Sökning: "Statistics"

Visar resultat 21 - 25 av 2183 avhandlingar innehållade ordet Statistics.

  1. 21. Sensitivity and Uncertainty Analysis Methods : with Applications to a Road Traffic Emission Model

    Författare :Olle Eriksson; Stig Danielsson; Rolf Sundberg; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Emission; Grid; Model; Pollutant; Response surface; Road traffic; Sensitivity analysis; Simulation; Uncertainty analysis; Avgaser; Vägtrafik; Miljöaspekter; Statistics; Statistik;

    Sammanfattning : There is always a need to study the properties of complex input–output systems, properties that may be very difficult to determine. Two such properties are the output’s sensitivity to changes in the inputs and the output’s uncertainty if the inputs are uncertain. LÄS MER

  3. 22. Monotonic and Semiparametric Regression for the Detection of Trends in Environmental Quality Data

    Författare :Mohamed Hussian; Anders Grimvall; Ali Hadi; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Normalisation; Monotonic; Semiparametric; Temporal trends; fluctuations; global; local; Matematisk statistik; Icke-parametriska metoder; Statistics; Statistik;

    Sammanfattning : Natural fluctuations in the state of the environment can long conceal or distort important trends in the human impact on our ecosystems. Accordingly, there is increasing interest in statistical normalisation techniques that can clarify the anthropogenic effects by removing meteorologically driven fluctuations and other natural variation in time series of environmental quality data. LÄS MER

  4. 23. Common features in vector nonlinear time series models

    Författare :Dao Li; Sune Karlsson; Kenneth Carling; Thomas Holgersson; Örebro universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nonliearity; time series; econometrics; smooth transition; common features; cointegration; forecasting; residual-based; ppp; Statistics; Statistik; Complex Systems – Microdata Analysis;

    Sammanfattning : This thesis consists of four manuscripts in the area of nonlinear time series econometrics on topics of testing, modeling and forecasting nonlinear common features. The aim of this thesis is to develop new econometric contributions for hypothesis testing and forecasting in thesearea.Both stationary and nonstationary time series are concerned. LÄS MER

  5. 24. Calibration Adjustment for Nonresponse in Sample Surveys

    Författare :Bernardo João Rota; Thomas Laitila; Sune Karlsson; Risto Lehtonen; Örebro universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Auxiliary variables; Calibration; Nonresponse; principal com-ponents; regression estimator; response probability; survey sampling; two-step estimator; variance estimator; weighting; Statistics; Statistik;

    Sammanfattning : In this thesis, we discuss calibration estimation in the presence of nonresponse with a focus on the linear calibration estimator and the propensity calibration estimator, along with the use of different levels of auxiliary information, that is, sample and population levels. This is a fourpapers- based thesis, two of which discuss estimation in two steps. LÄS MER

  7. 25. Scalable Bayesian spatial analysis with Gaussian Markov random fields

    Författare :Per Sidén; Mattias Villani; Anders Eklund; Håvard Rue; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spatial statistics; Bayesian statistics; Gaussian Markov random fields; fMRI; Machine learning; Spatial statistik; Bayesiansk statistik; Gaussiska Markov-fält; fMRI; Maskininlärning;

    Sammanfattning : Accurate statistical analysis of spatial data is important in many applications. Failing to properly account for spatial autocorrelation may often lead to false conclusions. LÄS MER