Sökning: "approximation problems"

Visar resultat 1 - 5 av 293 avhandlingar innehållade orden approximation problems.

1. 1. Approximation problems and weights

   Författare :Adem Limani; Matematik (naturvetenskapliga fakulteten); []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; approximation problems; weights; Spaces of analytic functions;

   Sammanfattning : This thesis is mainly concerned with investigations of approximation problems on spaces of analytic functions on the unit disc in the complex plane, which naturally arise in connection to spectral problems of certain classes of linear operators acting on the spaces in question. For instance, quasi-nilpotency of certain analytic paraproducts on the Hardy spaces and on the Bergman spaces are investigated. LÄS MER

3. 2. 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

4. 3. Spectral Moment Problems : Generalizations, Implementation and Tuning

   Författare :Enrico Avventi; Anders Lindquist; Giorgio Picci; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optimization; systems theory; Optimeringslära; systemteori;

   Sammanfattning : Spectral moment interpolation find application in a wide array of use cases: robust control, system identification, model reduction to name the most notable ones. This thesis aims to expand the theory of such methods in three different directions. The first main contribution concerns the practical applicability. LÄS MER

5. 4. Algorithmic Bounds for Presumably Hard Combinatorial Problems

   Författare :Andreas Björklund; Institutionen för datavetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; numerisk analys; system; control; Datalogi; numerical analysis; systems; Computer science; Approximation algorithms; Exact algorithms; NP-hard problems; Algorithm theory; kontroll;

   Sammanfattning : In this thesis we present new worst case computational bounds on algorithms for some of the most well-known NP-complete and #P-complete problems and their optimization variants. We consider graph problems like Longest Path, Maximum Cut, Number of Perfect Matchings, Chromatic and Domatic Number, as well as Maximum k-Satisfiability and Set Cover. LÄS MER

7. 5. 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