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Feedback Linearizing Control Strategies For Chemical Engineering Applications., Michael James Kurtz Jan 1997

Feedback Linearizing Control Strategies For Chemical Engineering Applications., Michael James Kurtz

LSU Historical Dissertations and Theses

Two widely studied control techniques which compensate for process nonlinearities are feedback linearization (FBL) and nonlinear model predictive control (NMPC). Feedback linearization has a low computational requirement but provides no means to explicitly handle constraints which are important in the chemical process industry. Nonlinear model predictive control provides explicit constraint compensation but only at the expense of high computational requirements. Both techniques suffer from the need for full-state feedback and may have high sensitivities to disturbances. The main work of this dissertation is to eliminate some of the disadvantages associated with FBL techniques. The computation time associated with solving a …

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Toward Prescriptive Alternatives To Secondary School Suspensions: Risk Analysis Using An Epidemiologic Approach., Cynthia P. Morgan-D'Atrio Jan 1997

Toward Prescriptive Alternatives To Secondary School Suspensions: Risk Analysis Using An Epidemiologic Approach., Cynthia P. Morgan-D'Atrio

LSU Historical Dissertations and Theses

Data were collected from a large urban high school in order to investigate the characteristics of students who get suspended. Descriptive, epidemiologic analyses, and multivariate statistical analyses were used to investigate which, if any of several screening variables were most likely to predict secondary school suspensions for 9th grade students. Because multivariate statistics may be tedious for many to interpret, epidemiologic analyses were used in order to more easily disseminate study findings to readers and those within the school setting. For males, statistics were calculated for three groups of students: (1) males having more than one 9th grade suspension, (2) …

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Optimization Of Out-Of-Core Computations Using Chain Vectors, M. Kandemir, J. Ramanujam, A. Choudhary Jan 1997

Optimization Of Out-Of-Core Computations Using Chain Vectors, M. Kandemir, J. Ramanujam, A. Choudhary

Faculty Publications

Over the last decade, processor speed has become significantly higher than memory and disk speeds. Therefore, exploiting the memory hierarchy has emerged as a key problem in parallel computing. An out-of-core computation is one which operates on disk-resident data. This paper uses the concept of chain vectors for tiling out-of-core codes. The theory of chain vectors is discussed and extended, and their relation to reuse vectors is established. Then, chain vectors are used to optimize the tile size, shape, allocation and scheduling for out-of-core codes.

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Cellulose-Reinforced Composites And Srim And Rtm Modeling., Mohammad Fahrurrozi Jan 1997

Cellulose-Reinforced Composites And Srim And Rtm Modeling., Mohammad Fahrurrozi

LSU Historical Dissertations and Theses

Structural reaction injection molding (SRIM) cellulosic/polyurethane composites were prepared from various forms of cellulosic mats, and elastomeric polyurea-urethane (PUU) and rigid polyurethane (PU) formulations. Mats (woven and non-woven) prepared from different sources of fibers with lignin content ranging from zero (cotton) to at least 10% (sugar cane and kenaf fibers) performed comparably in PUU/cellulosic composites. Young's modulus and tensile strength of PUU/cellulosic composites were doubled with 5% and 7% fiber loading respectively. Young's modulus and tensile strength of PU/cellulosic composites were improved by 300% and 30%, respectively, with 7% fiber loading, whereas their bending moduli and strengths were improved up …

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Fluorescence Lifetime Discrimination Of Near-Infrared Dye-Labeled Oligonucleotide Fragments Separated By Capillary Gel Electrophoresis For Base-Calling Applications In Dna Sequencing., Benjamin Leighton Legendre Jr Jan 1997

Fluorescence Lifetime Discrimination Of Near-Infrared Dye-Labeled Oligonucleotide Fragments Separated By Capillary Gel Electrophoresis For Base-Calling Applications In Dna Sequencing., Benjamin Leighton Legendre Jr

LSU Historical Dissertations and Theses

The research presented in this dissertation involves the construction of a near-infrared time-correlated single photon counting system which utilizes a mode-locked Ti:sapphire or pulsed diode laser as the excitation source and single photon avalanche diode as the photodetector and the subsequent study of two simple algorithms, the Maximum Likelihood Estimator (MLE) and the Rapid Lifetime Determination (RLD) methods, for fluorescence lifetime determination. The purpose of this research is to aid in the development of a low cost, highly efficient, and high throughput device for DNA sequencing which utilizes near-IR fluorophores which have similar absorption and emission properties but possess unique …

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The Influence Of Violence Upon Academic Achievement Among African American First Time College Students., Diana F. Kelly Jan 1997

The Influence Of Violence Upon Academic Achievement Among African American First Time College Students., Diana F. Kelly

LSU Historical Dissertations and Theses

This study examined the relationship between early exposure to violence--both personal and community--and the later academic achievement of African American first time college students. The study incorporated several variables that were thought to impinge upon the academic achievement process. Specifically, those variables were divided into several groups: background factors (socioeconomic status, high school academic record, personal and community violence exposure), student characteristics (locus of control, educational aspirations and expectations), and university characteristics (campus safety, academic and social integration). Student achievement was measured by students' expected grade point average, as indicated on a student questionnaire. University administrators, professors, and researchers who …

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Academic Discipline, Mentoring, And The Career Commitment Of Women Faculty., Gloria Tara Nye Jan 1997

Academic Discipline, Mentoring, And The Career Commitment Of Women Faculty., Gloria Tara Nye

LSU Historical Dissertations and Theses

Women continue to be underrepresented as faculty at U.S. universities, especially in the physical sciences and engineering. The belief that only women can adequately serve as role models and mentors for other women may be a roadblock to progress for women in disciplines where they are underrepresented. This study of women faculty investigates how female career commitment is influenced by academic discipline and mentoring. The survey responses of sixty-six tenure-track women faculty were used to obtain data for both science or engineering and non-science or engineering academic disciplines at three public Ph.D. granting research universities. The women faculty in science …

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Syntheses, Separations, And Applications Of Water-Soluble Chiral Calixarenes., Yuling Zhang Jan 1997

Syntheses, Separations, And Applications Of Water-Soluble Chiral Calixarenes., Yuling Zhang

LSU Historical Dissertations and Theses

This dissertation focuses on the study of water-soluble calixarene derivatives as receptors for fluorescence probes and as chiral selectors. The synthesis of sulfonated calixarenes was first pursued and a method for the separation of sulfonated calixarenes (4), (6), (8) and the 4-hydroxylbenzene sulfonate monomer by capillary zone electrophoresis with direct UV absorbance detection is described. Fluorescence and absorption studies of water-soluble sulfonated calix(6)arene (SCX6) are reported. A red shift in the absorption spectrum and a change in the fluorescence spectrum of the calixarenes are observed upon an increase in pH from 2.0 to 13.0. The spectroscopic changes are attributed to …

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A Theory Of Cortical Neural Processing., David Timothy Young Jan 1997

A Theory Of Cortical Neural Processing., David Timothy Young

LSU Historical Dissertations and Theses

This dissertation puts forth an original theory of cortical neural processing that is unique in its view of the interplay of chaotic and stable oscillatory neurodynamics and is meant to stimulate new ideas in artificial neural network modeling. Our theory is the first to suggest two new purposes for chaotic neurodynamics: (i) as a natural means of representing the uncertainty in the outcome of performed tasks, such as memory retrieval or classification, and (ii) as an automatic way of producing an economic representation of distributed information. We developed new models, to better understand how the cerebral cortex processes information, which …

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The Preparation And Production Of Rapid Sequential Aiming Movements In Motor Control., Dongwon Yook Jan 1997

The Preparation And Production Of Rapid Sequential Aiming Movements In Motor Control., Dongwon Yook

LSU Historical Dissertations and Theses

Three experiments are reported that attempt to further our knowledge of the preparation and production of rapid sequential aiming movements. Specifically, these experiments examined possible reasons why in sequential aiming responses, the second movement segment (MT2) is consistently performed more slowly than first and third movement segments (MT1 and MT3). In the first experiment, participants struck 1, 2, or 3 targets in sequence without the benefit of visual feedback and without time stress to determine if MT2 is slowed due to a visually based on-line trajectory-correction process. The results showed that MT2 was not slower than MT1 under these condition. …

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A Study Of The Effect Of Energetic Flux Bombardment On Intensified Plasma-Assisted Processing., Albert Amatey Adjaottor Jan 1997

A Study Of The Effect Of Energetic Flux Bombardment On Intensified Plasma-Assisted Processing., Albert Amatey Adjaottor

LSU Historical Dissertations and Theses

An investigation of the plasma nitriding mechanism under intensified conditions (average particle energy up to 1200 eV) was carried out using a triode configuration. The significance of the different physical processes taking place during intensified plasma nitriding, such as sputtering, implantation, defect generation, redeposition and diffusion were investigated experimentally, while theoretical predictions were obtained by using the TRIM (transport of ions in matter) code. A titanium-base alloy was selected as the substrate material. Sputtering yield in an inert atmosphere was found to exhibit three regimes as a function of incoming particle energy. The low energy and high energy regimes were …

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A Double-Hurdle Expenditure Analysis Of Nonconsumptive Wildlife-Related Recreation., Yeong-Nain Chi Jan 1997

A Double-Hurdle Expenditure Analysis Of Nonconsumptive Wildlife-Related Recreation., Yeong-Nain Chi

LSU Historical Dissertations and Theses

This study utilized cross-sectional data obtained from the 1991 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation to analyze the expenditures and consumption of nonconsumptive wildlife related recreation in the Lower Mississippi Valley Ecosystem area. In the process of selecting an appropriate model most consistent with individuals' consumption behavior associated with nonconsumptive wildlife related recreation, the tobit model and the double-hurdle model for both the primary nonresidential and residential expenditure models were evaluated. Based on the Lagrange multiplier test and the likelihood ratio test results, the double-hurdle model fit the data much better than the tobit model. The hypothesis that …

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Magnetic Measurements On Superconductors And Heavy Fermions., Donavan Weslee Hall Jan 1997

Magnetic Measurements On Superconductors And Heavy Fermions., Donavan Weslee Hall

LSU Historical Dissertations and Theses

Magnetization and de Haas - van Alphen (dHvA) measurements have been made on the high temperature superconductor Ba$\sb{0.6}$K$\sb{0.4}$BiO$\sb3$ and the heavy fermion CeB$\sb6$. First ever observations of the dHvA effect in Ba$\sb{0.6}$K$\sb{0.4}$BiO$\sb3$ are reported. Two dHvA spectrometers (pulsed field and field modulation) were used to measure two samples. Four frequencies are found in the field modulation data with the 11.6 kT orbit in good agreement with band structure calculations. The three lowest frequencies were measured with the pulsed field spectrometer. All dHvA measurements were made in the superconducting mixed state. These measurements indicate that Ba$\sb{0.6}$K$\sb{0.4}$BiO$\sb3$ has a Fermi surface. Magnetization …

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The Effects Of The Louisiana Systemic Initiative Project On Two Rural School Districts In Louisiana., Tanya Maria Jones Jan 1997

The Effects Of The Louisiana Systemic Initiative Project On Two Rural School Districts In Louisiana., Tanya Maria Jones

LSU Historical Dissertations and Theses

This study provides a description and analysis of the effects of a mathematics reform initiative on classrooms in two rural communities. It describes the sites, details interactions that take place in the classroom, and enumerates teachers' perceptions of the change. A mixed methodology was used to support the findings. Qualitative data were collected through classroom observations and interviews and quantitative data were gathered through questionnaires. Quantitative results indicated that teachers who participate in the training have the opportunity to learn more about new teaching strategies in mathematics and are likely to change their teaching practices in mathematics. Findings reflected that …

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Development Of Thin Gold Film Thermal Sensors For Synchrotron X-Ray Exposure Diagnostics., Harish M. Manohara Jan 1997

Development Of Thin Gold Film Thermal Sensors For Synchrotron X-Ray Exposure Diagnostics., Harish M. Manohara

LSU Historical Dissertations and Theses

High aspect ratio lithography utilizes high intensity exposure sources, such as synchrotron storage rings, to deposit sufficient dose in the resist to produce a successful pattern transfer. Such highly powerful sources are known to cause undesirable thermal effects in the mask-resist-substrate system. Hence, the measurement of temperature of a mask-resist-substrate system during irradiation is an important exposure diagnostic feature. Deposition of a reasonably accurate dose in the resist is controlled by knowledge of the exposure source intensity. Periodic monitoring of the synchrotron radiation beam power and its spatial distribution at the exposure plane is necessary. In this research, diagnostic techniques …

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Negotiating Literacy Instruction: Pedagogical Perceptions Of Secondary Preservice Teachers., Julie Hill Lester Jan 1997

Negotiating Literacy Instruction: Pedagogical Perceptions Of Secondary Preservice Teachers., Julie Hill Lester

LSU Historical Dissertations and Theses

Secondary teachers face the challenge of planning instructional activities that combine their own subject knowledge with information from textbooks and other forms of text to help students learn content material. This study explores preservice teachers' perceptions regarding literacy instruction within the context of teaching and learning content material. The participants are senior secondary education students enrolled in a content area literacy course at a regional university in the southeast. Case studies are constructed for six preservice teachers representing different content areas. Qualitative data collection procedures included a questionnaire, guided journal entries, literacy autobiography, and personal interviews. Cross-case analysis was employed. …

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Feasibility Study On The Reduction Of Hydrostatic Pressure In A Deep-Water Riser Using A Gas-Lift Method., Clovis Antonio Lopes Jan 1997

Feasibility Study On The Reduction Of Hydrostatic Pressure In A Deep-Water Riser Using A Gas-Lift Method., Clovis Antonio Lopes

LSU Historical Dissertations and Theses

Recent successful exploration efforts in deep waters have heightened interest in developing oil and gas reservoirs on the continental slope. Leases have been obtained in water depths up to 10,000 ft with a requirement that they be drilled within the next decade. Use of current techniques to drill these leases will require extremely large floating drilling units and large diameter marine riser systems. This study presents the results of a feasibility study on the use of an automated gas-lift system for a marine riser that will maintain the hydrostatic pressure in the subsea well-head equal to that of the sea …

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The Use Of Secondarily Treated Wastewater Effluent For Forested Wetland Restoration In A Subsiding Coastal Zone., John M. Rybczyk Jan 1997

The Use Of Secondarily Treated Wastewater Effluent For Forested Wetland Restoration In A Subsiding Coastal Zone., John M. Rybczyk

LSU Historical Dissertations and Theses

Insufficient sedimentation, coupled with high rates of relative sea-level rise (RSLR), are two important factors contributing to wetland loss in coastal Louisiana. I hypothesized that adding nutrient rich, secondarily treated, wastewater effluent to subsiding coastal wetlands in Louisiana could promote vertical accretion in these systems through increased organic matter production and subsequent deposition, and allow accretion to keep pace with estimated rates of RSLR (subsidence plus eustatic sea-level rise). To test this hypothesis, I measured processes affecting wetland elevation including, organic matter decomposition, sediment accretion, aboveground primary production, and, plant tissue nutrient (N, P, K, Ca, Mg, Fe) concentrations, in …

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Pseudospin Transformation Of Physical Operators, A. L. Blokhin, C. Bahri, J. P. Draayer Dec 1996

Pseudospin Transformation Of Physical Operators, A. L. Blokhin, C. Bahri, J. P. Draayer

Faculty Publications

A procedure for applications of the pseudospin transformation within the framework of nuclear oscillator shell model is developed. It is valid for operators expressed in terms of single-particle variables and is based on permutation rules for special rotational invariants. The procedure is applied to a number of physical operators including several rotational scalars, the spin and orbital momenta, and the quadrupole moment. An algorithm for generating an approximation to the pseudospin transformation, which gives a simple and accurate expression for dominant parts of required transforms, is also given. The algebras associated with pseudospin transformations are discussed. © 1996 IOP Publishing …

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On The Matroids In Which All Hyperplanes Are Binary, S. R. Kingan, J. G. Oxley Nov 1996

On The Matroids In Which All Hyperplanes Are Binary, S. R. Kingan, J. G. Oxley

Faculty Publications

In this paper, it is shown that, for a minor-closed class ℳ of matroids, the class of matroids in which every hyperplane is in ℳ is itself minor-closed and has, as its excluded minors, the matroids U1,1 ⊕ N such that N is an excluded minor for ℳ. This result is applied to the class of matroids of the title, and several alternative characterizations of the last class are given.

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Theory And Operation Of Continuous Flow Systems For The Study Of Benthic-Pelagic Coupling, Tina Miller-Way, Robert R. Twilley Sep 1996

Theory And Operation Of Continuous Flow Systems For The Study Of Benthic-Pelagic Coupling, Tina Miller-Way, Robert R. Twilley

Faculty Publications

Continuous flow systems have not been widely used in the study of benthic-pelagic coupling in marine systems. This paper discusses the theoretical and practical use of continuous flow sysrems for the study of benthic exchange processes and presents the results of experiments which compared continuous flow (open) and closed (batch) systems and investigated the sensitivity of exchange rates to residence times in a continuous flow system. Continuous flow systems minimize the problem of environmental dependency of benthic-pelagic exchange rates by maintaining initial experimental conditions throughout an incubation. However, the selection of a supply rate (i.e. residence time) is critical in …

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Pre-Asymptotic Expansions, A. L. Durán, R. Estrada, R. P. Kanwal Sep 1996

Pre-Asymptotic Expansions, A. L. Durán, R. Estrada, R. P. Kanwal

Faculty Publications

We introduce the concepts of pre-asymptotic schemes and pre-asymptotic expansions to study the divergent series that formally are solutions of various types of equations. © 1996 Academic Press, Inc.

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A Problem Set In Conditional Probability Using Martingales With A Derivation Of The Gambler’S Ruin Formula, Michael Everett Theriot Jr Jul 1996

A Problem Set In Conditional Probability Using Martingales With A Derivation Of The Gambler’S Ruin Formula, Michael Everett Theriot Jr

Honors Capstones

No abstract provided.

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Effects Of Climate Change On Hypoxia In Coastal Waters: A Doubled Co2 Scenario For The Northern Gulf Of Mexico, Dubravko Justic, Nancy N. Rabalais, R. Eugene Turner Jul 1996

Effects Of Climate Change On Hypoxia In Coastal Waters: A Doubled Co2 Scenario For The Northern Gulf Of Mexico, Dubravko Justic, Nancy N. Rabalais, R. Eugene Turner

Faculty Publications

Projections of general circulation models suggest that freshwater discharge from the Mississippi River to the coastal ocean will increase 20% if atmospheric CO2 concentration doubles. This result is likely to affect water column stability, surface productivity, and global oxygen cycling in the northern Gulf of Mexico, which is the site of the largest (up to 16,500 km2) and most severe hypoxic zone (liter‒1) in the western Atlantic Ocean. We use a coupled physical-biological two-box model to investigate potential effects of climate change on seasonal oxygen cycling and hypoxia in river-dominated coastal waters. The model was developed and calibrated using comprehensive …

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Nutrient Changes In The Mississippi River And System Responses On The Adjacent Continental Shelf, Nancy N. Rabalais, R. Eugene Turner, Dubravko Justic, Quay Dortch, William J. Wiseman, Barun Sen Gupta Jun 1996

Nutrient Changes In The Mississippi River And System Responses On The Adjacent Continental Shelf, Nancy N. Rabalais, R. Eugene Turner, Dubravko Justic, Quay Dortch, William J. Wiseman, Barun Sen Gupta

Faculty Publications

The Mississippi River system ranks among the world's top 10 rivers in freshwater and sediment inputs to the coastal ocean. The river contributes 90% of the freshwater loading to the Gulf of Mexico, and terminates amidst one of the United States' most productive fisheries regions and the location of the largest zone of hypoxia, in the western Atlantic Ocean. Significant increases in riverine nutrient concentrations and loadings of nitrate and phosphorus and decreases in silicate have occurred this century, and have accelerated since 1950. Consequently, major alterations have occurred in the probable nutrient limitation and overall stoichiometric nutrient balance in …

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The Effects Of Free Fatty Acids And Tocopherol On Membrane Order And Antioxidant Activity, Gina Michelle Pineda Apr 1996

The Effects Of Free Fatty Acids And Tocopherol On Membrane Order And Antioxidant Activity, Gina Michelle Pineda

Honors Capstones

No abstract provided.

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On Tree-Partitions Of Graphs, Guoli Ding, Bogdan Oporowski Feb 1996

On Tree-Partitions Of Graphs, Guoli Ding, Bogdan Oporowski

Faculty Publications

A graph G admits a tree-partition of width k if its vertex set can be partitioned into sets of size at most k so that the graph obtained by identifying the vertices in each set of the partition, and then deleting loops and parallel edges, is a forest. In the paper, we characterize the classes of graphs (finite and infinite) of bounded tree-partition-width in terms of excluded topological minors.

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Towards A Loop Representation For Quantum Canonical Supergravity, Daniel Armand-Ugon, Rodolfo Gambini, Octavio Obregón, Jorge Pullin Feb 1996

Towards A Loop Representation For Quantum Canonical Supergravity, Daniel Armand-Ugon, Rodolfo Gambini, Octavio Obregón, Jorge Pullin

Faculty Publications

We study several aspects of the canonical quantization of supergravity in terms of the Ashtekar variables. We cast the theory in terms of a GSU (2) connection and we introduce a loop representation. The solution space is similar to the loop representation of ordinary gravity, the main difference being the form of the Mandelstam identities. Physical states are in general given by knot invariants that are compatible with the GSU/(2) Mandelstam identities. There is an explicit solution to all the quantum constraint equations connected with the Chern-Simons form, which coincides exactly with the Dubrovnik version of the Kauffman polynomial. This …

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Spectrum Generating Operators And Intertwining Operators For Representations Induced From A Maximal Parabolic Subgroup, Thomas Branson, Gestur Ólafsson, Bent Ørsted Jan 1996

Spectrum Generating Operators And Intertwining Operators For Representations Induced From A Maximal Parabolic Subgroup, Thomas Branson, Gestur Ólafsson, Bent Ørsted

Faculty Publications

We present a new method of calculating intertwining operators between principal series representations of semisimple Lie groups G. Working in the compact realization we find the eigenvalues of the operators on the K-types, and give several examples. Among the advantages of our method is its applicability to bundle-valued cases. © 1996 Academic Press, Inc.

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Gumbo Yearbook, Class Of 1996, Louisiana State University And Agricultural And Mechanical College Jan 1996

Gumbo Yearbook, Class Of 1996, Louisiana State University And Agricultural And Mechanical College

Gumbo Yearbook

The Gumbo yearbook chronicles the entire academic year at LSU. In words and especially photos, the Gumbo shows the people, places, and events that make each year unique. In addition to formal portraits of schools and departments, the book contains hundreds of snapshots of students with their friends and dozens of pages showcasing organizations.

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