5578706
Checking Life-and Death Problems in Go
19107527
Investigating DEs with CRACK and related programs
The aim of the package to be described is to try modularizing the investigation of differential equations for which there are no complete algorithms available yet. All, that is available for such problems are algorithms for special situations, e.g. when first integrals with a simple structure exist (e.g. polynomial in first derivatives) or when the problem has infinitesimal symmetries. In all such cases, finally a system of differential equations has to be solved which is overdetermined in the sense that more conditions have to be satisfied than there are unknown functions. To do a variety of such investigations efficiently, like a symmetry analysis, application of symmetries, determination of first integrals, differential factors, equivalent Lagrangians, the strategy is to have one package (CRACK) for simplifying DEs and solving simple DEs as effective as possible and to use this program as the main tool for all the above mentioned investigations. For each investigation there is then only a short program necessary to just formulate the necessary conditions in form of an overdetermined DE-system and to call CRACK to solve this, possibly in a number of successive calls. The examples below shall indicate the range of possible applications.
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 .
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.
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.
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).
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
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.
23941957
Model Checking
Die Gewährleistung der korrekten
Funktionsweise von Hard- und Software ist ein entscheidender
Faktor bei der heutigen Systementwicklung. Dies trifft ganz
besonders auf das Gebiet der sog. „sicherheitskritischen“
Systeme zu, bei dem ein Systemversagen Menschenleben gefährden
kann.
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.
35587806
Ein Fuzzy geregeltes optisches Meßsystem zur Messung von 3D-Verformungn
Es wird ein optischer Mesplatz zur beruhrungslosen Verformungsmessung an Proben aus Polymerschaum vorgestellt. Dabei werden zwei bewahrte optische Mesmethoden, ein als digitale Specklephotographie bezeichnetes Korrelationsverfahren und das Projektionsstreifenverfahren miteinander kombiniert, um das dreidimensionale Verschiebungsvektorfeld auf der Probenoberflache zu ermitteln. Grose Dehnungen fuhren bei der Verwendung der digitalen Specklephotographie zu Dekorrelationen, die die Anwendbarkeit des Mesverfahrens beschranken. Durch die Verarbeitung von Vorinformationen und den Einsatz von Fuzzylogik ist es gelungen, den Anwendungsbereich fur beide Mesverfahren zu erweitern.