Sökning: "simple rings"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden simple rings.

  1. 1. Ideals and Maximal Commutative Subrings of Graded Rings

    Författare :Johan Öinert; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ideals; simple rings; maximal commutativity; Crossed products; graded rings;

    Sammanfattning : This thesis is mainly concerned with the intersection between ideals and (maximal commutative) subrings of graded rings. The motivation for this investigation originates in the theory of C*-crossed product algebras associated to topological dynamical systems, where connections between intersection properties of ideals and maximal commutativity of certain subalgebras are well-known. LÄS MER

  3. 2. Wear of piston rings in hydrostatic transmissions

    Författare :Ulf Skytte af Sätra; Sören Andersson; Kenneth Holmberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; piston ring; surface roughness; texture; coating; wear; hydraulic motor; Construction engineering; Konstruktionsteknik; Mechanical engineering; Maskinteknik;

    Sammanfattning : This study focuses on the wear of piston rings in a hydraulic radial piston motor. The piston ring has to satisfy increasing demands for reliability and longer service life. It has two contacting surfaces, the face and the flank, and operates under a boundary lubrication state. LÄS MER

  4. 3. Optical properties of nanometer disks, holes and rings prepared by colloidal lithography

    Författare :Per Hanarp; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; colloidal lithography; nanoparticles; nanorings; localized surface plasmon resonance; electrostatic self-assembly; nanofabrication; sub-wavelength holes;

    Sammanfattning : The optical properties of nanostructures prepared by colloidal lithography are studied. Colloidal lithography is a fabrication approach based on a self-assembling pattern definition. An electrostatically self-assembled array of nanoparticles is used as a mask and combined with etching or deposition processes. LÄS MER

  5. 4. Formalizing Refinements and Constructive Algebra in Type Theory

    Författare :Anders Mörtberg; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Formalization of mathematics; refinements; constructive algebra; type theory; Coq; SSReflect;

    Sammanfattning : The extensive use of computers in mathematics and engineering has led to an increased demand for reliability in the implementation of algorithms in computer algebra systems. One way to increase the reliability is to formally verify that the implementations satisfy the mathematical theorems stating their specification. LÄS MER

  7. 5. Clutters and atomistic lattices

    Författare :Paul Vaderlind; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : {1,…,m}, (aπ(1) ˅...˅aπ(1)) ˄aπ(i+1) =0 for i=1 ,…,m-1. LÄS MER