@inproceedings{39499, abstract = {{3D-graphics popularity has steadily increased in a number of areas such as entertainment, scienti c vi- sualization, simulation, and virtual reality. Despite this rapid growth the authoring of animated 3D objects in virtual environments is stil l by no means trivial. This article presents new concepts of the animated 3D programming language SAM (Solid Agents in Motion) and its programming environment. In SAM, the main syntactic objects like agents, rules, and messages are represented as 3D objects. The design of a SAM pro- gram is supported by a dedicated 3D structure editor. The editor al lows the de nition and spatial arrange- ment of SAM agents in a 3D scene by direct manipu- lation. The paper gives a number of SAM examples, demonstrating the authoring of simple animated vir- tual 3D scenarios.}}, author = {{Geiger, Christian and Lehrenfeld, Georg and Müller, Wolfgang}}, booktitle = {{Proceedings of the Annual Conference for the Computer Human Interaction}}, title = {{{Authoring Communicating Agents in Virtual Environments}}}, year = {{1998}}, } @inproceedings{39493, abstract = {{This article presents the animated visual 3D programming language SAM (Solid Agents in Motion) for parallel systems specification and animation. A SAM program is a set of interacting agents synchronously exchanging messages. The agent's behaviour is specified by means of production rules with a condition and a sequence of actions each. Actions are linearly ordered and execute when matching a rule. In SAM, main syntactic objects like agents, rules, and messages are 3D. These objects can have an abstract and a concrete, solid 3D presentation. While the abstract representation is for programming and debugging, the concrete representation is for animated 3D end-user presentations. After outlining the concepts of SAM this article gives two programming examples of 3D micro worlds and an overview of the programming environment.}}, author = {{Geiger, Christian and Müller, Wolfgang and Rosenbach, W.}}, booktitle = {{Proceedings of the IEEE Symposium on Visual Languages}}, isbn = {{0-8186-8712-6}}, keywords = {{Animation, Computer languages, Solids, Concrete, Application software, Virtual reality, Programming profession, Switches, Visualization, Debugging}}, location = {{Halifax, Canada}}, title = {{{SAM - An Animated 3D Programming Language}}}, doi = {{10.1109/VL.1998.706167}}, year = {{1998}}, } @inproceedings{39489, author = {{Geiger, Christian and Müller, Wolfgang}}, title = {{{Visuelle Spezifikation, Modellierung und Animation im Systementwurf}}}, year = {{1998}}, } @phdthesis{19631, author = {{Bäumker, Armin}}, isbn = {{3-931466-27-2}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}}, title = {{{Communication Efficient Parallel Searching}}}, volume = {{28}}, year = {{1997}}, } @phdthesis{19636, author = {{Dittrich, Wolfgang}}, isbn = {{3-931466-26-4}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}}, title = {{{Communication and I/O Efficient Parallel Data Structures}}}, volume = {{27}}, year = {{1997}}, } @phdthesis{19637, author = {{Strothmann, Willy-Bernhard}}, isbn = {{3-931466-34-5}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}}, title = {{{Bounded Degree Spanning Trees}}}, volume = {{35}}, year = {{1997}}, } @inproceedings{19869, abstract = {{Given a connected graph $G$, let a $dT$-spanning tree of $G$ be a spanning tree of $G$ of maximum degree bounded by $dT$. It is well known that for each $dT ge 2$ the problem of deciding whether a connected graph has a $dT$-spanning tree is NP-complete. In this paper we investigate this problem when additionally connectivity and maximum degree of the graph are given. A complete characterization of this problem for 2- and 3-connected graphs, for planar graphs, and for $dT=2$ is provided. Our first result is that given a biconnected graph of maximum degree $2dT-2$, we can find its $dT$-spanning tree in time $O(m+n^3/2)$. For graphs of higher connectivity we design a polynomial-time algorithm that finds a $dT$-spanning tree in any $k$-connected graph of maximum degree $k(dT-2)+2$. On the other hand, we prove that deciding whether a $k$-connected graph of maximum degree $k(dT-2)+3$ has a $dT$-spanning tree is NP-complete, provided $k le 3$. For arbitrary $k ge 3$ we show that verifying whether a $k$-connected graph of maximum degree $k(dT-1)$ has a $dT$-spanning tree is NP-complete. In particular, we prove that the Hamiltonian path (cycle) problem is NP-complete for $k$-connected $k$-regular graphs, if $k>2$. This extends the well known result for $k=3$ and fully characterizes the case $dT=2$. For planar graphs it is NP-complete to decide whether a $k$-connected planar graph of maximum degree $dG$ has a $dT$-spanning tree for $k=1$ and $dG > dT ge 2$, for $k=2$ and $dG > 2(dT-1) ge 2$, and for $k=3$ and $dG > dT = 2$. On the other hand, we show how to find in polynomial (linear or almost linear) time a $dT$-spanning tree for all other parameters of $k$, $dG$, and $dT$.}}, author = {{Czumaj, Artur and Strothmann, Willy-Bernhard}}, booktitle = {{Proceedings of the Fifth Annual European Symposium on Algorithms (ESA'97)}}, isbn = {{9783540633976}}, issn = {{0302-9743}}, title = {{{Bounded degree spanning trees}}}, doi = {{10.1007/3-540-63397-9_9}}, year = {{1997}}, } @inproceedings{3258, author = {{Rensink, Arend and Wehrheim, Heike}}, booktitle = {{Mathematical Foundations of Computer Science 1997, 22nd International Symposium, MFCS'97, Bratislava, Slovakia, August 25-29, 1997, Proceedings}}, editor = {{Pr{\'{\i}}vara, Igor and Ruzicka, Peter}}, pages = {{468----477}}, title = {{{Dependency-Based Action Refinement}}}, doi = {{10.1007/BFb0029990}}, year = {{1997}}, } @inproceedings{3259, author = {{Rensink, Arend and Wehrheim, Heike}}, booktitle = {{Mathematical Foundations of Computer Science 1997, 22nd International Symposium, MFCS'97, Bratislava, Slovakia, August 25-29, 1997, Proceedings}}, editor = {{Pr{\'{\i}}vara, Igor and Ruzicka, Peter}}, pages = {{468----477}}, title = {{{Dependency-Based Action Refinement}}}, doi = {{10.1007/BFb0029990}}, year = {{1997}}, } @inbook{3029, author = {{Blömer, Johannes}}, booktitle = {{Algorithms — ESA '97}}, isbn = {{9783540633976}}, issn = {{0302-9743}}, pages = {{53--63}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Denesting by bounded degree radicals}}}, doi = {{10.1007/3-540-63397-9_5}}, year = {{1997}}, } @article{3033, author = {{Blömer, Johannes and Karp, Richard and Welzl, Emo}}, journal = {{Random Structures \& Algorithms}}, keywords = {{random matrices, rank, finite fields}}, number = {{4}}, pages = {{407--419}}, title = {{{The rank of sparse random matrices over finite fields}}}, doi = {{10.1002/(SICI)1098-2418(199707)10:4<407::AID-RSA1>3.0.CO;2-Y}}, year = {{1997}}, } @techreport{18955, abstract = {{In this paper we present a (randomized) algorithm for maintaining the biconnected components of a dynamic planar graph of $n$ vertices under deletions of edges. The biconnected components can be maintained under any sequence of edge deletions in a total of $O(n log n)$ time, with high probability. This gives $O(log n)$ amortized time per edge deletion, which improves previous (deterministic) results due to Giammarresi and Italiano, where $O(n log^2 n)$ amortized time is needed. Our work describes a simplification of the data structures from [GiIt96] and uses dynamic perfect hashing to reduce the running time. As in the paper by Giammarresi and Italiano, we only need $O(n)$ space. Finally we describe some simply additional operations on the decremental data structure. By aid of them this the data structure is applicable for finding efficiently a $Delta$-spanning tree in a biconnected planar graph with a maximum degree $2Delta-2$ do to Czumaj and Strothmann.}}, author = {{Strothmann, Willy-Bernhard and Lukovszki, Tamás}}, title = {{{Decremental Biconnectivity on Planar Graphs}}}, year = {{1997}}, } @inproceedings{18575, author = {{Sohler, Christian and Denny, Markus}}, booktitle = {{Proceedings of the 9th Canadian Conference on Computational Geometry}}, pages = {{39--43}}, title = {{{Encoding a Triangulation as a Permutation of its Point Set}}}, year = {{1997}}, } @inproceedings{2175, author = {{Bock, Stefan and Meyer auf der Heide, Friedhelm and Scheideler, Christian}}, booktitle = {{IPPS}}, pages = {{326----332}}, publisher = {{IEEE Computer Society}}, title = {{{Optimal Wormhole Routing in the (n, d)-Torus}}}, year = {{1997}}, } @inproceedings{2179, author = {{Flammini, Michele and Scheideler, Christian}}, booktitle = {{SPAA}}, pages = {{170----179}}, title = {{{Simple, Efficient Routing Schemes for All-Optical Networks}}}, year = {{1997}}, } @proceedings{7795, editor = {{Engels, Gregor}}, number = {{4}}, publisher = {{Springer}}, title = {{{Themenheft: Softwaretechnik}}}, doi = {{http://dx.doi.org/10.1007/s004500050085}}, volume = {{12}}, year = {{1997}}, } @inproceedings{7839, abstract = {{The idea of a combined reference model- and view-based specification approach has been proposed recently in the software engineering community. In this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations supports an intuitive understanding and an integration of static and dynamic aspects on a well-defined semantical base. On this background, formal notions of view and view relation are developed and the behaviour of views is described by a loose semantics. We define a construction for automatic view integration which assumes that the dependencies between different views are described by a reference model. The views and the reference model are kept consistent manually, which is the task of a model manager. All concepts and results are illustrated at the well-known example of a banking system.}}, author = {{Engels, Gregor and Heckel, Reiko and Taentzer, Gabriele and Ehrig, Hartmut}}, booktitle = {{Proceedings European Software Engineering Conference (ESEC 1997), Zürich (Switzerland)}}, editor = {{Jazayeri, M. and Schauer, H.}}, pages = {{327--343}}, publisher = {{Springer}}, title = {{{A View-Oriented Approach to System Modelling Using Graph Transformations}}}, doi = {{http://dx.doi.org/10.1007/3-540-63531-9}}, volume = {{1301}}, year = {{1997}}, } @inproceedings{7840, abstract = {{Vorteile von Laserkristallen in Slab-Geometrie gegenüber Stäben liegen in einer Reduktion der thermisch induzierten Linsenwirkung und der spannungsinduzierten Depolarisation durch einen zick-zack-förmigen Strahlverlauf innerhalb des Kristalls. Durch die Analyse der durch die Anordnung der Pumpquellen und die Dotierungskonzentration bestimmten Temperatur- und Spannungsverteilungen mit Hilfe eines Finite-Element-Modells und die Berechnung der resultierenden optischen Eigenschaften lassen sich die genannten Zielgrößen optimieren. Die Verfahren wurden auf am Laser Zentrum Hannover e.V. entwickelte Nd:YAG-Stab- und Slablaser angewandt und ermöglichten die Entwicklung diodengepumpter Festkörperlaser-Systeme mit Ausgangsleistungen von mehr als 750W bei guter Strahlqualität. Modellerweiterungen unter Berücksichtigung der Wechselwirkung zwischen Lasermoden und aktivem Material werden diskutiert. Diese Arbeit wird gefördert durch das BMBF, FKZ: 13 N 6361}}, author = {{Depke, Ralph and Knoke, Stefan and Schöne, Wolfram and Tünnermann, Andreas and Welling, H.}}, booktitle = {{Verhandlungen der Deutschen Physikalischen Gesellschaft}}, number = {{3}}, publisher = {{Physik-Verlag}}, title = {{{Thermooptische Effekte in Nd:YAG-Slablasern}}}, volume = {{32}}, year = {{1997}}, } @inproceedings{7841, author = {{Heckel, Reiko and Ehrig, Hartmut and Wolter, Uwe and Corradini, Andrea}}, booktitle = {{Proceedings of the 22nd International Symposium on Mathematical Foundations of Computer Science (MFCS 1997), Bratislava (Slovakia)}}, pages = {{219--228}}, publisher = {{Springer}}, title = {{{Integrating the Specification Techniques of Graph Transformation and Temporal Logic}}}, doi = {{http://dx.doi.org/10.1007/BFb0029965}}, year = {{1997}}, } @inproceedings{7842, author = {{Knoke, Stefan and Depke, Ralph and Schöne, Wolfram and Brozek, O.S. and Tünnermann, Andreas and Welling, H.}}, booktitle = {{Verhandlungen der Deutschen Physikalischen Gesellschaft, Weinheim (Germany)}}, number = {{3}}, publisher = {{Physik-Verlag}}, title = {{{Einfrequenzbetrieb von Nd:YAG-Stablasersystemen hoher Ausgangsleistung}}}, volume = {{32}}, year = {{1997}}, }