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Filtering by: Creator Emerson, Sarah Remove constraint Creator: Emerson, Sarah Committee Member Wickham, Charlotte Remove constraint Committee Member: Wickham, Charlotte

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  • On the Use of Baseline Values in Randomized Clinical Trials

    Creator:
    Castillo Roldan, Alejandra M.
    Abstract:
    In many scientific settings, investigators are interested in the effect of a new treatment. To have a point of comparison data is collected from patients before treatment groups are assigned. When seeking to test the presence of a significant treatment effect it may be unclear how baseline measurements should be...
    Resource Type:
    Masters Thesis
    Full Text:
    Baseline Values in Randomized Clinical Trials Abstract approved: Sarah C. Emerson In many scientific

  • Localized Variable Selection with Random Forest

    Creator:
    Niyaghi, Faraz
    Abstract:
    Due to recent advances in computer technology, the cost of collecting and storing data has dropped drastically. This makes it feasible to collect large amounts of information for each data point. This increasing trend in feature dimensionality justifies the need for research on variable selection. Random forest (RF) has demonstrated...
    Resource Type:
    Dissertation
    Full Text:
    _________________________ Sarah C. Emerson Sharmodeep Bhattacharyya Due

  • Positive graphical lasso estimation of sparse inverse covariance matrices

    Creator:
    Logan, Paul
    Abstract:
    We explore the possibility of estimating sparse inverse covariance matrices when for scientific reasons the covariance matrix is restricted to be a non-negative matrix. The process mirrors the graphical lasso process developed by Friedman and others(2008) that did not have this additional constraint.Accordingly, the Lasso procedure is done through coordinate...
    Resource Type:
    Capstone Project

  • Information Criterion for Nonparametric Model-Assisted Survey Estimators

    Creator:
    James, Addison
    Abstract:
    Nonparametric model-assisted estimators have been proposed to improve estimates of finite population parameters. More efficient estimators are obtained when the parametric model is misspecified due to the flexibility of nonparametric models. In this dissertation, we derive information criteria to select appropriate auxiliary variables to use in an additive model-assisted method....
    Resource Type:
    Dissertation
    Full Text:
    University: Dr. Alix Gitelman, Dr. Sarah Emerson, Dr. Cliff Pereira, Dr. Yanming Di, Dr. Claudio Feuntes

  • A Linear Mixed Model Framework for Spatio-Temporal Random Processes using the Separable and Product-Sum Covariance Structures

    Creator:
    Dumelle, Michael J.
    Abstract:
    We describe spatio-temporal random processes using linear mixed models and discuss estimation, inference, and prediction under this formulation. We show how many commonly used covariances are special cases of this more general framework and pay special attention to the separable and product-sum covariances. The linear mixed model formulation facilitates straightforward...
    Resource Type:
    Dissertation
    Full Text:
    research. I want to thank my Statistics Department committee members (Masters and PhD), Sarah Emerson

  • Statistical methods for serially correlated zero-inflated proportions

    Creator:
    Sun, Luna
    Abstract:
    Proportion data falling in the continuum (0, 1) are very common in practice. It can also happen that an inflated number of zeros (or ones) occur with proportion data. There are extensive studies of zero-inflated data in the literature. Almost all of them, however, focus on zero-inflated count data. Furthermore,...
    Resource Type:
    Dissertation
    Full Text:
    iconic gentle smile on his face. I thank Dr. Sarah Emerson for having discussion with me about some