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Articles 1 - 30 of 39
Full-Text Articles in Physical Sciences and Mathematics
A Probability Programming Language: Development And Applications, Andrew Gordon Glen
A Probability Programming Language: Development And Applications, Andrew Gordon Glen
Dissertations, Theses, and Masters Projects
A probability programming language is developed and presented; applications illustrate its use. Algorithms and generalized theorems used in probability are encapsulated into a programming environment with the computer algebra system Maple to provide the applied community with automated probability capabilities. Algorithms of procedures are presented and explained, including detailed presentations on three of the most significant procedures. Applications that encompass a wide range of applied topics including goodness-of-fit testing, probabilistic modeling, central limit theorem augmentation, generation of mathematical resources, and estimation are presented.
Improvements To The Color Quantization Process, Rance David Necaise
Improvements To The Color Quantization Process, Rance David Necaise
Dissertations, Theses, and Masters Projects
The presentation of color images on devices with limited color capabilities requires a reduction in the number of colors contained in the images. Color image quantization is the process of reducing the number of colors used in an image while maintaining its appearance as much as possible. This reduction is performed using a color image quantization algorithm. The quantization algorithm attempts to select k colors that best represent the contents of the image. The original image is then recolored using the representative colors. to improve the resulting image, a dithering process can be used in place of the recoloring.;This dissertation …
Exploiting Cache Locality At Run-Time, Yong Yan
Exploiting Cache Locality At Run-Time, Yong Yan
Dissertations, Theses, and Masters Projects
With the increasing gap between the speeds of the processor and memory system, memory access has become a major performance bottleneck in modern computer systems. Recently, Symmetric Multi-Processor (SMP) systems have emerged as a major class of high-performance platforms. Improving the memory performance of Parallel applications with dynamic memory-access patterns on Symmetric Multi-Processors (SMP) is a hard problem. The solution to this problem is critical to the successful use of the SMP systems because dynamic memory-access patterns occur in many real-world applications. This dissertation is aimed at solving this problem.;Based on a rigorous analysis of cache-locality optimization, we propose a …
Platinized Tin Oxide: A Low-Temperature Oxidation Catalyst, Erik Joshua Kielin
Platinized Tin Oxide: A Low-Temperature Oxidation Catalyst, Erik Joshua Kielin
Dissertations, Theses, and Masters Projects
Some combinations of noble metal and reducible metal oxide possess a synergistic level of activity for the catalytic oxidation of CO at lower temperatures and partial pressures of O2 than can be obtained by either component alone. The most promising candidates, Au on MnO2 and Pt on SnO 2, were investigated for the effects on activity of noble metal loading, of reductive pretreatment at elevated temperature, and of reaction gas mixture composition. Optimum activity was obtained at a noble metal loading of 28% Au/MnO2 and 17% Pt/SnO2. Both catalysts benefitted from reductive CO pretreatment at 125??C. Both catalysts showed enhanced …
Oyster Reef Broodstock Enhancement In The Great Wicomico River, Virginia, Melissa Southworth
Oyster Reef Broodstock Enhancement In The Great Wicomico River, Virginia, Melissa Southworth
Dissertations, Theses, and Masters Projects
No abstract provided.
The Effect Of Phragmites Australis Invasion On Community Processes In A Tidal Freshwater Marsh, Michael Leadbeater Campana
The Effect Of Phragmites Australis Invasion On Community Processes In A Tidal Freshwater Marsh, Michael Leadbeater Campana
Dissertations, Theses, and Masters Projects
No abstract provided.
First Observation Of The Very Rare Decay Neutral Kaon(Long) Going To Electron Positron, Robert David Martin Iii
First Observation Of The Very Rare Decay Neutral Kaon(Long) Going To Electron Positron, Robert David Martin Iii
Dissertations, Theses, and Masters Projects
Brookhaven National Laboratory AGS Experiment 871 (E871) has carried out a search for the very rare, GIM and helicity suppressed decay of the long-lived neutral kaon into an electron-positron pair. This decay is predicted within the Standard Model to occur with a branching ratio of {dollar}(9.0 \pm 0.4)\times 10\sp{lcub}-12{rcub}.{dollar} Data were taken during the 1995 and 1996 AGS HEP running periods on the B5 beamline. A signal of (4 {dollar}\pm{dollar} 2) {dollar}K\sbsp{lcub}L{rcub}{lcub}0{rcub} \to e\sp+e\sp-{dollar} events is seen with a physics background expectation of 0.2 events. The ratio of the partial decay widths {dollar}\Gamma(K\sbsp{lcub}L{rcub}{lcub}0{rcub} \to e\sp+e\sp-)/\Gamma(K\sbsp{lcub}L{rcub}{lcub}0{rcub}\to\mu\sp+\mu\sp-){dollar} is determined to be {dollar}(1.3\sbsp{lcub}-0.6{rcub}{lcub}+0.8{rcub} …
Physical Parameters Affecting Incubating Temperatures In Loggerhead Sea Turtles, Caretta Caretta, In Virginia, William Mason Jones
Physical Parameters Affecting Incubating Temperatures In Loggerhead Sea Turtles, Caretta Caretta, In Virginia, William Mason Jones
Dissertations, Theses, and Masters Projects
Detailed physical profile of eight transplanted loggerhead sea turtle, Caretta caretta, nests were obtained from Virginia and northeastern North Carolina and reburied in Back Bay National Wildlife Refuge (BBNWR), Virginia Beach, Virginia during the summers of 1987, '88, and '89 to determine if the physical location of the egg within the nest had an affect on sex determination. Transplanted nests were reburied in sandy substrate at a depth of 15-60 em on south facing dunes, and a Campbell Scientific data-logger logged synchronously environmental data. The following data were collected: temperatures at various locations within a nest, net absorbed radiation, ambient …
Tidal Freshwater And Oligohaline Benthos: Evaluating The Development Of A Benthic Index Of Biological Integrity For Chesapeake Bay, Robyn C. Draheim
Tidal Freshwater And Oligohaline Benthos: Evaluating The Development Of A Benthic Index Of Biological Integrity For Chesapeake Bay, Robyn C. Draheim
Dissertations, Theses, and Masters Projects
No abstract provided.
Tagging And Habitat Utilization Of Juvenile Summer Flounder, Paralichthys Dentatus, Richard Thomas Kraus
Tagging And Habitat Utilization Of Juvenile Summer Flounder, Paralichthys Dentatus, Richard Thomas Kraus
Dissertations, Theses, and Masters Projects
No abstract provided.
Distribution, Partitioning And Fluxes Of Dissolved And Particulate Organic Carbon, Nitrogen And Phosphorus In The Eastern North Pacific And Southern Oceans, Ai Ning Loh
Dissertations, Theses, and Masters Projects
No abstract provided.
Development Of A Quantitative Competetive Polymerase Chain Reaction Assay For The Detection And Quantitation Of Perkinsus Marinus In Oyster Tissues And Environmental Water Samples, Heather A. Yarnall
Development Of A Quantitative Competetive Polymerase Chain Reaction Assay For The Detection And Quantitation Of Perkinsus Marinus In Oyster Tissues And Environmental Water Samples, Heather A. Yarnall
Dissertations, Theses, and Masters Projects
No abstract provided.
A Search For Lepton Flavor Violation In The Neutral Kaon System, Christopher Henry Hoff
A Search For Lepton Flavor Violation In The Neutral Kaon System, Christopher Henry Hoff
Dissertations, Theses, and Masters Projects
The conservation of separate lepton number is an ad hoc conservation principle in the Standard Model but several non-Standard Model theories allow violation of separate lepton number conservation. A very sensitive search for lepton flavor violation in the neutral kaon system, via the decay K0L→me , was undertaken by Brookhaven National Laboratory Experiment 871 (E871) during the 1995 and 1996 AGS HEP running periods. No K0L→me decays were observed and a single event sensitivity (SES) of 1.97x10-12 was achieved. This single event sensitivity corresponds to an upper limit on the branching fraction of BK0L→m e<4.53+/-0.21+/-0.46x 10-12 at a 90% confidence level.
Analysis Of Algorithms For Online Routing And Scheduling In Networks, Jessen Tait Havill
Analysis Of Algorithms For Online Routing And Scheduling In Networks, Jessen Tait Havill
Dissertations, Theses, and Masters Projects
We study situations in which an algorithm must make decisions about how to best route and schedule data transfer requests in a communication network before each transfer leaves its source. For some situations, such as those requiring quality of service guarantees, this is essential. For other situations, doing work in advance can simplify decisions in transit and increase the speed of the network. In order to reflect realistic scenarios, we require that our algorithms be online, or make their decisions without knowing future requests. We measure the efficiency of an online algorithm by its competitive ratio, which is the maximum …
Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford
Dissertations, Theses, and Masters Projects
Phylogenetic and historical biogeographic hypotheses were explored for three groups of teleost fishes that are hypothesized to share a common biogeographic track. Distributed across the eastern Pacific/eastern Atlantic (EP/EA) biogeographic track of Rosen (1975) are the Scomberomorus regalis (Scombridae), Strongylura marina (Belonidae) and Hyporhamphus unifasciatus (Hemiramphidae) species groups comprised of one eastern Atlantic; three, three and four western Atlantic; and two, two and four eastern Pacific species, respectively, for each group. In addition, two species in the Strongylura marina and Hyporhamphus unifasciatus groups, have invaded freshwater drainages of Central and South America. Each of the three species groups were found …
Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi
Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi
Dissertations, Theses, and Masters Projects
Blue marlin diversity was assessed at mtDNA, scnDNA, microsatellite DNA, and allozyme molecular markers. Hierarchical analysis of molecular variance (AMOVA) revealed that most genetic variation was maintained within populations, with a non-significant fraction attributable to variation among temporal replicates and between locations within oceans. In contrast, inter-ocean divergence was highly significant for a majority of loci within each marker class. Previous studies of mitochondrial DNA (mtDNA; n = 104) genetic variation within the blue marlin revealed two distinct clades of haplotypes, one of which was present only in the Atlantic (the 'Atlantic clade'), at a frequency of 40% &(F\sb{lcub}st{rcub}& = …
Stability Of Quark-Antiquark Models Of Mesons: A Study On The Validity Of The Spectator, Dirac, And Salpeter Equations, Michael Uzzo
Stability Of Quark-Antiquark Models Of Mesons: A Study On The Validity Of The Spectator, Dirac, And Salpeter Equations, Michael Uzzo
Dissertations, Theses, and Masters Projects
Mesons are made of quark-antiquark pairs held together by the strong force. The one channel spectator, Dirac, and Salpeter equations can each be used to model this pairing. We look at cases where the relativistic kernel of these equations corresponds to a linear combination of scalar exchange and vector exchange. The vector exchange will be either the time-like component or the full four vector. The systems covered here are referred to as quasirelativistic, which means retardation, regularization, and form factors are not included. Since the model used in this paper describes mesons which cannot decay physically, the equations must describe …
The Role Of Adsorbed Oxygen In Secondary Emission From Metallic Substrates, Scott Gregory Walton
The Role Of Adsorbed Oxygen In Secondary Emission From Metallic Substrates, Scott Gregory Walton
Dissertations, Theses, and Masters Projects
Low energy, ion- and photon-induced secondary electron and anion emission from metallic substrates has been investigated as a function of adsorbate coverage. Sodium positive ions (Na+), with kinetic energies up to 500 eV, and photons, with energies up to 23 eV, are utilized to initiate secondary emission. The principal adsorbate is oxygen with coverages ranging from none to a few monolayers.;For ion-induced emission, the secondary electron and negative ion absolute and relative yields from 302 stainless steel and polycrystalline tungsten (W) have been measured as a function of both impact energy and oxygen coverage. Additionally, the yields from a "technical" …
Development And Analysis Of A Nutrient Trading Program For The James River Watershed, Jennifer M. Reid
Development And Analysis Of A Nutrient Trading Program For The James River Watershed, Jennifer M. Reid
Dissertations, Theses, and Masters Projects
No abstract provided.
Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers
Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers
Dissertations, Theses, and Masters Projects
No abstract provided.
Electroproduction Of The S(11)Meson(1535) Resonance At High Momentum Transfer, Christopher Stephen Armstrong
Electroproduction Of The S(11)Meson(1535) Resonance At High Momentum Transfer, Christopher Stephen Armstrong
Dissertations, Theses, and Masters Projects
The amplitude of the $S\sb{11}$(1535) resonance at values of four-momentum transfer $Q\sp2 > 0$ is not explained by the nonrelativistic constituent quark model, and is currently a topic of theoretical interest; in addition, the large branching fraction of this resonance to the proton-$\eta$ decay channel is not well understood. There is also controversy concerning the $Q\sp2$ regime in which perturbative QCD becomes important in describing nucleon resonances such as the $S\sb{11}$. The $p(e, e\sp\prime p)\eta$ reaction is an excellent system in which to study this resonance and address the issue of possible perturbative effects: the $p\eta$ channel is not accessible to …
Wavelet-Based Digital Image Restoration, Viviana Sandor
Wavelet-Based Digital Image Restoration, Viviana Sandor
Dissertations, Theses, and Masters Projects
Digital image restoration is a fundamental image processing problem with underlying physical motivations. A digital imaging system is unable to generate a continuum of ideal pointwise measurements of the input scene. Instead, the acquired digital image is an array of measured values. Generally, algorithms can be developed to remove a significant part of the error associated with these measure image values provided a proper model of the image acquisition system is used as the basis for the algorithm development. The continuous/discrete/continuous (C/D/C) model has proven to be a better alternative compared to the relatively incomplete image acquisition models commonly used …
Africa As A Regional And Global Source Of Atmospheric Gases And Particulates, Lawrence Mtetwa
Africa As A Regional And Global Source Of Atmospheric Gases And Particulates, Lawrence Mtetwa
Dissertations, Theses, and Masters Projects
The role of the continent of Africa as a source of gaseous and particulate emissions to the atmosphere is investigated in this study. Sources of gases and particulates from Africa include fossil fuel combustion, biomass burning, and biogenic soil emissions of nitric oxide. This study represents the first comprehensive database of gaseous and particulate emissions developed for the continent of Africa on a country by country basis and establishes the framework for country-by-country, assessment of greenhouse gases emissions as required by the Kyoto Conference on Global Warming, which was attended by representatives from more than 100 countries. Calculations of gases …
Coherent Neutral Pion Photoproduction On The Deuteron, David G. Meekins
Coherent Neutral Pion Photoproduction On The Deuteron, David G. Meekins
Dissertations, Theses, and Masters Projects
The differential scattering cross section for the process gd→dp0 was measured, as part of experiment E89-012 at Thomas Jefferson National Accelerator Facility. The experiment was performed in Hall C during the Spring of 1996 as the commissioning experiment for the Hall C cryogenic target. The High Momentum Spectrometer was used to detect the recoil deuteron and no effort was made to detect the p0 or its decay photons. The differential cross section was measured at a number of incident photon energies between 0.8 GeV and 4.0 GeV for the deuteron center-of-mass angles of 90?? and 136??. The data were found …
The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins
The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins
Dissertations, Theses, and Masters Projects
No abstract provided.
Searches For Exotic Matter, David Lee Morgan
Searches For Exotic Matter, David Lee Morgan
Dissertations, Theses, and Masters Projects
This research encompasses two quite distinct searches for exotic matter. The first half concerns exotic matter on the scale of elementary particles. In this chapter, I consider the production of gluinos, the supersymmetric partner of the gluon, in models where the gluino is very light. Cross sections are calculated for electroproduction and hadroproduction of gluinos and the results indicate that existing accelerators are capable of probing the region of gluino masses between 1.0 and 2.0GeV with lifetimes between 10{dollar}\sp{lcub}-10{rcub}{dollar} and 10{dollar}\sp{lcub}-6{rcub}{dollar} seconds. Such experiments could find a light gluino if it exists, or to close this unexplored mass-lifetime window. The …
Caribbean Spiny Lobster And Their Molluscan Prey: Are Top-Down Forces Key In Structuring Prey Assemblages In A Florida Bay Seagrass System, Martha Nizinski
Caribbean Spiny Lobster And Their Molluscan Prey: Are Top-Down Forces Key In Structuring Prey Assemblages In A Florida Bay Seagrass System, Martha Nizinski
Dissertations, Theses, and Masters Projects
Relative importance of predator-prey dynamics and several environmental variables in structuring gastropod and bivalve diversity and distribution was investigated in the subtropical seagrass and macroalgal community of Florida Bay, a highly productive system and primary nursery and foraging ground for finfish and invertebrate predators, including the numerically dominant Caribbean spiny lobster, Panulirus argus. The molluscan assemblage, a primary food source for P. argus in particular, is speciose (75 gastropod and 25 bivalve species) and a significant component of epifaunal and infaunal invertebrate assemblages within Florida Bay. Two experimental areas, located within separate basins and each comprised of two experimental sites, …
Interactive Effects Of Cadmium And Benzo(A)Pyrene In Mummichog (Fundulus Heteroclitus), Peter Van Den Hurk
Interactive Effects Of Cadmium And Benzo(A)Pyrene In Mummichog (Fundulus Heteroclitus), Peter Van Den Hurk
Dissertations, Theses, and Masters Projects
When animals are exposed to mixtures of environmental pollutants, it is generally assumed that the toxic effects of the individual components are additive. However, examples of synergistic and antagonistic effects have been described. to study the mechanisms of interaction between a metal and a polycyclic aromatic hydrocarbon, mummichog (Fundulus heteroclitus) were injected with combinations of cadmium (Cd) and benzo (a) pyrene (BP). Measured effect parameters were: mortality, BP-metabolite production in isolated hepatocytes and microsomes, hepatic induction of CYP1A (the BP metabolizing enzyme) and metallothionein (the Cd binding protein), and biliary excretion of BP-metabolites. The mortality data demonstrated that both synergistic …
Vertebral Cartilage Of The Clearnose Skate, Raja Eglanteria: Development, Structure, Ageing, And Hormonal Regulation Of Growth, James J. Gelsleichter
Vertebral Cartilage Of The Clearnose Skate, Raja Eglanteria: Development, Structure, Ageing, And Hormonal Regulation Of Growth, James J. Gelsleichter
Dissertations, Theses, and Masters Projects
Incremental marks formed in the vertebral cartilage of most sharks, skates and rays are widely used as indicators of age in elasmobranch growth studies. Such information is essential for fisheries management, thus vertebral ageing has become an invaluable tool for investigating elasmobranch life history. Unfortunately, lack of information on the processes that regulate vertebral growth and mineralization limit efforts to correlate episodic stimuli with increment production. to address this research need, this dissertation investigated these processes through a detailed study on the vertebral cartilage of the clearnose skate, Raja eglanteria. Histologic observations indicated that changes in appositional cartilage growth are …
A Study Of 3-Tropylium-1,5-Hexadiene, Elise Noma Hattersley
A Study Of 3-Tropylium-1,5-Hexadiene, Elise Noma Hattersley
Dissertations, Theses, and Masters Projects
No abstract provided.