapy (RT) and/or androgen deprivation therapy (ADT) on urinary continence, potency, and quality of life (QoL) after RP. Design, setting, and participants: Among 13 150 men who underwent RP from 1992 to 2013, 905 received RP + RT, 407 RP + ADT and 688 RP + RT + ADT. Outcome measurements and statistical analyses: Urinary function, sexual function, and overall QoL were evaluated annually using self-administered validated questionnaires. Propensity score-matched and bootstrap analyses were performed, and the distributions for all functional outcomes were analyzed as a function of time after RP. Results and limitations: Patients who received RP + RT had a 4% higher overall incontinence rate 3 yr after surgery, and 1% higher rate for severe incontinence (>3 pads/24 h) compared to matched RP-only patients. ADT further increased the overall and severe incontinence rates by 4% and 3%, respectively, compared to matched RP + RT patients. RP + RT was associated with an 18% lower rate of potency compared to RP alone, while RP + RT + ADT was associated with a further 17% reduction compared to RP + RT. Additional RT reduced QoL by 10% and additional ADT by a further 12% compared to RP only and RP + RT, respectively. The timing of RT after RP had no influence on continence, but adjuvant compared to salvage RT was associated with significantly lower potency (37% vs 45%), but higher QoL (60% vs 56%). Limitations of our study include the observational study design and potential for selection bias in the treatments received. Conclusions: Secondary RT and ADT after RP have an additive negative influence on urinary function, potency, and QoL. Patients with high-risk disease should be counseled before RP on the potential net impairment of functional outcomes due to multimodal treatment. Patient summary: Men with high-risk disease choosing surgery upfront should be counseled on the potential need for additional radiation and or androgen deprivation, and the potential net impairment of functional outcomes arising from multimodal treatment.

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General Borda Count for Multi-biometric Retrieval

2017

IEEE Computer Society: 2017 International Joint Conference on Biometrics : IJCB 2017. IEEE Computer Society Conference Publishing Services (CPS), 2017, pp. 420-428

IEEE International Joint Conference on Biometrics (IJCB) <2017, Denver, CO, USA>

Indexing of multi-biometric data is required to facilitate fast search in large-scale biometric systems. Previous works addressing this issue were challenged by including biometric sources of different nature, utilizing the knowledge about the biometric sources, and optimizing and tuning the retrieval performance. This work presents a generalized multi-biometric retrieval approach that adapts the Borda count algorithm within an optimizable structure. The approach was tested on a database of 10k reference and probe instances of the left and the right irises. The experiments and comparisons to five baseline solutions proved to achieve advances in terms of general indexing performance, tunability to certain operating points, and response to missing data. A clear advantage of the proposed solution was noticed when faced by candidate lists of low quality.

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Go-3D 2017: Mit 3D Richtung Maritim 4.0: Tagungsband zur Konferenz Go-3D 2017

2017

Go-3D <8, 2017, Rostock, Germany>

Die Konferenz Go-3D 2017 präsentiert aktuelle Forschungsergebnisse der 3D-Computergraphik sowie deren praktische Einsatzmöglichkeiten in der Industrie. Fachexperten aus Wissenschaft und Wirtschaft spannen in ihren Beiträgen ein breites Spektrum von der 3D-Erfassung über die Erstellung maritimer 3D-Applikationen bis zu virtuellen Trainingsumgebungen. Highlights sind in diesem Jahr Vorträge über 3D-basierte Engineering-Kollaboration, Simulation und Visualisierung aus der Cloud und das Kraken SeaVision System zur 3D-Bildgebung unter Wasser. Veranstalter der Konferenz ist das Kompetenznetzwerk "Go-3D S Effiziente Prozesskette für 3D-Computergraphik".

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Frank, Sebastian; Kuijper, Arjan

HUDConCap - Automotive Head-Up Display Controlled with Capacitive Proximity Sensing

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 197-213

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Most of the current Head-Up Display solutions in the automotive domains can not handle user input. Nevertheless, many automotive manufacturers develop and/or implement gesture interaction systems, controlled by the user's hand, into their head-down infotainment displays. The gesture recognition, precisely the hand tracking, is mostly facilitated with camera systems that monitor the driver or with infrared sensors. These systems require a line of sight between the driver's hands and the measurement transducer. Therefore, they require interior design integration and are visible to the user. Moreover, the permanent camera monitoring of the driver, in combination with an internet connected vehicle, can cause privacy issues and increase the driver's feeling of observation. We therefore present a system that integrates user control into a Head-Up Display, similar to a computer mouse. Moreover, the presented system's capacitive proximity sensors can sense through non-conductive materials. Thus, the system can be invisibly integrated into existing vehicle structures. In our case, it is part of the steering wheel. With our presented system, vehicle manufactures are able to install a Head-Up display control system without any visible design changes. Furthermore, the manufacturer provides more interaction space in driving situations. Additionally, he can rely on the lower level of driver distraction provided by Head-Up displays. Therefore, the presented system can increase driving safety. The systems usability is shown by a small user-study that consists of performance tests on a proof-of-concept prototype and a questionnaire.

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Implicit Mesh Generation Using Volumetric Subdivision

2017

Jaillet, Fabrice (Ed.) et al.: VRIPHYS 17: 13th Workshop in Virtual Reality Interactions and Physical Simulations. Goslar: Eurographics Association, 2017, pp. 9-19

International Workshop in Virtual Reality Interaction and Physical Simulations (VRIPHYS) <13, 2017, Lyon, France>

In this paper, we present a novel approach for a tighter integration of 3D modeling and physically-based simulation. Instead of modeling 3D objects as surface models, we use a volumetric subdivision representation. Volumetric modeling operations allow designing 3D objects in similar ways as with surface-based modeling tools. Encoding the volumetric information already in the design mesh drastically simplifies and speeds up the mesh generation process for simulation. The transition between design, simulation and back to design is consistent and computationally cheap. Since the subdivision and mesh generation can be expressed as a precomputable matrix-vector multiplication, iteration times can be greatly reduced compared to common modeling and simulation setups. Therefore, this approach is especially well suited for early-stage modeling or optimization use cases, where many geometric changes are made in a short time and their physical effect on the model has to be evaluated frequently. To test our approach, we created, simulated and adapted several 3D models. Additionally, we measured and evaluated the timings for generating and applying the matrices for different subdivision levels. For comparison, we also measured the tetrahedral meshing functionality offered by CGAL for similar numbers of elements. For changing topology, our implicit meshing approach proves to be up to 70 times faster than creating the tetrahedral mesh only based on the outer surface. Without changing the topology and by precomputing the matrices, we achieve a speed-up of up to 2800.

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Gladisch, Stefan; Ruth, Thomas; Jonas, Mathias

Improving Uncertainty Visualization in ENCs: Towards a Better Portrayal of Bathymetric Data Quality for Mariners

2017

Hydro International, Vol.21 (2017), 2, pp. 14-17

The visualization of bathymetric data and associated uncertainty in electronic nautical charts is important when it comes to plan and monitor a ship's route safely. However, a study confirmed that the current uncertainty representation is not very intuitive and does not provide clear orientation for mariners. To improve this situation, Fraunhofer IGD proposed novel visualization solutions for the next generation S-101 ENC standard, which are summarized in this article.

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Terhörst, Philipp; Walther, Thomas (Betreuer); Braun, Andreas (Betreuer); Damer, Naser (Betreuer)

Indexing of Multi-biometric Databases: Fast and Accurate Biometric Search

2017

Darmstadt, TU, Master Thesis, 2017

Biometrics is a rapidly developing field of research and biometric-based identification systems experience a massive growth all around the world caused by the gaining industrial, government and citizen acceptance. The US-VISIT program uses biometric systems to enforce homeland and border security, whereas in the United Arab Emirates (UAE), biometric systems play a major role in the border control process. Similar, in India, biometrics have gained a great deal of attention, as the Unique Identification Authority of India (UIDAI) have already registered over one billion Indian citizens in the last 7 years (uidai.gov.in). Despite the rapid propagation of large-scale databases, the majority of researchers are still focusing on the matching accuracy of small databases, while neglecting scalability and speed issues. Identity association is usually determined by comparing input data against every entry in the database, which causes computational problems when it comes to large-scale databases. Biometric indexing aims to reduce the number of candidate identities to be considered by an identification system when searching for a match in large biometric databases. However, this is a challenging task since biometric data is fuzzy and does not exhibit any natural sorting order. Current indexing methods are mainly based on tree traversal (using kd-trees, B-trees, R-trees) which suffer from the curse of dimensionality, while other indexing methods are based on hashing, which suffer from pure key generation. The goal of this thesis is to develop an indexing scheme based on multiple biometric modalities. It aims to present the main results of research focusing on iris and fingerprint indexing. Fingerprints are undisputedly the most studied biometric modality that are extensive used in civil and forensic recognition systems. Together with the potential rise of iris recognition accurateness along with enhanced robustness, indexing of this modalities becomes a promising field of research. Different unimodal and multimodal identification approaches have already been proposed in past years. However, most of them trade fast identification rates at the cost of accuracy, while the remaining make use of complex indexing structures, which results in a complete restructuring if insertions or deletions are necessary. This work offers a framework for fast and accurate iris indexing as well as effective indexing schemes to combine multiple modalities. To achieve that, three main contributions are made: First, a new rotation invariant iris representation was developed, reducing the equal error rate by more than 55% and the computation time by a factor up to 44 compared to the original representation. Second, this representation was used to construct an indexing scheme, which reaches a hit rate of 99.7% at 0.1% penetration rate, outperforming state of the art algorithms. And third, a general rank-level indexing fusion scheme was developed to effectively combine multiple sources, achieving over 99.98% hit rate at same penetration rate of 0.1%.

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Indexing of Single and Multi-instance Iris Data Based on LSH-Forest and Rotation Invariant Representation

2017

Felsberg, Michael (Ed.) et al.: Computer Analysis of Images and Patterns : CAIP 2017 Proceedings, Part II. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10425), p. 190-201

International Conference on Computer Analysis of Images and Patterns (CAIP) <17, 2017, Ystad, Sweden>

Indexing of iris data is required to facilitate fast search in large-scale biometric systems. Previous works addressing this issue were challenged by the tradeoffs between accuracy, computational efficacy, storage costs, and maintainability. This work presents an iris indexing approach based on rotation invariant iris representation and LSH-Forest to produce an accurate and easily maintainable indexing structure. The complexity of insertion or deletion in the proposed method is limited to the same logarithmic complexity of a query and the required storage grows linearly with the database size. The proposed approach was extended into a multi-instance iris indexing scheme resulting in a clear performance improvement. Single iris indexing scored a hit rate of 99.7% at a 0.1% penetration rate while multi-instance indexing scored a 99.98% hit rate at the same penetration rate. The evaluation of the proposed approach was conducted on a large database of 50k references and 50k probes of the left and the right irises. The advantage of the proposed solution was put into prospective by comparing the achieved performance to the reported results in previous works.

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Indoor Localization Based on Passive Electric Field Sensing

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 64-79

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

The ability to perform accurate indoor positioning opens a wide range of opportunities, including smart home applications and location-based services. Smart floors are a well-established technology to enable marker-free indoor localization within an instrumented environment. Typically, they are based on pressure sensors or varieties of capacitive sensing. These systems, however, are often hard to deploy as mechanical or electrical features are required below the surface. They might also have a limited range or not be compatible with different floor materials. In this paper, we present a novel indoor positioning system using an uncommon form of passive electric field sensing, which detects the change in body electric potential during movement. It is easy to install by deploying a grid of passive wires underneath any non-conductive floor surface. The proposed architecture achieves a high position accuracy and an excellent spatial resolution. In our evaluation, we measure a mean positioning error of only 12.7 cm. The proposed system also combines the advantages of very low power consumption, easy installation, easy maintenance, and the preservation of privacy.

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Lindig, Tom; Urban, Bodo (Betreuer); Müller, Andreas (Betreuer); Diener, Holger (Betreuer)

Informationsvisualisierung im Gesundheitswesen

2017

Rostock, Univ., Bachelor Thesis, 2017

Krankenhausinformationssysteme setzen sich heutzutage meist aus Modulen verschiedener Hersteller zusammen. Gleichzeitig steigen die Anforderungen an Qualität und Optimierung des Krankenhausaufenthaltes. Auf Basis der Engine Unity3D wird eine Visualisierungssoftware entwickelt, die Informationen aus verschiedenen Teilbereichen des Krankenhausinformationssystems zusammenführt und einheitlich darstellt. Mithilfe eines 3D-Modells des Krankenhauses wird ein Ortsbezug zu den Daten hergestellt.

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Patzwahl, Alex; Kuijper, Arjan (Betreuer); Brodkorb, Felix (Betreuer)

Interaktives Erzeugen von dynamischen geographischen Netzwerken

2017

Darmstadt, TU, Bachelor Thesis, 2017

Graphen finden in den unterschiedlichsten Gebieten Anwendung. Neben vielen anderen Eigenschaften besitzen diese auch oft einen geographischen Kontext. Beispielsweise Computernetzwerke, bei denen die einzelnen Computer über geographische Standorte verfügen. Diese Besonderheit ist keinesfalls unwichtig, da sie zusätzliche Informationen bergen kann. Ebenfalls ist es sehr wahrscheinlich, dass sich diese Netzwerke auch über die Zeit entwickeln. Zur genaueren Analyse der Netzwerke werden folglich einige Daten benötigt, welche aber nur in geringen Mengen frei zur Verfügung stehen. Genauso werden auch größere, vielfältigere Datenmengen zu Test- oder Simulationszwecken gebraucht, die kaum zu finden sind. Deswegen bedarf es an dieser Stelle an Wegen zur künstlichen Generierung dieser Daten. In dieser Arbeit wird ein interaktiv, visuelles Generatormodel zur Erzeugung von dynamisch geographischen Netzwerken präsentiert. Dabei wird der Benutzer beim Steuern des Generierungsprozesses durch einen Wizard geführt, um die Bedienung zu erleichtern. Der eigentliche Algorithmus hinter dem Generator arbeitet zum Teil auf Power-Law Basis sowie auf weiteren, in dieser Arbeit präsentierten analytischen Ergebnissen.

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Hartl, Tabea; Kuijper, Arjan (Betreuer); Jung, Florian (Betreuer)

Ein interaktives Segmentierungsverfahren für Strukturen in medizinischen Bilddaten unter Verwendung eines Random Walk Ansatzes

2017

Darmstadt, TU, Bachelor Thesis, 2017

Tumore im Kopf-Hals-Bereich stellen eine gefährliche invasive Krankheit dar, daher ist eine ausführliche Diagnose und Therapieplanung für den Patienten von großer Bedeutung. Ein wichtiger Teil dieser Diagnose und Therapieplanung ist die Segmentierung des Tumors. Häufig werden hierzu Bilddaten verwendet, die mit Hilfe der Magnetresonanztomographie aufgenommen wurden. Für diesen speziellen Anwendungsfall gibt es aktuell kein Verfahren, dass gute Ergebnisse liefert. Diese Arbeit stellt einen interaktiven Segmentierungsalgorithmus für Tumore im Kopf-Hals-Bereich vor, der einen Random Walk Ansatz nutzt. Der Algorithmus verwendet initiale Markierungen um eine Segmentierung von Tumoren zu erstellen, auch wenn Strukturen mit ähnlichen Intensitätswerten angrenzen. Aus Effizienzgründen wird die Ähnlichkeit zu einem Problem aus der Schaltungstheorie ausgenutzt. Dafür werden die Bilddaten in eine Graphendarstellung überführt, die aus Knoten und gewichteten Kanten besteht. Ausgehend von dieser Darstellung wird ein lineares Gleichungssystem aufgestellt, welches die Lösung des Random Walk Ansatzes berechnet. Der Algorithmus liefert in MR-Daten für Tumore im Kopf-Hals-Bereich gute Ergebnisse. Wir haben den Algorithmus für 18 verschiedene Tumore und jeweils zwei unterschiedliche initiale Markierungen getestet. Der Median der Hausdorff-Distanz aller Segmentierungen liegt bei einem Wert von 8,83 und der Dice-Koeffizient bei einem Wert von 0,71. Zusätzlich wurde der Ansatz auch auf CT-Daten für vier verschiedenen Strukturen und für Lymphknoten auf MR-Bildern evaluiert. Ein großer Vorteil des Verfahrens ist, die Möglichkeit Expertenwissen durch initiale Markierungen einfließen zu lassen und damit die Ergebnisse des Algorithmus zu verbessern. Dies erlauben die meisten andere Verfahren nicht. Der Algorithmus liefert nutzbare Segmentierungen für Tumore und Lymphknoten in MR-Bilddaten. Er ist generisch verwendbar und kann auch für andere Strukturen und Modalitäten genutzt werden.

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Invisible Human Sensing in Smart Living Environments Using Capacitive Sensors

2017

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 9. AAL-Kongress 2016 Frankfurt/M. Springer International Publishing, 2017. (Advanced Technologies and Societal Change), pp. 43-53

Ambient Assisted Living (AAL) <9, 2016, Frankfurt, Germany>

Smart living environments aim at supporting their inhabitants in daily tasks by detecting their needs and dynamically reacting accordingly. This generally requires several sensor devices, whose acquired data is combined to assess the current situation. Capturing the full range of situations necessitates many sensors. Often cameras and motion detectors are used, which are rather large and difficult to hide in the environment. Capacitive sensors measure changes in the electric field and can be operated through any non-conductive material. They gained popularity in research in the last few years, with some systems becoming available on the market. In this work we will introduce how those sensors can be used to sense humans in smart living environments, providing applications in situation recognition and human-computer interaction. We will discuss opportunities and challenges of capacitive sensing and give an outlook on future scenarios.

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Fellner, Dieter W.; Baier, Konrad; Ackeren, Janine van; Alexandrin, Max; Barth, Anna; Bockholt, Ulrich; Kopold, Franziska; Löwer, Chris; May, Thorsten; Peters, Wiebke; Wehner, Detlef; Gollnast, Anja; Bumke, Carina

Jahresbericht 2016: Fraunhofer-Institut für Graphische Datenverarbeitung IGD

2017

Das Fraunhofer IGD hat seine Forschungsaktivitäten vor Kurzem in vier Leitthemen gebündelt, welche die Basis seiner Arbeit bilden und verschiedene Themen abteilungsübergreifend miteinander verknüpfen. Eines dieser Leitthemen ist "Visual Computing as a Service - Die Plattform für angewandtes Visual Computing". Die Basis dieser universellen Plattform für Visual-Computing Lösungen ist gelegt und wird kontinuierlich erweitert. Dieser technologische Ansatz bildet die Grundlage für die weiteren Leitthemen. In der "Individuellen Gesundheit - Digitale Lösungen für das Gesundheitswesen" werden die Daten betrachtet, die in der personalisierten Medizin anfallen - mithilfe der Visual-Computing-Technologien des Instituts. Im Leitthema "Intelligente Stadt - Innovativ, digital und nachhaltig" ist die Fragestellung, wie man den Lebenszyklus urbaner Prozesse unterstützen kann. Und im Leitthema "Digitalisierte Arbeit - Der Mensch in der Industrie 4.0" geht es erster Linie um die Unterstützung des Menschen in der durch die Digitalisierung veränderten Produktion.

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Bockholt, Ulrich; Bochtler, Thomas; Enderlein, Volker; Olbrich, Manuel; Otto, Michael; Prieur, Michael; Sauerbier, Richard; Stechow, Roland; Wehe, Andreas; Wirsching, Hans-Joachim

Motion Capturing

2017

Schreiber, Werner (Ed.) et al.: Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie. Berlin: Springer Vieweg, 2017, pp. 219-262

Motion Capture Technologien werden in vielen unterschiedlichen Bereichen eingesetzt, wie zum Beispiel der Filmindustrie, der Sportrehabilitation, der Spieleentwicklung oder im industriellen Umfeld. Die Technologie ermöglicht es, Bewegungen aufzuzeichnen und diese auf eine digitale Repräsentanz (Avatar) eines Menschen (Digital Human Model) zu applizieren. Über ein generisches Menschmodell bzw. mit Hilfe der im Projekt ARVIDA entwickelten Referenzarchitektur ist eine universelle Anwendung möglich und verschiedene Expertensysteme lassen sich derart nutzen, dass ein ganzheitlicher Prozess durchgeführt werden kann. Für Ergonomie-Untersuchungen im Nutzfahrzeug können allgemein gültige digitale Bewegungsbausteine entwickelt werden, die sich nachträglich an neue, ähnliche Szenarien anpassen lassen. In der Produktionsabsicherung wird bereits in den frühen Phasen ein höherer Reifegrad ermöglicht, indem Motion Capturing für die Echtzeitsimulation von manuellen Arbeitsvorgängen in virtuellen Umgebungen eingesetzt wird.

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Wen, Zhuoman; Kuijper, Arjan; Fraissinet-Tachet, Matthieu; Wang, Yanjie; Luo, Jun

Mutual Information-Based Tracking for Multiple Cameras and Multiple Planes

2017

Arabian Journal for Science and Engineering, Vol.42 (2017), 8, pp. 3451-3463

Based onmutual information (MI), this paper proposes a systematic analysis of tracking a multi-plane object with multiple cameras. Firstly, a geometric model consisting of a piecewise planar object and multiple cameras is setup. Given an initial pose guess, the method seeks a pose update that maximizes the global MI of all the pairs of reference image and camera image. An object pose-dependent warp is proposed to ensure computation precision. Six variations of the proposed method are designed and tested. Mode 1, i.e., computing the 2nd-order Hessian of MI at each step as the object pose changes, leads to the highest convergence rates; Mode 2, i.e., computing the 1st-order Hessian of MI once at the beginning, occupies the least time (0.5-1.0 s). For objects with simple-textured planes, applying Gaussian blur first and then useMode 1 shall generate the highest convergence rate.

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Neighbor Distance Ratios and Dynamic Weighting in Multi-biometric Fusion

2017

Alexandre, Luís A. (Ed.) et al.: Pattern Recognition and Image Analysis : IbPRIA 2017. Springer International Publishing, 2017. (Lecture Notes in Computer Science (LNCS) 10255), pp. 491-500

Iberian Conference on Pattern Recognition and Image Analysis (IbPRIA) <8, 2017, Faro, Portugal>

Multi-biometrics aims at building more accurate unified biometric decisions based on the information provided by multiple biometric sources. Information fusion is used to optimize the process of creating this unified decision. In previous works dealing with score-level multibiometric fusion, the scores of different biometric sources belonging to the comparison of interest are used to create the fused score. This is usually achieved by assigning static weights for the different biometric sources. In contrast, we focus on integrating the information imbedded in the relative relation between the comparison scores (within a 1:N comparison) in the biometric fusion process using a dynamic weighting scheme. This is performed by considering the neighbors distance ratio in the ranked comparisons to influence the dynamic weights of the fused scores. The evaluation was performed on the Biometric Scores Set BSSR1 database. The enhanced performance induced by including the neighbors distance ratio information within a dynamic weighting scheme in comparison to the baseline solution was shown by an average reduction of the equal error rate by more than 40% over the different test scenarios.

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Großpersky, Steffen; Wiesmaier, Alexander (Betreuer); Stiemerling, Martin (Betreuer); Daun, Stefan (Betreuer)

Neukonzeption und Implementierung eines Drupal-Moduls für Publikationslisten

2017

Darmstadt, Hochschule, Bachelor Thesis, 2017

Die Veröffentlichung wissenschaftlicher Publikationen ist ein wesentliches Kennzeichen von Forschung. Nur wenn neu gewonnene Erkenntnisse dokumentiert und mit anderen geteilt werden, entsteht Wissen. Auch die Mitarbeiter des Fraunhofer-Instituts für Graphische Datenverarbeitung IGD veröffentlichen ihre Forschungsergebnisse jedes Jahr in zahlreichen wissenschaftlichen Publikationen. Bisher wurden die Publikationen auf der mit dem Content Management System Drupal realisierten Website des Instituts in verschiedenen Formen dargestellt. So wurden unter anderem auch auf den Webseiten der Mitarbeiter, deren jeweilige Veröffentlichungen für das Institut aufgelistet. Durch eine Umstellung der Website auf ein neues Design und eine neue Struktur, sowie durch eine kommende Umstellung des Bibliothekssystems, konnte die bisherige Lösung nicht mehr verwendet werden. Ziel dieser Bachelorarbeit ist deshalb die Neukonzeption und Implementierung einer Softwareerweiterung für Drupal, um die Publikationen der Mitarbeiter wieder auf der Website anzeigen zu können. Dabei sollen auch Verbesserungen in der Leistungsfähigkeit und der Kompatibilität mit unterschiedlichen Bibliothekssystemen erreicht werden. Für die Erstellung eines Konzepts wird zunächst eine Analyse bestehender Lösungen durchgeführt. Auf Basis der Analyse wird ein Konzept erstellt und dieses teilweise implementiert. Die implementierte Lösung wird im Anschluss mit der zuvor genutzten Lösung verglichen. In dieser Evaluation zeigt sich, dass die neu konzeptionierte Lösung deutlich leistungsfähiger und flexibler als die alte Lösung ist. Allerdings ist auch mit der neuen Lösung keine vollautomatische Zuordnung von Autorennamen zu Personen möglich, da zum einen unterschiedliche Schreibweisen für einen Namen verwendet werden, und zum anderen, weil sich der Name einer Person z.B. durch Heirat ändern kann.

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New Approach for Optimizing the Usage of Situation Recognition Algorithms Within IoT Domains

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 183-196

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

The growth of the Internet of Things (IoT) over the past few years enabled a lot of application domains. Due to the increasing number of IoT connected devices, the amount of generated data is increasing too. Processing huge amounts of data is complex due to the continuously running situation recognition algorithms. To overcome these problems, this paper proposes an approach for optimizing the usage of situation recognition algorithms in Internet of Things domains. The key idea of our approach is to select important data, based on situation recognition purposes, and to execute the situation recognition algorithms after all relevant data have been collected. The main advantage of our approach is that situation recognition algorithms will not be executed each time new data is received, thus allowing the reduction of the situation recognition algorithms execution frequency and saving computational resources.

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New Approaches for Localization and Activity Sensing in Smart Environments

2017

Wichert, Reiner (Ed.) et al.: Ambient Assisted Living : 9. AAL-Kongress 2016 Frankfurt/M. Springer International Publishing, 2017. (Advanced Technologies and Societal Change), pp. 73-84

Ambient Assisted Living (AAL) <9, 2016, Frankfurt, Germany>

Smart environments need to be able to fulfill the wishes of its occupants unobtrusively. To achieve this goal, it has to be guaranteed that the current state environment is perceived at all times. One of the most important aspects is to find the current position of the in- habitants and to perceive how they move in this environment. Numerous technologies enable such supervision. Particularly challenging are marker-free systems that are also privacy-preserving. In this paper, we present two such systems for localizing inhabitants in a Smart Environment using - electrical potential sensing and ultrasonic Doppler sensing. We present methods that infer location and track the user, based on the acquired sensor data. Finally, we discuss the advantages and challenges of these sensing technologies and provide an overview of future research directions.

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Dimitrov, Dimitar Tomov; Kuijper, Arjan (Betreuer)

Non-Local Bayes Denoising of Digital Images on GPU using OpenCL

2017

Darmstadt, TU, Master Thesis, 2017

Image sensors or lens inevitably produce a wide range of degradations in digital images. Among these degradations are various types of noise. Image noise is undesirable, random information added to the image that can cause significant quality degradation. Therefore, image denoising methods are very often the first step of an image processing chain. Non-Local Bayes (NL-Bayes) is a state of the art image denoising algorithm that provides effective noise reduction with good preservation of image details. Although efficient CPU implementations of this method exist, they still have performance issues. Nowadays, GPUs become a general-purpose computational devices and provide their power for more generalized tasks. Their massively parallel capabilities can significantly improve the performance of computationally expensive programs. However, due to the specific execution and memory model, algorithms for GPUs require special design that divides the computational task into as many independent pieces as possible. This thesis proposes solutions to perform NL-Bayes image denoising on the GPU using the OpenCL standard. Our study evaluates quantitatively and qualitatively the proposed implementations by making comparisons with an existing CPU implementation. We show that a GPU-based solution is six times faster compared to the CPU-based solution when maximal denoising quality is demanded. Additionally, we describe general problems in the parallelization of such a complex image denoising algorithm.

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Ma, Jingting; Wang, Anqi; Lin, Feng; Wesarg, Stefan; Erdt, Marius

Nonlinear Statistical Shape Modeling for Ankle Bone Segmentation Using a Novel Kernelized Robust PCA

2017

Descoteaux, Maxime (Ed.) et al.: Medical Image Computing and Computer Assisted Intervention - MICCAI 2017: Part I : 20th International Conference. Springer International Publishing, 2017. (Lecture Notes in Computer Science (LNCS) 10433), pp.136-143

International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI) <20, 2017, Quebec City, Canada>

Statistical shape models (SSMs) are widely employed in medical image segmentation. However, an inferior SSM will degenerate the quality of segmentations. It is challenging to derive an efficient model because: (1) often the training datasets are corrupted by noise and/or artifacts; (2) conventional SSM is not capable to capture nonlinear variabilities of a population of shape. Addressing these challenges, this work aims to create SSMs that are not only robust to abnormal training data but also satisfied with nonlinear distribution. As Robust PCA is an efficient tool to seek a clean low-rank linear subspace, a novel kernelized Robust PCA (KRPCA) is proposed to cope with nonlinear distribution for statistical shape modeling. In evaluation, the built nonlinear model is used in ankle bone segmentation where 9 bones are separately distributed. Evaluation results show that the model built with KRPCA has a significantly higher quality than other state-of-the-art methods.

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Nutzung von Stereo-Hochkontrast-Aufnahmen für eine bodengestützte, automatische Bestimmung von Schüttgutmaterialien und für die Erkennung der Belegung von Außenlagerflächen in Häfen

2017

Lukas, Uwe von (Ed.) et al.: Go-3D 2017: Mit 3D Richtung Maritim 4.0 : Tagungsband zur Konferenz Go-3D 2017. Stuttgart: Fraunhofer Verlag, 2017, pp. 157-166

Go-3D <8, 2017, Rostock, Germany>

In diesem Artikel wird ein Stereokameraaufbau vorgeschlagen, welcher es ermöglicht, über weite Distanzen einen Schüttguthaufen freizustellen und seine Art (Sand, Kies, Roheisen) zu bestimmen. Durch Aufnahme von Belichtungsreihen werden Hochkontrastbilder gewonnen. Somit ist das System für Außenaufnahmen bei jedem Wetter geeignet. Der vorgestellte Ansatz arbeitet in fünf Schritten: Aufnahme von Stereo- Hochkontrastbildern, Bildvorverarbeitung, Semi-global Blockmatching, Segmentierung/Rücktransformation und Materialerkennung. Es wird in diesem Artikel gezeigt, dass dieses Verfahren robust gegenüber Wetterbedingungen ist, eine zuverlässige Segmentierung auf Basis der Tiefeninformationen erreicht und die korrekte Materialbestimmung ermöglicht.

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Opportunities for Biometric Technologies in Smart Environments

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 175-182

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Smart environments describe spaces that are equipped with sensors, computing facilities and output systems that aim at providing their inhabitants with targeted services and supporting them in their tasks. Increasingly these are faced with challenges in differentiating multiple users and secure authentication. This paper outlines how biometric technologies can be applied in smart environments to overcome these challenges. We give an introduction to these domains and show various applications that can benefit from the combination of biometrics and smart environments.

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Ritter, Christian; Kuijper, Arjan (Betreuer); Bernard, Jürgen (Betreuer)

Personalized Music Classification and Feature Creation based on Visual-Interactive Learning

2017

Darmstadt, TU, Bachelor Thesis, 2017

I present an approach for personalized music classification and feature generation. Currently existing approaches cover general models that match the common taste of music and use (small) sets of pre-defined features. Allowing a user to interactively build a music classification model is a complex task. In this work, I introduce a two-level approach that utilizes Visual Analytics to solve that task. At high-level granularity, a user can interactively classify music in a visual interface. The system supports the user with multiple views that grant model insights and information about the feature space. Furthermore, the user can freely define classes and assign them to songs of his collection. At low-level granularity, a user is able to create features matching his task by defining important audio patterns. A similarity over the song is calculated from each pattern and then used to create features that depend on the preferences of the user. The approach I contribute allows classification of music (or, in general, multivariate time series) for various tasks with features created at run-time. Thus, it makes classification interactive and applicable to multiple tasks. Several evaluation techniques showed the usefulness of the approach in different scenarios and the effectiveness of personalized features.

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Edelsbrunner, Johannes; Havemann, Sven; Sourin, Alexei; Fellner, Dieter W.

Procedural Modeling of Architecture with Round Geometry

2017

Computers & Graphics, Vol.64 (2017), pp. 14-25

International Conference on Cyberworlds (CW) <2016, Chongqing, China>

Creation of procedural 3D building models can significantly reduce the costs of modeling, since it allows for generating a variety of similar shapes from one procedural description. The common field of appli- cation for procedural modeling is modeling of straight building facades, which are very well suited for shape grammars-a special kind of procedural modeling system. In order to generate round building geometry, we present a way to set up different coordinate systems in shape grammars. Besides Cartesian, these are primarily cylindrical and spherical coordinate systems for generation of structures such as towers or domes, that can procedurally adapt to different dimensions and parameters. The users can apply common splitting idioms from shape grammars in their familiar way for creating round instead of straight geometry. The second enhancement we propose is to provide a way for users to give high level inputs that are used to automatically arrange and adapt parts of the models.

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Reinert, David; Humm, Bernhard (Betreuer); Rapp, Stefan (Betreuer); Jung, Florian (Betreuer)

Quantitative Analyse von Krebstumor-Bildmerkmalen aus CT-Aufnahmen des Kopf-Nacken-Bereichs

2017

Darmstadt, Hochschule, Bachelor Thesis, 2017

Korrekte Prognosen und Diagnosen im Bezug auf Krebserkrankungen stellen Ärzte auch heute noch vor eine große Herausforderung. Keine phänotypische Ausprägung eines Krebstumors gleicht einer anderen. Auch unterscheidet sich der Krankheitsverlauf bei jedem Patienten signifkant. Deshalb ist es notwendig die Behandlung für jeden Patienten zu individualisieren. Ziel dieser Arbeit war es, mit Hilfe von Radiomics zu untersuchen, ob Korrelationen zwischen Krebstumor-Bildmerkmalen und patientenspezifschen Informationen bestehen. Hierfür wurden Segmentierung und Feature-Extraktion durch eine implementierte Extraktions-Software für 38 CT-Bild-Datensätze des menschlichen Kopf-Nacken-Bereichs durchgeführt, um diese anschließend mit den zur Verfügung gestellten Meta-Daten des Patienten auf lineare Korrelation zu untersuchen. Wir konnten bei 17,54% der von uns extrahierten Radiomics eine starke Korrelation feststellen. 22,33% der Merkmale korrelierten mittelstark. Außerdem bestätigt die von uns verwendete Methodik bereits in der Medizin bekannte Korrelationen. Obwohl eine kleine Datenmenge untersucht wurde, sind die ersten Ergebnisse vielversprechend, müssen jedoch durch weitere Untersuchungen validiert werden.

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Rixels: Towards Secure Interactive 3D Graphics in Engineering Clouds

2017

Lukas, Uwe von (Ed.) et al.: Go-3D 2017: Mit 3D Richtung Maritim 4.0 : Tagungsband zur Konferenz Go-3D 2017. Stuttgart: Fraunhofer Verlag, 2017, pp. 25-43

Go-3D <8, 2017, Rostock, Germany>

Cloud computing rekindles old and imposes new challenges on remote visualization especially for interactive 3D graphics applications, e.g., in engineering and/or in entertainment. In this paper we present and discuss an approach entitled 'rich pixels' (short 'rixels') that balances the requirements concerning security and interactivity with the possibilities of hardware accelerated post-processing and rendering, both on the server side as well as on the client side using WebGL.

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Hafner, Morris; Kuijper, Arjan (Betreuer); Limper, Max (Betreuer)

Robust and Efficient Bijective Parameterization

2017

Darmstadt, TU, Bachelor Thesis, 2017

The goal of this thesis was to create a novel algorithm for bijective parameterizations of 3D triangle meshes with disk topology. Existing methods are either fast, but create non-bijective parameterizations, or are too slow to be applied to bigger meshes like high-resolution 3D scans or video game levels. We show an approach to transform an arbitrary, potentially non-bijective parameterization into a bijective mapping. The results show that the new algorithm produces results that are at least competitive with existing bijective parameterizers and still has room for future improvements.

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Wen, Zhuoman; Wang, Yanjie; Luo, Jun; Kuijper, Arjan; Di, Nan; Jin, Minghe

Robust, Fast and Accurate Vision-Based Localization of a Cooperative Target Used for Space Robotic Arm

2017

Acta Astronautica, Vol.136 (2017), pp. 101-114

When a space robotic arm deploys a payload, usually the pose between the cooperative target fixed on the payload and the hand-eye camera installed on the arm is calculated in real-time. A high-precision robust visual cooperative target localization method is proposed. Combing a circle, a line and dots as markers, a target that guarantees high detection rates is designed. Given an image, single-pixel-width smooth edges are drawn by a novel linking method. Circles are then quickly extracted using isophotes curvature. Around each circle, a square boundary in a pre-calculated proportion to the circle radius is set. In the boundary, the target is identified if certain numbers of lines exist. Based on the circle, the lines, and the target foreground and background intensities, markers are localized. Finally, the target pose is calculated by the Point-3-Perspective algorithm. The algorithm processes 8 frames per second with the target distance ranging from 0.3m to 1.5 m. It generated highprecision poses of above 97.5% on over 100,000 images regardless of camera background, target pose, illumination and motion blur. At 0.3 m, the rotation and translation errors were less than 0.015° and 0.2 mm. The proposed algorithm is very suitable for real-time visual measurement that requires high precision in aerospace.

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Mettel, Matthias Ruben; Alekseew, Michael; Stocklöw, Carsten; Braun, Andreas

Safety Services in Smart Environments Using Depth Cameras

2017

Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 80-93

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Falls of elderly persons are the most common cause of serious injuries in this age group. It is important to detect the fall in a timely manner. If medical help can't be provided immediately a deterioration of the patient's state may occur. In order to tackle this challenge, we want to propose two combined safety services that can utilize the same sensor to prevent and detect falls. The Dangerous Object Adviser detects small obstacles located on the floor and warns the user about the stumbling hazard when the user walks in their direction. The Fall Detection Service detects a fall and informs caregivers. This enables the caregivers to provide medical care in time. Both services are implemented by using the Microsoft Kinect, with the obstacles extracted from the depth image and the usage of skeleton tracking gives to provide the necessary information on the user position and pose.

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Bieber, Gerald; Seidel, Robert; Portwich, Rene

SARA - Subjective and Objective Data Acquisition for Physiotherapy Treatment Support

2017

Association for Computing Machinery (ACM): Proceedings of the 10th International Conference on PErvasive Technologies Related to Assistive Environments : PETRA 2017. New York: ACM, 2017. (ACM International Conference Proceedings Series (ICPS) 448), pp. 403-407

ACM International Conference on PErvasive Technologies Related to Assistive Environments (PETRA) <10, 2017, Island of Rhodes, Greece>

The work of physiotherapists is very important for the cure of patients. Physiotherapy has a long historical background. Physiotherapists are working almost manually, treat pain and movement restrictions, support rehabilitation and support the recovering of strength and wellbeing. The healing of the patients is a slow process and subjective impressions about pain or discomfort are important for the quality and adjustment of the treatment. The quality of treatment is dependent by the skills and knowledge of the therapist. Unfortunately, objective indicators of a good or successful treatment in the area of physiotherapy are rare; a comprehensive documentation after the therapy is often missing. With SARA, a platform for physiotherapy treatment support, the physiotherapist have received a new tool that allows an objective assessment of the treatment progress, the condition of their patients, and a documentation about the physical performance and further needs. This paper describes the concept and the measurement methods for the unobtrusive monitoring of the treatment quality and the results of the therapy.

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Search Intention Analysis for Task- and User-Centered Visualization in Big Data Applications

2017

Procedia Computer Science [online], Vol.104 (2017), pp. 539-547

International Conference on Tissue Engineering (ICTE) <2016, Riga, Latvia>

A new approach for classifying users' search intentions is described in this paper. The approach uses the parameters: word frequency, query length and entity matching for distinguishing the user's query into exploratory, targeted and analysis search. The approach focuses mainly on word frequency analysis, where different sources for word frequency data are considered such as the Wortschatz frequency service by the University of Leipzig and the Microsoft Ngram service (now part of the Microsoft Cognitive Services). The model is evaluated with the help of a survey tool and few machine learning techniques. The survey was conducted with more than one hundred users and on evaluating the model with the collected data, the results are satisfactory. In big data applications the search intention analysis can be used to identify the purpose of a performed search, to provide an optimal initially set of visualizations that respects the intended task of the user to work with the result data.

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Madapur Devraj, Sudeep Dev; Kraus, Dieter (Betreuer); Siegmund, Dirk (Betreuer)

Separation of Subjects in High-Security Locks by Using Capacitive Sensing

2017

Bremen, Hochschule, Master Thesis, 2017

A reliable distinction between one and more than one person in the automated access control is of great importance. When access to high-security area e.g. bank or in border control, here personal interlock is used. These systems ensure without human influence, that only a single individual can pass through a particular transit area (Mantrap Portal). Existing technical approaches use thermal imaging (Body Heat), RGB-D Images, Camera image based and computer vision algorithm to verify if there are one or more persons in the transit area. Other known systems use weight or photo sensor based methods for verification. In this Master's Thesis, we will investigate using capacitive sensors for this application. The most suitable capacitive sensing technique, as well as the number of sensors and their position, will be examined in this work. The performance of the developed system will be measured empirical testing and includes test scenarios in which an attacker tries to spoof the system. The system performance using capacitive sensors will be measured. Receiver operating characteristics (ROC) or Detection Error Tradeoff (DET) curves will show how the developed system performs compared with other solution. The work will conclude with a feasibility analysis of the capacitive sensor technique in a possible practical usage.

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Merz, Johannes; Kuijper, Arjan (Betreuer); Getto, Roman (Betreuer)

Simplified Definition of Parameter Spaces of a GML Model Using Sketch-based Interaction

2017

Darmstadt, TU, Master Thesis, 2017

This Master Thesis presents a novel technique to intuitively insert meta-parameters into a procedural GML model with the help of sketch-based interaction. A GML model consist of a sequence of procedural modeling commands, for example extrusions. These are called with a set of local offset values, which can be converted to global space and anchored in the surface mesh of the model. As the global positions do not necessarily lie on the mesh surface, this is done by finding reference vertices. The system uses a mesh deformation technique to deform the evaluated surface of the model and creates a progression of intermediate target meshes. During the deformation, the reference vertices provide the global offset positions, whose path can be approximated by a B-spline. By exchanging the initial values of the commands by this B-spline, a continuous parameter space of the meta-parameter is defined. The deformation process is supported by a mesh segmentation to create pre-defined deformation targets for the user. Using intuitive sketch-based methods, these can be easily adapted to the users needs. The results show that the system closely imitates the mesh deformation with the help of the modeling commands. Furthermore, the system was evaluated to be intuitive and easy to use.

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Single Image Marine Snow Removal based on a Supervised Median Filtering Scheme

2017

Imai, Francisco (Ed.) et al.: VISAPP 2017. Proceedings : 12th International Conference on Computer Vision Theory and Applications (VISIGRAPP 2017 Volume 4). SciTePress, 2017, pp. 280-287

International Conference on Computer Vision Theory and Applications (VISAPP) <12, 2017, Porto, Portugal>

Underwater image processing has attracted a lot of attention due to the special difficulties at capturing clean and high quality images in this medium. Blur, haze, low contrast and color cast are the main degradations. In an underwater image noise is mostly considered as an additive noise (e.g. sensor noise), although the visibility of underwater scenes is distorted by another source, termed marine snow. This signal disturbs image processing methods such as enhancement and segmentation. Therefore removing marine snow can improve image visibility while helping advanced image processing approaches such as background subtraction to yield better results. In this article, we propose a simple but effective filter to eliminate these particles from single underwater images. It consists of different steps which adapt the filter to fit the characteristics of marine snow the best. Our experimental results show the success of our algorithm at outperforming the existing approaches by effectively removing this phenomenon and preserving the edges as much as possible.

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Adams, Oliver; Bockholt, Ulrich; Hildebrand, Axel; Jonescheit, Leiv; Krzikalla, Roland; Olbrich, Manuel; Pankratz, Frieder; Pfützner, Sebastian; Roth, Matthias; Scheer, Fabian; Schwerdtfeger, Björn; Staack, Ingo; Wasenmüller, Oliver

Soll/Ist-Vergleich

2017

Schreiber, Werner (Ed.) et al.: Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie. Berlin: Springer Vieweg, 2017, pp. 263-307

Das Ziel des Anwendungsszenarios ist eine präzise Digitalisierung und die Erforschung effizienter Verfahren zur Integration dieser Umgebungsdaten in Mixed Reality Anwendungen. Einsatzgebiete für die Erfassung großer Messvolumina liegen im Bereich der Fabrik-, Produktions- und Montageplanung, bei denen ein realistisches digitales Abbild der vorhandenen Arbeitsumgebung eine wichtige zusätzliche Informationsquelle darstellt. Für kleine Messvolumina liegen die Einsatzbereiche in der Produktabsicherung entlang des gesamten Produktlebenszyklus. Das Anwendungsszenario "Soll/Ist-Vergleich" zeigt das Potential der Referenzarchitektur, weil hier zahlreiche existierende Technologien und ARVIDA-Entwicklungsergebnisse unterschiedlicher Partner über die Referenzarchitektur integriert wurden. Das Teilprojekt betrachtet zum einen die Umfelderkennung und Umfelderfassung in kleinen und großen Messvolumina, zum anderen wurden projektionsbasierte AR-Lösungen realisiert, durch die Verfahren für den Soll/Ist-Abgleich realisiert werden konnten.

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Siegmund, Dirk; Hörr, Oliver; Chiesa, Laura; Gabler, Frank; Braun, Andreas; Kuijper, Arjan

Talis - A Design Study for a Wearable Device to Assist People with Depression

2017

Reisman, Sorel (Ed.) et al.: 2017 IEEE 41st Annual Computer Software and Applications Conference Workshops : COMPSACW. Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2017, pp. 543-548

IEEE International COMPSAC Workshop on User Centered Design and Adaptive Systems (UCDAS) <4, 2017, Torino, Italy>

One of the major diseases affecting the global population, depression has a strong emotional impact on its sufferers. In this design study, "Talis" is presented as a wearable device which uses emotion recognition as an interface between patient and machine to support psychotherapeutic treatment. We combine two therapy methods, "Cognitive Behavioral Therapy" and "Well- Being Therapy", with interactive methods thought to increase their practical application potential. In this study, we draw on the results obtained in the area of "affective computing" for the use of emotions in empathic devices. The positive and negative phases experienced by the patient are identified through speech recognition and used for direct communication and later evaluation. After considering the design possibilities and suitable hardware, the future realization of such technology appears feasible. In order to design the wearable, user studies and technical experiments were carried out. The results of these suggest that the device could be beneficial for the treatment of patients with depression.

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Ternary Sparse Matrix Representation for Volumetric Mesh Subdivision and Processing on GPUs

2017

Computer Graphics Forum, Vol.36 (2017), 5, pp. 59-69

Eurographics Symposium on Geometry Processing (SGP) <15, 2017, London, UK>

In this paper, we present a novel volumetric mesh representation suited for parallel computing on modern GPU architectures. The data structure is based on a compact, ternary sparse matrix storage of boundary operators. Boundary operators correspond to the first-order top-down relations of k-faces to their (k-1)-face facets. The compact, ternary matrix storage format is based on compressed sparse row matrices with signed indices and allows for efficient parallel computation of indirect and bottomup relations. This representation is then used in the implementation of several parallel volumetric mesh algorithms including Laplacian smoothing and volumetric Catmull-Clark subdivision. We compare these algorithms with their counterparts based on OpenVolumeMesh and achieve speedups from 3x to 531x, for sufficiently large meshes, while reducing memory consumption by up to 36%.

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Ulmer, Alex; Kohlhammer, Jörn; Shulman, Haya

Towards Enhancing the Visual Analysis of Interdomain Routing

2017

Linsen, Lars (Ed.) et al.: IVAPP 2017. Proceedings : 8th International Conference on Information Visualization Theory and Applications (VISIGRAPP 2017 Volume 3). SciTePress, 2017, pp. 209-216

International Conference on Information Visualization Theory and Applications (IVAPP) <8, 2017, Porto, Portugal>

Interdomain routing with Border Gateway Protocol (BGP) plays a critical role in the Internet, determining paths that packets must traverse from a source to a destination. Due to its importance BGP also has a long history of prefix hijack attacks, whereby attackers cause the traffic to take incorrect routes, enabling traffic hijack, monitoring and modification by the attackers. Proposals for securing the protocol are adopted slowly or erroneous. Our goal is to create a novel visual analytics approach that facilitates easy and timely detection of misconfigurations and vulnerabilities both in BGP and in the secure proposals for BGP. This work initiates the analysis of the problem, the target users and state of the art approaches. We provide a comprehensive overview of the BGP threats and describe incidents that happened over the past years. The paper introduces two new user groups beside the network administrators, which should also be addressed in future approaches. It also contributes a survey about visual analysis of interdomain routing with BGP and secure proposals for BGP. The visualization approaches are rated and we derive seven key challenges that arise when following our roadmap for an enhanced visual analysis of interdomain routing.

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Damer, Naser; Rhaibani, Chadi Izzou; Braun, Andreas; Kuijper, Arjan

Trust the Biometric Mainstream: Multi-biometric Fusion and Score Coherence

2017

European Association for Speech, Signal and Image Processing (EURASIP): 2017 Proceedings of the 25th European Signal Processing Conference (EUSIPCO), pp. 2191-2195

European Signal Processing Conference (EUSIPCO) <25, 2017, Kos, Greece>

Multi-biometrics aims at building more accurate unified biometric decisions based on the information provided by multiple biometric sources. Information fusion is used to optimize the process of creating this unified decision. In previous works dealing with score-level multi-biometric fusion, the scores of different biometric sources belonging to the comparison of interest are used to create the fused score. This is usually achieved by assigning static weights for the different biometric sources with more advanced solutions considering supplementary dynamic information like sample quality and neighbours distance ratio. This work proposes embedding score coherence information in the fusion process. This is based on our assumption that a minority of biometric sources, which points out towards a different decision than the majority, might have faulty conclusions and should be given relatively smaller role in the final decision. The evaluation was performed on the BioSecure multimodal biometric database with different levels of simulated noise. The proposed solution incorporates, and was compared to, three baseline static weighting approaches. The enhanced performance induced by including the coherence information within a dynamic weighting scheme in comparison to the baseline solution was shown by the reduction of the equal error rate by 45% to 85% over the different test scenarios and proved to maintain high performance when dealing with noisy data.

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Bernard, Jürgen; Zeppelzauer, Matthias; Sedlmair, Michael; Aigner, Wolfgang

A Unified Process for Visual-Interactive Labeling

2017

Sedlmaier, Michael (Ed.) et al.: EuroVA 2017 : EuroVis Workshop on Visual Analytics. Goslar: Eurographics Association, 2017, pp. 73-77

International EuroVis Workshop on Visual Analytics (EuroVA) <8, 2017, Barcelona, Spain>

Assigning labels to data instances is a prerequisite for many machine learning tasks. Similarly, labeling is applied in visualinteractive analysis approaches. However, the strategies for creating labels often differ in the two fields. In this paper, we study the process of labeling data instances with the user in the loop, from both the machine learning and visual-interactive perspective. Based on a review of differences and commonalities, we propose the 'Visual-Interactive Labeling' (VIAL) process, conflating the strengths of both. We describe the six major steps of the process and highlight their related challenges.

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Unifying Algebraic Solvers for Scaled Euclidean Registration from Point, Line and Plane Constraints

2017

Lai, Shang-Hong (Ed.) et al.: Computer Vision - ACCV 2016. Part V : 13th Asian Conference on Computer Vision, Taipei, Taiwan, November 20-24, 2016, Revised Selected Papers. Springer International Publishing, 2017. (Lecture Notes in Computer Science (LNCS) 10115), pp. 52-66

Asian Conference on Computer Vision (ACCV) <13, 2016, Taipei, Taiwan>

We investigate recent state-of-the-art algorithms for absolute pose problems (PnP and GPnP) and analyse their applicability to a more general type, namely the scaled Euclidean registration from pointto- point, point-to-line and point-to plane correspondences. Similar to previous formulations we first compress the original set of equations to a least squares error function that only depends on the non-linear rotation parameters and a small symmetric coefficient matrix of fixed size. Then, in a second step the rotation is solved with algorithms which are derived using methods from algebraic geometry such as the Gröbner basis method. In previous approaches the first compression step was usually tailored to a specific correspondence types and problem instances. Here, we propose a unified formulation based on a representation with orthogonal complements which allows to combine different types of constraints elegantly in one single framework. We show that with our unified formulation existing polynomial solvers can be interchangeably applied to problem instances other than those they were originally proposed for. It becomes possible to compare them on various registrations problems with respect to accuracy, numerical stability, and computational speed. Our compression procedure not only preserves linear complexity, it is even faster than previous formulations. For the second step we also derive an own algebraic equation solver, which can additionally handle the registration from 3D point-to-point correspondences, where other solvers surprisingly fail.

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Unsupervised 3D Object Retrieval with Parameter-Free Hierarchical Clustering

2017

Mao, Xiaoyang (Ed.) et al.: CGI 2017. Proceedings of the Computer Graphics International Conference. New York: ACM, 2017. (ACM International Conference Proceedings Series (ICPS) 1368), 6 p.

Computer Graphics International (CGI) <34, 2017, Yokohama, Japan>

In 3D object retrieval, additional knowledge like user input, classification information or database dependent configured parameters are rarely available in real scenarios. For example, meta data about 3D objects is seldom if the objects are not within a well-known evaluation database. We propose an algorithm which improves the performance of unsupervised 3D object retrieval without using any additional knowledge. For the computation of the distances in our system any descriptor can be chosen; we use the Panorama-descriptor. Our algorithm uses a precomputed parameter-free agglomerative hierarchical clustering and combines the information of the hierarchy of clusters with the individual distances to improve a single object query. Additionally, we propose an adaption algorithm for the cases that new objects are added frequently to the database. We evaluate our approach with 6 databases including a total of 13271 objects in 481 classes. We show that our algorithm improves the average precision in an unsupervised scenario without any parameter configuration.

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Wendland, Steve; Lukas, Uwe von

Unterwassertestfeld für maritime Robotik und Sensorik

2017

Hydrographische Nachrichten, (2017), 106, pp. 40-42

In der Ostsee vor der Hanse- und Hafenstadt Rostock soll für die Entwicklung neuer Technologien ein multifunktionales Unterwassertestfeld entstehen, auf dem neue Produkte und Verfahren meerestechnischer Komponenten bzw. komplexe Geräte und Systeme erprobt, kalibriert und demonstriert werden können. Konkrete Unterwasserstrukturen aus dem Alltag der Offshore-Industrie, wie Seekabel, Pipelines, Gründungsstrukturen, sollen in dem Testfeld eingebracht werden, um ein reales, möbliertes Areal von Offshore-Anwendungen zu schaffen. Ergänzend dazu soll im Rostocker Fischereihafen ein Innovationscampus als Landbasis mit umfassender Infrastruktur aufgebaut werden. Der geplante Innovationscampus ermöglicht zukünftig mit der Kombination aus Unterwassertestfeld und modernstem Gebäudekomplex den gesamten Prozess der Entwicklung und Erprobungen an einem Standort: von der Produktidee über die Laborprüfung bis hin zur realen Anwendungserprobung auf See.

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Using Hand Gestures to Interact with an Industrial Robot in a Cooperative Flexible Manufacturing Scenario

2017

Proceedings of the 3rd International Conference on Mechatronics and Robotics Engineering : ICMRE 2017. New York: ACM, 2017. (ACM International Conference Proceedings Series (ICPS) 01414), pp. 11-16

International Conference on Mechatronics and Robotics (ICMRE) <3, 2017, Paris, France>

Gesture recognition is a booming field of interest for many researchers. The Human-Machine Interaction developed from using wired devices such as the mouse and the keyboard till using touch screens and nowadays is evolving to the gesture interaction. Simultaneously, the machine or the industrial robot in particular is developing as well. The usual trend of using an industrial robot in a typical factory is to isolate it from the workers during the operation, due to the safety regulations. However, nowadays a new generation of a safe cooperative industrial robot exists. These robots are no longer dangerous to work around the humans. In a flexible manufacturing system, a cooperative scenario between the worker and the industrial robot can achieve the flexible manufacturing objectives. Therefore, during this research we propose and implement a holonic control system architecture which connects the industrial robot with the worker together in the same work environment in a flexible cooperative scenario. Moreover, we use the worker hand gestures to generate control events associated with the worker activities. Accordingly, the interaction between the worker and the industrial robot can be established.

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Bär, Thomas; Bockholt, Ulrich; Hoffmann, Hilko; Jundt, Eduard; Roth, Matthias; Schreiber, Werner; Staack, Ingo; Zimmermann, Peter; Zürl, Konrad

Das Verbundprojekt ARVIDA

2017

Schreiber, Werner (Ed.) et al.: Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie. Berlin: Springer Vieweg, 2017, pp. 1-16

Ziel des BMBF-geförderten Verbundprojektes ARVIDA war die anwendungs- und nutzerorientierte Forschung, Entwicklung und Evaluation von zukunftsorientierten Technologien im Kontext der Virtuellen Techniken in Verbindung mit neuen und modernen Ansätzen des Semantic Web, mit dessen Hilfe Virtuelle Techniken über Dienste verbunden werden können, um zukünftig ein großes Maß an Interoperabilität unter Berücksichtigung von Echtzeitanforderungen sicherzustellen.

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Virtuelle Realität in der Medizin

2017

Kramme, Rüdiger (Ed.): Medizintechnik : Verfahren - Systeme - Informationsverarbeitung. Berlin, Heidelberg, New York: Springer, 2017, pp. 845-854

Die Virtuelle Realität (Virtual Reality, VR) - computergenerierte, dreidimensionale Welten - erlebt heutzutage eine noch nie dagewesene Popularität. Was in den 1980er- und 1990er-Jahren Forschungsinstitutionen und Universitäten vorbehalten war, ist mittlerweile im Massenmarkt angekommen. Dies ist mit Sicherheit auf die rapide Entwicklung und Verfügbarkeit kostengünstiger Virtual Reality Headsets zurück zu führen. Oculus Rift trat vor wenigen Jahren einen Siegeszug an, es folgten SAMSUNGs Gear VR oder HTCs Re Vive, um einige VR-Projekte zu nennen. Nun ist die Virtuelle Realität omnipräsent. Zugegebenermaßen wird in diesem Zusammenhang die Virtuelle Realität momentan hauptsächlich mit dem Game-Genre in Verbindung gebracht, jedoch ist es ein Frage der Zeit, bis auch andere Anwendungsfelder - so auch die Medizin - mit preiswerten VR-Lösungen und Headsets ernsthaft bearbeitet werden. Virtuelle Realität hat jedoch schon vor vielen Jahren Einzug in der Medizin erhalten. Rasante Entwicklungen der letzten Jahre in der Gerätetechnologie sowie bei den (Graphik-) Prozessorarchitekturen (GPU) haben zu einer zunehmend technologiebasierten Medizin geführt. Speziell auf dem Gebiet der Chirurgie wurden neue Möglichkeiten und ein Mehrwert gesehen.

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Visual Access to Performance Indicators in the Mining Sector

2017

Kozlíková, Barbora (Ed.) et al.: Eurographics / IEEE VGTC Conference on Visualization (EuroVis) - Short Papers. Goslar: Eurographics Association, 2017, pp. 157-161

Eurographics / IEEE VGTC Conference on Visualization (EuroVis) <19, 2017, Barcelona, Spain>

We introduce a visualization system that provides visual interactive access to information relevant for decision making in the mining sector. The mining sector is one of the most important industries in developing countries, especially in Africa. Stakeholders like governments, investors, and the civil society play an important role in the growth of the mining sector. They are interested in information reviewing individual country performances towards mining. The Mining Investment and Governance Review (MInGov) dataset explicitly addresses this issue. However, the complex data structure introduces challenges for the intuitive and easy understanding of the information. Together with mining sector experts, we conducted a design study with the goal to provide visual interactive access to investment- and policy-related information. We report on a domain characterization of the MInGov dataset, its potential users, and their tasks. Based on this analysis, we design a visualization system that supports mining-related decision making. Finally, we evaluate the visualization system in a user workshop with domain experts.

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Visual Interactive Creation and Validation of Text Clustering Workflows to Explore Document Collections

2017

Wischgoll, Thomas (Ed.) et al.: Visualization and Data Analysis 2017. Springfield: IS&T, 2017. (Electronic Imaging), pp. 46-57

Visualization and Data Analysis (VDA) <2017, Burlingame, CA, USA>

The exploration of text document collections is a complex and cumbersome task. Clustering techniques can help to group documents based on their content for the generation of overviews. However, the underlying clustering workflows comprising preprocessing, feature selection, clustering algorithm selection and parameterization offer several degrees of freedom. Since no "best" clustering workflow exists, users have to evaluate clustering results based on the data and analysis tasks at hand. In our approach, we present an interactive system for the creation and validation of text clustering workflows with the goal to explore document collections. The system allows users to control every step of the text clustering workflow. First, users are supported in the feature selection process via feature selection metrics-based feature ranking and linguistic filtering (e.g., part-of-speech filtering). Second, users can choose between different clustering methods and their parameterizations. Third, the clustering results can be explored based on the cluster content (documents and relevant feature terms), and cluster quality measures. Fourth, the results of different clusterings can be compared, and frequent document subsets in clusters can be identified. We validate the usefulness of the system with a usage scenario describing how users can explore document collections in a visual and interactive way.

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Brodkorb, Felix; Kopp, Manuel; Kuijper, Arjan; Landesberger, Tatiana von

Visual Interactive Creation of Geo-located Networks

2017

Linsen, Lars (Ed.) et al.: IVAPP 2017. Proceedings : 8th International Conference on Information Visualization Theory and Applications (VISIGRAPP 2017 Volume 3). SciTePress, 2017, pp. 283-293

International Conference on Information Visualization Theory and Applications (IVAPP) <8, 2017, Porto, Portugal>

Nodes in real world networks often have a geographic position. In many cases such as for simulation or optimization, there is a need for non-trivial synthetic geo-located networks. As synthetic datasets are required to have specific properties such as connectivity and geographic distribution, often networks need to be generated. However, their creation is cumbersome if done purely by hand, and inflexible if done fully automated. Here, we present a framework for creating artificial geographic located networks in a visually interactive way. We designed our framework with the what-you-see-is-what-you-get principle in mind, i.e. showing the (intermediate) results of the interactive creation process at any time and allowing the user to adjust the network iteratively. This design allows our system to be also used as a simple viewer for networks that have incomplete location information. Our approach consists of two steps: (1) Creating the network topology and (2) assigning locations to its nodes. Our half automatic system enables the user to easily set the location of the nodes to predefined areas like countries, states, and urban regions, while still being able to flexibly and interactively control the creation process. We show the utility of our system by creating a real-world-like geo-located network.

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Bernard, Jürgen; Dobermann, Eduard; Vögele, Anna; Krüger, Björn; Kohlhammer, Jörn; Fellner, Dieter W.

Visual-Interactive Semi-Supervised Labeling of Human Motion Capture Data

2017

Wischgoll, Thomas (Ed.) et al.: Visualization and Data Analysis 2017. Springfield: IS&T, 2017. (Electronic Imaging), pp. 34-45

Visualization and Data Analysis (VDA) <2017, Burlingame, CA, USA>

The characterization and abstraction of large multivariate time series data often poses challenges with respect to effectiveness or efficiency. Using the example of human motion capture data challenges exist in creating compact solutions that still reflect semantics and kinematics in a meaningful way. We present a visual-interactive approach for the semi-supervised labeling of human motion capture data. Users are enabled to assign labels to the data which can subsequently be used to represent the multivariate time series as sequences of motion classes. The approach combines multiple views supporting the user in the visual-interactive labeling process. Visual guidance concepts further ease the labeling process by propagating the results of supportive algorithmic models. The abstraction of motion capture data to sequences of event intervals allows overview and detail-on-demand visualizations even for large and heterogeneous data collections. The guided selection of candidate data for the extension and improvement of the labeling closes the feedback loop of the semi-supervised workflow. We demonstrate the effectiveness and the efficiency of the approach in two usage scenarios, taking visual-interactive learning and human motion synthesis as examples.

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Bernard, Jürgen; Ritter, Christian; Sessler, David; Zeppelzauer, Matthias; Kohlhammer, Jörn; Fellner, Dieter W.

Visual-Interactive Similarity Search for Complex Objects by Example of Soccer Player Analysis

2017

Linsen, Lars (Ed.) et al.: IVAPP 2017. Proceedings : 8th International Conference on Information Visualization Theory and Applications (VISIGRAPP 2017 Volume 3). SciTePress, 2017, pp. 75-87

International Conference on Information Visualization Theory and Applications (IVAPP) <8, 2017, Porto, Portugal>

The definition of similarity is a key prerequisite when analyzing complex data types in data mining, information retrieval, or machine learning. However, the meaningful definition is often hampered by the complexity of data objects and particularly by different notions of subjective similarity latent in targeted user groups. Taking the example of soccer players, we present a visual-interactive system that learns users' mental models of similarity. In a visual-interactive interface, users are able to label pairs of soccer players with respect to their subjective notion of similarity. Our proposed similarity model automatically learns the respective concept of similarity using an active learning strategy. A visual-interactive retrieval technique is provided to validate the model and to execute downstream retrieval tasks for soccer player analysis. The applicability of the approach is demonstrated in different evaluation strategies, including usage scenarions and cross-validation tests.

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Visualisierung einer komplexen Offshore-Konverterplattform in interaktiven Frameraten

2017

Lukas, Uwe von (Ed.) et al.: Go-3D 2017: Mit 3D Richtung Maritim 4.0 : Tagungsband zur Konferenz Go-3D 2017. Stuttgart: Fraunhofer Verlag, 2017, pp. 123-133

Go-3D <8, 2017, Rostock, Germany>

Die Visualisierung von 3D-CAD Daten in der maritimen Industrie ist sinnvoll, um die Prozesse in den späten Phasen des Produktlebenszyklus, wie z. B. Training oder Nachrüstung, zu unterstützen. Eine wesentliche Herausforderung ist die Visualisierung sehr großer Datensätze in interaktiven Frameraten. In diesem Artikel werden laufende Arbeiten des Fraunhofer IGD im Rahmen des Projekts OWS - Offshore Wind Solutions1 vorgestellt, welche das Ziel haben, eine komplexe Offshore-Konverterplattform so zu visualisieren, dass interaktive Schulungen am virtuellen Produkt realisiert werden können. Es wird gezeigt, wie dieses Ziel durch effektive Reduktion der Renderinglast mittels Culling, Level of Detail und Renderingbudgetierung über die Zeit erreicht werden kann.

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Reynolds, Steven Lamarr; Kuijper, Arjan (Betreuer); May, Thorsten (Betreuer)

Visualisierung von zeitlichen, thematischen Änderungen in einem Dokumentenkorpus

2017

Darmstadt, TU, Bachelor Thesis, 2017

Mehrere Dokumente in einem Korpus können mit Themen beschrieben werden. Diese Themen bestehen aus Termen die sich aus den Wörtern der Dokumente bilden. Das Thema der vorliegenden Bachelorarbeit beschäftigt sich mit der Visualisierung der Entwicklung dieser Themen über einen Zeitstrahl. Über mehrere Zeitabschnitte hinweg werden Themen aus Dokumenten generiert. In einer Visualisierung wird die Entwicklung der Themen über diese Zeitabschnitte dargestellt. Dazu wird die Ähnlichkeit zwischen Themen berrechnet und angezeigt. Die Themen werden sortiert um die Visualisierung möglichst visuell und ansprechend darzustellen. Damit können Entwicklungen der Themen betrachtet werden. Das System erlaubt ein späteres austauschen des verwendeten Topic Modeling Verfahrens und ein schnellen Import von Dokumentenkorpera. Die Visualisierung ist unabhängig von dem Topic Modeling Verfahren. Zusätzlich wird mittels Interaktionstechniken eine Visual Analytics Anwendung umgesetzt.

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Bockholt, Ulrich; Brauns, Sarah; Fluck, Oliver; Harth, Andreas; Keitler, Peter; Koriath, Dirk; Lengowski, Stefan; Olbrich, Manuel; Staack, Ingo; Rautenberg, Ulrich; Widor, Volker

Werkerassistenz

2017

Schreiber, Werner (Ed.) et al.: Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie. Berlin: Springer Vieweg, 2017, pp. 309-377

Es werden Szenarien beschrieben, die sich mit Aufgabenstellungen der Mitarbeiterführung und der Mitarbeiter-Assistenz in der Industrie befassen. Im Anwendungsszenario "MR-Engineering" wurden Systemlösungen erforscht, mit denen Planer, Arbeitsvorbereiter und In-Betrieb-Nehmer mit Hilfe von virtuellen Techniken und individuellen Software- Lösungen in Zukunft unterstützt werden können. Im Szenario "3D-Bauplanung" wird die automatische Verknüpfung von Generalplan und Daten zur Auftragsabwicklung dargestellt. Ziel ist es, die Arbeit des Planers mit effizienteren und anschaulicheren Folgen von Arbeitsschritten zu vereinfachen. In den weiteren Szenarien "3D-Bauanleitung", "Intelligentes Schema" und "Fertigen ohne Zeichnung" wird die Planung von Rohrleitungen und die Ableitung von Bauanleitungen unterstützt. Hier werden Daten zusammengeführt und über Augmented Reality visualisiert. Im Unterkapitel "Mobile Projektionsbasierte Assistenzsysteme" werden in vier Anwendungsszenarien Systeme entwickelt und beschrieben, die den Mitarbeiter bei der Bewältigung verschiedener Arbeitsaufgaben durch Augmented Reality mobil unterstützen. Diese AR Komponenten sind im Wesentlichen Projektionssysteme, die durch optisches Tracking mobilisiert werden. Der Schwerpunkt liegt hier in der Integration von Tracking-Systemen und Datendiensten durch die ARVIDA-Referenzarchitektur. Der Forschungsschwerpunkt im Anwendungsszenario "Instandhaltung und Training" war das schnelle und einfache Trainieren von komplexen wiederkehrenden Arbeitsabläufen. Durch vielfältige und variantenreiche Produkte ist die klassische Erstellung von Trainingsszenarien nicht mehr zu bewältigen. In drei aufeinander aufbauenden Phasen entstand in diesem Teilprojekt eine Trainingsapplikation, mit der es einem Trainer möglich ist, eigenständig und schnell Trainingsmodule ohne Programmier- oder VR-Kenntnisse zu erstellen. Im Training werden dem Trainee die Informationen als sowohl statische wie auch kongruente Überlagerungen mittels Datenbrille direkt im Sichtfeld angezeigt.

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Designstudie und Entwicklung von Konzepten zur visuellen Trendanalyse für mobile Umgebungen

2017

Darmstadt, TU, Master Thesis, 2017

Die immer schneller wachsenden Datenmengen in nahezu allen Bereichen des Lebens führen zu dem verstärkten Bestreben, die darin enthaltenen Informationen zu gewinnen und nützlich einzusetzen. Die menschlichen Kapazitäten im Hinblick auf die kognitive Verarbeitung von Informationen sind jedoch begrenzt. Daher werden Techniken und Methoden entwickelt, um den Menschen bei dieser Aufgabe zu unterstützen. Eine Ausprägung der Informationssuche in Datenmengen ist die analytische Untersuchung der Daten. Dazu gehört unter anderem das Erkennen von Trends und Mustern. Visual Analytics hat das Ziel, den Menschen durch eine Kombination aus Informationsvisualisierungen und automatisierten Analyseverfahren bei diesem Prozess zu unterstützen. Die meiste Forschung auf diesem Gebiet bezieht sich bislang überwiegend auf Computer und Laptops. Durch die rasante Verbreitung von mobilen Geräten in den letzten Jahren entstand die Notwendigkeit, die Methoden und Techniken auch im Hinblick auf den Einsatz auf mobilen Geräten zu untersuchen. Die mobile Umgebung bringt neue Herausforderungen, aber auch Möglichkeiten, mit sich. Am Fraunhofer IGD in Darmstadt wurde eine Software zur visuellen Trendanalyse auf Basis von digitalen Publikationsdatenbanken entwickelt. Ziel ist es, durch die Visualisierung der darin zur Verfügung stehenden Informationen, aufkommende und verschwindende Trends zu erkennen. Diese Software ist allerdings für die Benutzung auf einem Desktop-Computer ausgelegt. Im Rahmen dieser Arbeit wurde daher eine Designstudie durchgeführt, um die Designmöglichkeiten zur Umsetzung der Software auf mobilen Geräten zu untersuchen. Dazu wurde ein Modell der Zielgruppe (Entscheidungsträger) erstellt, welches aus drei Eigenschaften besteht. Eine dieser Eigenschaften besteht aus zwei Merkmalen - Bauchgefühl und Verstand - welche als gegensätzliche Aspekte identifiziert wurden, deren Vorteile jedoch jeweils stark vom Kontext abhängen. Gerade bei mobilen Umgebungen hat der sich stets verändernde Kontext einen starken Einfluss auf die Benutzererfahrung. Adaptive Mechanismen mit Bezug auf die mentale Verfassung des Benutzers (z.B. geteilte Aufmerksamkeit) können große Vorteile im Hinblick auf die positive Nutzererfahrung mit sich bringen. Im Rahmen dieser Designstudie wurden drei Designs entwickelt und untersucht, die jeweils das Bauchgefühl, den Verstand oder eine Kombination aus beiden in den Fokus stellen. Die Konzepte wurden prototypisch implementiert und im Rahmen eines kleinen kontrollierten Experiments evaluiert.

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Reinhard, Johann; Kuijper, Arjan (Betreuer); Brunton, Alan (Betreuer)

Discrete Medial Axis Transform and Applications for 3D Printing

2017

Darmstadt, TU, Bachelor Thesis, 2017

3D printing is becoming a more commonly used manufacturing process, both for industrial and consumer use, with ever increasing capabilities and areas of application. These opportunities also introduce higher expectations on the quality of the resulting prints, generally in terms of the resulting shape and appearance of the object, but also rigidness and structural integrity. Detecting characteristics in a model that are a source of errors opens up possible approaches to mitigate or eliminate these errors before printing it. One such characteristic are thin structures that can lead to missing or deformed shapes, changes in the appearance of full color prints or fragile structures that break during post-processing steps. The aim of this work is to detect thin structures using the discrete medial axis, representing the centers of a shape. In order to compute the discrete medial axis a discrete medial axis transform based on image processing techniques is implemented in the Cuttlefish 3D printer driver. The result for different models are assessed and possible correlations of the medial axis and thin structures evaluated. Possible applications of the medial axis or filtered medial axis are proposed and discussed.