An attempt is made to apply the technique of parallelprocessing to concept learning. A parallel model suited for parallel learning and a parallel learning algorithm obtained from this model by applying the strategy o...
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ISBN:
(纸本)0818620307
An attempt is made to apply the technique of parallelprocessing to concept learning. A parallel model suited for parallel learning and a parallel learning algorithm obtained from this model by applying the strategy of version space are proposed. the time complexity of the algorithm is compared withthat of the sequential learning algorithm, and a satisfactory result is obtained - with N/2 processors, most learning problems can be processed in O(log N) time. the authors also study the influence of the arrangement of the training instances on the performance of their parallel algorithm. the final result shows that when the number of training instances is large, learning in parallel is worthwhile.
the reasons why massively parallel processor systems show such dismal performance are analyzed. the degradation by seriality and communication has been investigated theoretically for linear, rectangular, and square co...
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ISBN:
(纸本)0818620307
the reasons why massively parallel processor systems show such dismal performance are analyzed. the degradation by seriality and communication has been investigated theoretically for linear, rectangular, and square configurations and by experiment on a Transputer system of modifiable dimension from 1 to 4, and up to 16 processors. Eight different application programs run can be grouped into academic and practical problems. they are written in a functional programming language for maximal parallelism. the measured results are analyzed by regression. the quadratic polynomial from the theoretical section shows the best fit. Optimal number of processors, maximal systems performance, and communications factors range from 5 to 14, from 2 to 7, and from 1% to 18%, respectively. Analysis of two experiments from literature on a tightly and a loosely coupled system show similar severe performance degradation, depending on configuration and problem type, with excellent applicability of the theoretical models.
A parallel computation approach to two-dimensional shape recognition is proposed and illustrated. the approach uses parallel techniques for contour extraction, parallel computation of normalized contour-based feature ...
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A parallel computation approach to two-dimensional shape recognition is proposed and illustrated. the approach uses parallel techniques for contour extraction, parallel computation of normalized contour-based feature strings independent of scale and orientation, and parallel string-matching algorithms. the string matching can be applied in a manner independent of rotation. An implementation on the exclusive read, exclusive write parallel random access memory (EREW PRAM) architecture is discussed, but it can be adapted to other parallelarchitectures. An illustrated example is presented.< >
A message-passing multicomputer is presented, and its application to image processing and reconstruction is outlined. the multicomputer may be seen as a one-dimensional array of computing nodes with bidirectional shuf...
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A message-passing multicomputer is presented, and its application to image processing and reconstruction is outlined. the multicomputer may be seen as a one-dimensional array of computing nodes with bidirectional shuffle and shift connections. the resulting shuffle-shift machine is well suited for tasks like image processing and image reconstruction. A sample shuffle-shift machine has been built using transputers. the hardware and software aspects of this implementation are described, and benchmark results obtained with a number of image-oriented algorithms are included. the shuffle-shift machine is compared with related parallel computer architectures, and a two-dimensional generalization is indicated.< >
the authors show how the data parallel programming model can be applied to high level vision tasks needed for object recognition. the architecture and programming model of the Connection Machine System are reviewed. U...
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the authors show how the data parallel programming model can be applied to high level vision tasks needed for object recognition. the architecture and programming model of the Connection Machine System are reviewed. Utilities for representing and manipulating sets of data, the primary representation outside of the image plane, are described using communications primitives, especially segmented scans. Several algorithms for matching and evidence accumulation, which are constructed from the utilities, are compared. the techniques emphasize the use of sorting and sparse representations of space in order to limit the combinatorial processing requirements of high-level vision.< >
Since software has become the major cost driver among the avionics subsystems, a methodology has been developed for definition of advanced avionics architectures with special emphasis on software. It utilizes explicit...
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Since software has become the major cost driver among the avionics subsystems, a methodology has been developed for definition of advanced avionics architectures with special emphasis on software. It utilizes explicit software contributing factors for avionics architecture design and assessment. the methodology is based on a four-step process: definition of candidate data management systems (DMSs), definition of candidate avionics architectures, architecture evaluation from software and other subsystem viewpoints, and architecture evaluation from total avionics system viewpoint. User-defined software contributing factors, along withthose for other subsystems, are used to define and evaluate the architectures objectively. the methodology was applied to a generic avionics system, resulting in a set of candidate avionics architectures and associated evaluation data.< >
An effort has been underway for several years at NASA9;s Langley Research Center to extend the capability of Markov modeling techniques for reliability analysis to the designers of highly reliable avionic systems. ...
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An effort has been underway for several years at NASA's Langley Research Center to extend the capability of Markov modeling techniques for reliability analysis to the designers of highly reliable avionic systems. this effort has been focused in the areas of increased model abstraction and increased computational capability. the reliability model generator (RMG), a software tool which uses as input a graphical, object-oriented block diagram of the system, is discussed. RMG uses an automated failure modes-effects analysis algorithm to produce the reliability model from the graphical description. Also considered is the ASSURE software tool, a parallelprocessing program which uses the ASSIST modeling language and SURE semi-Markov solution technique. An executable failure modes-effects analysis is used by ASSURE. the successful combination of the power of graphical representation, automated model generation, and parallel computation leads to the conclusion that large system architectures can now be analyzed.< >
A system for dynamic intelligent scheduling and control (DISC) of reconfigurable parallel processors is presented. the purpose of the system is to provide a rapid prototyping capability for computer vision/image proce...
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A system for dynamic intelligent scheduling and control (DISC) of reconfigurable parallel processors is presented. the purpose of the system is to provide a rapid prototyping capability for computer vision/image processing tasks. the scheduler particularly addresses the problems of algorithms with execution times that depend on the image data and processing scenarios that vary dynamically based on the input image. Since conventional scheduling methods cannot propose schedules for most masks of this type, a dynamic controller is used to schedule the task and reconfigure the machine on the fly. this dynamic scheduling system attempts to balance the overall processing scenario withthe needs of the individual routines that make up the task. the implementation of this system is discussed, with emphasis on the scheduling heuristics and the use of the system for prototyping computer vision/image processing tasks. Testing was done on a number of tasks that exercised different aspects of the scheduling strategy.< >
Several effective algorithms are presented for the optimal allocation of computer resources in a proposed stream-oriented parallel-processing scheme for database operations. these algorithms can be utilized to obtain ...
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ISBN:
(纸本)0818619538
Several effective algorithms are presented for the optimal allocation of computer resources in a proposed stream-oriented parallel-processing scheme for database operations. these algorithms can be utilized to obtain the optimal allocation of memory resources for every type of query in sequential-processing environments, parallel-processing environments with shared-memory multiprocessors, and distributed-processing environments. the computation complexities of the proposed algorithms are analyzed and used to clarify the effectiveness of those algorithms.
A network is proposed that preserves all of the properties of the hypercube, but has a diameter which is only about half of that of the hypercube. this network is self-routing, in the sense that there is a simple dist...
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ISBN:
(纸本)0818619538
A network is proposed that preserves all of the properties of the hypercube, but has a diameter which is only about half of that of the hypercube. this network is self-routing, in the sense that there is a simple distributed routing algorithm which guarantees optimal paths between any pair of vertices. this fact, together with other properties such as regularity, symmetry, high connectivity, and a simple recursive structure, implies that the multiply twisted cube is an alternative to the ordinary hypercube for massively parallelarchitectures. Single-input multiple-data stream algorithms were developed which utilize the new architecture. the multiply-twisted hypercube architecture can be used to profitably emulate the ordinary hypercube. Some of the basic properties of this network are discussed, the programming issues are emphasized, and it is shown that any hypercube algorithm can be mapped to run on the new architecture. In many cases this mapping results in a substantial reduction in the running time due to more efficient routing of data between processors.
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