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112
Memory Coherence in Shared Virtual Memory Systems
, 1989
"... This paper studies the memory coherence problem in designing said inaplementing a shared virtual memory on looselycoupled multiprocessors. Two classes of aIgoritb. ms for solving the problem are presented. A prototype shared virtual memory on an Apollo ring has been implemented based on these a ..."
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Cited by 893 (16 self)
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This paper studies the memory coherence problem in designing said inaplementing a shared virtual memory on looselycoupled multiprocessors. Two classes of aIgoritb. ms for solving the problem are presented. A prototype shared virtual memory on an Apollo ring has been implemented based on these algorithms. Both theoretical and practical results show tkat the mentory coherence problem cast indeed be solved efficiently on a looselycoupled multiprocessor.
The Watershed Transform: Definitions, Algorithms and Parallelization Strategies
, 2001
"... The watershed transform is the method of choice for image segmentation in the field of mathematical morphology. We present a critical review of several definitions of the watershed transform and the associated sequential algorithms, and discuss various issues which often cause confusion in the li ..."
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Cited by 140 (3 self)
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The watershed transform is the method of choice for image segmentation in the field of mathematical morphology. We present a critical review of several definitions of the watershed transform and the associated sequential algorithms, and discuss various issues which often cause confusion in the literature. The need to distinguish between definition, algorithm specification and algorithm implementation is pointed out. Various examples are given which illustrate differences between watershed transforms based on different definitions and/or implementations. The second part of the paper surveys approaches for parallel implementation of sequential watershed algorithms.
A Functional Approach to External Graph Algorithms
 Algorithmica
, 1998
"... . We present a new approach for designing external graph algorithms and use it to design simple external algorithms for computing connected components, minimum spanning trees, bottleneck minimum spanning trees, and maximal matchings in undirected graphs and multigraphs. Our I/O bounds compete w ..."
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Cited by 89 (2 self)
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. We present a new approach for designing external graph algorithms and use it to design simple external algorithms for computing connected components, minimum spanning trees, bottleneck minimum spanning trees, and maximal matchings in undirected graphs and multigraphs. Our I/O bounds compete with those of previous approaches. Unlike previous approaches, ours is purely functionalwithout side effectsand is thus amenable to standard checkpointing and programming language optimization techniques. This is an important practical consideration for applications that may take hours to run. 1 Introduction We present a divideandconquer approach for designing external graph algorithms, i.e., algorithms on graphs that are too large to fit in main memory. Our approach is simple to describe and implement: it builds a succession of graph transformations that reduce to sorting, selection, and a recursive bucketing technique. No sophisticated data structures are needed. We apply our t...
Waitfree Parallel Algorithms for the UnionFind Problem
 In Proc. 23rd ACM Symposium on Theory of Computing
, 1994
"... We are interested in designing efficient data structures for a shared memory multiprocessor. In this paper we focus on the UnionFind data structure. We consider a fully asynchronous model of computation where arbitrary delays are possible. Thus we require our solutions to the data structure problem ..."
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Cited by 50 (0 self)
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We are interested in designing efficient data structures for a shared memory multiprocessor. In this paper we focus on the UnionFind data structure. We consider a fully asynchronous model of computation where arbitrary delays are possible. Thus we require our solutions to the data structure problem have the waitfree property, meaning that each thread continues to make progress on its operations, independent of the speeds of the other threads. In this model efficiency is best measured in terms of the total number of instructions used to perform a sequence of data structure operations, the work performed by the processors. We give a waitfree implementation of an efficient algorithm for UnionFind. In addition we show that the worst case performance of the algorithm can be improved by simulating a synchronized algorithm, or by simulating a larger machine if the data structure requests support sufficient parallelism. Our solutions apply to a much more general adversary model than has be...
The Computational Power and Complexity of Constraint Handling Rules
 In Second Workshop on Constraint Handling Rules, at ICLP05
, 2005
"... Constraint Handling Rules (CHR) is a highlevel rulebased programming language which is increasingly used for general purposes. We introduce the CHR machine, a model of computation based on the operational semantics of CHR. Its computational power and time complexity properties are compared to thos ..."
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Cited by 50 (21 self)
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Constraint Handling Rules (CHR) is a highlevel rulebased programming language which is increasingly used for general purposes. We introduce the CHR machine, a model of computation based on the operational semantics of CHR. Its computational power and time complexity properties are compared to those of the wellunderstood Turing machine and Random Access Memory machine. This allows us to prove the interesting result that every algorithm can be implemented in CHR with the best known time and space complexity. We also investigate the practical relevance of this result and the constant factors involved. Finally we expand the scope of the discussion to other (declarative) programming languages.
An Optimal Algorithm for Generating Minimal Perfect Hash Functions
 Information Processing Letters
, 1992
"... A new algorithm for generating order preserving minimal perfect hash functions is presented. The algorithm is probabilistic, involving generation of random graphs. It uses expected linear time and requires a linear number words to represent the hash function, and thus is optimal up to constant facto ..."
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Cited by 43 (1 self)
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A new algorithm for generating order preserving minimal perfect hash functions is presented. The algorithm is probabilistic, involving generation of random graphs. It uses expected linear time and requires a linear number words to represent the hash function, and thus is optimal up to constant factors. It runs very fast in practice. Keywords: Data structures, probabilistic algorithms, analysis of algorithms, hashing, random graphs
Implementing the DantzigFulkersonJohnson Algorithm for Large Traveling Salesman Problems
, 2003
"... Dantzig, Fulkerson, and Johnson (1954) introduced the cuttingplane method as a means of attacking the traveling salesman problem; this method has been applied to broad classes of problems in combinatorial optimization and integer programming. In this paper we discuss an implementation of Dantzig et ..."
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Cited by 38 (6 self)
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Dantzig, Fulkerson, and Johnson (1954) introduced the cuttingplane method as a means of attacking the traveling salesman problem; this method has been applied to broad classes of problems in combinatorial optimization and integer programming. In this paper we discuss an implementation of Dantzig et al.'s method that is suitable for TSP instances having 1,000,000 or more cities. Our aim is to use the study of the TSP as a step towards understanding the applicability and limits of the general cuttingplane method in largescale applications.
Texture Mapping for Cel Animation
, 1998
"... We present a method for applying complex textures to handdrawn characters in cel animation. The method correlates features in a simple, textured, 3D model with features on a handdrawn figure, and then distorts the model to conform to the handdrawn artwork. The process uses two new algorithms: a ..."
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Cited by 34 (4 self)
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We present a method for applying complex textures to handdrawn characters in cel animation. The method correlates features in a simple, textured, 3D model with features on a handdrawn figure, and then distorts the model to conform to the handdrawn artwork. The process uses two new algorithms: a silhouette detection scheme and a depthpreserving warp. The silhouette detection algorithm is simple and efficient, and it produces continuous, smooth, visible contours on a 3D model. The warp distorts the model in only two dimensions to match the artwork from a given camera perspective, yet preserves 3D effects such as selfocclusion and foreshortening. The entire process allows animators to combine complex textures with handdrawn artwork, leveraging the strengths of 3D computer graphics while retaining the expressiveness of traditional handdrawn cel animation.
Optimal UnionFind in Constraint Handling Rules
 THEORY AND PRACTICE OF LOGIC PROGRAMMING
, 2006
"... Constraint Handling Rules (CHR) is a committedchoice rulebased language that was originally intended for writing constraint solvers. In this paper we show that it is also possible to write the classic unionfind algorithm and variants in CHR. The programs neither compromise in declarativeness nor ..."
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Cited by 34 (25 self)
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Constraint Handling Rules (CHR) is a committedchoice rulebased language that was originally intended for writing constraint solvers. In this paper we show that it is also possible to write the classic unionfind algorithm and variants in CHR. The programs neither compromise in declarativeness nor e#ciency. We study the time complexity of our programs: they match the almostlinear complexity of the best known imperative implementations. This fact is illustrated with experimental results.