Digital Commons Network^™

Affordances In The Design Of Virtual Environments, David Charles Gross

Electronic Theses and Dissertations

Human-computer interaction design principles largely focus on static representations and have yet to fully incorporate theories of perception appropriate for the dynamic multimodal interactions inherent to virtual environment (VE) interaction. Theories of direct perception, in particular affordance theory, may prove particularly relevant to enhancing VE interaction design. The present research constructs a conceptual model of how affordances are realized in the natural world and how lack of sensory stimuli may lead to realization failures in virtual environments. Implications of the model were empirically investigated by examining three affordances: passability, catchability, and flyability. The experimental design involved four factors for each …

Effect Of Source Water Blending On Copper Release In Pipe Distribution System: Thermodynamic And Empirical Models, Weizhong Xiao

Electronic Theses and Dissertations

This dissertation focuses on copper release in drinking water. Qualitative and quantitative assessment of Cu and Fe corrosion by process water quality was assessed over one year in a field study using finished waters produced from seven different treatment process and eighteen pilot distribution systems (PDSs) that were made from unlined cast iron and galvanized steel pipes, and lined cement and PVC pipes taken from actual distribution systems. Totally seven different waters were studied, which consisted of three source waters: groundwater, surface, and simulated brackish water designated as G1, S1, and RO. With certain pre-established blending ratios, these three waters …

Acoustic Waves In Lithium Niobate Plates, Ashwini Almad

Electronic Theses and Dissertations

No abstract provided.

Fast Algorithms For Fragment Based Completion In Images Of Natural Scenes, Siddharth Rajkumar Borikar

Electronic Theses and Dissertations

Textures are used widely in computer graphics to represent fine visual details and produce realistic looking images. Often it is necessary to remove some foreground object from the scene. Removal of the portion creates one or more holes in the texture image. These holes need to be filled to complete the image. Various methods like clone brush strokes and compositing processes are used to carry out this completion. User skill is required in such methods. Texture synthesis can also be used to complete regions where the texture is stationary or structured. Reconstructing methods can be used to fill in large-scale …

Teacher Performance Pay: The Perceptions Of Certified School-Based Pe, Gregory Adkins

Electronic Theses and Dissertations

To meet the continued demand for educational reform, the state of Florida enacted legislation in 1998 that required school boards to base a portion of the salary for school administrators and instructional personnel on performance. Although ahead of the required statutory timeline, the School District of Lee County implemented a teacher performance pay plan during the 1998–1999 school year as a result of Florida's legislative direction. The problem of this study was to determine the perceptions of Southwest Florida school-based certified staff regarding the implementation of teacher performance pay in a school district where performance pay had been in operation …

'A Man's World'?: A Study Of Female Workers At Nasa's Kennedy Space C, Nanci Schwartz

Electronic Theses and Dissertations

By focusing on women workers at NASA's Kennedy Space Center in Florida, this study seeks to understand why women were initially congregated in certain occupations such as clerical work and later moved into non-traditional jobs such as engineering and the sciences. Such an investigation requires careful examination of the changing attitudes towards female workers in technical or non-traditional fields and why and how those attitudes changed over time and the extent to which this occurred. It also attempts to identify areas of continuing concern. The study reveals that several factors contributed to the women's progress in the workplace. These included …

Monolithic Integration Of Dual Optical Elements On High Power Semicond, Laurent Vaissie

Electronic Theses and Dissertations

This dissertation investigates the monolithic integration of dual optical elements on high power semiconductor lasers for emission around 980nm wavelength. In the proposed configuration, light is coupled out of the AlGaAs/GaAs waveguide by a low reflectivity grating coupler towards the substrate where a second monolithic optical element is integrated to improve the device performance or functionality. A fabrication process based on electron beam lithography and plasma etching was developed to control the grating coupler duty cycle and shape. The near-field intensity profile outcoupled by the grating is modeled using a combination of finite-difference time domain (FDTD) analysis of the nonuniform …

Data Transmission Scheduling For Distributed Simulation Using Packet A, Juan Vargas-Morales

Electronic Theses and Dissertations

Communication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel time, queue length, and collision rate. Based on these results, Packet Alloying, a technique for the optimized bundling of packets, is proposed and evaluated. Packet Alloying becomes more active when it is …

Getting Involved : Motivational Programs And Strategies To Influence Adolescent Art Students' And Their Teachers' Involvement In Art Museums, Katherine Patten

Electronic Theses and Dissertations

No abstract provided.

Single User Data Throughput On The Forward Link Of A High Data Rate System, Ching-Sia Lim

Electronic Theses and Dissertations

No abstract provided.

A Comparison Of The Amount Of Whole Schools Training On Teachers' Attitudes Toward Arts Integration, Sherry Lynn Donaldson

Electronic Theses and Dissertations

No abstract provided.

The Production And Direction Of 'Proof' By David Auburn, Rebecca Bourgeois

Electronic Theses and Dissertations

No abstract provided.

Antenna Modeling By Infinitesimal Dipoles Using Genetic Algorithms / By Taninder S. Sijher, Taninder Sijher

Electronic Theses and Dissertations

No abstract provided.

A Software-Based Knowledge Management System Using Narrative Texts, Thomas Rudy Mcdaniel

Electronic Theses and Dissertations

Technical and professional communicators have in recent research been challenged to make significant contributions to the field of knowledge management, and to learn or create the new technologies allowing them to do so. The purpose of this dissertation is to make such a combined theoretical and applied contribution from the context of the emerging discipline of Texts and Technology. This dissertation explores the field of knowledge management (KM), particularly its relationship to the related study of artificial intelligence (AI), and then recommends a KM software application based on the principles of narratology and narrative information exchange. The focus of knowledge …

Development, Research And Validation Of Environmental Speciation Methods; And Evaluation By Speciated Isotope Dilution Mass Spectrometry In Mercury And Chromium Speciation Analysis, G. M. Mizanur Rahman

Electronic Theses and Dissertations

The toxicity of an element depends upon its chemical forms, which also gives vital information for samples and their relevance. A sequential extraction method for mercury speciation in soil and sediments was established based on the mobility and toxicity of different mercury species and was proposed as a draft US EPA Method 3200. In order to finalize the method, an interlaboratory validation study was performed, and the final results verified the applicability of the method. Some of the widely used mercury speciation methods were evaluated during this study and the results were compared with those obtained from EPA draft Method …

The Importance Of Cmos Sensor Surface Topography In The Attachment, Proliferation, And Differentiation Of Human Adult Mesenchymal Stem Cells, Christa Y. Heyward

Electronic Theses and Dissertations

Osteoblasts and osteoblast precursor cells (mesenchymal stem cells) respond to the surface topography of metal implants by aligning along surface features in order to minimize shear stress. While several previous studies have investigated the morphology, attachment and proliferation of both osteoblasts and mesenchymal stem cells along grooved surfaces, the current study investigates the cellular response to depressions and peaks in surface topography, as well as surfaces that contain alternating combinations of depressions and peaks. The Complementary Metal Oxide Semiconductor (CMOS) sensor is a transducer fabricated from silicon and sputter coated with titanium. The CMOS sensor is designed to utilize piezoresistive …

Analysis Of Factors That Influence Member Turnover In A Health Insurance Plan, Sara Bennett

Electronic Theses and Dissertations

In this research, we implement a multiple logistic regression model in which the coefficients of indicator variables are constrained to be zero or positive. By doing this, the contribution of each variable to the failure probability can be assessed. Due to this restriction on the coefficients, a Bayesian approach to parameter estimation--which assigns mixture priors to the coefficients--is taken. The data is provided by a large health insurance company in Western Pennsylvania and includes the enrollment status and corresponding values of the 84 predictor variables for 1,280,612 individuals. The insurer feels the analysis is needed to determine why its membership …

An Examination Of Standardized Language, Mathematics, And Reading Achievement Testing Results When Compared For Middle School Aged Student Leaders And Non-Student Leaders, Susan Schaming

Electronic Theses and Dissertations

The evolution of the middle school concept, according to Forte and Schurr (2003), with its own identity and its subsequent implementation, has proven to be an ideal or preferred model for educating students. Knowles and Brown (2000) assert the importance of middle level teachers' ability to nurture their students' academic, emotional, personal, and social development during the often "chaotic" years of transescence and early adolescence.

This study examined and explored sixty-four randomly selected seventh grade middle school students' earned scores on their annual standardized achievement testing, particularly the Terra Nova II Multiple Assessments subtests in the areas of Language, Mathematics, …

Teaching Science Through Inquiry In K-5 Classrooms: Analysis Of Change In Practice, Joseph Sciulli

Electronic Theses and Dissertations

The purpose of this study was to examine the role professional development takes in fostering change in the pedagogical practices of K-5 classroom teachers, specifically in teaching science through inquiry. Michael Fullan's three elements essential for change: curriculum, instruction, and philosophy, were used as the lens through which to observe and analyze the impact of an intervention for changing teaching practices in K-5 classrooms. The intervention that assisted in creating an environment for change in behaviors was a morphed version of the Exploratorium's Institute for Inquiry, the ASSET Institute for Inquiry, in Pittsburgh, Pennsylvania. During a three year period 208 …

Block Copolymer Stabilized Self-Assembled Magnetic Nanoparticles, Li Zhang

Electronic Theses and Dissertations

Magnetic materials are currently being developed in the areas of pharmacology and medicinal chemistry for use in applications such as drug delivery and magnetic resonance imaging. Magnetic fluids are being used in audio equipment and hard disk drives. Their suspension in a particular fluid is promoted by the adsorption or reaction of steric or electrostatic stabilizers, which are appropriate for the particular medium. Critical to the success of these magnetic fluids is the development of the steric stabilizers, which must prevent the coagulation of the metal particles. Polymeric materials are one of the most suitable nonmagnetic media to disperse the …

The Influence Of Students' Cognitive Style On A Standardized Reading Test Administered In Three Different Formats, Elizabeth Lynn Blanton

Electronic Theses and Dissertations

The purpose of this study was to examine the means of scores on three forms of a standardized reading comprehension test taken by community college students in developmental reading classes. The three forms of the test were administered as a timed multiple-choice test, a constructed response test, and an un-timed multiple-choice test. Scores on the Group Embedded Figures Test (GEFT) were used to classify the students who participated in the study as having field dependent (LOW GEFT), mid-field dependent/independent (MID GEFT), or fieldindependent (HIGH GEFT) tendencies. The paired samples test was used to analyze the scores among the students classified …

Multiple Scattering Of Light In Inhomogeneous Media And Applications, Claudia Mujat

Electronic Theses and Dissertations

Light scattering-based techniques are being developed for non-invasive diagnostics of inhomogeneous media in various fields, such as medicine, biology, and material characterization. However, as most media of interest are highly scattering and have a complex structure, it is difficult to obtain a full analytical solution of the scattering problem without introducing approximations and assumptions about the properties of the system under consideration. Moreover, most of the previous studies deal with idealized scattering situations, rarely encountered in practice. This dissertation provides new analytical, numerical, and experimental solutions to describe subtle effects introduced by the properties of the light sources, and by …

Optimal Upfc Control And Operations For Power Systems, Xiaohe Wu

Electronic Theses and Dissertations

The content of this dissertation consists of three parts. In the first part, optimal control strategies are developed for Unified Power Flow Controller (UPFC) following the clearance of fault conditions. UPFC is one of the most versatile Flexible AC Transmission devices (FACTs) that have been implemented thus far. The optimal control scheme is composed of two parts. The first is an optimal stabilization control, which is an open-loop ‘Bang’ type of control. The second is an suboptimal damping control, which consists of segments of ‘Bang’ type control with switching functions the same as those of a corresponding approximate linear system. …

The Design And Development Of A Comprehensive 49 Locus Y-Str Database For Major U.S. Populations, Paulina Niki Berdos

Electronic Theses and Dissertations

The establishment of a U.S. National Y-STR reference database from a variety of geographically and ethically diverse populations is essential to facilitate the generation of reliable estimates of Y-STR haplotype frequencies. Such multi-locus haplotype frequencies are required to provide a statistical estimate of the significance of a match. Y-STR loci, unlike traditional STR markers, are not independent of one another and are co-inherited as extended haplotypes of linked markers. The estimation of the frequency of occurrence of a particular haplotype therefore necessitates the use of a counting method, which means that the significance of many matches is dependent upon the …

Nascar Restrictor Plate Exhaust Manifold Design Strategies, Matthew John Dollhopf

Electronic Theses and Dissertations

This paper presents the results of a study on exhaust manifold design for a NASCAR Restrictor plate internal combustion engine. A computer simulation model was developed using Ricardo WAVE software. WAVE is a computer-aided engineering code developed by Ricardo to analyze the dynamics of pressure waves, mass flows and energy losses in ducts, plenums and the intake and exhaust manifolds of various systems and machines. [1] The model was validated against experimental data from a current NASCAR Winston Cup restrictor plate motor. The parameters studied have been exhaust manifold diameters and lengths. A response surface analysis of the simulation output …

Object Tracking And Activity Recognition In Video Acquired Using Mobile Cameras, Alper Yilmaz

Electronic Theses and Dissertations

Due to increasing demand on deployable surveillance systems in recent years, object tracking and activity recognition are receiving considerable attention in the research community. This thesis contributes to both the tracking and the activity recognition components of a surveillance system. In particular, for the tracking component, we propose two different approaches for tracking objects in video acquired by mobile cameras, each of which uses a different object shape representation. The first approach tracks the centroids of the objects in Forward Looking Infrared Imagery (FLIR) and is suitable for tracking objects that appear small in airborne video. The second approach tracks …

Design And Analysis Of Adaptive And Reconfigurable Antennas For Wireless Communication, Maha Abdelmoneim Mohamed Ali

Electronic Theses and Dissertations

Modern radar and communication systems have experienced a tremendous increase in the number of antennas onboard, on the ground, and in orbital space. This places a burden due to the confined volume and limited weight requirements especially in space applications. The reconfigurable antenna is a promising and exciting new type of antenna, where through the use of appropriate switches the antenna can be structurally reconfigured, to maintain the elements near their resonant dimensions for several frequency bands. This increases the bandwidth of the antenna dramatically, which enables the use of one antenna for several applications. Four novel reconfigurable antenna elements …

Application Of Absorptive Treatments On Traffic Noise Barriers In Florida, Chin Boon Chua

Electronic Theses and Dissertations

In this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier insertion loss. The best fit equation model was then used to test against measured/model result and TNM prediction results for its …

A Journey Of Teaching And Learning In Science Education: The Microculture Of Emerging Inquiry-Based Science Instruction In An Urban, Low Socioeconomic Elementary School Science Lab, Kimberly Dahl

Electronic Theses and Dissertations

This ethnographic study of emerging inquiry-based science instruction in an urban, low socioeconomic elementary school science lab was designed to gain insight into the perspectives of the teacher and students. The study involved a Central Florida elementary school whose population was over 80 percent African-American. In this six month study, the researcher examined the classroom setting of a science lab teacher and her fourth and fifth grade students during a six month period of time. Data sources included interviews, field notes, reflections, and student work , which were used to identify the emerging themes and patterns in the study. The …

Evolving Models From Observed Human Performance, Hans Karl Gustav Fernlund

Electronic Theses and Dissertations

To create a realistic environment, many simulations require simulated agents with human behavior patterns. Manually creating such agents with realistic behavior is often a tedious and time-consuming task. This dissertation describes a new approach that automatically builds human behavior models for simulated agents by observing human performance. The research described in this dissertation synergistically combines Context-Based Reasoning, a paradigm especially developed to model tactical human performance within simulated agents, with Genetic Programming, a machine learning algorithm to construct the behavior knowledge in accordance to the paradigm. This synergistic combination of well-documented AI methodologies has resulted in a new algorithm that …