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13
VLSI cell placement techniques
 ACM Computing Surveys
, 1991
"... VLSI cell placement problem is known to be NP complete. A wide repertoire of heuristic algorithms exists in the literature for efficiently arranging the logic cells on a VLSI chip. The objective of this paper is to present a comprehensive survey of the various cell placement techniques, with emphasi ..."
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Cited by 76 (0 self)
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VLSI cell placement problem is known to be NP complete. A wide repertoire of heuristic algorithms exists in the literature for efficiently arranging the logic cells on a VLSI chip. The objective of this paper is to present a comprehensive survey of the various cell placement techniques, with emphasis on standard ce11and macro
The Complexity of Design Automation Problems
 Advanced Semiconductor Technology and Computer Systems
, 1980
"... This paper reviews several problems that arise in the area of design automation. Most of these problems are shown to be NPhard. Further, it is unlikely that any of these problems can be solved by fast approximation algorithms that guarantee solutions that are always within some fixed relative error ..."
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Cited by 13 (0 self)
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This paper reviews several problems that arise in the area of design automation. Most of these problems are shown to be NPhard. Further, it is unlikely that any of these problems can be solved by fast approximation algorithms that guarantee solutions that are always within some fixed relative error of the optimal solution value. This points out the importance of heuristics and other tools to obtain algorithms that perform well on the problem instances of interest.
A Stochastic Approach to the WeightedRegion Problem: Design and Testing of a Path Annealing Algorithm
, 1991
"... This paper presents an efficient heuristic algorithm for planning nearoptimal highlevel paths for a point agent moving through complex terrain modeled by the WeightedRegion Problem. The input to the WeightedRegion Problem is a set of nonoverlapping convex polygonal homogeneouscost regions on a ..."
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Cited by 7 (1 self)
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This paper presents an efficient heuristic algorithm for planning nearoptimal highlevel paths for a point agent moving through complex terrain modeled by the WeightedRegion Problem. The input to the WeightedRegion Problem is a set of nonoverlapping convex polygonal homogeneouscost regions on a twodimensional plane. Each region has an associated cost coefficient (or weight), for the cost per unit distance of movement in that region by a point agent. The objective is to find a minimumcost path through the weighted regions from a start point to a goal point. Our efficient algorithm combines heuristic search with probabilistic optimization by simulated annealing. It explores constrained random perturbations to the sequence of edges through which the path passes; then for each sequence, it solves a convex localoptimization subproblem to find the locallyoptimal path and its cost. Extensive test results indicate that the new algorithm runs much faster than previously known technique...
Reactive Search Optimization: Learning while Optimizing
"... The final purpose of Reactive Search Optimization (RSO) is to simplify the life for the final user of optimization. While researchers enjoy designing algorithms, testing alternatives, tuning parameters and choosing solution schemes — in fact this is part of their daily life — the final users ’ inter ..."
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Cited by 5 (2 self)
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The final purpose of Reactive Search Optimization (RSO) is to simplify the life for the final user of optimization. While researchers enjoy designing algorithms, testing alternatives, tuning parameters and choosing solution schemes — in fact this is part of their daily life — the final users ’ interests are different: solving a problem in the
Towards Optimal Circuit Layout Using Advanced Search Techniques
 University of Waterloo
, 1995
"... I hereby declare that I am the sole author of this thesis. I authorize the University of Guelph to lend this thesis to other institutions or individuals for the purpose of scholarly research. I further authorize the University of Guelph to reproduce this thesis by photocopying or by other means, in ..."
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Cited by 5 (1 self)
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I hereby declare that I am the sole author of this thesis. I authorize the University of Guelph to lend this thesis to other institutions or individuals for the purpose of scholarly research. I further authorize the University of Guelph to reproduce this thesis by photocopying or by other means, in total or in part, at the request of other institutions or individuals for the purpose of scholarly research. ii The University of Guelph requires the signatures of all persons using or photocopying this thesis. Please sign below, and give address and date. iii iv A VLSI chip can today contain millions of transistors and is expected to contain more than 100 million transistors in the next decade. This tremendous growth is made possible by the development of sophisticated design tools and software. To deal with the complexity
Towards Optimal Storage Design for Efficient Query Processing in Relational Database Systems
, 1995
"... The placement of records, and the methods used to access them, can significantly affect the performance of query processing in a database management system. By making use of information about query patterns and their frequencies, we aim to design file organisations which optimally cluster records th ..."
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Cited by 5 (1 self)
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The placement of records, and the methods used to access them, can significantly affect the performance of query processing in a database management system. By making use of information about query patterns and their frequencies, we aim to design file organisations which optimally cluster records through the use of indexes. Many different record indexing techniques can be used to cluster records. Multiattribute hash indexing is the indexing technique which we use to demonstrate the effectiveness of our proposals. We describe algorithms which exploit a clustering arrangement for range queries, join queries and other relational queries, and describe the costs of these algorithms. We compare the performance of various optimisation techniques for the problem of optimally clustering records using each of these algorithms. In general, designing optimal indexes to cluster records is NPhard. We show that by combining heuristic and combinatorial algorithms, nearoptimal indexes can be constru...
Optimal Storage Management of Relations for Join Operations
, 1992
"... In this paper we describe a general solution to the problem of optimal clustering of relations for a file which is to answer queries involving the join operation implemented using either the sortmerge or hashjoin algorithms. This technique is extended to optimal clustering of relations when there ..."
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Cited by 1 (1 self)
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In this paper we describe a general solution to the problem of optimal clustering of relations for a file which is to answer queries involving the join operation implemented using either the sortmerge or hashjoin algorithms. This technique is extended to optimal clustering of relations when there are constraints on the domain size. In this paper we use the multiattribute hashing technique as an indexing scheme to which our solution applies. Partially supported by an APRA scholarship. y Partially supported by a CRC/CIDS grant. 1 Introduction. Much work has been done in constructing schemes to cluster relations which optimise the performance of partial match queries. Determining the optimal clustering arrangement to minimise the average cost of a query is an area of research which has received some attention, primarily when the multiattribute hashing indexing method is used. Examples of this may be found in [1, 14, 17, 21]. However, this form of retrieval is only one of the r...
Genetic Selection of Parametric Scenes Genetic Algorithms
, 2003
"... We look at a possible alternative to designing parametric scenes through a traditional method by using a Genetic Selection of specific scenes in order to “evolve ” a solution which is acceptable to the user. We also show ..."
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We look at a possible alternative to designing parametric scenes through a traditional method by using a Genetic Selection of specific scenes in order to “evolve ” a solution which is acceptable to the user. We also show
Metaheuristics and Combinatorial Optimization Problems
"... The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. iii Scriptor, Gerald Skidmore (M.S., C.S.) Metaheuristics and Combinatorial Optimization Prob ..."
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The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. iii Scriptor, Gerald Skidmore (M.S., C.S.) Metaheuristics and Combinatorial Optimization Problems Thesis directed by Professor Peter Anderson This thesis will use the traveling salesman problem (TSP) as a tool to help present and investigate several new techniques that improve the overall performance of genetic algorithms (GA). Improvements include a new parent selection algorithm, harem select, that outperforms all other parent selection algorithms tested, some by up to 600%. Other techniques investigated include population seeding, random restart, heuristic crossovers, and hybrid genetic algorithms, all of which posted improvements in the range of 1 % up to 1100%. Also studied will be a new algorithm, GRASP, that is just starting to enjoy a lot of interest in the research community and will also been applied to the traveling salesman problem (TSP). Given very little time to run, relative to other popular metaheuristic algorithms, GRASP was
Solving a Set Covering Problem with Genetic Algorithms
"... In this paper we describe the various stochastic algorithms for combinatorial optimization and then discuss the implementation of a genetic algorithm for solving a set covering problem which arises in the design of an error detection circuit using a linear output space compression method. 1. Set Cov ..."
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In this paper we describe the various stochastic algorithms for combinatorial optimization and then discuss the implementation of a genetic algorithm for solving a set covering problem which arises in the design of an error detection circuit using a linear output space compression method. 1. Set Covering Problem Problem Statement. The setcovering problem (SCP) is one of the classical problems of combinatorial optimization. It may be stated as follows: If F = f' 1 ; ' 2 ; : : : ; 'ng is a (finite) set and M ae P(F ) (where P(F ) denotes the power set of the set F ), then SCP consists of finding the subset C of M such that 8i; ' i 2 [ M2C M; and X M2C c M ! min; where c M is a (positive) cost value associated with each of the sets M 2 M. If all the cost values are 1, we have the unicost SCP. The SCP problem can be represented by a matrix whose rows are indexed by the elements and columns by the sets. The element in the place (i; j) of the matrix is equal to 1 if ' i 2 M j and...