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

Physical Sciences and Mathematics Commons

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

2009

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 3031 - 3060 of 7616

Full-Text Articles in Physical Sciences and Mathematics

Acceleration Methodology For The Implementation Of Scientific Applications On Reconfigurable Hardware, Phillip Martin May 2009

Acceleration Methodology For The Implementation Of Scientific Applications On Reconfigurable Hardware, Phillip Martin

All Theses

The role of heterogeneous multi-core architectures in the industrial and scientific computing community is expanding. For researchers to increase the performance of complex applications, a multifaceted approach is needed to utilize emerging reconfigurable computing (RC) architectures. First, the method for accelerating applications must provide flexible solutions for fully utilizing key architecture traits across platforms. Secondly, the approach needs to be readily accessible to application scientists. A recent trend toward emerging disruptive architectures is an important signal that fundamental limitations in traditional high performance computing (HPC) are limiting break through research. To respond to these challenges, scientists are under pressure to …


A Dual Algorithm For The Weighted Euclidean Distance Min-Max Location Problem In R^2 And R^3, Andrea Smith May 2009

A Dual Algorithm For The Weighted Euclidean Distance Min-Max Location Problem In R^2 And R^3, Andrea Smith

All Theses

A dual approach algorithm is given for the solution of the weighted min-max location problem with Euclidean distance in R^2 and R^3. Each subproblem is solved using a directional search procedure and by taking advantage of its geometric structure. An algebraic replacement rule is employed to update the subproblem.


Testing The Individual Effective Dose Hypothesis, Hung Vu May 2009

Testing The Individual Effective Dose Hypothesis, Hung Vu

All Theses

The assumption of the individual effective dose is the basis for the probit method used for analyzing dose or concentration – response data. According to this assumption, each individual has a uniquely innate tolerance expressed as the individual effective dose (IED) or the smallest dose that is sufficient to kill it. An alternative to IED, stochasticity suggests that individuals do not have uniquely innate tolerance; deaths result from random processes occurring among similar individuals. While the probit method has been used extensively in toxicology the underlying assumption has not been tested rigorously. The goal of this study was to test …


Ocular Vergence Response Over Anaglyphic Stereoscopic Videos, Brian Daugherty May 2009

Ocular Vergence Response Over Anaglyphic Stereoscopic Videos, Brian Daugherty

All Theses

The effect of anaglyphic stereographic stimuli on ocular vergence response is examined. An experiment is performed comparing ocular vergence response induced by anaglyphic stereographic display versus standard monoscopic display. Two visualization tools, synchronized three-dimensional scanpath playback and real-time dynamic heatmap generation,
are developed and used to subjectively support the quantitative analysis of ocular disparity. The results of a one-way ANOVA indicate that there is a highly significant effect of anaglyphic stereoscopic display on ocular vergence for a majority of subjects although consistency of vergence response is difficult to predict.


On Mining Rating Dependencies In Online Collaborative Rating Networks, Hady W. Lauw, Ee Peng Lim, Ke Wang May 2009

On Mining Rating Dependencies In Online Collaborative Rating Networks, Hady W. Lauw, Ee Peng Lim, Ke Wang

Research Collection School Of Computing and Information Systems

The trend of social information processing sees e-commerce and social web applications increasingly relying on user-generated content, such as rating, to determine the quality of objects and to generate recommendations for users. In a rating system, a set of reviewers assign to a set of objects different types of scores based on specific evaluation criteria. In this paper, we seek to determine, for each reviewer and for each object, the dependency between scores on any two given criteria. A reviewer is said to have high dependency between a pair of criteria when his or her rating scores on objects based …


Are Online Auction Markets Efficient? An Empirical Study Of Market Liquidity And Abnormal Returns., Robert J. Kauffman, Trent J Spaulding, Charles A. Wood May 2009

Are Online Auction Markets Efficient? An Empirical Study Of Market Liquidity And Abnormal Returns., Robert J. Kauffman, Trent J Spaulding, Charles A. Wood

Research Collection School Of Computing and Information Systems

Technological advances have facilitated investment in collectibles through online auction markets, where information regarding product characteristics, current and historical prices, and product availability is available to millions of market participants. However, market inefficiencies may still exist, where prices do not reflect market information and where savvy speculators can profit. Using unit root and variance ratio tests, we examine 8538 rare stamp and 56,997 rare coin auctions to evaluate the efficiency of online markets. In particular, we study market liquidity, abnormal returns and weak-form efficiency. We find an inverse relationship between market efficiency and liquidity. Bidder competition intrinsic to liquidity increases …


Constraint-Based Dynamic Programming For Decentralized Pomdps With Structured Interactions, Akshat Kumar, Shlomo Zilberstein May 2009

Constraint-Based Dynamic Programming For Decentralized Pomdps With Structured Interactions, Akshat Kumar, Shlomo Zilberstein

Research Collection School Of Computing and Information Systems

Decentralized partially observable MDPs (DEC-POMDPs) provide a rich framework for modeling decision making by a team of agents. Despite rapid progress in this area, the limited scalability of solution techniques has restricted the applicability of the model. To overcome this computational barrier, research has focused on restricted classes of DEC-POMDPs, which are easier to solve yet rich enough to capture many practical problems. We present CBDP, an efficient and scalable point-based dynamic programming algorithm for one such model called ND-POMDP (Network Distributed POMDP). Specifically, CBDP provides magnitudes of speedup in the policy computation and generates better quality solution for all …


Ss-Ids: Statistical Signature Based Ids, Payas Gupta, Chedy Raissi, Gerard Dray, Pascal Poncelet, Johan Brissaud May 2009

Ss-Ids: Statistical Signature Based Ids, Payas Gupta, Chedy Raissi, Gerard Dray, Pascal Poncelet, Johan Brissaud

Research Collection School Of Computing and Information Systems

Security of web servers has become a sensitive subject today. Prediction of normal and abnormal request is problematic due to large number of false alarms in many anomaly based Intrusion, Detection Systems(IDS). SS-IDS derives automatically the parameter profiles from the analyzed data thereby generating the Statistical Signatures. Statistical Signatures are based on modeling of normal requests and their distribution value without explicit intervention. Several attributes are used to calculate the behavior of the legitimate request on the web server. SS-IDS is best suited for the newly installed web servers which doesn't have low gene number of requests in. the data …


Improving Success Of Translocating Southern Idaho Ground Squirrels (Spermophilus Endemicus), Katie Lea Busscher May 2009

Improving Success Of Translocating Southern Idaho Ground Squirrels (Spermophilus Endemicus), Katie Lea Busscher

Boise State University Theses and Dissertations

Populations of the southern Idaho ground squirrel (Spermophilus endemicus; SIDGS), a federally listed candidate species, have declined in the last 30 years mainly because of habitat degredation, loss, and fragmentation. As a management tool, translocation is commonly used to augment, establish, or re-establish wildlife populations, although translocation has historically not been the most successful conservation strategy for species that are threatened or endangered animals as a result of habitat loss. I employed various techniques to improve translocation success of southern Idaho ground squirrels. To establish new populations, I relocated SIDGS to areas within their native range not already occupied by …


Implementation Of A Cartesian Grid Incompressible Navier-Stokes Solver On Multi-Gpu Desktop Platforms Using Cuda, Julien C. Thibault May 2009

Implementation Of A Cartesian Grid Incompressible Navier-Stokes Solver On Multi-Gpu Desktop Platforms Using Cuda, Julien C. Thibault

Boise State University Theses and Dissertations

Today’s Graphics Processor Units (GPU) are powerful computation platforms used not only for graphic rendering but also for multi-purpose computation. Now reaching a teraflops of peak performance and over a 100 GB/sec of bandwidth, GPUs outperform the latest CPUs and provide a new high-performance computing platform. New languages such as CUDA and Brook+ allow developers to target the programmable unit of the GPUs without a graphics programming background. Scientists and engineers in various fields have started benefiting from the last generations of GPUs. In this thesis, the implementation of a Navier-Stokes solver for incompressible flow around urban-like domains is presented. …


Effective Sample Size In Order Statistics Of Correlated Data, Neill Mcgrath May 2009

Effective Sample Size In Order Statistics Of Correlated Data, Neill Mcgrath

Boise State University Theses and Dissertations

In this study we address the problem of using effective sample size (ESS) to approximate the probability distributions of order statistics from correlated data. We present these approximations and determine their accuracy through simulation studies. More often than not, correlation exists between data points in a set of data. When we use the original sample size of the data in a derivation of a model of the data, we automatically assume that each data point contains one data point's worth of information. If the data are correlated, then each data point contains less than one data point's worth of information …


Performance Of Upham Beach T-Groin Project And Its Impact To The Downdrift Beach, Ping Wang, Tiffany M. Roberts May 2009

Performance Of Upham Beach T-Groin Project And Its Impact To The Downdrift Beach, Ping Wang, Tiffany M. Roberts

Geology Faculty Publications

The field of 5 T-groins installed at Upham Beach was designed to maintain a portion of the nourished beach at this chronically eroding location without negative impacts to the downdrift beach. The T-groin project area was renourished in September 2006 and all the structures were buried. During the initial 3 months after the nourishment, rapid beach erosion at the north segment, as typical of Upham Beach, was measured. Since all the structures were buried, this rapid erosion should not be directly related to the T-groin field. The downdrift beach remained largely stable to slightly accretionary, benefiting from the sand supply …


The Synthesis And Systematic Evaluation Of Modified Polymeric Foams And Electrically Conductive Polyimide/Carbon/Metal Films, John Macharia Kinyanjui May 2009

The Synthesis And Systematic Evaluation Of Modified Polymeric Foams And Electrically Conductive Polyimide/Carbon/Metal Films, John Macharia Kinyanjui

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thermally processed PU foams are examined as a function of processing temperatures (25, 45, 65, and 85°C) at the side, middle, and center of a simple cylindrical mold. The PU foams show both chemical and morphological differences as a function of the processing temperature and radial position within the mold. Thermal degradation of uretoneimine structures, the emergence of carbodiimide structures, and extent of reaction of isocyanate groups are measured using photoacoustic FTIR spectroscopy. Chemical gradients and morphology differences between the side, middle, and center of the molded foam are observed for all processing temperatures. The data indicate that thermal activation …


The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum May 2009

The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focuses on two issues in enhanced biological phosphorus removal (EBPR). The first issue encompasses the effect of the type of carbon sources (i.e. volatile fatty acids and non volatile fatty acids) on the microbiology of EBPR. The second issue deals with the influence of denitrification on EBPR. Few studies have been performed to investigate these two issues. The recent findings on these areas are summarized below to establish the knowledge gaps this dissertation attempted to address. Details on the specific findings can be found in the literature review portion of this proposal.


Flowing Toward Sustainability: Two Stream Adjudications Analyzed Under The Iad Framework, Nancye Lou Bethurem May 2009

Flowing Toward Sustainability: Two Stream Adjudications Analyzed Under The Iad Framework, Nancye Lou Bethurem

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the most significant problems impacting the western United States today is the lack of naturally occurring water resources, especially during this period of drought and explosive population growth. This has led to intense competition over water use and ownership in the arid and semi-arid regions of the United States. During this period of water resource scarcity, it is extremely important to determine the ownership of water rights in order to implement optimal management systems. Most western states use a system of "general stream adjudications" to make water rights ownership determinations.

General stream adjudications are legal proceedings used to …


Case Study: Feasibility Analysis Of Renewable Energy Supply Systems In A Small Grid Connected Resort, Jody Robins May 2009

Case Study: Feasibility Analysis Of Renewable Energy Supply Systems In A Small Grid Connected Resort, Jody Robins

UNLV Theses, Dissertations, Professional Papers, and Capstones

This paper presents a case study on the feasibility of a small grid connected resort in the marine west coast climate of Canada to implement a renewable energy supply system. The current industry conditions of three renewable energy systems are explored including small and large wind energy conversion systems, solar photovoltaic cell systems, and energy cell systems. Furthermore, these three systems are evaluated using the power load, wind, and solar radiation information from a specific resort. The renewable energy source assessment and optimization software HOMER (National Renewable Energy Laboratory, US) is used to evaluate the costs and benefits of each …


Imaging Second-Harmonic Radiation And Scattering Patterns In Zno Micro/Nanostructures, Katrina Marie Geren May 2009

Imaging Second-Harmonic Radiation And Scattering Patterns In Zno Micro/Nanostructures, Katrina Marie Geren

Graduate Theses and Dissertations

The optical characteristics of ZnO nanostructures have recently garnered interest due to the inclusion of these structures in many nanoscale optical and optoelectronic devices. This thesis will address several characteristics involving second harmonic generation and scattering in ZnO nano- and microstructures. A method will be presented for determining the nonlinear coefficients of the second order susceptibility in a single ZnO rod. This method uses transmission geometry where previous methods have employed back-reflected irradiation. The nonlinear coefficients found using this new technique were consistent with previous data from similar structures. Models will be presented for predicting the second harmonic scattering patterns …


Modeling Of Compositionally Graded Barium Strontium Titanate From First Principles, Laura Elizabeth Walizer May 2009

Modeling Of Compositionally Graded Barium Strontium Titanate From First Principles, Laura Elizabeth Walizer

Graduate Theses and Dissertations

"Barium Strontium Titanate (BaxSr1-xTiO3 or BST) is a Perovskite alloy of interest for both technological and intellectual reasons. Its ferroelectric and piezoelectric properties make it useful in a variety of electric components such as transducers and actuators, and BST in particular is a material of interest for the development of a ferroelectric RAM for computers. The inclusion of SrTiO3, an incipient ferroelectric, and the fact that the properties of a BST system depend strongly on its relative composition of BaTiO3 and SrTiO3 (ST), make also this a material of high interest. Compositionally graded systems are of further interest , partly …


Improving Oceanic Overflow Representation In Climate Models: The Gravity Current Entrainment Climate Process Team, Sonya Legg, Bruce Briegleb, Yeon Chang, Eric P. Chassignet, Gokhan Danabasoglu, Tal Ezer, Arnold L. Gordon, Stephen Griffies, Robert Hallberg, Laura Jackson, William Large, Tamay M. Ozgokmen, Hartmut Peters, Jim Price, Ulrike Riemenschneider, Wanli Wu, Xiaobiao Xu, Jiayan Yang May 2009

Improving Oceanic Overflow Representation In Climate Models: The Gravity Current Entrainment Climate Process Team, Sonya Legg, Bruce Briegleb, Yeon Chang, Eric P. Chassignet, Gokhan Danabasoglu, Tal Ezer, Arnold L. Gordon, Stephen Griffies, Robert Hallberg, Laura Jackson, William Large, Tamay M. Ozgokmen, Hartmut Peters, Jim Price, Ulrike Riemenschneider, Wanli Wu, Xiaobiao Xu, Jiayan Yang

CCPO Publications

Oceanic overflows are bottom-trapped density currents originating in semienclosed basins, such as the Nordic seas, or on continental shelves, such as the Antarctic shelf. Overflows are the source of most of the abyssal waters, and therefore play an important role in the large-scale ocean circulation, forming a component of the sinking branch of the thermohaline circulation. As they descend the continental slope, overflows mix vigorously with the surrounding oceanic waters, changing their density and transport significantly. These mixing processes occur on spatial scales well below the resolution of ocean climate models, with the result that deep waters and deep western …


Development Of An Original Laboratory Prototype For A Field Tritium Detector Containing A Pem Electrolyzer Mounted In Series With A Gas Proportional Counter, Aurelie Soreefan May 2009

Development Of An Original Laboratory Prototype For A Field Tritium Detector Containing A Pem Electrolyzer Mounted In Series With A Gas Proportional Counter, Aurelie Soreefan

All Dissertations

Tritium is naturally present in very small concentrations in the environment, principally in the form HTO. Thermonuclear detonations, leaks from waste tanks at the Department of Energy (DOE) sites and accidental releases from nuclear power plants have introduced significant quantities of tritium into the environment. Even though tritium is the least toxic of the known beta emitters, its presence in the environment, primarily in the aqueous form, poses a radiological threat because of its easy accessibility. Tritium removal from the environment is technologically impractical. Thus tritium contamination is generally contained, decays in place and is monitored to protect the public …


A Study Of Relevance Feedback In Vector Space Model, Deepthi Katta May 2009

A Study Of Relevance Feedback In Vector Space Model, Deepthi Katta

UNLV Theses, Dissertations, Professional Papers, and Capstones

Information Retrieval is the science of searching for information or documents based on information need from a huge set of documents. It has been an active field of research since early 19th century and different models of retrieval came in to existence to cater the information need.

This thesis starts with understanding some of the basic information retrieval models, followed by implementation of one of the most popular statistical retrieval model known as Vector Space Model. This model ranks the documents in the collection based on the similarity measure calculated between the query and the respective document. The user …


Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva May 2009

Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actinide mononitrides have been considered as a possible nuclear fuel for the Generation-IV nuclear reactor systems. In the process of evaluating these actinide mononitrides as nuclear fuel, it is important to study different chemical and physical characteristics of these compounds. Synthesis of the materials is thus important. Carbothermic reduction is one of the techniques that have been used to synthesize actinide mononitrides. In this method, a mixture of actinide oxide such as UO 2 and excess carbon is heat treated at temperatures greater than 1700 °C under a nitrogen atmosphere. The technique is however not promising in synthesizing the actinide …


Uncertainty, Sensitivity And Geostatistical Studies Of Flow And Contaminant Transport In Heterogeneous Unsaturated Zone, Feng Pan May 2009

Uncertainty, Sensitivity And Geostatistical Studies Of Flow And Contaminant Transport In Heterogeneous Unsaturated Zone, Feng Pan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objectives of this study are: (1) to develop a methodology of estimating probability density functions (PDFs) of unsaturated hydraulic parameters when field samples are sparse, (2) to evaluate the predictive uncertainties in flow and contaminant transport due to parameter uncertainties in the layer- and local-scale heterogeneities of hydraulic parameters in unsaturated zone (UZ), (3) to investigate the contributions of the parameter uncertainties to the flow and transport uncertainties, and (4) to estimate the spatial correlation structures of hydraulic parameters by incorporating prior information and site measurements.

At layer scale, the uncertainty assessment of flow and contaminant transport in UZ …


Turn Constrained Path Planning Problems, Victor M. Roman May 2009

Turn Constrained Path Planning Problems, Victor M. Roman

UNLV Theses, Dissertations, Professional Papers, and Capstones

We consider the problem of constructing multiple disjoint paths connecting a source point s to a target point t in a geometric graph. We require that the paths do not have any sharp turn angles. We present a review of turn constrained path planning algorithms and also algorithms for constructing disjoint paths. We then combine these techniques and present an O(nlogn) time algorithm for constructing a pair of edge disjoint turn constrained paths connecting two nodes in a planar geometric graph. We also consider the development of a turn constrained shortest path map in the presence of …


Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller May 2009

Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Springs Preserve near downtown Las Vegas, Nevada contains a seven-acre constructed wetland. Springs Preserve managers are planning to use water from the constructed wetland to irrigate creeks immediately north of the wetland. These creeks will be used by a variety ofaquatic wildlife, including endangered amphibians sensitive to harmful metalloids, such as selenium, lead, and arsenic.

In an attempt to answer toxicological questions about contaminant concentrations in the constructed wetland, three metals and metalloids (selenium, arsenic, and lead), two nutrients (nitrogen and phosphorus), and the major ionic species were analyzed at four sampling locations for aqueous concentrations, in two separate …


Generalized Probabilistic Bowling Distributions, Jennifer Lynn Hohn May 2009

Generalized Probabilistic Bowling Distributions, Jennifer Lynn Hohn

Masters Theses & Specialist Projects

Have you ever wondered if you are better than the average bowler? If so, there are a variety of ways to compute the average score of a bowling game, including methods that account for a bowler’s skill level. In this thesis, we discuss several different ways to generate bowling scores randomly. For each distribution, we give results for the expected value and standard deviation of each frame's score, the expected value of the game’s final score, and the correlation coefficient between the score of the first and second roll of a single frame. Furthermore, we shall generalize the results in …


Qualitative Behavior Of Solutions To Differential Equations In RN And In Hilbert Space, Qian Dong May 2009

Qualitative Behavior Of Solutions To Differential Equations In RN And In Hilbert Space, Qian Dong

Masters Theses & Specialist Projects

The qualitative behavior of solutions of differential equations mainly addresses the various questions arising in the study of the long run behavior of solutions. The contents of this thesis are related to three of the major problems of the qualitative theory, namely the stability, the boundedness and the periodicity of the solution. Learning the qualitative behavior of such solutions is crucial part of the theory of differential equations. It is important to know if a solution is bounded or unbounded or if a solution is stable. Moreover, the periodicity of a solution is also of great significance for practical purposes.


Arsenic And Selenium Distribution In Coal-Fired Plant Samples, Pauline Rose Hack Norris May 2009

Arsenic And Selenium Distribution In Coal-Fired Plant Samples, Pauline Rose Hack Norris

Masters Theses & Specialist Projects

Arsenic and selenium distributions in coal-fired plant samples are studied. This research includes arsenic and selenium concentrations in samples of coal, fly ash, bottom ash, economizer ash, Flue Gas Desulfurization (FGD) slurry and flue gas taken from four power plants with the goal being to examine the distribution of these metals in these materials and calculate a materials balance for the system. All samples were analyzed using ICP-ES.

This research shows that 60-80% of the arsenic in coal-fired plant samples will be associated with the fly ash. Approximately 35-55% of the selenium will be associated with the fly ash and …


Real Time Driver Safety System, Gyuchoon Cho May 2009

Real Time Driver Safety System, Gyuchoon Cho

Masters Theses & Specialist Projects

The technology for driver safety has been developed in many fields such as airbag system, Anti-lock Braking System or ABS, ultrasonic warning system, and others. Recently, some of the automobile companies have introduced a new feature of driver safety systems. This new system is to make the car slower if it finds a driver’s drowsy eyes. For instance, Toyota Motor Corporation announced that it has given its pre-crash safety system the ability to determine whether a driver’s eyes are properly open with an eye monitor. This paper is focusing on finding a driver’s drowsy eyes by using face detection technology. …


Vadose Zone Hydrology Near The Vicinity Of Edna's Dome, Mammoth Cave, Kentucky, Johnny Merideth May 2009

Vadose Zone Hydrology Near The Vicinity Of Edna's Dome, Mammoth Cave, Kentucky, Johnny Merideth

Masters Theses & Specialist Projects

This study examines the differences in key physical aqueous parameters at two different cave sites separated by only a few tens of meters. One site (FF) has a freefalling water component where water descends nearly 30 meters from the ceiling of a vertical shaft. The other location (WW) appears to have continuous water to rock contact as it descends to near the same level in the cave.

Water samples were collected at the two sites in two week intervals from May to August 2002. While both sites were proximal, they demonstrated very different behaviors, particularly during storm events. Differences in …