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Visar resultat 11 - 15 av 157 avhandlingar som matchar ovanstående sökkriterier.

  1. 11. Gibbs Measures and Phase Transitions in Potts and Beach Models

    Författare :Per Hallberg; KTH; []
    Nyckelord :Potts model; beach model; percolation; random-cluster model; Gibbs measure; coupling; Markov chains on infinite trees; critical exponent;

    Sammanfattning : The theory of Gibbs measures belongs to the borderlandbetween statistical mechanics and probability theory. In thiscontext, the physical phenomenon of phase transitioncorresponds to the mathematical concept of non-uniqueness for acertain type of probability measures.The most studied model in statistical mechanics is thecelebrated Ising model. LÄS MER

  3. 12. Roughening in dimer models : Random matrix statistics and surface fluctuations

    Författare :Scott Mason; Kurt Johansson; Alexey Bufetov; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Matematik; Mathematics;

    Sammanfattning : The field of mathematical statistical mechanics sits at the intersection of probability theory and mathematical physics. It consists of the rigorous analysis of models in statistical mechanics, such as dimer and lattice models - of which the Ising model is a classical example. LÄS MER

  4. 13. Characterization and Design Requirements for Antennas in the Near-field and the Random-LOS Propagation Environment

    Författare :Aidin Razavi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization-MIMO; Random-LOS; OTA; Antenna measurements; near-field antennas; antenna characterization; MIMO; near-field focusing;

    Sammanfattning : The choice of antenna for a particular application depends on the requirements imposed by that application. These can be, the application's field region (i.e., near-field or far-field), polarization, radiation pattern, radiation efficiency, system throughput, etc. LÄS MER

  5. 14. Characterization of Small Antennas & Wireless Devices for MIMO Systems in Rich Isotropic Multipath & Random Line-of-Sight

    Författare :Ahmed Hussain; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; Rayleigh; reverberation chamber; random LOS; RIMP; LTE; OTA;

    Sammanfattning : The current thesis is about over-the-air (OTA) performance characterization of wireless terminals in rich isotropic multipath (RIMP) environment as well as in pure line-of-sight (LOS) environment while not ignoring the random positions and orientations of the mobile terminals due to randomness of the user. The latest mobile wireless terminals such as iPhone and iPad can be used in any random position and orientation thereby making the received LOS-component toappear as a random voltage at the antenna ports. LÄS MER

  7. 15. Random walk boundaries: their entropies and connections with Hecke pairs

    Författare :Hanna Oppelmayer; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Poisson boundary; Hecke pairs; Non-singular dynamical systems; Schlichting completion; random walks on groups; non-monotone sequences of $ sigma$-algebras; Furstenberg entropy;

    Sammanfattning : We present three papers in non-singular dynamics concerning boundaries of random walks on locally compact, second countable groups. One common theme is entropy. Paper II and III are concerned with boundary entropy spectra, while Paper I studies topological properties of entropy. LÄS MER