Sökning: "symmetric functions"

Visar resultat 1 - 5 av 62 avhandlingar innehållade orden symmetric functions.

  1. 1. On Boolean Functions in Symmetric-Key Ciphers

    Författare :Enes Pasalic; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; autocorrelation properties; correlation attacks; nonlinearity; resiliency; Boolean function; Stream ciphers; block ciphers; Informatics; systems theory; Informatik; systemteori;

    Sammanfattning : This thesis discusses new results on the design and the existence of cryptographically strong Boolean functions used in the design of stream and block ciphers. By interlinking theoretical results and computer search some open problems have been solved, that is, we have shown the existence of previously unknown classes of functions. LÄS MER

  3. 2. Skew-symmetric matrix pencils : stratification theory and tools

    Författare :Andrii Dmytryshyn; Bo Kågström; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Investigating the properties, explaining, and predicting the behaviour of a physical system described by a system (matrix) pencil often require the understanding of how canonical structure information of the system pencil may change, e.g., how eigenvalues coalesce or split apart, due to perturbations in the matrix pencil elements. LÄS MER

  4. 3. Quantum many-body systems exactly solved by special functions

    Författare :Martin Hallnäs; Edwin Langmann; Pavel Winternitz; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum many-body systems; integrable systems; special functions; Mathematical physics; Matematisk fysik;

    Sammanfattning : This thesis concerns two types of quantum many-body systems in one dimension exactly solved by special functions: firstly, systems with interactions localised at points and solved by the (coordinate) Bethe ansatz; secondly, systems of Calogero-Sutherland type, as well as certain recently introduced deformations thereof, with eigenfunctions given by natural many-variable generalisations of classical (orthogonal) polynomials. The thesis is divided into two parts. LÄS MER

  5. 4. Functions of Generalized Bounded Variation

    Författare :Martin Lind; Viktor Kolyada; Peter Oswald; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bounded p-variation; generalized bounded variation; modulus of continuity; function spaces; embeddings; Matematik; Mathematics;

    Sammanfattning : This thesis is devoted to the study of different generalizations of the classical conception of a function of bounded variation.First, we study the functions of bounded p-variation introduced by Wiener in 1924. We obtain estimates of the total p-variation (1.. LÄS MER

  7. 5. Finite Element Modelling of Fluid-Structure Interaction

    Författare :Göran Sandberg; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite Element Method; Coupled problem; fluid-structure interaction; Transient; Acoustics; Caviation; Time Stepping; Symmetric; Nonlinear acoustics; Submerged structures; finite element method; Coupled problem; Fluid-structure interaction; Transient; Acoustics; Cavitation; Time Stepping; Symmetric; Nonlinear acoustics; Submerged structures;

    Sammanfattning : The dynamic interaction between non-viscid, compressible fluid and an elastic structure is studied. Finte element formulations, using the weighted residual method, are derived. Different primary variables in the fluid domain are used and different source functions are considered. LÄS MER