Download or read book Constraint Satisfaction Problems and Friends written by Akbar Rafiey and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Constraint Satisfaction Problem (CSP) provides a general framework for a wide range of combinatorial problems dealing with mappings and assignments, including satisfiability, graph colorability, and systems of equations. Followed by seminal work of Feder and Vardi 1993, universal algebraic techniques have been developed and quite successfully employed in studies of CSPs from different perspectives. In this dissertation, we consider two significant generalizations of CSPs, namely the Ideal Membership Problem (IMP) and Valued CSP (VCSP), and study them through the lens of universal algebra.IMP is a fundamental algorithmic problem in which we are given a real polynomial f and an ideal I and the question is to decide whether f belongs to the ideal I. We consider a systematic study of IMPs arising from CSPs where the type of constraints is limited to relations from a constraint language. We show that many CSP techniques can be translated to IMPs thus allowing us to significantly improve the methods of studying the complexity of the IMP. We also develop universal algebraic techniques for the IMP that have been so useful in the study of the CSP. This allows us to prove a general necessary condition for the tractability of the IMP, and several sufficient ones. We furthermore introduce a variant of the IMP and study its complexity. We prove several algorithmic consequences of it such as a unifying framework to design polynomial-time algorithm to construct Groebner basis for many combinatorial problems. Finally, we study applications of our results in automatability of Sum-of-Squares (SoS) proofs and construction of Theta Bodies of combinatorial problems. We then turn our attention to the most general optimization variant of the CSP namely, Valued Constraint Satisfaction Problem (VCSP), which deals with both feasibility and optimization. We consider the Minimum Cost H-coloring problem which is an important type of VCSP and is a natural optimization version of the classical H-coloring problem. We give a complete classification of graphs, in terms of their polymorphisms, for which the Minimum Cost H-coloring is approximable within a constant factor, and present several positive results regarding digraphs. From a more practical point of view, VCSPs are at the core of many machine learning and data mining tasks and in numerous number of such applications the underlying VCSPs satisfy the submodularity property. We study central topics in machine learning, namely differential privacy and sparsification, in the context of submodularity, and present several algorithmic results.

Download or read book Exact Algorithms for Constraint Satisfaction Problems written by Robin Alexander Moser and published by Logos Verlag Berlin GmbH. This book was released on 2013 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Boolean satisfiability problem (SAT) and its generalization to variables of higher arities - constraint satisfaction problems (CSP) - can arguably be called the most "natural" of all NP-complete problems. The present work is concerned with their algorithmic treatment. It consists of two parts. The first part investigates CSPs for which satisfiability follows from the famous Lovasz Local Lemma. Since its discovery in 1975 by Paul Erdos and Laszlo Lovasz, it has been known that CSPs without dense spots of interdependent constraints always admit a satisfying assignment. However, an iterative procedure to discover such an assignment was not available. We refine earlier attempts at making the Local Lemma algorithmic and present a polynomial time algorithm which is able to make almost all known applications constructive. In the second part, we leave behind the class of polynomial time tractable problems and instead investigate the randomized exponential time algorithm devised and analyzed by Uwe Schoning in 1999, which solves arbitrary clause satisfaction problems. Besides some new interesting perspectives on the algorithm, the main contribution of this part consists of a refinement of earlier approaches at derandomizing Schoning's algorithm. We present a deterministic variant which losslessly reaches the performance of the randomized original.

Download or read book Bridging Constraint Satisfaction and Boolean Satisfiability written by Justyna Petke and published by Springer. This book was released on 2015-08-25 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a significant step towards bridging the areas of Boolean satisfiability and constraint satisfaction by answering the question why SAT-solvers are efficient on certain classes of CSP instances which are hard to solve for standard constraint solvers. The author also gives theoretical reasons for choosing a particular SAT encoding for several important classes of CSP instances. Boolean satisfiability and constraint satisfaction emerged independently as new fields of computer science, and different solving techniques have become standard for problem solving in the two areas. Even though any propositional formula (SAT) can be viewed as an instance of the general constraint satisfaction problem (CSP), the implications of this connection have only been studied in the last few years. The book will be useful for researchers and graduate students in artificial intelligence and theoretical computer science.

Download or read book Constraint Based Agents written by Alexander Nareyek and published by Springer. This book was released on 2003-06-29 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous agents have become a vibrant research and development topic in recent years attracting activity and attention from various areas. The basic agent concept incorporates proactive autonomous units with goal-directed-behaviour and communication capabilities. The book focuses on autonomous agents that can act in a goal directed manner under real time constraints and incomplete knowledge, being situated in a dynamic environment where resources may be restricted. To satisfy such complex requirements, the author improves, combines, and applies results from areas like planning, constraint programming, and local search. The formal framework developed is evaluated by application to the field of computer games, which fit the problem context very well since most of them are played in real time and provide a highly interactive environment where environmental situations are changing rapidly.

Download or read book Algorithms and Complexity of Constraint Satisfaction Problems written by Marko Samer and published by . This book was released on 2009 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Constraint Satisfaction Techniques for Agent Based Reasoning written by Nicoleta Neagu and published by Springer Science & Business Media. This book was released on 2006-03-30 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constraint satisfaction problems are significant in the domain of automated reasoning for artificial intelligence. They can be applied to the modeling and solving of a wide range of combinatorial applications such as planning, scheduling and resource sharing in a variety of practical domains such as transportation, production, supply-chains, network management and human resource management. In this book we study new techniques for solving constraint satisfaction problems, with a special focus on solution adaptation applied to agent reasoning.

Download or read book The Complexity of Valued Constraint Satisfaction Problems written by Springer and published by . This book was released on 2012-10-20 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Constraint Programming and Large Scale Discrete Optimization written by Eugene C. Freuder and published by American Mathematical Soc.. This book was released on 2001 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the September 1998 workshop deals with the application of constraint programming to problems of combinatorial optimization and industrial practice, covering general techniques, scheduling problems, and software methodology. The eight papers discuss using global constraints for local search, multithreaded constraint programming, employee scheduling, mission scheduling on orbiting satellites, sports scheduling, and the main results of the CHIC-2 project on large scale constraint optimization. No index. c. Book News Inc.

Download or read book Decision Theory and Multi Agent Planning written by Giacomo Della Riccia and published by Springer Science & Business Media. This book was released on 2007-05-03 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presents a modern, unified view on decision support and planning by considering its basics like preferences, belief, possibility and probability as well as utilities. These features together are immanent for software agents to believe the user that the agents are "intelligent".

Download or read book Communication Based Systems written by Günter Hommel and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 3rd International Workshop held at the TU Berlin, Germany, 31 March-1 April 2000

Download or read book Constraint Processing written by Rina Dechter and published by Morgan Kaufmann. This book was released on 2003-05-05 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constraint reasoning has matured over the last three decades with contributions from a diverse community of researchers in artificial intelligence, databases and programming languages, operations research, management science, and applied mathematics. In Constraint Processing, Rina Dechter synthesizes these contributions, as well as her own significant work, to provide the first comprehensive examination of the theory that underlies constraint processing algorithms.

Download or read book Applications of Partial Polymorphisms in Fine Grained Complexity of Constraint Satisfaction Problems written by Biman Roy and published by Linköping University Electronic Press. This book was released on 2020-03-23 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Extending Constraint Satisfaction Problems with Value Constraints written by I. Eidhammer and published by . This book was released on 1993 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Advances in Constraints written by Barry O'Sullivan and published by Springer. This book was released on 2003-08-03 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed post-proceedings of the Joint ERCIM/CologNet International Workshop on Constraint Solving and Constraint Logic Programming, held in Cork, Ireland in June 2002. The 14 revised full papers presented were carefully selected for inclusion in the book during two rounds of reviewing and revision. Among the topics addressed are verification and debugging of constraint logic programs, modeling and solving CSPs, explanation generation, inference and inconsistency processing, SAT and 0/1 encodings of CSPs, soft constraints and constraint relaxation, real-world applications, and distributed constraint solving.

Download or read book Solving Distributed Constraint Satisfaction Problems written by Qiangyi Luo and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Constraint Satisfaction Problems and Related Logic written by Florent Madelaine and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two Approaches to the Hierarchical Solution of Constraint Satisfaction Problems written by Sunil Kumar Mohan and published by . This book was released on 1996 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: