Sökning: "Constraint optimization"

Visar resultat 1 - 5 av 150 avhandlingar innehållade orden Constraint optimization.

  1. 1. Techniques for Efficient Constraint Propagation

    Författare :Mikael Zayenz Lagerkvist; Seif Haridi; Christian Schulte; Pierre Flener; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; constraint programming; constraint propagation; optimization; Computer science; Datalogi;

    Sammanfattning : This thesis explores three new techniques for increasing the efficiency of constraint propagation: support for incremental propagation, improved representation of constraints, and abstractions to simplify propagation.  Support for incremental propagation is added to a propagator centered propagation system by adding a new intermediate layer of abstraction, advisors, that capture the essential aspects of a variable centered system. LÄS MER

  3. 2. Label Cover Reductions for Unconditional Approximation Hardness of Constraint Satisfaction

    Författare :Cenny Wenner; Johan Håstad; Viggo Kann; Irit Dinur; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Combinatorial Optimization; Complexity Theory; Approximation; Approximability; Inapproximability; Computational Hardness; NP; Optimization; Constraint Satisfaction; Kombinatorisk optimering; Komplexitetsteori; Beräkningsteori; Approximation; Approximerbarhet; Beräkningssvårighet; NP; Optimering; Vilkorssatisfiering; Vilkorsuppfyllning; Vilkorstillfredställand; datalogi; Computer Science;

    Sammanfattning : Combinatorial optimization include such tasks as finding the quickest route to work, scheduling jobs to specialists, and placing bus stops so as to minimize commuter times. We consider problems where one is given a collection of constraints with the objective of finding an assignment satisfying as many constraints as possible, also known as Constraint Satisfaction Problems (CSPs). LÄS MER

  4. 3. On Some Combinatorial Optimization Problems : Algorithms and Complexity

    Författare :Hannes Uppman; Peter Jonsson; Christer Bäckström; Ulf Nilsson; Stanislav Živný; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computational complexity; optimization; constraint satisfaction problem;

    Sammanfattning : This thesis is about the computational complexity of several classes of combinatorial optimization problems, all related to the constraint satisfaction problems.A constraint language consists of a domain and a set of relations on the domain. For each such language there is a constraint satisfaction problem (CSP). LÄS MER

  5. 4. Approximation of topology optimization problems using sizing optimization problems

    Författare :Anton Evgrafov; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; structural optimization; bilevel programming; approximation; topology optimization; control in coefficients; optimal design; fictitious domain; control in coefficients;

    Sammanfattning : The present work is devoted to approximation techniques for singular extremal problems arising from optimal design problems in structural and fluid mechanics. The thesis consists of an introductory part and four independent papers, which however are united by the common idea of approximation and the related application areas. LÄS MER

  7. 5. Shape Optimization for Acoustic Wave Propagation Problems

    Författare :Rajitha Udawalpola; Martin Berggren; Pekka Neittaanmäki; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shape optimization; design optimization; acoustic wave propagation; Helmholtz equation; Boundary Element Method; Finite Element Method; inverse problems; adjoint method; gradient-based optimization; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Boundary shape optimization is a technique to search for an optimal shape by modifying the boundary of a device with a pre-specified topology. We consider boundary shape optimization of acoustic horns in loudspeakers and brass wind instruments. LÄS MER