Physical Sciences and Mathematics Commons^™

A Comparison Of Different Schemes For Selecting And Estimating Score Functions Based On Residuals, Ali A. Al-Shomrani

Dissertations

In a linear model when the errors follow a normal distribution, least squares methodology is most powerful. However, when the assumption of normality of the error distribution is not met then there exist methods which are more powerful than least squares methods. Rank-based methods form one such class. These methods depend on the selection of a score function [varphi]( u ). The correct choice of [varphi] leads to an optimal (efficient) analysis, but its selection depends on the error distribution which is not known.

In this thesis, we explore different schemes for score selection. Some of these schemes are functions …

Stratigraphy Of Lake Michigan Lobe Deposits In Van Buren County, Michigan, Steven P. Beukema

Masters Theses

The surficial glacial deposits and landforms of Van Buren County were recently mapped at a 1:24,000 scale as part of a STATEMAP project. Several borings were drilled to supplement the surface data. Six of these borings were characterized in detail by means of gamma ray logging, textural analysis, and X-ray diffraction of the clay-sized fraction of the diamicton units.

Results from this study reveal two diamicton units at stratigraphically distinct positions that can be correlated across the county and that are separated by a thick sequence of lacustrine sediments. Correlation of diamicton and lacustrine units was accomplished by analyzing several …

Optical Solitons In A Three-State Medium, Talal Ghannam

Masters Theses

When a beam of light propagates within a typical medium, absorption is a common phenomenon. This happens when the frequency of the light is close to a resonant frequency of the atoms composing the medium. But in the past few decades, it has been shown that in certain circumstances, carefully chosen pulse shapes are able to propagate without significant absorption even when the frequency of the light is close to an atomic resonant frequency. It was called Self Induced Transparency (SIT).

This phenomenon was intensively studied in the two-state systems. On the other hand, the three-state systems seems not to …

New Graphical Approach On The Analysis Of Experimental Data, Suha Sari

Dissertations

This study presents a new graphical method to identify significant effects in factorial experiments. The proposed methods are obtained for the different cases in which the design can be of full factorial or fractional factorial and the factor levels can be pure or mixed.

We focus on the different decomposition methods, for example orthogonal components system and orthogonal contrast method, to make use of the chisquare plot which requires that the sums of squares are of the same degrees of freedom. Examples and simulations illustrating the different cases of the procedure are presented.

A Geochemical Survey Of The Natural Waters Of Belize, Central America, Anthony D. Marfia

Masters Theses

A geochemical survey of the natural waters in Belize, Central America was carried out to compliment routine water quality analysis and to identify processes affecting water quality. The objective of this research was to provide a geochemical assessment of natural waters throughout Belize by examining select major ions (Ca²⁺, Mg²⁺ , SO₄^2-), and stable isotopes of carbon (¹³C), oxygen (¹⁸O) and hydrogen (²H).

The dominant geology relevant to this investigation comprises a varied landscape of carbonates and elastic sediments in a subtropical rainforest/savannah climate. Stable oxygen and hydrogen …

Development Of Kohonen Neural Network Application As A Pattern Recognition System For An Electronic Nose, Lori Lynn Evesque

Masters Theses

Electronic noses are used to identify and characterize unknown odors in industry. Chemometrics and neural network algorithms are used as pattern recognition systems for these devices. Experimentation with Kohonen clustering as the pattern recognition system for electronic noses was not noted prior to 1997. [BEG] This thesis investigated the use of a Kohonen neural network algorithm as a clustering algorithm for electronic nose data using the chemometrics algorithms built into the electronic nose as a performance standard. A secondary aim was to improve the clustering and identification capabilities of the Kohonen network.

The unsupervised Kohonen network was not able to …

The Tragedy Of The Rivers: Building Authority Over The British Water Environment, Kevin B. Vichcales

Dissertations

"The Tragedy of the Rivers: Building Authority over the British Water Environment" examines the problem of rivers as common public resources in modern Britain. Viewed historically, the enduring problem of environmental pollution control in Britain has been the establishment of regulating authority over aspects of nature that are regarded simultaneously as economic resources, public utilities, and public amenities. Legislators, subject to pressure from industrial polluters, political parties, and advocates for environmental quality, sought at different times to locate authority at local, regional, national and extra-national levels. Each effort failed to resolve the issue of authority over the environment, because administrative …

Multiobjective Optimal Control Problems With Endpoint And State Constraints, Kirsty J. Eisenhart

Dissertations

In this thesis we consider nonsmooth multiobjective optimal control problems in terms of a general preference on [Special characters omitted.]. The optimal control problems considered involve differential inclusion, endpoint constraints and state constraints. No convexity assumption is needed on the differential inclusion. Examples of common preferences are given, and the idea of approximating a preference is introduced. Euler-Lagrange necessary conditions and a form of the maximum principle are developed for closed preferences (and those that can be approximated by closed preferences) in terms of the limiting subdifferential. As a consequence, this is the first result in the literature for lexicographical …

Physics Department News, February 2003, College Of Arts And Sciences

Physics Newsletter

Contents from Volume 2, Issue 1:

• A Word From the Present Chair
• A Word From the Past Chair
• What’s New at the University
• Faculty Highlights
• PhysTEC
• New Faculty
• Alumni News
• Alumni Achievement Awards
• Annual Student Awards
• Recent Graduates
• Recent Guests
• Department Roster
• Photo Gallery
• Feedback/Update Reply Form

On Rank-Based Considerations For Generalized Linear Models And Generalized Estimating Equation Models, Diana R. Cucos

Dissertations

This study discusses rank-based robust methods for estimation of parameters and hypotheses testing in the generalized linear models (GLM) and generalized estimating equations (GEE) setting. The robust estimates are obtained by minimizing a Wilcoxon drop in dispersion function for linear or nonlinear regression models. In addition, diagnostic tools for outliers and influential observations are being developed. These models are generalizations of linear and nonlinear models. They allow for both nonlinear mean functions and heteroscedasticity of their random errors. This makes them quite useful in practice. Rank-based inference has been developed for linear models over the last thirty years. This inference …

Robust Residuals And Diagnostics In Autoregressive Time Series, Kirk W. Anderson

Dissertations

One of the goals of model diagnostics is outlier detection. In particular, we would like to use the residuals, appropriately standardized, to “flag” outliers. Hopefully, our (robust) procedure has yielded a fit that resists undue influence by outlying points, while simultaneously drawing attention to these interesting points via residual analysis. In this study we consider several different methods of standardizing the residuals resulting from autoregression. A large sample approximation for the variance of rank-based first order autoregressive time series residuals is developed. This provides studentized residuals, specific to the time series model and estimation procedure. Simulation studies are presented that …

Load Balancing And Congestion Avoidance Routing, Konstantinos N. Kokkinos

Dissertations

Today’s high speed backbone networks are expected to support a wide range of communication-intensive applications. One of the most important issues in Quality of Service (QoS) is efficient routing. Many QoS routing solutions have been published lately for different criteria of QoS requirements and resource constraints. In this dissertation we focus on the design of regular network topologies and suggest efficient routing schemes to reduce the probability of hot spot creation in the network. Furthermore, we provide a detection of congestion mechanism that reroutes traffic to maintain balancing with small communication cost. Several theoretical results relatively to network traffic balancing …

Geoelectrical Response Of An Aged Lnapl Plume: Implications For Monitoring Natural Attenuation, Douglas D. Werkema Jr.

Dissertations

The geoelectric stratigraphy at a site impacted with light non-aqueous phase liquids (LNAPLs) is investigated for its link to natural biodegradation, its contribution to the conductive model for aged (i.e. mature) LNAPL contaminated sites, and the relationship to the natural hydrologic regime. The highest conductivities (lowest resistivities) were observed in portions o f soils where LNAPL was in residual and free phase. Corroborating evidence from bacteria enumeration from soil close to the vertical resistivity probe (VRP) installations show orders-of-magnitude increase in both heterotrophic and oil degrading microbes at the depths where the conductivity was at a maximum. The coincidence o …

Integrated Geophysical Examination Of A Former Refinery Site, Carson City, Michigan, Kennedy Opiyo Mwanda

Masters Theses

Integrated geophysical surveys, including electromagnetic (EM-31), magnetic, dc resistivity, and ground penetrating radar (GPR) methods and soil borings were used to investigate part of a former refinery site in Carson City, Michigan, which has more than a 50-year history of hydrocarbon contamination.

Although not readily evident on the magnetic anomaly maps, the EM-31 conductivity map clearly revealed many sections of buried pipes of various lengths and orientations. Also evident on the EM maps are extensive near surface conductivity anomalies. Soil borings in zones of anomalous conductivities to the west suggest the presence of shallow clays with pooled hydrocarbons at depths …

Mechanistic Studies On The Antagonistic Effect Of Chromium On Bpde Mutant Frequency In Human Fibroblasts, Felicia Codrea

Masters Theses

The purpose of this study was to investigate the possible mechanisms involved in the decrease in mutant frequency when cells are treated with two different types of carcinogens: chromium (VI) in combination with benzo(a)pyrene diol epoxide (BPDE). Three of our working hypotheses are: Cr alone or Cr and BPDE synergistically activate detoxifying enzyme glutathione-S-transferase (GST), Cr alone or Cr and BPDE act synergistically to inhibit cell cycle at the G₁/S boundary thus allowing more time for DNA repair, and Cr alone or Cr and BPDE synergistically activate DNA repair systems which result in more efficient repair of DNA …

Microbial Community Structure In Hydrocarbon Impacted Sediment Associated With Anomalous Geophysical Signatures, Joseph W. Duris

Masters Theses

The Crystal Refinery is a former refinery site in Carson City Michigan that has had historic releases of refined and unrefined crude oil dating back to the late 1940's. The contamination of soil with light non-aqueous phase liquids (LNAPL) has had a dynamic impact on the subsurface environment in adjacent Carson City Park. Very little is known about the complex interactions between microbial communities, geochemistry and geophysics. In order to investigate possible connections between these parameters a multidisciplinary study was undertaken to investigate the hypothesis that the degradation of LNAPL by resident microbial communities causes a local increase in organic …

Inorganic And Organic Chemistry Of The Former Lakeside Refinery In Kalamazoo, Michigan, Kurt W. Carlson

Masters Theses

The focus of this investigation of the Lakeside Refinery site is the inorganic geochemistry because previous investigations concerned organics and heavy metals. Because little nitrate is in native groundwater, high dissolved ammonia immediately downgradient from a petroleum body suggests the source is the petroleum and/or associated byproducts. Iron reduction is most prominent immediately upgradient from the known and measurable petroleum while manganese reduction occurs mostly downgradient. Sulfate reduction occurs mostly towards the southern portion of the light petroleum LNAPL. Based on concentrations of nitrate, manganese, iron and sulfate along a groundwater flow path, there appears to be a sequential use …

Geochemical And Isotopic Characteristics Associated With High Conductivities In A Shallow Hydrocarbon-Contaminated Aquifier, Franklyn D. Legall

Dissertations

In-situ vertical resistivity probes (VRPs) deployed at a hydrocarboncontaminated site in SW Michigan showed high soil conductivities within the contaminated zone. Within this zone, different phases of hydrocarbon impact were recognized, namely, zones with residual and dissolved phase hydrocarbons (RDH) and zones where these phases coexist with free product (RDFH). Bulk soil conductivities were highest ( 12 to 30 mS/m) in the zone with RDFH compared to the RDH zone (10 to 25 mS/m). Groundwater chemistry and stable carbon isotope data from closely spaced vertical samples within the anomalous conductive zones were used to provide evidence for biodegradation and to …

Resolvability In Graphs, Varaporn Saenpholphat

Dissertations

The distance d (u, v ) between two vertices u and v in a connected graph G is the length of a shortest u - v path in G . For an ordered set W = { w1 , w2 , [Special characters omitted.] &cdots; , wk } of vertices in G and a vertex v of G , the code of v with respect to W is the k -vector cW (v ) = (d ( v, w1 ),d (v, w 2 ), [Special characters omitted.] &cdots; , d …

New Statitstical Methods For The Estimation Of The Mean And Standard Deviation From Normally Distributed Censored Samples, Abou El-Makarim Abd El-Alim Aboueissa

Dissertations

The main objective of this dissertation is to estimate the mean /x and standard deviation cr of a normal population from left-censored samples. We have developed new methods for calculating estimates for the mean and standard deviation of a normal population from left-censored samples. Some of these methods based on traditional estimating procedures. A new method of obtaining the Cohen maximum likelihood estimates for fx and cr without the aid of an auxiliary table will be introduced. This new method will be used to extend Cohen table of estimating the Cohen A-parameter that is required for calculating the maximum likelihood …

Geosciences Newsletter- 2002, Department Of Geosciences

Geological and Environmental Sciences News

Vol.1, No. 27

• Dear Alumni and Friends
• Faculty News
• Department News
• Core Lab
• Geosciences Departmental History
• Graduate Student News
• Awards & Graduations
• Alumni News
• Donations

Visualization Methods: A Comparative Study Of New, Traditional And Robust Procedures, Kimberly Crimin

Dissertations

Two major goals in discriminant analysis are discrimination and classification. In discrimination, the goal is to describe graphically (visualization) different features of several known groups. In classification, the goal is to allocate unknown observations to one of several known groups. We have developed new visualization procedures based on traditional estimating procedures and also on robust estimating procedures. We have further developed robust classification procedures. We propose several robust classification procedures based on coordinatewise and affine equivariant, rank-based robust estimates. Empirical studies are performed over many different error distributions. These studies result in empirical efficiencies of the robust and traditional procedures. …

Electron Correlation Leading To Double-K-Shell Vacancy Production In Li-Like Ions Colliding With Helium, Ali Sami Alnaser

Dissertations

Single and double K-shell vacancies in Li-like ions colliding with neutral helium target have been investigated using high-resolution Auger projectile spectroscopy. Be⁺, B²⁺, C³⁺, and O⁵⁺ Li-like ions were produced and accelerated to intermediate-to-high collision velocities where perturbative models are expected to be valid, using the Tandem Van de Graaff accelerator at Western Michigan University. Double-K-shell vacancies in atomic systems or so-called “ hollow ions” can be induced by different mechanism in ion-atom collisions. For intermediate-to-high velocity collisions where the collision time is small, the projectile ion can interact with only one of …

A New Type Of Particle Detector For Nuclear Scattering Experiments, Philip Ugorowski

Dissertations

A new detector was needed for counting recoil protons resulting from proton-proton (pp) elastic scattering during pion production experiments by the Polarized Internal Target Experiments (PINTEX) group at Indiana University Cyclotron Facility (IUCF). The previous silicon detectors were only usable forincoming protons up to 9 MeV, and a stopping power of at least 40 MeV was needed. In addition, the detector had to operate in nanotorr vacuum, and near strong varying magnetic fields, ruling out standard organic plastic scintillators and photomultiplier tubes. We needed to find the most suitable inorganic scintillator and another method of detecting the photons produced when …

Metal Ion Separation Mediated By Organized Molecular Assemblies, Hong Cao

Masters Theses

We have investigated the separation of Co(II), Ni(II), Cu(II) and Zn(II) by the ligands 8-hydroxyquinoline- 5-sulfonic acid and 7-iodo-8-hydroxy-quinoline- 5-sulfonic acid in the presence of the anionic surfactant sodium dodecyl sulfate (SDS) and the cationic surfactant octyltrimethylammonium bromide (OTAB) . Baseline separations have been achieved by HPLC employing an octadecylsilanized silica (ODS) column. The underlying mechanisms of separation have been determined.

The significant new results of our studies are: (1) separation is not possible without the presence of surfactants and hence organized assemblies; (2) separations can be achieved under submicellar concentrations; (3) the separations are not driven by micelles; and …

Separable Preference Orders, Jonathan K. Hodge

Dissertations

Whenever a decision-maker must express simultaneously his or her preferences on several possibly related issues, the existence of interdependence among these preferences can lead to collective decisions that are unsatisfactory or even paradoxical. Intuitively, an individual’s preferences are said to be separable on a subset of issues if they do not depend on the choice of alternatives for issues outside the subset. Here we explore from a mathematical standpoint the properties of separable and nonseparable preference orders. We begin by formulating a general model of multidimensional preferences and we formally introduce the notions of separability and noninfluentiality. We study the …

Multiple Isotopic Investigation Of Lake Sediments From Northern India, Alice Mwanda

Masters Theses

Stable isotopes ratio of lake sediments can provide valuable environmental information. This possibility has been investigated using radiocarbon dated fossil lake sediments from the Himalayan region of Northern India. The chronology was established using Radiocarbon dating of both organic and inorganic fractions using (AMS). Inorganic ages are older than organic ages. Organic ages are expected to increase stratigraphically, however several anomalous old ages are found in the younger part of the sediments. Final chronology, determined using selected sensible ages identified two periods of sedimentation. The high sedimentation period is characterized by sedimentation rate of 0.8cm/yr and it fairly coincides with …

The Role Of Groundwater And Surface Water Interaction In The Development Of A 1,4-Dioxane Plume In Scio Township, Washtenaw County, Michigan, James W. Brode

Masters Theses

The purpose of this study was to examine the hypothesis that groundwater and surface water interaction resulted in the development a 1,4-dioxane plume in a glacial aquifer in Scio Township, Washtenaw County, Michigan.

An industrial solvent, 1,4-dioxane, was detected in the groundwater in the area of study in 1986. This area, referred to in this investigation as the Western Plume, is one of several 1,4-dioxane plumes associated with the Pall/Gelman Sciences Inc. (P/GSI) site, an extensively investigated site of groundwater contamination.

1,4-Dioxane in the Western Plume area was initially believed to be the result of contaminated groundwater transported from a …

Nonlinear Regression Based On Ranks, Ashebar Abebe

Dissertations

This study presents robust methods for estimating parameters of nonlinear regression models. The proposed methods obtain estimates by minimizing rankbased dispersions instead of the Euclidean norm. We focus on the Wilcoxon and generalized signed-rank dispersion functions. Asymptotic properties of the estimators are established under mild regularity conditions similar to those used in least squares and least absolute deviations estimation. The study also shows that by considering the generalized signed-rank dispersion we obtain a class of estimators that encompasses most of the existing popular nonlinear regression estimators. As in linear models, these rank-based procedures provide estimators that are highly efficient. This …

Improving The Campus Sustainability Assessment Process, Andrew Nixon

Honors Theses

The human enterprise is rapidly overwhelming the Earth’s ecological systems and draining its natural resources. According to Vitousek et al., as much as one-half of the planet’s land surface has been transformed by human activity; more than half of the world’s available fresh water is used by humans; and a quarter of the planet’s bird species have been driven to extinction by human activity (Vitousek et al, 1997). These and many other negative trends pose catastrophic implications for the future of our species and for the planet’s other inhabitants.