An Immersive Telepresence System using RGB-D Sensors and Head Mounted Display

We present a tele-immersive system that enables people to interact with each other in a virtual world using body gestures in addition to verbal communication. Beyond the obvious applications, including general online conversations and gaming, we hypothesize that our proposed system would be particularly beneficial to education by offering rich visual contents and interactivity. One distinct feature is the integration of egocentric pose recognition that allows participants to use their gestures to demonstrate and manipulate virtual objects simultaneously. This functionality enables the instructor to ef- fectively and efficiently explain and illustrate complex concepts or sophisticated problems in an intuitive manner. The highly interactive and flexible environment can capture and sustain more student attention than the traditional classroom setting and, thus, delivers a compelling experience to the students. Our main focus here is to investigate possible solutions for the system design and implementation and devise strategies for fast, efficient computation suitable for visual data processing and network transmission. We describe the technique and experiments in details and provide quantitative performance results, demonstrating our system can be run comfortably and reliably for different application scenarios. Our preliminary results are promising and demonstrate the potential for more compelling directions in cyberlearning.Comment: IEEE International Symposium on Multimedia 201

The LAB@FUTURE Project - Moving Towards the Future of E-Learning

This paper presents Lab@Future, an advanced e-learning platform that uses novel Information and Communication Technologies to support and expand laboratory teaching practices. For this purpose, Lab@Future uses real and computer-generated objects that are interfaced using mechatronic systems, augmented reality, mobile technologies and 3D multi user environments. The main aim is to develop and demonstrate technological support for practical experiments in the following focused subjects namely: Fluid Dynamics - Science subject in Germany, Geometry - Mathematics subject in Austria, History and Environmental Awareness – Arts and Humanities subjects in Greece and Slovenia. In order to pedagogically enhance the design and functional aspects of this e-learning technology, we are investigating the dialogical operationalisation of learning theories so as to leverage our understanding of teaching and learning practices in the targeted context of deployment

Static Analysis of Run-Time Errors in Embedded Real-Time Parallel C Programs

We present a static analysis by Abstract Interpretation to check for run-time errors in parallel and multi-threaded C programs. Following our work on Astr\'ee, we focus on embedded critical programs without recursion nor dynamic memory allocation, but extend the analysis to a static set of threads communicating implicitly through a shared memory and explicitly using a finite set of mutual exclusion locks, and scheduled according to a real-time scheduling policy and fixed priorities. Our method is thread-modular. It is based on a slightly modified non-parallel analysis that, when analyzing a thread, applies and enriches an abstract set of thread interferences. An iterator then re-analyzes each thread in turn until interferences stabilize. We prove the soundness of our method with respect to the sequential consistency semantics, but also with respect to a reasonable weakly consistent memory semantics. We also show how to take into account mutual exclusion and thread priorities through a partitioning over an abstraction of the scheduler state. We present preliminary experimental results analyzing an industrial program with our prototype, Th\'es\'ee, and demonstrate the scalability of our approach

Design Environments for Complex Systems

The paper describes an approach for modeling complex systems by hiding as much formal details as possible from the user, still allowing verification and simulation of the model. The interface is based on UML to make the environment available to the largest audience. To carry out analysis, verification and simulation we automatically extract process algebras specifications from UML models. The results of the analysis is then reflected back in the UML model by annotating diagrams. The formal model includes stochastic information to handle quantitative parameters. We present here the stochastic -calculus and we discuss the implementation of its probabilistic support that allows simulation of processes. We exploit the benefits of our approach in two applicative domains: global computing and systems biology

Symbol Synchronization Techniques in Digital Communications

Timing synchronization plays an important role in recovering the original transmitted signal in telecommunication systems. In order to have a communication system that operates at the correct time and in the correct order, it is necessary to synchronize to the transmitter’s symbol timing. Synchronization can be accomplished when the receiver clock tracks the periodic timing information in a transmitted signal to reproduce the original signal. In this thesis work, we report the design, implementation and evaluation of a timing synchronization algorithm based on the technique first proposed by Gardner [1], applied to wireless communication using the Alamouti spacetime code [2] under QPSK modulation with halfsine pulses. To achieve this, a mathematical model is introduced which includes software design of communication algorithms. In this modeling, we simulate the Gardner algorithm in MATLAB. Then, five techniques are introduced to improve the performance of the loop filter in the digital receiver, and they are successfully implemented and evaluated in Matlab. These five techniques prove that there is an improvement in digital receiver performance in terms of the convergence speed and the communication system complexity. On the other hand, the optimum decoding of the Alamouti spacetime code, as initially proposed, makes the nontrivial assumption that the communication system is perfectly synchronized. Realistic wireless environments contain additive white Gaussian noise (AWGN), multipath fading, and it is not perfectly synchronized. In this thesis, the Alamouti spacetime code technique is written for QPSK modulation scheme to work in realistic environment that involves a timing synchronization technique. We compare the bit error rate (BER) of the Alamouti decoder when synchronized using the proposed algorithms with the ideal results found in the literature, and we find them to be similar, proving that the synchronization algorithm is in fact achieving optimum synchronization. This thesis presents synchronization algorithms that are necessary for a complete working wirelessAlamouti technique. Also, this thesis improves the communication system performance in terms of the convergence speed with reducing the computational complexity of the communication system design