Physical Sciences and Mathematics Commons^™

New Topologies And Parallel Algorithms For Static Interconnection Networks., Srabani Sen Gupta Dr.

Doctoral Theses

Many real-life applications in the areas of signal processing, image processing, etc., require a large amount of fast computations to be performed. Although high speed powerful processors are currently available due to the phenomenal advances in VLSI technology, the increasing demand for massive real-time computations can not be met just by a uniprocessor system. One way of achieving the goal of fast computation is through parallel processing. In parallel processing, a problem is broken into several subproblems, which are distributed among different processors so that each of the processors can perform its task simultaneously. Main areas of recent research in …

Some Problems In Estimating Finite Population Total And Variance In Survey Sampling., Saswati Bhattacharya Dr.

Doctoral Theses

The problem of drawing inference concerning the parameters of a finite population of identifiable units has been increasingly engaging the attention of statisticians. The central problem here is to devise a suitable method of selecting a sample from the population and to employ an appropriate estimator to estimate the finite population total or mean. A consider- able progress in this field of study has been made and many authors have contributed towards the development of the theory in this aspect of the problem of statistical inferenceNumerous papers have been written covering the first aspect of the problem, namely, method of …

Concept Vectors: A Synthesis Of Concept Mapping And Matrices For Knowledge Representation In Intelligent Tutoring Systems, Mark L. Dyson

Theses and Dissertations

A review of the literature relating to intelligent tutoring systems (ITS) reveals that the bulk of research to date is focused on the student, and on methods for representing the knowledge itself. From student models to learning schemas to presentation methods, comparatively little attention has been paid to the problem of educators attempting to build viable lesson plans for use in an ITS environment--yet when this problem is addressed in the literature, it is recognized as a potentially daunting one. This thesis addresses the problem of ITS lesson plan development by proposing a practical, computable approach for knowledge engineering that …

A Palynological Study Of Two Upland Bogs In The Gulf Coastal Plain, Alabama And Mississippi, Linda C. Pace

LSU Historical Dissertations and Theses

Fewer Quaternary palynological studies have been conducted in the Gulf Coastal Plain of the southeastern United States than In the northern United States and Canada, resulting in major gaps in the pollen record of this region. The existing studies display discrepancies in the chronology of the pine rise, appearance of the modem climatic regime and vegetation, and timing of the Hypsithermal. In order to fill a gap in the paleoecological data network of the Gulf Coastal Plain, pollen analysis, charcoal analysis, and sediment stratigraphic techniques were used to reconstruct the last 6500 years of Sweetbay Bog, Mississippi, and Minamac Bog, …

The Determination Of The Crystal Structure Of 2-Methyl-2methylacrylyl-Cyclohexanone- (1,5)-Diaxaspiro Mononeopentyl By X-Ray Christallography, Joann Stevenson

McCabe Thesis Collection

Cyclohexanone, the central component of the compound 2-methyl-2-methylacrylylcyclohexanone-( l,5)-diaxaspiro mononeopentyl (see figure on page 2), serves as a solvent for oil in piston type aircraft and in natural and vinyl resins. It is used in the production of crude rubber, waxes, fats, shellac and DDT and other pesticides. Cyclohexanone also is a part of the production of adipic acid, which is used to prepare nylon and is used to prepare cyclohexanone resins via condensation to enhance the adhesive properties of products like floor paints.

Cyclohexanones are among the most accessible hydroaromatic derivatives and serve as the initial materials for the …

A Plan For Characterizing Waste For The Defense Special Weapons Agency At The Nevada Test Site, Tiffany A. Hatcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 1976, Congress adopted the Resource Conservation and Recovery Act (RCRA) to govern hazardous waste. The Act was amended in 1984 with the Hazardous and Solid Waste Amendments in order to further define the requirements of RCRA. RCRA is meant to protect human health and the environment from the effects of hazardous waste, promote waste minimization, and encourage material recycling and recovery. For this purpose, regulations are implemented that cover every aspect of the hazardous waste problem, including generation, transport, treatment, storage, and disposal.

Generators of waste are the most important part of this chain. As defined in RCRA, a …

Pan, Ppn And Mpan Measurements And The Systematic Relationship Between Mpan And Macr At A Semi-Rural Site In Tennessee, George Nouaime

Masters Theses

Simultaneous measurements of peroxymethacryloyl nitrate (MPAN) and its primary and secondary precursors, methacarolein (MACR) and isoprene, were carried out for the first time in July 1995 at a semi-rural site southeast of Nashville. In addition to these compounds, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), other volatile organic compounds (VOCs) and supporting measurements were also collected in collaboration with other research groups. The mean concentrations of PAN, PPN, MPAN and MACR were found to be 485 pptv, 50 pptv, 30 pptv and 0.290 ppbv respectively. MP AN levels, which closely tracked those of MACR during the day, peaked and dropped earlier …

Elucidation Of The Pathway Required For The Stimulation Of G6pdh Gene Expression By Insulin And Its Mimetics, Asavari Wagle

Masters Theses

Insulin, an anabolic hormone, exquisitely controls cellular physiology and metabolism by modulating the activity of key proteins which regulate metabolic and mitogenic events. Insulin activates several cytosolic proteins via a phosphorylation cascade, but only some of these proteins are required for its specific action. We have elucidated the insulin signal transduction cascade in primary rat hepatocytes, and outlined some of the events that are required for the insulin induced stimulation of glucose-6-phosphate dehydrogenase (G6PDH) gene expression. Using well-characterized and structurally different inhibitors, we show that insulin stimulation of the gene requires the IRS-1/P13K pathway and not the RAS/RAF/MAPK pathway. Gene …

A Comparison Study Of Water Well Grouting Materials, Sherry L. Callaway

Masters Theses

To prevent contamination from occurring in water wells, and thereby groundwater, the annulus between the well casing and borehole wall must be sealed with a grout that is capable of maintaining a proper seal. Several factors and properties determine the integrity of the grout and the seal formed by that grout.

A field study discovered limitations in all of the tested grout types. Most grouts were found to vary greatly in thickness surrounding the well casing. Bentonite slurry grouts settled excessively. Cement and bentoni tecement grouts did not adhere to PVC well casing. Bentonite-cement grout fractured. The granulated bentonite was …

Lithological And Stratigraphic Analysis Of Glacial Diamictons, Sturgis, Michigan, R. Christopher Gardner

Masters Theses

Seven diamictons are identified in the subsurface glacial drift near Sturgis, Michigan using textural analyses and x-ray diffraction of clay minerals. The clay mineral content is quantified by comparing the 7-A/10- A peak height ratios from x-ray diffraction diffractograms of oriented clay-size particle (<2um) mounts. Two diamictons occur at the base of the drift. Unit 1 is gray , resembling the shale it overlies. The texture of Unit 1 is sandy clay loam to loam and average 7-A/10-A peak height clay mineral ratios of 0.446 ±0.069. Unit 2 is a yellowish-brown diamicton, it overlies Unit 1, and is a sandy loam to loam with average 7-A/10-A clay mineral ratio of 0.657 ±0.151. Diamicton Units 4 and 5 overlie a thick unit of sand and gravel on top of Unit 2. Units 4 and 5 have similar color and texture, however the 7-A/10-A ratios are 1.059 ±0.090 and 0.810 ±0.072 respectively. Unit 6 is a thin diamicton unit, leached of calcite, and x-ray diffraction suggests that there is a range of weathering horzins between borings. Unit 7 is loamy, whereas Unit 8 generally ranges from sandy clay loam to sandy loam with average 7-A/10-A ratios of 0.865 ±0.090 and 1.195 ±0.189.

Collision Spectroscopy Of Low Energy Capture By Multiply Charged Ions From Atomic Targets, Kadir Akgungor

Dissertations

State-selective differential cross sections for single-electron capture processes in very slow collisions of Ar^q+ (q = 4 - 6) ions with Ne, and Ar^6+ ions with He have been studied experimentally at laboratory collision energies between 15 and 100 qeV, and at scattering angles between 0° and 8° by means of translational energy-gain spectroscopy technique. The translational energy spectra show that only a few final states are populated depending on the charge state of the projectile, the projectile laboratory scattering angle, and the collision energy. These measurements also show that the dominant reaction channels are due to capture into excited …

Laboratory Comparison Of Trench Design Options For Recovering Spilled Oil, Renuka Fernando

Masters Theses

The research goal was to improve the performance of drainage trenches used to recover spilled oil in the subsurface. Different trench designs were compared in two laboratory experiments. The first laboratory experiment clearly demonstrates that the performance of a oil recovering drainage trench could be improved by replacing the standard gravel pack sand used around the drain pipe with mixtures of teflon and sand. The effectiveness of a downgradient impermeable 'backstop' also was studied in the first experiment.

In experiment two, four trench designs were compared: perforated drain pipe; wire-wrapped horizontal well screen; perforated sheet pile; and gravel fill with …

A Large Scintillation Detector For Nuclear Physics Experiments At Indiana University Cyclotron Facility, Apurva Pathak

Masters Theses

A new, large, scintillation detector, called the "K" detector has been designed and built for use in a series of nuclear physics experiments being performed at the Indiana University Cyclotron Facility (IUCF). This project describes the design, construction and testing of this scintillation detector. The K detector was designed to augment an existing detector stack at IUCF, and will serve to increase the energy range of previous studies of neutral pion production in proton-proton collisions near threshold. The test data for the current project came from a proton-proton scattering experiment, during which several runs were carried out between the bombarding …

Vertical Axis Rotation In The Silurian Hills: A Cenozoic Overprint On The Mesozoic U.S. Cordilleran Magmatic Arc, John E. Comstock

University of New Orleans Theses and Dissertations

New, detailed field work in the Silurian hills, southeast of Death Valley, reveals a pattern of a complex Cenozoic brittle fault overprint of rocks containing evidence of at least three episodes of Mesozoic thermal-ductile deformation. The Cenozoic brittle fault overprint of rocks containing evidence of at least three episodes of Mesozoic thermal-ductile formation. The Cenozoic faulting consists of five distinct sets of structures ordered by cross cutting relationships. The oldest, BF1, are fragments of reverse faults trending NW and dipping 45-60 SW. BF2 consist of NW trending, en echelon, sinistral strike-slip faults. BF3 is a conjugate set of N-NE trending …

Inhibitory Effect Of Carbamate On The Cell Division Of Rat Bone Marrow, Mariam Hamad Rashed Al-Dhaheri

Theses

The cytotoxic effect of methomyl carbamate was studied in three groups (control group, 1 % treated group and 10% treated group) and each group contain 2-3 White Wistar rats. The 1% treated group was received 1 % of methomyl LD₅₀, while the 10% treated group was received 10% of methomyl LD₅₀. The administration was orally and repeated three times with 24 hr intervals time. The effect of methomyl was investigated in four experimental run, by analysing the change in cell count in bone marrow after methomyl treatment. It was found that methomyl treatment caused significant reduction …

Application Of Geophysical And Geochemical Techniques For The Assessment Of Groundwater Recharge From Wadi Al Bih Dams, Ras Al Khaimah, United Arab Emirates, Mohamed Sager Al Asam

Theses

Groundwater from Wadi AI Bih is still a major source of water required for irrigation, industry and domestic purposes in Ras AI Khaimah area, United Arab Emirates. Because of the continuous population growth, demand for pumping more water has created an imbalance in the groundwater resources of Wadi AI Bih basin, and the estimated discharge (11 million m³/year) has exceeded the calculated natural recharge (9 million m³/yr). To restore the balance between natural recharge and discharge and maintain a good-quality groundwater, the UAE government has built Wadi AI Bih dams in 1982.

The objectives of this …

An Investigation Of Plume Rise From Titan Iv Rocket Launches, Joseph D. Brands

Theses and Dissertations

Space launches at Cape Canaveral Air Station (CCAS) and Vandenberg Air Force Base (vAFB) produce exhaust ground clouds from the solid rocket boosters and liquid hypergolic fuels containing several toxic substances. In order to estimate the health effects that would be imposed upon the public by scheduled launches, range safety officials rely on the Rocket Exhaust Effluent Diffusion Model to predict ground level concentrations of these substances. A drawback to the REEDM is its underprediction of the initial ground clouds stabilization height. This underprediction causes an overprediction of the ground level toxic substance concentrations. This thesis focused on increasing the …

Pesticide-Related Health Problems And Illness In Farm-Workers In The United Arab Emirates, Mahra Mohammed Mahmood Beshwari

Theses

Arabian Gulf countries, witnessed rapid development in many aspects of life. Although these

developments have improved the quality of life in the UAE, they have drawbacks that generated

health problems and environmental hazards. One of the consequences of rapid development is the

usage of large amounts of pesticides in agricultural production for the sake of increasing the yield of crops. However, the expanded use of these pesticides is known to result in acute respiratory symptoms and changes in body metabolism. To-date, no population-based study has been conducted to investigate the effects of pesticides on plasma amino acids and liver enzyme …

The Rational Resolution Analysis: A Generalization Of Multi-Resolution Analyses With Application To To The Specific Emitter Identification Problem, Bruce P. Anderson

Theses and Dissertations

The rational resolution analysis RRA is introduced and developed as a generalization of the integer, dilation multiresolution analyses MRA developed by Mallat and Meyer. Rational dilation factors are achieved by relaxing the condition on MRAs that successive approximation spaces be embedded. Conditions for perfect reconstruction are discussed and it is shown that perfect reconstruction is possible with specific constraints on the scaling function the scaling filter must have its roots on the unit circle. Furthermore, the required arrangement of the roots indicate the scaling function must be derived from a B-spline of some degree. It is proven the only compactly …

An Incompleteness Handling Methodology For Validation Of Bayesian Knowledge Bases, David J. Bawcom

Theses and Dissertations

The PESKI (Probabilities, Expert Systems, Knowledge, and Inference) system attempts to address some of the problems in expert system design through the use of the Bayesian Knowledge Base (BKB) representation. Knowledge gathered from a domain expert is placed into this framework and inferencing is performed over it. However, by the nature of BKBs, not all knowledge is incorporated, i.e. the representation need not be a complete representation of all combinations and possibilities of the knowledge, as this would be impractical in many real-world systems. Therefore, inherent in such a system is the problem of incomplete knowledge, or spaces within the …

Developing A Corpus Specific Stoplist Using Quantitative Comparison, Craig N. Berg

Theses and Dissertations

We have become overwhelmed with electronic information and it seems our situation is not going to improve. It is becoming increasingly common for people to work with information on a daily basis. We seem to spend more and more time looking for information, and it is taking longer because more information is available. This thesis will look at how we can provide faster access to the information we want to find. Today's requirements are closely related to searching for information using queries. At the heart of the query process is the removal of search terms having little or no significance …

The Fate And Transport Of Airborne Jp-4 And Jp-8 Aerosol During Cold Startup, Bradford Eugene Buckman

Theses and Dissertations

During cold startup (engine warm-up) procedures at northern tier bases, fuel aerosol (JP-4 and JP-8) is emitted before complete combustion of the fuel occurs. The time necessary for complete combustion to occur may be as long as 10 minutes. Hence, during these first few minutes, aerosol is emitted at relatively high concentrations. This research investigates the principle behavior of the emitted aerosol: advection, dispersion, evaporation, and settling. Using previous work in fuel jettisoning and evaporation as a foundation, this thesis investigates the physical factors affecting the airborne concentration of fuel aerosol at different times, the amount of fuel aerosol reaching …

Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush

Theses and Dissertations

Existing missile/target encounter modeling and simulation systems focus on improving probability of kill models. Little research has been done to visualize these encounters. These systems can be made more useful to the engineers by incorporating current computer graphics technology for visualizing and animating the encounter. Our research has been to develop a graphical simulation package for visualizing both endgame and full fly-out encounters. Endgame visualization includes showing the interaction of a missile, its fuze cone proximity sensors, and its target during the final fraction of a second of the missile/target encounter. Additionally, this system displays dynamic effects such as the …

A System Dynamics Model Of The Bioavailability Of Metals In Constructed Wetland Sediment, Timothy S. Wood

Theses and Dissertations

Constructed wetlands used for storm water treatment accumulate metals primarily in their sediment. This sediment has the potential to produce toxic effects in benthic organisms at some period in time. Bioavailability of metals in sediment is directly linked to pore water metal activity. The mechanisms that influence pore water metal activity are included in physical, chemical, and biological processes. A system dynamics model was developed to represent these processes and the major influences affecting pore water metal activity in a treatment wetland receiving storm water influent. The model structure and behavior was tested and validated using several system dynamics validation …

Reactive Quantum Scattering In Two Dimensions, Roy S. Calfas

Theses and Dissertations

In an effort to develop a more efficient time dependent approach for calculating scattering matrix elements, absorbing boundary conditions are combined together with the channel packet method. As an introduction to scattering, scattering matrix elements are presented for a one-dimensional square well and a one-dimensional potential consisting of a Gaussian well with symmetric Gaussian barriers. Next, the combination of the channel packet method together with absorbing boundary conditions yields an order of magnitude savings in the time necessary to compute the correlation function for the collinear H+H

Spontaneous Emission In Microcavity Lasers, Dustin Philip Ziegler

Theses and Dissertations

An understanding of spontaneous emission processes within microcavities is crucial in addressing the need to make tomorrow's microlasers more efficient. One approach to improving the device efficiency is to reduce the threshold input energy at which lasing begins to occur. It has been suggested that the threshold in a microcavity laser can be decreased by increasing the fraction of spontaneous emission into the lasing mode, this can be accomplished by preferentially coupling the gain medium of the laser to the electromagnetic cavity mode of interest. It therefore becomes necessary to understand the mechanism by which this coupling takes place. This …

Mobilization Of Trace Elements In Aquifers By Biodegradation Of Hydrocarbon Contaminants, Scott L. Kearney

Theses and Dissertations

This study had two objectives: (1) to determine the extent of metal mobility within petroleum-contaminated aquifers, (2) to determine if biodegradation of petroleum hydrocarbons can explain metal mobility. The approach reviewed analytical results from 2305 groundwater sampling events, taken from 958 wells, located at 136 sites found at 53 Air Force installations. The study showed that high levels of metals are present at petroleum hydrocarbon sites where metals would not generally be expected. Of the metals with drinking water maximum contaminant levels (MCLs), mercury and silver were detected the least frequently. Barium and copper were detected at the sites, but …

Requirements, Design And Prototype Of A Virtual User Interface For The Afit Virtual Spaceplane, John M. Lewis

Theses and Dissertations

The United States Air Force is evaluating the feasibility of designing a military spaceplane capable of accomplishing military objectives from a low earth orbit and atmospheric flight regimes. Current efforts are involved in determining the scientific, operational, and budgetary constraints associated with this concept. This thesis looks at the exploration of new interface techniques associated with the design of a virtual spaceplane and is a subset of the overall virtual spaceplane effort which will assist researchers in determining the feasibility of a military spaceplane. Interface techniques are integrated into a virtual user interface that is designed to accommodate expected operations …

An Examination Of Multi-Tier Designs For Legacy Data Access, Michael L. Acker

Theses and Dissertations

This work examines the application of Java and the Common Object Request Broker Architecture (CORBA) to support access to remote databases via the Internet. The research applies these software technologies to assist an Air Force distance learning provider in improving the capabilities of its World Wide Web-based correspondence system. An analysis of the distance learning provider's operation revealed a strong dependency on a non-collocated legacy relational database. This dependency limits the distance learning provider's future web-based capabilities. A recommendation to improve operation by data replication is proposed, and the implementation details are provided for two alternative test systems that support …

Pseudorandom Code Generation For Communication And Navigation System Applications, John F. Brendle Jr.

Theses and Dissertations

This research project investigated the design, construction and evaluation of a pseudorandom code generator for communication and navigation system applications. These types of codes include spreading codes, Gold codes, Jet Propulsion Laboratory (JPL) ranging codes, syncopated codes, and nonlinear codes. Such waveforms are typically used in communication and navigation system applications. The code generator uses the Stanford Telecom STEL-1032 Pseudorandom Number (PRN) coder. A coder interface was designed and constructed for manual data entry to the registers of the PRN coder. The code generator is capable of independently clocking and generating all possible codes with lengths up to 4,294,967,295 bits. …