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Full-Text Articles in Physical Sciences and Mathematics

A Machine Learning Approach For Predicting Clinical Trial Patient Enrollment In Drug Development Portfolio Demand Planning, Ahmed Shoieb May 2023

A Machine Learning Approach For Predicting Clinical Trial Patient Enrollment In Drug Development Portfolio Demand Planning, Ahmed Shoieb

Masters Theses

One of the biggest challenges the clinical research industry currently faces is the accurate forecasting of patient enrollment (namely if and when a clinical trial will achieve full enrollment), as the stochastic behavior of enrollment can significantly contribute to delays in the development of new drugs, increases in duration and costs of clinical trials, and the over- or under- estimation of clinical supply. This study proposes a Machine Learning model using a Fully Convolutional Network (FCN) that is trained on a dataset of 100,000 patient enrollment data points including patient age, patient gender, patient disease, investigational product, study phase, blinded …


Random Search Plus: A More Effective Random Search For Machine Learning Hyperparameters Optimization, Bohan Li Dec 2020

Random Search Plus: A More Effective Random Search For Machine Learning Hyperparameters Optimization, Bohan Li

Masters Theses

Machine learning hyperparameter optimization has always been the key to improve model performance. There are many methods of hyperparameter optimization. The popular methods include grid search, random search, manual search, Bayesian optimization, population-based optimization, etc. Random search occupies less computations than the grid search, but at the same time there is a penalty for accuracy. However, this paper proposes a more effective random search method based on the traditional random search and hyperparameter space separation. This method is named random search plus. This thesis empirically proves that random search plus is more effective than random search. There are some case …


Empirical Modeling Of Used Nuclear Fuel Radiation Emissions For Safeguards Purposes, Amanda M. Bachmann Aug 2020

Empirical Modeling Of Used Nuclear Fuel Radiation Emissions For Safeguards Purposes, Amanda M. Bachmann

Masters Theses

For nuclear nonproliferation safeguards, the ability to characterize used nuclear fuel (UNF) is a vital process. Fuel characterization allows for independent verification by inspectors of operator declarations of the special nuclear material flow and nuclear related activities within a facility, and an estimation of fissile material remaining in a fuel assembly. Current methods to verify this information rely heavily on non-destructive assay techniques, such as gamma spectroscopy and neutron detection measurements. While these measurements are effective tools for estimating a specific characteristic of the fuel, such as burnup or cooling time, they often require an accurate estimation of a select …


Developing Leading And Lagging Indicators To Enhance Equipment Reliability In A Lean System, Dhanush Agara Mallesh Dec 2017

Developing Leading And Lagging Indicators To Enhance Equipment Reliability In A Lean System, Dhanush Agara Mallesh

Masters Theses

With increasing complexity in equipment, the failure rates are becoming a critical metric due to the unplanned maintenance in a production environment. Unplanned maintenance in manufacturing process is created issues with downtimes and decreasing the reliability of equipment. Failures in equipment have resulted in the loss of revenue to organizations encouraging maintenance practitioners to analyze ways to change unplanned to planned maintenance. Efficient failure prediction models are being developed to learn about the failures in advance. With this information, failures predicted can reduce the downtimes in the system and improve the throughput.

The goal of this thesis is to predict …


Spatially Explicit Population Estimates Of The Florida Black Bear, Jacob Michael Humm May 2017

Spatially Explicit Population Estimates Of The Florida Black Bear, Jacob Michael Humm

Masters Theses

The Florida black bear (Ursus americanus floridanus) is currently comprised of 7 isolated subpopulations: Apalachicola, Eglin, Osceola, Ocala/St. Johns, Chassahowitzka, Highlands/Glades, and Big Cypress. The last statewide assessment of Florida black bear population dynamics was conducted by Simek et al. (2005) using traditional capture-markrecapture methods. The subspecies was removed from Florida’s List of State Threatened Species in 2012 contingent upon the formulation of a management plan that would maintain viable subpopulations of black bears in suitable habitat. Accurate population estimates for each of the remaining black bear subpopulations in Florida were needed to achieve the management goals of …


Regional Dynamic Price Relationships Of Distillers Dried Grains In U.S. Feed Markets, Matthew Fulton Johnson Aug 2016

Regional Dynamic Price Relationships Of Distillers Dried Grains In U.S. Feed Markets, Matthew Fulton Johnson

Masters Theses

Distillers dried grains with solubles (DDGS) is now a mainstream substitute in U.S. animal feed rations. DDGS is rich in fat and protein content and serves as a competitive feed source in livestock markets. The objective of this study is to identify dynamic price relationships among DDGS, corn, soybean meal, and livestock outputs in context of specific livestock sectors and their geographic location. Four locations associated with a predominant livestock sector are selected for analysis by measuring density and relative proportion of a livestock sector’s grain consumption at the county level. A vector error correction model is applied to post-mandate …


Effects Of Bullying And Victimization On Friendship Selection, Reciprocation, And Maintenance In Elementary School Children, Marisa Lynn Whitley May 2016

Effects Of Bullying And Victimization On Friendship Selection, Reciprocation, And Maintenance In Elementary School Children, Marisa Lynn Whitley

Masters Theses

This study examined the effects of elementary school children’s bullying and victimization experiences on their friendships over time. The majority of children experience acts of aggression or bullying before the end of elementary school, and bullying and peer victimization is associated with academic, social, behavioral, and psychological difficulties. This study used social networks analysis (R SIENA 4.0) to examine whether peer reports of forms of bullying and victimization (i.e., overt and relational) affect the likelihood of friendship selection, reciprocation, and maintenance in 2nd-4th grade children. Children (N = 143) from the Midwestern region of the United …


Modelling Supercomputer Maintenance Interrupts: Maintenance Policy Recommendations, Jagadish Cherukuri Aug 2015

Modelling Supercomputer Maintenance Interrupts: Maintenance Policy Recommendations, Jagadish Cherukuri

Masters Theses

A supercomputer is a repairable system with large number of compute nodes interconnected to work in harmony to achieve superior computational performance. Reliability of such a complex system depends on an effective maintenance strategy that involves both emergency and preventive maintenance. This thesis analyzes the maintenance records of four supercomputers operational at The National Institute of Computational Science located at Oak Ridge National Laboratory. We propose to use the generalized proportional intensities model (GPIM) to model the maintenance interrupts as it can capture both the reliability parameters and maintenance parameters and allows the inclusion of both emergency and preventive maintenance. …


Statistical Mechanics And Schramm-Loewner Evolution With Applications To Crack Propagation Processes, Christopher Borut Mesic Aug 2014

Statistical Mechanics And Schramm-Loewner Evolution With Applications To Crack Propagation Processes, Christopher Borut Mesic

Masters Theses

Schramm-Loewner Evolution (SLE) has both mathematical and physical roots that extend as far back as the early 20th century. We present the progression of these humble roots from the Ideal Gas Law, all the way to the renormalization group and conformal field theory, to better understand the impact SLE has had on modern statistical mechanics. We then explore the potential application of the percolation exploration process to crack propagation processes, illustrating the interplay between mathematics and physics.


Comparison Of Triangle And Tetrad Discrimination Methodology In Applied, Industrial Manner, Sara Lyn Carlisle Aug 2014

Comparison Of Triangle And Tetrad Discrimination Methodology In Applied, Industrial Manner, Sara Lyn Carlisle

Masters Theses

The triangle method has been widely used in the food industry for many years when conducting sensory discrimination testing. Recently, however, another discrimination testing method, the tetrad, has begun to gain popularity. Based on currently published research, the tetrad method possesses statistical advantages over the triangle and would require fewer panelists, reduce testing time, and use less sample material. More testing is needed to confirm these advantages in an applied, industrial approach on a wider range of products. Over thirty triangles and thirty tetrads with untrained panelists have been completed in order to compare the two methods. Products tested ranged …


Mapping Spatial Thematic Accuracy Using Indicator Kriging, Maria I. Martinez Dec 2013

Mapping Spatial Thematic Accuracy Using Indicator Kriging, Maria I. Martinez

Masters Theses

Thematic maps derived from remote sensing imagery is increasingly being used in environmental and ecological modeling. Spatial information in these maps however is not free of error. Different methodologies such as error matrices are used to assess the accuracy of the spatial information. However, most of the methods commonly used for describing the accuracy assessment of thematic data fail to describe spatial differences of the accuracy across an area of interest. This thesis describes the use of indicator kriging as a geostatistical method for mapping the spatial accuracy of thematic maps. The method is illustrated by constructing accuracy maps for …


Mussel Survivorship, Growth Rate And Shell Decay Rate In The New River Basin Of Tennessee: An Experimental Approach Using Corbicula Fluminea, Grant Andrew Mincy Aug 2012

Mussel Survivorship, Growth Rate And Shell Decay Rate In The New River Basin Of Tennessee: An Experimental Approach Using Corbicula Fluminea, Grant Andrew Mincy

Masters Theses

The New River Basin (NRB) of Tennessee is home to a number of rare endemic aquatic communities. One such community of particular importance to the area, experiencing a precipitous population decline due to the fouling and pollution of their freshwater systems, is that of freshwater mussels (Bogan 2006). This study in the NRB involves measuring the mortality rates of live Asian clams (Corbicula fluminea) assemblages and the shell decay rates of their death assemblages. This study also examines the decay rates of the native Villosa iris to gather information on molluscan health and the ability of their shells …


Identifying The Spatial Distribution Of Three Plethodontid Salamanders In Great Smoky Mountains National Park Using Two Habitat Modeling Methods, Matthew Stephen Kookogey May 2012

Identifying The Spatial Distribution Of Three Plethodontid Salamanders In Great Smoky Mountains National Park Using Two Habitat Modeling Methods, Matthew Stephen Kookogey

Masters Theses

The main objective was to create habitat models of three plethodontid salamander species (Desmognathus conanti, D. ocoee, and Plethodon jordani) in GSMNP. To investigate the relationships between salamanders and their habitats, I used three models—logistic regression with use-availability sampling, logistic regression with case-control sampling, and Mahalanobis distance (D2)—for each species to gain a robust view of the relationships. The secondary objective was to compare the different modeling methods within and across the three species. Elevation was the dominant variable for all three species.

D2 for D. conanti predicted low elevations, close proximity …


Examining Impacts On Water Demand Resulting From Population And Employment Growth Using A Regional Adjustment Model, Steven Blake Thomas May 2012

Examining Impacts On Water Demand Resulting From Population And Employment Growth Using A Regional Adjustment Model, Steven Blake Thomas

Masters Theses

This thesis examines the currently available water use data and its limitation for use in scientific research. The first chapter offers a description of the current nationwide water data including descriptions of collection methods and trends found within the data. The varying collection methods used result in inconsistencies within the datasets and between the years. These inconsistencies have resulted in the data being used more as a point of reference than in nationwide empirical analysis of water use. There has been a calling for systematic improvements to the data, which could contribute to greater empirical analysis taking place at the …


Mixture Model Cluster Analysis Under Different Covariance Structures Using Information Complexity, Bahar Erar Aug 2011

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 …


A Study Of Missing Data Imputation And Predictive Modeling Of Strength Properties Of Wood Composites, Yan Zeng Aug 2011

A Study Of Missing Data Imputation And Predictive Modeling Of Strength Properties Of Wood Composites, Yan Zeng

Masters Theses

Problem: Real-time process and destructive test data were collected from a wood composite manufacturer in the U.S. to develop real-time predictive models of two key strength properties (Modulus of Rupture (MOR) and Internal Bound (IB)) of a wood composite manufacturing process. Sensor malfunction and data “send/retrieval” problems lead to null fields in the company’s data warehouse which resulted in information loss. Many manufacturers attempt to build accurate predictive models excluding entire records with null fields or using summary statistics such as mean or median in place of the null field. However, predictive model errors in validation may be higher …


An Analysis Of Boosted Regression Trees To Predict The Strength Properties Of Wood Composites, Dillon Matthew Carty Aug 2011

An Analysis Of Boosted Regression Trees To Predict The Strength Properties Of Wood Composites, Dillon Matthew Carty

Masters Theses

The forest products industry is a significant contributor to the U.S. economy contributing six percent of the total U.S. manufacturing gross domestic product (GDP), placing it on par with the U.S. automotive and plastics industries. Sustaining business competitiveness by reducing costs and maintaining product quality will be essential in the long term for this industry. Improved production efficiency and business competitiveness is the primary rationale for this work. A challenge facing this industry is to develop better knowledge of the complex nature of process variables and their relationship with final product quality attributes. Quantifying better the relationships between process variables …


Exploring The Effectiveness Of Environmentally Sustainable Practices In Municipal Government: A Case Study Of The City Of Knoxville’S Department Of Parks And Recreation, Anthony Michael Brown Aug 2011

Exploring The Effectiveness Of Environmentally Sustainable Practices In Municipal Government: A Case Study Of The City Of Knoxville’S Department Of Parks And Recreation, Anthony Michael Brown

Masters Theses

Sustainability practices produce programs and services that meet current needs while preserving the environment and natural resources for the future. City parks and recreation departments are facing budget shortfalls and increasing expectations from customers. Governments are now embracing sustainability practices to create financial savings while also fostering relations with customers.

The purpose of this single case study was twofold: (1) to examine the effectiveness of one city department’s strategies in outsourcing its environmental sustainability program through a performance contract with Ameresco; and (2) to examine the perceptions of key department employees about the effectiveness of the sustainability initiative. A …


Bayesian Logistic Regression Model For Siting Biomass-Using Facilities, Xia Huang Dec 2010

Bayesian Logistic Regression Model For Siting Biomass-Using Facilities, Xia Huang

Masters Theses

Key sources of oil for western markets are located in complex geopolitical environments that increase economic and social risk. The amalgamation of economic, environmental, social and national security concerns for petroleum-based economies have created a renewed emphasis on alternative sources of energy which include biomass. The stability of sustainable biomass markets hinges on improved methods to predict and visualize business risk and cost to the supply chain.

This thesis develops Bayesian logistic regression models, with comparisons of classical maximum likelihood models, to quantify significant factors that influence the siting of biomass-using facilities and predict potential locations in the 13-state Southeastern …


A Statistical Analysis Of Key Factors Influencing The Location Of Biomass-Using Facilities, Xu Liu Dec 2009

A Statistical Analysis Of Key Factors Influencing The Location Of Biomass-Using Facilities, Xu Liu

Masters Theses

Bioenergy and biofuels are emerging industries in the U.S. economy that will require statistical and economical analyses of woody biomass resources, supply chains, and other key factors that influence the siting of industrial facilities. This thesis develops models using logistic regression to improve the understanding of the key factors that influence the locations of existing wood-using bioenergy and biofuels plants, and other wood-using plants. The scope of the study is 13 Southeastern states.1 Logistic regression models are developed at the state and regional levels. The resolution of the study is the ZIP Code tabulation area (ZCTA). There are 9,416 …


Analyzing The Effects Of Coupons And Promotion In The Grocery Retail Sector, Milena Hanna Chotard Aug 2008

Analyzing The Effects Of Coupons And Promotion In The Grocery Retail Sector, Milena Hanna Chotard

Masters Theses

Modern scanner technology is pervasive throughout the retailing sector of the economy and is almost universal in the food retail industry. Along with loyalty programs, it has led to the development of massive databases which accurately and proficiently track the purchasing habits of customers. Making use of this information is one of the most important efforts in the management of this sector to further increase profitability.

This thesis explores the application of several statistical techniques to extract specific information from two large databases of customer purchasing behavior at a major US grocery chain. In particular, we first focus on the …


Reliability Analysis Of Oriented Strand Board’S Strength With A Simulation Study Of The Median Censored Method For Estimating Of Lower Percentile Strength, Yang Wang Aug 2007

Reliability Analysis Of Oriented Strand Board’S Strength With A Simulation Study Of The Median Censored Method For Estimating Of Lower Percentile Strength, Yang Wang

Masters Theses

Oriented Strand Board (OSB), an engineered wood product, has gained increased market acceptance as a construction material. Because of its growing market, the product’s manufacturing and performance have become the focus of much research. Internal Bond (IB) and Parallel and Perpendicular Elasticity Indices (EI), are important strength metrics of OSB and are analyzed in this thesis using statistical reliability methods. The data for this thesis consists of 529 destructive tests of OSB panels. They were tested from July 2005 to January 2006. These OSB panels came from a modern OSB manufacture in the Southeastern United States with the wood furnish …


An Applied Statistical Reliability Analysis Of The Modulus Of Elasticity And The Modulus Of Rupture For Wood-Plastic Composites, Diane Goodman Perhac Aug 2007

An Applied Statistical Reliability Analysis Of The Modulus Of Elasticity And The Modulus Of Rupture For Wood-Plastic Composites, Diane Goodman Perhac

Masters Theses

Wood-plastic composites (WPC) are materials comprised of wood fiber within a thermoplastic matrix and are a growing and important source of alternative wood products in the forest products industry. WPC is gaining market share in the building industry because of durability/maintenance advantages of WPC over traditional wood products and because of the removal of chromated copper arsenate (CCA) pressuretreated wood from the market. The reliability methods outlined in this thesis can be used to improve the quality of WPC and lower manufacturing costs by reducing raw material inputs and minimizing WPC waste. Statistical methods are described for analyzing both tensile …


Examining Regression Analysis Beyond The Mean Of The Distribution Using Quantile Regression: A Case Study Of Modeling The Internal Bond Of Medium Density Fiberboard Using Multiple Linear Regression And Quantile Regression With An Example Of Reliability Methods Using R Software, Leslie Brooke Shaffer Aug 2007

Examining Regression Analysis Beyond The Mean Of The Distribution Using Quantile Regression: A Case Study Of Modeling The Internal Bond Of Medium Density Fiberboard Using Multiple Linear Regression And Quantile Regression With An Example Of Reliability Methods Using R Software, Leslie Brooke Shaffer

Masters Theses

The thesis examines the causality of the central tendency of the Internal Bond (IB) of Medium Density Fiberboard (MDF) with predictor variables from the MDF manufacturing process. Multiple linear regression (MLR) models are developed using a best model criterion for all possible subsets of IB for four MDF thickness products reported in inches, e.g., 0.750”, 0.625”, 0.6875”, and 0.500”. Quantile Regression (QR) models of the median IB are also developed.

The adjusted coefficient of determination (R2 a) of the MLR models range from 72% with 53 degrees of freedom to 81% with 42 degrees of freedom, respectively. The …


Advantages Of “Function Domain Sets” Confidence Intervals Over Hypotheses Comparison Tests Of One Mean Residual Life (Mrl) Function Dominating An Improved Baseline And Of Two Mrl Functions Comparisons With Applications In Modern Engineered Composite Wood Products: One Sample And Two Sample Cases. Also Exploring General Theory, Insights, And Applications Of Mrl Functions, Jonathan Cody Steele Aug 2006

Advantages Of “Function Domain Sets” Confidence Intervals Over Hypotheses Comparison Tests Of One Mean Residual Life (Mrl) Function Dominating An Improved Baseline And Of Two Mrl Functions Comparisons With Applications In Modern Engineered Composite Wood Products: One Sample And Two Sample Cases. Also Exploring General Theory, Insights, And Applications Of Mrl Functions, Jonathan Cody Steele

Masters Theses

In this thesis, we analyze mean residual life (MRL) functions and unique “function domain sets” confidence intervals to identify important opportunities for improving quality of medium density fiberboard (MDF). We stress these tools have tremendous potential for many other forest products (e.g., various composites, natural woods), not just MDF.

These “function domain sets” confidence intervals can assess variation in quality where one MRL function dominates an industrial baseline. Assessments of the internal bond of MDF illuminate opportunities for helpful improvements, plus perform valid statistical comparisons of different types of MDF. For example, these MRL methods detect a new, higher-valued MDF …


A Reliability Case Study On Estimating Extremely Small Percentiles Of Strength Data For The Continuous Improvement Of Medium Density Fiberboard Product Quality, Weiwei Chen Dec 2005

A Reliability Case Study On Estimating Extremely Small Percentiles Of Strength Data For The Continuous Improvement Of Medium Density Fiberboard Product Quality, Weiwei Chen

Masters Theses

The objective of this thesis is to better estimate extremely small percentiles of strength distributions for measuring failure process in continuous improvement initiatives. These percentiles are of great interest for companies, oversight organizations, and consumers concerned with product safety and reliability. The thesis investigates the lower percentiles for the quality of medium density fiberboard (MDF). The international industrial standard for measuring quality for MDF is internal bond (IB, a tensile strength test). The results of the thesis indicated that the smaller percentiles are crucial, especially the first percentile and lower ones.

The thesis starts by introducing the background, study objectives, …


Novel Algorithms And Datamining For Clustering Massive Datasets, Aruna K. Buddana May 2005

Novel Algorithms And Datamining For Clustering Massive Datasets, Aruna K. Buddana

Masters Theses

Clustering proteomics data is a challenging problem for any traditional clustering algorithm. Usually, the number of samples is much smaller than the number of protein peaks. The use of a clustering algorithm which does not take into consideration the number of feature of variables (here the number of peaks) is needed. An innovative hierarchical clustering algorithm may be a good approach. This work proposes a new dissimilarity measure for the hierarchical clustering combined with a functional data analysis. This work presents a specific application of functional data analysis (FDA) to a highthrouput proteomics study. The high performance of the proposed …


An Applied Statistical Reliability Analysis Of The Internal Bond Of Medium Density Fiberboard, David Joseph Edwards May 2004

An Applied Statistical Reliability Analysis Of The Internal Bond Of Medium Density Fiberboard, David Joseph Edwards

Masters Theses

The forest products industry has seen tremendous growth in recent years and has a huge impact on the economies of many countries. For example, in the state of Maine in 1997, the forest products industry accounted for 9 billion U.S. dollars for that year. In the state of Tennessee, for example in 2000, this figure was 22 billion U.S. dollars for that year. It has, therefore, become more important in this industry to focus on production higher quality products. Statistical reliability methods, among other techniques, have been employed to help monitor and improve the quality of forest products. With such …


Statistical Analysis And Forecast Of The University Of Tennessee Enrollment, Edward J. Boling Aug 1950

Statistical Analysis And Forecast Of The University Of Tennessee Enrollment, Edward J. Boling

Masters Theses

Statement of the Problem: It is the problem of this investigation to analyze by use of statistical methods the number of students enrolled at The University of Tennessee from 1899 to 1950, and with the aid of such analysis to forecast possible future enrollments.

The data used in this investigation will be limited in that only the resident students of that portion of The University of Tennessee which is located at Knoxville, Tennessee, will be used. Thus, the Colleges, Schools and Experiment Stations located in Memphis, Martin, Jackson, Columbia, Greeneville, Nashville, Crossville and Springfield, and the University extension work carried …


A Study Of The Retail And Wholesale Distribution Of Frozen Foods In Tennessee, John F. Boyd Iii Mar 1950

A Study Of The Retail And Wholesale Distribution Of Frozen Foods In Tennessee, John F. Boyd Iii

Masters Theses

[From the Introduction]

One of the most amazing stories to come from the foods business during the past decade is the growth of the frozen foods industry. Its rapid development, after having partially solved many perplexing problems of production and distribution, was somewhat accelerated by higher consumer incomes and wartime scarcities. Equally important is the fact that housewives have been relatively quick to adopt frozen foods. Therefore, today frozen foods are occupying an increasingly important position and the industry no longer considers itself as being in the "infant" stage of development.