Parallel Virtual Machine System Research Articles

Parallel and distributed adaptive quadrilateral mesh generation

A parallel quadrilateral mesh generation using advanced front technology is presented in this paper. An improved quadrilateral mesh generation technology which uses the advancing front technology was introduced by the authors previously. This new quadrilateral mesh generation technique has been developed for use with parallel computing environments. The parallel code has been created by adapting the sequential code using each coarse quadrilateral as a sub-domain for remeshing. A transputer-based parallel system and a heterogeneous network of workstations using the parallel virtual machine system were employed. The use of these parallel environments to improve the efficiency of the proposed mesh generator was investigated. Some pre-processes have been introduced to ensure load balancing during the parallel mesh generation. A post processor has been developed to assist in the assembly of the distributed portions of the mesh. Four examples are presented to demonstrate the robustness and efficiency of this parallel mesh generator. Some nearly linear speed-up curves have been achieved for some large meshes by using up to 11 transputers.

A multi‐level frontal algorithm for finite element analysis and its implementation on parallel computation

This paper presents a multi‐level frontal algorithm and its implementation and applications on parallel computation. A multi‐frontal program is given which may be used for unsymmetric finite element matrix equations. The parallel program is developed on a cluster of workstations. The PVM (parallel virtual machine) system is used to handle communications among networked workstations. The method has advantages such as numbering of the finite element mesh in an arbitrary manner, simple programming organisation, smaller core requirements and computation times. An implementation of this parallel method on workstations is discussed, the speedup and efficiency of this method being demonstrated and compared with general domain decomposition method based on band matrix methods by numerical examples.

A multi-frontal parallel algorithm for coupled thermo-hydro-mechanical analysis of deforming porous media

In this paper, a multi-frontal parallel algorithm is developed to solve fully coupled heat, water and gas flow in deformable porous media. The mathematical model makes use of the modified e⁄ective stress concept together with the capillary pressure relationship and takes phase change and latent heat transfer into account. The chosen macroscopic field variables are displacement, capillary pressure, gas pressure and temperature. The parallel program is developed on a cluster of workstations. The PVM (Parallel Virtual Machine) system is used to handle communications among networked workstations. The multi-frontal method has advantages such as numbering of the finite element mesh in an arbitrary manner, simple programming organization, smaller core requirements and shorter computation times. An implementation of this parallel method on workstations is discussed. The speedup and eƒciency of this method is demonstrated and compared with a general domain decomposition method based on band matrix methods by numerical examples. ( 1998 John Wiley & Sons, Ltd.

JPVM: network parallel computing in Java

The JPVM library is a software system for explicit message-passing based distributed memory MIMD parallel programming in Java. The library supports an interface similar to the C and Fortran interface provided by the Parallel Virtual Machine (PVM) system, but with syntax and semantics modifications afforded by Java and better matched to Java programming styles. The similarity between JPVM and the widely used PVM system supports a quick learning curve for experienced PVM programmers, thus making the JPVM system an accessible, low-investment target for migrating parallel applications to the Java platform. At the same time, JPVM offers novel features not found in standard PVM such as thread safety, multiple communication end-points per task, and default-case direct message routing. JPVM is implemented entirely in Java, and is thus highly portable among platforms supporting some version of the Java Virtual Machine. This feature opens up the possibility of utilizing resources commonly excluded from network parallel computing systems such as Macintosh and Windows-NT based systems. Initial applications performance results achieved with a prototype JPVM system indicate that the Java-implemented approach can offer good performance at appropriately coarse granularities.

PVM communication performance over an ATM MAN

This paper presents results of the performance tests of the PVM system over an ATM Metropolitan Area Network (MAN). PVM (Parallel Virtual Machine) is a communication package, which is considered currently a de facto standard for the development of high-performance distributed applications. ATM (Asynchronous Transfer Mode) is the emerging cell-switching technology for high-speed networks. This work is part of the experiments of heterogeneous network computing in the framework of the Neanet Project. Neanet is one of the first public high-speed networks based on ATM. The ultimate goal of the experiments is to assess the effectiveness of ATM geographical networks for high-performance computing. Besides allowing comparison with local area networks, the FVM performance figures are useful per se in the design and in the predictive performance evaluation of distributed applications on ATM networks.

A parallel algorithm for thermo-hydro-mechanical analysis of deforming porous media

In this paper, a parallel Newton-Raphson algorithm with domain decomposition is developed to solve fully coupled heat, water and gas flow in deformable porous media. The model makes use of the modified effective stress concept together with the capillary pressure relationship. Phase change and latent heat transfer are also taken into account. The chosen macroscopic field variables are displacement, capillary pressure, gas pressure and temperature. The parallel program is developed on a cluster of workstations. The PVM (Parallel Virtual Machine) system is used to handle communications among networked workstations. An implementation of this parallel method on workstations is discussed, the speedup and efficiency of this method being demonstrated by numerical examples.

Performance of IBM RISC System/6000 workstation clusters in a quantum chemical application

The performance of clusters of IBM RISC System/6000 family of workstations in a quantum chemical application (electron correlation energy calculations using concurrent computation many-body perturbation theory) is assessed. The Parallel Virtual Machine System (PVM) is used to distribute various parts of the calculation among the workstations. The use of both homogeneous and heterogeneous clusters of workstations is investigated. The performance characteristics are compared with data recently obtained for the CRAY Y-MP C-90 and NEC SX-3/44 computers.

Network‐based concurrent computing on the PVM system

AbstractConcurrent computing environments based on loosely coupled networks have proven effective as resources for multiprocessing. Experiences with and enhancements to version 1.0 of PVM (Parallel Virtual Machine) are described in this paper. PVM is a software package that allows the utilization of a heterogeneous network of parallel and serial computers as a single computational resource. This report also describes an interactive graphical interface to PVM, and porting and performance results from production applications.

Genetic Algorithms On Distributed Systems

A distributed implementation of Genetic Algorithms (GA) to solve Job Shop Scheduling problems is discussed The initial part of the paper introduces the highlights of GA and their application to Job Shop Scheduling problems A few words are also spent in describing the PVM (Parallel Virtual Machine) system that was adopted to implement the distributed application on a workstation network. The main discussion of the paper is devoted to the solution of the problems encountered in the GA implementation. The strategies adopted for improving the performance of our solution, both in terms of goodness of the numerical results and in terms of parallelism efficiency, are also discussed. As far as the distributed solution is concerned, the paper reports a set of tests to evaluate the relative performance indexes of the used workstations To this end, the response times of the whole distributed application on each individual machine, when varying the number of the parallel searches, are considered. Finally, the results of the distributed searches, with the co-operating processes distributed among all the available workstations, are presented. These results are compared with those of the previous calculations to give a performance evaluation of parallelism in terms of relative speedup and efficiency.