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).
8186069
On solving large systems of polynomial equations appearing In discrete differential geometry
The poster describes methods that combined find all solutions of a very large overdetermined polynomial algebraic system for only up to 22 unknowns but with billions of equations all homogeneous of degree 8 with on average millions of terms each. This problem resulted from the classification of all integrable 3-dimensional scalar discrete quasilinear equations Q3 = 0 on an elementary cubic cell of the lattice Z3.
27997406
Forward Pruning and Other Heuristic Search Techniques in Tsume Go
Abstract G o T ools is the name of a computer program to analyse life and death fights in the game of go. First, a motivation for programing go is given. General aspects of the heuristic search performed in G o T ools are discussed. The absolute strength and the effect of forward tree pruning are tested in a competition between G o T ools and dan level human players. It is found that with a speed up of a factor of 30 the program still finds for 70% of the problems of a test set the correct first move. A suggestion is made to compare intelligence between contestants (in solving fully enclosed life/death problems) by comparing their relative increase in the time to solve problems with the increase of the difficulty of the problems. The rules of go are explained in the shortest possible form in Appendix A .
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.
27429660
Automatic determination of dynamical symmetries of ordinary differential equations
We describe the application of a computer program CRACKSTAR for the exact analytic solution of overdetermined systems of differential equations which result in determining point-, contact- and dynamical symmetries of ordinary differential equations. Examples are discussed.ZusammenfassungWir beschreiben die Anwendung des Computerprogramms CRACKSTAR zur exakten Lösung überbestimmter Differentialgleichungssysteme, die von der Bestimmung von Punkt- und Berührungssymmetrien sowie dynamischer Symmetrien gewöhnlicher Differentialgleichungen herrühren.
62754021
Transparent replication for fault tolerance in distributed Ada 95
In this paper we present the foundations of RAPIDS ("Replicated Ada Partitions In Distributed Systems"), an implementation of the PCS supporting the transparent replication of partitions in distributed Ada 95 using semi-active replication. The inherently non-deterministic executions of multi-tasked partitions are modeled as piecewise deterministic histories. I discuss the validity and correctness of this model of computation and show how it can be used for efficient semi-active replication. The R APIDS prototype ensures that replicas of a partition all go through the same history and are hence consistent.
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.
41947706
Secure Communication in Distributed Ada
This document describes an implementation of secure communication for distributed applications in Ada 95. It explains the basics of cryptography and introduces the problem of key exchange. After a brief description of distributed systems in Ada 95, the modular structure of the implementation and the way it handles key distribution is presented.
1084067
On exceptions as first-class objects in Ada 95
This short position paper argues that it might be beneficial to try to bring the exception model of Ada 95 more in-line with the object-oriented model of programming. In particular, it is felt that exceptions --- being such an important concept for the development of fault-tolerant software --- have deserved a promotion to first-class objects of the language. It is proposed to resolve the somewhat awkward dichotomy of exceptions and exception occurrences as it exists now in Ada 95 by treating exceptions as (tagged) types, and exception occurrences as their instances.
11330765
Transparent filtering of streams in GLADE
Note: Also available as Technical Report EPFL 97/241 Reference LGL-CONF-1997-009 Record created on 2005-09-20, modified on 2016-08-08