Sökning: "stationary"

Visar resultat 6 - 10 av 569 avhandlingar innehållade ordet stationary.

  1. 6. Multipole moments of axisymmetric spacetimes

    Detta är en avhandling från Matematiska institutionen

    Författare :Thomas Bäckdahl; Linköpings universitet.; Linköpings universitet.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multipole moments; axisymmetry; spacetimes; prescribed; solutions; static; stationary; Kerr; Weyl; Ernst; NATURAL SCIENCES Physics Other physics Theory of relativity; gravitation; NATURVETENSKAP Fysik Övrig fysik Relativitetsteori; gravitation;

    Sammanfattning : In this thesis we study multipole moments of axisymmetric spacetimes. Using the recursive definition of the multipole moments of Geroch and Hansen we develop a method for computing all multipole moments of a stationary axisymmetric spacetime without the use of a recursion. LÄS MER

  2. 7. Modelling and Inference using Locally Stationary Processes : Biomedical applications

    Detta är en avhandling från Lund University, Faculty of Science, Centre for Mathematical Sciences, Mathematical Statistics

    Författare :Rachele Anderson; Lunds universitet.; Lund University.; Lund University.; [2017-11]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Modelling of Time-Varying Signals; Locally Stationary Processes; Statistical Inference; Time-frequency Estimation; Regression; EEG Signals; HRV Signals;

    Sammanfattning : This thesis considers statistical methods for non-stationary signals, specifically stochastic modelling, inference on the model parameters and optimal spectral estimation. The models are based on Silverman’s definition of Locally Stationary Processes (LSPs). LÄS MER

  3. 8. Optical Design for Stationary Solar Concentrators

    Detta är en avhandling från Faculty of Engineering, LTH at Lund University

    Författare :Johan Nilsson; Lunds universitet.; Lund University.; [2007]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photovoltaic cells; parabolic reflectors; optical efficiency; Solar concentrators; photovoltaic-thermal systems; non-imaging optics; optical properties; building integrated photovoltaics; non uniform irradiance distribution; structured reflectors; solar cell modelling; ray tracing;

    Sammanfattning : Solar electricity is one of the most promising technologies for our future electricity supply. By using concentrators, it is possible to reduce the cost of generating photovoltaic electricity. This thesis discusses how to design stationary low concentrating systems for photovoltaic or PV/Thermal applications. LÄS MER

  4. 9. Estimation and Classification of Non-Stationary Processes : Applications in Time-Frequency Analysis

    Detta är en avhandling från Centre for Mathematical Sciences, Lund University

    Författare :Johan Brynolfsson; Lunds universitet.; Lund University.; Lund University.; Lunds universitet.; Lund University.; [2019-05-17]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time-Frequency Estimation; Parameter Estimation; Reassignment method; Non-Stationary Processes; Smooth spectral estimation; Neural Networks;

    Sammanfattning : This thesis deals with estimation and classification problems of non-stationary processes in a few special cases.In paper A and paper D we make strong assumptions about the observed signal, where a specific model is assumed and the parameters of the model are estimated. LÄS MER

  5. 10. Learning Stochastic Nonlinear Dynamical Systems Using Non-stationary Linear Predictors

    Detta är en avhandling från Stockholm, Sweden : KTH Royal Institute of Technology

    Författare :Mohamed Abdalmoaty; KTH.; [2017]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Stochastic Nonlinear Systems; Nonlinear System Identification; Learning Dynamical Models; Maximum Likelihood; Estimation; Process Disturbance; Prediction Error Method; Non-stationary Linear Predictors; Intractable Likelihood; Latent Variable Models; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The estimation problem of stochastic nonlinear parametric models is recognized to be very challenging due to the intractability of the likelihood function. Recently, several methods have been developed to approximate the maximum likelihood estimator and the optimal mean-square error predictor using Monte Carlo methods. LÄS MER