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Articles 3301 - 3330 of 3676

Full-Text Articles in Physical Sciences and Mathematics

An Investigation Of A Salt-Dome Environment At South Timbalier 54, Gulf Of Mexico, Robert E. Little, Jr Jan 2003

An Investigation Of A Salt-Dome Environment At South Timbalier 54, Gulf Of Mexico, Robert E. Little, Jr

LSU Master's Theses

Salt domes have been studied in the Gulf Coast region to look at how, why, and where saline waters are located within these field areas. Fluid flow model and pathway studies can be helpful to the research of saline water migration because it can be correlated to hydrocarbon migration in petroleum exploration. The South Timbalier 54 field occurs over a salt dome that sits at approximately 3,048 meters beneath the seafloor. Two major faults were found originating from the salt dome up into the shallow section of the field. The sands were deposited in fluvial, deltaic, or marine environments. The …

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Using Functional Distance Measures When Calibrating Journey-To-Crime Distance Decay Algorithms, Joshua David Kent Jan 2003

Using Functional Distance Measures When Calibrating Journey-To-Crime Distance Decay Algorithms, Joshua David Kent

LSU Master's Theses

Spatial analysis has long been a valuable tool used within the criminal investigative process. This is especially true for serial offence cases where criminologists apply geographic profiling to model offender mobility and crime distribution patterns in order to estimate a criminal’s likely residence. Yet, traditional analytical methodologies have avoided the utilization of functional distance measures when modeling an offender’s journey-to-crime within an anisotropic landscape. By substituting straight-line Euclidean distances with travel path functional distance measures, the predictive utility and technological prerequisites associated with geographically profiling a localized serial offender was assessed using mathematically calibrated distance decay models. Both the travel-path …

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A Risk-Averse Strategy For Blackjack Using Fractional Dynamic Programming, Ryan A. Dutsch Jan 2003

A Risk-Averse Strategy For Blackjack Using Fractional Dynamic Programming, Ryan A. Dutsch

LSU Master's Theses

We present how blackjack is related to a discrete-time control problem, rather than a zero-sum game. Using the compiler Visual C++, we write a program for a strategy for blackjack, but instead of maximizing the expected value, we use a risk-averse approach. We briefly describe how this risk-averse strategy is solved by using a special type of dynamic programming called fractional dynamic programming.

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Correlation Of Core Characteristics To Outcrop Upper Jackfork Group Turbidites, Degray Lake, Arkansas, Daniel James Golob Jan 2003

Correlation Of Core Characteristics To Outcrop Upper Jackfork Group Turbidites, Degray Lake, Arkansas, Daniel James Golob

LSU Master's Theses

Pennsylvanian age Jackfork Group cores from the DeGray Lake Dam and outcrop from the east wall of the DeGray Lake Spillway, Arkansas, provide an opportunity for a detailed study on the transport and depositional characteristics of a fine-grained, deep-water depositional system. Two phases of resedimentation processes are responsible for deposition of the sediments in the cores and the outcrop. Primary resedimentation processes transport terrigenous sediments from the shelf or basin edge into the middle fan environment, while secondary resedimentation alter the sediments after they are initially deposited in the environment. Debris flows, slurry flows, and high and low density turbidity …

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Regional Water Quality Models For The Prediction Of Eutrophication Endpoints, Anindita Das Jan 2003

Regional Water Quality Models For The Prediction Of Eutrophication Endpoints, Anindita Das

LSU Master's Theses

Eutrophication is a process by which a waterbody progresses from its origin to its extinction. During this period, there is a gradual accumulation of nutrients and organic biomass, accompanied by a decrease in average depth of the water due to sediment accumulation, and an increase in primary productivity, usually in the form of dense algal blooms. Cultural eutrophication occurs when humans, through their various activities, greatly accelerate this process. Eutrophication can cause loss in species diversity, fish kills, and decrease the aesthetic value of a waterbody. The EPA is trying to prevent cultural eutrophication by setting standards for water quality …

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Scalable Parallel Molecular Dynamics Algorithms For Organic Systems, Satyavani Vemparala Jan 2003

Scalable Parallel Molecular Dynamics Algorithms For Organic Systems, Satyavani Vemparala

LSU Master's Theses

A scalable parallel algorithm, Macro-Molecular Dynamics (MMD), has been developed for large-scale molecular dynamics simulations of organic macromolecules, based on space-time multi-resolution techniques and dynamic management of distributed lists. The algorithm also includes the calculation of long range forces using Fast Multipole Method (FMM). FMM is based on the octree data structure, in which each parent cell is divided into 8 child cells and this division continues until the cell size is equal to the non-bonded interaction cutoff length. Due to constant number of operations performed at each stage of the octree, the FMM algorithm scales as O(N). Design and …

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Equations Of Parametric Surfaces With Base Points Via Syzygies, Haohao Wang Jan 2003

Equations Of Parametric Surfaces With Base Points Via Syzygies, Haohao Wang

LSU Doctoral Dissertations

Suppose $S$ is a parametrized surface in complex projective 3-space $mathbf{P}^3$ given as the image of $phi: mathbf{P}^1 imes mathbf{P}^1 o mathbf{P}^3$. The implicitization problem is to compute an implicit equation $F=0$ of $S$ using the parametrization $phi$. An algorithm using syzygies exists for computing $F$ if $phi$ has no base points, i.e. $phi$ is everywhere defined. This work is an extension of this algorithm to the case of a surface with multiple base points of total multiplicity k. We accomplish this in three chapters. In Chapter 2, we develop the concept and properties of Castelnuovo-Mumford regularity in biprojective spaces. …

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Toward A Sustainable Energy Future?: A Comparison Between U.S. And European Energy Sectors, Annett Moehner Jan 2003

Toward A Sustainable Energy Future?: A Comparison Between U.S. And European Energy Sectors, Annett Moehner

LSU Master's Theses

Since 1987, the concept of sustainable development, which tries to combine economic, social and environmental concerns into one benign development model, has become increasingly popular worldwide. To explore and explain the differences in accomplishing sustainable development, this thesis looks at one specific aspect: the energy sectors in the United States and the European Union. After giving an overview on the political and theoretical aspects of sustainable development, the various sustainability dimensions in the energy sector are explored. The following four reasons which warrant the change of the current fossil fuel intense energy sector are discussed: first, air pollution; second, insecurity …

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Analyzing The Impact Of Changing Software Requirements: A Traceability-Based Methodology, James Steven O'Neal Jan 2003

Analyzing The Impact Of Changing Software Requirements: A Traceability-Based Methodology, James Steven O'Neal

LSU Doctoral Dissertations

Software undergoes change at all stages of the software development process. Changing requirements represent risks to the success and completion of a project. It is critical for project management to determine the impact of requirement changes in order to control the change process. We present a requirements traceability based impact analysis methodology to predictively evaluate requirement changes for software development projects. Trace-based Impact Analysis Methodology (TIAM) is a methodology utilizing the trace information, along with attributes of the work products and traces, to define a requirement change impact metric for determining the severity of a requirement change. We define the …

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On The Geometry And Topology Of Moduli Spaces Of Multi-Polygonal Linkages, Michael Edward Holcomb Jan 2003

On The Geometry And Topology Of Moduli Spaces Of Multi-Polygonal Linkages, Michael Edward Holcomb

LSU Doctoral Dissertations

The geometric, topological, and symplectic properties of moduli spaces (spaces of configurations modulo rotations and translations) of polygonal linkages have been studied by Kapovich, Millson, and Kamiyama, et. al. One can form a polygonal linkage by taking two free linkages and identifying initial and terminal vertices. This can be generalized so that one takes three free linkages and identifies initial and terminal vertices. Then one obtains a linkage which contains multiple polygons, any two of which have shared edges. The geometric and topological properties of moduli spaces of these multi-polygonal linkages are studied. These spaces turn out to be compact …

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Constraint Preserving Boundary Conditions For The Linearized Einstein Equations, Gioel Calabrese Jan 2003

Constraint Preserving Boundary Conditions For The Linearized Einstein Equations, Gioel Calabrese

LSU Doctoral Dissertations

The successful construction of long time convergent finite difference schemes approximating highly gravitating systems in general relativity remains an elusive task. The presence of constraints and the introduction of artificial time-like boundaries contribute significantly to the difficulty of this problem. Whereas in the absence of boundaries the Bianchi identities ensure that the constraints vanish during evolution provided that they are satisfied initially, this is no longer true when time-like boundaries are introduced. In this work we consider the linearization around the Minkowski space-time in Cartesian coordinates of the generalized Einstein-Christoffel system and analyze different kinds of boundary conditions that are …

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Genome Analysis: Mutation Analysis Using Near Infrared Laser-Induced Fluorescence (Nir-Lif) And Single Molecule Detection In Microfluidic Devices, Musundi Ben Wabuyele Jan 2003

Genome Analysis: Mutation Analysis Using Near Infrared Laser-Induced Fluorescence (Nir-Lif) And Single Molecule Detection In Microfluidic Devices, Musundi Ben Wabuyele

LSU Doctoral Dissertations

A number of genotyping methods have been developed for mutation analysis, each of which has its own unique advantage. DNA amplification via polymerase chain reaction (PCR) provides an unlimited supply of material for subsequent genetic analysis even in case where only a single copy of the DNA molecule is present in the sample. Research presented in this dissertation first examines the efficiency of in vitro amplification of single copy DNA with subsequent sequencing analysis of PCR product. The PCR products (amplicons) were investigated for possible alteration, distortions or mutations due to the amplification process. The sequencing data for single copy …

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Group Theoretical Approach To Pairing And Non-Linear Phenomena In Atomic Nuclei, Kristina D. Launey Jan 2003

Group Theoretical Approach To Pairing And Non-Linear Phenomena In Atomic Nuclei, Kristina D. Launey

LSU Doctoral Dissertations

The symplectic sp(4) algebra provides a natural framework for studying proton-neutron (pn) and like-nucleon pairing correlations as well as higher-J pn interactions in nuclei when protons and neutrons occupy the same shell. While these correlations manifest themselves most clearly in the binding energies of 0+ ground states, they also have a large effect on the spectra of excited isobaric analog 0+ states. With a view towards nuclear structure applications, a fermion realization of sp(4) is explored and its q-deformed extension, sp(4)q, is constructed for single and multiple shells. The su(2)(q) substructures that enter are associated with isospin symmetry and with …

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Level Of Essentialness Of A Node In Flowcharts And Its Application To Program Testing, Osman Kandara Jan 2003

Level Of Essentialness Of A Node In Flowcharts And Its Application To Program Testing, Osman Kandara

LSU Doctoral Dissertations

Program testing is important to develop bug free software. A common form of program testing involves selecting test cases which execute (cover) a given set W of statements in the program. In regression testing, W typically forms a small subset of the program. It is often possible to find an alternate small set W so that execution of W' implies execution of W. We develop concepts and algorithms for finding W' as small as possible with the condition that the statements in W' are "close" to those in W in terms of program structure. These concepts generalize the notion of …

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Abundance Trends And Environmental Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Lower Barataria And Caminada Bays, Louisiana, Cara Edina Miller Jan 2003

Abundance Trends And Environmental Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Lower Barataria And Caminada Bays, Louisiana, Cara Edina Miller

LSU Doctoral Dissertations

The paucity of research into the environmental requirements, stock membership, abundance and residency patterns of bottlenose dolphins (Tursiops truncatus) in coastal Louisiana creates difficulty in understanding how local ecosystems and threats (such as fishery interactions, habitat degradation and pollution) affect populations. This study combined fine-scale environmental measurements and photo-identification techniques to describe patterns of habitat usage and abundance of bottlenose dolphins in lower Barataria Basin from June 1999 to May 2002. In addition I investigated the validity and limitations of using mark-recapture models to estimate abundance from cetacean photo-identification data. Bottlenose dolphins were present year-round in a wide range of …

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Molecular-Dynamics Simulations Of Self-Assembled Monolayers (Sam) On Parallel Computers, Satyavani Vemparala Jan 2003

Molecular-Dynamics Simulations Of Self-Assembled Monolayers (Sam) On Parallel Computers, Satyavani Vemparala

LSU Doctoral Dissertations

The purpose of this dissertation is to investigate the properties of self-assembled monolayers, particularly alkanethiols and Poly (ethylene glycol) terminated alkanethiols. These simulations are based on realistic interatomic potentials and require scalable and portable multiresolution algorithms implemented on parallel computers. Large-scale molecular dynamics simulations of self-assembled alkanethiol monolayer systems have been carried out using an all-atom model involving a million atoms to investigate their structural properties as a function of temperature, lattice spacing and molecular chain-length. Results show that the alkanethiol chains tilt from the surface normal by a collective angle of 25o along next-nearest neighbor direction at 300K. At …

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A Comparison Of Life Histories And Ecological Aspects Among Snappers (Pisces: Lutjanidae), Fernando Martinez-Andrade Jan 2003

A Comparison Of Life Histories And Ecological Aspects Among Snappers (Pisces: Lutjanidae), Fernando Martinez-Andrade

LSU Doctoral Dissertations

An extensive search for data on life-history and ecological variables was conducted for a representative number of the species within the family Lutjanidae. After creating different databases and standardizing all data, these variables were examined in statistical, correlation and graphic analyses. Additionally, a series of Principal Component Analyses were used to examine patterns among variables. Life-history variables included age at length zero, asymptotic length, maximum length, longevity, asymptotic weight, length at maturity, age at maturity, reproductive life span, growth rate and mortality rate. Ecological variables included latitudinal and vertical distribution, habitat selection (represented by substrate type), and spawning seasons. The …

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Toward A Global Microscopic Theory For Nuclear Structure: Mean Field Plus Random Phase Approximation Vs. Shell Model, Ionel Stetcu Jan 2003

Toward A Global Microscopic Theory For Nuclear Structure: Mean Field Plus Random Phase Approximation Vs. Shell Model, Ionel Stetcu

LSU Doctoral Dissertations

Our understanding of nuclear structure is built upon mean-field theories such as Hartree-Fock and time-dependent Hartree-Fock. The small-amplitude limit of the latter is the random phase approximation (RPA), which is widely used to model giant resonances in nuclei. Despite this popularity, RPA has been mostly validated against toy models; tests against complex models are scarce in the literature. We perform a thorough test of the RPA against full 0hw shell model (SM) calculations, including in our investigation binding energies, scalar ground-state observables, for which we develop a new method, and transition strengths. We allow deformed Hartree-Fock solutions and compare results …

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Parallel Molecular Dynamics Simulations Of Dynamics Of Oxidation And Reactive Wetting In Metal/Ceramic Systems, Gurcan Aral Jan 2003

Parallel Molecular Dynamics Simulations Of Dynamics Of Oxidation And Reactive Wetting In Metal/Ceramic Systems, Gurcan Aral

LSU Doctoral Dissertations

Oxidation of a flat aluminum (111) surface and the reactive wetting of the aluminum (Al) droplet on a flat alumina (α-Al2O3) surface are investigated by using parallel molecular-dynamics simulations with dynamic charge transfer among atoms on a microscopic length scale. The interatomic potential, based on the formalism of Streitz and Mintmire, allows atoms to vary their charges dynamically between anions and cations, when atoms move and their local environment is altered. We investigate the oxidation thickness as a function of time and the oxygen density which is 10-40 times that of the normal state (1 atm …

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Biomechanical Reconstruction Of The Appendicular Skeleton In Three North American Jurassic Sauropods, Ray Wilhite Jan 2003

Biomechanical Reconstruction Of The Appendicular Skeleton In Three North American Jurassic Sauropods, Ray Wilhite

LSU Doctoral Dissertations

Forelimb and hindlimb articulation, reconstructed musculature, and function were examined in Apatosaurus, Diplodocus, and Camarasaurus. A technique was developed using a Microscribe three-dimensional digitizer to capture external morphological data for skeletal reconstruction and determination of taxonomically useful features. The appendicular musculature of Alligator mississippiensis was dissected to determine form, function, origin, and insertion of muscles to aid in reconstruction of sauropod musculature. Contrary to the literature, M. caudofemoralis longus was found to originate primarily from the lateral surfaces of the proximal chevrons instead of the bodies and transverse processes of the caudals, demonstrating that chevron morphology is indicative of the …

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Synchrotron Radiation As A Probe Of Chemical Information Using Novel Experimental Configurations, George Farquar Jan 2003

Synchrotron Radiation As A Probe Of Chemical Information Using Novel Experimental Configurations, George Farquar

LSU Doctoral Dissertations

Determination of chemical information with synchrotron radiation is an area of great scientific interest, and expanding the range of available techniques is the topic of this dissertation. The experimental methods described herein allows for a significant advancement of the availability of subtle chemical information. This dissertation uses ionizing radiation to study three chemical systems. First, the l=3 shape resonance in CO is investigated using a cryogenically cooled gas jet. Shape resonant effects have been studied for many years. Previously, this was accomplished on the vibrational structure of molecules with a limited ability to determine the rotational substructure effects. A dramatic …

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Diffusion Of A Rodlike Virus In Complex Solutions, Randall Charles Cush Jan 2003

Diffusion Of A Rodlike Virus In Complex Solutions, Randall Charles Cush

LSU Doctoral Dissertations

Entanglement phenomena in concentrated polymer solutions remain an interesting and challenging problem. It is still unclear how entanglement onset affects polymer chain motion at small distance scales. One way to study such motion is to follow the diffusion of a probe particle while increasing the concentration of the polymer. Many such studies have been done using probes ranging from linear and star polymers to various colloidal particles; however, relatively few studies have used rodlike probes. Rodlike probes are potentially more interesting due to the added information that may be gained by following rotational as well as translational diffusion. The anisotropic …

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Design And Synthesis Of Constrained Dipeptide Units For Use As Β-Sheet Promoters, Umut Oguz Jan 2003

Design And Synthesis Of Constrained Dipeptide Units For Use As Β-Sheet Promoters, Umut Oguz

LSU Doctoral Dissertations

The study of factors promoting beta-sheet formation has recently gained interest due to the suspected involvement of beta-sheets in brain degenerative diseases such as Alzheimer's disease (AD), Creutzfeldt-Jacob disease (CJD) and bovine spongiform encephalopathy. Understanding beta-sheet formation and the factors that stabilize beta-sheet structure may serve as a basis for future drug design. The extended structure of a beta-sheet can be stabilized by constrained amino acid analogs that are pre-organized to adopt the extended conformation. In this dissertation using innovative synthetic organic chemistry methods, two dipeptide units are designed and synthesized that are constrained to form the extended conformation and …

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Design And Synthesis Of Handles For Solid-Phase Peptide Synthesis And Convergent Peptide Synthesis, Jose Giraldes Jan 2003

Design And Synthesis Of Handles For Solid-Phase Peptide Synthesis And Convergent Peptide Synthesis, Jose Giraldes

LSU Doctoral Dissertations

The recent popularity of methods for solid-phase peptide synthesis that use the 9-fluorenylmethyloxycarbonyl (Fmoc) group for Nα-amino protection has created a need for compatible anchoring linkages and handles. In an effort to develop mild new methods for use in solid-phase peptide synthesis (SPPS), a new ferrocene containing linker or “handle”, the 1’1-ferrocenyl carboxaldehyde handle was designed, synthesized, characterized and tested. This linker is analogous to those commercially available and developed by Barany. The ferrocenyl amine linker(FAL) releases C-terminal peptide amides upon acidolysis. Since the FAL handle is acid labile it is compatible with Fmoc and Nα-dithiasuccinoyl …

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Atomic And Electronic Structure Of Bulk Intermetallic And Heteroepitaxially Grown Surface Alloys, Orhan Kizilkaya Jan 2003

Atomic And Electronic Structure Of Bulk Intermetallic And Heteroepitaxially Grown Surface Alloys, Orhan Kizilkaya

LSU Doctoral Dissertations

It has been well documented that the surfaces of solids may differ from their bulk counterpart. The symmetry that a bulk possesses is broken at the surface. Due to this broken symmetry in the reduced dimension of the surface, the energetic of the surface also differs from the bulk counterpart. Reconstruction, charge redistribution, and surface alloying are phenomena that minimize the surface free energy. Surface properties of scientifically and technologically important bimetallic systems are the main focus of this dissertation. Specifically, surfaces of bulk alloy or heteroepitaxially grown metal-on-metal systems have been investigated primarily with two indispensable surface techniques, scanning …

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Field Validation Of Bentazon Phytoremediation, Sajida Begum Jan 2003

Field Validation Of Bentazon Phytoremediation, Sajida Begum

LSU Master's Theses

Phytoremediation with black willow (Salix nigra) was conducted in 1996 by planting trees at a density of 2000 trees/hectare at BASF Corporation in a shallow groundwater plume containing low levels of bentazon. In this project, the roots, stems,and leaves of the black willow plants were extracted and analyzed to see if bentazon from the ground water was taken up by the plants. Different extraction procedures such as liquid-phase extraction and solid-phase extraction were compared. Final determination using different analytical techniques such as GC-MSD, GC-ECD, and HPLC with UV detection for the isolation and analysis of bentazon residues from the plant …

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Evaluation Of The Profiler As A Tool For Imrt Qa, Manuel Rodriguez Jan 2003

Evaluation Of The Profiler As A Tool For Imrt Qa, Manuel Rodriguez

LSU Master's Theses

The principal goal in this project is to determine if a one-dimensional diode array, the Profiler (Sun Nuclear Corporation), can be used as a tool for intensity modulated radiation therapy quality assurance (QA). A one-dimensional diode array can be used to measure dose and dose profiles for IMRT fields. IMRT fields for real cases at Mary Bird Perkins Cancer Center were used to test the Profiler model 1170 (Sun Nuclear Corporation). The main concern with the Profiler is that there is not central diode in the array. The absorbed dose displayed in the Profiler window is the average of the …

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Computer Assisted Eye Fungal Infection Diagnosis, Madhusudhanan Balasubramanian Jan 2003

Computer Assisted Eye Fungal Infection Diagnosis, Madhusudhanan Balasubramanian

LSU Master's Theses

In this thesis, an attempt has been made to assist the diagnosis of Fungal Keratitis, a fungal infection that occurs in the corneal layers of the eye, by identifying the region of infection in the corneal images using fractal-based features. Three features related to the fractal dimension of the surface of the image, when represented in a 3D using the pixel intensity measure, are used to identify these regions in the image. To reduce the computation complexity, Fisher linear discriminant (FLD) is used to reduce the 3D raw feature to 1D feature, while preserving feature values. Using the adaptive mixtures …

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Factors Affecting Participation In City Recycling Programs, Stacy Marie Lockhart Jan 2003

Factors Affecting Participation In City Recycling Programs, Stacy Marie Lockhart

LSU Master's Theses

Recycling consists of diverting or recovering materials from the solid waste stream that would otherwise end up returning to the environment as a potential source of pollution. These collected materials are then used as raw materials in the manufacture or assembly of a new product or package. Over the years the amount of municipal solid waste being generated per person has steadily increased. Waste disposal costs are also increasing, making recycling even more important. To address this issue cities are developing recycling policies or plans. The type of plan varies according to the area; as of this time there are …

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An Ecopath/Ecosim Analysis Of An Estuarine Food Web: Seasonal Energy Flow And Response To River-Flow Related Perturbations, Laura Lynette Althauser Jan 2003

An Ecopath/Ecosim Analysis Of An Estuarine Food Web: Seasonal Energy Flow And Response To River-Flow Related Perturbations, Laura Lynette Althauser

LSU Master's Theses

Estuaries are often the receiving basins for major river systems which makes them vulnerable to anthropogenic influences. I used Ecopath and Ecosim to investigate the structure of the Weeks Bay, Alabama, USA food web, and the responses of the food web to bottom-up perturbations. Four season-specific steady-state Ecopath models were developed and used to compare the production, biomass, consumption, biomass flows, and higher order indices of ecosystem functioning of the Weeks Bay food web under winter, spring, summer, and fall conditions. The season-specific Ecopath snapshots indicated that the structure of the Weeks Bay food web was resilient. Winter had the …

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