004 Datenverarbeitung; Informatik
Refine
Document Type
- Report (16)
- Doctoral Thesis (15)
- Article (7)
- Preprint (3)
- Part of a Book (2)
- Master's Thesis (2)
- Conference Proceeding (1)
Institute
- Junior-Professur Augmented Reality (16)
- Professur Computergestütztes kooperatives Arbeiten (9)
- Professur Content Management und Webtechnologien (5)
- F. A. Finger-Institut für Baustoffkunde (FIB) (2)
- Professur Informatik in der Architektur (2)
- Professur Medieninformatik (2)
- Professur Systeme der Virtuellen Realität (2)
- In Zusammenarbeit mit der Bauhaus-Universität Weimar (1)
- Medienkunst/Mediengestaltung (1)
- Professur Bauphysik (1)
Keywords
Multi-Frame Rate Rendering
(2008)
Multi-frame rate rendering is a parallel rendering technique that renders interactive parts of a scene on one graphics card while the rest of the scene is rendered asynchronously on a second graphics card. The resulting color and depth images of both render processes are composited, by optical superposition or digital composition, and displayed. The results of a user study confirm that multi-frame rate rendering can significantly improve the interaction performance. Multi-frame rate rendering is naturally implemented on a graphics cluster. With the recent availability of multiple graphics cards in standalone systems the method can also be implemented on a single computer system where memory bandwidth is much higher compared to off-the-shelf networking technology. This decreases overall latency and further improves interactivity. Multi-frame rate rendering was also investigated on a single graphics processor by interleaving the rendering streams for the interactive elements and the rest of the scene. This approach enables the use of multi-frame rate rendering on low-end graphics systems such as laptops, mobile phones, and PDAs. Advanced multi-frame rate rendering techniques reduce the limitations of the basic approach. The interactive manipulation of light sources and their parameters affects the entire scene. A multi-GPU deferred shading method is presented that splits the rendering task into a rasterization and lighting pass and assigns the passes to the appropriate image generators such that light manipulations at high frame rates become possible. A parallel volume rendering technique allows the manipulation of objects inside a translucent volume at high frame rates. This approach is useful for example in medical applications, where small probes need to be positioned inside a computed-tomography image. Due to the asynchronous nature of multi-frame rate rendering artifacts may occur during migration of objects from the slow to the fast graphics card, and vice versa. Proper state management allows to almost completely avoid these artifacts. Multi-frame rate rendering significantly improves the interactive manipulation of objects and lighting effects. This leads to a considerable increase of the size for 3D scenes that can be manipulated compared to conventional methods.
We present a novel multi-step technique for imperceptible geometry and radiometry calibration of projector-camera systems. Our approach can be used to display geometry and color corrected images on non-optimized surfaces at interactive rates while simultaneously performing a series of invisible structured light projections during runtime. It supports disjoint projector-camera configurations, fast and progressive improvements, as well as real-time correction rates of arbitrary graphical content. The calibration is automatically triggered when mis-registrations between camera, projector and surface are detected.
Among all imaging techniques that have been invented throughout the last decades, computer graphics is one of the most successful tools today. Many areas in science, entertainment, education, and engineering would be unimaginable without the aid of 2D or 3D computer graphics. The reason for this success story might be its interactivity, which is an important property that is still not provided efficiently by competing technologies – such as holography. While optical holography and digital holography are limited to presenting a non-interactive content, electroholography or computer generated holograms (CGH) facilitate the computer-based generation and display of holograms at interactive rates [2,3,29,30]. Holographic fringes can be computed by either rendering multiple perspective images, then combining them into a stereogram [4], or simulating the optical interference and calculating the interference pattern [5]. Once computed, such a system dynamically visualizes the fringes with a holographic display. Since creating an electrohologram requires processing, transmitting, and storing a massive amount of data, today’s computer technology still sets the limits for electroholography. To overcome some of these performance issues, advanced reduction and compression methods have been developed that create truly interactive electroholograms. Unfortunately, most of these holograms are relatively small, low resolution, and cover only a small color spectrum. However, recent advances in consumer graphics hardware may reveal potential acceleration possibilities that can overcome these limitations [6]. In parallel to the development of computer graphics and despite their non-interactivity, optical and digital holography have created new fields, including interferometry, copy protection, data storage, holographic optical elements, and display holograms. Especially display holography has conquered several application domains. Museum exhibits often use optical holograms because they can present 3D objects with almost no loss in visual quality. In contrast to most stereoscopic or autostereoscopic graphics displays, holographic images can provide all depth cues—perspective, binocular disparity, motion parallax, convergence, and accommodation—and theoretically can be viewed simultaneously from an unlimited number of positions. Displaying artifacts virtually removes the need to build physical replicas of the original objects. In addition, optical holograms can be used to make engineering, medical, dental, archaeological, and other recordings—for teaching, training, experimentation and documentation. Archaeologists, for example, use optical holograms to archive and investigate ancient artifacts [7,8]. Scientists can use hologram copies to perform their research without having access to the original artifacts or settling for inaccurate replicas. Optical holograms can store a massive amount of information on a thin holographic emulsion. This technology can record and reconstruct a 3D scene with almost no loss in quality. Natural color holographic silver halide emulsion with grain sizes of 8nm is today’s state-of-the-art [14]. Today, computer graphics and raster displays offer a megapixel resolution and the interactive rendering of megabytes of data. Optical holograms, however, provide a terapixel resolution and are able to present an information content in the range of terabytes in real-time. Both are dimensions that will not be reached by computer graphics and conventional displays within the next years – even if Moore’s law proves to hold in future. Obviously, one has to make a decision between interactivity and quality when choosing a display technology for a particular application. While some applications require high visual realism and real-time presentation (that cannot be provided by computer graphics), others depend on user interaction (which is not possible with optical and digital holograms). Consequently, holography and computer graphics are being used as tools to solve individual research, engineering, and presentation problems within several domains. Up until today, however, these tools have been applied separately. The intention of the project which is summarized in this chapter is to combine both technologies to create a powerful tool for science, industry and education. This has been referred to as HoloGraphics. Several possibilities have been investigated that allow merging computer generated graphics and holograms [1]. The goal is to combine the advantages of conventional holograms (i.e. extremely high visual quality and realism, support for all depth queues and for multiple observers at no computational cost, space efficiency, etc.) with the advantages of today’s computer graphics capabilities (i.e. interactivity, real-time rendering, simulation and animation, stereoscopic and autostereoscopic presentation, etc.). The results of these investigations are presented in this chapter.
With the growing importance of the World Wide Web, the major challenges our society faces are also increasingly affecting the digital areas of our lives. Some of the associated problems can be addressed by computer science, and some of these specifically by data-driven research. To do so, however, requires to solve open issues related to archive quality and the large volume and variety of the data contained.
This dissertation contributes data, algorithms, and concepts towards leveraging the big data and temporal provenance capabilities of web archives to tackle societal challenges. We selected three such challenges that highlight the central issues of archive quality, data volume, and data variety, respectively:
(1) For the preservation of digital culture, this thesis investigates and improves the automatic quality assurance of the web page archiving process, as well as the further processing of the resulting archive data for automatic analysis.
(2) For the critical assessment of information, this thesis examines large datasets of Wikipedia and news articles and presents new methods for automatically determining quality and bias.
(3) For digital security and privacy, this thesis exploits the variety of content on the web to quantify the security of mnemonic passwords and analyzes the privacy-aware re-finding of the various seen content through private web archives.
Multi-user virtual reality systems enable collocated as well as distributed users to perform collaborative activities in immersive virtual environments. A common activity in this context is to move from one location to the next as a group to explore the environment together. The simplest solution to realize these multi-user navigation processes is to provide each participant with a technique for individual navigation. However, this approach entails some potentially undesirable consequences such as the execution of a similar navigation sequence by each participant, a regular need for coordination within the group, and, related to this, the risk of losing each other during the navigation process.
To overcome these issues, this thesis performs research on group navigation techniques that move group members together through a virtual environment. The presented work was guided by four overarching research questions that address the quality requirements for group navigation techniques, the differences between collocated and distributed settings, the scalability of group navigation, and the suitability of individual and group navigation for various scenarios. This thesis approaches these questions by introducing a general conceptual framework as well as the specification of central requirements for the design of group navigation techniques. The design, implementation, and evaluation of corresponding group navigation techniques demonstrate the applicability of the proposed framework.
As a first step, this thesis presents ideas for the extension of the short-range teleportation metaphor, also termed jumping, for multiple users. It derives general quality requirements for the comprehensibility of the group jumping process and introduces a corresponding technique for two collocated users. The results of two user studies indicate that sickness symptoms are not affected by user roles during group jumping and confirm improved planning accuracy for the navigator, increased spatial awareness for the passenger, and reduced cognitive load for both user roles.
Next, this thesis explores the design space of group navigation techniques in distributed virtual environments. It presents a conceptual framework to systematize the design decisions for group navigation techniques based on Tuckman's model of small-group development and introduces the idea of virtual formation adjustments as part of the navigation process. A quantitative user study demonstrates that the corresponding extension of Multi-Ray Jumping for distributed dyads leads to more efficient travel sequences and reduced workload. The results of a qualitative expert review confirm these findings and provide further insights regarding the complementarity of individual and group navigation in distributed virtual environments.
Then, this thesis investigates the navigation of larger groups of distributed users in the context of guided museum tours and establishes three central requirements for (scalable) group navigation techniques. These should foster the awareness of ongoing navigation activities as well as facilitate the predictability of their consequences for all group members (Comprehensibility), assist the group with avoiding collisions in the virtual environment (Obstacle Avoidance), and support placing the group in a meaningful spatial formation for the joint observation and discussion of objects (View Optimization). The work suggests a new technique to address these requirements and reports on its evaluation in an initial usability study with groups of five to ten (partially simulated) users. The results indicate easy learnability for navigators and high comprehensibility for passengers. Moreover, they also provide valuable insights for the development of group navigation techniques for even larger groups.
Finally, this thesis embeds the previous contributions in a comprehensive literature overview and emphasizes the need to study larger, more heterogeneous, and more diverse group compositions including the related social factors that affect group dynamics.
In summary, the four major research contributions of this thesis are as follows:
- the framing of group navigation as a specific instance of Tuckman's model of small-group development
- the derivation of central requirements for effective group navigation techniques beyond common quality factors known from single-user navigation
- the introduction of virtual formation adjustments during group navigation and their integration into concrete group navigation techniques
- evidence that appropriate pre-travel information and virtual formation adjustments lead to more efficient travel sequences for groups and lower workloads for both navigators and passengers
Overall, the research of this thesis confirms that group navigation techniques are a valuable addition to the portfolio of interaction techniques in multi-user virtual reality systems. The conceptual framework, the derived quality requirements, and the development of novel group navigation techniques provide effective guidance for application developers and inform future research in this area.
Im Rahmen der Arbeit wird untersucht, welche Awarenessinformationen in kooperativen Situation benötigt werden. Herangezogen wird dazu das Denver Modell von Salvador et al., das fünf Dimensionen bereit stellt, anhand derer jedwede kooperative Situation klassifiziert werden kann: Abhängigkeit, Zeit, Gruppengröße, Ort und Timing. Bei der untersuchten Situation handelt es sich um eine eng gekoppelte, synchrone, örtlich verteilte geplante Kooperationen in einer Kleingruppe. Als konkrete Ausprägung der so bezeichneten Modellinstanz wird das Chat-basierte Rollenspiel betrachtet. In der Arbeit wird untersucht, welche Awarenessinformationen in einer so charakterisierten Situation benötigt werden und wie diese Awarenessinformationen benutzerfreundlich dargestellt werden können, so dass sie den Benutzer dabei unterstützen, sein kooperatives Ziel bzw. seine Teilziele zu erreichen. Dazu wurde eine Analyse des situativen Bedarfs durchgeführt und tragende Awarenessinformationssäulen identifiziert. Um zu Richtlinien zur Darstellung dieser benötigten Awarenessinformationen zu gelangen, wurden Annahmen aufgestellt, zur Überprüfung eine Studie konzipiert und mit drei Designvarianten durchgeführt. Aus der Datenanalyse wurden Schlussfolgerungen gezogen. Für den erstellten Katalog mit Gestaltungsrichtlinien wurden neben diesen Schlussfolgerungen auch Normen und andere Empirie (Vorerfahrung, Literatur) berücksichtigt. Die eingesetzte Evaluationsform hat sich in der Studie bewährt und sie kann für zukünftige Studien verwendet werden. Auch die Anpassung klassischer Usability-Kriterien für die Präsentation von Awarenessinformationen hat sich bewährt. Durch die Analyse des spezifischen Bedarfs in einer kooperativen Situation wird gewährleistet, dass die Benutzer die Unterstützung erhalten, die erforderlich ist, um die Aufgabe effektiv und effizient bearbeiten zu können, ohne dabei mit unnötigen Informationen überlastet zu werden. Durch Bereitstellung empirisch belegter und theoretisch fundierter Gestaltungsrichtlinien schafft diese Arbeit eine Basis für die zukünftige Entwicklung von Groupwareanwendungen, insbesondere solcher, die Werkzeuge für die Computer-vermittelte, synchrone, eng gekoppelte, geplante Kooperationen in Kleingruppen bereitstellen. Die Arbeit liefert wichtige Erkenntnisse, wie Awarenessinformationen dargestellt werden sollen, d.h. in welcher Platzierung bzw. Gruppierung und in welcher Form, so dass der Benutzer alle wesentlichen Awarenessinformationen schnell entdecken und interpretieren kann, ohne dabei überfordert oder von der Primäraufgabe abgelenkt zu werden.
CAMShift is a well-established and fundamental algorithm for kernel-based visual object tracking. While it performs well with objects that have a simple and constant appearance, it is not robust in more complex cases. As it solely relies on back projected probabilities it can fail in cases when the object's appearance changes (e.g. due to object or camera movement, or due to lighting changes), when similarly colored objects have to be re-detected or when they cross their trajectories. We propose extensions to CAMShift that address and resolve all of these problems. They allow the accumulation of multiple histograms to model more complex object appearance and the continuous monitoring of object identi- ties to handle ambiguous cases of partial or full occlusion. Most steps of our method are carried out on the GPU for achieving real-time tracking of multiple targets simultaneously. We explain an ecient GPU implementations of histogram generation, probability back projection, im- age moments computations, and histogram intersection. All of these techniques make full use of a GPU's high parallelization.
Die heute erhältlichen Web-Content Management-Systeme (WCMS) verfügen über ein umfangreiches und breit gefächertes Angebot an Funktionen, die weit über die, zur Redaktion und zum Management von Internetpräsentationen, not-wendigen Grundanforderungen hinausgehen. Das macht diese Systeme in ih-ren Einsatz sehr flexibel und deckt vielfältige Anforderungen der Endanwender ab. Andererseits steigt durch die dadurch bedingte Komplexität der Arbeitsauf-wand erheblich und die Bedien- und Benutzerfreundlichkeit sinkt. Gerade für kleinere Internetpräsentationen, die ohne aufwendige Interaktionsmöglichkeiten aber auf häufig wechselndem Informationsangeboten aufwarten, wäre dies in seiner Grundfunktionalität reduziertes System vorteilhaft. Ein solches reduziertes Web-Content Management-System soll während der Diplomarbeit entworfen und beispielhaft implementiert werden. Als Ausgangs- und Orientierungspunkt soll hierzu die Internetpräsentation der Professur Informations- und Wissensverarbeitung dienen. Zur softwaretechnischen Umsetzung sind PHP und MySQL in Verbindung mit regulären HTML und CSS zu be-nutzen. Für das weitere Vorgehen müssen zunächst die Struktur und der Aufbau der Internetpräsentation der Professur analysiert, strukturiert und formalisiert werden. Anschließend sind die am häufigsten professionell genutzten Webcontent-Managementsysteme (TYPO3 und weitere siehe www.opensourcecms.com) hinsichtlich der durch sie angebotenen Grundfunktionalitäten und der verwen-deten Templates und Vorlagen zu untersuchen. Die aus dieser Analyse resultierenden Ergebnisse sind Ausgangspunkt für die Anforderungsdefinition des zu erstellenden Mini-WCMS. Anschließend ist eine prototypische Implementierung des theoretisch entstan-denen Systems, zugeschnitten auf die speziellen Bedürfnisse der Professur, vorzunehmen und hinsichtlich seiner Eignung zu diskutieren.
Die zu beobachtenden kürzeren Produktlebenszyklen und eine schnellere Marktdurchdringung von Produkttechnologien erfordern adaptive und leistungsfähige Produktionsanlagen. Die Adaptivität ermöglicht eine Anpassung der Produktionsanlage an neue Produkte, und die Leistungsfähigkeit der Anlage stellt sicher, dass ausreichend Produkte in kurzer Zeit und zu geringen Kosten hergestellt werden können. Durch eine Modularisierung der Produktionsanlage kann die Adaptivität erreicht werden. Jedoch erfordert heutzutage jede Adaption manuellen Aufwand, z.B. zur Anpassung von proprietären Signalen oder zur Anpassung übergeordneter Funktionen. Dadurch sinkt die Leistungsfähigkeit der Anlage.
Das Ziel dieser Arbeit ist es, die Interoperabilität in Bezug auf die Informationsverwendung in modularen Produktionsanlagen zu gewährleisten. Dazu werden Informationen durch semantische Modelle beschrieben. Damit wird ein einheitlicher Informationszugriff ermöglicht, und übergeordnete Funktionen erhalten Zugriff auf alle Informationen der Produktionsmodule, unabhängig von dem Typ, dem Hersteller und dem Alter des Moduls. Dadurch entfällt der manuelle Aufwand bei Anpassungen des modularen Produktionssystems, wodurch die Leistungsfähigkeit der Anlage gesteigert und Stillstandszeiten reduziert werden.
Nach dem Ermitteln der Anforderungen an einen Modellierungsformalismus wurden potentielle Formalismen mit den Anforderungen abgeglichen. OWL DL stellte sich als geeigneter Formalismus heraus und wurde für die Erstellung des semantischen Modells in dieser Arbeit verwendet. Es wurde exemplarisch ein semantisches Modell für die drei Anwendungsfälle Interaktion, Orchestrierung und Diagnose erstellt. Durch einen Vergleich der Modellierungselemente von unterschiedlichen Anwendungsfällen wurde die Allgemeingültigkeit des Modells bewertet. Dabei wurde gezeigt, dass die Erreichung eines allgemeinen Modells für technische Anwendungsfälle möglich ist und lediglich einige Hundert Begriffe benötigt.
Zur Evaluierung der erstellten Modelle wurde ein wandlungsfähiges Produktionssystem der SmartFactoryOWL verwendet, an dem die Anwendungsfälle umgesetzt wurden. Dazu wurde eine Laufzeitumgebung erstellt, die die semantischen Modelle der einzelnen Module zu einem Gesamtmodell vereint, Daten aus der Anlage in das Modell überträgt und eine Schnittstelle für die Services bereitstellt. Die Services realisieren übergeordnete Funktionen und verwenden die Informationen des semantischen Modells. In allen drei Anwendungsfällen wurden die semantischen Modelle korrekt zusammengefügt und mit den darin enthaltenen Informationen konnte die Aufgabe des jeweiligen Anwendungsfalles ohne zusätzlichen manuellen Aufwand gelöst werden.
Die Arbeit beschäftigt sich mit der komplexen Aufgabe Stadtstrukturen mit einem Simulationsmodell im Rechner erzeugen zu können. Dafür wird ein Vierebenenmodell als Untermodellebene eingeführt, um mit allgemeinen Informationen, Parzellierung, Gebäuden und Optimierung der Struktur arbeiten zu können.
This thesis focuses on the cryptanalysis and the design of block ciphers and hash func- tions. The thesis starts with an overview of methods for cryptanalysis of block ciphers which are based on differential cryptanalysis. We explain these concepts and also sev- eral combinations of these attacks. We propose new attacks on reduced versions of ARIA and AES. Furthermore, we analyze the strength of the internal block ciphers of hash functions. We propose the first attacks that break the internal block ciphers of Tiger, HAS-160, and a reduced round version of SHACAL-2. The last part of the thesis is concerned with the analysis and the design of cryptographic hash functions. We adopt a block cipher attack called slide attack into the scenario of hash function cryptanalysis. We then use this new method to attack different variants of GRINDAHL and RADIOGATUN. Finally, we propose a new hash function called TWISTER which was designed and pro- posed for the SHA-3 competition. TWISTER was accepted for round one of this com- petition. Our approach follows a new strategy to design a cryptographic hash function. We also describe several attacks on TWISTER and discuss the security issues concern- ing these attack on TWISTER.
Digital storytelling of remote social interaction, where the situation of a remote group distributed over two locations is captured and a story is generated for later retrieval, can provide valuable insight into the structure and processes in a group. Yet, capturing these situations is a challenge—both from a technical perspective, and from a social perspective. In this paper we present CoLocScribe: a concept and prototype of an advanced media space featuring ubiquitous computing technology for capturing remote social interaction as well as a study of its use providing valuable feedback for the captured persons as well as input for the authors.
Early sensor-based infrastructures were often developed by experts with a thorough knowledge of base technology for sensing information, for processing the captured data, and for adapting the system’s behaviour accordingly. In this paper we argue that also end-users should be able to configure Ubiquitous Computing environments. We introduce the CollaborationBus application: a graphical editor that provides abstractions from base technology and thereby allows multifarious users to configure Ubiquitous Computing environments. By composing pipelines users can easily specify the information flows from selected sensors via optional filters for processing the sensor data to actuators changing the system behaviour according to the users’ wishes. Users can compose pipelines for both home and work environments. An integrated sharing mechanism allows them to share their own compositions, and to reuse and build upon others’ compositions. Real-time visualisations help them understand how the information flows through their pipelines. In this paper we present the concept, implementation, and early user feedback of the CollaborationBus application.
Capturing the interaction of users in a room based on real-world and electronic sensors provides valuable input for their interactive stories. However, in such complex scenarios there is a gap between the huge amount of rather fine-grained data that is captured and the story summarising and representing the most significant aspects of the interaction. In this paper we present the CollaborationBus Aqua editor that provides an easy to use graphical editor for capturing, authoring, and sharing stories based on mixed-reality scenarios.
Virtual reality systems offer substantial potential in supporting decision processes based purely on computer-based representations and simulations. The automotive industry is a prime application domain for such technology, since almost all product parts are available as three-dimensional models. The consideration of ergonomic aspects during assembly tasks, the evaluation of humanmachine interfaces in the car interior, design decision meetings as well as customer presentations serve as but a few examples, wherein the benefit of virtual reality technology is obvious. All these tasks require the involvement of a group of people with different expertises. However, current stereoscopic display systems only provide correct 3D-images for a single user, while other users see a more or less distorted virtual model. This is a major reason why these systems still face limited acceptance in the automotive industry. They need to be operated by experts, who have an advanced understanding of the particular interaction techniques and are aware of the limitations and shortcomings of virtual reality technology. The central idea of this thesis is to investigate the utility of stereoscopic multi-user systems for various stages of the car development process. Such systems provide multiple users with individual and perspectively correct stereoscopic images, which are key features and serve as the premise for the appropriate support of collaborative group processes. The focus of the research is on questions related to various aspects of collaboration in multi-viewer systems such as verbal communication, deictic reference, embodiments and collaborative interaction techniques. The results of this endeavor provide scientific evidence that multi-viewer systems improve the usability of VR-applications for various automotive scenarios, wherein co-located group discussions are necessary. The thesis identifies and discusses the requirements for these scenarios as well as the limitations of applying multi-viewer technology in this context. A particularly important gesture in real-world group discussions is referencing an object by pointing with the hand and the accuracy which can be expected in VR is made evident. A novel two-user seating buck is introduced for the evaluation of ergonomics in a car interior and the requirements on avatar representations for users sitting in a car are identified. Collaborative assembly tasks require high precision. The novel concept of a two-user prop significantly increases the quality of such a simulation in a virtual environment and allows ergonomists to study the strain on workers during an assembly sequence. These findings contribute toward an increased acceptance of VR-technology for collaborative development meetings in the automotive industry and other domains.
Coded Aperture Projection
(2008)
In computer vision, optical defocus is often described as convolution with a filter kernel that corresponds to an image of the aperture being used by the imaging device. The degree of defocus correlates to the scale of the kernel. Convolving an image with the inverse aperture kernel will digitally sharpen the image and consequently compensate optical defocus. This is referred to as deconvolution or inverse filtering. In frequency domain, the reciprocal of the filter kernel is its inverse, and deconvolution reduces to a division. Low magnitudes in the Fourier transform of the aperture image, however, lead to intensity values in spatial domain that exceed the displayable range. Therefore, the corresponding frequencies are not considered, which then results in visible ringing artifacts in the final projection. This is the main limitation of previous approaches, since in frequency domain the Gaussian PSF of spherical apertures does contain a large fraction of low Fourier magnitudes. Applying only small kernel scales will reduce the number of low Fourier magnitudes (and consequently the ringing artifacts) -- but will also lead only to minor focus improvements. To overcome this problem, we apply a coded aperture whose Fourier transform has less low magnitudes initially. Consequently, more frequencies are retained and more image details are reconstructed.
In ubiquitous environments an increasing number of sensors capture information on users and at the same time an increasing number of actuators are available to present information to users. This vast capturing of information potentially enables the system to adapt to the users. At the same time the system might violate the users' privacy by capturing information that the users do not want to share, and the system might disrupt the users by being too obtrusive in its adaptation or information supply. In this paper we present CoDaMine - a novel approach for providing users with system - generated feedback and control in ubiquitous environments giving them the freedom they need while reducing their effort. Basically, CoDaMine captures and analyses the users' online communication to learn about their social relationships in order to provide them with recommendations for inter-personal privacy and trust management.
The effective and efficient cooperation in communities and groups requires that the members of the community or group have adequate information about each other and the environment. In this paper, we outline the basic challenges of managing awareness information. We analyse the management of awareness information in face-to-face situations, and discuss challenges and requirements for the support of awareness management in distributed settings. Finally, after taking a look at related work, we present a simple, yet powerful framework for awareness management based on constraint pattern named COBRA.
Visually impaired is a common problem for human life in the world wide. The projector-based AR technique has ability to change appearance of real object, and it can help to improve visibility for visually impaired. We propose a new framework for the appearance enhancement with the projector camera system that employed model predictive controller. This framework enables arbitrary image processing such as photo-retouch software in the real world and it helps to improve visibility for visually impaired. In this article, we show the appearance enhancement result of Peli's method and Wolffshon's method for the low vision, Jefferson's method for color vision deficiencies. Through experiment results, the potential of our method to enhance the appearance for visually impaired was confirmed as same as appearance enhancement for the digital image and television viewing.
Die technische Entwicklung, insbesondere auf dem Gebiet der Digitaltechnik eröffnet heute neue und sehr weitreichende Möglichkeiten für die Automatisierung in Zweck- und Wohnbauten. Die zur Verfügung stehenden technischen Komponenten (intelligente Sensoren und Aktoren sowie ein hausinternes Netz für die Datenübertragung -Feldbus-) unterscheiden sich für diese Einsatzfälle kaum. Die Zielstellungen sind jedoch gänzlich andere. Intelligenz im Wohnbau bedeutet vor allem intelligente Alltagsbewältigung (z.B. Zeiteinsparung), Komfort und Wohlbefinden. Daß im Heimbereich nichtfunktionale Faktoren (Human Interface, Ästhetik, Preis, Attraktivität) eine große Rolle spielen, ist in das Problembewußtsein der Gerätehersteller und Käufer getreten. Im Bereich der Heimautomatisierung werden zunehmend moderne, die Möglichkeiten der konventioellen Steuerungs- und Regelungstechnik ergänzende Technologien wie Fuzzy- Steuerungen zur Optimierung der internen Arbeitsweise von Geräten eingesetzt. Die informatorische Vernetzung im Wohnbau unterstützt darüberhinaus wichtige Anliegen des Gebäudemanagements (energetische, ergonomische und ökologische Betrachtungen der Gebäudenutzung unter wirtschaftlichen Gesichtspunkten).