Search for dissertations about: "discrete variables"

Showing result 1 - 5 of 92 swedish dissertations containing the words discrete variables.

  2. 1. Studies in Efficient Discrete Algorithms

    Author : DZMITRY SLEDNEU; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Algorithms; Approximation algorithms; Graphs;

    Abstract : This thesis consists of five papers within the design and analysis of efficient algorithms.In the first paper, we consider the problem of computing all-pairs shortest paths in a directed graph with real weights assigned to vertices. We develop a combinatorial randomized algorithm that runs in subcubic time for a special class of graphs. READ MORE

  4. 2. On random satisfiability and optimization problems

    Author : Joel Larsson; Klas Markström; Roland Häggkvist; Victor Falgas Ravry; Stefanie Gerke; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Random graphs; k-SAT; satisfiability; coupon collector; random cover time; threshold phenomenon; concentration of measure; combinatorial probability; perfect matching; assignment problem; local graph limit; mean-field; Mathematics; matematik;

    Abstract : In Paper I, we study the following optimization problem: in the complete bipartite graph where edges are given i.i.d. weights of pseudo-dimension q>0, find a perfect matching with minimal total weight. READ MORE

  5. 3. Combinatorics and zeros of multivariate polynomials

    Author : Nima Amini; Petter Bränden; Jim Haglund; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Abstract : This thesis consists of five papers in algebraic and enumerative combinatorics. The objects at the heart of the thesis are combinatorial polynomials in one or more variables. We study their zeros, coefficients and special evaluations. Hyperbolic polynomials may be viewed as multivariate generalizations of real-rooted polynomials in one variable. READ MORE

  6. 4. Around power ideals : From Fröberg's conjecture to zonotopal algebra

    Author : Gleb Nenashev; Boris Shapiro; Volkmar Welker; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Mathematics; matematik;

    Abstract : In this thesis we study power algebras, which are quotient of polynomial rings by power ideals. We will study Hilbert series of such ideals and their other properties. We consider two important special cases, namely, zonotopal ideals and generic ideals. Such ideals have a lot combinatorial properties. READ MORE

  7. 5. Admissible transformations and the group classification of Schrödinger equations

    Author : Celestin Kurujyibwami; Peter Basarab-Horwath; Roman Popovych; Pontelis Damianou; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : We study admissible transformations and solve group classification problems for various classes of linear and nonlinear Schrödinger equations with an arbitrary number n of space variables.The aim of the thesis is twofold. READ MORE