Physical Sciences and Mathematics Commons^™

A Resource Allocation Mechanism Based On Cost Function Synthesis In Complex Systems, Carlos C. Amaro

Dissertations

While the management of resources in computer systems can greatly impact the usefulness and integrity of the system, finding an optimal solution to the management problem is unfortunately NP hard. Adding to the complexity, today's 'modern' systems - such as in multimedia, medical, and military systems - may be, and often are, comprised of interacting real and non-real-time components. In addition, these systems can be driven by a host of non-functional objectives – often differing not only in nature, importance, and form, but also in dimensional units and range, and themselves interacting in complex ways. We refer to systems exhibiting …

Microwave Heating Of Fluid/Solid Layers : A Study Of Hydrodynamic Stability And Melting Front Propagation, John Gilchrist

Dissertations

In this work we study the effects of externally induced heating on the dynamics of fluid layers, and materials composed of two phases separated by a thermally driven moving front. One novel aspect of our study is in the nature of the external source, which is provided by the action of microwaves acting on dielectric materials. The main challenge is to model and solve systems of differential equations, which couple fluid dynamical motions (the Navie- Stokes equations for nonisothermal flows) and electromagnetic wave propagation (governed by Maxwell's equations).

When an electromagnetic wave impinges on a material, energy is generated within …

Emissivity Measurements And Modeling Of Silicon Related Materials And Structures, Sufian Abedrabbo

Dissertations

The objective of this dissertation is to investigate the major issues concerning applications of pyrometry for applications in rapid thermal processing (RTP) of silicon related materials. The research highlights of this work are:

Establishment of spectral ernissometry as a novel, reliable and reproducible technique for:

Determination of wavelength and temperature dependent reflectivity, transmissivity, emissivity and temperature, simultaneously, of silicon related materials and structures. The emissometer operates in the wavelength range of 1-20mm and temperature range of 300-1200K. The analysis of the influence of morphological effects on the radiative properties by measurement of (a) front-smooth incidence versus backside-rough incidence of singleside …

A Folder Organization Model For Information Systems : Exploring Its Architectural Expressive Power And Predicate-Based Filing, Simon Doong

Dissertations

This dissertation presents an Internal Folder Organization (I-ORG) which supplements the architectural deficiencies of the existing model - the User Folder Organization (U-ORG), to electronically model a person's filing system in the modern office environment. An I-ORG folder organization gives a logical representation of how documents of the same or different kinds are related and grouped into folders based on predefined premises. Our model is represented by a Rooted Direct Acyclic Graph (RDAG). Each node in the graph represents a folder; and folders are related by "subfolder relationship" (for capturing the "and" relation) and "virtual-folder relationship" (for capturing the "or" …

A Graph Based Process Model Measurement Framework Using Scheduling Theory, Gary Guang-Li Mou

Dissertations

Software development processes, as a means of ensuring software quality and productivity, have been widely accepted within the software development community; software process modeling, on the other hand, continues to be a subject of interest in the research community. Even with organizations that have achieved higher SEI maturity levels, processes are by and large described in documents and reinforced as guidelines or laws governing software development activities. The lack of industry-wide adaptation of software process modeling as part of development activities can be attributed to two major reasons: lack of forecast power in the (software) process modeling and lack of …

Angle-Resolved Studies Of Inner Shell Excitations For Argon, Krypton And Xenon Using Third Generation Synchrotron Sources, Ahmad H. Farhat

Dissertations

This dissertation, which is in the area of atomic physics, concentrates on the study of the interaction between VUV-soft X-ray radiation and atoms in the gas phase. The main area of interest is the study of Auger decay in atoms utilizing the process known as the resonance Auger effect, where an inner shell electron is excited to an unfilled orbital followed by the ejection of an Auger electron. The measurements in this thesis were performed by using the high resolution Atomic, Molecular and Optical Physics undulator beam line, which utilizes a spherical grating monochromator at the Advanced Light Source at …

A Generalization Of Cayley Graphs For Finite Fields, Dawn M. Jones

Dissertations

A central question in the area of topological graph theory is to find the genus of a given graph. In particular, the genus parameter has been studied for Cayley graphs. A Cayley graph is a representation of a group and a fixed generating set for that group. A group is said to be planar if there is a generating set which produces a planar Cayley graph. We say that a group is toroidal if there is a generating set that produces a toroidal Cayley graph and if there are no generating sets which produce a planar Cayley graph. Characterizations for …

Perturbed Hamiltonian System Of Two Parameters With Several Turning Points, Myeong Joon Ann

Dissertations

No abstract provided.

Units In Integral Group Rings For Direct Products, Richard M. Low

Dissertations

Given a finite group G and the ring of integers, one can form the integral group ring ZG . A natural problem to investigate is to find a description of the group of units for this ring ZG. Since the unit problem for integral group rings arises in the contexts of algebraic topology, number theory, and algebra, it is an important question to try to answer. For this reason, it has drawn the attention of researchers from diverse areas of mathematics.

Graham Higman (circa 1940) made substantial contributions to the solution of this problem, in the case where G was …

A Study Of The Knowledge Structure Of Expert, Intermediate, And Novice Subjects In The Domain Of Physics, Jennifer L. Discenna

Dissertations

The objective of this research was to investigate the knowledge structure in physics by describing the knowledge of experts, intermediates, and novices. A review of the literature on expertise, physics knowledge, and conceptual structure provided two competing representations of physics knowledge: one defined as a hierarchy of models arranged from general to specific models, the second defined by theories which link knowledge together.

In order to investigate the two representations described above, a reiterative categorization task was employed. This task resulted in a hierarchical sort with larger piles at the top of the hierarchy and smaller piles at the bottom …

Surface Models Of Finite Geometries, Ramon Manuel Figueroa-Centeno

Dissertations

The standard non-Euclidean geometries, hyperbolic geometry and elliptical geometry, both arise by negating the parallel postulate of Euclid. Both these geometries share with Euclidean geometries an infinitude of points and lines. But also possible are many finite geometries. Among these are the class of projective geometries PG(m,q) of projective dimension m (m > 2) and the k-configurations. These mathematical objects, although primarily geometric in nature, provide related structures of combinatorial interest: block designs. These have applications in scheduling problems and the design of experiments for statistical analysis. Recently, A. T. White has added a topological flavor to the study …

Electron Emission Following The Interaction Of Slow Highly Charged Ions With Solids, Joseph W. Mcdonald

Dissertations

The interaction of highly-charged ions with surfaces involves many excitation processes of the surface atoms and the bulk material. One such process, the emission of electrons from surfaces due to the potential energy of the incident ions has been studied. The experimental results presented here confirm that the majority of electrons emitted as a result of highly-charged ions interacting with a solid surface have energies of about 20 eV. Auger processes contribute a smaller fraction of the total emitted electrons with increasing Z o f the projectile. This contribution to the total electron emission yield is found to be less …

The Intelligent Browser For Texpros, Chih-Ying Wang

Dissertations

Browsing is a technique, which helps users to formulate their query and retrieve information in the information retrieval system. This technique provides users with capabilities of understanding their information needs and gaining system knowledge during the course of the browsing and thus it eases the users' burden when issuing queries. The basic components of the browser provides an underlying structure which allows users to navigate and a browsing process controller which provides users with the needed assistance during each browsing session.

In this dissertation, a new infrastructure (OP-Net), transformed from the existing object network is proposed. Each object in the …

Knowledge-Based Document Filing For Texpros, Xien Fan

Dissertations

This dissertation presents a knowledge-based document filing system for TEXPROS. The requirements of a. personal document processing system are investigated. In order for the system to be used in various application domains, a flexible, dynamic modeling approach is employed by getting the user involved in document modeling. The office documents are described using a dual-model which consists of a document type hierarchy and a folder organization. The document type hierarchy is used to capture the layout, logical and conceptual structures of documents. The folder organization, which is defined by the user, emulates the real world structure for organizing and storing …

A Paleoclimatic Study Of The Midwestern United States From The Stahle Isotope Records In Lake Sediments, Norman Alan Lovan

Dissertations

No abstract provided.

Groundwater Hydraulics And Slope Stability Analysis: Elements For Prediction Of Shoreline Recession, William W. Montgomery

Dissertations

Studies documenting the roles that geologic materials and groundwater play in Great Lakes bluff recession are rare. This study reports findings concerning relationships between bluff lithology, bluff hydrology, and bluff recession along a 10-mile stretch of eastern Lake Michigan shoreline in heterogeneous Pleistocene deposes. According to a newly-developed, field-tested, GIS-based methodology, bluffs in the study area can be characterized lithologically as sand, clay, or mixed sand/clay, and can be characterized hydrologically as exhibiting either high head or low head.

Geotechnical analysis indicates that Atterberg limits, index properties, consolidation state, and drainage conditions affect the shear strength of bluff materials. Silty …

Biodegradation Of Pah Contaminated Soil And Sludge Using Non-Ionic Surfactants, Seema Narula

Dissertations

Polycyclic aromatic hydrocarbons (PAHs) are one of the most prevalent environmental pollutants contaminating a large number of industrial and Superfund sites. Low solubility and sorption to solid surfaces limit biodegradation rates of PAHs in the environment. Bioremediation of these compounds have been previously tested with partial success. In the present study, aerobic biodegradation of three PAHs (fluorene, phenanthrene, and pyrene) has been studied in shaker flasks, batch fermenter, and bioslurry reactor, in the presence of non-ionic surfactants. A mixed bacterial culture derived from both a refinery sludge and an activated sludge was used as the seed population in the degradation …

Flag : The Fault-Line Analytic Graph And Fingerprint Classification, Ching-Yu Huang

Dissertations

Fingerprints can be classified into millions of groups by quantitative measurements of their new representations - Fault-Line Analytic Graphs (FLAG), which describe the relationship between ridge flows and singular points. This new model is highly mathematical, therefore, human interpretation can be reduced to a minimum and the time of identification can be significantly reduced.

There are some well known features on fingerprints such as singular points, cores and deltas, which are global features which characterize the fingerprint pattern class, and minutiae which are the local features which characterize an individual fingerprint image. Singular points are more important than minutiae when …

Effects Of Surfactants And Fenton's Reagents On Extraction And Destruction Of Phenanthrene In Spiked Sand, Ming-Chin Chang

Dissertations

In this study, surfactants and Fenton's reagents (Fe(II) and H₂0₂) ere proposed to solve contaminated site problems in situ on a lab scale. Phenanthrene is a simple PAHs (polynuclear aromatic hydrocarbons). The phenanthrene spiked ottawa sand simulated contaminated soil. HPLC was used for phenanthrene analysis because it provided excellent separation and no interference. Six surfactants (including nonionic and ionic) were tested. The operating conditions were optimized based on process and economic considerations such as reaction time, mixing speed, concentrations of surfactants and concentrations of Fenton's reagents. Surfactants could effectively dissolve phenanthrene from the spiked sand. In …

Mechanistic Studies Of Cation Photogeneration, Mary Frances Clifton

Dissertations

No abstract provided.

Biophysical Studies Of The Spectrin Sequence Motif, Denise M. Lusitani

Dissertations

No abstract provided.