Search for dissertations about: "the matrix"

Showing result 1 - 5 of 2779 swedish dissertations containing the words the matrix.

2. 1. Software tools for matrix canonical computations and web-based software library environments

   Author : Pedher Johansson; Bo Kågström; Erik. Elmroth; Alan Edelman; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Canonical structure; Jordan canonical form; controllability; StratiGraph; Matlab toolbox; Kronecker canonical form; matrix; matrix pencil; perturbation theory; closure hirerarchy; matrix stratification; control system; observability; Numerical analysis; Numerisk analys;

   Abstract : This dissertation addresses the development and use of novel software tools and environments for the computation and visualization of canonical information as well as stratification hierarchies for matrices and matrix pencils. The simplest standard shape to which a matrix pencil with a given set of eigenvalues can be reduced is called the Kronecker canonical form (KCF). READ MORE

4. 2. On the Ising problem and some matrix operations

   Author : Daniel Andrén; Roland Häggkvist; Henrik Eriksson; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ising problem; phase tansition; matrix multiplicatoin; matrix inversion; Discrete mathematics; Diskret matematik;

   Abstract : The first part of the dissertation concerns the Ising problem proposed to Ernst Ising by his supervisor Wilhelm Lenz in the early 20s. The Ising model, or perhaps more correctly the Lenz-Ising model, tries to capture the behaviour of phase transitions, i.e. how local rules of engagement can produce large scale behaviour. READ MORE

5. 3. Twisting it up the Quantum Way : On Matrix Models, q-deformations and Supersymmetric Gauge Theories

   Author : Rebecca Lodin; Maxim Zabzine; Taro Kimura; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Matrix models; Virasoro constraints; Virasoro algebra; W algebra; q-deformations; Supersymmetric gauge theories; Theoretical Physics; Teoretisk fysik;

   Abstract : The mathematical framework which quantum field theory constitutes has been very successful in describing nature. As an extension of such a framework, the idea of supersymmetry was introduced. This greatly simplified the mathematical description of the theories, making them more tractable. READ MORE

6. 4. The Origin-Destination Matrix Estimation Problem : Analysis and Computations

   Author : Anders Peterson; Jan Lundgren; Torbjörn Larsson; Lars-Göran Mattsson; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Traffic modelling; Travel demand; Origin--Destination matrix; Traffic flow observation; Detector allocation; Estimation.; OD-matris; Trafikflödesobservation; Detektorallokering; Skattning; Trafikmodellering; Reseefterfrågan; Optimization; systems theory; Optimeringslära; systemteori;

   Abstract : For most kind of analyses in the field of traffic planning, there is a need for origin--destination (OD) matrices, which specify the travel demands between the origin and destination nodes in the network. This thesis concerns the OD-matrix estimation problem, that is, the calculation of OD-matrices using observed link flows. READ MORE

7. 5. Modeling the covariance matrix of financial asset returns

   Author : Gustav Alfelt; Joanna Tyrcha; Taras Bodnar; Vasyl Golosnoy; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Realized covariance; Autoregressive time-series; Goodness-of-fit test; Matrix singularity; Portfolio theory; Wishart distribution; Matrix-variate gamma distribution; Parameter estimation; High-dimensional data; Moore-Penrose inverse; matematisk statistik; Mathematical Statistics;

   Abstract : The covariance matrix of asset returns, which describes the fluctuation of asset prices, plays a crucial role in understanding and predicting financial markets and economic systems. In recent years, the concept of realized covariance measures has become a popular way to accurately estimate return covariance matrices using high-frequency data. READ MORE