检索结果-内蒙古大学图书馆

A fast general algorithm for extracting image features on SIMD mesh-connected computers

PATTERN RECOGNITION 1997年第7期30卷 1205-1211页

作者： Shi, HC Ritter, GX Wilson, JN UNIV FLORIDA DEPT COMP & INFORMAT SCIGAINESVILLEFL 32611

Extracting features of components in an image is an important step for recognition of objects in the image. In this paper, we develop a general formula for extracting some geometric features of image components such as area, perimeter, compactness, height, width, diameter, moments, and centroid. We then design a fast algorithm for the general formula on SIMD mesh-connected computers. The algorithm uses a pipelining technique to compute a geometric property of kn components at the same time. It takes O([m/kn]n) time to compute a geometric property of all the components in an n x n image on an n x n SIMD mesh-connected computer with O(k) local space in each processing element, where m is the number of components in the image and k is an integer between 1 and [m/n]. Compared with previous algorithms, it speeds up the feature extraction process by at least k times. (C) 1997 Pattern Recognition Society.

关键词： feature extraction parallel algorithm mesh-connected computer pipelining technique geometric features

来源：评论

学校读者我要写书评

暂无评论

A multipole direct and indirect BEM for 2D cavity flow at low Reynolds number

引用

ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS 1997年第1期19卷 17-31页

作者： Gomez, JE Power, H WESSEX INST TECHNOL SOUTHAMPTON SO40 7AAHANTSENGLAND

A multipolar methodology is applied to the boundary element method (direct and indirect formulation) in order to solve bidimentional Stokes cavity flow. The algorithm based on mixed multipolar expansion and numerical integration is applied not only for very large problems but also for intermediate and small problems. In comparison with the direct formulation, the indirect formulation is more stable with the iterative solvers, and does not need to be preconditioned to obtain a fast convergence. A good result in memory saving and computing time is obtained that enables us to run huge examples which are prohibitive for traditional BEM implementations. (C) 1997 Elsevier Science Ltd.

关键词： creeping viscous flow fast multipole-clustering boundary element method parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

The equivalence of the chessboard distance transform and the medial axis transform

引用

INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 1997年第3-4期65卷 165-177页

作者： Lee, YH Horng, SJ Natl Taiwan Inst Technol Dept Elect Engn Taipei Taiwan

The distance transform (DT) and the medial axis transform (MAT) are two image computation tools used to extract the information about the shape and the position of the foreground pixels relative to each other. The DT converts a binary image into an image, where each pixel has a value to represent the distance from it to its nearest foreground pixel. The MAT of an image is a set of maximal squares that represents the foreground pixels of an image. Extensively applications of these two transforms are used in the fields of computer vision and image processing, such as expanding shrinking, thinning and computing shape factor etc. There are many different distance transforms based on different distance metrics. The chessboard distance transform (CDT) is one kind of distance transform (DT) which converts an image based on the chessboard distance metrics. In this paper, we first demonstrate that both transforms (i.e. MAT and CDT) are interchangeable. Then the corresponding algorithms are also proposed. That is, the MAT can be found by utilizing a CDT algorithm and vice versa. That is also true in any computation models.

关键词： algorithms computer vision distance transform image processing medial axis transform parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Solving an algebraic path problem and some related graph problems on a hyper-bus broadcast network

引用

IEEE TRANSACTIONS ON parallel AND DISTRIBUTED SYSTEMS 1997年第12期8卷 1226-1235页

作者： Tsai, HR Horng, SJ Tsai, SS Kao, TW Lee, SS Overseas Chinese Coll Commerce Dept Informat Management Taichung Taiwan Natl Taiwan Univ Sci & Technol Dept Elect Engn Taipei Taiwan Kuang Wu Inst Technol & Commerce Dept Elect Engn Taipei Taiwan Fu Shin Inst Technol & Commerce Dept Elect Engn Ilan Taiwan

The parallel computation model upon which the proposed algorithms are based is the hyper-bus broadcast network. The hyper-bus broadcast network consists of processors which are connected by global buses only. Based on such an improved architecture, we first design two O(1) time basic operations for finding the maximum and minimum of N numbers each of size O(log N)-bit and computing the matrix multiplication operation of two Nx N matrices, respectively. Then, based on these two basic operations, three of the most important instances in the algebraic path problem, the connectivity problem, and several related problems are all solved in O(log N) time. These include the all-pair shortest paths, the minimum-weight spanning tree, the transitive closure, the connected component, the biconnected component, the articulation point, and the bridge problems, either in an undirected or a directed graph, respectively.

关键词： hyper-bus broadcast network parallel algorithm graph theory matrix multiplication operation algebraic path problem connectivity all-pair shortest paths minimum-weight spanning tree transitive closure connected component biconnected component articulation point bridge

来源：评论

学校读者我要写书评

暂无评论

A parallelizable eigensolver for real diagonalizable matrices with real eigenvalues

引用

SIAM JOURNAL ON SCIENTIFIC COMPUTING 1997年第3期18卷 869-885页

作者： HussLederman, S Tsao, A Turnbull, T Center for Computing Sciences Bowie MD 20715 17100 Science Drive United States

In this paper, preliminary research results on a new algorithm for finding all the eigenvalues and eigenvectors of a real diagonalizable matrix with real eigenvalues are presented. The basic mathematical theory behind this approach is reviewed and is followed by a discussion of the numerical considerations of the actual implementation. The numerical algorithm has been tested on thousands of matrices on both a Gray-2 and an IBM RS/6000 Model 580 workstation. The results of these tests are presented. Finally, issues concerning the parallel implementation of the algorithm are discussed. The algorithm's heavy reliance on matrix-matrix multiplication, coupled with the divide and conquer nature of this algorithm, should yield a highly parallelizable algorithm.

关键词： eigenvalues divide and conquer algorithm invariant subspaces parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Multi-parameter error resolution for the collocation method of Volterra integral equations

引用

BIT 1997年第4期37卷 978-987页

作者： Zhou, AH Acad Sinica Inst Syst Sci Beijing 100080 Peoples R China

In this paper, a multi-parameter error resolution technique is introduced and applied to the collocation method for Volterra integral equations. By using this technique, an approximation of higher accuracy is obtained by using a multi-processor in parallel. Additionally, a correction scheme for approximation of higher accuracy and a global superconvergence result are presented.

关键词： collocation integral equations multi-parameter error resolution parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Potentials in undirected graphs and planar multiflows

引用

SIAM JOURNAL ON COMPUTING 1997年第2期26卷 582-603页

作者： Sebo, A CNRS LEIBNIZ-IMAG 38031 Grenoble Cedex 1 46 Avenue Félix Viallet France

The duality relation between shortest paths and potentials in directed graphs and the significance of both of these in the theory of network flows is well known. In this paper, we work out the analogous undirected notions, which neither are contained in nor contain their directed counterpart. They are more related to matching theory than to network flows: the corresponding min-path-max-potential theorem can be considered a weighted generalization of the Gallai-Edmonds structure theorem for matchings. In our earlier work [J. Combin. Theory Ser. B, 49 (1990), pp. 10-39], the corresponding theorems are proved in the special case of +/-1 bipartite weightings, and this special case already contains the main points of the general proof. The goal of the present paper is to extrapolate from this +/-1-weighted bipartite special case the arbitrarily weighted general min-path-max-potential theorem and to show some algorithmic consequences related to planar multiflows, the Chinese postman problem, the weighted and unweighted matching structure, etc. In order to make this paper self-contained, we also include a compact, revised variant of earlier proofs, adapted to the present context. In addition to good characterization theorems and polynomial algorithms, efficient (logarithmic polynomial) parallel algorithms follow for some of these problems.

关键词： T-joins T-cuts multicommodity flows Chinese postman matching structure parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

A width-independent sequential thinning algorithm

引用

INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE 1997年第3期11卷 393-403页

作者： Bhattacharya, P Lu, X UNIV NEBRASKA DEPT COMP SCI & ENGNLINCOLNNE 68588

We propose a new sequential width-independent thinning algorithm for binary images. The algorithm uses a 4-neighbor distance transformation, and is designed to preserve the topological properties and shape of the obje... 详细信息

关键词： thinning medial axis transformation width-independent parallel algorithm skeleton connecting paths

来源：评论

学校读者我要写书评

暂无评论

Implementation of an optimal parallel algorithm for arithmetic expression parsing

Implementation of an optimal parallel algorithm for arithmet...

引用

IEEE 1st International Conference on algorithms and Architectures for parallel Processing (ICA3PP 95)

作者： Hungenahally, S GRIFFITH UNIV FAC SCI & TECHNOLSIGNAL PROC & INTELLIGENT SYST RES LABBRISBANEQLD 4111AUSTRALIA

ISBN: (纸本)0780320182

Development of efficient algorithms for parallel computer architectures is an on-going research area and in the recent past a great volume of theoretical work has been carried out for the search of suitable algorithms in concurrent processing environment. In this paper, the results obtained in the implementation of an Optimal parallel algorithm developed by Deng and Iyengar (1992) in the esoteric area of arithmetic expression parsing is reported. The 'C' code developed and tested on an IBM Compatible Personal Computer in this investigative study, is a simple recursive descent parser and may be used for parallel parsing of arithmetic expressions. The algorithm was developed to suit the SIMD parallel architecture to avoid any communication bottlenecks posed by PVM system, however, design and structure of the code readily permits portability to a parallel computer system.< >

关键词： parser parallel algorithm SIMD PVM

来源：评论

学校读者我要写书评

暂无评论

parallel finite element Laplace transform method for the non-equilibrium groundwater transport equation

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 1997年第14期40卷 2653-2664页

作者： Pini, G Putti, M Dip. di Metodi Scienze Applicate Univ. degli Studi di Padova 35131 Padova via Belzoni 7 Italy

Groundwater transport of contaminants undergoing rate-limited or non-equilibrium sorption onto the solid matrix is often described by the dual-porosity or two-domain model, whereby the rate-limited reaction occurs between a mobile and an immobile region. When the sorption reaction is represented by a first-order kinetic relationship, the equation takes the form of a convection-dispersion partial differential equation with an integral term describing the mass transfer between the two regions. An efficient solution algorithm for this type of problems consists in the transformation of the original equation into the Laplace space and subsequent numerical solution of the resulting steady-state equation in the complex space. The exploitation of the Laplace transform to solve the time dependency restricts the application of the technique to linear advection and dispersion terms, while non-linear reactions can be accommodated in particular cases only. This approach has the advantage that it is easily parallelizable, and is therefore proposed in this paper as an efficient algorithm for the parallelization in time of these types of integrodifferential equations. The parallel efficiency of PFELT has been tested on a Gray T3D parallel computer for three sample problems of size N = 1071, 3721, and 15 275, respectively, where N is the number of nodal mesh points. The speed-ups obtained vary from 1.98, with two processors, to 39.93 with 64 processors, for the most favorable case. This corresponds to a percentage of parallel work greater than 98 per cent, and a parallel efficiency of more than 60 per cent in the best case, showing the good performance achievable with this algorithm. (C) 1997 by John Wiley & Sons, Ltd.

关键词： groundwater transport non-equilibrium sorption Laplace transformation finite element parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：