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2004

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Articles 3781 - 3810 of 3869

Full-Text Articles in Physical Sciences and Mathematics

Interactivity And User-Heterogeneity In On Demand Broadcast Video, Mounir Tantaoui El Araki Jan 2004

Interactivity And User-Heterogeneity In On Demand Broadcast Video, Mounir Tantaoui El Araki

Electronic Theses and Dissertations

Video-On-Demand (VOD) has appeared as an important technology for many multimedia applications such as news on demand, digital libraries, home entertainment, and distance learning. In its simplest form, delivery of a video stream requires a dedicated channel for each video session. This scheme is very expensive and non-scalable. To preserve server bandwidth, many users can share a channel using multicast. Two types of multicast have been considered. In a non-periodic multicast setting, users make video requests to the server; and it serves them according to some scheduling policy. In a periodic broadcast environment, the server does not wait for service …


Mitochondrial Dna Analysis By Pyrosequencing, Patsy-Ann Susan Hastings Jan 2004

Mitochondrial Dna Analysis By Pyrosequencing, Patsy-Ann Susan Hastings

Electronic Theses and Dissertations

Mitochondrial DNA (deoxyribo nucleic acid) is typically used in forensic casework when small quantities of high molecular weight quality DNA is not expected to be present thus negating the chances of obtaining usable nuclear DNA. Typical samples that utilized mitochondrial DNA analysis are: hair, bones, teeth, ancient remains (samples or remains that are at least 100 years old) or very old samples (samples that are less than 100 but greater than 10 years old). The current method used to evaluate mitochondrial DNA is Sanger sequencing. Although robust, it is also time consuming and labor intensive, on the other hand pyrosequencing …


Smoothing Parameter Selection In Nonparametric Functional Estimation, Mohamed Amezziane Jan 2004

Smoothing Parameter Selection In Nonparametric Functional Estimation, Mohamed Amezziane

Electronic Theses and Dissertations

This study intends to build up new techniques for how to obtain completely data-driven choices of the smoothing parameter in functional estimation, within the confines of minimal assumptions. The focus of the study will be within the framework of the estimation of the distribution function, the density function and their multivariable extensions along with some of their functionals such as the location and the integrated squared derivatives.


Individual Carbon Nanotube Probes And Field Emitters Fabrication And T, Guangyu Chai Jan 2004

Individual Carbon Nanotube Probes And Field Emitters Fabrication And T, Guangyu Chai

Electronic Theses and Dissertations

Since the discovery of carbon nanotubes (CNT) in 1999, they have attracted much attention due to their unique mechanical and electrical properties and potential applications. Yet their nanosize makes the study of individual CNTs easier said than done. In our laboratory, carbon fibers with nanotube cores have been synthesized with conventional chemical vapor deposition (CVD) method. The single multiwall carbon nanotube (MWNT) sticks out as a tip of the carbon fiber. In order to pick up the individual CNT tips, focused ion beam (FIB) technique is applied to cut and adhere the samples. The carbon fiber with nanotube tip was …


Measures Of Concordance Of Polynomial Type, Heather Edwards Jan 2004

Measures Of Concordance Of Polynomial Type, Heather Edwards

Electronic Theses and Dissertations

A measure of concordance, $\kappa$, is of polynomial type if and only if $\kappa (tA+(1-t)B)$ is a polynomial in $t$ where $A$ and $B$ are 2-copulas. The degree of such a type of measure of concordance is simply the highest degree of the polynomial associated with $\kappa$. In previous work [2], [3], properties of measures of concordance preserving convex sums (equivalently measures of concordance of polynomial type degree one) were established; however, a characterization was not made. Here a characterization is made using approximations involving doubly stochastic matrices. Other representations are provided from this characterization leading naturally to two interpretations …


Asymptotic Formulas For Large Arguments Of Hypergeometric-Type Functio, Adam Heck Jan 2004

Asymptotic Formulas For Large Arguments Of Hypergeometric-Type Functio, Adam Heck

Electronic Theses and Dissertations

Hypergeometric type functions have a long list of applications in the field of sciences. A brief history is given of Hypergeometric functions including some of their applications. A development of a new method for finding asymptotic formulas for large arguments is given. This new method is applied to Bessel functions. Results are compared with previously known methods.


Automatic Annotation Of Database Images For Query-By-Concept, Nualsawat Hiransakolwong Jan 2004

Automatic Annotation Of Database Images For Query-By-Concept, Nualsawat Hiransakolwong

Electronic Theses and Dissertations

As digital images become ubiquitous in many applications, the need for efficient and effective retrieval techniques is more demanding than ever. Query by Example (QBE) and Query by Concept (QBC) are among the most popular query models. The former model accepts example images as queries and searches for similar ones based on low-level features such as colors and textures. The latter model allows queries to be expressed in the form of high-level semantics or concept words, such as "boat" or "car," and finds images that match the specified concepts. Recent research has focused on the connections between these two models …


Toward Building A Social Robot With An Emotion-Based Internal Control, Andreas Marpaung Jan 2004

Toward Building A Social Robot With An Emotion-Based Internal Control, Andreas Marpaung

Electronic Theses and Dissertations

In this thesis, we aim at modeling some aspects of the functional role of emotions on an autonomous embodied agent. We begin by describing our robotic prototype, Cherry--a robot with the task of being a tour guide and an office assistant for the Computer Science Department at the University of Central Florida. Cherry did not have a formal emotion representation of internal states, but did have the ability to express emotions through her multimodal interface. The thesis presents the results of a survey we performed via our social informatics approach where we found that: (1) the idea of having emotions …


Image Based View Synthesis, Jiangjian Xiao Jan 2004

Image Based View Synthesis, Jiangjian Xiao

Electronic Theses and Dissertations

This dissertation deals with the image-based approach to synthesize a virtual scene using sparse images or a video sequence without the use of 3D models. In our scenario, a real dynamic or static scene is captured by a set of un-calibrated images from different viewpoints. After automatically recovering the geometric transformations between these images, a series of photo-realistic virtual views can be rendered and a virtual environment covered by these several static cameras can be synthesized. This image-based approach has applications in object recognition, object transfer, video synthesis and video compression. In this dissertation, I have contributed to several sub-problems …


Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat Jan 2004

Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat

Electronic Theses and Dissertations

Polarimetry is one of the principal means of investigating the interaction of light with matter. Theoretical models and experimental techniques are presented in this dissertation for polarimetric characterization of random electromagnetic beams and of signatures of random media in different scattering regimes and configurations. The degree of polarization rather than the full description of the state of polarization is of interest in multiple scattering and free space propagation where the statistical nature and not the deterministic component of light bears the relevant information. A new interferometric technique for determining the degree of polarization by measuring the intensity fluctuations in a …


Quadratic Spatial Soliton Interactions, Ladislav Jankovic Jan 2004

Quadratic Spatial Soliton Interactions, Ladislav Jankovic

Electronic Theses and Dissertations

Quadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO3) and periodically poled potassium titanyl phosphate (KTP) crystals. These particular crystals were desirable for these experiments because of their large nonlinear coefficients and, more importantly, because the experiments could be performed under non-critical-phase-matching (NCPM) conditions. The single soliton generation measurements, performed on KNBO3 by launching the …


Stability And Recovery Of Rna In Biological Stains, Mindy Eileen Setzer Jan 2004

Stability And Recovery Of Rna In Biological Stains, Mindy Eileen Setzer

Electronic Theses and Dissertations

In theory, RNA expression patterns, including the presence and relative abundance of particular RNA species, provide cell and tissue specific information that could be of use to forensic scientists. An mRNA based approach could allow the facile identification of the tissue components present in a body fluid stain and conceivably could supplant the battery of serological and biochemical tests currently employed in the forensic serology laboratory. Some of the potential advantages include greater test specificity, and the ability to perform simultaneous analysis using a common assay format for the presence of all body fluids of forensic interest. In this report, …


Stable Spatial Solitons In Semiconductor Optical Amplifiers, Erdem Ultanir Jan 2004

Stable Spatial Solitons In Semiconductor Optical Amplifiers, Erdem Ultanir

Electronic Theses and Dissertations

A spatial soliton is a shape invariant self guided beam of light or a self induced waveguide. Spatial solitons appear as a result of the balance of diffraction and nonlinear focusing in a system. They have been observed in many different conservative media in the last couple of years. Solitons are ubiquitous, because of the probability of using their interactions in optical data processing, communications etc. Up to now due to the power required to generate the solitons, and the response times of the soliton supporting media, these special waves of nature could not penetrate the applications arena. Semiconductors, with …


Dispersion-Managed Breathing-Mode Semiconductor Mode-Locked Ring Laser, Bojan Resan Jan 2004

Dispersion-Managed Breathing-Mode Semiconductor Mode-Locked Ring Laser, Bojan Resan

Electronic Theses and Dissertations

A novel dispersion-managed breathing-mode semiconductor mode-locked ring laser is developed. The "breathing-mode" designation derives from the fact that intracavity pulses are alternately stretched and compressed as they circulate around the ring resonator. The pulses are stretched before entering the semiconductor gain medium to minimize the detrimental strong integrating self-phase modulation and to enable efficient pulse amplification. Subsequently compressed pulses facilitate bleaching the semiconductor saturable absorber. The intracavity pulse compression ratio is higher than 50. Down chirping when compared to up chirping allows broader mode-locked spectra and shorter pulse generation owing to temporal and spectral semiconductor gain dynamics. Pulses as short …


Towards Direct Writing Of 3-D Photonic Circuits Using Ultrafast Lasers, Arnaud Zoubir Jan 2004

Towards Direct Writing Of 3-D Photonic Circuits Using Ultrafast Lasers, Arnaud Zoubir

Electronic Theses and Dissertations

The advent of ultrafast lasers has enabled micromachining schemes that cannot be achieved by other current techniques. Laser direct writing has emerged as one of the possible routes for fabrication of optical waveguides in transparent materials. In this thesis, the advantages and limitations of this technique are explored. Two extended-cavity ultrafast lasers were built and characterized as the laser sources for this study, with improved performance over existing systems. Waveguides are fabricated in oxide glass, chalcogenide glass, and polymers, these being the three major classes of materials for the telecommunication industry. Standard waveguide metrology is performed on the fabricated waveguides, …


Designing And Implementing A User-Focused Web-Based Database System, Rachel Noiseux Jan 2004

Designing And Implementing A User-Focused Web-Based Database System, Rachel Noiseux

Honors Theses

The goal of this project was to combine two different fields within computer science to produce a system that would be beneficial to a wide variety of people. The first area, user-centered design, studies how users interact with an interface and the motivation behind the decisions they make when interacting with the interface. The second area, databases, explores different techniques for storing and retrieving large amounts of data.


New Methods For Exafs Analysis In Structural Genomics, Grant Bunker, Nicholas Dimakis, Gocha Kelashvili Jan 2004

New Methods For Exafs Analysis In Structural Genomics, Grant Bunker, Nicholas Dimakis, Gocha Kelashvili

Physics & Astronomy Faculty Publications

Data analysis is one of the remaining bottlenecks in high-throughput EXAFS for structural genomics. Here some recent developments in methodology are described that offer the potential for rapid and automated XAS analysis of metalloproteins.


Probing Molecular Free Energy Landscapes By Periodic Loading, Oliver Braun, Andreas Hanke, Udo Seifert Jan 2004

Probing Molecular Free Energy Landscapes By Periodic Loading, Oliver Braun, Andreas Hanke, Udo Seifert

Physics & Astronomy Faculty Publications

Single molecule pulling experiments provide information about interactions in biomolecules that cannot be obtained by any other method. However, the reconstruction of the molecule’s free energy profile from the experimental data is still a challenge, in particular, for the unstable barrier regions. We propose a new method for obtaining the full profile by introducing a periodic ramp and using Jarzynski’s relation for obtaining equilibrium quantities from nonequilibrium data. Our simulated experiments show that this method delivers significant more accurate data than previous methods, under the constraint of equal experimental effort.


Generation Of The Transient Electrical And Spontaneous Magnetic Fields By Solid State Combustion, Karen S. Martirosyan, J. R. Claycomb, J. H. Miller Jr., D. Luss Jan 2004

Generation Of The Transient Electrical And Spontaneous Magnetic Fields By Solid State Combustion, Karen S. Martirosyan, J. R. Claycomb, J. H. Miller Jr., D. Luss

Physics & Astronomy Faculty Publications

Experiments revealed that transient electric field intensities up to 2.5 V/cm were generated during the initial period of combustion synthesis of the ferromagnetic products before the maximum temperature was reached. This occurred when the iron particles were partially oxidized and the reaction product was mainly magnetite sFe3O4d. The electromagnetic field caused spontaneous magnetization of the product in the postcombustion zone. Magnetic field values up to 4 µT formed after the sample temperature fell below the Curie temperature and the initial reactants were completely converted to the ferromagnetic phase PbFe12O19. Increasing the volume of the samples increases the absolute residual magnetic …


Recent Trends In Software Engineering Research As Seen Through Its Publications, Terry L. Smith Jan 2004

Recent Trends In Software Engineering Research As Seen Through Its Publications, Terry L. Smith

UNF Graduate Theses and Dissertations

This study provides some insight into the field of software engineering through analysis of its recent research publications. Data for this study are taken from the ACM's Guide to Computing Literature (GUIDE) They include both the professionally assigned Computing Classification System (CCS) descriptors and the title text of each software engineering publication reviewed by the GUIDE from 1998 through 2001.

The first part of this study provides a snapshot of software engineering by applying co-word analysis techniques to the data. This snapshot indicates recent themes or areas of interest, which, when compared with the results from earlier studies, reveal current …


Preconceived Physician Attitude Toward Computerized Physician Order Entry (Cpoe): Implications For Successful Implementation, John Arthur Hoffstatter Jan 2004

Preconceived Physician Attitude Toward Computerized Physician Order Entry (Cpoe): Implications For Successful Implementation, John Arthur Hoffstatter

UNF Graduate Theses and Dissertations

There has been a societal and legislative push to implement computerized physician order entry (CPOE) systems throughout hospitals nationally in recent years due in large part to the public's awareness of an inordinate number of patient deaths due to medication errors in hospital settings. This mortality, and untold morbidity, became even more unacceptable when published findings suggested the majority of these 100,000 deaths each year could be avoided through the use of CPOE systems.

Yet acceptance has been slow and only a fraction of the hospitals have implemented this technology due to large start up costs, enormous technological requirements, and …


Pupil Phase Apodization For Achromatic Imaging Of Extra-Solar Planets, Weidong Yang Jan 2004

Pupil Phase Apodization For Achromatic Imaging Of Extra-Solar Planets, Weidong Yang

Dissertations, Master's Theses and Master's Reports - Open

Direct imaging of extra-solar planets in the visible and infrared region has generated great interest among scientists and the general public as well. However, this is a challenging problem. Diffculties of detecting a planet (faint source) are caused, mostly, by two factors: sidelobes caused by starlight diffraction from the edge of the pupil and the randomly scattered starlight caused by the phase errors from the imperfections in the optical system. While the latter diffculty can be corrected by high density active deformable mirrors with advanced phase sensing and control technology, the optimized strategy for suppressing the diffraction sidelobes is still …


Application Of Well Log Tomography To The Dundee And Rogers City Limestones, Michigan Basin, Usa, Mellisa A. Le M. Jan 2004

Application Of Well Log Tomography To The Dundee And Rogers City Limestones, Michigan Basin, Usa, Mellisa A. Le M.

Dissertations, Master's Theses and Master's Reports - Open

The Michigan Basin is located in the upper Midwest region of the United States and is centered geographically over the Lower Peninsula of Michigan. It is filled primarily with Paleozoic carbonates and clastics, overlying Precambrian basement rocks and covered by Pleistocene glacial drift. In Michigan, more than 46,000 wells have been drilled in the basin, many producing significant quantities of oil and gas since the 1920s in addition to providing a wealth of data for subsurface visualization.

Well log tomography, formerly log-curve amplitude slicing, is a visualization method recently developed at Michigan Technological University to correlate subsurface data by utilizing …


Deviance Information Criterion For Comparing Stochastic Volatility Models, Andreas Berg, Renate Meyer, Jun Yu Jan 2004

Deviance Information Criterion For Comparing Stochastic Volatility Models, Andreas Berg, Renate Meyer, Jun Yu

Research Collection School Of Economics

Bayesian methods have been efficient in estimating parameters of stochastic volatility models for analyzing financial time series. Recent advances made it possible to fit stochastic volatility models of increasing complexity, including covariates, leverage effects, jump components, and heavy-tailed distributions. However, a formal model comparison via Bayes factors remains difficult. The main objective of this article is to demonstrate that model selection is more easily performed using the deviance information criterion (DIC). It combines a Bayesian measure of fit with a measure of model complexity. We illustrate the performance of DIC in discriminating between various different stochastic volatility models using simulated …


Java-Based Digital Library Portal For Geography Education, Zehua Liu, Hai Yuan, Ee Peng Lim, Ming Yin, Dion Hoe-Lian Goh, Yin-Leng Theng, Wee-Keong Ng Jan 2004

Java-Based Digital Library Portal For Geography Education, Zehua Liu, Hai Yuan, Ee Peng Lim, Ming Yin, Dion Hoe-Lian Goh, Yin-Leng Theng, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

G-Portal is a Java-based digital library system for managing the metadata of geography related resources on the Web. In addition to providing a flexible repository subsystem to accommodate metadata of different formats using XML and XML Schemas, G-Portal organizes metadata into projects and layers, and supports an integrated and synchronized classification and map-based interfaces over the stored metadata. G-Portal also includes a classification subsystem that creates category structures and classifies metadata resources into categories based on user-specified classification schemas. Furthermore, G-Portal users can annotate resources and make their annotations available to others. In this paper, we describe the design and …


Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan Jan 2004

Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan

Research Collection School Of Computing and Information Systems

This paper describes the routing problems in optical fiber networks, defines five constraints, induces and simplifies the evaluation function and fitness function, and proposes a routing approach based on the genetic algorithm, which includes an operator [OMO] to solve the QoS routing problem in optical fiber communication networks. The simulation results show that the proposed routing method by using this optimal maintain operator genetic algorithm (OMOGA) is superior to the common genetic algorithms (CGA). It not only is robust and efficient but also converges quickly and can be carried out simply, that makes it better than other complicated GA.


Evaluating The Usability Of A Group Support System Using Co-Discovery, Keng Siau Jan 2004

Evaluating The Usability Of A Group Support System Using Co-Discovery, Keng Siau

Research Collection School Of Computing and Information Systems

Group Support Systems (GSSs) have emerged as a new type of information system to aid group decision-making. With the proliferation of such systems in organizations, evaluation of GSSs is becoming increasingly important. This paper reports the evaluation of an existing GSS. Our usability framework consists of nine dimensions: visual clarity, consistency, compatibility, informative feedback, explicitness, flexibility and control, error prevention and correction, ease of learning, and ease of use. We make use of the co-discovery method where teams of two participants perform tasks together while being observed. The study involves questionnaires and interview sessions. The strengths and weaknesses of the …


Web Usage Mining: Algorithms And Results, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng Jan 2004

Web Usage Mining: Algorithms And Results, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

No abstract provided.


Logistics Outsourcing And 3pl Challenges, Michelle L. F. Cheong Jan 2004

Logistics Outsourcing And 3pl Challenges, Michelle L. F. Cheong

Research Collection School Of Computing and Information Systems

Logistics has been an important part of every economy and every business entity. The worldwide trend in globalization has led to many companies outsourcing their logistics function to Third-Party Logistics (3PL) companies, so as to focus on their core competencies. This paper attempts to broadly identify and categorize the challenges faced by 3PL companies and discover potential gaps for future research. Some of the challenges will be related with the experience and information collected from interviews with two 3PL companies.


A Secure And Privacy Enhanced Location-Based Service Transaction Protocol In Ubiquitous Computing Environment, Konidala Divyan, Robert H. Deng, Jianying Zhou, Kwanjo Kim Jan 2004

A Secure And Privacy Enhanced Location-Based Service Transaction Protocol In Ubiquitous Computing Environment, Konidala Divyan, Robert H. Deng, Jianying Zhou, Kwanjo Kim

Research Collection School Of Computing and Information Systems

Nowadays mobile phones and PDAs are part and parcel of our lives. By carrying a portable mobile device with us all the time we are already living in partial Pervasive Computing Environment (PCE) that is waiting to be exploited very soon. One of the advantages of pervasive computing is that it strongly supports the deployment of Location-Based Service(s) (LBSs). In PCE, there would be many competitive service providers (SPs) trying to sell different or similar LBSs to users. In order to avail a particular service, it becomes very di#cult for a low-computing and resourcepoor mobile device to handle many such …