Sökning: "Klas Markström"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Klas Markström.

  1. 1. On random cover and matching problems

    Författare :Joel Larsson; Klas Markström; Tatyana Turova; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; matematik;

    Sammanfattning : This thesis consists of the following papers.I  J. Larsson, The Minimum Matching in Pseudo-dimension 0 < q < 1, submittedII  V. Falgas-Ravry, J. LÄS MER

  3. 2. Building and Destroying Urns, Graphs, and Trees

    Författare :Fabian Burghart; Cecilia Holmgren; Svante Janson; Klas Markström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In this thesis, consisting of an introduction and four papers, different models in the mathematical area of combinatorial probability are investigated.In Paper I, two operations for combining generalised Pólya urns, called disjoint union and product, are defined. LÄS MER

  4. 3. Snarks : Generation, coverings and colourings

    Författare :Jonas Hägglund; Roland Häggkvist; Klas Markström; Luis Goddyn; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Snarks; cubic graphs; enumeration; cycle covers; perfect matching covers; Fulkerson s conjecture; strong cycle double cover conjecture; cycle decompositions; stable cycles; oddness; circumference; uncolourability measures; Mathematics; matematik;

    Sammanfattning : For a number of unsolved problems in graph theory such as the cycle double cover conjecture, Fulkerson's conjecture and Tutte's 5-flow conjecture it is sufficient to prove them for a family of graphs called snarks. Named after the mysterious creature in Lewis Carroll's poem, a \emph{snark} is a cyclically 4-edge connected 3-regular graph of girth at least 5 which cannot be properly edge coloured using three colours. LÄS MER

  5. 4. On minimal triangle-free Ramsey graphs

    Författare :Oliver Krüger; Jörgen Backelin; Klas Markström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : A graph G is called a minimal Ramsey (3, k; n)-graph if it has the least amount of edges, e(3, k; n), possible given that G is triangle-free, has independence number α(G) < k an has n vertices. The numbers e(3, k; n) and the minimalRamsey graphs are directly related to the Ramsey numbers R(3, k). LÄS MER

  7. 5. On random satisfiability and optimization problems

    Författare :Joel Larsson; Klas Markström; Roland Häggkvist; Victor Falgas Ravry; Stefanie Gerke; Umeå universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER