Superscalar implementations of RISC architectures are emerging as the dominant high-performance microprocessor technology for the mid-1990's. For instruction-level parallelism to increase beyond present levels, mu...
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ISBN:
(纸本)9780818652806
Superscalar implementations of RISC architectures are emerging as the dominant high-performance microprocessor technology for the mid-1990's. For instruction-level parallelism to increase beyond present levels, multiple memory operations per cycle are required. The paper evaluates several alternatives for two-ported data cache memory systems. A new split data cache memory design is compared to a more conventional true dual-ported memory. Experimental simulations are used to determine the performance benefits of these cache models on superscalar processors. These experiments are reported for a contemporary processor with modest instruction-level parallelism and for a hypothetical very aggressive, highly parallel processor.< >
We propose a simple quasi-static routing scheme for buffered mesh connected network computers. Under the assumption of uniform traffic demands, it is demonstrated numerically that our simple routing scheme achieves ne...
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ISBN:
(纸本)0818626720
We propose a simple quasi-static routing scheme for buffered mesh connected network computers. Under the assumption of uniform traffic demands, it is demonstrated numerically that our simple routing scheme achieves near-optimal performance;in the sense of minimizing the total number of outstanding packets in a Jackson-type network. Simulation results are also presented for the case of non-uniform traffic demands. These simulations illustrate that our quasi-static control scheme can dynamically adjust the values of routing probabilities so as to provide acceptable and stable network performance. The results of these simulations are displayed using advanced video graphics.
Animation of algorithms makes understanding them intuitively easier. This paper describes the software tool Raft (Robust Animator of Fault Tolerant Algorithms) which allows the user to animate a number of fault tolera...
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Animation of algorithms makes understanding them intuitively easier. This paper describes the software tool Raft (Robust Animator of Fault Tolerant Algorithms) which allows the user to animate a number of fault tolerant parallel algorithms which achieve fault tolerant execution. The novelty of the system is that the interface allows the user to create new on-line fault-injecting adversaries as the algorithm executes. The various algorithms animated adapt to this interactive input in order to ensure fault-tolerance. The system has an extensive user interface which allows a choice of the number of processors, the number of parallel tasks, and the adversary to control the processor failures.< >
A 3-D interpolation method is proposed as the preprocessing step for 3-D visualization to compensate the poor interslice resolution in 3-D medical imaging. The proposed method uses the surface information which is obt...
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A 3-D interpolation method is proposed as the preprocessing step for 3-D visualization to compensate the poor interslice resolution in 3-D medical imaging. The proposed method uses the surface information which is obtained at each voxel using local gradients. If the voxel to be interpolated is found on a surface or in its vicinity, interpolation is performed along the direction parallel to the surface; otherwise interpolation is done along the vertical z-direction. Since the method uses correlation information inherent in 3-D data effectively, it can provide the interpolated image which preserves the surface smoothness and also reduces the interpolation error near the surface. As experimental results, volume rendering and cut-view images of interpolated 3-D medical data are presented.< >
A technique for automatically adding graphics code to application programs is described. It has been found that many visualization strategies can be described solely in terms of the productions in the programming lang...
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ISBN:
(纸本)0818620536
A technique for automatically adding graphics code to application programs is described. It has been found that many visualization strategies can be described solely in terms of the productions in the programming language's BNF;therefore, a source-to-source transformation mechanism, whereby a user's nongraphics application can be transformed into a consistently functioning variant that also has graphics display operations methodically inserted, is being implemented. The ultimate goal is to discover principles whereby some clear image of an application's state can be communicated to a user by automatic source code analysis. The initial step has been to focus on a concrete architecture, the Connection Machine (CM), for which a set of high-level display functions has been fixed. Source programs written in C, and containing high-level directives, are passed through a parser and analysis program, which creates a variant program having graphics code installed. When compiled and run in the usual way, the transformed program will initialize the CM frame buffer and display state variables at strategic times during the application's execution. The transformation program implemented for the experiments is called CmVis. It has been prototyped using a parser generator called NewYacc, a Yacc-based tool that is enhanced by allowing rewrite rules to be associated with the language's BNF productions.
A description is given of ideas and tools that help with the visualization of sparse matrix computations. The Sparse Matrix Manipulation System, an environment for handling sparse matrices of all types in a flexible m...
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A description is given of ideas and tools that help with the visualization of sparse matrix computations. The Sparse Matrix Manipulation System, an environment for handling sparse matrices of all types in a flexible manner via ASCII file interfaces, is used. Two commands in this environment are ShowMatrix and ShowTree. The first illustrates the pattern of nonzeroes of a sparse matrix. The second illustrates dependencies among matrix elements. Other tools in the package are described, including tools for ordering, factoring and multiplying sparse matrices. This software environment is then used to study the effect of several recent ordering and partitioning algorithms for working with the sparse inverses of L and U. These new algorithms have been proposed as a means of enhancing the parallelism of sparse matrix computations. The effect of these algorithms on parallelism and fill-in is illustrated in a graphic manner.< >
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