Digital Commons Network^™

New Learning And Control Algorithms For Neural Networks., Chung Hwa Youn

LSU Historical Dissertations and Theses

Neural networks offer distributed processing power, error correcting capability and structural simplicity of the basic computing element. Neural networks have been found to be attractive for applications such as associative memory, robotics, image processing, speech understanding and optimization. Neural networks are self-adaptive systems that try to configure themselves to store new information. This dissertation investigates two approaches to improve performance: better learning and supervisory control. A new learning algorithm called the Correlation Continuous Unlearning (CCU) algorithm is presented. It is based on the idea of removing undesirable information that is encountered during the learning period. The control methods proposed in …

Real-Time Effective Stress Evaluation In Shales: Pore Pressure And Permeability Estimation., Jean-Louis Jerome Alixant

LSU Historical Dissertations and Theses

In this dissertation, a general method to determine the vertical effective stress in shales while drilling is developed. The concept is applied to the development of a model restricted to sodium smectitic shales, which are interpreted using Measurement-While-Drilling (MWD) resistivity data. Effective stress is introduced as the key parameter in the evaluation of petrophysical properties of shales, which provides a wide range of applications to the method. The model comprises two interpretation modules: an electrical module converts shale resistivity into porosity using a new formation factor relationship adapted from previous work, and a mechanical module relates porosity to void ratio …

Studies On The Agrobacterium Mediated Transformation Of Potato (Solanum Tuberosum L.) And Tobacco (Nicotiana Tabacum L.) With Antibacterial And High Essential Amino Acids Encoding Genes., Mehmet Selim Cetiner

LSU Historical Dissertations and Theses

Tuber disks from four cultivars of Solanum tuberosum L. were cultured on a Murashige and Skoog medium supplemented with B5 vitamins, 3.0% sucrose, 0.7% phytagar and ratios of indole-3-actyl-aspartic acid (IAAa) and zeatin riboside (ZR). No shoots were regenerated from Red LaSoda. Russet Burbank, Desiree, and LaBelle tuber disks produced shoots over a range of IAAa and ZR ratios. The greatest number of shoots was regenerated from Russet Burbank at 1 $\mu$M IAAa and 8 $\mu$M ZR. Different potato cultivars were also tested for their responses to Agrobacterium infections. Growth stage of the bacterial cultures and exposure duration of tuber …

An Anisotropic Finite Plasticity Model For Continuum Damage Mechanics., Peter Issa Kattan

LSU Historical Dissertations and Theses

A constitutive model is formulated for anisotropic continuum damage mechanics using first elasticity and then finite strain plasticity. The formulation is given in spatial coordinates (Eulerian reference frame) and incorporates both isotropic and kinematic hardening. The von Mises yield criterion is modified to include the effects of damage through the use of the hypothesis of elastic energy equivalence. A modified elasto-plastic stiffness tensor that includes the effects of damage is derived within the framework of the proposed model. The damage variable used represents average material degradation which reflects the various types of damage at the microscale level like nucleation and …

Natural Convection Above Heated Inclined Surfaces., John Anthony King

LSU Historical Dissertations and Theses

Motivated by a need to assess pollutant transport by upslope flows, an investigation has been conducted into the fundamentals of natural convection flow over inclined surfaces. Particular attention was focused on the influence of ambient fluid stability. Field studies were performed using tracer gas releases into the upslope flow over a Southern California mountain range. The field studies served to reveal the presence of a split slope flow recirculation and demonstrated the impact of this recirculation on the transport of pollutants from a valley. In order to pursue a controlled investigation of the phenomena found in the field work, a …

Development And Field Applications Of Shaly Sand Petrophysical Models., Milton Noel Lau

LSU Historical Dissertations and Theses

A new, theoretically derived model expressing shaly sand conductivity is presented. The proposed model is based on dual water and cation exchange capacity concepts. The new model is based on the Waxman and Smits concept of supplementing the water conductivity with a clay counterions conductivity. The model also utilizes the dual water theory, which relates each conductivity term to a particular type of water, each occupying a specific volume of the total pore space. The proposed model, however, assumes that the counterion conductivity can be represented by a hypothetical electrolyte. The properties of this electrolyte were derived from electrochemical and …

Geometric Modeling And Recognition Of Elongated Regions In Images., Charles Anthony Lipari Ii

LSU Historical Dissertations and Theses

The goal of this research is the recovery of elongated shapes from patterns of local features extracted from images. A generic geometric model-based approach is developed based on general concepts of 2-d form and structure. This is an intermediate-level analysis that is computed from groupings and decompositions of related low-level features. Axial representations are used to describe the shapes of image objects having the property of elongatedness. Curve-fitting is shown to compute axial sequences of the points in an elongated cluster. Script-clustering is performed about a parametric smooth curve to extract elongated partitions of the data incorporating constraints of point …

Fine Scale Velocity Measurements In A Turbulent Jet In A Confined Crossflow., Julie Ann Mathis

LSU Historical Dissertations and Theses

Measurements of the fine scale velocity field are made for a turbulent jet in a confined crossflow. With a crossflow velocity of 10.0 m/sec, jet-to-crossflow velocity ratios of 1, 2 and 4 are examined. Velocity measurements are obtained by laser velocimetry. The velocimetry system consists of a 15mW laser with a fringe mode optics setup, operated in the backscatter mode. Signal processing is accomplished with a tracker processer. At each measuring location, 28,400 velocity readings are obtained at a sampling frequency of 38,460 sec$\sp{-1}$. Calculations include construction of autocorrelation functions, Kolmogorov-normalized energy spectra and their moments, skewness and flatness of …

Wave Height Changes And Mass Transport On Tague Reef, A Caribbean Reef, North Coast Of St. Croix, U.S. Virgin Islands., Alexis Lugo-Fernandez

LSU Historical Dissertations and Theses

This study of wave and current transformations across a modern coral reef was conducted on Tague Reef, St. Croix (U.S.V.I.), during late March and early April 1987. The project objective was to improve our understanding of the magnitudes, frequencies, and spatial and temporal variations of waves and currents as they interact with a modern reef. Data were collected in 4 experiments over a 2-week period. During the experiments, atmospheric and sea state conditions were typical of Caribbean-Atlantic trade wind dominated areas. Results verify that infragravity waves of 27.7 min period and diurnal tides modulated high frequency wave and current processes. …

Constitutive Equations For Large Deformation, Rate-Dependent Plasticity For Metal Alloys., Louay Nadhim Mohammad

LSU Historical Dissertations and Theses

A system of constitutive equations is proposed that describes the viscoplastic behavior of a class of metal alloys when subjected to large deformations. The model is purely elastic before the plastic state is reached, and becomes elastic/viscoplastic after the plastic state has been exceeded. Three main assumptions are made with regard to the strain-rate dependency in the proposed formulation. The inelastic strain rate tensor is assumed to be normal to each point of the rate dependent convex yield surface. The initial yield stress obtained from uniaxial tests is assumed to be dependent on the rate of strain loading. Finally, the …

The Capacity Of Artificial Neural Networks Using The Delta Rule., Donald Louis Prados

LSU Historical Dissertations and Theses

Over the past several years, several papers have been published on the capacity of Hopfield neural networks. It has been shown that, using the Hebbian rule, the capacity of the Hopfield model is approximately N/4logN. The number of patterns one can store in a neural network, however, can be greatly increased by using learning algorithms other than the Hebbian rule such as the delta rule. The motivation behind this dissertation is to study, both analytically and experimentally, the information capacity of various neural network models using a modified version of the delta-rule algorithm. This modified version of the delta-rule algorithm …

Effects Of Genetic Traits On Nonlint Trash And Nep Content Of Cotton, Gossypium Hirsutum L., Ricardo Gabriel Novick

LSU Historical Dissertations and Theses

Gin induced lint quality problems (neps, short fiber content, seed-coat fragments and reductions in lint turnout) need the consideration of the entire cotton production system. Genetic traits could help reduce seed-cotton trash and/or improve cleanability at the gin. Twelve near-isolines involving four leaf shapes (okra, semi-okra, super-okra and normal), two bract types (frego and normal), two leaf-pubescence levels (semi-smoothness and hairy) and certain trait combinations were grown during 1985, 1986, and 1987 at three locations in Louisiana (Alexandria, Bossier City, and St. Joseph), and harvested with a spindle-picker. Seedcotton samples were ginned on a cut-down version of a commercial gin …

A Total Lagrangian Finite Element Analysis For Metal Forming With Application To Metal Extrusion., Mehrdad Foroozesh

LSU Historical Dissertations and Theses

A detailed formulation for finite element analysis of metal forming problems is carried out in this work. It incorporates every aspect of the analysis, including the iterative solution procedures for geometric and material non-linearities, implementation of the material model, and formulation of curved contact boundaries. The finite element formulation is based on a Total Lagrangian approach which by-passes the use of the Jaumann stress rate tensor commonly used in the Updated Lagrangian formulation. The yield model used is of the von Mises type with both kinematic and isotropic hardening and is formulated in the Eulerian space. This model is then …

Non-Newtonian Fluid Flow In Eccentric Annuli And Its Application To Petroleum Engineering Problems., Mustafa Haciislamoglu

LSU Historical Dissertations and Theses

The fluid flow in the annular gap in oilwells is a complex problem. The geometry of the annulus is customarily simplified to concentric annular flow. In this study, a fluid flow model is developed allowing annulus to be eccentric: inner pipe located anywhere in the annulus. Thus, a more realistic representation of the actual geometry is obtained. An equation of motion that defines flow of non-Newtonian fluids in eccentric annuli is derived. A numerical solution of this equation is presented. The velocity profiles, the viscosity profiles, and the flow rate vs frictional pressure loss gradient relationship are calculated for varying …

Harmonic Measurement And Reduction In Power Systems., Rutisurhata Kurniawan Hartana

LSU Historical Dissertations and Theses

Harmonic voltages and currents are created by nonlinear loads in power systems. These harmonics can cause serious problems to the energy suppliers (utility companies) and energy users (consumers). This dissertation presents new techniques for harmonic measurement and the accompanying problem, harmonic reduction. To reduce harmonics, the location and magnitude of harmonic sources must be known a priori. However, to measure and monitor harmonic sources requires specialized instrumentation that is not generally permanently installed at most buses. In this study, a method is developed to use neural networks in conjunction with state estimation for monitoring and estimating harmonic sources with only …

An Experimental And Computational Investigation Of Turbulent Jet Impingement In A Confined Crossflow., Keun Sun Chang

LSU Historical Dissertations and Theses

An experimental and computational investigation is made for the turbulent flow field generated by a jet discharging transversely into a confined moving stream. For jet to cross flow mean velocity ratios (R) equal to 2 and 4, measurements are made using a laser-Doppler velocimeter (LDV) in conjunction with a tracker processor. Quantities measured include mean velocities, turbulence intensities, turbulent shear stress, and dissipation rates of the turbulent kinetic energy. The jet flow Reynolds numbers investigated are 1.5 $\times$ 10$\sp4$ for R = 2 and 3.0 $\times$ 10$\sp4$ for R = 4. The structured nature of the turbulent flow field is …

From Forest, Stream, And Sea: Aspects Of Self-Sufficiency In The Nineteenth Century Louisiana Diet. (Volumes I And Ii)., James Patrick Whelan Jr

LSU Historical Dissertations and Theses

Studies of foodstuff self-sufficiency in the antebellum South have shown that during the middle third of the nineteenth century, as represented by the census years 1840, 1850 and 1860, certain regions of Louisiana suffered from meat production deficits. It has been assumed by most interested scholars that these deficits were overcome by importing pork and beef from the midwest or Upper South. Other possible sources of meat supplements that have not been generally considered are the wild game and fishery resources of the state. Hunting and fishing have long traditions as important activities in the South in general and in …

Photochemical Vapor Deposition Of Gallium-Arsenide Utilizing Ultraviolet Radiation., David Paul Norton

LSU Historical Dissertations and Theses

Photochemical means have been utilized to deposit arsenic, gallium and gallium arsenide thin films in an attempt to achieve deposition of gallium arsenide at substrate temperatures lower than those utilized in conventional organometallic chemical vapor deposition. Photolysis, Hg-photosensitization and light-driven pyrolysis have been utilized to obtain thin films on quartz, fused silica, gallium arsenide and silicon substrates. Triethylgallium and arsine served as the reactants with a low pressure Hg lamp, a high pressure Hg-Xe arc lamp and an ArF excimer laser serving as the ultraviolet radiation sources. Deposition of arsenic and gallium arsenide thin films on quartz was investigated utilizing …

Optimal Design And Control Of Distribution System Capacitors., Nugroho Iwan Santoso

LSU Historical Dissertations and Theses

The rapidly escalating costs of generation and transmission facilities as well as energy production have focussed attention on the need to optimize system capacity release and energy losses. The problem is generally solved by controlling the voltage or reactive power which also has a pivotal role within the distribution automatization schemes. A review of reactive power compensators and methodologies in designing and controlling distribution capacitors is given. In the presence of voltage source harmonics, a local load reactive power compensation method, cost-constrained power factor optimization using an LC compensator, is discussed. A new methodology based on a piecewise method for …

Modeling Wetland Loss In Coastal Louisiana: Geology, Geography, And Human Modifications, James H. Cowan Jr., R. Eugene Turner

Faculty Publications

Habitat change in coastal Louisiana from 1955/6 to 1978 was analyzed to determine the influence of geological and man-made changes on landscape patterns within 7.5 min quadrangle maps. Three quantitative analyses were used: principal components analysis, multiple regression analysis, and cluster analysis.

Regional differences in land loss rates reflect variations in geology and the deltaic growth/decay cycles, man-induced changes in hydrology (principally canal dredging and spoil banking), and land-use changes (principally urbanization and agricultural expansion). The coastal zone is not homogeneous with respect to these variables and the interaction between causal factors leading to wetland loss is therefore locally variable …

Louisiana Agriculture Magazine, Fall 1988, Lsu Agricultural Experiment Station

Louisiana Agriculture

No abstract provided.

Louisiana Agriculture Magazine, Summer 1988, Lsu Agricultural Experiment Station

Louisiana Agriculture

No abstract provided.

Marsh Management Plans In Practice: Do They Work In Coastal Louisiana, Usa?, James H. Cowan Jr., R. Eugene Turner, Donald R. Cahoon

Faculty Publications

Louisiana's coastal wetlands represent about 41% of the nation's total and are extensively managed for fish, fur, and waterfowl. Marsh management plans (MMPs) are currently used to avoid potential user conflicts and are believed to be a best management practice for specific management goals. In this article, we define MMPs and examine their variety, history, impacts, and future.

A MMP is an organized written plan submitted to state and federal permitting agencies for approval and whose purpose is to regulate wetland habitat quantity and quality (control land loss and enhance productivity). MMPs are usually implemented by making structural modifications in …

Cenobium 1988, Louisiana State University And Agricultural And Mechanical College, School Of Veterinary Medicine, Rosmarie Eger

Cenobium Yearbook

Cenobium began publication in 1977 and continued through 1990. Produced by students, the yearbooks are a chronicle of the daily life and the special events experienced by veterinary students at the LSU School of Veterinary Medicine.

Characterization Of The Pulpwood Procurement Environment Of Northwest Louisiana With A Geographic Information System., Richard William Brinker

LSU Historical Dissertations and Theses

An analysis of the pulpwood procurement environment was made to describe and model forest land area, ownership patterns, timber production, forest inventory, and the transportation network of 13 parishes in the northwest region of Louisiana. Pulpwood delivered to a pulpmill accounts for approximately 50 percent of pulp production costs. The cost of delivered pulpwood is a function of the mode of transportation, distance from the mill, competition for stumpage, and quality of the transportation network. A data base is developed from wood usage requirements, pulpmill and wood concentration yard locations, location of forested areas and their relative volumes. Areas of …

Prediction Of Methane Solubility In Geopressured Brine Solutions By Application Of Perturbation Theory., Yangtzu Chao

LSU Historical Dissertations and Theses

The ability to predict methane solubility in underground reservoirs is essential to eventual exploitation of geothermal-geopressured reservoirs as an alternate energy source. In this study, second-order Leonard-Barker-Henderson perturbation theory was applied to brine solutions containing H$\sb2$O, CH$\sb4$, C$\sb2$H$\sb6$, CO$\sb2$, and NaCl to develop a fundamentally-based thermodynamic approach to handle more effectively the broad temperature and pressure ranges encountered in underground reservoirs, and to include the effect of the presence of various salts and other gases on methane solubility. The apparent ideal solution fugacity, f$\sbsp{i}{o\sp\prime}$, for each solute gas is proposed and developed through perturbation theory as a direct measure of …

Natural And Artificial Regeneration Of Baldcypress (Taxodium Distichum (L.) Rich.) In The Barataria And Lake Verret Basins Of Louisiana., William Henry Conner

LSU Historical Dissertations and Theses

Louisiana contains the largest volume of baldcypress (Taxodium distichum (L.) Rich.) timber in the United States, with 70% of the volume located in the south central part of the state. Baldcypress regeneration was studied in the Barataria and Verret Basins during 1982-1987. Overall, natural regeneration was poor in both basins. There was some recruitment during the dry years 1984 and 1986 but these seedlings did not grow tall enough to survive subsequent flooding. Coppice regeneration in logged areas was excellent after logging, but a majority of the sprouts died in succeeding years. In three projects where baldcypress seedlings were planted …

High Temperature Coal-Gas Desulfurization: Kinetic Evaluation Of A Zinc Ferrite Sorbent., Gary D. Focht

LSU Historical Dissertations and Theses

Thermogravimetric techniques were used to monitor the weight of cylindrical zinc ferrite extrudes in order to examine the sulfidation and regeneration kinetics. The reaction of zinc ferrite with H$\sb2$S (sulfidation) was studied over a temperature range of 573-973 K in gas streams containing 0.6-3 mol% hydrogen sulfide. Reduced zinc ferrite, ZnO plus Fe$\sb3$O$\sb4$, is capable of complete sulfidation from 873-973 K except at conditions where the iron oxide in the sorbent is reduced to FeO, in which case sulfidation does not go to completion. The sulfidation reaction is controlled by internal diffusion and mass transfer from the bulk gas phase …

Minimum Time Motion Of A Robotic Manipulator., Heon Hwang

LSU Historical Dissertations and Theses

This dissertation treats the modeling, analysis, and trajectory control of a robotic manipulator to execute specified point-to-point tasks. The relative coordinate representation of kinematic and dynamic variables is defined using vectors and matrices based on coordinate transformations. A kinematic modeling of a manipulator is performed using Denavit-Hartenberg link parameters. For given end-effector information (location and orientation), a stable and efficient iterative numerical algorithm for a joint solution is developed. A modified general Gauss elimination and a direct minimum search are combined with other refinements to yield fast convergency and stable results. This algorithm can be used as a routine solution …

Application Of Entropy Theory To Multivariate Hydrologic Analysis. (Volumes I And Ii)., Predrag Felix Krstanovic

LSU Historical Dissertations and Theses

This dissertation discusses the multivariate hydrologic analysis by the entropy theory. It is divided into two major parts. The first part (Volume I) examines hydrologic frequency analysis, specifically rainfall-runoff modeling and the design of rainfall networks. The second part (Volume II) develops two flood forecasting models: the univariate streamflow model, and the bivariate rainfall-runoff model. The hydrologic frequency analysis focuses on three topics: multivariate normal distribution, multivariate exponential distribution and multivariate exponential distribution and multivariate mixed distributions. Many forms of univariate, bivariate and multivariate normal distributions are derived by using the principle of maximum entropy (POME), emphasizing the serial dependency …