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59
Expander Codes
 IEEE Transactions on Information Theory
, 1996
"... We present a new class of asymptotically good, linear errorcorrecting codes based upon expander graphs. These codes have linear time sequential decoding algorithms, logarithmic time parallel decoding algorithms with a linear number of processors, and are simple to understand. We present both random ..."
Abstract

Cited by 280 (10 self)
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We present a new class of asymptotically good, linear errorcorrecting codes based upon expander graphs. These codes have linear time sequential decoding algorithms, logarithmic time parallel decoding algorithms with a linear number of processors, and are simple to understand. We present both randomized and explicit constructions for some of these codes. Experimental results demonstrate the extremely good performance of the randomly chosen codes. 1. Introduction We present a new class of error correcting codes derived from expander graphs. These codes have the advantage that they can be decoded very efficiently. That makes them particularly suitable for devices which must decode cheaply, such as compact disk players and remote satellite receivers. We hope that the connection we draw between expander graphs and error correcting codes will stimulate research in both fields. 1.1. Error correcting codes An error correcting code is a mapping from messages to codewords such that the mappi...
Reasoning about Qualitative Temporal Information
 Artificial Intelligence
, 1992
"... Representing and reasoning about incomplete and indefinite qualitative temporal information is an essential part of many artificial intelligence tasks. An intervalbased framework and a pointbased framework have been proposed for representing such temporal information. In this paper, we address ..."
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Cited by 137 (5 self)
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Representing and reasoning about incomplete and indefinite qualitative temporal information is an essential part of many artificial intelligence tasks. An intervalbased framework and a pointbased framework have been proposed for representing such temporal information. In this paper, we address two fundamental reasoning tasks that arise in applications of these frameworks: Given possibly indefinite and incomplete knowledge of the relationships between some intervals or points, (i) find a scenario that is consistent with the information provided, and (ii) find the feasible relations between all pairs of intervals or points. For the pointbased framework and a restricted version of the intervalbased framework, we give computationally efficient procedures for finding a consistent scenario and for finding the feasible relations. Our algorithms are marked improvements over the previously known algorithms. In particular, we develop an O(n 2 ) time algorithm for finding one co...
Lineartime Encodable and Decodable ErrorCorrecting Codes
, 1996
"... We present a new class of asymptotically good, linear errorcorrecting codes. These codes can be both encoded and decoded in linear time. They can also be encoded by logarithmicdepth circuits of linear size and decoded by logarithmic depth circuits of size 0 (n log n). We present both randomized an ..."
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Cited by 118 (5 self)
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We present a new class of asymptotically good, linear errorcorrecting codes. These codes can be both encoded and decoded in linear time. They can also be encoded by logarithmicdepth circuits of linear size and decoded by logarithmic depth circuits of size 0 (n log n). We present both randomized and explicit constructions of these codes.
Transducers and repetitions
 Theoretical Computer Science
, 1986
"... Abstract. The factor transducer of a word associates to each of its factors (or subwc~rds) their first occurrence. Optimal bounds on the size of minimal factor transducers together with an algorithm for building them are given. Analogue results and a simple algorithm are given for the case of subseq ..."
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Cited by 89 (17 self)
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Abstract. The factor transducer of a word associates to each of its factors (or subwc~rds) their first occurrence. Optimal bounds on the size of minimal factor transducers together with an algorithm for building them are given. Analogue results and a simple algorithm are given for the case of subsequential suffix transducers. Algorithms are applied to repetition searching in words. Rl~sum~. Le transducteur des facteurs d'un mot associe a chacun de ses facteurs leur premiere occurrence. On donne des bornes optimales sur la taille du transducteur minimal d'un mot ainsi qu'un algorithme pour sa construction. On donne des r6sultats analogues et un algorithme simple dans le cas du transducteur souss~luentiel des suffixes d'un mot. On donne une application la d6tection de r6p6titions dans les mots. Contents
On the Complexity of Sphere Decoding in Digital Communications
 IN DIGITAL COMMUNICATIONS,” IEEE TRANSACTIONS ON SIGNAL PROCESSING, TO APPEAR
, 2005
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OnTheFly Detection of Access Anomalies
 In Proceedings of the SIGPLAN 1989 Conference on Programming Language Design and Implementation
, 1998
"... Access anomalies are a common class of bugs in sharedmemory parallel programs. An access anomaly occurs when two concurrent execution threads both write (or one thread reads and the other writes) the same shared memory location. Approaches to the detection of access anomalies include static analysi ..."
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Cited by 66 (0 self)
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Access anomalies are a common class of bugs in sharedmemory parallel programs. An access anomaly occurs when two concurrent execution threads both write (or one thread reads and the other writes) the same shared memory location. Approaches to the detection of access anomalies include static analysis, postmortem trace analysis, and onthe fly monitoring. A general onthefly algorithm for access anomaly detection is presented, which can be applied to programs with both nested forkjoin and synchronization operations. The advantage of onthefly detection over postmortem analysis is that the amount of storage used can be greatly reduced by data compression techniques and by discarding information as soon as it becomes obsolete. In the algorithm presented, the amount of storage required at any time depends only on the number V of shared variables being monitored and the number N of threads, not on the number of synchronizations. Data compression is achieved by the use of two techniques...
Curve reconstruction from unorganized points
 Computer Aided Geometric Design
, 2000
"... We present an algorithm to approximate a set of unorganized points with a simple curve without selfintersections. The moving leastsquares method has a good ability to reduce a point cloud to a thin curvelike shape which is a nearbest approximation of the point set. In this paper, an improved mov ..."
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Cited by 51 (3 self)
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We present an algorithm to approximate a set of unorganized points with a simple curve without selfintersections. The moving leastsquares method has a good ability to reduce a point cloud to a thin curvelike shape which is a nearbest approximation of the point set. In this paper, an improved moving leastsquares technique is suggested using Euclidean minimum spanning tree, region expansion and refining iteration. After thinning a given point cloud using the improved moving leastsquares technique we can easily reconstruct a smooth curve. As an application, a pipe surface reconstruction algorithm is presented.
New scaling algorithms for the assignment and minimum mean cycle problems
, 1992
"... In this paper we suggest new scaling algorithms for the assignment and minimum mean cycle problems. Our assignment algorithm is based on applying scaling to a hybrid version of the recent auction algorithm of Bertsekas and the successive shortest path algorithm. The algorithm proceeds by relaxing th ..."
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Cited by 48 (4 self)
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In this paper we suggest new scaling algorithms for the assignment and minimum mean cycle problems. Our assignment algorithm is based on applying scaling to a hybrid version of the recent auction algorithm of Bertsekas and the successive shortest path algorithm. The algorithm proceeds by relaxing the optimality conditions, and the amount of relaxation is successively reduced to zero. On a network with 2n nodes, m arcs, and integer arc costs bounded by C, the algorithm runs in O(,/n m log(nC)) time and uses very simple data structures. This time bound is comparable to the time taken by Gabow and Tarjan's scaling algorithm, and is better than all other time bounds under the similarity assumption, i.e., C = O(n k) for some k. We next consider the minimum mean cycle problem. The mean cost of a cycle is defined as the cost of the cycle divided by the number of arcs it contains. The minimum mean cycle problem is to identify a cycle whose mean cost is minimum. We show that by using ideas of the assignment algorithm in an approximate binary search procedure, the minimum mean cycle problem can also be solved in O(~/n m log nC) time. Under the similarity assumption, this is the best available time bound to solve the minimum mean cycle problem.