45184054
A package for the analytic investigation and exact solution of differential equations
To find exact solutions of differential equations fDEs) one usually performs a variety of tests and ansaetze as e.g. the symmetry ansatz, separation ansatz, ansaetze for first integrals. When carrying through these ideas one h a s to solve overdetermined systems of partial DEs fPDEs). Whereas the formulation of the overdetermined system f o r each ansatz is achieved by different programs we use one program to investigate the overdetermined sys~. This program CRAOKSTAR contains three basic modules for the deooupling of DEs, for the integration of exact DEs and f o r separation. They are explained by examples. With these new a b i l i t i e s i t becomes poss ib le f o r CRACKSTAR to so lve systems of DEs which are sore difficult, i.e. the ansatz to be carried through ma y be less restrictive. An example shows that in this way not only point s y m m e t r i e s b u t a l s o m o r e g e n e r a l d y n a m i c a l s y m m e t r i e s o f o r d i n a r y DEs ( O D E s ) c a n b e d e t e r m i n e d . F o r t h e I n v e s t i g a t i o n o f L l e s ~ t r i e s o f systems of PDEs an interval strategy is applied which reduces the effort f o r GKACKSTM~ c o n s i d e r a b l y . F u r t h e r t w o new c o n c e p t s , a n i n t e g r a l a n s a t z f o r ODEs and a generalized separation ansatz f o r PDEs are described as w e l l a s t h e p r o g r a m s w h i c h g e n e r a t e o v e r d e t e r m i n e d s y s t e m s for e a c h ansatz.
46113649
Analytical Decoupling, Decision of Compatibility and Partial Integration of Systems of Non-Linear Ordinary and Partial Differential Equations
1703030
Optimizing GoTools' Search Heuristics using Genetic Algorithms
GoTools is a program which solves life & death problems in the game of Go. This paper describes experiments using a Genetic Algorithm to optimize heuristic weights used by GoTools' tree-search. The complete set of heuristic weights is composed of different subgroups, each of which can be optimized with a suitable fitness function. As a useful side product, an MPI interface for FreePascal was implemented to allow the use of a parallelized fitness function running on a Beowulf cluster. The aim of this exercise is to optimize the current version of GoTools, and to make tools available in preparation of an extension of GoTools for solving open boundary life & death problems, which will introduce more heuristic parameters to be fine tuned.
5578706
Checking Life-and Death Problems in Go
895386
Size Reduction and Partial Decoupling of Systems of Equations
A method is presented that reduces the number of terms of systems of linear equations (algebraic, ordinary and partial differential equations). As a byproduct these systems have a tendency to become partially decoupled and are more likely to be factorizable or integrable. A variation of this method is applicable to nonlinear systems. Modifications to improve efficiency are given and examples are shown. This procedure can be used in connection with the computation of the radical of a differential ideal (differential Grobner basis).
3233905
Programs for applying symmetries
In this paper the programs APPLYSYM, QUASILINPDE and DETRAFO are described which aim at the utilization of infinitesimal symmetries of differential equations. The purpose of QUASILINPDE is the general solution of quasilinear PDEs. This procedure isusedby APPLYSYM fortheapplication of point symmetries for either Q calculating simila,rity variables toperform a point transformation which lowers the order of an ODEoreffectiveiy reduces the number of explicitly occuringindependent variablesin aPDE(-system) or for . generalizing given special solutions of ODEs/PDEs with new constant parameters. The program DETRAFO performs arbitrary pointand contact transformations of ODEs/PDEs and is applied if similarity and symmetry variables have been found. The program APPLYSYM is used in connection with the program LIEPDE for formulating and solving the conditions for pointand cent act symmetries which is described in [4]. The actual problem solving is done in all these programs through a call to the package CRACK for solving overdetermined PDE systems.
40351745
Vom Rechenzentrum zum Zentrum für Informations- und Kommunikationstechnik
Belege fur die technische Unterstutzung der menschlichen Informationsverarbeitung finden sich bis weit in die Vergangenheit. Die historischen Entwicklungslinien der drei Teilfunktionen der Informations- und Kommunikationstechnologie (IuK-Technik) — Transport, Verarbeitung und Speicherung — sind lange Zeit getrennt verlaufen. Hiermit ist gemeint, das die technischen Losungen fur die der drei Teilfunktionen unabhangig waren.
30440565
Ein optisches Meßsystem zur Echtzeitanalyse von Konturen mit der PLL-Schaltung
Mit einer einfachen analogen Phasenmestechnik, der PLL-Schaltung, lassen sich Phasenmessungen mit hoher Genauigkeit in Echtzeit realisieren. Insbesondere in optischen Messystemen, in denen mit einer Phasenbestimmung aus einem harmonischen Intensitatsmuster die gesuchte physikalische Mesgrose extrahiert werden mus, stellt die hier vorgestellte Methode eine lohnende Alternative zu den bekannten digitalen Auswertemethoden dar. Dabei entfallen sowohl die Beschrankung auf statische Phasenbilder sowie Problematiken bei der Phasenentfaltung. Die Konturmessung an einem Kalibrierkor per sowie ein Versuch zur Bestimmung des Kriechverhaltens eines PE-Schaumes werden als Beispielmessungen vorgestellt.
15117189
Global Biclustering of Microarray Data
We consider the problem of simultaneously clustering genes and conditions of a gene expression data matrix. A bicluster is defined as a subset of genes that show similar behavior within a subset of conditions. Finding biclusters can be useful for revealing groups of genes involved in the same molecular process as well as groups of conditions where this process takes place. Previous work either deals with local, bicluster-based criteria or assumes a very specific structure of the data matrix (e.g. checkerboard or block-diagonal) (Ryan et al., 2005). In contrast, our goal is to find a set of flexibly arranged biclusters which is optimal in regard to a global objective function. As this is a NP-hard combinatorial problem, we describe several techniques to obtain approximate solutions. We benchmarked our approach successfully on the Alizadeh B-cell lymphoma data set (Alizadeh et al., 2000)
43214033
Ein neuer Ansatz zur Lösung der Phasenentfaltungsproblematik
Ein durch eine harmonische Intensitatsverteilung beschreibbares Streifenmuster soll ausgewertet werden. Dabei mus fur jeden Punkt des Musters die Phasenlage bestimmt werden. Mit auto-matischen Phasenauswertemethoden last sich im allgemeinen die Phase nur im sich periodisch fortsetzenden Werteintervall [−π, π] bestimmen (Sagezahnbild). Das Zusammensetzen zur Gesamtphase wird als Phasenentfaltung bezeichnet. Die Anwendung des Streifenprojektions-verfahrens [Breu93] zur Konturbestimmung von Schaumstoffoberflachen in Kombination mit der Phasenshifttechnik fuhrt zu einem Sagezahnbild, dessen automatische Entfaltung bei Anwendung von ublichen Methoden zu erheblichen Fehlern fuhrt. Oftmals ist nur eine interaktive Phasenkorrektur durch den Benutzer moglich. Mit Hilfe der Fuzzy-Logik kann man das menschliche Expertenwissen in einer vom Computer verarbeitbaren Form fur die automatische Phasenentfaltung zur Verfugung stellen.
1643372
Fault Tolerance by Transparent Replication for Distributed Ada 95
This paper presents the foundations of RAPIDS ("Replicated Ada Partitions In Distributed Systems"), an implementation of the Distributed Systems Annex E incorporating the transparent replication of partitions in distributed Ada 95 applications. RAPIDS is a replication manager for semi-active replication based on a piecewise deterministic computation model. It guarantees replica consistency for arbitrary Ada 95 partitions despite the inherent non-determinism of multitasking, offering k-resilient partitions. The RAPIDS prototype is implemented for the GNAT compiler and evolved from its PCS, Garlic.