Sökning: "Density estimation"

Visar resultat 1 - 5 av 194 avhandlingar innehållade orden Density estimation.

1. 1. EM Estimation in Phase Type Models

   Författare :Marita Olsson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
   Nyckelord :phase type distributions; coxian distribution; EM algorithm; I-divergence; density estimation; right censoring; interval censoring; standard error estimation; asymptotic theory; jackknife; relapse clinical trials; survival data; hidden Markov chain; I-divergence;

   Sammanfattning : This thesis consists of four articles whose theme in common is the class of phase type distributions. In the first article an EM algorithm is presented to estimate the parameters of a phase type distribution of fixed order. Also, it is shown that the algorithm can be used to approximate other continuous distributions by phase type distributions. LÄS MER

3. 2. Estimation of soil water retention for natural sediments from grain size distribution and bulk density

   Författare :Sven. A. Jonasson; Chalmers University of Technology; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; soil water characteristic curve; bulk density; Soil water retention curve; prediction; simple method; new method; Arya and Paris method; van Genuchten equation; grain size distribution; estimation; analytical equations;

   Sammanfattning : .... LÄS MER

4. 3. Maximum spacing methods and limit theorems for statistics based on spacings

   Författare :Magnus Ekström; Umeå universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Estimation; spacings; maximum spacing method; consistency; ^-divergence; goodness of fit; unimodal density; entropy estimation; uniform distribution;

   Sammanfattning : The maximum spacing (MSP) method, introduced by Cheng and Amin (1983) and independently by Ranneby (1984), is a general estimation method for continuous univariate distributions. The MSP method, which is closely related to the maximum likelihood (ML) method, can be derived from an approximation based on simple spacings of the Kullback-Leibler information. LÄS MER

5. 4. Model Reduction and Parameter Estimation for Diffusion Systems

   Författare :Bharath Bhikkaji; Torsten Söderström; Claes Breitholtz; Uppsala universitet; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diffusion system; Partial differential equations PDEs ; Model reduction; PDE solvers; Finite difference approximation; Chebyshev polynomials; System identification; Parameter estimation; Recursive estimation; Frequency domain estimation; Signal processing; Signalbehandling;

   Sammanfattning : Diffusion is a phenomenon in which particles move from regions of higher density to regions of lower density. Many physical systems, in fields as diverse as plant biology and finance, are known to involve diffusion phenomena. Typically, diffusion systems are modeled by partial differential equations (PDEs), which include certain parameters. LÄS MER

7. 5. Nonparametric Functional Estimation under Order Restrictions

   Författare :Dragi Anevski; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; monotonicity; convexity; deconvolution; kernel smoothing; NPMLE; long range dependence; greatest convex minorant; mixing; Density estimation; limit distribution.; regression; Mathematics; Matematik;

   Sammanfattning : This thesis consists of three papers (Papers A-C) on problems in nonparametric functional estimation, in particular density and regression function estimation and deconvolution, under order assumptions. Pointwise limit distribution results are stated for the obtained estimators, which include isotonic regression estimates, nonparametric maximum likelihood estimates of monotone densities, estimates of convex regression and density functions and deconvolution estimates. LÄS MER