Physical Sciences and Mathematics Commons^™

High Pressure Effects On Electron Transport And Structure Of Colossal Magnetoresistive Materials, Congwu Cui

Dissertations

Pressure effects on the electronic, magnetic properties and structure of several typical colossal magnetoresistive manganites, La_0.60Y_0.07Ca_0.33MnO₃, Pr_1-xCa_xMn0₃ (X = 0.25, 0.30, 0.35), Nd_1-xSr_xMnO₃ (x = 0.45, 0.50), were explored through high pressure resistivity and structure measurements. It was shown that pressure up to ~7 GPa induces more complicated charge, spin and lattice state changes than in the low pressure range explored previously. In La_0.60Y_0.07Ca_0.33MnO₃, pressure induces a local atomic structure transformation at a critical …

Pharmacophore Derivation Using Discotech And Comparison Of Semi-Emperical, Ab Initio And Density Functional Comfa Studies For Sigma 1 And Sigma 2 Receptor-Ligands, Dawoon Jung

Dissertations

This study describes the development of pharmacophore and CoMFA models for sigma receptor ligands. CoMFA studies were performed for 48 bioactive sigma 1 receptorligands using [H³ ](+) pentazocine as the radioligand, for 30 PCP derivatives for sigma 1 receptor-ligands using [³H](+)SK-F 10047 as the radioligand and for 24 bioactive sigma 2 receptor-ligands using the radioligand [H³](+)DTG in the presence of pentazocine. Distance Comparisons (DISCOtech) was used as the starting point for CoMFA studies. The conformers, derived by DISCOtech were optimized using AMi, or HF/3-21G* in Gaussian 98. The optimized geometries were aligned with the pharmacophore, …

Nonlinear Optical Properties Of Novel Nanostructured Ion Implanted Laser Ablated Silicon Using Femtosecond Pulse Excitation, Elaine Nicole Lalanne

Dissertations

The study of the nonlinear optical properties of novel nanostructured ion implanted and laser ablation of Silicon is motivated by the need for materials that exhibit large values of the real part of the third order nonlinear susceptibility (χ⁽³⁾_Re). This property is essential for light controlled phase or refractive index modulation at low power, where the optical properties are used for optical switching devices. Previous nanosecond (ns) measurements indicated values of-2.8 x 10 ^-5; esu ( γ = 532 nm) for χ⁽³⁾_Re.

The characterization of nonlinear optical properties of the samples was studied …

Image Enhancement Techniques Applied To Solar Feature Detection, Artur J. Kowalski

Dissertations

This dissertation presents the development of automatic image enhancement techniques for solar feature detection. The new method allows for detection and tracking of the evolution of filaments in solar images. Series of H-alpha full-disk images are taken in regular time intervals to observe the changes of the solar disk features. In each picture, the solar chromosphere filaments are identified for further evolution examination. The initial preprocessing step involves local thresholding to convert grayscale images into black-and-white pictures with chromosphere granularity enhanced. An alternative preprocessing method, based on image normalization and global thresholding is presented. The next step employs morphological closing …

Application Of Adaptive Optics To The Spectroscopic Investigation Of Small-Scale Solar Structures, Klaus Hartkorn

Dissertations

We study bright points, umbral dots and the G-band using a two-dimensional spectrometer and an Adaptive Optics system, which allows us to record high-resolution dopplergrams and residual intensity images. We find evidence that bright points are smaller than 120 km in diameter. Bright points are situated exclusively in regions of enhanced G-band brightness and do not show a change in their shape or a displacement in their position of more than 120 km horizontally over a height range from 0 km to 320 km above photospheric level T = 1. We do not find velocity differences of more than 100 …

The Inverse Problem: Christianity Through A Mathematical Lens, Sharon K. Robbert

ACMS Conference Proceedings 2003

An inverse problem is a partner problem that reverses some type of direct problem. Usually the inverse problem is more challenging to solve than the direct problem: integration is more challenging than differentiation, factoring large numbers is more challenging than multiplying numbers. In this paper, the author poses that using mathematical thinking to understand the concepts of theological principles is the direct problem to the much more challenging inverse problem of using theological thinking to influence understanding in mathematics. Acknowledging that a problem is difficult allows one to be satisfied with understanding small pieces and progressing slowly to a complete …

The Search For The Real Josephus Problem, Eric Gossett

ACMS Conference Proceedings 2003

Many of the problems that mathematicians and computer scientists dearly love have been around for a long time. One such problem is known as the Josephus Problem, named after the first century Jewish historian Flavius Josephus. Josephus did not invent the problem. Instead, an event from his life served as the inspiration for the problem statement. Many current books refer to "Mathematical Recreations and Essays" by W. W. Rouse Ball [originally published in 1892] for the problem statement. The problem is quite interesting (and will be solved here). However, the story, as quoted in Bell, is not completely accurate.

A Greater Tantalizer, Andrew Simoson

ACMS Conference Proceedings 2003

The children’s puzzle, sometimes called the Great Tantalizer, consists of four blocks each of whose faces have been colored with four colors; a solution consists in stacking the blocks so that on each stack face, all four colors appear. This article renders the puzzle as six octahedral blocks, each of which is colored with six colors, and describes a scheme to successfully stack all six.

What Is A Random Event? A Project For Finite Math Or Statistics, Jeremy Case

ACMS Conference Proceedings 2003

Randomization is an important idea in Finite Mathematics and Statistics. One main idea in these courses is that events that appear to be performed in a random fashion are often not random. Here we present a simple project involving "randomly" opening the Bible. This activity leads to deeper philosophical questions such as how to study the Bible and whether an event can be considered random if God intervenes.

Sos Checks And Career Management, Russell W. Howell

ACMS Conference Proceedings 2003

This paper compares the careers of King Saul and King David in the Bible and how they inform the career management methods of a Christian.

Mathematical Models And Reality, John Byl

ACMS Conference Proceedings 2003

This paper examines the nature and function of mathematical models, using illustrations from cosmology, space geometry and atomic physics. Mathematical models enable us to make precise calculations and predictions; they serve as analogies and conceptual frameworks that lead to new discoveries; and they bridge the gap between appearance and reality. Their success implies that the universe had a mathematical structure. However, one must be careful not to confuse models of reality with reality itself. A variety of models can represent the same data; any model can be given different physical interpretations. The choice of a model and its interpretation depends …

Integrating Laptops Into A Mathematics Curriculum, Mary Wagner-Krankel

ACMS Conference Proceedings 2003

In 1999, St. Mary's University in San Antonio received a Title V Grant, providing $2.1 million over five years. The money was used to help finance computers for students, fund faculty training for computer-related curriculum, convert traditional classrooms into technology or "Smart classrooms", and upgrade the school's Internet connections. This article discusses specific software and hardware advancements made at the University through this grant. The article also describes how the Math department specifically integrated the laptops into their courses using software programs such as Mathcad and Blackboard.

Linear Regression As A 1-Variable Optimization Exercise, Ken Constantine

ACMS Conference Proceedings 2003

Derivation of the least squares line for a set of bivariate data entails minimizing a function of two variables, say the line's slope and intercept. Imposing the requirement that the line pass through the mean point for the data reduces this problem to a 1-variable problem easily solved as a single-variable Calculus exercise. The solution to this problem is, in fact, the solution to the more general problem. We illustrate with a dataset involving charitable donations.

Exploiting The Confidence Interval-Hypothesis Test Equivalence In Basic Statistics Classes, Ken Constantine

ACMS Conference Proceedings 2003

An emphasis is offered for the inference portion of an elementary Statistics course: the equivalence between confidence intervals and tests of hypotheses. This equivalence is rarely mentioned in basic texts but seems helpful to students. Student reference sheets which employ this equivalence are available on-line.

A Christian Appraisal Of Stephan Wolfram's A New Kind Of Science, Gene B. Chase

ACMS Conference Proceedings 2003

Wolfram exposes some ideas about informatics that relate to Christian Scholarship: Does Wolfram's definition of free will permit God to have free will? Will human souls resurrected to a new body–as described by St. Paul and Aquinas–by like software that is moved to new hardware? Jesus' incarnation as in-form-ation in the Aristotelian sense.

Creationism - A Viable Philosophy Of Mathematics, Jonathan Zderad

ACMS Conference Proceedings 2003

The purpose of this essay is to try to answer the ontological and epistemological question of mathematics. Specifically, "What, if any, of mathematics exists in the objective sense?" And, "How do we as humans know that our knowledge of mathematics is correct?" These questions will be investigated by looking at the applications or mathematics, the practice of mathematicians, and most telling, the content of mathematics. Mathematics, admittedly, can only go so far in answering its own philosophical questions, even when aided by recent developments in the field of logic. The overwhelming evidence, as will be shown, points toward a theistic, …

An Application In Bioinformatics : A Comparison Of Affymetrix And Compugen Human Genome Microarrays, Milind Misra

Theses

The human genome microarrays from Compugen® and Affymetrix® were compared in the context of the emerging field of computational biology. The two premier database servers for genomic sequence data, the National Center for Biotechnology Information and the European Bioinformatics Institute, were described in detail. The various databases and data mining tools available through these data servers were also discussed. Microarrays were examined from a historical perspective and their main current applications-expression analysis, mutation analysis, and comparative genomic hybridization-were discussed. The two main types of microarrays, cDNA spotted microarrays and high-density spotted microarrays were analyzed by exploring the human genome microarray …

Making Connections: Using Analogies To Enrich Understanding Of Mathematical Ideas And Biblical Truths, Ron Benbow

ACMS Conference Proceedings 2003

Recent standards and research, published by mathematics education professional organizations, place a great emphasis on “connections” in all grade levels. Through this emphasis on interrelatedness, students begin to see the subject not as a collection of separate strands, but rather as an integrated field of study. When linkages between diverse domains of knowledge are formed (by comparing, contrasting, analyzing, and applying), we have increased the likelihood that we develop deeper understandings within both domains. This paper explores some specific examples of the use of analogies to connect mathematical and Biblical concepts.

Mathematics, Science, And George Macdonald, David L. Neuhouser

ACMS Conference Proceedings 2003

In writing about George MacDonald choosing a college major, biographer William Raeper wrote that he chose “chemistry, a strange choice perhaps for a future novelist and poet and not an easy one for him to make.” He further conjectured that MacDonald’s choice was based on “common sense and sound economics” rather than “his poetic yearnings.” Many would agree with Raeper that science is a strange choice for a future poet and novelist. This paper argues that the role of beauty and imagination is very similar in science, mathematics, and literature, so it might not be so strange that someone could …

Men Are From The Server Side, Women Are From The Client Side: A Biblical Perspective On Men, Women And Computer Science, Kim Potter Kihlstrom

ACMS Conference Proceedings 2003

The percentage of women in computer science is small and has decreased over the last twenty years. Why is this the case, when computer science is a wonderful and growing field with many opportunities? I believe that the situation has its roots in the basic differences between men and women, differences that were present from the beginning of creation and are a part of the way that God made male and female uniquely. In order to ensure that both talented men and women are attracted to computer science, we need to understand the differences between men and women, and how …

Evaluation Of Fluorapatite As A Waste-Form Material: Third Quarter Report, March 1 - May 31 2003, Dennis W. Lindle, Dale L. Perry

Separations Campaign (TRP)

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF₄, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form …

Fresh Kills Dumped : A Policy Assessment For The Management Of New York City's Residential Solid Waste In The Twenty-First Century, Aaron William Comrov

Theses

New York City ceased disposing of its daily residential solid waste output within its municipal borders in March 2001 when the Department of Sanitation completed its phase-down of the Fresh Kills landfill on Staten Island. The closure of this facility has, for the first time in history, stripped New York City of its waste management selfsufficiency, created a situation in which municipal officials are reliant on private firms and other governmental jurisdictions for disposal services, and contributed to deteriorating fiscal, environmental, political, economic, social and practical conditions.

Consequent and concurrent to this predicament, a multitude of alternative policies have been …

The Rationale For Preserving Neighborhood Open Space In Newark, New Jersey's North Ward, Stephen M. Wiessner

Theses

A study was conducted to determine the shifts in open space availability between 1950 and 2003 in four neighborhoods in the North Ward of Newark, New Jersey. Total open space in square feet and open spaces ten thousand square feet and less were quantified to determine the extent of usable open space for the creation of community gardens or vest pocket parks.

The study identified large reductions of open space recently in the two least affluent study areas. The two more affluent study areas have also lost open space recently, but not at the magnitude of the poorer study areas. …

Feedback Algorithm For Switch Location : Analysis Of Complexity And Application To Network Design, Yuriy S. Polyakov

Theses

An accelerated feedback algorithm to solve the single-facility minisum problem is studied with application to designing networks with the star topology. The algorithm, in which the acceleration with respect to the Weiszfeld procedure is achieved by multiplying the current Weiszfeld iterate by an accelerating feedback factor, is shown to converge faster than the accelerating procedures available in the literature. Singularities encountered in the algorithm are discussed in detail. A simple practical exception handling subroutine is developed. Several applications of the algorithm to designing computer networks with the star topology are demonstrated. Applications of the algorithm as a subroutine for multi-switch …

Towards Digital Library Service Integration, Prateek Shrivastava

Theses

Digital Library Service Integration (DLSI) aims to provide a systematic approach in integrating the services and collections of National Science and Digital Library. The National Science and Digital Library collections can share the services among themselves in a totally integrated environinent. Collections as such will require no change to plug into the DLSI architecture. Collections will keep using the services of NSDL in the similar manner as before. These services will in turn pass few parameters to the services of DLSI. With the help of these parameters, wrappers will fetch the details and priority of the users. These wrappers will …

Uber-Claws : Unsupervised Pattern Classification For Multi-Unit Extracellular Neuronal Burst Extraction, Rama Natarajan

Theses

To further an understanding of how a neuronal population generates patterns of rhythmic activity, the temporal dynamics of the group of neurons must be formalized. Essential to this pursuit, is the ability to reliably detect and separate the classes of single-unit neuronal activity from multi-unit extracellular signals recorded in a single channel. This study proposes a unified approach to automatically detect and classify single-unit bursts, and to observe the precise onset and offset of burst activity. Existing approaches to the problem fundamentally depend on the statistics of spike waveform variability, both extrinsic and intrinsic to the neuron. In contrast, the …

Rnase L Mediates Transient Control Of The Interferon Response Through Modulation Of The Double-Stranded Rna-Dependent Protein Kinase Pkr, Khalid S.A. Khabar, Yunus M. Siddiqui, Fahad Al-Zoghaibi, Latifa Al-Haj, Mohammed Dhalla, Aimin Zhou, Beihua Dong, Mark Whitmore, Jayashree Paranjape, Mohammed N. Al-Ahdal, Futwan Al-Mohanna, Bryan R.G. Williams, Robert H. Silverman

Chemistry Faculty Publications

The transient control of diverse biological responses that occurs in response to varied forms of stress is often a highly regulated process. During the interferon (IFN) response, translational repression due to phosphorylation of eukaryotic initiation factor 2α, eIF2α, by the double-stranded RNA-dependent protein kinase, PKR, constitutes a means of inhibiting viral replication. Here we show that the transient nature of the IFN response against acute viral infections is regulated, at least in part, by RNase L. During the IFN antiviral response in RNase L-null cells, PKR mRNA stability was enhanced, PKR induction was increased, and the phosphorylated form of eIF2α …

Spade: Spki/Sdsi For Attribute Release Policies In A Distributed Environment, Sidharth P. Nazareth

Dartmouth College Master’s Theses

Shibboleth is a federated administrated system that supports inter-institutional authentication and authorization for sharing of resources. SPKI/SDSI is a public key infrastructure whose creation was motivated by the perception that X.509 is too complex and flawed. This thesis addresses the problem of how users that are part of a Public Key Infrastructure in a distributed computing system can effectively specify, create, and disseminate their Attribute Release Policies for Shibboleth using SPKI/SDSI. This thesis explores existing privacy mechanims, as well as distributed trust management and policy based systems. My work describes the prototype for a Trust Management Framework called SPADE (SPKI/SDSI …

Electronic Documents And Digital Signatures, Kunal Kain

Dartmouth College Master’s Theses

Often, the main motivation for using PKI in business environments is to streamline workflow, by enabling humans to digitally sign electronic documents, instead of manually signing paper ones. However, this application fails if adversaries can construct electronic documents whose viewed contents can change in useful ways, without invalidating the digital signature. In this paper, we examine the space of such attacks, and describe how many popular electronic document formats and PKI packages permit them.

Cool Temperatures Elicit Reproduction In A Biologically Invasive Predator, The Brown Treesnake (Boiga Irregularis), Tom Mathies, Lowell A. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Two different temperature regimes for eliciting reproduction in male and females of the Guam form of the brown treesnake were investigated. Males and females maintained at 24°C followed by a 60-day cool period at 19°C exhibited substantial reproductive activity, and the females that produced clutches did so during a brief period after return to 24°C. In contrast, individuals maintained at 28°C followed by an identical 19°C cooling period exhibited relatively little reproductive activity, and although some females became vitellogenic, none produced eggs. Reproductive activity was virtually absent in all individuals in both groups 7 months after the end of the …