A kinematic analysis and mechanism description of a biglide parallel grinder with six-controlled degree of freedom is presented in this paper. In comparison with hexapod machines, the mechanical structure and motion o...
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A kinematic analysis and mechanism description of a biglide parallel grinder with six-controlled degree of freedom is presented in this paper. In comparison with hexapod machines, the mechanical structure and motion of this biglide parallel grinder are simple. therefore, it is easy for this biglide parallel grinder to accomplish real-time control. Its workspace-to-volume ratio is even larger than that of conventional machine tools, and there is also no singularity configuration. Because of using parallel fixed length links, this biglide parallel grinder can reduce the thermal deformation effects on its accuracy. In addition to grinding, this grinder can be used for welding, painting, fixturing, material handling and so on. (C) 2003 Published by Elsevier Science B.V.
In this paper three strategies are described to restore dynamically the load balancing in parallel active set optimization algorithms. the efficiency of our proposals is shown by comparison with other heuristics descr...
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this paper presents the design and experimental evaluation of two dynamic load partitioning and balancing strategies for parallel Structured Adaptive Mesh Refinement (SAMR) applications: the Level-based Partitioning A...
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ISBN:
(纸本)354040788X
this paper presents the design and experimental evaluation of two dynamic load partitioning and balancing strategies for parallel Structured Adaptive Mesh Refinement (SAMR) applications: the Level-based Partitioning Algorithm (LPA) and the Hierarchical Partitioning Algorithm (HPA). these techniques specifically address the computational and communication heterogeneity across refinement levels of the adaptive grid hierarchy underlying these methods. An experimental evaluation of the partitioning schemes is also presented.
this paper describes how the specific access structure of the Brusselator equation, a typical example for ordinary differential equations (ODEs) derived by the method of lines, can be exploited to obtain scalable dist...
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ISBN:
(纸本)354040788X
this paper describes how the specific access structure of the Brusselator equation, a typical example for ordinary differential equations (ODEs) derived by the method of lines, can be exploited to obtain scalable distributed-memory implementations of explicit Runge-Kutta (RK) solvers. these implementations need less communication and therefore achieve better speed-ups than general explicit RK implementations. Particularly, we consider implementations based on a pipelining computation scheme leading to an improved locality behavior.
We describe the implementation of ASSIST, a programming environment for parallel and distributed programs. Its coordination language is based of the parallel skeleton model, extended with new features to enhance expre...
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ISBN:
(纸本)354040788X
We describe the implementation of ASSIST, a programming environment for parallel and distributed programs. Its coordination language is based of the parallel skeleton model, extended with new features to enhance expressiveness, parallel software reuse, software component integration and interfacing to external resources. the compilation process and the structure of the run-time support of ASSIST are discussed with respect to the issues introduced by the new characteristics, presenting an analysis of the first test results.
A general real-space multigrid-based program package MIKA (Multigrid Instead of the K-spAce) for the self-consistent solution of the Kohn-Sham equations appearing in the state-of-the-art electronic structure calculati...
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A general real-space multigrid-based program package MIKA (Multigrid Instead of the K-spAce) for the self-consistent solution of the Kohn-Sham equations appearing in the state-of-the-art electronic structure calculations is described. the most important part of the method is the multigrid solver for the Schrodinger equation. Our choice is the Rayleigh quotient multigrid method (RQMG), which applies directly to the minimization of the Rayleigh quotient on the finest level. Coarse correction grids can be used because there is in principle no need to represent the states on the coarse levels. the RQMG method is generalized for the simultaneous solution of all the states of the system using a penalty functional to keep the states orthogonal. Special care has been taken to optimize the iterations toward the self-consistency and run the code in parallel computer architectures. the scheme has been implemented in multiple geometries. We show examples from electronic structure calculations employing nonlocal pseudopotentials and/or the jellium model. the RQMG solver is also applied for the calculation of positron states in solids. (C) 2002 Wiley Periodicals, Inc.
A robot simulation system has been used not only as a design and simulation tool, but it also serves as an off-line programming system for industrial robots and other machines with a computer integrated manufacture (C...
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A robot simulation system has been used not only as a design and simulation tool, but it also serves as an off-line programming system for industrial robots and other machines with a computer integrated manufacture (CIM) system. A robot simulation system is one of the essential elements for virtual manufacturing and agile manufacturing. A post-processor is an important element of an off-line robot programming system, as it allows the commercially available robot simulation systems to be used as off-line robot programming tools. the post-processor translates output statements from a robot simulator to a target robot language. Typically, the sequence of motion and data required to drive the robot can be transmitted through the use of a serial or parallel data link, between an off-line computer and a robot controller. the design of a general post-processor capable of translating the output of multiple robot simulators to multiple robot programming languages is an extremely complex problem. there are two basic ways of describing robot movements in robot control systems;one describes the manipulator movements in terms of the manipulator end-effector location (in compound transformation or absolute);whilst the other describes the movements in terms of manipulator joint angles. the former approach is suitable for future and present generation robots with a language processor installed in their controllers, whilst the latter is only specifically linked to earlier generation robot languages. Discrepancies between a specific robot simulation system and a real robot system which should be resolved as part of the post-processing, are analysed. the feasibility of generalising the post-processor was studied. In this paper different approaches of post-processing for off-line programs and methods of downloading off-line programs to robot controller are discussed also. (C) 2003 Elsevier Science B.V. All rights reserved.
When designing and implementing highly efficient scientific applications for parallel computers such as clusters of workstations, it is inevitable to consider and to optimize the single-CPU performance of the codes. F...
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ISBN:
(纸本)354040788X
When designing and implementing highly efficient scientific applications for parallel computers such as clusters of workstations, it is inevitable to consider and to optimize the single-CPU performance of the codes. For this purpose, it is particularly important that the codes respect the hierarchical memory designs that computer architects employ in order to hide the effects of the growing gap between CPU performance and main memory speed. In this paper, we present techniques to enhance the single-CPU efficiency of lattice Boltzmann methods which are commonly used in computational fluid dynamics. We show various performance results to emphasize the effectiveness of our optimization techniques.
parallel programming environments provide a way for users to reap the benefits of parallelism, while reducing the effort required to create parallel applications. the CO2P3S parallel programming system is one such too...
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ISBN:
(纸本)354040788X
parallel programming environments provide a way for users to reap the benefits of parallelism, while reducing the effort required to create parallel applications. the CO2P3S parallel programming system is one such tool, using a pattern-based approach to express concurrency. this paper demonstrates that the CO2P3S system contains a rich set of parallel patterns for implementing a wide variety of applications running on shared-memory or distributed-memory hardware. Code metrics and performance results are presented to show the usability of the CO2P3S system and its ability to reduce programming effort, while producing programs with reasonable performance.
Skeletons are reusable, parameterized components with well-defined semantics and pre-packaged efficient parallel implementation. this paper develops a new, provably cost-optimal implementation of the DS (double-scan) ...
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ISBN:
(纸本)354040788X
Skeletons are reusable, parameterized components with well-defined semantics and pre-packaged efficient parallel implementation. this paper develops a new, provably cost-optimal implementation of the DS (double-scan) skeleton for the divide-and-conquer paradigm. Our implementation is based on a novel data structure called plist (pointed list);implementation's performance is estimated using an analytical model. We demonstrate the use of the DS skeleton for parallelizing a tridiagonal system solver and report experimental results for its MPI implementation on a Cray T3E and a Linux cluster: they confirm the performance improvement achieved by the cost-optimal implementation and demonstrate its good predictability by our performance model.
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