Multivariate Analysis Commons^™

Poverty And Disability: A Vicious Circle? Evidence From Afghanistan And Zambia, Jean-Francois Trani, Mitchell M. Loeb

Brown School Faculty Publications

Disability and poverty have a complex and interdependent relationship. It is commonly understood that persons with disabilities are more likely to be poor and that poverty may contribute to sustaining disability. This interdependency is revealed not only through an examination of poverty in terms of income but also on a broader scale through other poverty related dimensions. Just how robust is this link? This paper compares data collected from household surveys in Afghanistan and Zambia, and explores the potential link between multidimensional poverty and disability. We find evidence of lower access to health care, education and labour market for people …

A Comparative Analysis Of Decision Trees Vis-À-Vis Other Computational Data Mining Techniques In Automotive Insurance Fraud Detection, Adrian Gepp, Kuldeep Kumar, J Holton Wilson, Sukanto Bhattacharya

Adrian Gepp

No abstract provided.

Modeling Dependence Using Skew T Copulas: Bayesian Inference And Applications, Michael S. Smith, Quan Gan, Robert Kohn

Michael Stanley Smith

[THIS IS AN AUGUST 2010 REVISION THAT REPLACES ALL PREVIOUS VERSIONS.]

We construct a copula from the skew t distribution of Sahu, Dey & Branco (2003). This copula can capture asymmetric and extreme dependence between variables, and is one of the few copulas that can do so and still be used in high dimensions effectively. However, it is difficult to estimate the copula model by maximum likelihood when the multivariate dimension is high, or when some or all of the marginal distributions are discrete-valued, or when the parameters in the marginal distributions and copula are estimated jointly. We therefore propose …

Estimation Of Copula Models With Discrete Margins Via Bayesian Data Augmentation, Michael S. Smith, Mohamad A. Khaled

Michael Stanley Smith

Estimation of copula models with discrete margins is known to be difficult beyond the bivariate case. We show how this can be achieved by augmenting the likelihood with latent variables, and computing inference using the resulting augmented posterior. To evaluate this we propose two efficient Markov chain Monte Carlo sampling schemes. One generates the latent variables as a block using a Metropolis-Hasting step with a proposal that is close to its target distribution, the other generates them one at a time. Our method applies to all parametric copulas where the conditional copula functions can be evaluated, not just elliptical copulas …

Toxicity Profiling Of Engineered Nanomaterials Via Multivariate Dose Response Surface Modeling, Trina Patel, Donatello Telesca, Saji George, Andre Nel

COBRA Preprint Series

New generation in-vitro high throughput screening (HTS) assays for the assessment of engineered nanomaterials provide an opportunity to learn how these particles interact at the cellular level, particularly in relation to injury pathways. These types of assays are often characterized by small sample sizes, high measurement error and high dimensionality as multiple cytotoxicity outcomes are measured across an array of doses and durations of exposure. In this article we propose a probability model for toxicity profiling of engineered nanomaterials. A hierarchical framework is used to account for the multivariate nature of the data by modeling dependence between outcomes and thereby …

Geographic Disparities Associated With Stroke And Myocardial Infarction In East Tennessee, Ashley Pedigo Golden

Doctoral Dissertations

Stroke and myocardial infarction (MI) are serious conditions whose burdens vary by socio-demographic and geographic factors. Although several studies have investigated and identified disparities in burdens of these conditions at the county and state levels, little is known regarding their geographic epidemiology at the neighborhood level. Both conditions require emergency treatments and therefore timely geographic accessibility to appropriate care is critical. Investigation of disparities in geographic accessibility to stroke and MI care and the role of Emergency Medical Services (EMS) in reducing treatment delays are vital in improving health outcomes. Therefore, the objectives of this work were to: (i) classify …

Energy Functional For Nuclear Masses, Michael Giovanni Bertolli

Doctoral Dissertations

An energy functional is formulated for mass calculations of nuclei across the nuclear chart with major-shell occupations as the relevant degrees of freedom. The functional is based on Hohenberg-Kohn theory. Motivation for its form comes from both phenomenology and relevant microscopic systems, such as the three-level Lipkin Model. A global fit of the 17-parameter functional to nuclear masses yields a root- mean-square deviation of χ[chi] = 1.31 MeV, on the order of other mass models. The construction of the energy functional includes the development of a systematic method for selecting and testing possible functional terms. Nuclear radii are computed within …

Water Quality Models For Stormwater Runoff In Two Lincoln, Nebraska Urban Watersheds, Jake Fisher

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Water quality monitoring was conducted in two urban watersheds (Colonial Hills and Taylor Park) located in southeast Lincoln, NE over a three year period spanning from October 2008 through September 2011. In-line probes continuously measured for turbidity, conductivity, dissolved oxygen, and water temperature while other water quality constituents were analyzed for discrete water samples collected using grab and automatic sampling techniques. The water quality data was used to calculate event mean concentrations (EMCs) for sixteen storm events sampled over the duration of the project period. Three types of stormwater quality multiple linear regression models were developed for the estimation of …

Likelihood Based Population Independent Component Analysis, Ani Eloyan, Ciprian M. Crainiceanu, Brian S. Caffo

Johns Hopkins University, Dept. of Biostatistics Working Papers

Independent component analysis (ICA) is a widely used technique for blind source separation, used heavily in several scientific research areas including acoustics, electrophysiology and functional neuroimaging. We propose a scalable two-stage iterative true group ICA methodology for analyzing population level fMRI data where the number of subjects is very large. The method is based on likelihood estimators of the underlying source densities and the mixing matrix. As opposed to many commonly used group ICA algorithms the proposed method does not require significant data reduction by a twofold singular value decomposition. In addition, the method can be applied to a large …

Depicting Estimates Using The Intercept In Meta-Regression Models: The Moving Constant Technique, Blair T. Johnson Dr., Tania B. Huedo-Medina Dr.

CHIP Documents

In any scientific discipline, the ability to portray research patterns graphically often aids greatly in interpreting a phenomenon. In part to depict phenomena, the statistics and capabilities of meta-analytic models have grown increasingly sophisticated. Accordingly, this article details how to move the constant in weighted meta-analysis regression models (viz. “meta-regression”) to illuminate the patterns in such models across a range of complexities. Although it is commonly ignored in practice, the constant (or intercept) in such models can be indispensible when it is not relegated to its usual static role. The moving constant technique makes possible estimates and confidence intervals at …

An Occupational-Based Experimental Study Of Collective Vs. Personal Efficacy To Encourage Sun Protective Behaviors In Head Start Preschool Teachers, Elizabeth A. Holzhauser

Loma Linda University Electronic Theses, Dissertations & Projects

Background. Skin cancer is one of the most common types of cancers in the United States. An analysis of literature shows that skin cancer can be partially mitigated through personal behavior changes (Glanz, Buller, & Saraiya; 2007, Canadian Centre of Occupational Health and Safety [CCOHS], 2010). Currently national sun-safety educational campaigns promote sun-protective behaviors to individuals who receive exposure due to their work environment (Task Force on Community Preventive Services, 2004). Preschool teachers employed with San Bernardino County Head Start are inadvertently exposed to sunlight during mandatory recess periods posing risks to their health.

Purpose. This study evaluated two instructional …

Multiple Testing Of Local Maxima For Detection Of Peaks In Chip-Seq Data, Armin Schwartzman, Andrew Jaffe, Yulia Gavrilov, Clifford A. Meyer

Harvard University Biostatistics Working Paper Series

No abstract provided.

Manova: Type I Error Rate Analysis, Christopher Dau Wei Ling

Statistics

No abstract provided.

Perceived Parent-Child Relationship And High-Risk Behaviors Among Christian College Students, Karla G. Lavin Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Background. Adolescents and young adults today are participating in high-risk behaviors such as dangerous sexual behaviors and drug and alcohol abuse at high rates. An increased incidence of negative effects associated with the aforementioned behaviors has led researchers to examine factors that influence and protect adolescents from certain devastating effects (Davis, Hendershot, George, Norris, & Heiman, 2007; Goldstein, Bamett, Pedlow, & Murphy, 2007; Hamilton, et al., 2007; Hingson, Heeren, & Winter, 2006; Hingson, Heeren, Winter, & Wechsler, 2003; Hingson, Heeren, Zakocs, Winter, & Wechsler, 2003; McCarty, et al., 2004; Mokdad, Marks, Stroup, & Gerberding, 2004; Mosher, Chandra, & Jones, 2005; …

Mixture Model Cluster Analysis Under Different Covariance Structures Using Information Complexity, Bahar Erar

Masters Theses

In this thesis, a mixture-model cluster analysis technique under different covariance structures of the component densities is developed and presented, to capture the compactness, orientation, shape, and the volume of component clusters in one expert system to handle Gaussian high dimensional heterogeneous data sets to achieve flexibility in currently practiced cluster analysis techniques. Two approaches to parameter estimation are considered and compared; one using the Expectation-Maximization (EM) algorithm and another following a Bayesian framework using the Gibbs sampler. We develop and score several forms of the ICOMP criterion of Bozdogan (1994, 2004) as our fitness function; to choose the number …

Statistical Analysis Of Fatalities Due To Vehicle Accidents In Las Vegas, Nv, Annabelle Marie Mathis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this thesis is to investigate factors that affect the odds of having a fatality in a vehicle collision. We will be looking at characteristics of the driver that caused the accident (age, gender, behavior, actions, influences, and seat belt worn), the characteristics of the vehicle the driver drove (type of vehicle, and air bag deployment), the characteristics of the environment in which the accident occurred (weather, road condition, lighting, time of day, the day of the week, and month of the year), the characteristics of the crash (direction of accident and how many vehicles were involved), and …

Impact Of An Online Support System On Health Related Quality Of Life Among Men Diagnosed With Prostate Cancer, Daniel K. Osei

Loma Linda University Electronic Theses, Dissertations & Projects

Prostate cancer is a major public health issue worldwide and a significant cause of male cancer death in the USA. Though early screening and treatment has greatly enhanced the outcome, men diagnosed with prostate cancer face problems that compromise quality of life after treatment. Online support for prostate cancer clients is a convenient way to help because it is anonymous, inexpensive, and can be used at clients’ convenience. Yet few studies have explored how these supports impact these clients. This study used a longitudinal randomized experimental design to examine the impact of online services on quality of life of prostate …

Identifying Unique Neighborhood Characteristics To Guide Health Planning For Stroke And Heart Attack: Fuzzy Cluster And Discriminant Analyses Approaches, Ashley Pedigo, William Seaver, Agricola Odoi

Agricola Odoi

Background: Socioeconomic, demographic, and geographic factors are known determinants of stroke and myocardial infarction (MI) risk. Clustering of these factors in neighborhoods needs to be taken into consideration during planning, prioritization and implementation of health programs intended to reduce disparities. Given the complex and multidimensional nature of these factors, multivariate methods are needed to identify neighborhood clusters of these determinants so as to better understand the unique neighborhood profiles. This information is critical for evidence-based health planning and service provision. Therefore, this study used a robust multivariate approach to classify neighborhoods and identify their socio-demographic characteristics so as to provide …

Diagnostic Checking, Time Series And Regression, Esam Mahdi

Electronic Thesis and Dissertation Repository

In this thesis, a new univariate-multivariate portmanteau test is derived. The proposed test statistic can be used for diagnostic checking ARMA, VAR, FGN, GARCH, and TAR time series models as well as for checking randomness of series and goodness-of- fit VAR models with stable Paretian errors. The asymptotic distribution of the test statistic is derived as well as a chi-square approximation. However, the Monte-Carlo test is recommended unless the series is very long. Extensive simulation experiments demonstrate the usefulness of this test and its improved power performance compared to widely used previous multivariate portmanteau diagnostic check. The contributed R package …

On The Covariate-Adjusted Estimation For An Overall Treatment Difference With Data From A Randomized Comparative Clinical Trial, Lu Tian, Tianxi Cai, Lihui Zhao, L. J. Wei

Harvard University Biostatistics Working Paper Series

No abstract provided.