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

"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 2019 Pennsylvania State University

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 2019 Iowa State University

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 2019 Iowa State University

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 2019 Iowa State University

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 2019 Iowa State University

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 2019 Iowa State University

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 2019 University of Chicago

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 2019 Valparaiso University

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 2019 University of Nevada, Reno

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 2019 Augsburg University

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 2019 University of North Carolina at Asheville

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 2019 Valparaiso University

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 2019 Illinois State University

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 2019 Western Kentucky University

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 2019 University of Liverpool

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 2019 Iowa State University

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 2019 Iowa State University

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 2019 Iowa State University

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 2019 Missouri University of Science and Technology

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.


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