Sökning: "stationary"

Visar resultat 6 - 10 av 564 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. 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

  5. 10. Predator responses to non-stationary rodent cycles

    Detta är en avhandling från Stockholm : Department of Zoology, Stockholm University

    Författare :Peter Hellström; Stockholms universitet.; [2014]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Buteo lagopus; Vulpes lagopus; Lemmus; Myodes; population cycles; predation; numerical response; functional response; arctic; lemmings; voles; fox; monitoring; raptors; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Regular fluctuations in population size, cycles, are common in small mammals and have important effects on predator populations and life histories. In this thesis, I identify long-term patterns and processes in two specialist predators, the arctic fox Vulpes lagopus and the rough-legged buzzard Buteo lagopus, in relation to their prey (lemmings and voles) and in the case of the arctic fox also to a dominant competitor, the red fox Vulpes vulpes. LÄS MER