Sökning: "Natural Sciences Mathematics Geometry"

Visar resultat 16 - 20 av 243 avhandlingar innehållade orden Natural Sciences Mathematics Geometry.

1. 16. 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

3. 17. Geometry linking the art of building and the Universe: Geometric patterns on shells and grid shells

   Författare :Emil Adiels; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HUMANIORA; HUMANITIES; HUMANIORA; HUMANITIES; NATURVETENSKAP; NATURAL SCIENCES; Form finding; Differential Geometry; Conceptual design; Geometry; Shell; Engineering; Masonry; Craftsmanship; Grid shell; Architecture; Structural design;

   Sammanfattning : Geometry links the art of building and the physics of space-time. Mathematical breakthroughs in geometry have led to new ways of designing our structures and our ability to visualise and describe the world, phenomena in nature and the universe. LÄS MER

4. 18. The density of rational points and invariants of genus one curves

   Författare :Manh Hung Tran; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; genus one; discriminant; modular form; Elliptic curve; height; descent; determinantal representation; invariant; rational point; theta function.; determinant method;

   Sammanfattning : The present thesis contains three papers dealing with two arithmetic problems on curves of genus one, which are closely related to elliptic curves. The first problem is to study the density of rational points presented in Papers I and II. LÄS MER

5. 19. G-equivariant convolutional neural networks

   Författare :Jimmy Aronsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; deep learning; induced representations; homogeneous vector bundles; convolutional neural networks; homogeneous spaces; symmetry;

   Sammanfattning : Over the past decade, deep learning has revolutionized industry and academic research. Neural networks have been used to solve a multitude of previously unsolved problems and to significantly improve the state-of-the-art on other tasks, in some cases reaching superhuman levels of performance. LÄS MER

7. 20. Small energy isotopies of loose Legendrian submanifolds

   Författare :Lukas Nakamura; Tobias Ekholm; Álvaro del Pino Gómez; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; contact geometry; Legendrian submanifolds; Chekanov-Shelukhin-Hofer energy; Mathematics; Matematik;

   Sammanfattning : In the first paper, we prove that for a closed Legendrian submanifold L of dimension n>2 with a loose chart of size η, any Legendrian isotopy starting at L can be C0-approximated by a Legendrian isotopy with energy arbitrarily close to η/2. This in particular implies that the displacement energy of loose displaceable Legendrians is bounded by half the size of its smallest loose chart, which proves a conjecture of Dimitroglou Rizell and Sullivan. LÄS MER