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Late-Time Behavior Of Stellar Collapse And Explosions. I. Linearized Perturbations, Carsten Gundlach, Richard H. Price, Jorge Pullin Jan 1994

Late-Time Behavior Of Stellar Collapse And Explosions. I. Linearized Perturbations, Carsten Gundlach, Richard H. Price, Jorge Pullin

Faculty Publications

We study the power-law tails in the evolution of massless fields around a fixed background geometry corresponding to a black hole. We give analytical arguments for their existence at scri+, at the future horizon, and at future timelike infinity. We confirm their existence with numerical integrations of the curved spacetime wave equation on the background of a Schwarzschild and a Reissner-Nordström black hole. These results are relevant to studies of mass inflation and the instability of Cauchy horizons. The analytic arguments also suggest the behavior of the full nonlinear dynamics, which we study numerically in a companion paper. © 1994 …

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Late-Time Behavior Of Stellar Collapse And Explosions. Ii. Nonlinear Evolution, Carsten Gundlach, Richard H. Price, Jorge Pullin Jan 1994

Late-Time Behavior Of Stellar Collapse And Explosions. Ii. Nonlinear Evolution, Carsten Gundlach, Richard H. Price, Jorge Pullin

Faculty Publications

We compare the predictions of linearized theory for the radiation produced in the collapse of a spherically symmetric scalar field with a full numerical integration of the Einstein equations. We find power-law tails and quasinormal ringing remarkably similar to predictions of linearized theory even in cases where nonlinearities are crucial. We also show that power-law tails develop even when the collapsing scalar field fails to produce a black hole. © 1994 The American Physical Society.

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Colliding Black Holes: The Close Limit, Richard H. Price, Jorge Pullin Jan 1994

Colliding Black Holes: The Close Limit, Richard H. Price, Jorge Pullin

Faculty Publications

The problem of the mutual attraction and joining of two black holes is of importance as both a source of gravitational waves and as a testbed of numerical relativity. If the holes start out close enough that they are initially surrounded by a common horizon, the problem can be viewed as a perturbation of a single black hole. We take initial data due to Misner for close black holes, apply perturbation theory, and evolve the data with the Zerilli equation. The computed gravitational radiation agrees with and extends the results of full numerical computations. © 1994 The American Physical Society.

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A Directed Hypergraph Approach For The Verification Of Rule-Based Expert Systems., Mysore Ramaswamy Jan 1994

A Directed Hypergraph Approach For The Verification Of Rule-Based Expert Systems., Mysore Ramaswamy

LSU Historical Dissertations and Theses

Rule-based representation techniques have become popular for storing and manipulation of domain knowledge in expert systems. It is important that systems using such a representation are verified for accuracy before implementation. In recent years, graphical techniques have been found to provide a good framework for the detection of errors that may appear in a rule base. In this dissertation, we develop a technique that uses a directed hypergraph to accurately detect all the different types of errors that appear in a rule base. This technique overcomes limitations of existing graphical techniques that are unable to accurately detect all the errors …

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The Influence Of Open-Mindedness And Knowledge On Attitudes Toward Teen Pregnancy And Parenting Among Home Economics Teachers., Peggy Campbell Rolling Jan 1994

The Influence Of Open-Mindedness And Knowledge On Attitudes Toward Teen Pregnancy And Parenting Among Home Economics Teachers., Peggy Campbell Rolling

LSU Historical Dissertations and Theses

The primary purpose of this study was to determine the influence of knowledge of teenage pregnancy/parenting, open-mindedness, and selected demographic characteristics on the attitudes of home economics teachers toward teenage pregnancy/parenting. The target population for the study was defined as secondary school home economics teachers employed in Louisiana during the 1993-94 school year. A simple random sample of 200 teachers was selected from the defined population. The instrument used in this study consisted of four parts. The first part was the Adolescent Parents Attitude Scale and was used to measure attitudes toward pregnant adolescents and school-age parents. The second part …

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Simulation And Testing Of A Vibrating Digger Blade For Root Crops., Luis Arnoby Rodriguez Hurtado Jan 1994

Simulation And Testing Of A Vibrating Digger Blade For Root Crops., Luis Arnoby Rodriguez Hurtado

LSU Historical Dissertations and Theses

The performance of a vibrating digger blade machine was simulated in the laboratory and evaluated in the laboratory and in the field. The machine generated three modes of vibration: horizontal, vertical and their combination. A set of fifty-two tests replicated three times were performed in the field by varying amplitude (2 values), forward speed (2 values), and velocity ratio (2 values) for horizontal and vertical oscillation and amplitude combination (4 values), forward speed (2 values) and phase angle (4 values) for combined vibration. The tests were conducted in a silty-loam soil with the following characteristics: bulk density 1115.2 kg/m$\sp3$, moisture …

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Photoemission Studies Of Electronic Dispersion In Metals And Thin Film Systems., Zhe Qu Jan 1994

Photoemission Studies Of Electronic Dispersion In Metals And Thin Film Systems., Zhe Qu

LSU Historical Dissertations and Theses

We have studied the electronic dispersion of Cu and the Cu/Ru(0001) bimetallic system using photoelectron spectroscopy. Images of electron emission from Cu(100), Cu(111), and Cu/Ru(0001) have been obtained using an ellipsoidal-mirror analyzer (EMA). This energy analyzer collects photoemitted electrons over a large solid angle, preserving their angular information and providing an image of intensity versus emission angle. The images provide direct information on band dispersion. The surface state of Cu(111) was measured using the EMA at different binding energies. By combining these images, we have obtained the surface state dispersion in three dimensional E vs k space. Our results are …

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Dynamic Behavior Of Magnetic Latex Particles And Polyelectrolytes., Daewon Sohn Jan 1994

Dynamic Behavior Of Magnetic Latex Particles And Polyelectrolytes., Daewon Sohn

LSU Historical Dissertations and Theses

The dynamic behavior of magnetic latex particles has been explored. Polarized and depolarized dynamic light scattering from binary and ternary systems of these particles have provided rotational and translational diffusion coefficients. Microscopic views of rotational and translational diffusion of these particles are compared with macroscopic viscosity from the Stokes-Einstein equation (Chapter 2). The polymeric stabilization of magnetic latex particles has also been investigated by static and dynamic light scattering. Using the optical anisotropy of magnetic latex particles, the translational and rotational diffusion coefficients of the particles under various salt conditions were determined. The stability of the superparamagnetic latex particles depends …

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A Study Of The Abundances Of Light Isotopes In Cosmic Rays With A Superconducting Magnet Instrument., Michal Lijowski Jan 1994

A Study Of The Abundances Of Light Isotopes In Cosmic Rays With A Superconducting Magnet Instrument., Michal Lijowski

LSU Historical Dissertations and Theses

The balloon-borne Superconducting Magnet Instrument for Light Isotopes flew for the second time on July 24-25, 1991 at the altitude of 36 km during conditions of extremely high solar modulation. The detector was designed to measure the charge, rigidity, and velocity of cosmic rays heavier than hydrogen within the kinetic energy range 100-2000 MeV/nucleon. The helium spectrum measured over this wide energy range is consistent with an interstellar helium spectrum expressed as a power law in the rigidity with spectral index of $-$2.68 and modulated to a level given by the solar modulation parameter $\phi$ = 1.5 GV. The $\sp2$H/$\sp4$He …

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An Ethnographically Informed Case Study Of An Art Teacher Using Right Brain Drawing Instruction., Sara Jan Smith Jan 1994

An Ethnographically Informed Case Study Of An Art Teacher Using Right Brain Drawing Instruction., Sara Jan Smith

LSU Historical Dissertations and Theses

The first and central purpose of this study was to identify and describe one high school art teacher's basis for incorporating into the curriculum right-brain drawing instruction based on Edwards' (1989) book, Drawing on the Right Side of the Brain. The second was to provide art educators with preliminary information about the right-brain theory's popularity that might assist them in future research on a larger scale. Computer searches of ERIC and PSYCH INFO were conducted to locate related research findings dealing with hemispheric function. The empirical findings were analyzed and compared to rationales for employing right-brain teaching strategies. The research …

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An Incremental Navigation Localization Methodology For Application To Semi-Autonomous Mobile Robotic Platforms To Assist Individuals Having Severe Motor Disabilities., Daryl Devon Thomas Jan 1994

An Incremental Navigation Localization Methodology For Application To Semi-Autonomous Mobile Robotic Platforms To Assist Individuals Having Severe Motor Disabilities., Daryl Devon Thomas

LSU Historical Dissertations and Theses

In the present work, the author explores the issues surrounding the design and development of an intelligent wheelchair platform incorporating the "semi-autonomous" system paradigm, to meet the needs of individuals with severe motor disabilities. The author presents a discussion of the problems of navigation that must be solved before any system of this type can be instantiated, and enumerates the general design issues that must be addressed by the designers of systems of this type. This discussion includes reviews of various methodologies that have been proposed as solutions to the problems considered. Next, the author introduces a new navigation method, …

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Palmerston, Parliament And Peking: The Melbourne Ministry And The Opium Crisis, 1835-1840., Glenn Paul Melancon Jan 1994

Palmerston, Parliament And Peking: The Melbourne Ministry And The Opium Crisis, 1835-1840., Glenn Paul Melancon

LSU Historical Dissertations and Theses

"Palmerston, Parliament and Peking" is a revisionist work designed to challenge the prevailing economic interpretations of the first Opium War, 1839-1842. Orthodox historiography considers early nineteenth-century Britain as a modern, industrial society and argues that its Government needed to respond violently to the Chinese authorities' suppression of the opium trade in order to protect and expand a lucrative endeavor. Indian opium sales generated revenue for the British-run government in Bengal and paid for Chinese tea, a highly prized commodity in Great Britain. British industrialists demanded war to end the Chinese Government's restrictions on trade, known as the Canton system, thus …

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Feasibility Studies Of Radionuclide Removal From Kaolinite By Electrokinetic Soil Processing., Dionisio Alberto Ugaz Jan 1994

Feasibility Studies Of Radionuclide Removal From Kaolinite By Electrokinetic Soil Processing., Dionisio Alberto Ugaz

LSU Historical Dissertations and Theses

Electrokinetic soil processing is an emerging remediation technique with the capability to decontaminate low permeability soils containing heavy metals and some organics. The process consists on applying small current densities between electrodes immersed in the soil mass; the electrochemistry developed across the system causes desorption and transport of the contaminants to the electrodes where, depending on their chemistry, they precipitate, electrodeposit, or elute with the electroosmotic flow. Its potential to remove selected radionuclides (uranium-238, thorium-232, and radium-226) is assessed in the present studies. The process removed 85 to 95% uranium-238 at 1000 pCi/g activity from kaolinite. Complicating features arise (i.e. …

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Extremely High Field Nmr Techniques And Instrumentation For The Study Of Catalysts And Materials., Xiao Wu Jan 1994

Extremely High Field Nmr Techniques And Instrumentation For The Study Of Catalysts And Materials., Xiao Wu

LSU Historical Dissertations and Theses

The main goal of the research presented in this dissertation is to develop and apply solid-state nuclear magnetic resonance (NMR) techniques to study catalytic materials. Several solid state NMR techniques were developed and have been applied to a series of catalyst systems. The construction and operation of several NMR spectrometers, and the design of NMR probes are discussed. The most novel is a broadband pulsed NMR spectrometer with digital phase shifting and a 0 to 18 Tesla magnet. The development and construction of a field-swept NMR spectrometer is described in detail. This instrument provides a means of acquiring high-quality solid …

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Finite Element Analysis Of Damage And Elastic-Plastic Behavior Of Metal Matrix Composites., Taehyo Park Jan 1994

Finite Element Analysis Of Damage And Elastic-Plastic Behavior Of Metal Matrix Composites., Taehyo Park

LSU Historical Dissertations and Theses

Damage and elasto-plastic analysis is of particular importance to metal matrix composites since the onset of damage and plastic yielding begins very early in the loading process as compared to the composites ultimate strength. Two types of damage models are proposed using micromechanical model. A finite element analysis is presented for quantifying damage and predicting the failure loads of the center-cracked laminate metal matrix composite plates. Both the overall damage model which accounts for all types of damages as a single damage variable and the local damage model which uses the local constitutive damage relations for each of the matrix …

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Alignment System For X-Ray Lithography., Hao Zhou Jan 1994

Alignment System For X-Ray Lithography., Hao Zhou

LSU Historical Dissertations and Theses

Among the various contenders for VLSI lithography below 0.1 $\mu$m, proximity x-ray printing is the most promising one and has been investigated for many years. It will require overlay accuracy far below 100 nm, 3$\sigma$, typical of today's systems. In addition, it should use wafer marks that permit planar resist flow, so their apparent position is not distorted. We have demonstrated an alignment system that uses a linear zone plate on the mask to focus laser light into a line on the wafer. The wafer mark is the boundary between two adjacent fine pitch gratings. These gratings diffract the light …

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Gwen Bristow: A Biography With Criticism Of Her "Plantation Trilogy"., Billie J. Theriot Jan 1994

Gwen Bristow: A Biography With Criticism Of Her "Plantation Trilogy"., Billie J. Theriot

LSU Historical Dissertations and Theses

Gwen Bristow was born September 16, 1903. Her father was a minister and church leader and her mother was a homemaker and housemother for residents of Southern Baptist Hospital nurses' home. Both had impressive genealogies. Bristow, a reporter in New Orleans for The Times-Picayune from July 9, 1925, to November 28, 1930, and February 5, 1932, to September 21, 1934, wrote for many periodicals throughout her life. Her marriage to Bruce Manning took her to Hollywood, where she lived from the summer of 1934 until late spring 1980. Bruce Manning's career as a script writer, director, and producer provided a …

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A Study Of The Radiative Properties Of Agglomerated Flame Particulates Using Light Scattering., Demetris Theodosios Venizelos Jan 1994

A Study Of The Radiative Properties Of Agglomerated Flame Particulates Using Light Scattering., Demetris Theodosios Venizelos

LSU Historical Dissertations and Theses

The in-situ optical technique of inferring the soot agglomerate structural and optical properties from the measurements of the extinction cross section, the differential scattering cross section, the dissymmetry ratios in both planes of polarization, and the depolarization ratio, was investigated in detail by this study. A sensitivity analysis of the technique revealed that the dissymmetry ratios are insensitive to both the real and imaginary part of the refractive index. The ratio of the differential scattering to extinction cross sections was also found to be a weak function of the imaginary part of the refractive index. The sensitivity analysis results indicate …

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A Specification Environment That Supports The Prototyping Of Distributed Systems Using An Object-Oriented Model., Abbas Dehkhoda Jan 1994

A Specification Environment That Supports The Prototyping Of Distributed Systems Using An Object-Oriented Model., Abbas Dehkhoda

LSU Historical Dissertations and Theses

High-speed computer networking, interactive service, and incremental growth for computing are some of the motivations for developing a distributed system. Despite the inherent benefits of a distributed system, the development of software support is more difficult for distributed systems than for sequential systems. In either case, difficulties may arise from the communication problems between two groups of people with different backgrounds trying to formulate requirements for the system. This process depends on feedback and may take many iterations to converge. Customers can usually recognize the features they need when they start using a system, which makes prototyping an important tool …

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Effects Of Heat, Lactic Acid, And Modified Atmosphere Packaging On Listeria Monocytogenes On Cooked Crawfish Tail Meat., Warren Joseph Dorsa Jan 1994

Effects Of Heat, Lactic Acid, And Modified Atmosphere Packaging On Listeria Monocytogenes On Cooked Crawfish Tail Meat., Warren Joseph Dorsa

LSU Historical Dissertations and Theses

The generation time of L. monocytogenes was calculated to be 72.2, 28.5, 17.01, and 6.9 h on crawfish tail meat held at 0, 4, 6, and 12$\sp\circ$C, respectively. Potassium sorbate (PS) (0.3%) spray treatments on crawfish held at 4$\sp\circ$C, extended the lag phase of the bacterium. However, once exponential growth began, a generation time not significantly different (P $>$ 0.05) than that of untreated crawfish was observed. Samples sprayed with 0.3% citric acid (CA) and held at 4$\sp\circ$C supported growth of the bacterium equally well as that of untreated samples. Thermal inactivation of L. monocytogenes using a three neck …

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A Comparison Of The Effects Of Multiple Visual Examples And Nonexamples Versus Prototypical Examples On Science Concept Learning: An Exploratory Study Based Upon The Concept Of Photosynthesis., Eleanor Deane Abrams Jan 1994

A Comparison Of The Effects Of Multiple Visual Examples And Nonexamples Versus Prototypical Examples On Science Concept Learning: An Exploratory Study Based Upon The Concept Of Photosynthesis., Eleanor Deane Abrams

LSU Historical Dissertations and Theses

Two researcher-produced, standard-length videos on photosynthesis (and accompanying ancillary materials) were developed with the input of educators and content experts. The control treatment video script contained the standard number of prototypical examples and graphics based high school textbooks. The experimental treatment video script was based on the theory of conceptual change. Two student focus groups met daily for one week and reviewed portions of the original experimental treatment script for clarity, brevity, and choice and placement of examples and nonexamples. Their suggestions and conceptual change have implications for curriculum design. The main research question of this study was: Do students …

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Modeling Transport Of Non Aqueous Wastes In Unsaturated Soils., Dharmesh Vinaychandra Doshi Jan 1994

Modeling Transport Of Non Aqueous Wastes In Unsaturated Soils., Dharmesh Vinaychandra Doshi

LSU Historical Dissertations and Theses

In evaluating risks associated with chemical spills on the ground surface or leaks from underground storage tanks, it is required to know the extent and degree of contamination in the subsurface. In many cases pure organics are spilled and due to their low miscibility with water they remain pure or concentrated for some distance or time from the source. This dissertation is aimed at developing a model of the multiphase (air, water, organic) migration processes. The particular focus is on modeling organic infiltration in the unsaturated zone where the transport is largely vertical. Sand-column experiments using a variety of immiscible …

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A Study Of Nontraditional Referral And Screening Of Culturally Different Gifted Children., Jo Anne Welch Jan 1994

A Study Of Nontraditional Referral And Screening Of Culturally Different Gifted Children., Jo Anne Welch

LSU Historical Dissertations and Theses

The purpose of this study was to determine the effectiveness of using nontraditional referral and screening procedures to identify culturally different (minority) gifted children. The extreme disparity of representative frequencies of these groups within gifted programs nationally and in Louisiana prompted research in four parishes (counties) to compare nontraditional with traditional identification procedures. The nontraditional referral procedures included child search methods and parent and teacher training about the characteristics of giftedness among culturally different populations. Nontraditional screening procedures included the use of creativity and leadership checklists, analysis of achievement in all academic areas, and the use of the Matrix Analogies …

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The Ten Violin Concertos Of Charles-Auguste De Beriot: A Pedagogical Study., Nicole De Carteret Hammill Jan 1994

The Ten Violin Concertos Of Charles-Auguste De Beriot: A Pedagogical Study., Nicole De Carteret Hammill

LSU Historical Dissertations and Theses

Charles-Auguste de Beriot (1802-70) was a Belgian violinist, composer, and teacher. He was trained in his youth in Belgium and in the early 1820s travelled to Paris and studied briefly with the noted teacher Pierre Baillot at the Paris Conservatoire. He then embarked upon a solo career and from 1829 to 1836 he toured with the famed opera singer Maria Malibran, whom he married in 1836. In 1842, after declining an offer to replace Baillot at the Paris Conservatoire, Beriot accepted a position at the Brussels Conservatoire. He remained there until his retirement due to failing eyesight in 1852, and …

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Personal And Occupational Mobility Characteristics Of Selected Dislocated Newspaper Workers., Jackie Lamar Benton Jan 1994

Personal And Occupational Mobility Characteristics Of Selected Dislocated Newspaper Workers., Jackie Lamar Benton

LSU Historical Dissertations and Theses

The purpose of this study was to describe the personal and occupational mobility characteristics of selected dislocated newspaper workers and the residual effect of their separation and unemployment. Objectives of the descriptive study focused on: (a) demographic characteristics, (b) employment history, (c) occupational mobility, (d) economic and emotional impact, (e) attitudes and perceptions, and (f) education and training. A defined population of 132 dislocated newspaper workers was surveyed six and 18 months after departure from the industry. The researcher-designed survey instrument had 41 items (six months) and 43 items (18 months). Sixty-four dislocated newspaper workers responded at six months, and …

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Fluorescence Studies Of Tomaymycin-Dna Adducts: Structure And Dynamics., Qi Chen Jan 1994

Fluorescence Studies Of Tomaymycin-Dna Adducts: Structure And Dynamics., Qi Chen

LSU Historical Dissertations and Theses

The relationship between ground-state structure and fluorescence lifetime of tomaymycin was studied using steady-state and time-resolved fluorescence, absorption, NMR, and photochemical techniques. Excited-state proton transfer and intersystem crossing were identified as the major nonradiative processes. Solvent isotope effect was found in aqueous solution, which did not involved C8OH. Photochemical H-D exchange on aromatic C6H and C9H were observed with similar rate. At 77 K, the total luminescence quantum yield was determined as 0.99. The quantum yield ratio of phosphorescence to fluorescence was 1.2. The limiting anisotropy was ${\sim}0.34$ for fluorescence and $-$0.1 for phosphorescence. The number and type of tomaymycin-DNA …

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Patterns Of Adaptive Functioning In Cortical And Subcortical Diagnostic Groups Of Dementia., Paul Matthew Dammers Jan 1994

Patterns Of Adaptive Functioning In Cortical And Subcortical Diagnostic Groups Of Dementia., Paul Matthew Dammers

LSU Historical Dissertations and Theses

Much debate exists as to the independence of subcortical dementia as a recognizable clinical entity. Researchers in the dementia area seem to accept that cortical dementias are relatively more incapacitating than subcortical dementias. However, there are no empirical studies to support this claim. Impairment in adaptive functioning is one criterion to be met in the diagnosis of dementia according to DSM-III-R (APA, 1987) and NINCDS-ADRDA criteria (McKhann, Drachman, Folstein et al., 1984). However, a comparison of the degree of impairment in adaptive functioning between subcortical and cortical diagnostic groups of dementia has never been systematically and empirically investigated. This study …

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On Information Usage Modeling., Ping Pete Chong Jan 1994

On Information Usage Modeling., Ping Pete Chong

LSU Historical Dissertations and Theses

Although it is well-known that the usage of information usually follows the 80/20 rule and concentrates on a few items, there has not been an analytical model to depict this skew distribution. This dissertation provides a theoretical foundation, based on Simon's modeling of empirical phenomena and Chen's index approach, to identify the factors which shape this usage pattern. Using Chen's index approach, we conclude that the distance and slope of the data points determine the shape of the distribution. We further examine the critical parameters in Simon's model through computer simulations, and we find the probability of new entry ($\alpha$) …

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Second Order Neural Networks., Sanjoy Das Jan 1994

Second Order Neural Networks., Sanjoy Das

LSU Historical Dissertations and Theses

In this dissertation, a feedback neural network model has been proposed. This network uses a second order method of convergence based on the Newton-Raphson method. This neural network has both discrete as well as continuous versions. When used as an associative memory, the proposed model has been called the polynomial neural network (PNN). The memories of this network can be located anywhere in an n dimensional space rather than being confined to the corners of the latter. A method for storing memories has been proposed. This is a single step method unlike the currently known computationally intensive iterative methods. An …

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Neogene Extension And Regional Rotation Of The Central Mojave Desert, California., Timothy Michael Ross Jan 1994

Neogene Extension And Regional Rotation Of The Central Mojave Desert, California., Timothy Michael Ross

LSU Historical Dissertations and Theses

The southwest Cady Mountains of San Bernardino County, California, contain key relationships which allow separation of the timing of early Miocene detachment-style extension and vertical-axis clockwise rotation in the Mojave Desert. The rock succession consists of a pre-Tertiary granitic basement overlain by three successive volcanic and volcaniclastic units of early to middle Miocene age referred to informally as the formation of Poe, the formation of Troy Peak and the "Barstow Formation". Deposition of the volcanic upper Oligocene/lower Miocene formation of Poe was accompanied by extension and tilting, facilitated by faults which do not cut the unconformably overlying formation of Troy …

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