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  • Statistics in Education: Contributions to Teaching and Data Analysis

    Creator:
    Totty, Njesa
    Abstract:
    In this dissertation we present a compilation of the research conducted during the author’s doctoral program. In the first part, we discuss a case study regarding the impact of scholar-ships on student success at Oregon State University (OSU). Specifically, we look at the grad-uation and retention rates and aim to...
    Resource Type:
    Dissertation
    Full Text:
    program and for that I thank them. I would like to thank Charlotte Wickham and Katie McLaughlin for

  • 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

  • Responses of juvenile coho salmon and larval lamprey to instream habitat restoration in a Pacific Northwest stream

    Creator:
    Gonzalez, Rosalinda
    Abstract:
    Large wood has been utilized in many restoration projects to improve in-stream habitat in the Pacific Northwest for salmon. However, the benefits of this practice remain the subject of ongoing debate and evaluation of these projects has scarcely been done for non-salmonid species such as lamprey. In this study we...
    Resource Type:
    Masters Thesis
    Full Text:
    like to thank my other committee members: Guillermo Giannico and Charlotte Wickham for their guidance

  • On Simpson’s Paradox for Discrete Lifetime Distributions

    Creator:
    Lebowitz, Daniel
    Abstract:
    In probability and statistics, Simpson’s paradox is an apparent paradox in which a trend is present in different groups, but is reversed when the groups are combined. Joel Cohen (1986) has shown that continuously distributed lifetimes can never have a Simpson’s paradox. We investigate the same question for discrete random...
    Resource Type:
    Capstone Project

  • Novel Extensions and New Applications for Nonparametric Self-Exciting Point Processes

    Creator:
    Boyd, Peter C.
    Abstract:
    In this dissertation I will demonstrate a novel application of self-exciting point process models to mass shooting data. I will also introduce two adaptations to the traditional nonparametric Hawkes process modeling framework. One such modification allows for the estimation of the additional productivity introduced by an event that is not...
    Resource Type:
    Dissertation
    Full Text:
    committee: Lisa Madsen, Lisa Ganio, Charlotte Wickham, and Jeff Bethel. Thank you all for being a part of

  • On Some Methods for Smoothing Distribution Functions

    Creator:
    Asante, Emmanuel
    Abstract:
    Methods that are applied to smooth distribution functions are useful in many applications. Areas of application include economics, financial markets and survival analysis. The empirical cumulative distribution function (ecdf) is unbiased and its asymptotic distribution is normal. However, the jump discontinuities of $\frac{1}{n}$ are undesirable in estimation because it makes...
    Resource Type:
    Masters Thesis

  • 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

  • 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:
    , Dr. Charlotte Wickham, Dr. Katherine Mclaughlin, and Dr. Bogdan Strimbu. My special acknowledgment

  • Estimating Forest Inventory Attributes Using Airborne LiDAR in Southwestern Oregon

    Creator:
    Shin, Joonghoon
    Abstract:
    This thesis mainly consists of two parts: (1) comparing statistical modeling methods based on the area-based approach (ABA) for predicting forest inventory attributes using airborne light detection and ranging (LiDAR) data (Chapter 2), and (2) suggesting a new methodology fusing the individual tree detection (ITD) approach and the ABA for...
    Resource Type:
    Masters Thesis

  • 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:
    committee members, Dr. Charlotte Wick- ham and Dr. Yuan Jiang for their insightful questions, encouragement