TY - CONF
AU - Groenewegen, Luuk
AU - Engels, Gregor
ID - 8266
T2 - Proceedings of the 4th European Workshop on Software Process Technology (EWSPT 1995), Noordwijkerhout (The Netherlands)
TI - Coordination by Behavioural Views and Communication Patterns
VL - 913
ER -
TY - CONF
AB - Based on a categorical semantics that has been developed for typed graph grammars we uses colimits (pushouts) to model composition and (reverse) graph grammar morphisms to describe refinements of typed graph grammars. Composition of graph grammars w.r.t. common subgrammars is shown to be compatible with the semantics, i.e. the semantics of the composed grammar is obtained as the composition of the semantics of the component grammars. Moreover, the structure of a composed grammar is preserved during a refinement step in the sense that compatible refinements of the components induce a refinement of the composition. The concepts and results are illustrated by an example.
AU - Corradini, Andrea
AU - Heckel, Reiko
ID - 8267
T2 - Proceedings of the Joint COMPUGRAPH/SEMAGRAPH Workshop on Graph Rewriting and Computation (SEGRAGRA 1995), Volterra (Italy)
TI - A Compositional Approach to Structuring and Refinement of Typed Graph Grammars
VL - 2
ER -
TY - CONF
AB - The overall aim of this paper is a proposal how to bridge the gap between formal specification techniques developed in research projects and semi--formal or informal specifications used in industrial practice. The main idea to overcome these problems is to develop graphical support for formal methods in order to increase acceptance by practitioners and to provide means for integration of formal and semi--formal methods. More specifically suitable concepts will be developed to combine algebraic specifications, Petri Nets, and Graph Grammars with each other and with distinguished graphical components to be used by industrial partners.
AU - Bardohl, Bernhard
AU - Bardohl, Roswitha
AU - Castro, Paulo
AU - Ehrig, Hartmut
AU - Heckel, Reiko
AU - Ribeiro, Leila
AU - Nunes, Daltro
AU - Martini, Alfio
ID - 8268
T2 - Proceedings of the 3rd German-Brazilian Workshop on Information Technology (1995), Berlin (Germany)
TI - GRAPHIT: Graphical Support and Integration of Formal and Semiformal Methods for Software Specification and Development
VL - 26
ER -
TY - CONF
AB - Currently existing graph grammar-based specification languages have serious problems with supporting any kind of “specification-in-the-large” activities. More precisely, they have deficiencies with respect to modeling hierarchical data structures or specifying meta activities like manipulation of graph schemata. Furthermore, already proposed graph grammar module concepts are still too abstract to be useful in practice. Our contribution addresses these problems by introducing a new hierarchical graph data model with an infinite number of schema, meta-schema, etc. layers. It forms the base for a forthcoming concrete modular graph grammar specification language where in addition information hiding aspects like explicit export and import interfaces are expressible.
AU - Engels, Gregor
AU - Schürr, Andy
ID - 8269
T2 - Proceedings of the Joint COMPUGRAPH/SEMAGRAPH Workshop on Graph Rewriting and Computation (SEGRAGRA 1995), Volterra (Italy)
TI - Encapsulated Hierarchical Graphs, Graph Types, and Meta Types
ER -
TY - CONF
AU - Heckel, Reiko
AU - Wagner, Annika
ID - 8270
T2 - Proceedings of the Joint COMPUGRAPH/SEMAGRAPH Workshop on Graph Rewriting and Computation (SEGRAGRA 1995), Volterra (Italy)
TI - Ensuring Consistency of Conditional Graph Grammars - A constructive Approach
VL - 2
ER -
TY - CHAP
AU - Kremer, H.-Hugo
ED - Braukmann, U.
ED - Diettrich, A.
ED - Kremer, H.-H.
ED - Sloane, P.F.E.
ED - Stickling, E.
ID - 8354
T2 - Meisterprüfung - Lernen für die Praxis - Unternehmensführung 1
TI - Existenzgründung
ER -
TY - JOUR
AB - In an array of coupled oscillators, synchronous chaos may occur in the sense that all the oscillators behave identically although the corresponding motion is chaotic. When a parameter is varied this fully symmetric dynamical state can lose its stability, and the main purpose of this paper is to investigate which type of dynamical behavior is expected to be observed once the loss of stability has occurred. The essential tool is a classification of Lyapunov exponents based on the symmetry of the underlying problem. This classification is crucial in the derivation of the analytical results but it also allows an efficient computation of the dominant Lyapunov exponent associated with each symmetry type. We show how these dominant exponents determine the stability of invariant sets possessing various instantaneous symmetries, and this leads to the idea of symmetry breaking bifurcations of chaotic attractors. Finally, the results and ideas are illustrated for several systems of coupled oscillators.
AU - Aston, Philip J.
AU - Dellnitz, Michael
ID - 16510
JF - International Journal of Bifurcation and Chaos
SN - 0218-1274
TI - Symmetry Breaking Bifurcations of Chaotic Attractors
ER -
TY - JOUR
AU - Dellnitz, M
AU - Heinrich, C
ID - 16532
JF - Nonlinearity
SN - 0951-7715
TI - Admissible symmetry increasing bifurcations
ER -
TY - JOUR
AU - Dellnitz, M
AU - Melbourne, I
ID - 16542
JF - Nonlinearity
SN - 0951-7715
TI - A note on the shadowing lemma and symmetric periodic points
ER -
TY - JOUR
AU - Dellnitz, Michael
AU - Field, Michael
AU - Golubitsky, Martin
AU - Ma, Jun
AU - Hohmann, Andreas
ID - 16550
JF - International Journal of Bifurcation and Chaos
SN - 0218-1274
TI - Cycling Chaos
ER -
TY - JOUR
AB - Spiral patterns have been observed experimentally, numerically, and theoretically in a variety of systems. It is often believed that these spiral wave patterns can occur only in systems of reaction–diffusion equations. We show, both theoretically (using Hopf bifurcation techniques) and numerically (using both direct simulation and continuation of rotating waves) that spiral wave patterns can appear in a single reaction–diffusion equation [ in u(x, t)] on a disk, if one assumes "spiral" boundary conditions (ur = muθ). Spiral boundary conditions are motivated by assuming that a solution is infinitesimally an Archimedian spiral near the boundary. It follows from a bifurcation analysis that for this form of spirals there are no singularities in the spiral pattern (technically there is no spiral tip) and that at bifurcation there is a steep gradient between the "red" and "blue" arms of the spiral.
AU - Dellnitz, Michael
AU - Golubitsky, Martin
AU - Hohmann, Andreas
AU - Stewart, Ian
ID - 16551
JF - International Journal of Bifurcation and Chaos
SN - 0218-1274
TI - Spirals in Scalar Reaction–Diffusion Equations
ER -
TY - JOUR
AU - Breslauer, Dany
AU - Czumaj, Artur
AU - Dubhashi, Devdatt P.
AU - Meyer auf der Heide, Friedhelm
ID - 16566
JF - Information Processing Letters
SN - 0020-0190
TI - Transforming comparison model lower bounds to the parallel-random-access-machine
ER -
TY - CHAP
AU - Golubitsky, Martin
AU - Marsden, Jerrold
AU - Stewart, Ian
AU - Dellnitz, Michael
ID - 16611
SN - 9780821803264
T2 - Normal Forms and Homoclinic Chaos
TI - The constrained Liapunov-Schmidt procedure and periodic orbits
ER -
TY - CHAP
AU - Meyer auf der Heide, Friedhelm
AU - Vöcking, Berthold
ID - 16704
SN - 0302-9743
T2 - STACS 95
TI - A packet routing protocol for arbitrary networks
ER -
TY - CHAP
AU - Czumaj, Artur
AU - Meyer auf der Heide, Friedhelm
AU - Stemann, Volker
ID - 16705
SN - 0302-9743
T2 - Lecture Notes in Computer Science
TI - Shared memory simulations with triple-logarithmic delay
ER -
TY - CONF
AU - Meyer auf der Heide, Friedhelm
AU - Storch, Martin
AU - Wanka, Rolf
ID - 16706
SN - 0897917170
T2 - Proceedings of the seventh annual ACM symposium on Parallel algorithms and architectures - SPAA '95
TI - Optimal trade-offs between size and slowdown for universal parallel networks
ER -
TY - CONF
AU - Czumaj, Artur
AU - Meyer auf der Heide, Friedhelm
AU - Stemann, Volker
ID - 16707
SN - 0818669152
T2 - Proceedings Third Israel Symposium on the Theory of Computing and Systems
TI - Improved optimal shared memory simulations, and the power of reconfiguration
ER -
TY - CHAP
AU - Meyer auf der Heide, Friedhelm
AU - Westermann, Matthias
ID - 16717
SN - 0302-9743
T2 - Graph-Theoretic Concepts in Computer Science
TI - Hot-potato routing on multi-dimensional tori
ER -
TY - CHAP
AU - Bäumker, Armin
AU - Dittrich, Wolfgang
AU - Meyer auf der Heide, Friedhelm
ID - 16874
SN - 0302-9743
T2 - Lecture Notes in Computer Science
TI - Truly efficient parallel algorithms: c-optimal multisearch for an extension of the BSP model
ER -
TY - JOUR
AU - Platzner, Marco
AU - Rinner, Bernhard
AU - Weiss, Reinhold
ID - 10610
JF - J.UCS Journal of Universal Computer Science
TI - Exploiting Parallelism in Constraint Satisfaction for Qualitative Simulation
VL - 12
ER -