Sökning: "Group symmetry"

Visar resultat 1 - 5 av 91 avhandlingar innehållade orden Group symmetry.

  1. 1. Algorithmic Methods in Combinatorial Algebra

    Författare :Anna Torstensson; Algebra; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; algebraic geometry; field theory; Number Theory; maximal symmetry group; resultant; SAGBI basis; Orthogonal decomposition; algebra; group theory; Talteori; fältteori; algebraisk geometri; gruppteori;

    Sammanfattning : This thesis consists of a collection of articles all using and/or developing algorithmic methods for the investigation of different algebraic structures. Part A concerns orthogonal decompositions of simple Lie algebras. The main result of this part is that the symplectic Lie algebra C3 has no orthogonal decomposition of so called monomial type. LÄS MER

  3. 2. Circle maps with symmetry-breaking perturbations

    Författare :Anders B. Eriksson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; circle map; subharmonic perturbation; chaos transitions; renormalization group theory; quasiperiodicity;

    Sammanfattning : .... LÄS MER

  4. 3. Group-Theoretical Structure in Multispectral Color and Image Databases

    Författare :Thanh Hai Bui; Reiner Lenz; Björn Kruse; Jinhui Chao; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; group theory; PCA Principal Component Analysis ; CBIR; Content-based Image Retrieval ; filter; color; image; multispectral; database; Signal processing; Signalbehandling;

    Sammanfattning : Many applications lead to signals with nonnegative function values. Understanding the structure of the spaces of nonnegative signals is therefore of interest in many different areas. Hence, constructing effective representation spaces with suitable metrics and natural transformations is an important research topic. LÄS MER

  5. 4. Flexibility – a tool for chirality control in asymmetric catalysis

    Författare :Raivis Zalubovskis; Christina Moberg; Alexandre Alexakis; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; flexibility; symmetry; dissymmetry; asymmetric catalysis; chiral ligands; pseudo-C2; pseudo-CS; conformational study; rotation barrier; pyrrolidines; phospholanes; azepines; phosphepines; supramolecular; hydrogenation; allylic alkylation; silaboration; palladium; rhodium; nickel; platinum; iridium.; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis deals with the design and synthesis of ligands for asymmetric catalysis: palladium catalyzed allylic alkylations, and rho-dium and iridium catalyzed hydrogenations of olefins. Chirally flexible phosphepine ligands based on biphenyl were synthesized and their properties were studied. LÄS MER

  7. 5. On Symmetries and Metrics in Geometric Inference

    Författare :Giovanni Luca Marchetti; Danica Kragic; Anastasiia Varava; Emanuele Rodolà; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Machine Learning; Computational Geometry; Voronoi; Delaunay; Symmetry; Equivariance; Datalogi; Computer Science;

    Sammanfattning : Spaces of data naturally carry intrinsic geometry. Statistics and machine learning can leverage on this rich structure in order to achieve efficiency and semantic generalization. Extracting geometry from data is therefore a fundamental challenge which by itself defines a statistical, computational and unsupervised learning problem. LÄS MER