Sökning: "Knot theory"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden Knot theory.

  1. 1. Invariants of knot diagrams and diagrammatic knot invariants

    Författare :Olof-Petter Östlund; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Knot theory; knot diagram; plane curve; Reidemeister move; finite degree invariant; combinatorial knot invariant; Gauss diagram; MATEMATIK; MATHEMATICS; MATEMATIK; matematik; Mathematics;

    Sammanfattning : Two knot diagrams describe isotopic knots if and only if they can be connected by a sequence of planar isotopies and Reidemeister moves (cusp-, self-tangency-, and triple point moves). In this dissertation classes of knot diagrams, Reidemeister moves, and relations between sequences of Reidemeister moves are investigated, in a manner inspired by V. LÄS MER

  3. 2. Modeling the effects of knots in Structural Timber

    Författare :Christina Foley; Avdelningen för Konstruktionsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material technology; Byggnadsteknik; Building construction; three-dimensional fiber paradigm; fiber deviation; knots; annual growth layer; material matrix; knot bump; structural timber; load carrying capacity; Materiallära; critical knot; knot distance ratio; local principal material directions; stiffness; materialteknik;

    Sammanfattning : The main purpose of the pursued research is to increase knowledge of the effects of knots in structural timber so that characteristics of weaker timber may be determined and applied to improve current grading techniques. In the process, a three-dimensional fiber paradigm was established, which describes variations of local principle material axes in timber containing knots. LÄS MER

  4. 3. Field Theories and Vortices with Nontrivial Geometry

    Författare :Kristel Torokoff; Antti Niemi; Masud Chaichian; Uppsala universitet; []
    Nyckelord :Theoretical physics; theoretical physics; gauge field theory; knot theory; spontaneously broken symmetry; effective model; numerical calculation; soliton; vortex; electromagnetic plasma; Teoretisk fysik;

    Sammanfattning : This thesis investigates aspects of field theories and soliton solutions with nontrivial topology. In particular we explore the following effective models: a limited sector of the scalar Electroweak theory called extended Abelian Higgs model, and a classical mechanics model derived from the low energy SU(2) Yang-Mills theory. LÄS MER

  5. 4. Bayesian Modeling of Conditional Densities

    Författare :Feng Li; Mattias Villani; Sylvia Frühwirth-Schnatter; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bayesian inference; Density estimation; smooth mixtures; surface regression; copulas; Markov chain Monte Carlo; Statistics; statistik;

    Sammanfattning : This thesis develops models and associated Bayesian inference methods for flexible univariate and multivariate conditional density estimation. The models are flexible in the sense that they can capture widely differing shapes of the data. The estimation methods are specifically designed to achieve flexibility while still avoiding overfitting. LÄS MER

  7. 5. Topological excitations in field theory models of superconductivity and magnetism

    Författare :Philipp Rybakov; Egor Babaev; Maxim Mostovoy; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics; Teoretisk fysik; Theoretical Physics;

    Sammanfattning : Topological excitations are subjects of intensive studies in physics and mathematics. In solid-state and soft matter physics, topological excitations can largely determine the thermodynamic and electromagnetic properties of materials, while in high energy physics they were theorized as particles. LÄS MER