Complexity of Constraints

Complexity of Constraints PDF Author: Nadia Creignou
Publisher: Springer Science & Business Media
ISBN: 3540927999
Category : Computers
Languages : en
Pages : 326

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Book Description
Nowadays constraint satisfaction problems (CSPs) are ubiquitous in many different areas of computer science, from artificial intelligence and database systems to circuit design, network optimization, and theory of programming languages. Consequently, it is important to analyze and pinpoint the computational complexity of certain algorithmic tasks related to constraint satisfaction. The complexity-theoretic results of these tasks may have a direct impact on, for instance, the design and processing of database query languages, or strategies in data-mining, or the design and implementation of planners. This state-of-the-art survey contains the papers that were invited by the organizers after conclusion of an International Dagstuhl-Seminar on Complexity of Constraints, held in Dagstuhl Castle, Germany, in October 2006. A number of speakers were solicited to write surveys presenting the state of the art in their area of expertise. These contributions were peer-reviewed by experts in the field and revised before they were collated to the 9 papers of this volume. In addition, the volume contains a reprint of a survey by Kolaitis and Vardi on the logical approach to constraint satisfaction that first appeared in 'Finite Model Theory and its Applications', published by Springer in 2007.

Complexity of Constraints

Complexity of Constraints PDF Author: Nadia Creignou
Publisher: Springer Science & Business Media
ISBN: 3540927999
Category : Computers
Languages : en
Pages : 326

Get Book

Book Description
Nowadays constraint satisfaction problems (CSPs) are ubiquitous in many different areas of computer science, from artificial intelligence and database systems to circuit design, network optimization, and theory of programming languages. Consequently, it is important to analyze and pinpoint the computational complexity of certain algorithmic tasks related to constraint satisfaction. The complexity-theoretic results of these tasks may have a direct impact on, for instance, the design and processing of database query languages, or strategies in data-mining, or the design and implementation of planners. This state-of-the-art survey contains the papers that were invited by the organizers after conclusion of an International Dagstuhl-Seminar on Complexity of Constraints, held in Dagstuhl Castle, Germany, in October 2006. A number of speakers were solicited to write surveys presenting the state of the art in their area of expertise. These contributions were peer-reviewed by experts in the field and revised before they were collated to the 9 papers of this volume. In addition, the volume contains a reprint of a survey by Kolaitis and Vardi on the logical approach to constraint satisfaction that first appeared in 'Finite Model Theory and its Applications', published by Springer in 2007.

Complexity of Constraints

Complexity of Constraints PDF Author: Nadia Creignou
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Complexity Classifications of Boolean Constraint Satisfaction Problems

Complexity Classifications of Boolean Constraint Satisfaction Problems PDF Author: Nadia Creignou
Publisher: SIAM
ISBN: 0898714796
Category : Mathematics
Languages : en
Pages : 112

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Book Description
Presents a novel form of a compendium that classifies an infinite number of problems by using a rule-based approach.

Complexity in Numerical Optimization

Complexity in Numerical Optimization PDF Author: Panos M. Pardalos
Publisher: World Scientific
ISBN: 9789810214159
Category : Mathematics
Languages : en
Pages : 536

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Book Description
Computational complexity, originated from the interactions between computer science and numerical optimization, is one of the major theories that have revolutionized the approach to solving optimization problems and to analyzing their intrinsic difficulty.The main focus of complexity is the study of whether existing algorithms are efficient for the solution of problems, and which problems are likely to be tractable.The quest for developing efficient algorithms leads also to elegant general approaches for solving optimization problems, and reveals surprising connections among problems and their solutions.This book is a collection of articles on recent complexity developments in numerical optimization. The topics covered include complexity of approximation algorithms, new polynomial time algorithms for convex quadratic minimization, interior point algorithms, complexity issues regarding test generation of NP-hard problems, complexity of scheduling problems, min-max, fractional combinatorial optimization, fixed point computations and network flow problems.The collection of articles provide a broad spectrum of the direction in which research is going and help to elucidate the nature of computational complexity in optimization. The book will be a valuable source of information to faculty, students and researchers in numerical optimization and related areas.

Constraints on Language Variation and Change in Complex Multilingual Contact Settings

Constraints on Language Variation and Change in Complex Multilingual Contact Settings PDF Author: Bertus van Rooy
Publisher: John Benjamins Publishing Company
ISBN: 9027246963
Category : Language Arts & Disciplines
Languages : en
Pages : 301

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Book Description
Constraints on Language Variation and Change in Complex Multilingual Contact Settings explores an innovative proposal: that linguistic similarities identified in different forms of contact-influenced varieties of language use (including translation, native and non-native varieties of English, and language use of bilinguals more generally) can be accounted for in a coherent framework grounded in the notion of ‘constrained communication’. These varieties have hitherto been studied in independent scholarly traditions, especially translation studies and world Englishes, leaving the potential underlying unity underexplored, both conceptually and empirically. The chapters collected in this volume aim to develop such a unified perspective by drawing on corpus data across a range of languages and language varieties, with a focus on written language, a neglected data source in research on multilingual contact settings. The findings point to shared general characteristics across individual contact settings, which result from (probabilistically conditioned) manifestations of the same deeper regularities – constraints – present in diverse language-contact settings.

Recent Advances in Constraints

Recent Advances in Constraints PDF Author: Brahim Hnich
Publisher: Springer Science & Business Media
ISBN: 354034215X
Category : Business & Economics
Languages : en
Pages : 187

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Book Description
This book constitutes the thoroughly refereed and extended post-proceedings of the Joint ERCIM/CoLogNet International Workshop on Constraint Solving and Constraint Logic Programming, CSCLP 2005. The 12 revised full papers presented were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on global constraints, search and heuristics, language and implementation issues, and modeling.

Complexity of Infinite-Domain Constraint Satisfaction

Complexity of Infinite-Domain Constraint Satisfaction PDF Author: Manuel Bodirsky
Publisher: Cambridge University Press
ISBN: 1107042844
Category : Computers
Languages : en
Pages : 537

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Book Description
Introduces the universal-algebraic approach to classifying the computational complexity of constraint satisfaction problems.

Applications of Partial Polymorphisms in (Fine-Grained) Complexity of Constraint Satisfaction Problems

Applications of Partial Polymorphisms in (Fine-Grained) Complexity of Constraint Satisfaction Problems PDF Author: Biman Roy
Publisher: Linköping University Electronic Press
ISBN: 9179298982
Category :
Languages : en
Pages : 57

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Book Description
In this thesis we study the worst-case complexity ofconstraint satisfaction problems and some of its variants. We use methods from universal algebra: in particular, algebras of total functions and partial functions that are respectively known as clones and strong partial clones. The constraint satisfactionproblem parameterized by a set of relations ? (CSP(?)) is the following problem: given a set of variables restricted by a set of constraints based on the relations ?, is there an assignment to thevariables that satisfies all constraints? We refer to the set ? as aconstraint language. The inverse CSPproblem over ? (Inv-CSP(?)) asks the opposite: given a relation R, does there exist a CSP(?) instance with R as its set of models? When ? is a Boolean language, then we use the term SAT(?) instead of CSP(?) and Inv-SAT(?) instead of Inv-CSP(?). Fine-grained complexity is an approach in which we zoom inside a complexity class and classify theproblems in it based on their worst-case time complexities. We start by investigating the fine-grained complexity of NP-complete CSP(?) problems. An NP-complete CSP(?) problem is said to be easier than an NP-complete CSP(?) problem if the worst-case time complexity of CSP(?) is not higher thanthe worst-case time complexity of CSP(?). We first analyze the NP-complete SAT problems that are easier than monotone 1-in-3-SAT (which can be represented by SAT(R) for a certain relation R), and find out that there exists a continuum of such problems. For this, we use the connection between constraint languages and strong partial clones and exploit the fact that CSP(?) is easier than CSP(?) when the strong partial clone corresponding to ? contains the strong partial clone of ?. An NP-complete CSP(?) problem is said to be the easiest with respect to a variable domain D if it is easier than any other NP-complete CSP(?) problem of that domain. We show that for every finite domain there exists an easiest NP-complete problem for the ultraconservative CSP(?) problems. An ultraconservative CSP(?) is a special class of CSP problems where the constraint language containsall unary relations. We additionally show that no NP-complete CSP(?) problem can be solved insub-exponential time (i.e. in2^o(n) time where n is the number of variables) given that theexponentialtime hypothesisis true. Moving to classical complexity, we show that for any Boolean constraint language ?, Inv-SAT(?) is either in P or it is coNP-complete. This is a generalization of an earlier dichotomy result, which was only known to be true for ultraconservative constraint languages. We show that Inv-SAT(?) is coNP-complete if and only if the clone corresponding to ? contains essentially unary functions only. For arbitrary finite domains our results are not conclusive, but we manage to prove that theinversek-coloring problem is coNP-complete for each k>2. We exploit weak bases to prove many of theseresults. A weak base of a clone C is a constraint language that corresponds to the largest strong partia clone that contains C. It is known that for many decision problems X(?) that are parameterized bya constraint language ?(such as Inv-SAT), there are strong connections between the complexity of X(?) and weak bases. This fact can be exploited to achieve general complexity results. The Boolean domain is well-suited for this approach since we have a fairly good understanding of Boolean weak bases. In the final result of this thesis, we investigate the relationships between the weak bases in the Boolean domain based on their strong partial clones and completely classify them according to the setinclusion. To avoid a tedious case analysis, we introduce a technique that allows us to discard a largenumber of cases from further investigation.

The Complexity of Sets Constraints

The Complexity of Sets Constraints PDF Author: Alexander Aiken
Publisher:
ISBN:
Category :
Languages : en
Pages : 58

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Book Description


Managing Business Complexity

Managing Business Complexity PDF Author: Michael J. North
Publisher: Oxford University Press
ISBN: 9780198038412
Category : Business & Economics
Languages : en
Pages : 328

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Book Description
Agent-based modeling and simulation (ABMS), a way to simulate a large number of choices by individual actors, is one of the most exciting practical developments in business modeling since the invention of relational databases. It represents a new way to understand data and generate information that has never been available before--a way for businesses to view the future and to understand and anticipate the likely effects of their decisions on their markets and industries. It thus promises to have far-reaching effects on the way that businesses in many areas use computers to support practical decision-making. Managing Business Complexity is the first complete business-oriented agent-based modeling and simulation resource. It has three purposes: first, to teach readers how to think about ABMS, that is, about agents and their interactions; second, to teach readers how to explain the features and advantages of ABMS to other people and third, to teach readers how to actually implement ABMS by building agent-based simulations. It is intended to be a complete ABMS resource, accessible to readers who haven't had any previous experience in building agent-based simulations, or any other kinds of models, for that matter. It is also a collection of ABMS business applications resources, all assembled in one place for the first time. In short, Managing Business Complexity addresses who needs ABMS and why, where and when ABMS can be applied to the everyday business problems that surround us, and how specifically to build these powerful agent-based models.