Sökning: "covariance function"

Visar resultat 16 - 20 av 76 avhandlingar innehållade orden covariance function.

  1. 16. Bayesian time series and panel models : unit roots, dynamics and random effects

    Författare :Mickael Salabasis; Handelshögskolan i Stockholm; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis consists of four papers and the main theme present is dependence, through time as in serial correlation, and across individuals, as in random effects. The individual papers may be grouped in many different ways. LÄS MER

  3. 17. On functions of a Wishart matrix and a normal vector with applications

    Författare :Edward Ngailo; Taras Bodnar; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical Statistics; matematisk statistik;

    Sammanfattning : This thesis consists of two papers which take a critical look on functions of an inverse Wishart matrix and a Gaussian vector. In the first paper, the product expression, of which the inverse of the pooled estimator of the covariance matrix is inverse Wishart distributed and the difference of sample means is multivariate normally distributed, is investigated by exploring the distributional properties via a stochastic representation for both the finite sample case and the infinite sample case under the large-dimensional asymptotic regime. LÄS MER

  4. 18. The Influence of APOE ε4 on the Hippocampus and Hippocampus-Dependent Memory

    Författare :Eva Stening; Hedvig Söderlund; Clare Mackay; Uppsala universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; APOE ε4; episodic memory; spatial memory; hippocampus;

    Sammanfattning : APOE ε4 is the major genetic risk factor for Alzheimer’s disease, a dementia characterized by memory impairment and hippocampal atrophy. While associated with episodic impairment and reduced hippocampal volume in healthy aging, APOE ε4 has been related to increased episodic memory performance in young adults. LÄS MER

  5. 19. Making Head or Tail of the Hippocampus : A Long-Axis Account of Episodic and Spatial Memory

    Författare :Jonas Persson; Hedvig Söderlund; Tomas Furmark; Asaf Gilboa; Uppsala universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; hippocampus; fMRI; episodic memory; spatial memory; gender differences; Psychology; Psykologi;

    Sammanfattning : While episodic and spatial memory both depend on the hippocampus, opposite gender differences in these functions suggest they are partly separate, with different neural underpinnings. The anterior and posterior hippocampus differ  in structure and whole-brain connectivity, and studies point to the posterior hippocampus being more involved in spatial memory while the anterior hippocampus’ role in episodic memory is less clear. LÄS MER

  7. 20. Coherent State Wave Functions on the Torus

    Författare :Mikael Fremling; Hans Hansson; Jon Magne Leinaas; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum Hall Effect; fysik; Physics;

    Sammanfattning : In the study of the quantum Hall effect there are still many unresolved problems. One of these is how to generate representative wave functions for ground states on other geometries than the planar and spherical. We study one such geometry, the toroidal one, where the periodic boundary conditions must be properly taken into account. LÄS MER