constraintprogramming has proven to be a successful framework for determining whether a given instance of the three-dimensional stable matching problem with cyclic preferences (3dsm-cyc) admits a solution. If such an...
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constraintprogramming is known for being an efficient approach to solving combinatorial problems. Important design choices in a solver are the branching heuristics, designed to lead the search to the best solutions i...
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Model-based decision support systems rely on an explicit representation of some system whose dynamics is often qualitatively described by specifying the rates at which the system variables change. Such models are natu...
ISBN:
(纸本)3540666265
Model-based decision support systems rely on an explicit representation of some system whose dynamics is often qualitatively described by specifying the rates at which the system variables change. Such models are naturally represented as a set of ordinary differential equations (ODEs) which are parametric (they include parameters whose value is not known exactly). If safe decisions are to be made based on the values of these parameters, it is important to know them with sufficient precision.
Often, real-world constraint Satisfaction Problems (CSPs) are subject to uncertainty/dynamism not known in advance. Some techniques in the literature offer robust solutions for CSPs. Here, we analyze a previous exact/...
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the time required for a backtracking search procedure to solve a problem can be minimized by employing randomized restart procedures. To date, researchers designing restart policies have relied on the simplifying assu...
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In this paper, a method within the framework of propagation of interval constraints and based on the branch-and-bound optimization scheme for solving the job-shop scheduling problem will be presented. the goal is to p...
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Bound consistency can easily and efficiently be enforced on linear constraint. However, bound consistency techniques deal with every constraint separately. We show that in some cases much stronger bounds can be comput...
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Many combinatorial optimization problems do not have a clear structure, may present many side constraints, and may include subproblems. In addition, different instances within the same domain can have different struct...
ISBN:
(纸本)3540232419
Many combinatorial optimization problems do not have a clear structure, may present many side constraints, and may include subproblems. In addition, different instances within the same domain can have different structure and characteristics. As a consequence it is commonplace that a single algorithm is not the best performer on every problem instance. We consider an algorithm portfolio approach to try to help us select the best algorithm for a given problem instance. Our purpose is twofold: firstly, to show that structure at the instance level is tightly connected to algorithm performance, and secondly to demonstrate that different machine learning and modelling methodologies, specifically Decision Trees (DT), Case Based Reasoning (CBR) and Multinomial Logistic Regression (MLR), can be used to perform effective algorithm portfolio selection. We test our claims by applying the above mentioned techniques to a large set of instances of the Bid Evaluation Problem (BEP) in Combinatorial Auctions. A BEP consists of a Winner Determination Problem (a well-known NP-hard problem best solved by a IP-based approach), and additional temporal information and precedence constraints (which favour a CP-based approach). We solved the BEP instances using a set of different algorithms. We observed that two algorithms; one IP-based and the other a hybrid combining both CP and IP elements, outperformed all the others on all instances. Hence we divided the instances into 2 classes based on which of these 2 algorithms solves them best. In order to perform our analysis we extract a set of structure-based features, that are cheap to determine, from each instance . We apply the Machine Learning methodologies using the extracted features as input data and the best algorithms as prediction classes.
Proving that the state of a controlled nonlinear system always stays inside a time moving bubble (or capture tube) amounts to proving the inconsistency of a set of nonlinear inequalities in the time-state space. In pr...
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In CP, the most efficient model solving the TSP is the Weighted Circuit constraint (WCC) combined withthe k-cutset constraint. the WCC is mainly based on the edges cost of a given graph whereas the k-cutset constrain...
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