Using coordination to parallelize sparse-grid methods for 3D CFD problems

The good parallel computing properties of sparse-grid solution techniques are investigated. For this, an existing sequential CFD code for a standard 3D problem from computational aerodynamics is restructured into a parallel application. The restructuring is organized according to a master/slave protocol. The coordinator modules developed thereby are implemented in the coordination language Manifold and are generally applicable. Performance results are given for both the sequential and parallel version of the code. The results are promising, the paper contributes to the state-of-the-art in improving the efficiency of large-scale computations. Also a theoretical analysis is made of speed-up through parallelization in a multi-user single-machine environment

Coordination of a parallel proposition solver

In this paper we describe an experiment in which {sc Manifold is used to coordinate the interprocess communication in a parallelized proposition solver. {sc Manifold is very well suited for applications involving dynamic process creation and dynamically changing (ir)regular communication patterns among sets of independent concurrent cooperating processes. The idea in this case study is simple. The proposition solver consists of a fixed numbers of separate processing units which communicate with each other such that the output of one serves as the input for the other. Because one of the processing units performs a computation intensive job, we introduce a master/worker protocol to divide its computations. We show that this protocol implemented in {sc Manifold adds another hierarchic layer to the application but leaves the previous layers intact. This modularity of {sc Manifold offers the possibility to introduce concurrency step by step. We also verify the implementation of the proposition solver using a simple family of assertions and give some performance results

Coordination of distributed/parallel multiple-grid domain decomposition

A workable approach for the solution of many (numerical and non-numerical) problems is domain decomposition. If a problem can be divided into a number of sub-problems that can be solved in a distributed/parallel fashion, the overall performance can significantly improve. In this paper, we discuss one of our experiments using the new coordination language MANIFOLD to solve an instance of the classical optimization problem by domain decomposition. We demonstrate the applicability of MANIFOLD in expressing the solutions to domain decomposition problems in a generic way and its utility in producing executable code that can carry out such solutions in both distributed and parallel environments. The multiple-grid domain decomposition method used in this paper is based on adaptive partitioning of the domain and results in highly irregular grids as shown in the examples. The implementation of the distributed/parallel approach presented in this paper looks very promising and its coordinator modules are generally applicable

Parallel, distributed-memory implementation of sparse-grid methods for three-dimensional fluid-flow computations

A workable approach for modernization of existing software into parallel/distributed applications is through coarse-grain restructuring. If, for instance, entire subroutines of legacy code can be plugged into a new structure, the investment required for the re-discovery o

Parallel, distributed-memory implementation of a sparse-grid method for time-dependent advection-diffusion problems

A workable approach for modernizing existing software into parallel/distributed applications is through coarse-grain restructuring. If, for instance, entire subroutines of legacy code can be plugged into a new structure, the investment required for the re-discovery of the d

Reusability of coordination programs

Isolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability, and reusability of parallel and/or distributed software. This can be achieved by moving communication primitives (such as SendMessage and ReceiveMessage), which are now commonly scattered in application codes, into separate modules written in a language dedicated to the coordination of processes and the flow of information among them. MANIFOLD is a pure coordination language that encourages the separation of communication and computation concerns, We use real, concrete, running MANIFOLD programs to demonstrate the concept of pure coordination modules and the advantage of their reuse in applications of different nature

Manual of spIds, a software package for parameter identification in dynamic systems

This report contains the manual of spIds, version 1.0, a software package for parameter identification in dynamic systems. SpIdslabel{ab:spIds is an acronym of underline{simulation and underline{parameter underline{identification in underline{dynamic underline {systems. It can be applied on wide variety of dynamic systems which can be described by a set of ordinary differential equations or differential algebraic equations. The manual describes briefly the general principles of the underlying mathematics and the structure of the software package. The preparations for the input are described in detail. The documentation of the Graphical User Interface is also quite explicit