Sökning: "Imputation"

Visar resultat 1 - 5 av 34 avhandlingar innehållade ordet Imputation.

1. 1. Multiple Kernel Imputation : A Locally Balanced Real Donor Method

   Författare :Nicklas Pettersson; Daniel Thorburn; Susanne Rässler; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bayesian Bootstrap; Boundary Effects; External Information; Kernel estimation features; Local Balancing; Pólya Sampling; statistik; Statistics;

   Sammanfattning : We present an algorithm for imputation of incomplete datasets based on Bayesian exchangeability through Pólya sampling. Each (donee) unit with a missing value is imputed multiple times by observed (real) values on units from a donor pool. The donor pools are constructed using auxiliary variables. LÄS MER

3. 2. Two Topics in Survey Methodology : Inference from Nonprobability Samples Using the Double Samples Setup

   Författare :Boris Lorenc; Daniel Thorburn; Lars Lyberg; Gösta Forsman; Stockholms universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; response process; establishment surveys; socially distributed cognition; response burden; measurement error; nonprobability samples; web surveys; double samples; propensity scores; model-based estimation; imputation; nonparametric imputation; weighting; Surveying; Lantmäteri;

   Sammanfattning : Modelling the response process in establishment surveys proceeded thus far by adding steps of operational character to the core cognitive steps of the individual cognitive model. Here (Paper 1) a larger unit of the cognitive analysis is posited: that part of the enterprise that is engaged in responding to a survey, consisting of one or more employees, the tools they use and the established practices of record keeping and survey responding. LÄS MER

4. 3. Statistical inference with deep latent variable models

   Författare :Najmeh Abiri; Beräkningsbiologi och biologisk fysik - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Deep Learning; Generative Models; Variational Inference; Missing data; Imputation; Fysicumarkivet A:2019:Abiri;

   Sammanfattning : Finding a suitable way to represent information in a dataset is one of the fundamental problems in Artificial Intelligence. With limited labeled information, unsupervised learning algorithms help to discover useful representations. LÄS MER

5. 4. Finding fitness : empirical and theoretical explorations of inferring fitness effects from population-level SNP data

   Författare :Bea Angelica Andersson; Xiao-Ru Wang; Åke Brännström; Tanja Slotte; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; distribution of fitness effects; site frequency spectra; missing data filtering; downsampling; imputation; sample size; population structure; inbreeding; selfing; homozygosity; Arabidopsis; Pinus; DFE-alpha; SLiM; population genomics; adaptation; biology; biologi; evolutionär genetik; evolutionary genetics; populationsbiologi; Population Biology; molekylärbiologi; Molecular Biology; Genetics; genetik;

   Sammanfattning : The distribution of fitness effects (DFE) describes the likelihood that a new mutation has a specific effect on the fitness of an individual in a given population. The shape of the DFE is a result of several factors such as population size, mating system and selective environment, and can in turn influence the evolutionary potential of a species. LÄS MER

7. 5. Attrition in Studies of Cognitive Aging

   Författare :Maria Josefsson; Xavier de Luna; Lars Nyberg; Anders Lundquist; Mattias Villani; Umeå universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Attrition; missing data; age-related cognitive change; non- ignorable dropout; monotone missing pattern; mixture models; pattern- mixture models; imputation; Statistics; statistik;

   Sammanfattning : Longitudinal studies of cognition are preferred to cross-sectional stud- ies, since they offer a direct assessment of age-related cognitive change (within-person change). Statistical methods for analyzing age-related change are widely available. LÄS MER