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3D Mass Digitization: A Milestone for Archeological Documentation

2017

VAR. Virtual Archaeology Review [online]

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

CGI 2017. Proceedings of the Computer Graphics International Conference

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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Schinko, Christoph; Krispel, Ulrich; Eggeling, Eva; Ullrich, Torsten

3D Model Representations and Transformations in the Context of Computer-Aided Design: A State-of-the-Art Overview

2017

MMEDIA 2017

International Conferences on Advances in Multimedia (MMEDIA) <9, 2017, Venice, Italy>

Within a virtual world, either in virtual reality or in a simulation environment, the digital counterparts of real objects are described by mathematical and computational models. Depending on the purpose, the field of application, and the used toolchain a wide variety of model representations is established. As a consequence, conversion methods and transformation algorithms are becoming increasingly important. This article gives a state of the art overview on model representations and on the most important transformation techniques.

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Jarke, Matthias; Fellner, Dieter W.; Fuhrmann, Constanze; Toubekis, Georgios; Santos, Pedro

3D-Digitalisiertechnologien im Anwendungsfeld Kulturerbe – Stand, Stellenwert und Perspektiven

2017

Ausgewählte Experten aus Wissenschaft, Kultur und Industrie erarbeiteten den jeweilige Handlungs- und Forschungsbedarf und formulierte konkrete Empfehlungen. Arbeitsgruppen zu den Herausforderungen Forschung und Entwicklung (3D-Druck, Web3D-Visualisierung, Akquiseverfahren, semantische Annotation, Datenerhaltung), Gesellschaft/ Politik (Langzeitarchivierung, Standards, digitale Rechte, Strategie) und Markt (Marketing, Business-Modelle, industrielle Anwendungsfelder) boten hierfür den erforderlichen Rahmen, die vielseitigen Themenbereiche der Prozesskette der 3D-Digitalisierung abzudecken und Anwendungsmöglichkeiten, Vorteile und Nutzen von 3D-Technologien zu erörtern.

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Majewski, Martin; Kuijper, Arjan [1. Gutachten]; Braun, Andreas [2. Gutachten]

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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Cheng, Wentao; Lin, Weisi; Zhang, Xinfeng; Goesele, Michael; Sun, Ming-Ting

A Data-Driven Point Cloud Simplification Framework for City-Scale Image-Based Localization

2017

IEEE Transactions on Image Processing

City-scale 3D point clouds reconstructed via structure-from-motion from a large collection of Internet images are widely used in the image-based localization task to estimate a 6-DOF camera pose of a query image. Due to prohibitive memory footprint of city-scale point clouds, image-based localization is difficult to be implemented on devices with limited memory resources. Point cloud simplification aims to select a subset of points to achieve a comparable localization performance using the original point cloud. In this paper, we propose a data-driven point cloud simplification framework by taking it as a weighted K-Cover problem, which mainly includes two complementary parts. First, a utility-based parameter determination method is proposed to select a reasonable parameter K for K-Cover-based approaches by evaluating the potential of a point cloud for establishing sufficient 2D-3D feature correspondences. Second, we formulate the 3D point cloud simplification problem as a weighted K-Cover problem, and propose an adaptive exponential weight function based on the visibility probability of 3D points. The experimental results on three popular datasets demonstrate that the proposed point cloud simplification framework outperforms the state-of-the-art methods for the image-based localization application with a well predicted parameter in the K-Cover problem.

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Bidarahalli, Suman; Kuijper, Arjan [1. Gutachten]; Brunton, Alan [2. Gutachten]

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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Hussain, Masood; Kuijper, Arjan [1. Gutachten]; Burkhardt, Dirk [2. Gutachten]

A Distributed Approach for Web-Evaluations of Desktop and Web-Based Applications

2017

Darmstadt, TU, Master Thesis, 2017

The process of evaluation is an important concept, and it has a wide range of advantages. The purpose of evaluation can vary from project to project and usually it is used to check system usability, acceptability, and functionality. Evaluation can also be used to compare two existing systems, or to analyse the benefits of the new approach against the existing approaches. Today, there are many existing methods which can be used to perform evaluation. Among the existing methods, the most effective is the distance evaluation method because of being cost-effective. It is easy to manage the distance evaluation and to analyze the result because it follows the already defined procedure. However, the distance evaluation method can only be used to evaluate web applications and is not applicable to desktop applications. In this thesis, an approach is suggested that will enable the user to perform distance evaluation of the desktop applications. The approach extends the existing Web-based Evaluation of Information Visualization which is currently limited to web applications. The idea is to transfer the desktop application from the host application computer and display it in the web browser without compromising the security of the host computer. For the security purpose, the interaction of the participant is only limited to the application, and the participant cannot use any other feature of the remote host. The suggested approach successfully evaluate the desktop applications.

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

A Unified Process for Visual-Interactive Labeling

2017

EuroVA 2017

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

2017

Mixed Reality and Gamification for Cultural Heritage

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

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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Achieving Fluid Detection by Exploiting Shadow Detection Methods

2017

Imaging for Patient-Customized Simulations and Systems for Point-of-Care Ultrasound

International Workshop on Point-of-Care Ultrasound (POCUS) <2017, Québec City, QC, Canada>

Ultrasound provides a useful and readily available imaging tool. The big challenge in acquiring a good ultrasound image are possible shadow artefacts that hide anatomical structures. This applies in particular to 3D ultrasound acquisitions, because shadow artefacts may be recorded outside the visualized image plane. There are only a few automatic methods for shadow artefact detection. In our work we like to introduce a new shadow detection method that is based on an adaptive thresholding approach. The development was attempted, after existing methods had been extended to separate shadow and fluid regions. The entire detection procedure utilizes only the ultrasound scan line information and some basic knowledge about the ultrasound propagation inside the human body. Applying our method, the ultrasound operator can retrieve combined information about shadow and fluid locations, that may be invaluable for image acquisition or diagnosis. The method can be applied to conventional 2D as well as 3D ultrasound images.

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Gangatharan, Dinesh Vaithyalingam; Kupnik, Mario [Supervisor 1]; Fu, Biying [Supervisor 2]

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 [Ed.]; Wichert, Reiner [Ed.]; Maña, Antonio [Ed.]

Ambient Intelligence

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

  • 978-3-319-56996-3
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An Exploratory Study on Electric Field Sensing

2017

Ambient Intelligence

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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Le Moan, Steven; Tanksale, Tejas Madan; Byshko, Roman; Urban, Philipp

An Observer-Metamerism Sensitivity Index for Electronic Displays

2017

Journal of the Society for Information Display

The effect of observer metamerism induced by electronic displays depends to a large extent on their primary spectra (red, green, and blue in the most common case). In particular, for narrow-band primary spectra whose peak wavelength lies in the range of high variability of the observer's colormatching function, some observers can experience very large differences between actual surface colors (e.g. in a light booth) and displayed colors if the monitor is optimized for the International Commission on Illumination (CIE) 1931 standard observer. However, because narrow-band light-emitting diodes lead to larger color gamuts, more and more monitors with very narrow band primaries are coming onto the market without manufacturers taking into account the associated problem of observer variations. Being able to measure these variations accurately and efficiently is therefore an important objective. In this paper, we propose a new approach to predict the extent of observer metamerism for a particular multiprimary display. Unlike existing dedicated models, ours does not depend on a reference illuminant and a set of reflectance spectra and is computationally more efficient.

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An Ontology-Based Approach to Enable Knowledge Representation and Reasoning in Worker-Cobot Agile Manufacturing

2017

Future Internet

There is no doubt that the rapid development in robotics technology has dramatically changed the interaction model between the Industrial Robot (IR) and the worker. As the current robotic technology has afforded very reliable means to guarantee the physical safety of the worker during a close proximity interaction with the IR. Therefore, new forms of cooperation between the robot and the worker can now be achieved. Collaborative/Cooperative robotics is the new branch of industrial robotics which empowers the idea of cooperative manufacturing. Cooperative manufacturing significantly depends on the existence of a collaborative/cooperative robot (cobot). A cobot is usually a Light-Weight Robot (LWR) which is capable of operating safely with the human co-worker in a shared work environment. This is in contrast with the conventional IR which can only operate in isolation from the worker workspace, due to the fact that the conventional IR can manipulate very heavy objects, which makes it so dangerous to operate in direct contact with the worker. There is a slight difference between the definition of collaboration and cooperation in robotics. In cooperative robotics, both the worker and the robot are performing tasks over the same product in the same shared workspace but not simultaneously. Collaborative robotics has a similar definition, except that the worker and the robot are performing a simultaneous task. Gathering the worker and the cobot in the same manufacturing workcell can provide an easy and cheap method to flexibly customize the production. Moreover, to adapt with the production demands in the real time of production, without the need to stop or to modify the production operations. There are many challenges and problems that can be addressed in the cooperative manufacturing field. However, one of the most important challenges in this field is the representation of the cooperative manufacturing environment and components. Thus, in order to accomplish the cooperative manufacturing concept, a proper approach is required to describe the shared environment between the worker and the cobot. The cooperative manufacturing shared environment includes the cobot, the co-worker, and other production components such as the product itself. Furthermore, the whole cooperative manufacturing system components need to communicate and share their knowledge, to reason and process the shared information, which eventually gives the control solution the capability of obtaining collective manufacturing decisions. Putting into consideration that the control solution should also provide a natural language which is human readable and in the same time can be understood by the machine (i.e., the cobot). Accordingly, a distributed control solution which combines an ontology-based Multi-Agent System (MAS) and a Business Rule Management System (BRMS) is proposed, in order to solve the mentioned challenges in the cooperative manufacturing, which are: manufacturing knowledge representation, sharing, and reasoning.

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Analyzing the Information Search Behavior and Intentions in Visual Information Systems

2017

Journal of Computer Science Technology Updates

Visual information search systems support different search approaches such as targeted, exploratory or analytical search. Those visual systems deal with the challenge of composing optimal initial result visualization sets that face the search intention and respond to the search behavior of users. The diversity of these kinds of search tasks require different sets of visual layouts and functionalities, e.g. to filter, thrill-down or even analyze concrete data properties. This paper describes a new approach to calculate the probability towards the three mentioned search intentions, derived from users' behavior. The implementation is realized as a web-service, which is included in a visual environment that is designed to enable various search strategies based on heterogeneous data sources. In fact, based on an entered search query our developed search intention analysis web-service calculates the most probable search task, and our visualization system initially shows the optimal result set of visualizations to solve the task. The main contribution of this paper is a probability-based approach to derive the users' search intentions based on the search behavior enhanced by the application to a visual system.

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Applying the PROSA Reference Architecture to Enable the Interaction between the Worker and the Industrial Robot

2017

ICAART 2017 Vol. 1

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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Bernard, Jürgen; Vögele, Anna; Klein, Reinhard; Fellner, Dieter W.

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

2017

IVAPP 2017. Proceedings

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

2017

Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie

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

Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie

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

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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Hohenberg, Christopher Rudi; Latzel, Thomas [Betreuer]; Vahl, Matthias [Betreuer]; Hilgenfeld, Carsten [Betreuer]

Augmentation von Webcam-Bildern mit AIS-Daten

2017

München, Univ. der Bundeswehr, Master Thesis, 2017

In this master's thesis a prototype was developed, which is able to show data from the Automatic Identification System (AIS) in an Augmented Reality (AR). Therefor Webcam-Images of a maritime scene where fused with AIS-Data, so that the user could see the information of the ship immediately in the image. Goal of this work was to exactly mark the ships with an AIS-Signal in the Webcam-Image. Even when the camera was moved the software should work fine. The type of the camera shouldn't influence the functionality of the software. A fluent transfer via the internet will be guaranteed. The ships without an AIS-Signal shouldn't be labeled. Disturbing and irrelevant objects where ignored. Only ships in the image space where labeled. Label shouldn't interleave each other. With increasing distance of the objects to the camera the label will get paler. The speed of the ship will influence the color of the label. In the label the name of the ship will be printed. The label will be placed in the image where the ship is. In this thesis the minimum requirements of the webcam where mentioned. The necessary configuration parameters where described in this thesis. Initially four concepts where presented and evaluated. During the project the concepts "location determination via transformation" and "ship detection with machine vision" were implemented. For the realization, the manipulation and the processing of image data is essentially. After an image preprocessing (rectifying of images) a transformation of ship positions from the WGS84-Format into pixel was implemented. The mathematical coherence and the usage of the open-source-bibliophile, OpenCV and cURL, were described in this thesis. After a preliminary result evaluation timing differences between image and AIS-Data were evaluated as the source of error. Through object detection this error was minimized. The given requirements could largely be complied. A detailed evaluation is part of this thesis.

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Frank, Sebastian; Kuijper, Arjan

AuthentiCap - A Touchless Vehicle Authentication and Personalization System

2017

Ambient Intelligence

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 [1. Gutachten]; Getto, Roman [2. Gutachten]

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

Computer Assisted and Robotic Endoscopy and Clinical Image-Based Procedures

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 [Prüfer]; Oyarzun Laura, Cristina [Betreuerin]

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 [Gutachter]; Aehnelt, Mario [Gutachter]

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 [1. Gutachten]; Fu, Biying [2. Gutachten]

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

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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Brömme, Arslan [Ed.]; Busch, Christoph [Ed.]; Dantcheva, Antitza [Ed.]; Rathgeb, Christian [Ed.]; Uhl, Andreas [Ed.]

BIOSIG 2017

2017

Annual International Conference of the Biometrics Special Interest Group (BIOSIG) <16, 2017, Darmstadt, Germany>

GI-Edition - Lecture Notes in Informatics (LNI)
P-270

Biometrics provides efficient and reliable solutions to recognize individuals. With increasing number of identity theft and misuse incidents we do observe a significant fraud in e-commerce and thus growing interests on trustworthiness of person authentication. Nowadays we find biometric applications in areas like border control, national ID cards, e-banking, e-commerce, e-health etc. Large-scale applications such as the European Union Smart-Border Concept, the Visa Information System (VIS) and Unique Identification (UID) in India require high accuracy and also reliability, interoperability, scalability and usability. Many of these are joint requirements also for forensic applications. Multimodal biometrics combined with fusion techniques can improve recognition performance. Efficient searching or indexing methods can accelerate identification efficiency. Additionally, quality of captured biometric samples can strongly influence the performance. Moreover, mobile biometrics is an emerging area and biometrics based smartphones can support deployment and acceptance of biometric systems. However, concerns about security and privacy cannot be neglected. The relevant techniques in the area of presentation attack detection (liveness detection) and template protection are about to supplement biometric systems, in order to improve fake resistance, prevent potential attacks such as cross matching, identity theft etc. BIOSIG 2017 addresses these issues and will present innovations and best practices that can be transferred into future applications. Once again a platform for international experts' discussions on biometrics research and the full range of security applications is offered to you.

  • 978-3-88579-664-0
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Hellhake, Tim; Letschert, Thomas [Supervisor]; Krämer, Michel [Advisor]

Building a Scalable and Fault-tolerant Cloud Architecture for the Distributed Execution of Workfows

2017

Gießen, TH Mittelhessen, Master Thesis, 2017

Due to the massive amount of data that accumulates during the collection of geospatial data, it is not possible to process the data on a single system. To solve this problem, numerous frameworks for distributing the workload to multiple computing nodes have been developed in the past years. However, most of the frameworks provide their own paradigm or even language to solve problems. Therefore it's often necessary to reimplement the algorithms of existing libraries. Furthermore, the use of a particular framework often leads to a vendor lock-in. Moreover, most of the tools, are designed to be executed on a static grid leaving the opportunities of modern cloud environments unused. This thesis proposes a highly scalable and fault tolerant solution to distribute work throughout a dynamically growing cluster of computing nodes. Unlike other solution, it does not force the user into a particular framework. It's a modular architecture which allows the integration of already existing frameworks to enable the execution of workows.

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

2017

ECMS 2017

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

MobileHCI 2017

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

VISAPP 2017. Proceedings

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

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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Combining Adaptive Holonic Control and ISA-95 Architectures to Self-Organize the Interaction in a Worker-Industrial Robot Cooperative Workcell

2017

Future Internet

Self-Organization is a spontaneous trend which exists in nature among different organisms. Self-organization refers to the process where some form of an overall order arises in a group due to the local interaction among the members of this group. In manufacturing, a similar definition of a Reconfigurable Manufacturing System (RMS) can be found. RMS is a system where the production components and functions can be modified, rearranged and/or interchanged in a timely and cost-effective manner to quickly respond to the production requirements. The definition of the RMS concept implies that the self-organization is an important key factor to fulfil that concept. A case study where a cooperation among a variable number of Industrial Robots (IRs) and workers is studied to show the importance of the research problem. The goal of the paper is to offer a suitable generic control and interaction architecture solution model, which obtains the self-organization from the RMS point of view. Ultimately, applying the proposed solution concept to the case study.

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

Combining Cluster and Outlier Analysis with Visual Analytics

2017

EuroVA 2017

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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Alm, Rebekka

Contextualization and Recommendation of Annotations to Enhance Information Exchange in Assembly Assistance

2017

J.UCS Journal of Universal Computer Science

Increasingly flexible production processes require intelligent assistance systems containing information and knowledge to maintain high quality and efficiency. To ensure a reliable supply of information, it is of great importance to find easy and fast ways to record and store "new" information, as well as to provide a sensible mechanism to supply the information when needed. In this paper an approach is presented that uses annotations in combination with a formalized knowledge base that represents the work domain. This pre-condition enables a context-based annotation recommendation. A framework is proposed to integrate different factors to measure the relevance of an annotation according to a given situation. The approach is illustrated using the example of an assembly assistance system. To evaluate the users' attitude regarding annotations as instruction support and to test the system's capabilities when handling a great number of annotations some studies were performed and analyzed.

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

2017

GRAPP 2017. Proceedings

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]

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

Das Verbundprojekt ARVIDA

2017

Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie

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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Krispel, Ulrich; Evers, Henrik Leander; Tamke, Martin; Ullrich, Torsten

Data Completion in Building Information Management: Electrical Lines from Range Scans and Photographs

2017

Visualization in Engineering

Background: The concept of building information management (BIM) is based on its holistic nature. This idea pays off, if all relevant information is fused into one consistent data set. As a consequence, the completeness of data is vital and the research question on how to complete data automatically remains open. Methods: In this article we present a data completion technique based on knowledge management. We encode expert and domain knowledge in a generative system that represents norms and standards in a machine-readable manner. The implementation of this approach be used to automatically determine a hypothesis on the location of electrical lines within indoor range scans. Results: The generative paradigm can encode domain expert knowledge in a machine-readable way. In this article we demonstrate its usage to represent norms and standards. Conclusions: The benefit of our method is the further completion of digital building information models -- a necessary step to take full advantage of building information modeling.

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Knuth, Martin; Bender, Jan; Goesele, Michael; Kuijper, Arjan

Deferred Warping

2017

IEEE Computer Graphics and Applications

We introduce deferred warping, a novel approach for real-time deformation of 3D objects attached to an animated or manipulated surface. Our target application is virtual prototyping of garments where 2D pattern modeling is combined with 3D garment simulation which allows an immediate validation of the design. The technique works in two steps: First, the surface deformation of the target object is determined and the resulting transformation field is stored as a matrix texture. Then the matrix texture is used as look-up table to transform a given geometry onto a deformed surface. Splitting the process in two steps yields a large flexibility since different attachment types can be realized by simply defining specific mapping functions. Our technique can directly handle complex topology changes within the surface. We demonstrate a fast implementation in the vertex shading stage allowing the use of highly decorated surfaces with millions of triangles in real-time.

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Abid, Elyes; Hergenröther, Elke [Referentin]; Weber, Hans-Peter [Korreferent]; Henniger, Olaf [Betreuer]

Demonstrator eines Bezahlterminals für Bankkarten mit Unterschrifts-On-Card-Vergleich auf Android

2017

Darmstadt, Hochschule, Bachelor Thesis, 2017

Smartcard bedeutet im täglichen Leben eine große Erleichterung. Die Zahlung mit einer einfachen Unterschrift ist bequem und schnell. Um den Vorgang zu bestätigen, wurde bisher aber nur oberflächlich die vorgelegte Unterschrift mit der Unterschrift der auf Karte verglichen. PINs können gestohlen, weitergegeben oder vergessen werden. Um solche Nachteile zu vermeiden, sollen biometrische Merkmale mit Smartcards verbunden werden. Die dabei genutzten Online-Unterschriften sind im Vergleich verschiedener Methoden zur Freigabe von Smartcards die sichersten. Ziel dieser Arbeit ist die Entwicklung eines biometrischen Verfahrens zur Benutzerauthentifizierung auf einer Smartcard mit Hilfe eines Android Tablets. Als biometrischen Daten werden On-line-Unterschriften genutzt, d. h. handgeschriebene Unterschriften, die mit Tablet aufgenommen werden können.

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Vetter, Sven; Basgier, Dennis [Gutachter]; Thöner, Maik [Gutachter]

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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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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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

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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Reinhard, Johann; Kuijper, Arjan [1. Gutachten]; Brunton, Alan [2. Gutachten]

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.

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E-Textile Couch: Towards Smart Garments Integrated Furniture

2017

Ambient Intelligence

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 Arthur; Urban, Bodo

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

2017

CHI '17. Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems

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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Liu, Yisi; Trapsilawati, Fitri; Hou, Xiyuan; Sourina, Olga; Chen, Chun-Hsien; Kiranraj, Pushparaj; Müller-Wittig, Wolfgang K.; Ang, Wei Tech

EEG-based Mental Workload Recognition in Human Factors Evaluation of Future Air Traffic Control Systems

2017

Transdisciplinary Engineering: A Paradigm Shift

ISPE International Conference on Transdisciplinary Engineering <24, 2017, Singapore>

With growing air traffic density, air-traffic controllers (ATCOs) are facing more challenges in interpreting and analyzing air traffic information. As one of the solutions to this problem, automation supports such as tactile human computer interface, interactive 3D radar displays, and conflict resolution aid (CRA) are proposed for the enhancement of the current air traffic control (ATC) systems. To evaluate the proposed ATC systems, questionnaires are commonly used to get the feedback from ATCOs. However, the questionnaires are usually administered upon completion of each ATC simulation task thus provide only overall ratings towards the new ATC systems. In this paper, we propose and implement a novel Electroencephalogram (EEG)-based neurocognitive tools for evaluation of ATC systems. The nature of EEG-based technique is that the brain states can be monitored in a high resolution time, fitting the nature of time-critical ATC tasks. Thus, such EEG-based human factors study allows for real-time monitoring of ATCOs’ mental workload during the task performance in ATC systems. We designed and conducted an experiment to evaluate the costs and benefits of the CRA and tactile user interface in future ATC systems. Thirty six participants participated in the experiment and were assigned into three groups of different display modes: Non-Display, Display, and Trajectory Prediction. In each group, three CRA conditions were given: Manual, Reliable and Unreliable. The EEG data were recorded during the tasks, and the traditional workload evaluation method NASA Task Load Index (TLX) was administered at the end of each task. The result shows that the ratings obtained from NASA TLX and from the EEG labeling are highly correlated. Thus, the EEG-based system is reliable to recognize workload during the task performance. With the proposed EEG-based system, we found that 1) relatively high workload was observed at the beginning of the experiment in each group which could be due to participants’ unfamiliarity with the interfaces; 2) participants in the trajectory prediction group had much higher workload as compared to vertical display and non-display groups, which could be attributed to its complexity. The changes of workload are due to interaction between the type of display modes and time (p<0.05); 3) workload varied slightly with different CRA setting. The results show that the proposed EEG-based system for human factors study can provide better understanding of real-time mental workload changes during the task performance in new ATC systems, therefore enables the evaluation of current and future ATC systems.

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

2017

Proceedings Web3D 2017

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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Roth, Daniel; Stork, André [1. Gutachten]; Weber, Daniel [2. Gutachten]

Efficient Methods for Nonlinear Materials for Interactive Deformation Simulations based on Finite Elements

2017

Darmstadt, TU, Master Thesis, 2017

This thesis evolves around the interactive simulation of deformable objects with the finite element method. It is focused on the case where the underlying material model is nonlinear. It is analyzed which parameter influence interactivity and how much detail w.r.t. discretization is possible. Another challenging task is how to handle inversions. In this thesis an approach is developed that efficiently deals with those. Implicit time integration is necessary to guarantee stability with large time steps. Here, nonlinear materials require the solution of a nonlinear system in each time step. There is no guarantee that iterative solvers converge in those systems. For that reason, stabilization methods are developed that improve the convergence. A nonlinear material model for the simulation of a muscle is implemented and optimized. It is compared to a linearized model to gain a better understanding of the impacts of linearization.

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Efficient Pose Selection for Interactive Camera Calibration

2017

Adjunct Proceedings of the 2017 IEEE International Symposium on Mixed and Augmented Reality

IEEE International Symposium on Mixed and Augmented Reality (ISMAR) <16, 2017, Nantes, France>

The choice of poses for camera calibration with planar patterns is only rarely considered - yet the calibration precision heavily depend on it. This work presents a pose selection method that explicitly avoids singular pose configurations which would lead to an unreliable solution. Consequently camera poses are favoured that reduce the uncertainty of the calibration parameters most. For this purpose the quality of the calibration parameters is continuously estimated using uncertainty propagation. Our approach performs better than comparable solutions while requiring 30% less calibration frames.

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Efficient, Accurate, and Rotation-Invariant Iris Code

2017

IEEE Signal Processing Letters

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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Hartl, Tabea; Kuijper, Arjan [1. Gutachten]; Jung, Florian [2. Gutachten]

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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Joshi, Dhanashree Jayant; Kuijper, Arjan [1. Gutachten]; Rus, Silvia [2. Gutachten]

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

Ambient Assisted Living

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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Zafar, Abdul Rehman; Kuijper, Arjan [1. Gutachter]; Ben Hmida, Helmi [2. Gutachter]

Enhancing User Experience in Internet of Things Systems in terms of Smart Rule Management

2017

Darmstadt, TU, Master Thesis, 2017

The number of devices in the Internet of Things systems is increasing day by day. With this increase in the number of devices, more and more data is being produced everyday. The quality of life of the end user is improving by using this data more efficiently. These data events are used to track any change in the state of smart devices. The applications of such systems include smart homes, health monitoring , traffic monitoring , energy consumption , logistics etc. More sophisticated systems are needed which can make sense of the data and perform right actions. Hence, a rule management layer is needed to effectively process these events. However, in the traditional systems, these programs are only written in the back-end by the developer of the application and are triggered automatically. So the end user of the application never has access or has very minimal interface to view and manage the rules. More human involvement contributes to success of an IoT system. Technically naive users usually view the whole IoT system in terms of user interface. Lacking the ability to visualize the rules greatly reduces the user acceptance of such systems and such systems are more likely to fail. That is why we should bring this rule management part to the front end of the system, rather than the back-end as it always has been in the traditional IoT systems. Thus, we need to increase the human acceptance of such systems by enhancing the user experience with a more user-friendly rule management system. Having such power for an ordinary end user is life changing. This thesis focus on enhanced the the user experience with respect to rules management in IoT systems. This has been done by reducing the complexity for technically naive end users and giving more flexibility to the technical users. This combination enhances the overall user experience and user acceptance with respect to rules management in IoT systems.

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Jakate, Sufyaan Chand; Kuijper, Arjan [1. Gutachter]; Ben Hmida, Helmi [2. Gutachter]

Enhancing User Experience with respect to Device Management in Internet of Things Domain

2017

Darmstadt, TU, Master Thesis, 2017

There has been a steady increase in the use and development of the IoT devices. This is due to the increasing capabilities of the IoT devices and companies desire to provide better and easy services to the IoT users. An IoT system consists of multiple devices, which work, in cooperation to provide different services to the users. Since the numbers of IoT devices are increasing in the system, it is becoming difficult to manage all the IoT devices in the existing system. Consider the example of a Home IoT System, which consists of hundreds of devices, and sensors, which work in collaboration to provide the services. The management of large number of devices for a novice end user will be very challenging and complex task. The primary focus of this thesis is simplifying and reducing the complexity of managing the IoT devices with perspective of the novice end users, thus enhancing the overall experience for the end users.

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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

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

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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Fu, Biying; Gangatharan, Dinesh Vaithyalingam; Kuijper, Arjan; Kirchbuchner, Florian; Braun, Andreas

Exercise Monitoring On Consumer Smart Phones Using Ultrasonic Sensing

2017

iWOAR 2017

International Workshop on Sensor-based Activity Recognition (iWOAR) <4, 2017, Rostock, Germany>

Quantified self has been a trend over the last several years. An increasing number of people use devices, such as smartwatches or smartphones to log activities of daily life, including step count or vital information. However, most of these devices have to be worn by the user during the activities, as they rely on integrated motion sensors. Our goal is to create a technology that enables similar precision with remote sensing, based on common sensors installed in every smartphone, in order to enable ubiquitous application. We have created a system that uses the Doppler effect in ultrasound frequencies to detect motion around the smartphone. We propose a novel use case to track exercises, based on several feature extraction methods and machine learning classification. We conducted a study with 14 users, achieving an accuracy between 73% and 92% for the different exercises.

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Dimitrov, Kristiyan; Kuijper, Arjan [Advisor]; Damer, Naser [Supervisor]

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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Fiber Defect Detection of Inhomogeneous Voluminous Textiles

2017

Pattern Recognition

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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Flow Shop Scheduling Problem and Solution in Cooperative Robotics - Case-Study: One Cobot in Cooperation with One Worker

2017

Future Internet

This research combines between two different manufacturing concepts. On the one hand, flow shop scheduling is a well-known problem in production systems. The problem appears when a group of jobs shares the same processing sequence on two or more machines sequentially. Flow shop scheduling tries to find the appropriate solution to optimize the sequence order of this group of jobs over the existing machines. The goal of flow shop scheduling is to obtain the continuity of the flow of the jobs over the machines. This can be obtained by minimizing the delays between two consequent jobs, therefore the overall makespan can be minimized. On the other hand, collaborative robotics is a relatively recent approach in production where a collaborative robot (cobot) is capable of a close proximity cooperation with the human worker to increase the manufacturing agility and flexibility. The simplest case-study of a collaborative workcell is one cobot in cooperation with one worker. This collaborative workcell can be seen as a special case of the shop flow scheduling problem, where the required time from the worker to perform a specific job is unknown and variable. Therefore, during this research, we implement an intelligent control solution which can optimize the flow shop scheduling problem over the previously mentioned case-study.

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Papaioannou, Georgios; Schreck, Tobias; Andreadis, Andreadis; Mavridis, Pavlos; Gregor, Robert; Sipiran, Ivan; Vardis, Konstantinos

From Reassembly to Object Completion: A Complete Systems Pipeline

2017

ACM Journal on Computing and Cultural Heritage

The problem of the restoration of broken artifacts, where large parts could be missing, is of high importance in archaeology. The typical manual restoration can become a tedious and error-prone process, which also does not scale well. In recent years, many methods have been proposed for assisting the process, most of which target specialized object types or operate under very strict constraints. We propose a digital shape restoration pipeline consisting of proven, robust methods for automatic fragment reassembly and shape completion of generic three-dimensional objects of arbitrary type. In this pipeline, first we introduce a novel unified approach for handling the reassembly of objects from heavily damaged fragments by exploiting both fracture surfaces and salient features on the intact sides of fragments, when available. Second, we propose an object completion procedure based on generalized symmetries and a complementary part extraction process that is suitable for driving the fabrication of missing geometry. We demonstrate the effectiveness of our approach using real-world fractured objects and software implemented as part of the European Union-funded PRESIOUS project, which is also available for download from the project site.

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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

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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Fellner, Dieter W. [General Co-Chair / Proceedings Production Ed.]; Habsburg-Lothringen, Bettina [General Co-Chair]; Schreck, Tobias [Program Co-Chair]; Weyrich, Tim [Program Co-Chair]; Sablatnig, Robert [Short Paper Co-Chair]; Stular, Benjamin [Short Paper Co-Chair]; Ullrich, Torsten [Local Chair]

GCH 2017

2017

Eurographics Workshop on Graphics and Cultural Heritage (GCH) <15, 2017, Graz, Austria>

The 15th EUROGRAPHICS Workshop on Graphics and Cultural Heritage (GCH 2017) was organized by the Institute of Computer Graphics and Knowledge Visualization, Graz University of Technology and by Fraunhofer Austria. It aimed to foster an international dialogue between ICT experts and CH scientists to advance the understanding of critical requirements for processing, managing, and delivering cultural information to a broad audience. To advance the dialogue between ICT and CH experts, GCH'17 was held in close cooperation with the Museumsakademie of the Universalmuseum Joanneum in Graz, providing ample opportunity for exchange between the domains.

  • 978-3-03868-037-6
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General Borda Count for Multi-biometric Retrieval

2017

2017 International Joint Conference on Biometrics

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

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 - Effiziente Prozesskette für 3D-Computergraphik".

  • 978-3-8396-1228-6
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Daza Parra, Laura Milena; Matthies, Denys J.C. [Supervisor]; Urban, Bodo [Supervisor]

Going Beyond Scalable Notifcations - from Subtle Stimulus to Forced Response

2017

Rostock, Univ., Master Thesis, 2017

People's perception of their own body's appearance, capabilities and position are constantly updated through sensory cues that are naturally produced by their own actions. Alteration or enhancement of such cues has been carried out with multisensory feedback in multiple Human Computer Interaction (HCI) areas such as health, psychology, neuroscience and games. HCI applications use normally audible or visual alerts, such as LEDs, beeps, bells, among others. However haptic feedback (related to the sense of touch) uses normally other components to augment or replace such common alert methods. Such alerts, also called notifications, usually stick to a binary level of information, while they are either attention drawing or silent. This work proposes a concept that goes beyond scalable notifications, reaching from subtle to obtrusive and also forcing the user to take action. To illustrate the technical feasibility and validity of the concept, three prototypes were developed providing vibrotactile, thermal, and electrical feedback. Each prototype was evaluated in different lab settings suggesting that the concept is applicable in the given situations. It is shown the effect of different notification levels while completing a task and how going beyond an obtrusive level forces the user to execute a desired action such as correct their posture, stop using a tool or press down the gas pedal completely.

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Frank, Sebastian; Kuijper, Arjan

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

2017

Ambient Intelligence

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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Scherf, Lisa Katharina; Kuijper, Arjan [1. Gutachten]; Kirchbuchner, Florian [2. Gutachten]

Human Behavior Analysis and Prediction Based on a Smart Floor

2017

Darmstadt, TU, Bachelor Thesis, 2017

Older adults have the desire to live independently in their own homes for as long as possible. The development of sensor technologies in Smart Homes support this aim by providing sufficient security standards in case of emergencies. For example, a call of emergency can be triggered if a fall of a person is detected by sensors hidden in the floor. However, it is often not only about urgent situations, but also about gradual changes in behavior. Especially when a user is not able to follow his or her daily routine, long-term activity recognition based on location tracking allows for early detection of diseases such as Alzheimer's and dementia and can generally reveal a decrease in the ability to live independently. The focus of this work was the investigation of health related activities and their most accurate measurement only using an intelligent floor based system. Based on these considerations, a method to extrapolate from the collected sensor data to the chosen values is proposed. In addition, a model to detect gradual changes in these health indicators is developed and tested on the smart floor in the Living Lab of Fraunhofer IGD as well as in two apartments in everyday life. The findings of these thesis show a way of using smart floors for health monitoring. The applicability in everyday life could not be shown due to independent problems with the location tracking of the floor during the evaluation period and the lack of additional data for the validation. However, the evaluation under testing conditions showed promising results and an untapped potential of smart floors in health monitoring.

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Implicit Mesh Generation Using Volumetric Subdivision

2017

VRIPHYS 17: 13th Workshop in Virtual Reality Interactions and Physical Simulations

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

2017

Hydro International

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 [1. Gutachter]; Braun, Andreas [2. Gutachter]; 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

Computer Analysis of Images and Patterns

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

Ambient Intelligence

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 [1. Gutachter]; 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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Integrating Interactive Design and Simulation for Mass Customized 3D-Printed Objects - A Cup Holder Example

2017

Solid Freeform Fabrication 2017: Proceedings of the 28th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference

Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference <28, 2017, Austin, USA>

We present an approach for integrating interactive design and simulation for customizing parameterized 3D models. Instead of manipulating the mesh directly, a simplified interface for casual users allows for adapting intuitive parameters, such as handle diameter or height of our example object - a cup holder. The transition between modeling and simulation is performed with a volumetric subdivision representation, allowing direct adaption of the simulation mesh without re-meshing. Our GPU-based FEM solver calculates deformation and stresses for the current parameter configuration within seconds with a pre-defined load case. If the physical constraints are met, our system allows the user to 3D print the object. Otherwise, it provides guidance which parameters to change to optimize stability while adding as little material as possible based on a finite differences optimization approach. The speed of our GPU-solver and the fluent transition between design and simulation renders the system interactive, requiring no pre-computation.

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Riffnaller-Schiefer, Andreas; Augsdörfer, Ursula H.; Fellner, Dieter W.

Interactive Physics-Based Deformation for Virtual Worlds

2017

2017 International Conference on Cyberworlds

International Conference on Cyberworlds (CW) <2017, Chester, UK>

When creating immersive interactive virtual worlds, it is important to not only provide plausible visuals, but also to allow the user to interact with the virtual scene in a natural way. While rigid-body physics simulations are widely used to provide basic interaction, realistic soft-body deformations of virtual objects are challenging and therefore typically not offered. We present a client-server architecture for interactive physicsbased deformation, which makes it possible to add physically accurate response to interaction to any virtual environment. The architecture is highly flexible, can be used from any web enabled client, and facilitates synchronization of computed deformations across multiple users and devices.

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Shao, Lin; Mahajan, A.; Schreck, Tobias; Lehmann, D.J.

Interactive Regression Lens for Exploring Scatter Plots

2017

Computer Graphics Forum

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

Data analysis often involves finding models that can explain patterns in data, and reduce possibly large data sets to more compact model-based representations. In Statistics, many methods are available to compute model information. Among others, regression models are widely used to explain data. However, regression analysis typically searches for the best model based on the global distribution of data. On the other hand, a data set may be partitioned into subsets, each requiring individual models. While automatic data subsetting methods exist, these often require parameters or domain knowledge to work with. We propose a system for visual-interactive regression analysis for scatter plot data, supporting both global and local regression modeling. We introduce a novel regression lens concept, allowing a user to interactively select a portion of data, on which regression analysis is run in interactive time. The lens gives encompassing visual feedback on the quality of candidate models as it is interactively navigated across the input data. While our regression lens can be used for fully interactive modeling, we also provide user guidance suggesting appropriate models and data subsets, by means of regression quality scores. We show, by means of use cases, that our regression lens is an effective tool for user-driven regression modeling and supports model understanding.

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Patzwahl, Alex; Kuijper, Arjan [1. Prüfer]; Brodkorb, Felix [2. Prüfer]

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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International Conference on Knowledge Technologies and Data-driven Business 2017 (i-KNOW 2017) - Workshop Proceedings

2017

International Conference on Knowledge Technologies and Data-Driven Business <2017, Graz, Austria>

CEUR Workshop Proceedings
2025
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Invisible Human Sensing in Smart Living Environments Using Capacitive Sensors

2017

Ambient Assisted Living

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. [Hrsg.]; Baier, Konrad [Red.]; Ackeren, Janine van [Red.]; Alexandrin, Max [Red.]; Barth, Anna [Red.]; Bockholt, Ulrich [Red.]; Kopold, Franziska [Red.]; Löwer, Chris [Red.]; May, Thorsten [Red.]; Peters, Wiebke [Red.]; Wehner, Detlef [Red.]; Gollnast, Anja [Gestaltung]; Bumke, Carina [Gestaltung]

Jahresbericht 2016

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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Marine Snow Detection and Removal: Underwater Image Restoration using Background Modeling

2017

WSCG 2017. Full Papers Proceedings

International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision (WSCG) <25, 2017, Plzen, Czech Republic>

It is a common problem that images captured underwater (UW) are corrupted by noise. This is due to the light absorption and scattering by the marine environment; therefore, the visibility distance is limited up to few meters. Despite blur, haze, low contrast, non-uniform lightening and color cast which occasionally are termed noise, additive noises, such as sensor noise, are the center of attention of denoising algorithms. However, visibility of UW scenes is distorted by another source termed marine snow. This signal not only distorts the scene visibility by its presence but also disturbs the performance of advanced image processing algorithms such as segmentation, classification or detection. In this article, we propose a new method that removes marine snow from successive frames of videos recorded UW. This method utilizes the characteristics of such a phenomenon and detects it in each frame. In the meanwhile, using a background modeling algorithm, a reference image is obtained. Employing this image as a training data, we learn some prior information of the scene and finally, using these priors together with an inpainting algorithm, marine snow is eliminated by restoring the scene behind the particles.

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Weber, Nicolas; Goesele, Michael

MATOG: Array Layout Auto-Tuning for CUDA

2017

ACM Transactions on Architecture and Code Optimization

Optimal code performance is (besides correctness and accuracy) the most important objective in compute intensive applications. In many of these applications, Graphic Processing Units (GPUs) are used because of their high amount of compute power. However, caused by their massively parallel architecture, the code has to be specifically adjusted to the underlying hardware to achieve optimal performance and therefore has to be reoptimized for each new generation. In reality, this is usually not the case as productive code is normally at least several years old and nobody has the time to continuously adjust existing code to new hardware. In recent years more and more approaches have emerged that automatically tune the performance of applications toward the underlying hardware. In this article, we present the MATOG auto-tuner and its concepts. It abstracts the array memory access in CUDA applications and automatically optimizes the code according to the used GPUs. MATOG only requires few profiling runs to analyze even complex applications, while achieving significant speedups over non-optimized code, independent of the used GPU generation and without the need to manually tune the code.

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Do Nascimento Melo, Ana Carolina; Jahnke, Matthias [Supervisor]; Knippers, Richard [Supervisor]; Domajnko, Matevz [Supervisor]

Methodology for Evaluation of Precision and Accuracy of Different Geometric 3D Data Acquisition Methods

2017

München, TU, Master Thesis, 2017

3D optical scanning systems have been gaining considerable space in metrology, being largely applied in industry sectors and in the cultural heritage domain. The amount of available sensors on the market has grown considerably. Thereby, deciding for the right technique that fits-to-a-purpose or the most cost efficient technology, is a challenging task. When deciding in which technology to invest, the user often relies on the manufacturer’s instructions. However, manufacturers generally do not state under which conditions such values were acquired and thus, the system’s reproducibility is not assured. If measurements could be traced back to a common standard, this problem could be easily addressed. As such a solution is still not available, specialist often tend to solve this issue by associating terms like precision, accuracy and uncertainty to a measurement. Nowadays, the most applicable solution to define the accuracy of a system relies on the VDI/VDE 2634. This master thesis aims to develop a common solution to assess accuracy for different geometric 3D data acquisition models, considering the specifications of the VDI/VDE 2634 Part 3. The methodology proposed here encompasses the entire process from the acquisition to its processing stage. The study-case comprehend triangulated methods, as photogrammetry and laser line sensor. During the acquisition, a calibrated probing body and adapted test are proposed. The processing stage includes a best-fit algorithm and an evaluation of measurement uncertainty. The result comprehends the quality parameters together with the visualization of measurement uncertainty supporting the entire system. Therefore, providing to the end user enough information about the capability of the evaluated system.

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Hur, Junhwa; Roth, Stefan

MirrorFlow: Exploiting Symmetries in Joint Optical Flow and Occlusion Estimation

2017

2017 IEEE International Conference on Computer Vision

IEEE International Conference on Computer Vision (ICCV) <16, 2017, Venice, Italy>

Optical flow estimation is one of the most studied problems in computer vision, yet recent benchmark datasets continue to reveal problem areas of today's approaches. Occlusions have remained one of the key challenges. In this paper, we propose a symmetric optical flow method to address the well-known chicken-and-egg relation between optical flow and occlusions. In contrast to many state-of-the-art methods that consider occlusions as outliers, possibly filtered out during post-processing, we highlight the importance of joint occlusion reasoning in the optimization and show how to utilize occlusion as an important cue for estimating optical flow. The key feature of our model is to fully exploit the symmetry properties that characterize optical flow and occlusions in the two consecutive images. Specifically through utilizing forward-backward consistency and occlusion-disocclusion symmetry in the energy, our model jointly estimates optical flow in both forward and backward direction, as well as consistent occlusion maps in both views. We demonstrate significant performance benefits on standard benchmarks, especially from the occlusion-disocclusion symmetry. On the challenging KITTI dataset we report the most accurate two-frame results to date.

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Yeo, Lee Guan; Sun, Haoqi; Liu, Yisi; Trapsilawati, Fitri; Sourina, Olga; Chen, Chun-Hsien; Müller-Wittig, Wolfgang K.; Ang, Wei Tech

Mobile EEG-based Situation Awareness Recognition for Air Traffic Controllers

2017

Proceedings 2017 IEEE International Conference on Systems, Man, and Cybernetics

IEEE International Conference on Systems, Man and Cybernetics (SMC) <2017, Banff, Canada>

With the growing volume and complexity of air traffic, air traffic controllers (ATCOs) encounter heavier burden nowadays. Therefore, human factors study in air traffic control (ATC) is increasingly essential, paving the way to a safer air transportation system. In this paper, we conducted an ATC experiment, where Electroencephalogram (EEG) data were collected throughout the experiment. Compared to traditional questionnaires and psychological tests used in human factors study, the proposed novel EEG approach provides monitoring of situation awareness (SA) in a non-invasive and non-interruptive fashion. SA was represented as the response latency in situation present assessment method (SPAM), which was predicted from EEG signals using three machine learning algorithms. Support vector regression obtained the lowest prediction error of 1.5 seconds, which is lower than 10% of the range of actual response latency. The results show that EEG is a promising approach forward in measuring situation awareness of ATCOs in both real-time and accurate manner.

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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

Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie

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

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

Pattern Recognition and Image Analysis

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 [Referent]; Stiemerling, Martin [Korreferent]; 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

Ambient Intelligence

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

Ambient Assisted Living

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 [Gutachter]

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

Medical Image Computing and Computer Assisted Intervention - MICCAI 2017: Part I

International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI) <20, 2017, Québec City, QC, 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

Go-3D 2017: Mit 3D Richtung Maritim 4.0

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

Ambient Intelligence

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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Sadik, Ahmed R.; Taramov, Andrei; Urban, Bodo

Optimization of Tasks Scheduling in Cooperative Robotics Manufacturing via Johnson's Algorithm

2017

2017 IEEE Conference on Systems, Process and Control (ICSPC 2017)

IEEE Conference on Systems, Process and Control (ICSPC) <2017, Melaka, Malaysia>

The rapid development of information technology in the last half century led to the emergence of a new industrial revolution, often called Industry 4.0, the key element of which is the introduction of informatization in all spheres of human life and the widespread use of cyberphysical systems. The main attribute of such systems is the interaction of human and smart machines, this approach allows achieving the greatest flexibility and productivity simultaneously. The latest example of such systems is the collaborative manufacturing system, where the human worker cooperates in a close distance with a collaborative robot (cobot) in a production scenario. This cooperation is applicable when the final product requires a high degree of customization that a worker can provide, while cooperation with the cobot is greatly speeding up the productivity. In this context, one of the actual problems is to schedule the cooperative tasks in real time among the operational resources (i.e., the workers and cobots). This problem can be reduced to a special case of the flow-shop scheduling problem. The complexity of this problem increases with increasing the number of cooperative operational resources and the production steps. Undoubtedly, modern production often involves several processing steps serviced by several operational resources. Therefore, it is necessary to study a complex cooperative manufacturing scenario. The simplest and most understandable case scenario is the interaction of two workers and one cobot in two stages production workcell. Thus, in this paper we will consider the implementation of this casestudy using the available scheduling algorithms.

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Ritter, Christian; Kuijper, Arjan [1. Gutachten]; Bernard, Jürgen [2. Gutachten]

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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Wannenwetsch, Anne S.; Roth, Stefan; Keuper, Margret

ProbFlow: Joint Optical Flow and Uncertainty Estimation

2017

2017 IEEE International Conference on Computer Vision

IEEE International Conference on Computer Vision (ICCV) <16, 2017, Venice, Italy>

Optical flow estimation remains challenging due to untextured areas, motion boundaries, occlusions, and more. Thus, the estimated flow is not equally reliable across the image. To that end, post-hoc confidence measures have been introduced to assess the per-pixel reliability of the flow. We overcome the artificial separation of optical flow and confidence estimation by introducing a method that jointly predicts optical flow and its underlying uncertainty. Starting from common energy-based formulations, we rely on the corresponding posterior distribution of the flow given the images. We derive a variational inference scheme based on mean field, which incorporates best practices from energy minimization. An uncertainty measure is obtained along the flow at every pixel as the (marginal) entropy of the variational distribution. We demonstrate the flexibility of our probabilistic approach by applying it to two different energies and on two benchmarks. We not only obtain flow results that are competitive with the underlying energy minimization approach, but also a reliable uncertainty measure that significantly outperforms existing post-hoc approaches.

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

Procedural Modeling of Architecture with Round Geometry

2017

Computers & Graphics

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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Papaefthymiou, M.; Nikolakopoulou, V.; Leventis, G.; Domajnko, Matevz; Ioannides, Marinos; Papagiannakis, G.; Santos, Pedro

Projecting our Past to the Future - Challenges and Results: The Case of Asinou Church

2017

GCH 2017

Eurographics Workshop on Graphics and Cultural Heritage (GCH) <15, 2017, Graz, Austria>

In this paper, we present some of the novel results of the Marie Curie Initial Training Network for Digital Cultural Heritage (ITN-DCH) project, describing briefly the work done focusing on the project's first case study: the Panagia Phorviotisa of Asinou, an UNESCO World Heritage Listed (WHL) monument in Cyprus. The paper introduces some challenges and the importance of multidisciplinary, sustainable research and development in the emerging domain of DCH in Europe. The different methodologies address these challenges through a professional network of partners including Academia, Research and Industry. The paper describes the 3D documentation of the church and how the data acquired can be used and re-used in Mixed Reality (MR) applications using also Deep Learning techniques, as well as in Education.

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Reinert, David; Humm, Bernhard [Referent]; Rapp, Stefan [Korreferent]; 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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Knuth, Martin; Fellner, Dieter W. [Referent]; Bender, Jan [Referent]

Realistic Visualization of Accessories within Interactive Simulation Systems for Garment Prototyping

2017

Darmstadt, TU, Diss., 2017

In virtual garment prototyping, designers create a garment design by using Computer Aided Design (CAD). In difference to traditional CAD the word "aided" in this case refers to the computer replicating real world behavior of garments. This allows the designer to interact naturally with his design. The designer has a wide range of expressions within his work. This is done by defining details on a garment which are not limited to the type of cloth used. The way how cloth patterns are sewn together and the style and usage of details of the cloth's surface, like appliqués, have a strong impact on the visual appearance of a garment to a large degree. Therefore, virtual and real garments usually have a lot of such surface details. Interactive virtual garment prototyping itself is an interdisciplinary field. Several problems have to be solved to create an efficiently usable real-time virtual prototyping system for garment manufacturers. Such a system can be roughly separated into three sub-components. The first component deals with acquisition of material and other data needed to let a simulation mimic plausible real world behavior of the garment. The second component is the garment simulation process itself. Finally, the third component is centered on the visualization of the simulation results. Therefore, the overall process spans several scientific areas which have to take into account the needs of each other in order to get an overall interactive system. In my work I especially target the third section, which deals with the visualization. On the scientific side, the developments in the last years have shown great improvements on both speed and reliability of simulation and rendering approaches suitable for the virtual prototyping of garments. However, with the currently existing approaches there are still many problems to be solved, especially if interactive simulation and visualization need to work together and many object and surface details come into play. This is the case when using a virtual prototyping in a productive environment. The currently available approaches try to handle most of the surface details as part of the simulation. This generates a lot of data early in the pipeline which needs to be transferred and processed, requiring a lot of processing time and easily stalls the pipeline defined by the simulation and visualization system. Additionally, real world garment examples are already complicated in their cloth arrangement alone. This requires additional computational power. Therefore, the interactive garment simulation tends to lose its capability to allow interactive handling of the garment. In my work I present a solution, which solves this problem by moving the handling of design details from the simulation stage entirely to a completely GPU based rendering stage. This way, the behavior of the garment and its visual appearance are separated. Therefore, the simulation part can fully concentrate on simulating the fabric behavior, while the visualization handles the placing of surface details lighting, materials and self-shadowing. Thus, a much higher degree of surface complexity can be achieved within an interactive virtual prototyping system as can be done with the current existing approaches.

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Rixels: Towards Secure Interactive 3D Graphics in Engineering Clouds

2017

Go-3D 2017: Mit 3D Richtung Maritim 4.0

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 [1. Gutachten]; Limper, Max [2. Gutachter]

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

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

Ambient Intelligence

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

Proceedings of the 10th International Conference on PErvasive Technologies Related to Assistive Environments

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]

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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Bauer, Christoph; Kuijper, Arjan [1. Gutachten]; Fauser, Johannes [2. Gutachten]

Segmentierung des Unterkiefergelenks und der Mastoidzellen in CT-Daten des Felsenbeins

2017

Darmstadt, TU, Bachelor Thesis, 2017

For a tissue-conserving operation at the otobasis it is often helpful to make an exact planning with 3d models before the operation. For the creation of such 3d models an exact segmentation of the structures in the area of the otobasis is needed. Those structures are segmented of medical images. For the segmentation of the petrous bone with the mastoid part an algorithm was already created, however this algorithm has problems with the segmentation of mastoid cells and with the removal of the lower jaw. This work addresses these problems and segments the lower jaw was well as the mastoid cells within the petrous bone. Additionally, an algorithm for the detection of the external auditory canal is described which leads to a better automatic initialization. The segmentation uses 3d greyscale images of the temporal bone together with the mention of the side of the temporal bone. The segmentation uses a combination of image-based and form-based segmentation algorithms.

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Sajenko, Andrej; Letschert, Thomas [Referent]; Krämer, Michel [Korreferent]

Seminaturliche Abfragesprache fur GeoDaten

2017

Gießen, TH Mittelhessen, Master Thesis, 2017

Diese Arbeit befasst sich mit der Entwicklung einer seminatürlichen Abfragesprache, mit welcher Merkmale eines geografischen Features beschrieben werden. Das Suchverhalten wird so verändert, dass gesuchte Begriffe semantisch verglichen werden. Der Vergleich zwischen Wörtern des Benutzers und den Bezeichnern des Indexes wird auf den Wortstamm und deren Synonyme verallgemeinert, um dem Benutzer mehr Freiheiten in der Wortwahl zu geben. Die Abfragesprache besteht aus einer Teilmenge an natürlichsprachlichen, einfachen Sätzen und bietet die Möglichkeit einfache Eingrenzungen der Ergebnisse vorzunehmen. Der Benutzer wird durch das Interface mittels Vorschlagen und Vervollständigungen unterstutzt, um die Syntax richtig zu treffen. Die Einbeziehung der Synonyme stellt sich als sinnvoll heraus. Dies regt dazu an weitere Beziehungen wie die Holonyme zu nutzen um den semantischen Vergleich weiter auszubauen. Eine pragmatische Losung für einfache Abfragen mit konjugierten Bedingungen liefert die seminatürliche Abfragesprache. Für einen professionellen Einsatz ist die Sprache unzureichend, da diese keine logischen "und" und "oder" Verknüpfungen zulasst. Die Eingabeunterstützung sorgt dafür, dass Benutzer ihre Abfragen durch die Auswahl der Vorschläge strukturell zusammenstellen können ohne einen syntaktischen Fehler zu erhalten.

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Madapur Devraj, Sudeep Dev; Kraus, Dieter [Supervisor]; Siegmund, Dirk [Supervisor]

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 [1. Gutachten]; Getto, Roman [2. Gutachten]

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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Manjunath, Nagarjun; Kraus, Dieter [Supervisor]; Rus, Silvia [Supervisor]

Simulation and Validation of Capacitive Sensing on Flexible and Curved Surfaces Applied on Sleeping Breathing Rate Detection

2017

Bremen, Hochschule, Master Thesis, 2017

In recent years the capacitive sensing is the main technology, act as input in smart devices. There will be limitations for the flat surface, and nowadays people wants to use flexible surface input devices such as foldable mobiles, flexible input devices, and curved input devices. For these input devices, the surface wants to be flexible and curved; limited research has been carried out till now on curved and flexible surface capacitive sensing technology. The main objective of this master thesis is to investigate the capacitive sensing for different materials, different flexibility, and curvature. Simulation and validation of capacitive sensing on flexible and curved surfaces for various materials are carried out. Moreover, designing an own application (Breathing rate detection while sleeping) based on the characteristics obtained by capacitive sensing for various material on the flexible and curved surface.

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

2017

VISAPP 2017. Proceedings

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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Trimpop, John; Schenk, Hannes; Bieber, Gerald; Lämmel, Friedrich; Burggraf, Paul

Smartwatch based Respiratory Rate and Breathing Pattern Recognition in an End-consumer Environment

2017

iWOAR 2017

International Workshop on Sensor-based Activity Recognition (iWOAR) <4, 2017, Rostock, Germany>

Smartwatches as wearables became part of social life and practically and technically offer the possibility to collect medical body parameters next to usual fitness data. In this paper, we present an evaluation of the respiratory rate detection of the &gesund system. &gesund is a health assistance system, which automatically records detailed long-term health data with end-consumer smartwatches. The &gesund core is based on technology exclusively licensed from the Fraunhofer Institute of applied research. In our study, we compare the &gesund algorithms for respiration parameter detection in low-amplitude activities against data recorded from actual sleep laboratory patients. The results show accuracies of up to 89%. We are confident that wearable technologies will be used for medical health assistance in the near future.

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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

Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie

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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Schinko, Christoph; Riffnaller-Schiefer, Andreas; Krispel, Ulrich; Eggeling, Eva; Ullrich, Torsten

State-of-the-Art Overview on 3D Model Representations and Transformations in the Context of Computer-Aided Design

2017

International Journal on Advances in Software

Within a virtual world, either in virtual reality or in a simulation environment, the digital counterparts of real objects are described by mathematical and computational models. Depending on the purpose, the field of application, and the used toolchain a wide variety of model representations is established. As a consequence, conversion methods and transformation algorithms are becoming increasingly important. This article gives a state of the art overview on model representations and on the most important transformation techniques.

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Mettel, Matthias Ruben; Kuijper, Arjan [1. Gutachten]; Braun, Andreas [2. Gutachten]

Surface Acoustic Arrays to Analyze Human Activities in Smart Environments

2017

Darmstadt, TU, Master Thesis, 2017

This thesis introduces an approach for tracking three different activities, including their context extension, with a precision of 94% by using multiple pickup/piezo sensors. The mechanical waves, which are created by people touching various objects, can be recognized with these sensors. The combination of classical signal processing and current methods of machine learning enables the implementation of a processing pipeline for classifying these signal events and assigning the propagated event signal to its activity. Compared to the C4.5 CART and BayesNET classifiers,the best precision and performance balance is offered by the SVM classifier. The observed activities in this thesis are Walking, Closing a Cupboard and Falling. Especially Walking and Closing a Cupboard provide a good basis for extending the context. For a context expansion of Walking, the classification classes are split into the shoe types. Closing a Cupboard is divided into the cupboard instances, which have different positions and facing directions, in the environment. To avoid creating a Non class an Impact Filter is applied for preprocessing the recorded signals. The utilized main features are the RMS value and the Zero Crossings of the time-domain signal. They are extended by the FFT vector, statistical values like the mean and standard derivation of this vector as well as the index of the maximal FFT value. With this results, it is possible to lower the issues with common sensors like wearables and cameras. An additional advantage is that it can very easily be integrated in any environment.

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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

2017 IEEE 41st Annual Computer Software and Applications Conference Workshops

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

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 3× to 531×, for sufficiently large meshes, while reducing memory consumption by up to 36%.

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Gutbell, Ralf; Kühnel, Hannes; Kuijper, Arjan

Texturizing and Refinement of 3D City Models with Mobile Devices

2017

Advanced Concepts for Intelligent Vision Systems

International Conference on Advanced Concepts for Intelligent Vision Systems (ACIVS) <18, 2017, Antwerp, Belgium>

Building recognition from images and video streams of mobile devices to texturize and refine an existing 3D city model is an open challenge, since such models most often do not completely represent the actual buildings. We present ways to extract buildings from images enabling improvement of the existing model. The approach is based on edge detection on images to detect walls, pure use of sensor data by creating an overlay to the video stream with the 3D model renderer from current position by a server, and the use of structure from motion algorithms to create point clouds and recognize a building via the support of the device's sensors. We show that we are thus able to texturize and refine an existing 3D city model.

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Holm, Håvard Heitlo; Gezer, Volkan; Hermawati, Setia; Altenhofen, Christian; Hjelmervik, Jon M.

The CloudFlow Infrastructure for Multi-Vendor Engineering Workflows: Concept and Validation

2017

International Journal on Advances in Internet Technology

In this paper, we present the CloudFlow Infrastructure, which aims to provide an independent platform for engineering workflows, leveraging both cloud and high performance computing. Each workflow can combine software from different vendors, promoting interoperability through open standards, and easy access to data and compute resources. Here, we focus on the technological uniqueness of the infrastructure, and how end users within the manufacturing industries have validated it for real world applications. We also describe how high performance computing and remote desktop applications easily are integrated in cloud-enabled workflows. The infrastructure provides an easyto- use platform for software providers to offer their software in the cloud and get access to a new distribution channel. At the same time, small businesses get pay-as-you-go access to advanced multi-vendor software solutions that will improve their products.

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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

Proceedings of the 10th International Conference on PErvasive Technologies Related to Assistive Environments

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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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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Towards a Complex Interaction Scenario in Worker-cobot Reconfigurable Collaborative Manufacturing via Reactive Agent Ontology

2017

IC3K 2017. Proceedings of the 9th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management

International Conference on Knowledge Engineering and Ontology Development (KEOD) <9, 2017, Funchal, Madeira, Portugal>

Close Human-Robot Interaction (HRI) has been a great focus of research for the last decades. The outcomes of this focus is a new field in industrial robotics called collaborative robotics. A collaborative robot (cobot) is usually an industrial robot designed to operate safely in a shared work environment with the human worker. This in contrast to conventional Industrial Robots (IRs) which are operating in isolation from the worker workspace, the cobot is changing the concept of automation from fully automated operations to semiautonomous operations, where the decisions of the worker will influence the actions of the cobot and viceversa. Therefore, a communication and information control framework must exist to connect the worker and the cobot together to fulfil this semi-autonomous paradigm. This framework should be able to provide a method to represent the common knowledge which can support the collaborative manufacturing between the worker and the cobot. During this research we are proposing an ontology-based Holonic Control Architecture (HCA) as a proper solution to share and communicate the knowledge needed to achieve complex interaction scenarios between the worker and the cobot.

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Bardsley, Patrick; Barmak, Katayun; Eggeling, Eva; Epshteyn, Yekaterina; Kinderlehrer, David; Ta'asan, Shlomo

Towards a Gradient Flow for Microstructure

2017

Rendiconti Lincei - Matematica e Applicazioni

A central problem of microstructure is to develop technologies capable of producing an arrangement, or ordering, of a polycrystalline material, in terms of mesoscopic parameters, like geometry and crystallography, appropriate for a given application. Is there such an order in the first place? Our goal is to describe the emergence of the grain boundary character distribution (GBCD), a statistic that details texture evolution discovered recently, and to illustrate why it should be considered a material property. For the GBCD statistic, we have developed a theory that relies on mass transport and entropy. The focus of this paper is its identification as a gradient flow in the sense of De Giorgi, as illustrated by Ambrosio, Gigli, and Savare´. In this way, the empirical texture statistic is revealed as a solution of a Fokker-Planck type equation whose evolution is determined by weak topology kinetics and whose limit behavior is a Boltzmann distribution. The identification as a gradient flow by our method is tantamount to exhibiting the harvested statistic as the iterates in a JKO implicit scheme. This requires several new ideas. The development exposes the question of how to understand the circumstances under which a harvested empirical statistic is a property of the underlying process.

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Ulmer, Alex; Kohlhammer, Jörn; Shulman, Haya

Towards Enhancing the Visual Analysis of Interdomain Routing

2017

IVAPP 2017. Proceedings

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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Cibulski, Lena; Preim, Bernhard [Advisor]; May, Thorsten [Advisor]

Towards Visual Feature Selection for Multivariate Time Series Data

2017

Magdeburg, Univ., Master Thesis, 2017

Time series analysis and modeling are essential tools for the transfer of knowledge across time, also called forecasting. This often involves the task of identifying the least number of features that are most useful for building a model that accurately forecasts a target without suffering from dimensionality issues. This is challenging, because time series involve many different characteristics that need to be captured by a model. Traditional wrapper approaches are bound to the actual learning algorithm that builds the model, which requires computational effort and limits their range of application. Filter methods are independent of the future model, but mostly take the form of a black box algorithm, which does not allow analysts to monitor and interactively guide the feature selection. In this thesis, the filter concept for multivariate time series is advanced by making use of the human perception and interpretation abilities for independent evaluation of a feature subset's quality. To ensure independence, we derive a quality criterion from a general assumption about the relationship between input and output in a valid model. An overview visualization enables analysts to visually assess its validity and to steer the analysis towards regions of interest, where the feature subset's quality is not sufficient. Critical regions can be analyzed in detail using the surrounding system of linked views. Findings contribute to an interactive refinement of the feature subset, which might also include the analyst's expertise. We evaluate the proposed method by applying it to real-world sensor data and an artificial time-oriented data set. The analyst was able to quickly distinguish well-explained regions from critical parts of the feature space, for which the identification of an additional explanatory feature could be tackled straight-away. Due to visualization constraints, the approach can handle only two-dimensional feature subsets, which are taken as input to perform one feature selection iteration. Still, it might be an inspiring step in the direction of universal dimension reduction that involves the human strengths.

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

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

2017

2017 Proceedings of the 25th European Signal Processing Conference (EUSIPCO)

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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Landesberger, Tatiana von; Bremm, Sebastian; Wunderlich, Marcel

Typology of Uncertainty in Static Geolocated Graphs for Visualization

2017

IEEE Computer Graphics and Applications

Static geolocated graphs have nodes connected by edges that can have geographic location and associated attributes. This article proposes a typology of uncertainty in static geolocated graphs, which can affect the existence, location, attributes, or grouping of nodes and edges. The authors also summarize available techniques for visualizing such uncertainty.

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Wrasse, Kevin; Diener, Holger; Hayka, Haygazun; Stark, Rainer

Unified Information Access in Product Creation with an Integrated Control Desk

2017

The 4th International Conference on Manufacturing and Industrial Technologies 2017

International Conference on Manufacturing and Industrial Technologies (ICMIT) <4, 2017, Lisbon, Portugal>

Customers demand for individualized products leads to a large variety of different products in small series and single-unit production. A high flexibility pressure in product creation is one result of this trend. In order to counteract the pressure, the information steadily increasing by Industry4.0 must be made available at the workplace. Additionally, a better exchange of information between product development, production planning and production is necessary. The improvement of individual systems, like CAD, PDM, ERP and MES, can only achieve this to a limited extent. Since they mostly use systems from different manufacturers, the necessary deeper integration of information is only feasible for SMEs to a limited extend. The presented control desk helps to ensure a more flexible product creation as well as information exchange. It captures information from different IT systems in the production process and presents them integrated, task-oriented and oriented to the user's mental model, e.g. information of the production combined with the 3D model of product parts, or information about product development on the 3D model of the production. The solution is a digital 3D model of the manufacturing environment, which is enriched by billboards for a quick information overview and web service windows to access detailed MES and PDM information. By this, the level of abstraction can be reduced and reacts to changed requirements in the short term, making informed decisions. The interaction with the control stands utilizes the touch skills of mobile and fixed systems such as smartphones, tablets and multitouch tables.

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

2017

Computer Vision - ACCV 2016. Part V

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

CGI 2017. Proceedings of the Computer Graphics International Conference

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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Oksuz, Ilkay; Mukhopadhyay, Anirban; Dharmakumar, Rohan; Tsaftaris, Sotirios A.

Unsupervised Myocardial Segmentation for Cardiac BOLD

2017

IEEE Transactions on Medical Imaging

A fully automated 2-D+time myocardial segmentation framework is proposed for cardiac magnetic resonance (CMR) blood-oxygen-level-dependent (BOLD) data sets. Ischemia detection with CINE BOLD CMR relies on spatio-temporal patterns in myocardial intensity, but these patterns also trouble supervised segmentation methods, the de facto standard for myocardial segmentation in cine MRI. Segmentation errors severely undermine the accurate extraction of these patterns. In this paper, we build a joint motion and appearance method that relies on dictionary learning to find a suitable subspace.Our method is based on variational pre-processing and spatial regularization using Markov random fields, to further improve performance. The superiority of the proposed segmentation technique is demonstrated on a data set containing cardiac phase resolved BOLD MR and standard CINE MR image sequences acquired in baseline and is chemic condition across ten canine subjects. Our unsupervised approach outperforms even supervised state-of-the-art segmentation techniques by at least 10% when using Dice to measure accuracy on BOLD data and performs at par for standard CINE MR. Furthermore, a novel segmental analysis method attuned for BOLD time series is utilized to demonstrate the effectiveness of the proposed method in preserving key BOLD patterns.

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Wendland, Steve; Lukas, Uwe von

Unterwassertestfeld für maritime Robotik und Sensorik

2017

Hydrographische Nachrichten

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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Paredes, Hugo; Barroso, João; Morgado, Leonel; Pereira, Rogério; Leal, Ana; Carvalho, Fausto de; Ribeiro, Vitor; Braun, Andreas; Casati, Fabio; Gaillard, Romain

UPPERCARE: A Community Aware Environment for Post-surgical Musculoskeletal Recovery of Elderly Patients

2017

Proceedings of the 2017 IEEE 21st International Conference on Computer Supported Cooperative Work in Design (CSCWD)

International Conference on Computer Supported Cooperative Work in Design (CSCWD) <21, 2017, Wellington, New Zealand>

Disability from musculoskeletal diseases and comorbidities may lead to the worsening of social and economic well-being through a multitude of paths. Moreover since in European Union (EU) Member States it is projected that those aged 65 and over will become a much larger share (rising from 17% to 30% of the population), and those aged 80 and over (rising from 5% to 12%) will almost become as numerous as the young population in 2060, there is a great potential for Information and Communication Technologies (ICT) solutions for addressing the present and future living arrangements in older people. The UPPERCARE system is meant to affect positively both the intergenerational and partners care since it contributes to decrease usability barriers and promote collaborative environments for informal and self-care. UPPERCARE is a new approach for integrated care supported by ICT systems and services, focusing on post-operative rehabilitation of musculoskeletal pathologies, having as a case study the knee post-operative scenarios of prosthetic care. This paper presents the UPPERCARE system, that provides an integrated care solution, supported ICT, for empowering self-care and adherence to rehabilitation plans through natural interfaces, gamification and cross-modal paths for community care collaboration. The system addresses current barriers from technological, clinical, social and organisational perspectives in a multidisciplinary environment. Special attention is given to the patients' needs and behaviours entailing the participation of a wide care community, including clinical and non-clinical people, associations, institutions and authorities) through an user driven interaction within the system.

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Bernard, Felix; Engelke, Timo; Kuijper, Arjan

User Friendly Calibration for Tracking of Optical Stereo See-Through Head Worn Displays for Augmented Reality

2017

2017 International Conference on Cyberworlds

International Conference on Cyberworlds (CW) <2017, Chester, UK>

In recent time devices like Google Glass and Oculus Rift gained a lot of public attention. So the field of Virtual and Augmented Reality has become a more and more attractive field of study. Optical Stereo See-Through Head Worn Displays (OST-HWD or OST-HMD) can be used for Augmented Reality, but have to be calibrated. This means, that one has to find a configuration, that aligns the image shown on the displays with the environment, which is observed by the built-in camera. If this is not done, the augmented virtual image would not align with the real world. In this paper, the process of this calibration approach is divided into two stages, hardware and user calibration, but with less constraints for the positions of the cameras, which makes it easier to use. We aim at a more user friendly suite for the calibration of OST-HWD devices. Therefore both of the aforementioned stages are combined in a new quick step-by-step installation wizard, which is written in HTML and JavaScript to ensure easy usability. We apply a new minimization model in order to simplify and robustify the calculations of the virtual plane. In addition to that the required hardware components, including camera and calibration rig, were simplified. The implemented software has been evaluated for its results of the computed virtual plane, intrinsic data and eye positions of the user. Finally a user study was conducted to rate the usability of the calibration process.

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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

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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Piero, Nils; Schmitt, Michael

Virtual Commissioning of Camera-based Quality Assurance Systems for Mixed Model Assembly Lines

2017

Procedia Manufacturing

International Conference on Flexible Automation and Intelligent Manufacturing (FAIM) <27, 2017, Modena, Italy>

We propose a new computer vision based technique that does not use data collected from real images to teach a decision-making algorithm. It uses CAD-Models which is already available from the product planning phase to check all product variants on the assembly line for misplaced or wrong components. This solution can hence be used already in the ramp-up phase of new models in which problems are more frequent. Our method can also easily adapt to changes of production, where existing methods need to redo the whole teach-in process, we just need to set the new nominal position of the part in the reference coordinate system, which can even be done semi automatically upfront the changes are initiated in the assembly line.

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Wächter, Michael; Beljan, Mate; Fuhrmann, Simon; Moehrle, Nils; Kopf, Johannes; Goesele, Michael

Virtual Rephotography: Novel View Prediction Error for 3D Reconstruction

2017

ACM Transactions on Graphics

The ultimate goal of many image-based modeling systems is to render photorealistic novel views of a scene without visible artifacts. Existing evaluation metrics and benchmarks focus mainly on the geometric accuracy of the reconstructed model, which is, however, a poor predictor of visual accuracy. Furthermore, using only geometric accuracy by itself does not allow evaluating systems that either lack a geometric scene representation or utilize coarse proxy geometry. Examples include a light field and most image-based rendering systems. We propose a unified evaluation approach based on novel view prediction error that is able to analyze the visual quality of any method that can render novel views from input images. One key advantage of this approach is that it does not require ground truth geometry. This dramatically simplifies the creation of test datasets and benchmarks. It also allows us to evaluate the quality of an unknown scene during the acquisition and reconstruction process, which is useful for acquisition planning. We evaluate our approach on a range of methods, including standard geometry-plus-texture pipelines as well as image-based rendering techniques, compare it to existing geometry-based benchmarks, demonstrate its utility for a range of use cases, and present a new virtual rephotography-based benchmark for image-based modeling and rendering systems.

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Virtuelle Realität in der Medizin

2017

Medizintechnik

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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Aroudj, Samir; Seemann, Patrick; Langguth, Fabian; Guthe, Stefan; Goesele, Michael

Visibility-Consistent Thin Surface Reconstruction Using Multi-Scale Kernels

2017

ACM Transactions on Graphics

Conference on Computer and Exhibition on Computer Graphics and Interactive Techniques in Asia (SIGGRAPH ASIA) <10, 2017, Bangkok, Thailand>

One of the key properties of many surface reconstruction techniques is that they represent the volume in front of and behind the surface, e.g., using a variant of signed distance functions. This creates significant problems when reconstructing thin areas of an object since the backside interferes with the reconstruction of the front. We present a two-step technique that avoids this interference and thus imposes no constraints on object thickness. Our method first extracts an approximate surface crust and then iteratively refines the crust to yield the final surface mesh. To extract the crust, we use a novel observation-dependent kernel density estimation to robustly estimate the approximate surface location from the samples. Free space is similarly estimated from the samples' visibility information. In the following refinement, we determine the remaining error using a surface-based kernel interpolation that limits the samples' influence to nearby surface regions with similar orientation and iteratively move the surface towards its true location. We demonstrate our results on synthetic as well as real datasets reconstructed using multi-view stereo techniques or consumer depth sensors.

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Salahuddin, Ahmad Masood; Kuijper, Arjan [Advisor]; Siegmund, Dirk [Supervisor]

Vision Based Food Recognition

2017

Darmstadt, TU, Master Thesis, 2017

Food recognition has always been a complex task to achieve due to deformable nature of food items. A lot of different food items can look pretty much identical because of their same shape and colour and the wide rage of diversity they are present in. Some time it is even difficult for humans to distinguish between different food items based on their visual characteristics. Main goal of this thesis is to see if it is possible to provide a viable solution to canteen owner so that they can do price calculation of their food products and to analyze different techniques that could be used in food recognition for cashier systems. All this cost estimation should be done in a reasonable amount of time (One customer should not spend more than 5 to 10 secs waiting for cost evaluation of his/her food). Flow of system should also be simple so that every customer can adopt to it very easily. Objective is to provide a simple solution in which purchased items could be identified from an image. Customer would only be required to place tray under a camera and no further interaction from customer point of view would be required in cost evaluation. Enrolment of new components in system should also be easy and less time consuming. To achieve the end target, system would be relying on cutting edge Deep Learning(DL) techniques. As over the past few years (Especially after Alexnet Which came in 2012) DL has shown very promising results in the areas of image classification and image segmentation. DL has also been very helpful when it comes to finding similarities between different images or for Maximum Likely-hood Estimation. Readers of this thesis document will see how different DL techniques can be combined to achieve food classification task. This report will give a detailed analysis about how different techniques, which are used to solve other complex problems like face recognition or signature verification, can be modified to perform food recognition. To achieve optimum classification results I examined different Neural Network(NN) architectures and evaluated their results. Best performance was achieved by training a Convolutional Neural Network( CNN) based on Inception architecture against the Triplet Loss. This method achieved a HTER of 10.3%. It was further investigated that these results could be further enhanced with the application of appropriate supervised image segmentation techniques.

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Visual Access to Performance Indicators in the Mining Sector

2017

Eurographics / IEEE VGTC Conference on Visualization (EuroVis) - Short Papers

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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Shao, Lin; Silva, Nelson; Eggeling, Eva; Schreck, Tobias

Visual Exploration of Large Scatter Plot Matrices by Pattern Recommendation based on Eye Tracking

2017

ESIDA '17

ACM Workshop on Exploratory Search and Interactive Data Analytics <2017, Limassol, Cyprus>

The Scatter Plot Matrix (SPLOM) is a well-known technique for visual analysis of high-dimensional data. However, one problem of large SPLOMs is that typically not all views are potentially relevant to a given analysis task or user. The matrix itself may contain structured patterns across the dimensions, which could interfere with the investigation for unexplored views. We introduce a new concept and prototype implementation for an interactive recommender system supporting the exploration of large SPLOMs based on indirectly obtained user feedback from user eye tracking. Our system records the patterns that are currently under exploration based on gaze times, recommending areas of the SPLOM containing potentially new, unseen patterns for successive exploration. We use an image-based dissimilarity measure to recommend patterns that are visually dissimilar to previously seen ones, to guide the exploration in large SPLOMs. The dynamic exploration process is visualized by an analysis provenance heatmap, which captures the duration on explored and recommended SPLOM areas. We demonstrate our exploration process by a user experiment, showing the indirectly controlled recommender system achieves higher pattern recall as compared to fully interactive navigation using mouse operations.

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

2017

Visualization and Data Analysis 2017

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

IVAPP 2017. Proceedings

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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Ramalwan, Vinod Singh; Kuijper, Arjan [1. Gutachten]; Burkhardt, Dirk [2. Gutachten]

Visual Trend Analysis for Instant Analysis in Mobile Environments

2017

Darmstadt, TU, Master Thesis, 2017

Today's rapidly changing markets challenge enterprises to stay up and react early to latest trends, such as technologies and market players. In the past, big players like AOL, Yahoo suffered significant impact in their own businesses due to changes in the market. Hence, detection of trends is crucial to consider upcoming trends as soon as possible. In particular, small and medium enterprises need an easy and early trend detection system. However, such systems must be aligned with their daily business. Analytical observations create significant impact and often prove to be profitable to businesses. However, current solutions need a huge amount of effort to collect data and perform the analysis. To incorporate such a solution, it is essential to have a system that enables to quickly check an upcoming trend without heavy parameterization. More often, analytical observations prove to be especially beneficial in mobile environments, like traveling, where they save time by performing analysis instantly e.g. on a mobile-phone or a tablet. In the past decade, mobile device development has changed the technology market symbolically. However, still today, desktop devices are preferred over mobile devices for visual analysis where device memory, display size, device speed etc. are the major factors contributing to this choice. In this work, I propose a concept aimed at analyzing visual trends in mobile environments which would assist decision makers and business leaders to perform analysis on demand. The proposed concept not only considers the limitations of mobile devices but also utilizes their special features like gesture interactions. This concept integrates a prospect known as a scenario. Each scenario integrates visual metaphors which altogether complete the profile of a subject. A digital library search about research publications was used to choose the subjects in this case. For e.g. checking interesting topics or analyzing topic leaders of certain research area to estimate a technological trend in terms of their relevance and impact. Within the scope of this work, Human-Computer Interaction (HCI) was researched in the context of mobile devices and the supplementary features mobile devices provide in contrast to computers. The already existing techniques and solutions for visual trend analysis were evaluated. A proof-of-concept with a web application for mobile devices was implemented. Finally, the developed mobile web application was evaluated against an existing desktop web application based on same data. This study reveals that the new mobile solution has a significant advantage over the existing desktop solution, and it was preferred by the users. It is concluded that the design, intuitiveness, scenario-based concept of the mobile solution and other complementary features like interactions make it more concrete and goal-oriented.

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Sessler, David; Kuijper, Arjan [1. Gutachten]; Bernard, Jürgen [2. Gutachten]

Visual-Interactive Learning of Time Series Similarity

2017

Darmstadt, TU, Master Thesis, 2017

Similarity is important for the applicability of a series of data analysis tasks. Pattern recognition, clustering and nearest neighbor search require a meaningful similarity function for their functionality. In this work, we consider a similarity function to be meaningful, if it reflects the similarity notion in the minds of the users. Therefore, the design of a similarity function has to incorporate and reflect user's preferences. In this work we focus on the similarity for time-oriented data. The definition of similarity functions for this data type requires a cascade of routines, including preprocessing steps, descriptors, normalization steps, and distance measures. Referring to this cascade, manually choosing appropriate routines matching the user's expectations of time series similarity is a tedious process. We present a visual-interactive approach that identifies meaningful similarity functions for time-oriented data automatically. The core principle is to learn from user-defined labels about the similarity of pairs of time series. Automatic choice of fitting routines allows to match the similarity notion of the users at run time. We implement a labeling interface for pairwise time series, including active learning support to enhance the learning process. Different views allow the analysis of the learning process of similarity for time series data. A list-based ranking interface provides detailed information on the best performing similarity functions. Filtering interfaces allow for detailed analysis of the applicability of routines included in the similarity functions. Furthermore, they provide drill-down functionality that can be used to experiment with different sets of similarity functions, in order to increase the robustness of the prediction. Nearest neighbor search closes the feedback loop and enables the users to validate, if the defined similarity function complies with their notion of similarity. In addition, we demonstrate the applicability of the approach in case studies based on different pre-defined notions of similarity used for labeling. Finally, we evaluate our approach to determine which factors influence the prediction accuracy. In conclusion, our approach extends the classical user-centered and iterative design process to an online learning process that defines similarity functions based on user feedback. We report on an increase in efficiency from a tedious design process for similarity functions, down to a process that only takes minutes of expert time.

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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

Visualization and Data Analysis 2017

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

IVAPP 2017. Proceedings

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

Go-3D 2017: Mit 3D Richtung Maritim 4.0

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 [1. Gutachten]; May, Thorsten [2. Gutachten]

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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Wunderlich, Marcel; Ballweg, Kathrin; Fuchs, Georg; Landesberger, Tatiana von

Visualization of Delay Uncertainty and its Impact on Train Trip Planning: A Design Study

2017

Computer Graphics Forum

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

Uncertainty about possible train delays has an impact on train trips, as the exact arrival time is unknown during trip planning. Delays can lead to missing a connecting train at the transfer station, or to coming too late to an appointment at the destination. Facing this uncertainty, the traveler may wish to use an earlier train or a different connection arriving well before the appointment. Currently, train trip planning is based on scheduled times of connections between two stations. Information about approximate delays is only available shortly before train departure. Although several visualization approaches can show temporal uncertainty, we are not aware of any visual design specifically supporting trip planning, which can show delay uncertainty and its impact on the connections. We propose and evaluate a visual design which extends train trip planning with delay uncertainty. It shows the scheduled train connections together with their expected train delays as well as their impacts on both the arrival time, and the potential of missing a transfer. The visualization also includes information about alternative connections in case of these critical transfers. In this way the user is able to judge which train connection is suitable for a trip. We conducted a user study with 76 participants to evaluate our design. We compared it to two alternative presentations that are prominent in Germany. The study showed that our design performs comparably well for tasks concerning train schedules. The additional uncertainty display as well as the visualization of alternative connections was appreciated and well understood. The participants were able to estimate when they would likely arrive at their destination despite possible train delays while they were unable to estimate this with existing presentations. The users would prefer to use the new design for their trip planning.

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Volumetric Subdivision for Consistent Implicit Mesh Generation

2017

Computers & Graphics

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, while automatic checks and modifications of inner control points ensure consistency during the design process. 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. We measured and evaluated the timings for generating and applying the matrices for different subdivision levels. Additionally, we computed several characteristic factors for mesh quality and mesh consistency. For comparison, we analyzed 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, as all the required information is already available.

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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

Web-basierte Anwendungen Virtueller Techniken: Das ARVIDA-Projekt - Dienste-basierte Software-Architektur und Anwendungsszenarien für die Industrie

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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Helali, Ahmed Mahmoud Abdelbadie; Urban, Bodo [Supervisor]; Sadik, Ahmed R. [Supervisor]

Worker-Robot Collaboration in Reconfigurable Manufacturing Scenario with Task Scheduling and Gesture Recognition

2017

Rostock, Univ., Bachelor Thesis, 2017

In the global economy of today, manufacturing enterprises face a new challenge. Product customization is needed to be able to match current customer needs and market demands. Reconfigurable Manufacturing Systems (RMS) offers a solution to this new emerging trend. RMS tries to achieve product customization in its products, but at the same time be able to provide reasonable production rates. One of the new emerging technologies that can help RMS achieve its goals is collaborative robotics. However, many challenges face collaborative robotics for RMS. Challenges mainly exist in the communication and control system, task recognition and scheduling. In this thesis, the author tries to provide a system and a workcell environment that handles these challenges in a basic and simple manner. This includes using technologies such as Holonic Control Architecture (HCA), Multi-Agent System (MAS) and gesture recognition. The system was able to address the following challenges; product customization, system scalability, system flexibility and communication between two different entities with different control paradigms. It is hoped that this thesis will provide a core and a simple system that can be used in the future of RMS.

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X3ogre: Connecting X3D to a State of the Art Rendering Engine

2017

Proceedings Web3D 2017

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

We connect X3D to the state of the art OGRE renderer using our prototypical x3ogre implementation. At this we perform a comparison of both on a conceptual level, highlighting similarities and differences. Our implementation allows swapping X3D concepts for OGRE concepts and vice versa. We take advantage of this to analyse current shortcomings in X3D and propose X3D extensions to overcome those.