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Full-Text Articles in Physical Sciences and Mathematics

Applications Of Operations Research In Domestic Electric Utilities, Jametta Myers Dec 2008

Applications Of Operations Research In Domestic Electric Utilities, Jametta Myers

Theses and Dissertations

Since its inception in the 1950s, operations research has been used in a number of industries, including the energy industry. Documentation of its use in exploration, production, gasoline blending, oil spill management, coal mining, coal handling, and coal mixing is extensive. However, considerably less documented research exists for one significant customer of many of these products: the electric utility. This work reviews refereed literature from United States operations research journals that document the use of operations research in United States electric utility operations. Applications that centered specifically on the areas of thermal energy generation, transmission, distribution, capacity planning, electric power …


Energy Efficient Embedded System Design For Medical Care System Using Wireless Sensor Network, Qi Li Dec 2008

Energy Efficient Embedded System Design For Medical Care System Using Wireless Sensor Network, Qi Li

Theses and Dissertations

Recent surveys on medical service systems show that the cost of patient monitoring has grown significantly. The widespread use of portable digital medical device makes it possible to provide a more comprehensive tracking of patient conditions. However, the development of a full scale, distributed health monitoring system is much delayed due to the lack of efficient wireless communication in a large distributed network. This becomes a challenging research topic which is to find a way to provide accurate and real time patient information to medical experts in a fast, efficient and cost effective fashion. This paper proposes a novel solution …


Wireless Intelligent Structural Health Monitoring System, Belle Ashwin Dec 2008

Wireless Intelligent Structural Health Monitoring System, Belle Ashwin

Theses and Dissertations

Metal structures are susceptible to various types of damages, including corrosion, stress damage, pillowing deformation, cracks etc. These kinds of damages in the metal structures occur mainly due to operational conditions and exposure to the environment. Our research involves a portable integrated wireless sensor system with video camera and ultrasound capabilities which is being developed to investigate corrosion damage on real structures in real time. This system uses images of the metal surfaces, which are captured from an integrated wireless sensor and then quantified and analyzed using computational intelligence. The quantification of the obtained images is done with specialized component …


Performance Analysis Of A Light Weight Packet Scanner, Paras Gandhi Dec 2008

Performance Analysis Of A Light Weight Packet Scanner, Paras Gandhi

Theses and Dissertations

The growth of networks around the world has also given rise to threats like viruses and Trojans. This rise in threats has resulted in counter measures for these threats. These counter measures are in the form of applications called firewalls or IDS. The incorporation of these applications in the network results in some delay in communications. The aim of the experiment in this thesis is to measure the delay introduced by such a firewall in the best case and compare it with the communication done on a network without such an application. These experiments are done using a special miniature …


Tolerance Intervals In Random-Effects Models, Kakotan Sanogo Dec 2008

Tolerance Intervals In Random-Effects Models, Kakotan Sanogo

Theses and Dissertations

In the pharmaceutical setting, it is often necessary to establish the shelf life of a drug product and sometimes suitable to assess the risk of product failure at the desired expiry period. The current statistical methodology use confidence intervals for the predicted mean to establish the expiry period and prediction intervals for a predicted new assay value or a tolerance interval for a proportion of the population for use in a risk assessment. A major concern is that most methodology treat a homogeneous subpopulation, say batch, either as a fixed effect and therefore uses a fixed-effects regression model (Graybill, 1976) …


Computer-Aided Trauma Decision Making Using Machine Learning And Signal Processing, Soo-Yeon Ji Nov 2008

Computer-Aided Trauma Decision Making Using Machine Learning And Signal Processing, Soo-Yeon Ji

Theses and Dissertations

Over the last 20 years, much work has focused on computer-aided clinical decision support systems due to a rapid increase in the need for management and processing of medical knowledge. Among all fields of medicine, trauma care has the highest need for proper information management due to the high prevalence of complex, life-threatening injuries. In particular, hemorrhage, which is encountered in most traumatic injuries, is a dominant factor in determining survival in both civilian and military settings. This complication can be better managed using a more in-depth analysis of patient information. Trauma physicians must make precise and rapid decisions, while …


Applications Of The Bivariate Gamma Distribution In Nutritional Epidemiology And Medical Physics, Jolene Barker Sep 2008

Applications Of The Bivariate Gamma Distribution In Nutritional Epidemiology And Medical Physics, Jolene Barker

Theses and Dissertations

In this thesis the utility of a bivariate gamma distribution is explored. In the field of nutritional epidemiology a nutrition density transformation is used to reduce collinearity. This phenomenon will be shown to result due to the independent variables following a bivariate gamma model. In the field of radiation oncology paired comparison of variances is often performed. The bivariate gamma model is also appropriate for fitting correlated variances. A method for simulating bivariate gamma random variables is presented. This method is used to generate data from several bivariate gamma models and the asymptotic properties of a test statistic, suggested for …


Variable Selection In Competing Risks Using The L1-Penalized Cox Model, Xiangrong Kong Sep 2008

Variable Selection In Competing Risks Using The L1-Penalized Cox Model, Xiangrong Kong

Theses and Dissertations

One situation in survival analysis is that the failure of an individual can happen because of one of multiple distinct causes. Survival data generated in this scenario are commonly referred to as competing risks data. One of the major tasks, when examining survival data, is to assess the dependence of survival time on explanatory variables. In competing risks, as with ordinary univariate survival data, there may be explanatory variables associated with the risks raised from the different causes being studied. The same variable might have different degrees of influence on the risks due to different causes. Given a set of …


Using Simulation Optimization To Construct Efficient Screening Strategies For Cervical Cancer, Christodoulos Foufoulides Aug 2008

Using Simulation Optimization To Construct Efficient Screening Strategies For Cervical Cancer, Christodoulos Foufoulides

Theses and Dissertations

Cervical cancer is the second most common type of cancer in women worldwide. Because cervical cancer is usually asymptomatic until the disease is in its advanced stages, cervical screening is of central importance towards combating cervical cancer. Alternative screening strategies are evaluated from an economic point of view through cost-effectiveness analysis. In the literature however, studies perform cost-effectiveness analysis on a limited number of de facto or predetermined screening policies. At present, no attempt has been made to construct efficient screening strategies through optimization, before cost-effectiveness analysis is applied. In this study simulation optimization is used to construct efficient screening …


Generalized Second Price Auctions With Hierarchical Bidding, Kevin Bryan Jun 2008

Generalized Second Price Auctions With Hierarchical Bidding, Kevin Bryan

Theses and Dissertations

The sale of text advertisements on search engines using an auction format called Generalized Second Price (GSP) has become increasingly common. GSP is unique in that it allows bidders to revise their bid if they are unhappy with the result of the auction, and because the auction sells multiple units of a related good simultaneously. We model this sale as a hierarchical game with complete information, allowing one potential bidder to bid in each stage. The hierarchical game has an entirely different set of equilibria from the simultaneous bid game studied in earlier research on this auction. Under hierarchical bidding, …


Mechanistic Studies On The Electrochemistry Of Glutathione And Homocysteine, Olufemi Oyesanya Apr 2008

Mechanistic Studies On The Electrochemistry Of Glutathione And Homocysteine, Olufemi Oyesanya

Theses and Dissertations

This research work has investigated the electrochemistry of glutathione (GSH)and homocysteine (HCSH) in order to develop sensors for these biological thiols.Ru(bpy)33+ and IrCl62− have been used as mediators for the electrooxidation of GSH andHCSH because direct oxidation of these thiols is slow at most conventional electrodes.The electrochemical detection of GSH and HCSH has been pursued because of their biological roles.

Concerted proton electron transfer (CPET) and stepwise proton electron transfer(PT/ET) pathways have been observed in the electrooxidation of GSH and HCSH.Oxidation of GSH by Ru(bpy)33+ carried out in deuterated and undeuterated buffered (pH= pD …


An Scir Model Of Meningococcal Meningitis, Kalimah Vereen Jan 2008

An Scir Model Of Meningococcal Meningitis, Kalimah Vereen

Theses and Dissertations

A model for meningitis is developed by adding a class of carriers to the basic SIR model. This model is used to analyze the impact a vaccination program can have on the health of the population of epidemic prone countries. Analysis of the model shows the local stability of the disease free equilibrium, the existence of an endemic equilibrium and computation of the reproduction number, ℜ0 . Using a MATLAB program we simulate a time course of the model using parameters gathered from the World Health Organization. The numerical solution demonstrates that our reproduction number was correct. We thenconcluded that …


An Agent-Based Model To Study The Spread And Control Of Epidemics, Ashley Dawn Fuller Jan 2008

An Agent-Based Model To Study The Spread And Control Of Epidemics, Ashley Dawn Fuller

Theses and Dissertations

The world continues to face outbreaks of disease due to natural causes as well as the threat of biological warfare. Mathematical modeling provides an avenue by which to predict and ultimately prevent widespread outbreaks. A wide variety of modeling tools have been used in the study of the spread of diseases, including Ordinary Differential Equations, Partial Differential Equations, and Difference Equations. In this study, an agent-based model is used to study the spread and control of epidemics and is based on Sirakoulis, et al. [1]. The computer program NetLogo [2] is used for simulation. The development and set-up procedures for …


Probe Level Analysis Of Affymetrix Microarray Data, Richard Ellis Kennedy Jan 2008

Probe Level Analysis Of Affymetrix Microarray Data, Richard Ellis Kennedy

Theses and Dissertations

The analysis of Affymetrix GeneChip® data is a complex, multistep process. Most often, methodscondense the multiple probe level intensities into single probeset level measures (such as RobustMulti-chip Average (RMA), dChip and Microarray Suite version 5.0 (MAS5)), which are thenfollowed by application of statistical tests to determine which genes are differentially expressed. An alternative approach is a probe-level analysis, which tests for differential expression directly using the probe-level data. Probe-level models offer the potential advantage of more accurately capturing sources of variation in microarray experiments. However, this has not been thoroughly investigated, since current research efforts have largely focused on the …


Characterization Of Microorganisms Of Interest To Homeland Security And Public Health Utilizing Liquid Chromatography/Mass Spectrometry, Robert A. Everley Jan 2008

Characterization Of Microorganisms Of Interest To Homeland Security And Public Health Utilizing Liquid Chromatography/Mass Spectrometry, Robert A. Everley

Theses and Dissertations

Liquid chromatography/quadrupole time of flight mass spectrometry (LC/QTOF MS) utilizing electrospray ionization was employed to monitor protein expression in Escherichia coli and Shigella organisms. Automated charge state deconvolution, spectral subtraction and spectral mirroring were used to reveal subtle differences in the LC/MS data. Reproducible intact protein biomarkers were discovered based on their unique mass, retention time and relative intensity. These markers were implemented to differentiate closely related strain types, (e.g. two distinct isolates of E. coli O157:H7) and to correctly identify unknown pathogens. Notable, was the distinction of multiple serotypes of enterohaemorrhagic E. coli which cannot be distinguished by clinical …


Properties And Recent Applications In Spectral Graph Theory, Michelle L. Rittenhouse Jan 2008

Properties And Recent Applications In Spectral Graph Theory, Michelle L. Rittenhouse

Theses and Dissertations

There are numerous applications of mathematics, specifically spectral graph theory, within the sciences and many other fields. This paper is an exploration of recent applications of spectral graph theory, including the fields of chemistry, biology, and graph coloring. Topics such as the isomers of alkanes, the importance of eigenvalues in protein structures, and the aid that the spectra of a graph provides when coloring a graph are covered, as well as others.The key definitions and properties of graph theory are introduced. Important aspects of graphs, such as the walks and the adjacency matrix are explored. In addition, bipartite graphs are …


Reducing Bacterial Resistance Through Better Antibiotic Prescription Practices, Christine Ouma Jan 2008

Reducing Bacterial Resistance Through Better Antibiotic Prescription Practices, Christine Ouma

Theses and Dissertations

The objective of this study was to find a regression procedure that can better explain the relationship between patterns of antibiotic use and proportions of bacterial resistance. The sample for the study is comprised of 44 University Health System Consortium (UHC) member hospitals, and the data for antibiotic use and proportions of resistance are from the years 2002 to 2005. The hospitals are spread across the Northeast, South, Southwest, Midwest, and Northwest regions of the USA. Based on statistical analysis, MRSA continues to have the highest proportion of resistance among the bacteria examined and has increased significantly since 2002. The …


Magnetic Nanoparticles Based On Iron: Synthesis, Characterization, Design, And Application, Michael David Shultz Jan 2008

Magnetic Nanoparticles Based On Iron: Synthesis, Characterization, Design, And Application, Michael David Shultz

Theses and Dissertations

Magnetic nanoparticles are of great interest for a wide range of applications. This work has focused on three primary forms of iron based nanoparticles and combinations thereof: α-iron, iron oxide, and iron carbide or cementite. The synthesis of several core-shell particles including cementite-iron oxide, α-iron-cementite, and α-iron-iron oxide was accomplished through reverse micelle routes and high temperature decomposition of iron pentacarbonyl in various media. Structural analysis to confirm the structures was performed using extended x-ray absorption fine structure (EXAFS) techniques. A rapid characterization technique was developed utilizing a correlation between Fourier transform infrared spectroscopy and EXAFS to determine the full …