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Full-Text Articles in Statistics and Probability

"A Comparison Of Variable Selection Methods Using Bootstrap Samples From Environmental Metal Mixture Data", Paul-Yvann Djamen 4785403, Paul-Yvann Djamen Jul 2020

"A Comparison Of Variable Selection Methods Using Bootstrap Samples From Environmental Metal Mixture Data", Paul-Yvann Djamen 4785403, Paul-Yvann Djamen

Mathematics & Statistics ETDs

In this thesis, I studied a newly developed variable selection method SODA, and three customarily used variable selection methods: LASSO, Elastic net, and Random forest for environmental mixture data. The motivating datasets have neuro-developmental status as responses and metal measurements and demographic variables as covariates. The challenges for variable selections include (1) many measured metal concentrations are highly correlated, (2) there are many possible ways of modeling interactions among the metals, (3) the relationships between the outcomes and explanatory variables are possibly nonlinear, (4) the signal to noise ratio in the real data may be low. To compare these methods ...


What Have Long-Term Field Studies Taught Us About Population Dynamics?, Beth A. Reinke, David A. W. Miller, Fredric J. Janzen Nov 2019

What Have Long-Term Field Studies Taught Us About Population Dynamics?, Beth A. Reinke, David A. W. Miller, Fredric J. Janzen

Ecology, Evolution and Organismal Biology Publications

Long-term studies have been crucial to the advancement of population biology, especially our understanding of population dynamics. We argue that this progress arises from three key characteristics of long-term research. First, long-term data are necessary to observe the heterogeneity that drives most population processes. Second, long-term studies often inherently lead to novel insights. Finally, long-term field studies can serve as model systems for population biology, allowing for theory and methods to be tested under well-characterized conditions. We illustrate these ideas in three long-term field systems that have made outsized contributions to our understanding of population ecology, evolution, and conservation biology ...


Phylogenetic Comparative Methods And The Evolution Of Multivariate Phenotypes, Dean C. Adams, Michael L. Collyer Nov 2019

Phylogenetic Comparative Methods And The Evolution Of Multivariate Phenotypes, Dean C. Adams, Michael L. Collyer

Ecology, Evolution and Organismal Biology Publications

Evolutionary biology is multivariate, and advances in phylogenetic comparative methods for multivariate phenotypes have surged to accommodate this fact. Evolutionary trends in multivariate phenotypes are derived from distances and directions between species in a multivariate phenotype space. For these patterns to be interpretable, phenotypes should be characterized by traits in commensurate units and scale. Visualizing such trends, as is achieved with phylomorphospaces, should continue to play a prominent role in macroevolutionary analyses. Evaluating phylogenetic generalized least squares (PGLS) models (e.g., phylogenetic analysis of variance and regression) is valuable, but using parametric procedures is limited to only a few phenotypic ...


Application Of Models To Screwworm Eradication Programs, E. S. Krafsur Oct 2019

Application Of Models To Screwworm Eradication Programs, E. S. Krafsur

Elliot Krafsur

Screwworms (Cochliomyia hominivorax, Diptera: Calliphoridae) were eradicated from the United States with E.F. Knipling's 'demonstrative' model that related the relative mating proportions of wild and sterile insects to population fertility and predicted population trends in subsequent generations. Ad hoc correlations between treatments applied and experimental results obtained on Sanibel Island, Florida, in 1952-1953, Curacao, Netherlands East Indies in 1954, and the Florida mainland in 1957 provided a conceptual guide for the eradication campaigns from 1958 until 1967. Many mathematical models have since been proposed that relate pest insect population density at some future time to density, fertility, net ...


Climate Warming Trends In The U.S. Midwest Using Four Thermal Models, Lori J. Abendroth, Fernando E. Miguez, Michael J. Castellano, Jerry L. Hatfield Oct 2019

Climate Warming Trends In The U.S. Midwest Using Four Thermal Models, Lori J. Abendroth, Fernando E. Miguez, Michael J. Castellano, Jerry L. Hatfield

Michael Castellano

Thermal time (TT) is an agro-climate index widely established and used in predicting plant development based on temperature. This index is a powerful tool for measuring multi-faceted changes in temperature occurring from climate change. In the present study, TT was calculated for the entire frost-free period and individual spring, summer, and fall seasons using growing degree day (GDD), general thermal index (GTI), crop heat unit (CHU), and heat stress degree day (HSDD) models for 1054 counties across 12 Midwest states on a daily basis from 1950 to 2017. The temporal trend for each county was fit with a linear regression ...


Long-Run Impacts Of Trade Shocks And Export Competitiveness: Evidence From The U.S. Bse Event, Chen-Ti Chen, John M. Crespi, William Hahn, Lee L. Schulz, Fawzi Taha Oct 2019

Long-Run Impacts Of Trade Shocks And Export Competitiveness: Evidence From The U.S. Bse Event, Chen-Ti Chen, John M. Crespi, William Hahn, Lee L. Schulz, Fawzi Taha

John Crespi

This paper examines how comparative advantages of major beef exporters changed following the 2003 bovine spongiform encephalopathy outbreak (BSE), which significantly disrupted the U.S. beef trade until approximately April 2007. Using longitudinal data on beef export values and constructed revealed comparative advantage measures, we show that while some measure of the long-run impacts of BSE on U.S. beef export competitiveness have returned to pre-2003 levels, the U.S.’s comparative advantage has not. We also examine a hypothetical scenario of no BSE event in 2003 and predict what exporters’ competitiveness would have looked like. The authors discuss the ...


Long-Run Impacts Of Trade Shocks And Export Competitiveness: Evidence From The U.S. Bse Event, Chen-Ti Chen, John M. Crespi, William Hahn, Lee L. Schulz, Fawzi Taha Oct 2019

Long-Run Impacts Of Trade Shocks And Export Competitiveness: Evidence From The U.S. Bse Event, Chen-Ti Chen, John M. Crespi, William Hahn, Lee L. Schulz, Fawzi Taha

Lee Schulz

This paper examines how comparative advantages of major beef exporters changed following the 2003 bovine spongiform encephalopathy outbreak (BSE), which significantly disrupted the U.S. beef trade until approximately April 2007. Using longitudinal data on beef export values and constructed revealed comparative advantage measures, we show that while some measure of the long-run impacts of BSE on U.S. beef export competitiveness have returned to pre-2003 levels, the U.S.’s comparative advantage has not. We also examine a hypothetical scenario of no BSE event in 2003 and predict what exporters’ competitiveness would have looked like. The authors discuss the ...


Teaching Data Analysis Using Students' Own Data, Dmitry Kondrashov, Stefano Allesina Oct 2019

Teaching Data Analysis Using Students' Own Data, Dmitry Kondrashov, Stefano Allesina

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


An Agent-Based Modeling Approach For Predicting The Behavior Of Bighead Carp (Hypophthalmichthys Nobilis) Under The Influence Of Acoustic Deterrence, Joey Gaudy, Craig Garzella Oct 2019

An Agent-Based Modeling Approach For Predicting The Behavior Of Bighead Carp (Hypophthalmichthys Nobilis) Under The Influence Of Acoustic Deterrence, Joey Gaudy, Craig Garzella

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Network Structure And Dynamics Of Biological Systems, Deena R. Schmidt Oct 2019

Network Structure And Dynamics Of Biological Systems, Deena R. Schmidt

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Quantifying Distribution In Carbon Uptake Across A Global Measurement Network Of Terrestrial Ecosystems, John Zobitz, Madeline Oswood Oct 2019

Quantifying Distribution In Carbon Uptake Across A Global Measurement Network Of Terrestrial Ecosystems, John Zobitz, Madeline Oswood

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Integrating Mathematics And Biology In The Classroom: A Compendium Of Case Studies And Labs, Becky Sanft, Anne Walter Oct 2019

Integrating Mathematics And Biology In The Classroom: A Compendium Of Case Studies And Labs, Becky Sanft, Anne Walter

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Quantifying Pollen Traits To Build A Mathematical Model Of Pollen Competition - A Biologist's Perspective, Rob Swanson, Alex Capaldi Oct 2019

Quantifying Pollen Traits To Build A Mathematical Model Of Pollen Competition - A Biologist's Perspective, Rob Swanson, Alex Capaldi

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Classification Of Coronary Artery Disease In Non-Diabetic Patients Using Artificial Neural Networks, Demond Handley Oct 2019

Classification Of Coronary Artery Disease In Non-Diabetic Patients Using Artificial Neural Networks, Demond Handley

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


A Study On Discrete And Discrete Fractional Pharmacokinetics-Pharmacodynamics Models For Tumor Growth And Anti-Cancer Effects, Ferhan Atici, Ngoc Nguyen Oct 2019

A Study On Discrete And Discrete Fractional Pharmacokinetics-Pharmacodynamics Models For Tumor Growth And Anti-Cancer Effects, Ferhan Atici, Ngoc Nguyen

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Automated Monitoring Of Behaviour In Zebrafish After Invasive Procedures, Anthony G. Deakin, Jonathan Buckley, Hamzah S. Alzu'bi, Andrew R. Cossins, Joseph W. Spencer, Waleed Al'nuaimy, Iain S. Young, Jack S. Thomson, Lynne U. Sneddon Oct 2019

Automated Monitoring Of Behaviour In Zebrafish After Invasive Procedures, Anthony G. Deakin, Jonathan Buckley, Hamzah S. Alzu'bi, Andrew R. Cossins, Joseph W. Spencer, Waleed Al'nuaimy, Iain S. Young, Jack S. Thomson, Lynne U. Sneddon

Lynne Sneddon, PhD

Fish are used in a variety of experimental contexts often in high numbers. To maintain their welfare and ensure valid results during invasive procedures it is vital that we can detect subtle changes in behaviour that may allow us to intervene to provide pain-relief. Therefore, an automated method, the Fish Behaviour Index (FBI), was devised and used for testing the impact of laboratory procedures and efficacy of analgesic drugs in the model species, the zebrafish. Cameras with tracking software were used to visually track and quantify female zebrafish behaviour in real time after a number of laboratory procedures including fin ...


Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song Oct 2019

Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song

William Q Meeker

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination withmodel-assisted POD (MAPOD) methods. With the development of advanced physics-basedmethods, such as ultrasonic NDTtesting, the empirical information,needed for POD methods, can bereduced. However, performing accurate numerical simulationscan be prohibitivelytime-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the ...


Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song Oct 2019

Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song

Jiming Song

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination withmodel-assisted POD (MAPOD) methods. With the development of advanced physics-basedmethods, such as ultrasonic NDTtesting, the empirical information,needed for POD methods, can bereduced. However, performing accurate numerical simulationscan be prohibitivelytime-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the ...


Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song Oct 2019

Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song

Robert Grandin

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination withmodel-assisted POD (MAPOD) methods. With the development of advanced physics-basedmethods, such as ultrasonic NDTtesting, the empirical information,needed for POD methods, can bereduced. However, performing accurate numerical simulationscan be prohibitivelytime-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the ...


An Optimal Edg Method For Distributed Control Of Convection Diffusion Pdes, X. Zhang, Y. Zhang, John R. Singler Oct 2019

An Optimal Edg Method For Distributed Control Of Convection Diffusion Pdes, X. Zhang, Y. Zhang, John R. Singler

Mathematics and Statistics Faculty Research & Creative Works

We propose an embedded discontinuous Galerkin (EDG) method to approximate the solution of a distributed control problem governed by convection diffusion PDEs, and obtain optimal a priori error estimates for the state, dual state, their uxes, and the control. Moreover, we prove the optimize-then-discretize (OD) and discrtize-then-optimize (DO) approaches coincide. Numerical results confirm our theoretical results.


An Animal-Assisted Intervention Study In The Nursing Home: Lessons Learned, Lonneke G. J. A. Schuurmans, Inge Noback, Jos M. G. A. Schols, Marie-Jose Enders-Slegers Sep 2019

An Animal-Assisted Intervention Study In The Nursing Home: Lessons Learned, Lonneke G. J. A. Schuurmans, Inge Noback, Jos M. G. A. Schols, Marie-Jose Enders-Slegers

People and Animals: The International Journal of Research and Practice

AAI studies in the nursing home pose a specific set of challenges. In this article the practical and ethical issues encountered during a Dutch psychogeriatric nursing home AAI study are addressed with the aim of sharing our experiences for future researchers as well as AAI practitioners in general.

In our study we compared three groups of clients with dementia who participated in group sessions of either visiting dog teams, visiting FurReal Friend robot animals, or visiting students (control group) and monitored the effect on social interaction and neuropsychiatric symptoms through video analysis and questionnaires. We encountered the following four categories ...


North American Extreme Precipitation Events And Related Large-Scale Meteorological Patterns: A Review Of Statistical Methods, Dynamics, Modeling, And Trends, Mathew Barlow, William J. Gutowski Jr., John R. Gyakum, Richard W. Katz, Young‑Kwon Lim, Russ S. Schumacher, Michael F. Wehner, Laurie Agel, Michael Bosilovich, Allison Collow, Alexander Gershunov, Richard Grotjahn, Ruby Leung, Shawn Milrad, Seung‑Ki Min Sep 2019

North American Extreme Precipitation Events And Related Large-Scale Meteorological Patterns: A Review Of Statistical Methods, Dynamics, Modeling, And Trends, Mathew Barlow, William J. Gutowski Jr., John R. Gyakum, Richard W. Katz, Young‑Kwon Lim, Russ S. Schumacher, Michael F. Wehner, Laurie Agel, Michael Bosilovich, Allison Collow, Alexander Gershunov, Richard Grotjahn, Ruby Leung, Shawn Milrad, Seung‑Ki Min

William J. Gutowski, Jr.

This paper surveys the current state of knowledge regarding large-scale meteorological patterns (LSMPs) associated with short-duration (less than 1 week) extreme precipitation events over North America. In contrast to teleconnections, which are typically defined based on the characteristic spatial variations of a meteorological field or on the remote circulation response to a known forcing, LSMPs are defined relative to the occurrence of a specific phenomenon—here, extreme precipitation—and with an emphasis on the synoptic scales that have a primary influence in individual events, have medium-range weather predictability, and are well-resolved in both weather and climate models. For the LSMP ...


Fully Bayesian Analysis Of Allele-Specific Rna-Seq Data, Ignacio Alvarez-Castro, Jarad Niemi Sep 2019

Fully Bayesian Analysis Of Allele-Specific Rna-Seq Data, Ignacio Alvarez-Castro, Jarad Niemi

Jarad Niemi

Diploid organisms have two copies of each gene, called alleles, that can be separately transcribed. The RNA abundance associated to any particular allele is known as allele-specific expression (ASE). When two alleles have polymorphisms in transcribed regions, ASE can be studied using RNA-seq read count data. ASE has characteristics different from the regular RNA-seq expression: ASE cannot be assessed for every gene, measures of ASE can be biased towards one of the alleles (reference allele), and ASE provides two measures of expression for a single gene for each biological samples with leads to additional complications for single-gene models. We present ...


Closed-Form Probability Distribution Of Number Of Infections At A Given Time In A Stochastic Sis Epidemic Model.Pdf, Michael Otunuga Sep 2019

Closed-Form Probability Distribution Of Number Of Infections At A Given Time In A Stochastic Sis Epidemic Model.Pdf, Michael Otunuga

Olusegun Michael Otunuga

We study the effects of external fluctuations in the transmission rate of certain diseases and how these affect the distribution of the number of infected individuals over time. To do this, we introduce random noise in the transmission rate in a deterministic SIS model and study how the number of infections changes over time. The objective of this work is to derive and analyze the closed form probability distribution of the number of infections at a given time in the resulting stochastic SIS epidemic model. Using the Fokker-Planck equation, we reduce the differential equation governing the number of infections to ...


Animal Research, Accountability, Openness And Public Engagement: Report From An International Expert Forum, Elisabeth H. Ormandy, Daniel M. Weary, Katarina Cvek, Mark Fisher, Kathrin Herrmann, Pru Hobson-West, Michael Mcdonald, William Milsom, Margaret Rose, Andrew Rowan, Joanne Zurlo, Marina A.G. Von Keyserlingk Sep 2019

Animal Research, Accountability, Openness And Public Engagement: Report From An International Expert Forum, Elisabeth H. Ormandy, Daniel M. Weary, Katarina Cvek, Mark Fisher, Kathrin Herrmann, Pru Hobson-West, Michael Mcdonald, William Milsom, Margaret Rose, Andrew Rowan, Joanne Zurlo, Marina A.G. Von Keyserlingk

Andrew N. Rowan, DPhil

In November 2013, a group of international experts in animal research policy (n = 11) gathered in Vancouver, Canada, to discuss openness and accountability in animal research. The primary objective was to bring together participants from various jurisdictions (United States, Sweden, Australia, New Zealand, Germany, Canada and the United Kingdom) to share practices regarding the governance of animals used in research, testing and education, with emphasis on the governance process followed, the methods of community engagement, and the balance of openness versus confidentiality. During the forum, participants came to a broad consensus on the need for: (a) evidence-based metrics to allow ...


Measuring Circuit Splits: A Cautionary Note, Aaron-Andrew P. Bruhl Sep 2019

Measuring Circuit Splits: A Cautionary Note, Aaron-Andrew P. Bruhl

Aaron-Andrew P. Bruhl

A number of researchers have recently published new measures of the Supreme Court’s behavior in resolving conflicts in the lower courts. These new measures represent an improvement over prior, cruder approaches, but it turns out that measuring the Court’s resolutions of conflicts is surprisingly difficult. The aim of this methodological comment is to describe those difficulties and to establish several conclusions that follow from them. First, the new measures of the Court’s behavior are certainly imprecise and may reflect biased samples. Second, using the Supreme Court Database, which some studies rely on to assemble a dataset of ...


Identifying Marginal Treatment Effects In The Presence Of Sample Selection, Otávio Bartalotti, Desire Kedagni, Vitor Possebom Sep 2019

Identifying Marginal Treatment Effects In The Presence Of Sample Selection, Otávio Bartalotti, Desire Kedagni, Vitor Possebom

Otávio Bartalotti

This article presents identification results for the marginal treatment effect (MTE) when there is sample selection. We show that the MTE is partially identified for individuals who are always observed regardless of treatment, and we derive sharp bounds on this parameter under four sets of assumptions. The first identification result combines the standard MTE assumptions without any restrictions to the sample selection mechanism. The second result imposes monotonicity of the sample selection variable with respect to the treatment, considerably shrinking the identified set. Third, we incorporate a stochastic dominance assumption which tightens the lower bound for the MTE. Finally, we ...


Identifying Marginal Treatment Effects In The Presence Of Sample Selection, Otávio Bartalotti, Desire Kedagni, Vitor Possebom Sep 2019

Identifying Marginal Treatment Effects In The Presence Of Sample Selection, Otávio Bartalotti, Desire Kedagni, Vitor Possebom

Desire Kedagni

This article presents identification results for the marginal treatment effect (MTE) when there is sample selection. We show that the MTE is partially identified for individuals who are always observed regardless of treatment, and we derive sharp bounds on this parameter under four sets of assumptions. The first identification result combines the standard MTE assumptions without any restrictions to the sample selection mechanism. The second result imposes monotonicity of the sample selection variable with respect to the treatment, considerably shrinking the identified set. Third, we incorporate a stochastic dominance assumption which tightens the lower bound for the MTE. Finally, we ...


Utilization Of Statistics For Provision Of Business Information: Implementation Of Α-Sutte Indicator On Provision Of Stock Movement Prediction Information, Nuning Kurniasih, Ansari Saleh Ahmar, Nanik Kurniawati Sep 2019

Utilization Of Statistics For Provision Of Business Information: Implementation Of Α-Sutte Indicator On Provision Of Stock Movement Prediction Information, Nuning Kurniasih, Ansari Saleh Ahmar, Nanik Kurniawati

Library Philosophy and Practice (e-journal)

The Current information services are dealing with big data that is freely accessible. Companies providing information services and products need to develop creativity and innovation to maintain their existence. In this paper, we offer that information specialist can add value to information. The added value is given through an analysis of information that is relevant to user needs. The Research and Development Method can be used to develop a framework for service information products and services, and bridge the gap between the theories studied in higher education and the needs of the industry. α-Sutte Indicator can be used to predict ...


Student Insights Report, Fall 2019, The Center For Student Analytics Sep 2019

Student Insights Report, Fall 2019, The Center For Student Analytics

Publications

For the past three years, the staff of the Center for Student Analytics have worked to discover and expose meaningful, data-informed insights into what helps students succeed at Utah State University. The following pages highlight 20 of the most useful insights we found provided here in small sets that will be useful to students, faculty, staff, university leadership, parents, and even prospective students. As you explore this report, we encourage you to see the student data as a window into USU itself. While big data helps us understand how individual students are performing, it tells us a great deal more ...