Physical Sciences and Mathematics Commons^™

The Simulation, Modeling And Analysis Of Wireless Local Area Networks Supporting The Ieee 802.11 Standard, Jaikwan Joo

Theses and Dissertations

Research to improve the performance of the IEEE 802.11 has been ongoing since 1990. The focus of this research has investigated the use of the MAC and Physical layers for improving throughput. An adaptive MAC protocol, CATER (Code Adapts To Enhance Reliability) is based on the proposed MAC standard for wireless local area networks (WLAN)-802. 11. IEEE 802.11 uses a fixed Pseudo-Noise (PN) code for spreading the information signal, implying a fixed process gain at the receiver. When the channel degrades, IEEE 802.11 offers only retransmissions at the MAC layer to contend with the corrupted medium. However, CATER allows communicating …

A Web-Based Prototype For Afit Edplan Administration, Tien-Chen Lee

Theses and Dissertations

This document details the design, development, and evaluation of a prototype course registration and reporting system for the students and faculty of the United States Air Force Institute of Technology. The web-based system provides HTML-based client interfaces and Active Server Page server processes for interaction with the relational databases used to manage course and personnel data. The system prototype was developed following the "Engineering Software Components for Web-Database Access" methodology of Dipiro. A survey of modern web-based database access techniques is first provided and Dipiro's methodology is reviewed as background. The remainder of the document details the application of the …

Collisional Effects In The Absorption Spectra Of The Oxygen A Band And Nitric Oxide Fundamental Band, Robert S. Pope

Theses and Dissertations

Fourier transform spectroscopy was used to measure pressure broadening coefficients in the absorption spectra of both the oxygen A band and the nitric oxide fundamental band. Oxygen spectra were recorded with O₂, N₂, CO, CO₂, SF₆ and noble gas collision partners, while nitric oxide spectra were recorded using noble gas collision partners. Pressure broadening coefficients were determined in the P and R branches for every resolved line for each of the fifteen collision pairs studied. In addition, broadening coefficients and qualitative evidence of line coupling were found for the Q branch of NO …

Three-Dimensional Calculation Of Contaminant Transport In Groundwater At A Dover Afb Site, Tariq O. Hashim

Theses and Dissertations

Macroscale rate-limited sorption modeling was tested using a production transport code, the GMS/FEMWATER ground-water modeling package. The code (Version 1.1 of FEMWATER. dated 1 August 1995) was applied to a 3D conceptual model developed from a field site at Dover AFB, DE. A simulation was performed of a 200 hour contaminant injection pulse followed by clean water flushing. A moment analysis performed on the resulting breakthrough curve validated code self-consistency. Another injection pulse simulation showed that retardation temporally delays the breakthrough peak. Transport simulations of pulsed clean water pumping of the test cell with a prescribed initial contaminant distribution demonstrated …

Development Of An Operations Research Software Package For Army Divisions, Blane C. Wilson

Theses and Dissertations

There exists great potential for applying operations research techniques to solve specific problems in the areas of operations, installation support, and training at the Army division level. Because of the operational tempo of today's active-duty and reserve component units, command must focus on accomplishing the daily missions. Also, due their limited knowledge of the field, planners may not be aware of how operations research can be used to enhance planning and operations. Time, training funds, resources, safety, personnel, and equipment are all critical factors in this process. Operations research techniques could be used to improve division-level operations by saving time, …

Full Issue, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Factors Affecting The Movements Of Rainbow Trout (Oncorhynchus Mykiss) In Lake Ogallala, Nebraska, Tadd M. Barrow

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Cluster Versus Field Elliptical Galaxies And Clues On Their Formation, Mariangela Bernardi, Alvio Renzini, Luiz N. Da Costa, Gary Wegner

Dartmouth Scholarship

Using new observations for a sample of 931 early-type galaxies, we investigate whether the Mg₂-σ₀ relation shows any dependence on the local environment. The galaxies have been assigned to three different environments depending on the local overdensity (clusters, groups, and field); we used our complete redshift database to guide the assignment of galaxies. It is found that cluster, group, and field early-type galaxies follow almost identical Mg₂-σ₀ relations, with the largest Mg₂ zero-point difference (clusters minus field) being only 0.007±0.002 mag. No correlation of the residuals is found with the morphological type or …

The Motions Of Clusters Of Galaxies And The Dipoles Of The Peculiar Velocity Field, Riccardo Giovanelli, Martha P. Haynes, John J. Salzer, Gary Wegner

Dartmouth Scholarship

In preceding papers of this series, TF relations for galaxies in 24 clusters with radial velocities between 1000 and 9200 km s^-1 (SCI sample) were obtained, a Tully-Fisher (TF) template relation was constructed, and mean offsets of each cluster with respect to the template were obtained. Here, an estimate of the line-of-sight peculiar velocities of the clusters and their associated errors are given. It is found that cluster peculiar velocities in the cosmic microwave background reference frame do not exceed 600 km s^-1 and that their distribution has a line-of-sight dispersion of 300 km s^-1, suggesting …

Investigation Of Peptide-Dna Interactions: Synthesis, Characterization And Applications Of Lysyl-Fluorophenylalaninamides, Teresita T. Ortega

Seton Hall University Dissertations and Theses (ETDs)

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Pastoral Resources And Their Management In The Sandstone-Yalgoo-Paynes Find Area, Western Australia, A M E Van Vreeswyk, P. T. Godden

Agriculture reports

This report covers about 94,700 square kilometres of rangelands in the Sandstone-Yalgoo-Paynes Find area of Western Australia. The area lies within 27°S and 30°S latitudes, and 115°30'E and 120°E longitudes and includes the towns of Sandstone, Yalgoo and Paynes Find. The northern, southern, and eastern limits of the survey area are largely defined by the boundaries of the 1:250,000 scale series map sheets.The western limit is the boundary between the pastoral and agricultural area.

Translational Shape Invariance And The Inherent Potential Algebra, Asim Gangopadhyaya, Jeffrey Mallow, Uday P. Sukhatne

Physics: Faculty Publications and Other Works

For all quantum-mechanical potentials that are known to be exactly solvable, there are two different, and seemingly independent methods of solution. The first approach is the potential algebra of symmetry groups; the second is supersymmetric quantum mechanics, applied to shape-invariant potentials, which comprise the set of known exactly solvable potentials. Using the underlying algebraic structures of Natanzon potentials, of which the translational shape-invariant potentials are a special subset, we demonstrate the equivalence of the two methods of solution. In addition, we show that, while the algebra for the general Natanzon potential is so(2,2), the subgroup so(2,1) suffices for the shape …

Development Of Chronoamperometric Logarithmic Signatures With Application To Drug-Package Interactions And Mechanism Elucidation, Beth Sarsfield

Seton Hall University Dissertations and Theses (ETDs)

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Uncertainty In Recharge From Subsidence Craters At Frenchman Flat, Nevada Test Site: Impacts Of Initial And Boundary Conditions And Media Properties, David Matthew Ely

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada Test Site has over 400 subsidence craters formed by the collapse of overlying rock following underground nuclear tests. Under natural conditions, infiltration and recharge would not be considered likely due to infrequent precipitation events and extreme evapotranspiration. Crater U5a in Frenchman Flat was chosen for study because it intercepts significantly more drainage than surrounding craters. Vadose zone modeling was conducted to test the sensitivity of water movement to boundary and initial conditions. The effects of ponding depth was negligible but depth of wetting front movement was highly dependent on the lateral extent of the ponds. The model was …

1998 Preliminary Snowmobile Emission Survey In Yellowstone National Park, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Production Of Bound Μ⁺Μˉ Systems In Relativistic Heavy Ion Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Savely Karshenboim, Frank Krauss, Valery G. Serbo, Gerhard Soff

Physics Faculty Research & Creative Works

Dimuonium (the bound system of two muons, the μ⁺ μ^--atom system) has not been observed yet. In this paper we discuss the electromagnetic production of dimuonium at RHIC and LHC in relativistic heavy ion collisions. The production of parastates is analyzed in the equivalent photon approximation. For the treatment of orthostates, we develop a three-photon formalism. We determine the production rates at RHIC and LHC with an accuracy of a few percent and discuss problems related to the observation of dimuonium.

Nonanalytic Magnetization Dependence Of The Magnon Effective Mass In Itinerant Quantum Ferromagnets, Dietrich Belitz, Theodore R. Kirkpatrick, Andrew J. Millis, Thomas Vojta

Physics Faculty Research & Creative Works

The spin-wave dispersion relation in both clean and disordered itinerant quantum ferromagnets is calculated. It is found that effects akin to weak-localization physics cause the frequency of the spin waves to be a nonanalytic function of the magnetization m. For low frequencies Ω, small wave vectors k, and m→0, the dispersion relation is found to be of the form Ω=const x m^1-αk², with α = (4-d)/2 (2 < d < 4) for disordered systems, and α = (3-d) (1 < d < 3) for clean ones. In d = 4 (disordered) and d = 3 (clean), Ωαm ln (1/m) k². Experiments to test these predictions are proposed.

Differences Between Regular And Random Order Of Updates In Damage-Spreading Simulations, Thomas Vojta, Michael Schreiber

Physics Faculty Research & Creative Works

We investigate the spreading of damage in the three-dimensional Ising model by means of large-scale Monte Carlo simulations. Within the Glauber dynamics we use different rules for the order in which the sites are updated. We find that the stationary damage values and the spreading temperature are different for different update order. In particular, random update order leads to larger damage and a lower spreading temperature than regular order. Consequently, damage spreading in the Ising model is nonuniversal not only with respect to different update algorithms (e.g., Glauber vs heat-bath dynamics) as already known, but even with respect to the …

Charge Exchange From D(N = 2) Atoms To Low-Z Receiver Ions, R. Hoekstra, H. Anderson, F. W. Bliek, M. Von Hellermann, C. F. Maggi, Ronald E. Olson, H. P. Summers

Physics Faculty Research & Creative Works

To elucidate the influence on charge-exchange spectroscopy of metastable deuterium donors, the corresponding cross sections for state-selective charge transfer have been calculated using the classical trajectory Monte Carlo method. The cross sections for electron capture from D(n = 2) by fully stripped low-Z ions are contrasted with those for capture from ground state D to indicate the importance of metastable donors. Using the new data, effective emission coefficients for the spectral lines of H-like light impurities used in charge-exchange spectroscopy have been calculated. These results incorporate the presence of excited n = 2 donors in the beam and apply to …

Analysis Of Doubly Excited State Resonances Below The Li(5p) Threshold In Li- Photodetachment, Chien-Nan Liu, Anthony F. Starace

Anthony F. Starace Publications

Larger scale eigenchannel R-matrix calculations than those of Pan et al.  [Phys. Rev. A53, 840 (1996)] confirm the prediction of a 2-meV-wide resonance feature at a photon energy of 5.421 eV in the Li (3s) partial cross section resulting from photodetachment of Li^-. This resonance was neither clearly observed nor identified in measurements of Ljungblad et al. [Phys. Rev. Lett. 77, 3751 (1996)]. We identify this resonance as a _N{υ}_n^A=₅{1}₆^- state [having angular symmetry (K,T)^A=(2,0) ^- or (n …

Tuple Source Relational Model: A Source-Aware Data Model For Multidatabases, Ee Peng Lim, Roger Hsiang-Li Chiang, Yinyan Cao

Research Collection School Of Computing and Information Systems

In some integration projects, complete integration of database instances may not be necessary. It may also be too costly and impossible to do so due to poor local data quality and insufficient instance-level knowledge. In this research, we study how multidatabases with global schemas should be represented and manipulated when the data instances from the local databases do not require to be fully integrated. We propose the tuple source (TS) relational model to represent multidatabases under such an integration requirement. This model extends the classical relational model by augmenting every relation with a source attribute to identify the local database …

Xcert Software, Inc., Keng Siau

Research Collection School Of Computing and Information Systems

The case on Xcert Software, Inc., illustrates the operational and strategic issues encountered by a startup IT company in the Internet security business. Xcert faces difficulty in a number of areas: (1) finances, (2) future direction and leadership, (3) organizational structure, experience and size, and (4) marketing. This is a discussion case that introduces students to the competitive world of Internet business and provides them an opportunity to discuss and debate the myriad issues facing the founders of Xcert.

Methodology And Theory Building In Mis Research, Nancy Lightner, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

This paper reports on the stage of maturity of MIS research according to the McGrath (1979) model, as evidenced by the theory building occurring in two top MIS research journals. While MIS as a discipline continues to grow, its development depends on establishing a cumulative tradition of good research (Keen 1980). Of the published papers surveyed that are relevant to theory building, 81% of them relate to theory development, while 18% address theory testing. Of the papers involving data collection, more than half use field studies as the methodology. In order to advance MIS as a mature field, it is …

Measurement Of Triple Gauge Wwγ Couplings At Lep2 Using Photonic Events, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A study of events with photons and missing energy has been performed with the data sample obtained with the ALEPH detector at centre-of-mass energies from 161 to 184 GeV, corresponding to a total integrated luminosity of about 80 pb−1. The measured distributions are in agreement with Standard Model predictions, leading to constraints on WWγ gauge coupling parameters Δκγ and λγ. The results from the fit to the cross sections and to the energy and angular distributions of the photons are: Δκγ=0.05+1.15−1.10(stat)±0.25(syst), λγ=−0.05+1.55−1.45(stat)±0.30(syst).

A Work Minimization Approach To Image Morphing, Peisheng Gao, Thomas W. Sederberg

Faculty Publications

An algorithm is presented for morphing two images, often with little or no user interaction. For two similar images (such as different faces against a neutral background) the algorithm generally can create a pleasing morph completely automatically. The algorithm seeks the minimum work to deform one image into the other, where work is a function of the amount of warping and recoloration. A hierarchical method for finding a minimal work solution is invoked. Anchor point constraints are satisfied by imposing penalties on deformations that disobey these constraints. Good results can be obtained in less than ten seconds for 256 x …

Studies On The Occurrence Of Fluoride In Some Food Samples, Taghreed Ali Abdullah Al-Habshi

Theses

In recent years, the amount of fluoride in biological samples, drinking water and in fluoride containing food or feedstuffs has generated considerable interest. Hence the determination of fluoride is becoming increasingly important due to its implications for environmental health. Fluoride is considered to be amongst the most phytotoxic of the more common pollutants. In response to that extensive research has been made to improve the determination of trace amounts of fluoride through developing different analytical methods. The application of these various analytical methods for fluoride ion determination in water and food samples has gained an enormous interest.

Chapter I of …

Application Of The Paleomagnetic Fold Test To Determine The Relative Timing Of Sill Intrusion And Deformation In The Southwest Helena Salient, Montana, Stephen Christopher Whisner

Masters Theses

The Doherty Mountain fold complex is a highly folded and faulted region along the southern boundary of the Helena Salient in southwestern Montana. This region has a complex deformation history that is a key to deformation within the Helena Salient as a whole. A structural interpretation of the deformed rocks of this area was conducted using field mapping and cross section construction at 1:24,000 scale providing insight to the internal deformation processes involved. Fourteen folds and three major faults were mapped and analyzed showing the influence of the Southwest Montana Transverse Zone and late stage detachment faulting on fold orientation. …

Separation And Determination Of Monochlorophenols By Capillary Zones Electrophoresis, Zarina Yasmin Banu

Masters Theses

Chlorine has been widely used in industry. One of the most common uses of chlorine is in municipal water treatment plants. Chlorine reacts with a variety of organic compounds, among these are phenol and its derivatives which are commonly found in natural waters. When these compounds react with chlorine, a variety of chlorine substituted and oxidized products result depending on concentrations, pH, and temperature. In order to study these reactions it is necessary to separate and determine the various products produced.

Earlier studies have shown 3-chloro and 4-chlorophenol cannot be separated by commercial GLC columns. GC/MS (electron impact) measurements cannot …

Synthesis, Characterization And Photophysical Behavior Of A Cr(Iii) Bimetallic System, Yan Chen

Masters Theses

Many binuclear transition metal complexes have been studied to understand the nature of interactions between the metal centers. People have found Simultaneous Pair Excitation phenomenon in some bimetallic system that can serve as a potential source of Non-Linear Optical behavior.

Thus a series of Cr₂ -([14]aneN₄)₂-X₄ⁿ⁺ complexes were synthesized and characterized. Only the cis,cis configuration was found. The results were compared with those of their monomer analogs. The electronic structures are very similar in both monomer and dimer complexes. The quantum yield, UV-Vis absorption and lifetime studies suggested a possible coupling between the …

Essay On Deprivation, Poverty And Well-Being., Diganta Mukherjee Dr.

Doctoral Theses

Issues like inequity, deprivation and poverty have been a focus of interest for social scientists for a long time. The present thesis explores a few aspects of the above issues. It ermbodies the fruit of my intellectual perambulation in the Economic Research Unit of Indian Statistical Institute (ISI) during the years 1995 - 97. The text is divided into six chapters. The first chapter gives a general overview of different aspects of measuring inequality, deprivation and poverty. The second, third and fourth chapters take up the issue of deprivation measurement in detail. They contain discussions on deprivation ordering, indices and …