Sökning: "discrete geometry"

Visar resultat 1 - 5 av 65 avhandlingar innehållade orden discrete geometry.

  1. 1. Admissible transformations and the group classification of Schrödinger equations

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

    Sammanfattning : 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. LÄS MER

  3. 2. Vector-valued Eisenstein series of congruence types and their products

    Författare :Jiacheng Xia; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hecke operator; Fourier expansion of modular forms; congruence type; products of Eisenstein series; vector-valued modular forms;

    Sammanfattning : Historically, Kohnen and Zagier connected modular forms with period polynomials, and as a consequence of this association concluded that the products of at most two Eisenstein series span all spaces of classical modular forms of level 1. Later Borisov and Gunnells among other authors extended the result to higher levels. LÄS MER

  4. 3. Digital Geometry, Combinatorics, and Discrete Optimization

    Författare :Shiva Samieinia; Christer Kiselman; Rikard Bøgvad; Rémy Malgouyres; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Digital geometry; Khalimsky topology; Khalimsky plane; Khalimsky-continuous function; digital straight line segments; discrete optimization; discrete convexity; integral convexity; lateral convexity; marginal function; MATHEMATICS; MATEMATIK; Mathematics; matematik;

    Sammanfattning : This thesis consists of two parts: digital geometry and discrete optimization. In the first part we study the structure of digital straight line segments. We also study digital curves from a combinatorial point of view. LÄS MER

  5. 4. Topological and geometrical methods in data analysis

    Författare :Oliver Gäfvert; Sandra di Rocco; Henry Schenck; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; multiparameter persistent homology; computational algebraic geometry; algorithms; complexity; Mathematics; Matematik;

    Sammanfattning : This thesis concerns two related data analysis pipelines, using topological and geometrical methods respectively, to extract relevant information. The first pipeline, referred to as the topological data analysis (TDA) pipeline, constructs a filtered simplicial complex on a given data set in order to describe its shape. LÄS MER

  7. 5. Prestress and its application to shell, fabric, and cable net structures

    Författare :Alexander Sehlström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HUMANIORA; HUMANITIES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Geometric stiffness; Form finding; Conceptual design; Stress pattern; Engineering; Prestress; Architecture; Structuraldesign;

    Sammanfattning : Prestressing and shells provide means to create material-efficient and well-functioning structures, as do their combination, offering opportunities for increased material efficiency within the built environment. Prestressing introduces stresses in an object to enhance its performance, and shells include concrete shells, masonry vaults, fabric structures, cable nets, and timber or steel gridshells. LÄS MER