TY - CONF AU - Böttcher, Stefan AU - Hartel, Rita AU - Stey, Sebastian ID - 15100 SN - 0302-9743 T2 - Advances in Databases - 28th British National Conference on Databases, BNCOD 28, Revised Selected Papers TI - TraCX: Transformation of Compressed XML ER - TY - CHAP AB - Given a set of n mobile robots in the d-dimensional Euclidean space, the goal is to let them converge to a single not predefined point. The challenge is that the robots are limited in their capabilities. Robots can, upon activation, compute the positions of all other robots using an individual affine coordinate system. The robots are indistinguishable, oblivious and may have different affine coordinate systems. A very general discrete time model assumes that robots are activated in arbitrary order. Further, the computation of a new target point may happen much earlier than the movement, so that the movement is based on outdated information about other robot's positions. Time is measured as the number of rounds, where a round ends as soon as each robot has moved at least once. In [Cohen, Peleg: Convergence properties of gravitational algorithms in asynchronous robot systems], the Center of Gravity is considered as target function, convergence was proven, and the number of rounds needed for halving the diameter of the convex hull of the robot's positions was shown to be O(n^2) and Omega(n). We present an easy-to-check property of target functions that guarantee convergence and yields upper time bounds. This property intuitively says that when a robot computes a new target point, this point is significantly within the current axes aligned minimal box containing all robots. This property holds, e.g., for the above-mentioned target function, and improves the above O(n^2) to an asymptotically optimal O(n) upper bound. Our technique also yields a constant time bound for a target function that requires all robots having identical coordinate axes. AU - Cord-Landwehr, Andreas AU - Degener, Bastian AU - Fischer, Matthias AU - Hüllmann, Martina AU - Kempkes, Barbara AU - Klaas, Alexander AU - Kling, Peter AU - Kurras, Sven AU - Märtens, Marcus AU - Meyer auf der Heide, Friedhelm AU - Raupach, Christoph AU - Swierkot, Kamil AU - Warner, Daniel AU - Weddemann, Christoph AU - Wonisch, Daniel ID - 16409 SN - 0302-9743 T2 - Automata, Languages and Programming TI - A New Approach for Analyzing Convergence Algorithms for Mobile Robots ER - TY - CONF AB - We introduce the Read-Write-Coding-System (RWC) – a very flexible class of linear block codes that generate efficient and flexible erasure codes for storage networks. In particular, given a message x of k symbols and a codeword y of n symbols, an RW code defines additional parameters k \leq r,w \leq n that offer enhanced possibilities to adjust the fault-tolerance capability of the code. More precisely, an RWC provides linear $\left(n,k,d\right)$-codes that have (a) minimum distance d=n-r+1 for any two codewords, and (b) for each codeword there exists a codeword for each other message with distance of at most w. Furthermore, depending on the values r,w and the code alphabet, different block codes such as parity codes (e.g. RAID 4/5) or Reed-Solomon (RS) codes (if r=k and thus, w=n) can be generated. In storage networks in which I/O accesses are very costly and redundancy is crucial, this flexibility has considerable advantages as r and w can optimally be adapted to read or write intensive applications; only w symbols must be updated if the message x changes completely, what is different from other codes which always need to rewrite y completely as x changes. In this paper, we first state a tight lower bound and basic conditions for all RW codes. Furthermore, we introduce special RW codes in which all mentioned parameters are adjustable even online, that is, those RW codes are adaptive to changing demands. At last, we point out some useful properties regarding safety and security of the stored data. AU - Mense, Mario AU - Schindelhauer, Christian ID - 19796 SN - 0302-9743 T2 - Proceedings of 11th International Symposium on Stabilization, Safety, and Security of Distributed Systems TI - Read-Write-Codes: An Erasure Resilient Encoding System for Flexible Reading and Writing in Storage Networks VL - 5873 ER - TY - CONF AU - Hamann, Heiko AU - Meyer, Bernd AU - Schmickl, Thomas AU - Crailsheim, Karl ID - 20226 SN - 0302-9743 T2 - From Animals to Animats 11 TI - A Model of Symmetry Breaking in Collective Decision-Making VL - 6226 ER - TY - JOUR AU - Grza̧ślewicz, Ryszard AU - Kutyłowski, Jarosław AU - Kutyłowski, Mirosław AU - Pietkiewicz, Wojciech ID - 24282 JF - ICCSA'05: Proceedings of the 2005 international conference on Computational Science and Its Applications SN - 0302-9743 TI - Robust Undetectable Interference Watermarks ER - TY - CHAP AU - Ackermann, Marcel R. AU - Blömer, Johannes ID - 2988 SN - 0302-9743 T2 - SWAT 2010 TI - Bregman Clustering for Separable Instances ER - TY - CHAP AB - Self-healing promises to improve the dependability of systems. In particular safety-critical systems like automotive systems are well suited application, since safe operation is required in these systems even in case of failures. Prerequisite for the improved dependability is the correct realization of the self-healing techniques. Consequently, self-healing activities should be rigorously specified and appropriately integrated with the rest of the system. In this paper, we present an approach for designing self-healing mechanisms in automotive systems. The approach contains a construction model which consist of a structural description as well as an extensive set of constraints. The constraints specify a correct system structure and are also used in the self-healing activities. We exemplify the self-healing approach using the adaptive cruise control system of modern cars. AU - Seebach, Hella AU - Nafz, Florian AU - Holtmann, Jörg AU - Meyer, Jan AU - Tichy, Matthias AU - Reif, Wolfgang AU - Schäfer, Wilhelm ID - 20961 SN - 0302-9743 T2 - Lecture Notes in Computer Science TI - Designing Self-healing in Automotive Systems ER - TY - CONF AU - Briest, Patrick AU - Chalermsook, Parinya AU - Khanna, Sanjeev AU - Laekhanukit, Bundit AU - Nanongkai, Danupon ID - 19029 SN - 0302-9743 T2 - Workshop on Internet and Network Economics (WINE) TI - Improved Hardness of Approximation for Stackelberg Shortest-Path Pricing ER - TY - CHAP AB - We present an approach for real-time rendering of complex 3D scenes consisting of millions of polygons on limited graphics hardware. In a preprocessing step, powerful hardware is used to gain fine granular global visibility information of a scene using an adaptive sampling algorithm. Additively the visual influence of each object on the eventual rendered image is estimated. This influence is used to select the most important objects to display in our approximative culling algorithm. After the visibility data is compressed to meet the storage capabilities of small devices, we achieve an interactive walkthrough of the Power Plant scene on a standard netbook with an integrated graphics chipset. AU - Eikel, Benjamin AU - Jähn, Claudius AU - Fischer, Matthias ID - 16505 SN - 0302-9743 T2 - Advances in Visual Computing TI - Preprocessed Global Visibility for Real-Time Rendering on Low-End Hardware ER - TY - CONF AU - Böttcher, Stefan AU - Hartel, Rita AU - Messinger, Christian ID - 15137 SN - 0302-9743 T2 - Database and XML Technologies - 7th International XML Database Symposium, XSym 2010 TI - Searchable Compression of Office Documents by XML Schema Subtraction ER -