Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2006

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 10411 - 10440 of 11371

Full-Text Articles in Entire DC Network

Undergraduate Catalog 2006-2007, University Of North Florida Jan 2006

Undergraduate Catalog 2006-2007, University Of North Florida

UNF Course Catalogs

No abstract provided.


Encouraging Knowledge Sharing In Knowledge-Based Organizations: Individual And Organizational Aspects Of Knowledge Management Leadership, Thomas Menkhoff, Yue Wah Chay, Benjamin Loh, Hans-Dieter Evers Jan 2006

Encouraging Knowledge Sharing In Knowledge-Based Organizations: Individual And Organizational Aspects Of Knowledge Management Leadership, Thomas Menkhoff, Yue Wah Chay, Benjamin Loh, Hans-Dieter Evers

Research Collection Lee Kong Chian School Of Business

This study aims to understand the antecedents of knowledge sharing behavior amongst tenant firms in Science and Technology Parks (STPs) which has been highlighted as a key factor for the development of an epistemic culture of innovation in STPs. Components of a model of knowledge management leadership with a focus on knowledge sharing and innovative value creation in STPs are developed inspired by the work of Nonaka, Nahapiet and Ghoshal, Guns and others. Collection of data on various relevant measures is ongoing, covering technology firms and STPs in Singapore and other Asian countries. Besides outlining model components and hypotheses, tentative …


Monolithic Integration Of Collimating Fresnel Lens For Beam Quality Enhancement In Tapered High Power Laser Diode, F. K. Lau, Chyng Wen Tee, X. Zhao, K. A. Williams, R. V. Penty, I. H. White, M. Calligaro, M. Lecomte, O. Parillaud, N. Michel, M. Krakowski Jan 2006

Monolithic Integration Of Collimating Fresnel Lens For Beam Quality Enhancement In Tapered High Power Laser Diode, F. K. Lau, Chyng Wen Tee, X. Zhao, K. A. Williams, R. V. Penty, I. H. White, M. Calligaro, M. Lecomte, O. Parillaud, N. Michel, M. Krakowski

Research Collection Lee Kong Chian School Of Business

We demonstrate, for the first time, a monolithic integrated lens for wide aperture gain-guided tapered laser beam quality enhancement by compensating the quadratic phase curvature. The 3mm long tapered laser with an output aperture of 170μm adopted in this design consists of a gain-guided tapered section and an index-guided ridge section and operated at 980nm. The lens design is implemented by focus ion beam etching (FIBE) technique, whereby the laser diode is mounted p-side up in order to facilitate the etching process. The lens is located 600μm away from the junction of the tapered and ridge sections, and is 40μm …


Constructing Indices Representing Supportiveness Of The Physical Environment For Walking Using The Rasch Measurement Model, Gavin R. Mccormack, Louise C. Mâsse, Max K. Bulsara, Terri J. Pikora, Billie Giles-Corti Jan 2006

Constructing Indices Representing Supportiveness Of The Physical Environment For Walking Using The Rasch Measurement Model, Gavin R. Mccormack, Louise C. Mâsse, Max K. Bulsara, Terri J. Pikora, Billie Giles-Corti

Medical Papers and Journal Articles

Background: The objectives of this study were to use the Rasch model to 1) assess the psychometric properties of a physical environmental audit instrument and 2) to develop indices of interrelated environmental attributes that summarize environmental supportiveness for walking.

Methods: A set of items were derived representing two conceptual physical environmental constructs: 1) functional/safety, and; 2) aesthetics. Ad hoc criteria based on point-biserial and Rasch-based fit statistics were used to examine the construct validity and internal reliability of the two constructs.

Results: The Rasch-based fit statistics assisted in identifying 12 items that belonged to the functional/safety construct and 4 items …


Moving A Part-Time Engineering Course To A Student-Centred Paradigm, Kevin Kelly Jan 2006

Moving A Part-Time Engineering Course To A Student-Centred Paradigm, Kevin Kelly

Level 3

This paper is a further reflection on two conference papers presented at the World Conference for Continuing Engineering Education (WCCEE) in Vienna in April 2006 and National University of Ireland (NUI) Galway Conference: The Challenge of Diversity: Teaching, Support and Student Learning , June 2006. Both conference papers dealt with different aspects of my experiences of the theoretical and pedagogical changes required in re-design and delivery of a part-time engineering programme for the continuing education development of electrical engineers in the workforce.


A Comparison Of Methods To Construct An Optimal Membership Function In A Fuzzy Database System, Joanne Marie Cunningham Jan 2006

A Comparison Of Methods To Construct An Optimal Membership Function In A Fuzzy Database System, Joanne Marie Cunningham

Theses and Dissertations

A fuzzy set is one in which membership in a category is not Boolean, rather items have a degree of membership. Fuzzy databases expand on this idea by storing fuzzy data and allowing data to be retrieved based on its degree of membership. Determining the degree of membership that satisfies the largest number of users is difficult. Five different methods of determining the membership function: the Direct Rating Method, the Random Method with step sizes of .02 and .03, the Steplock Method, and the Weighted Average Method, were compared on the basis of convergence and user satisfaction. The results support …


Optimal Clustering: Genetic Constrained K-Means And Linear Programming Algorithms, Jianmin Zhao Jan 2006

Optimal Clustering: Genetic Constrained K-Means And Linear Programming Algorithms, Jianmin Zhao

Theses and Dissertations

Methods for determining clusters of data under- specified constraints have recently gained popularity. Although general constraints may be used, we focus on clustering methods with the constraint of a minimal cluster size. In this dissertation, we propose two constrained k-means algorithms: Linear Programming Algorithm (LPA) and Genetic Constrained K-means Algorithm (GCKA). Linear Programming Algorithm modifies the k-means algorithm into a linear programming problem with constraints requiring that each cluster have m or more subjects. In order to achieve an acceptable clustering solution, we run the algorithm with a large number of random sets of initial seeds, and choose the solution …


Enhancing The Third-Order Nonlinear Optical Properties Of Porphyrins And Molecular Wires, Jonathan L. Humphrey Jan 2006

Enhancing The Third-Order Nonlinear Optical Properties Of Porphyrins And Molecular Wires, Jonathan L. Humphrey

Theses and Dissertations

The third-order nonlinear optical (NLO) properties of indium tin oxide (ITO) thin films, Fe3+, Mn3+, Co2+ 5,10,15,20-tetrakis-4hydroxytetraphenyl)porphyrin (TPP) films, and a series of ethynyl-linked azobenzene oligomers were investigated using degenerate four wave mixing (DFWM) with 100 fs laser pulses. To measure the NLO of ITO thin films, A DFWM method for measuring thin films on thick substrates was refined for the characterization of films less than 100 nm thick and applied to ITO films ~25 nm thick. It was found that the third-order nonlinear susceptibility of ITO, χ(3)ITO, is purely electronic at 900 - 1300 nm (11000 - 7700 cm-1) …


Spin Polarized Transport In Nanoscale Devices, Sandipan Pramanik Jan 2006

Spin Polarized Transport In Nanoscale Devices, Sandipan Pramanik

Theses and Dissertations

The ultimate goal in the rapidly burgeoning field of spintronics is to realize semiconductor-based devices that utilize the spin degree of freedom of a single charge carrier (electron or hole) or an ensemble of such carriers to achieve novel and/or enhanced device functionalities such as spin based light emitting devices, spin transistors and femto-Tesla magnetic field sensors. These devices share a common feature: they all rely on controlled transport of spins in semiconductors. A prototypical spintronic device has a transistor-like configuration in which a semiconducting channel is sandwiched between two contacts (source and drain) with a gate electrode sitting on …


A Comparison For Longitudinal Data Missing Due To Truncation, Rong Liu Jan 2006

A Comparison For Longitudinal Data Missing Due To Truncation, Rong Liu

Theses and Dissertations

Many longitudinal clinical studies suffer from patient dropout. Often the dropout is nonignorable and the missing mechanism needs to be incorporated in the analysis. The methods handling missing data make various assumptions about the missing mechanism, and their utility in practice depends on whether these assumptions apply in a specific application. Ramakrishnan and Wang (2005) proposed a method (MDT) to handle nonignorable missing data, where missing is due to the observations exceeding an unobserved threshold. Assuming that the observations arise from a truncated normal distribution, they suggested an EM algorithm to simplify the estimation.In this dissertation the EM algorithm is …


Public: An Exploration Of Community, Environment, And Technology, Christopher John Malven Jan 2006

Public: An Exploration Of Community, Environment, And Technology, Christopher John Malven

Theses and Dissertations

This project examines the potential of computer technology to enhance navigation within, and incorporate information-sharing into, the public urban environment.


A Study Of The Relationship Between School Climate And Student Performance On The Virginia Standards Of Learning Tests In Elementary Schools, Victoria Lee Thomasson Jan 2006

A Study Of The Relationship Between School Climate And Student Performance On The Virginia Standards Of Learning Tests In Elementary Schools, Victoria Lee Thomasson

Theses and Dissertations

Educators are examining many aspects of schools as they find ways to help students improve their performance on standardized tests in order to meet both federal and state standards. This study examined the relationship between organizational climate and student achievement on the Virginia Standards of Learning tests. A total of 1,061 teachers in 47 schools across the Commonwealth of Virginia responded to the climate survey. The survey instrument was the Organizational Health Inventory for Elementary Schools (OHI-E). This brief survey instrument examined five aspects of school climate. They were Teacher Affiliation, Collegial Leadership, Resource Influence, Institutional Integrity, and Academic Emphasis. …


Drawing Through A Linear Temperament, Jorge Miguel Benitez Jan 2006

Drawing Through A Linear Temperament, Jorge Miguel Benitez

Theses and Dissertations

I am a draftsman, painter and printmaker. This first person statement is a written extension of the art that constitutes my thesis. It discusses the links between my work and the Enlightenment, Humanism, Catholicism, ethics and the Western canon as well as my use of perspective and other classical techniques in relation to history, language, high art, popular culture, propaganda, contemporary upheavals, Christian and Islamic Fundamentalism, globalization and the digital revolution. Furthermore, the main arguments draw upon my Cuban origin and European ancestry, the Cuban Revolution, my Belgian early education and eventual American hybrid identity. The overriding theme, however, concerns …


K X N Trust-Based Agent Reputation, Christopher Alonzo Parker Jan 2006

K X N Trust-Based Agent Reputation, Christopher Alonzo Parker

Theses and Dissertations

In this research, a multi-agent system called KMAS is presented that models an environment of intelligent, autonomous, rational, and adaptive agents that reason about trust, and adapt trust based on experience. Agents reason and adapt using a modification of the k-Nearest Neighbor algorithm called (k X n) Nearest Neighbor where k neighbors recommend reputation values for trust during each of n interactions. Reputation allows a single agent to receive recommendations about the trustworthiness of others. One goal is to present a recommendation model of trust that outperforms MAS architectures relying solely on direct agent interaction. A second goal is to …


Relationships Among Stress, Blood Pressure, And Heart Rate Variability In Meditators, Sangthong Terathongkum Jan 2006

Relationships Among Stress, Blood Pressure, And Heart Rate Variability In Meditators, Sangthong Terathongkum

Theses and Dissertations

PROBLEM STATEMENT: Growing evidence indicates that psychological stress contributes to cardiovascular diseases through complex neuroendocrine mechanisms. Psychological stress leads to several physiological responses including increased heart rate (HR) and blood pressure (BP) as well as decreased heart rate variability (HRV) through alterations in the autonomic nervous system (ANS), specifically increased sympathetic nervous system (SNS) activity and decreased parasympathetic nervous system (PNS) activity. Meditation is thought to induce an innate relaxation response leading to reduced psychological stress. Findings from past studies have provided inconclusive evidence regarding the direction and strength of relationships among stress, BP, HRV, and meditation practice. PROCEDURES: A …


Chemometric Analysis Of Multivariate Liquid Chromatography Data: Applications In Pharmacokinetics, Metabolomics, And Toxicology, Sarah Elizabeth Graham Porter Jan 2006

Chemometric Analysis Of Multivariate Liquid Chromatography Data: Applications In Pharmacokinetics, Metabolomics, And Toxicology, Sarah Elizabeth Graham Porter

Theses and Dissertations

In the first part of this work, LC-MS data were used to calculate the in-vitro intrinsic clearances (CLint) for the metabolism of p-methoxyrnethamphetamine (PMMA) and fluoxetine by the CYP2D6 enzyme using a steady-state (SS) approach and a new general enzyme (GE) screening method. For PMMA, the SS experiment resulted in a CLint of 2.7 ± 0.2 µL pmol 2D6-1min-1 and the GE experiment resulted in a CLint of 3.0 ± 0.6 µL pmol 2D6-1min-1. For fluoxetine, the SS experiment resulted in a CLint of 0.33 ± 0.17 µL pmol 2D6-1min-1 and the GE experiment resulted in a CLint of 0.188 …


A Model To Predict 24-Hour Urinary Creatinine Level Using Repeated Measurements, Donna S. Kroos Jan 2006

A Model To Predict 24-Hour Urinary Creatinine Level Using Repeated Measurements, Donna S. Kroos

Theses and Dissertations

Creatinine is a metabolic waste product, removed from the blood by the kidneys, and excreted in the urine. The measurement of creatinine is used in the assessment and monitoring of many medical conditions as well as in the determination or adjustment of absorbed dosage of pesticides. Earlier models to predict 24-hour urinary creatinine used ordinary least squares regression and assumed that the subjects' observations were uncorrelated. However, many of these studies had repeated creatinine measurements for each of their subjects. Repeated measures on the same subject frequently are correlated. Using data from the NIOSH-CDC "Pesticide Dose Monitoring in Turf Applicators" …


Forecasting Stability Levels For The Countries Of The Former Soviet Union, Margaret Erin Keck Jan 2006

Forecasting Stability Levels For The Countries Of The Former Soviet Union, Margaret Erin Keck

Theses and Dissertations

United States intelligence officers and policymakers need reliable forecasts of country, regional, and global stability or instability. Such forecasts require a methodology for identifying and analyzing factors that contribute to stability. The anticipation of this stability level can facilitate crisis warning and diplomatic strategies for various timelines, including five, ten, and twenty year forecasts. While the problem of forecasting can be tackled in various ways, in the interest of time and space, I will only go into a few of them. The approach I will use is multiple linear regression to generate a short-term forecast for the stability levels of …


The Oldest Well, Saul Benjamin Becker Jan 2006

The Oldest Well, Saul Benjamin Becker

Theses and Dissertations

This body of work, representing the past two years, is focused on the idea of the composite landscape. This reconfiguring of the elements from the external world combined with invented places is a way for me to articulate the subtle transactions between the interior psyche and the external world. The way this new conglomerate space is represented is a result of my inquiry into the relationship between nature, culture, and the sublime. The place where the private acts of the studio meet the shared exterior world is where I find my intellect, fantasy, and sense of reality collaborating in chorus.


Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne Jan 2006

Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne

Theses and Dissertations

The processes leading to the widespread presence of crystalline silicates throughout the galaxy and the origin of silicon nanoparticles thought to be responsible for the observed extended red emission in diffuse galactic background are still far from being understood. One of the most abundant oxygen bearing species in molecular astronomical regions is SiO. It has been conjectured that silicate formation probably proceeds via the agglomeration of these molecular species; however there are no studies to reveal the microscopic mechanism. We have used a synergistic approach combining experiments in molecular beams and first principles theoretical calculation to demonstrate that the passage …


Grobner Bases And Ideals Of Points, Eun R. Chang Jan 2006

Grobner Bases And Ideals Of Points, Eun R. Chang

Theses and Dissertations

The main point of this thesis is an introduction to the theory of Grobner bases. The concept of Grobner basis and construction of the Grobner basis by Buchberger's Algorithm, in which the notion of S-polynomials is introduced, and a few modified or improved versions of Grobner basis algorithm are reviewed in this paper. In Chapter 1, we have a review of ideals, the definitions and types of monomial ordering, the multivariate polynomial division algorithm and its examples. After ascertaining the monomial ordering on multivariate polynomials, we establish a leading term of a polynomial.In Chapter 2, after defining Grobner bases, we …


A Longitudinal Investigation Of Cognitive Predictors Of Self-Care Behaviors In Youth With Type I Diabetes, Michelle Marie Greene Jan 2006

A Longitudinal Investigation Of Cognitive Predictors Of Self-Care Behaviors In Youth With Type I Diabetes, Michelle Marie Greene

Theses and Dissertations

Cross-sectional research of youth with type I diabetes has demonstrated that rote and working memory predict blood glucose monitoring (BGM) and carbohydrate consumption, respectively; however, to date, no longitudinal follow-up studies exist. Rote and working memory subtests from well-standardized memory measures, along with a problem-solving and executive functioning measures were administered to 118 youth with type I diabetes, aged 9-16 in two waves of data collection (mean interval = 2.07 years). Diabetes care behaviors were assessed through the 24-hour Diabetes Interview. This study was the first to document longitudinal prediction of BGM by rote memory and fat consumption by working …


A Gis And Remote Sensing Based Analysis Of Impervious Surface Influences On Bald Eagle (Haliaeetus Leucocephalus) Nest Presence In The Virginia Portion Of The Chesapeake Bay, Jennifer M. Ciminelli Jan 2006

A Gis And Remote Sensing Based Analysis Of Impervious Surface Influences On Bald Eagle (Haliaeetus Leucocephalus) Nest Presence In The Virginia Portion Of The Chesapeake Bay, Jennifer M. Ciminelli

Theses and Dissertations

GIS (Geographic Information Systems) and remote sensing techniques were used to predict relationships between bald eagle nest presences and land type, distance to land type and impervious surface cover area. Data plots revealed bald eagle nest presence decreases in response to an increase in area of bareland; increases with an increase in area of forested land; decreases with an increase in distance (m) to shoreline, and decreases in response to an increase in area of impervious surfaces. Logistic regression models identified impervious surfaces as an indicator for bald eagle nest presence (P 24% as unsuitable. Unsuitable area covered 17.82% of …


Photochemical Applications To The Study Of Complexity Phospholipid Bilayer Environments, Christopher John Wohl Jr. Jan 2006

Photochemical Applications To The Study Of Complexity Phospholipid Bilayer Environments, Christopher John Wohl Jr.

Theses and Dissertations

The physical and biophysical properties of a biological membrane model, phosphatidylcholine bilayers, were investigated using novel spiropyran/merocyanine molecular probes. The femtosecond to second dynamics of this system's photochemistry enabled bilayer viscosity and free volume to be studied over a broad time scale. Spiropyrans/merocyanines with different polarity were synthesized by changing the substitution of the indole moiety enabling determination of the trans-membrane properties of the bilayer. In addition, transient grating spectroscopy was used to study thermal energy transfer in phospholipid bilayers on a picosecond time scale.Femtosecond transient absorption spectroscopy was used to study the photo-induced spiropyran ring-opening and isomerization reactions that …


Statistical Methods And Experimental Design For Inference Regarding Dose And/Or Interaction Thresholds Along A Fixed-Ratio Ray, Sharon Dziuba Yeatts Jan 2006

Statistical Methods And Experimental Design For Inference Regarding Dose And/Or Interaction Thresholds Along A Fixed-Ratio Ray, Sharon Dziuba Yeatts

Theses and Dissertations

An alternative to the full factorial design, the ray design is appropriate for investigating a mixture of c chemicals, which are present according to a fixed mixing ratio, called the mixture ray. Using single chemical and mixture ray data, we can investigate interaction among the chemicals in a particular mixture. Statistical models have been used to describe the dose-response relationship of the single agents and the mixture; additivity is tested through the significance of model parameters associated with the coincidence of the additivity and mixture models.It is often assumed that a chemical or mixture must be administered above an unknown …


A Normal-Mixture Model With Random-Effects For Rr-Interval Data, Jessica Mckinney Ketchum Jan 2006

A Normal-Mixture Model With Random-Effects For Rr-Interval Data, Jessica Mckinney Ketchum

Theses and Dissertations

In many applications of random-effects models to longitudinal data, such as heart rate variability (HRV) data, a normal-mixture distribution seems to be more appropriate than the normal distribution assumption. While the random-effects methodology is well developed for several distributions in the exponential family, the case of the normal-mixture has not been dealt with adequately in the literature. The models and the estimation methods that have been proposed in the past assume the conditional model (fixing the random-effects) to be normal and allow a mixture distribution for the random effects (Xu and Hedeker, 2001, Xu, 1995). The methods proposed in this …


A Prelude To A Third Dimension Of The Periodic Table: Superatoms Of Aluminum Iodide Clusters, Naiche Owen Jones Jan 2006

A Prelude To A Third Dimension Of The Periodic Table: Superatoms Of Aluminum Iodide Clusters, Naiche Owen Jones

Theses and Dissertations

Calculations have been carried out to investigate the stability and electronic structure of aluminum iodide clusters using first principles gradient-corrected density functional theory. Analysis of A113Ix-, A114Ix-, and A17I- clusters reveals that their stability is governed by the geometrically unperturbed A113-, A1142+, and A17+ units, respectively, that are demonstrated to constitute the compact cores of the clusters upon significant iodine content. The compact, icosahedral A113, icosahedral-like A1 14, and capped square bi-pyramid A17 superatom structures of the stable aluminum cores have an analogous electronic configuration to that of halogen, alkaline-earth, and alkaline atoms, respectively. Novel chemistry is demonstrated in superatoms, …


Synthesis Of Novel Antimycobacterials And A Fluorescent Sensor For Simple Carbohydrates, Brian Thomas Walker Jan 2006

Synthesis Of Novel Antimycobacterials And A Fluorescent Sensor For Simple Carbohydrates, Brian Thomas Walker

Theses and Dissertations

Cell surface carbohydrates play an important role in a wide variety of biological processes such as inflammation, tumor metastasis, and viral and bacterial infection. The goal of our research has been two-fold. The first objective was the synthesis of antimycobacterial compounds. A mannose containing tetrasaccharide from the mannan core of lipoarabinomannan (LAM) of Mycobacterium tuberculosis has been synthesized using α-D-methylmannopyranoside as starting material and Koeings-Knorr reactions to couple saccharides. The synthesis was completed in nine steps and in 14% total yield. This compound should be useful in competitive inhibition studies with macrophages or as an immunological marker. We have successfully …


Journaling For Critical Thinking, Paul E. Terrell Jr. Jan 2006

Journaling For Critical Thinking, Paul E. Terrell Jr.

Theses and Dissertations

This thesis describes a pretest - posttest study to increase the effectiveness of art journals at the high school level. The targeted population consisted of students in the ninth through twelfth grades in a middle class community, located in central Virginia. The visual art students were involved in the journaling (art workbook, sketchbook) process as a part of their curriculum. Following a pretest students were surveyed and adjustments were made from their input to make the art journals more effective. Often students were not picking up instructional cues introduced through demonstrations and art history integrated into the class structure. The …


Membership Functions For A Fuzzy Relational Database: A Comparison Of The Direct Rating And New Random Proportional Methods, Shweta Sanghi Jan 2006

Membership Functions For A Fuzzy Relational Database: A Comparison Of The Direct Rating And New Random Proportional Methods, Shweta Sanghi

Theses and Dissertations

Fuzzy relational databases deal with imprecise data or fuzzy information in a relational database. The purpose of this fuzzy database implementation is to retrieve images by using fuzzy queries whose common-language descriptions are defined by the consensus of a particular user community. The fuzzy set, which is presentation of fuzzy attribute values of the images, is determined through membership function. This paper compares two methods of constructing membership functions, the Direct Rating and New Random Proportional, to determine which method gives maximum users satisfaction with minimum feedback from the community. The statistical analysis of results suggests the use of Direct …