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.
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).
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
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.
46113649
Analytical Decoupling, Decision of Compatibility and Partial Integration of Systems of Non-Linear Ordinary and Partial Differential Equations
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.
31197886
Object-Oriented Programming and Protected Objects in Ada 95
Integrating concurrent and object-oriented programming has been an active research topic since the late 1980s. The majority of approaches have taken a sequential object-oriented language and made it concurrent. A few approaches have taken a concurrent language and made it object-oriented. The most important of this latter class is the Ada 95 language which is an extension to the object-based concurrent programming language Ada 83. Arguably, Ada 95 does not fully integrate its models of concurrency and object-oriented programming. This paper discusses ways in which protected objects can be made more extensible.
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)
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.
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