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

Digital Commons Network™

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

1999

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 4591 - 4620 of 6124

Full-Text Articles in Entire DC Network

Fast Algorithms For Wavelet-Based Analysis Of Hyperspectral Signatures, Jiang Li Jan 1999

Fast Algorithms For Wavelet-Based Analysis Of Hyperspectral Signatures, Jiang Li

UNLV Retrospective Theses & Dissertations

Hyperspectral sensors promise great improvements in the quality of information gathered for remote sensing applications. However, they also present a huge challenge to data storage and computing systems. Thus there is a great need for reliable compression schemes, as well as analysis tools that can exploit the hyperspectral data in a computationally efficient manner. It has been proposed that wavelet-based methods may be superior to currently used methods for the analysis of hyperspectral signatures. In this thesis, a wavelet-based method, as well as traditional analytical methods, was implemented and applied to hyperspectral images. The computational expense of the various methods …

Go to article

Ethical Climates In Lodging Operations: An Exploratory Study Of Management Perceptions, Todd Isaac Weinstein Jan 1999

Ethical Climates In Lodging Operations: An Exploratory Study Of Management Perceptions, Todd Isaac Weinstein

UNLV Retrospective Theses & Dissertations

This study explored the role of ethics in lodging organizations. Managers working at five different properties constituted the survey sample. The study examined management perceptions as measured by the Ethical Climate Questionnaire (ECQ). This instrument, used in previous research on moral reasoning, is designed to assess the perceptions of respondents based on three categories in two separate dimensions: ethical criteria (egoism, benevolence and principle) and loci of analysis (individual, local, and cosmopolitan). Each category comprises a separate ethical climate. Results from the ECQ were compared to various demographic variables such as gender, age, years of management experience, and number of …

Go to article

Automated Stenosis Quantification In Coronary Arteriograms, Yu Zhang Jan 1999

Automated Stenosis Quantification In Coronary Arteriograms, Yu Zhang

UNLV Retrospective Theses & Dissertations

Computer-assisted techniques have been shown to be useful in estimating the diameter and cross-sectional area of coronary artery lesions. In this study, two different strategies are employed for identification of artery contours, i.e., scanning and tracKing The scanning approach is accomplished by a canny edge detector. The edge tracking approach is in favor due to its low variability and fast analysis time. Given a start point and search direction, a tracking process automatically detects the arteries edge. From the edge points, a quantitative analysis process calculates the arteries diameter and percent diameter stenosis. As the software runs within a second, …

Go to article

The Use Of Continuum Models For Conducting Both Linear And Nonlinear Analyses Of Lattice Structures, Simon Yi Luk Jan 1999

The Use Of Continuum Models For Conducting Both Linear And Nonlinear Analyses Of Lattice Structures, Simon Yi Luk

UNLV Retrospective Theses & Dissertations

Large structural projects, such as lattices for framing tall buildings or space purpose can result in huge finite element models. The use of continuum methodology for conducting both linear and nonlinear analyses of lattice structures in finite-element models results in significantly fewer degrees of freedom than discrete finite-element models, which individually model each structural element. Hence, the use of continuum models can result in a considerable reduction in computational effort with a corresponding savings in cost, at least during early 1990s when Pentium computer was not available. Now, it can still be a good design method especially for tall buildings …

Go to article

Midpoint Estimation Applied To The Vertical-Horizontal Illusion, Gary Wayne Ogren Jan 1999

Midpoint Estimation Applied To The Vertical-Horizontal Illusion, Gary Wayne Ogren

UNLV Retrospective Theses & Dissertations

Eighty-three college undergraduates estimated midpoints of vertical lines presented in cued (a letter or figure presented below the line), uncued, and inverted T conditions. Subject's mean estimates were near the geometric midpoint in the two cued conditions, and significantly above the midpoint in the uncued and inverted T conditions. Mean estimates in the inverted T conditions were significantly above those in the uncued condition. These displacements are discussed in relation to previous midpoint estimation findings and theoretical explanations of the vertical-horizontal illusion. The midpoint estimation task is evaluated as an investigative tool in studies of geometric-optical illusions, and recommendations for …

Go to article

Responses Of Python Regius To Animal Chemosensory Stimuli: Implications Of Foraging Ecology, Albert Klein Jan 1999

Responses Of Python Regius To Animal Chemosensory Stimuli: Implications Of Foraging Ecology, Albert Klein

UNLV Retrospective Theses & Dissertations

Python regius is considered to be a sit-and-wait forager and has been reported to attempt capture of live and dead homeothermic prey. This preference for homeothermic prey may be innate and is not dependent on thermal cues. Chemosensory stimuli appear to be the only stimuli which may indicate to P. regius the metabolic group that a dead prey item at room temperature item may belong to. Snakes were exposed to novel odors from homeothermic and poikilothermic animals. Prey Searching Behavior (amount of locomotion) and Information Gathering Behavior (tongue flicking) were observed. Habituation to odors resulted in decreased behaviors. Odors of …

Go to article

A 3-Dimensional H-Adaptive Algorithm For Groundwater Flow And Contaminant Transport, Lan Li Jan 1999

A 3-Dimensional H-Adaptive Algorithm For Groundwater Flow And Contaminant Transport, Lan Li

UNLV Retrospective Theses & Dissertations

The simulation of contaminant transport through the subsurface is a very useful way to effectively design mitigation methods for cleanup and prevention of the deterioration of groundwater; The GWADAPT3 code is developed using the finite-element method and mesh adaptation to simulate groundwater flow and contaminant transport. The formulation is based on the equations for conservation of mass, Darcy's law for an anisotropic medium, and the time-dependent species transport equations. Petrov-Galerkin weighting of the advection terms provides numerical stability. An explicit time marching scheme is used to solve the transient equations. By utilizing unstructured adaptive meshing, concentration is accurately resolved; Benchmark …

Go to article

A Comparison Of Fast And Slow Contraction Speeds Using Electromyography, Philip James Melhorn Jan 1999

A Comparison Of Fast And Slow Contraction Speeds Using Electromyography, Philip James Melhorn

UNLV Retrospective Theses & Dissertations

The purpose of this study was to determine if differences in EMG activity existed between fast and slow contraction speeds during isolated, one-armed biceps curls to muscle failure. Participants performed one set of biceps curls to muscular failure on two separate occasions at different contraction speeds. Constant load equal to 75% of 1RM was used for each test. The dependent variables were integrated EMG (iEMG), percent change in mean frequency, and time to muscular failure. Integrated EMG measurements revealed significantly greater muscle activity for the slow contractions (t = 4.76, p {dollar}<{dollar}.001). The time to muscular failure also showed significant differences having the fast contraction speed achieve muscle failure faster than the slow contraction speed (t = 5.23, p {dollar}<{dollar}.001). The comparison of frequency data failed to reach significance. A significant correlation (r =.514) was determined for iEMG and time to muscular failure. These results suggest that differences exist in iEMG and time to muscle failure between fast and slow contraction speeds.

Go to article

The Aerodynamic Response Of Airborne Discs, Timothy Lewis Mitchell Jan 1999

The Aerodynamic Response Of Airborne Discs, Timothy Lewis Mitchell

UNLV Retrospective Theses & Dissertations

A study has been conducted to characterize the flow over a free-flying disc. In this study, three types of discs are analyzed in a series of stationary experiments, and a single disc is analyzed in a spinning experiment. Two dimensionless parameters dominate the experiments, the Reynolds number and the tip speed ratio. The first experiment measured the lift and drag at varying angles of attack on a stationary disc. The second stationary experiment was a unique measurement of the center of lift of a disc as a function of velocity. The third stationary experiment was a tuft test to describe …

Go to article

A Heuristic Approach For Path Planning For Redundant Robots, George Petrescu Jan 1999

A Heuristic Approach For Path Planning For Redundant Robots, George Petrescu

UNLV Retrospective Theses & Dissertations

A new method to solve the trajectory generation for a redundant manipulator is proposed. It avoids traditional computationally intensive methods by relying on the human experience; The proposed method uses a fuzzy logic controller to generate the magnitude of the angles needed to move the end effector to the next target point. The inputs to the controller are the desired displacement of the end effector and the elements of the jacobian matrix that correspond to the considered joint, while the output is the angle magnitude of the joint needed to reach the target point; An algorithm is used to determine …

Go to article

Experimental Study Of Drying Of A Porous Medium At Sub-Residual Saturations, Adaikkalavan Kumar Sathappan Jan 1999

Experimental Study Of Drying Of A Porous Medium At Sub-Residual Saturations, Adaikkalavan Kumar Sathappan

UNLV Retrospective Theses & Dissertations

An experimental study has been conducted to understand the drying effects in sub-residual saturated systems. Different flow rates and isothermal wall temperatures were used in the experiments. In two experimental runs, the test section was maintained at room temperature and gas flow initiated. Four other cases were started initially with heating up the porous medium with no flow, and then letting nitrogen gas flow through the test-section after a steady-state temperature distribution had been reached (denoted in what follows as the "steady heating case"); Temperatures throughout the bed and entering and exiting humidity values as a function of time among …

Go to article

Soluble Mineral Content Of Soils Using Electrical Conductivity, Merrill Gene Schweppe Jan 1999

Soluble Mineral Content Of Soils Using Electrical Conductivity, Merrill Gene Schweppe

UNLV Retrospective Theses & Dissertations

Soils with soluble salts occur in semi-arid and arid regions worldwide. The soluble mineral percentage of soil is determined by measuring the weight lost by diluting the soil mass with a fixed quantity of water. Correct estimation of soluble mineral content is made at the point of unsaturation. In the absence of clay, grain size does not affect determination of electrical conductivity for soils. Measurement of the electrical conductivity for a series of dilution ratios provides a reliable means of determining the correct dilution ratio. Measurement of the electrical conductivity of a subset of low water-soil dilution ratios and a …

Go to article

Classification Of Galaxies Using Fractal Dimensions, Sandip G Thanki Jan 1999

Classification Of Galaxies Using Fractal Dimensions, Sandip G Thanki

UNLV Retrospective Theses & Dissertations

The classification of galaxies is morphological. Shapes of the galaxies range from the very simple (e.g. elliptical galaxies) to the highly complex (e.g. irregular galaxies). Analyzing a measure of complexity for such shapes could lead to automatic classification. Fractal dimension, a quantity related to the complexity of a given shape, could be such a measure. Capacity dimension and correlation dimension are two of the several types of fractal dimensions. In this project, correlation dimensions and the capacity dimensions of the contours generated around different intensity levels of the galaxy images, versus the intensity levels were computed. It was found that …

Go to article

Impacts Of Stock Prices And Interest Rates On Tourism Consumption, Ming-Chih Tsai Jan 1999

Impacts Of Stock Prices And Interest Rates On Tourism Consumption, Ming-Chih Tsai

UNLV Retrospective Theses & Dissertations

Tourism industry has emerged as a leader in the U.S.'s service economy in the last decade. Meanwhile, stock markets and interest rates have been playing a more important role in Americans everyday lives. Prior research mainly focused on the economic impact of travel and tourism industry, but there are very few studies regarding how changes in economic factors will affect domestic tourism industry. This study focuses on measuring the impacts of stock prices and interest rates on tourism consumption. The results of this study show that stock prices and interest rates do have a certain amount of impacts on people's …

Go to article

Control Of Flexible Joint Robotic Manipulator Using Tuning Functions Design, Pavan Krishna Aripirala Venkata Jan 1999

Control Of Flexible Joint Robotic Manipulator Using Tuning Functions Design, Pavan Krishna Aripirala Venkata

UNLV Retrospective Theses & Dissertations

The goal of this thesis is to design the controller for a single arm manipulator having a flexible joint for the tracking problem in two different cases. A controller is designed for a deterministic case wherein the plant parameters are assumed to be known while another is designed for an adaptive case where all the plant parameters are assumed to be unknown. In general the tracking problem is; given a smooth reference trajectory, the end effector has to track the reference while maintaining the stability. It is assumed that only the output of the manipulator, which is the link angle, …

Go to article

Modeling Of Short-Distance Running, Maria Camille Theresa Jose Capiral Jan 1999

Modeling Of Short-Distance Running, Maria Camille Theresa Jose Capiral

UNLV Retrospective Theses & Dissertations

In this thesis, we construct a model of human performance in short distance foot races. First, we describe the Hill-Keller model of competitive running, based on the solution to an optimal control problem, and then focus on that part of the model dealing with short distance races. Our task is to estimate two underlying physiological parameters that characterize the runner's performance. Second, we customize this submodel by linearizing Keller's analytical solution for short distance races, we then apply a high quality linear least squares estimation based on the Singular Value Decomposition (SVD) in order to estimate the two physiological parameters. …

Go to article

Theoretical Study Of Mbe Growth Of Indium Gallium Arsenide Semiconductor Compound On Gallium Arsenide Substrate, Golshan Colayni Jan 1999

Theoretical Study Of Mbe Growth Of Indium Gallium Arsenide Semiconductor Compound On Gallium Arsenide Substrate, Golshan Colayni

UNLV Retrospective Theses & Dissertations

The theoretical study of Molecular Beam Epitaxy allows us to model and construct an experiment with the same conditions. Growth modeling investigates compound semiconductor characteristics during the MBE growth which can achieve the best results to control the quality of growth. Growth modeling also is less expensive and faster than experiments. The wide variation in the band-gap and lattice constants between InAs and GaAs is a subject for a variety of optical and electronic device applications involving InGaAs/GaAs systems. In this material system, the perfection is intrinsically controlled by the surface segregation of In due to its larger atomic size …

Go to article

Fluid Flow And Slope Stability Model, Gene Cotner Jan 1999

Fluid Flow And Slope Stability Model, Gene Cotner

UNLV Retrospective Theses & Dissertations

The objective of this work was to develop a computer model to calculate the changes in factor of safety of a slope with time resulting from changes in the water saturation. A two-phase fluid flow model was incorporated to calculate the saturation and saturation changes in fractured and nonfractured soil and rock. A slope stability model was created to calculate the factor of safety. The fluid flow module executes for every time interval specified by the user. The slope stability module is executed at the end of any time interval when desired. As examples, factors of safety for the downstream …

Go to article

The Relationship Between Casino Drop And Gaming Stock Performance: A Multivariate Analysis, Mark H Gilbert Jan 1999

The Relationship Between Casino Drop And Gaming Stock Performance: A Multivariate Analysis, Mark H Gilbert

UNLV Retrospective Theses & Dissertations

In reference to the gaming industry, investors and analysts examine many different variables that affect the financial viability of the business. Areas of investigation have included competition, governmental regulation, debt structure, cash flow, visitor volume, and so on; The purpose of this study was to analyze the relationship of yet another variable of casino performance, the casino drop, to gaming stock performance. Utilizing statistics provided from the State of Nevada's Gaming Revenue Report, the casino drop was divided into five segments, blackjack, craps, baccarat, quarter slots, and dollar slots; Tested by using a multiple regression analysis against a market capitalization-weighted …

Go to article

Do Rna-Dependent Polymerases Share Common Ancestry? A Bioinformatic Approach, Julianna Hudak Jan 1999

Do Rna-Dependent Polymerases Share Common Ancestry? A Bioinformatic Approach, Julianna Hudak

UNLV Retrospective Theses & Dissertations

Bioinformatics is the use of computational methods to perform hypothesis-driven research that generates new knowledge from existing biological databases. For any bioinformatic analysis, it is important that the most accurate method(s) be used. The first portion of this thesis is a comparative evaluation of six programs designed for the local alignment of protein sequences. The results demonstrate that two of the programs, MEME and PROBE, outperform all other programs (BLOCKMAKER, ITERALIGN, MATCHBOX, and PIMA). The second portion of this thesis uses MEME and PROBE in an attempt to locate an ordered-series-of-motifs (OSM) among two groups of RNA-dependent polymerases, the large …

Go to article

A Parametric Study On The Contained Burning Of Solid Rocket Motor Propellant, Jennifer Erin Politano Jan 1999

A Parametric Study On The Contained Burning Of Solid Rocket Motor Propellant, Jennifer Erin Politano

UNLV Retrospective Theses & Dissertations

Outmoded solid rocket motor propellant is being destroyed by burning as part of the worldwide demilitarization process. Many of these bums have been performed in spaces where the combustion products are contained within a sealed chamber. There is currently no accepted method to predict the gas temperature and pressure that results from this process. The primary focus of this study was the prediction of the peak temperature and pressure of the gas inside an underground containment chamber as a function of the propellant consumed and the prediction of the wall surface temperature as a function of time; A thermodynamic lumped …

Go to article

The Selection And Preparation Of Paramedic Preceptors In Emergency Medical Services, Brian James Tilton Jan 1999

The Selection And Preparation Of Paramedic Preceptors In Emergency Medical Services, Brian James Tilton

UNLV Retrospective Theses & Dissertations

In Emergency Medical Services, training programs for paramedics, providers of Advanced Life Support emergency care, include a field internship where students are partnered with a preceptor for training and evaluation before program completion; The purpose of this study was to determine if certain attributes could be used as predictors for preceptor success measured by a preceptor performance evaluation. The quantitative descriptive, correlation study was based on data gathered from paramedic preceptors in Clark County, Nevada in the spring of 1999. The sample (n = 66) was drawn through a consensus survey of every paramedic preceptor employed by a provider agency …

Go to article

Using Cottonwoods As Indicators Of Past Floods Along A Gravel-Bedded Stream, Edward A. Watson Jan 1999

Using Cottonwoods As Indicators Of Past Floods Along A Gravel-Bedded Stream, Edward A. Watson

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

Go to article

A Monte Carlo Comparison Of Tests For Cointegration In Panel Data, Chihwa Kao Jan 1999

A Monte Carlo Comparison Of Tests For Cointegration In Panel Data, Chihwa Kao

Center for Policy Research

This paper surveys recent developments and provides Monte Carlo comparison on various tests proposed for cointegration in panel data. In particular, tests for two panel models, varying intercepts and varying slopes, and varying intercepts and common slopes are presented from the literature with a total of seven tests being simulated. In all cases, results on empirical size and size-adjusted power are given.

Go to article

On The Estimation And Inference Of A Cointegrated Regression In Panel Data, Chihwa Kao Jan 1999

On The Estimation And Inference Of A Cointegrated Regression In Panel Data, Chihwa Kao

Center for Policy Research

The main contribution of this paper is to add to the literature by suggesting a dynamic OLS (DOLS) estimator and providing a serious comparison of the finite sample properties of the OLS, fully modified OLS (FMOLS), and DOLS estimators in panel cointegrated regression models. Monte Carlo results illustrate the sampling behavior of the proposed estimators and show that (1) the OLS estimator has a non-negligible bias in finite samples, (2) the FMOLS estimator does not improve over the OLS estimator in general, and (3) the DOLS outperforms both the OLS and FMOLS estimators.

Go to article

The L5/S1 Joint Moment Sensitivity To Measurement Errors In Dynamic 3d Multisegment Lifting Models, Christian Larivière, Denis Gagnon Jan 1999

The L5/S1 Joint Moment Sensitivity To Measurement Errors In Dynamic 3d Multisegment Lifting Models, Christian Larivière, Denis Gagnon

Études primaires

No abstract provided.

Go to article

Activities Of Daily Living In Heart Transplant Candidates., John David Putzke Jan 1999

Activities Of Daily Living In Heart Transplant Candidates., John David Putzke

All ETDs from UAB

No abstract provided.

Go to article

Natalie Vivian Scott: The Origins, People And Times Of The French Quarter Renaissance (1920-1930)., John Wyeth Scott Ii Jan 1999

Natalie Vivian Scott: The Origins, People And Times Of The French Quarter Renaissance (1920-1930)., John Wyeth Scott Ii

LSU Historical Dissertations and Theses

This is the interwoven story of Natalie Vivian Scott, war hero, author, adventurer and humanitarian, and the French Quarter Renaissance during the 1920s, when Natalie Scott was a vital member of the talented coterie of writers and artists whose talents prospered there, including Sherwood Anderson, William Faulkner, William Spratling, Lyle Saxon, Roark Bradford, Oliver La Farge, John Dos Passos, Hamilton Basso, Meigs Frost, among others. This work's premise is that the decayed, crumbling French Quarter, falling into irreversible decline, was saved during the early 1920s by an outburst of local creativity and organizational energy that inspired restoration and a unique, …

Go to article

Design Recovery And Data Mining: A Methodology That Identifies Data-Cohesive Subsystems Based On Mining Association Rules., Carlos Montes De Oca Jan 1999

Design Recovery And Data Mining: A Methodology That Identifies Data-Cohesive Subsystems Based On Mining Association Rules., Carlos Montes De Oca

LSU Historical Dissertations and Theses

Software maintenance is both a technical and an economic concern for organizations. Large software systems are difficult to maintain due to their intrinsic complexity, and their maintenance consumes between 50% and 90% of the cost of their complete life-cycle. An essential step in maintenance is reverse engineering, which focuses on understanding the system. This system understanding is critical to avoid the generation of undesired side effects during maintenance. The objective of this research is to investigate the potential of applying data mining to reverse engineering. This research was motivated by the following: (1) data mining can process large volumes of …

Go to article

Spatial Modeling Of Coastal Landscapes: Methodological And Scientific Applications., Mary Louise White Jan 1999

Spatial Modeling Of Coastal Landscapes: Methodological And Scientific Applications., Mary Louise White

LSU Historical Dissertations and Theses

A number of issues related to landscape scale ecological modeling of the wetlands of southern Louisiana are examined in this study. First, using geostatistical methods, a new contour map of the wetland habitats in the Terrebonne basin of southern Louisiana is constructed from data collected in 1994. This map is proposed as the best field verified habitat map of the Terrebonne basin and contains statistical confidence intervals associated with the habitat contours. Second, the problem of how to evaluate the success of a landscape model prediction is investigated. The multiple resolution goodness of fit parameter Ft(k) is evaluated in detail …

Go to article

First Prev Next Last