Physical Sciences and Mathematics Commons^™

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 …

Book Embeddings Of Graphs, Robin Leigh Blankenship

LSU Doctoral Dissertations

We use a structural theorem of Robertson and Seymour to show that for every minor-closed class of graphs, other than the class of all graphs, there is a number k such that every member of the class can be embedded in a book with k pages. Book embeddings of graphs with relation to surfaces, vertex extensions, clique-sums and r-rings are combined into a single book embedding of a graph in the minor-closed class. The effects of subdividing a complete graph and a complete bipartite graph with respect to book thickness are studied. We prove that if n ≥ 3, …

Massively Parallel Molecular Dynamics Simulations Of Crack-Front Dynamics And Morphology In Amorphous Nanostructured Silica, Cindy Lynn Rountree

LSU Doctoral Dissertations

Atomistic aspects of dynamic fracture in amorphous and nanostructured silica are herein studied via Molecular dynamics (MD) simulations, ranging from a million to 113 million atom system. The MD simulations were performed on massivelly parallel computers using highly efficient multi-resolution algorithms. Crack propagation in these systems is accompanied by nucleation and growth of nanometer scale cavities up to 20 nm ahead of the crack front. Cavities coalesce and merge with the advancing crack to cause mechanical failure. Recent AFM studies in silica glasses confirm this scenario of fracture [1]. The morphology of the fracture surfaces is studied by calculating the …

Solid-Phase Dna Sequencing Reactions Performed In Micro-Capillary Reactors And Solid-Phase Reversible Immobilization In Microfluidic Chips For Purification Of Dye-Labeled Dna Sequencing Fragments, Yichuan Xu

LSU Doctoral Dissertations

The research presented in this dissertation involves micro-capillary reactors for solid phase DNA sequencing, the identification of dye terminator sequencing fragments with time-resolved methods, and purification of dye-labeled DNA fragments using solid- phase reversible immobilization in microfluidic chips. Solid-phase micro-reactors have been prepared for DNA sequencing applications using slab gel electrophoresis. A PCR product was immobilized to the interior wall of a fused-silica capillary tube via a biotin-streptavidin linkage. Solid-phase sequencing was carried out in micro-capillary reactors using a four-lane, single color dye primer chemistry strategy. The read length was found to be 589 bases. The complementary DNA fragments generated …

Assessment Of The Acoustic Properties Of Common Tissue-Mimicking Test Phantoms, Jacinta Browne, K. Ramnarine, A. Watson, P. Hoskins

Articles

Ultrasound (US) test phantoms incorporating tissue-mimicking materials (TMMs) play an important role in the quality control (QC) and performance testing of US equipment. Three commercially available TMMs (ZerdineTM from CIRS Inc.; condensed-milk-based gel from Gammex RMI; urethane-rubber-based from ATS Labs) and a noncommercial agar-based TMM, were investigated. Acoustic properties were measured over the frequency range 2.25 to 15 MHz at a range of ambient temperatures (10 to 35°C). The acoustic velocity of the TMMs remained relatively constant with increasing frequency. Only the agar-based TMM had a linear increase of attenuation with frequency, with the other materials exhibiting nonlinear responses to …

How To Establish Successful Cooperative Student Learning Centers For Stem Courses, Ronald James Bieniek, Douglas R. Carroll, Cesar Mendoza, Oran Allan Pringle, Ekkehard Sinn, Kai-Tak Wan, Donald C. Wunsch

Physics Faculty Research & Creative Works

Students learn more if they are actively involved in the learning process, particularly in a cooperative manner. Several UMR faculty have operated course-based learning centers (LCs) as part of the campus-wide Learning Enhancement Across Disciplines (LEAD) Program of student learning assistance and enhancement. LCs are designed to assist large numbers of students in a cost- and time-efficient manner that promotes student engagement without requiring undue amounts of faculty time. Course instructors spend time in the open learning environment of the LC, in lieu of office hours, guiding students to master course material and skills in their evolution from novice to …

Control Of Transport Dynamics In Overlay Networks, Qishi Wu

LSU Doctoral Dissertations

Transport control is an important factor in the performance of Internet protocols, particularly in the next generation network applications involving computational steering, interactive visualization, instrument control, and transfer of large data sets. The widely deployed Transport Control Protocol is inadequate for these tasks due to its performance drawbacks. The purpose of this dissertation is to conduct a rigorous analytical study on the design and performance of transport protocols, and systematically develop a new class of protocols to overcome the limitations of current methods. Various sources of randomness exist in network performance measurements due to the stochastic nature of network traffic. …

Splitter Theorems For 3- And 4-Regular Graphs, Jinko Kanno

LSU Doctoral Dissertations

Let g be a class of graphs and ≤ be a graph containment relation. A splitter theorem for g under ≤ is a result that claims the existence of a set O of graph operations such that if G and H are in g and H≤G with G≠H, then there is a decreasing sequence of graphs from G to H, say G=G₀≥G₁≥G₂...G_t=H, all intermediate graphs are in g, and each G_i can be obtained from G_i-1 by applying a single …

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 …

The Ecology Of Two Estuarine-Dependent Tonguefishes, The Blackcheek Tonguefish (Symphurus Plagiusa) And The Offshore Tonguefish (S. Civitatium), In Coastal Louisiana, Theodore Scott Switzer

LSU Doctoral Dissertations

The pattern and process of wetland loss in coastal Louisiana has the potential to influence the distribution and abundance of fishes and macroinvertebrates that utilize inshore estuarine habitat as nurseries during their early life histories. Current management plans designed to stabilize marsh elevations, such as freshwater diversions, may also influence the distribution and abundance of estuarine-dependent nekton. Given the importance of nursery function of inshore estuaries in coastal Louisiana, it is of interest to explore the response of estuarine-dependent organisms to environmental gradients. To this end I examined the ecology of two sympatric tonguefishes, the blackcheek tonguefish (Symphurus plagiusa) and …

Machine Learning Techniques For Efficient Query Processing In Kowledge Base Systems, Kevin Paul Grant

LSU Doctoral Dissertations

In this dissertation we propose a new technique for efficient query processing in knowledge base systems. Query processing in knowledge base systems poses strong computational challenges because of the presence of combinatorial explosion. This arises because at any point during query processing there may be too many subqueries available for further exploration. Overcoming this difficulty requires effective mechanisms for choosing from among these subqueries good subqueries for further processing. Inspired by existing works on stochastic logic programs, compositional modeling and probabilistic heuristic estimates we create a new, nondeterministic method to accomplish the task of subquery selection for query processing. Specifically, …

Angle-Resolved Photoemission Study And Neutron Diffraction Measurements On Lasb2, Alice Acatrinei

LSU Doctoral Dissertations

LaSb₂ has recently been found to have unusual magnetoresistive properties despite the fact that neither La nor Sb are magnetic. The resistance is anisotropic, and at high magnetic fields presents an anomaly that might be a result of a charge density transition. The magnetoresistance is anisotropic and linear, and the resistivity presents high relative changes when a magnetic field is applied. Discovered in 1954, LaSb₂, as the rest of the light rare-earth diantimonides, was poorly studied. The anisotropic magnetic properties reported in 1998 by Bud'ko, Canfield and their collaborators make the series very interesting. A description of …

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 …

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 …

Nsea - Environmental Stewardship Intern, Alexandra Haase

College of the Environment Internship Reports

My responsibilities as a Stewardship Intern at NSEA revolved around prepping, setting up, and striking weekly work parties, teaching volunteers the tools and techniques used in river restoration, and educating community members about the significance of salmon as a keystone species in the Nooksack Watershed.

A Comparison Of Finfish Assemblages On Subtidal Oyster Shell (Cultched Oyster Lease) And Mud Bottom In Barataria Bay, Louisiana, John Plunket

LSU Master's Theses

Recent research suggests that oyster reefs provide unique three-dimensional hard bottom habitat for many fish species. Along the northern shore of the Gulf of Mexico, oyster shell bottoms are predominantly flat, subtidal and cultched, lacking the vertical relief and spatial heterogeneity provided by natural reefs. This study compared finfish assemblages, gut contents, and macroinvertebrate assemblages at subtidal oyster shell (cultched oyster lease) and mud bottoms in Barataria Bay, Louisiana. Three mud and three shell sites were sampled on seven dates from October 2001 to October 2002, using gill nets and substrate trays. Data from the gill nets were used to …

Gauss' Method Of Least Squares: An Historically-Based Introduction, Belinda B. Brand

LSU Master's Theses

This work presents Gauss' justification of the method of least squares, following the treatment given by Gauss himself in "Theoria Combinationis Observationum Erroribus Minimis Obnoxiae," where the main idea is to show that the least squares estimate is the unbiased linear estimate of minimum variance. (Actually, we present Gauss' argument both in his terminology and translated into matrix terminology.) We show how this contrasts with Gauss' earlier justfication in "Theoria Motus Corporum Coelestium" which was based on the assumption of a normal distribution of errors, and yielded the estimate of maximum likelihood. We present as a background the development from …

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.

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 …

The Salton Sea Wetlands: A Guidebook Of Curriculum Based Lessons, Etta Margo Ligman-Mccormick

Theses Digitization Project

Using Coachella Valley's Salton Sea ecosystem as a model, several multidisciplinary wetland activities for grades three to six were developed. A resource guide for educators is included.

A Live Collection Of A Pistolgrip From Nebraska, Steven C. Schainost

Nebraska Game and Parks Commission: Staff Research Publications

Freshwater mussels (Mollusca: Bivalvia: Unionidae) are one of Nebraska's more poorly known faunas. Studies have documented the presence of 31 species of which only 19 have been found either live or freshly dead. The remaining twelve species have only been found as weathered or subfossil shells, seven of which were considered to be extirpated including the pistolgrip (Tritogonia verrucosa). While a statewide survey never has been done there is distributional information available in several published papers and unpublished reports (Baxa 1981; Hoke 1983, 1994a, 1995, 1996, 1997; Roedel 1990; Lingle 1992; Freeman and Perkins 1992, 1997; Clausen and …

Spectral Functions Of The Falicov-Kimball Model With Electronic Ferroelectricity, Wei-Guo Yin, Wai-Ning Mei, Chun-Gang Duan, Hai-Qing Lin, John R. Hardy

John R. Hardy Papers

We calculate the angular resolved photoemission spectrum of the Falicov-Kimball model with electronic ferroelectricity where d- and f-electrons have different hoppings. In mix-valence regimes, the presence of strong scattering processes between d – f excitons and a hole, created by emission of an electron, leads to the formation of pseudospin polarons and novel electronic structures with bandwidth scaling with that of d – f excitons. Especially, in the two-dimensional case, we find that flat regions exist near the bottom of the quasiparticle band in a wide range of the d- and f-level energy difference.

Molecular Dynamics Simulation Of The Order-Disorder Phase Transition In Solid Nano2, Wei-Guo Yin, Chun-Gang Duan, Wai-Ning Mei, Jianjun Liu, R. W. Smith, John R. Hardy

John R. Hardy Papers

We present molecular dynamics simulations of solid NaNO₂ using pair potentials with the rigid-ion model. The crystal potential surface is calculated by using an a priori method which integrates the ab initio calculations with the Gordon-Kim electron gas theory. This approach is carefully examined by using different population analysis methods and comparing the intermolecular interactions resulting from this approach with those from the ab initio Hartree-Fock calculations. Our numerics show that the ferroelectric-paraelectric phase transition in solid NaNO₂ is triggered by rotation of the nitrite ions around the crystallographical c axis, in agreement with recent x-ray experiments [Gohda …

Mining Geology Of The Fire Clay Coal, Stephen F. Greb

Map and Chart--KGS

The Fire Clay (Hazard No. 4) coal is one of the leading producers in the Eastern Kentucky Coal Field, with more than 20 million short tons of annual production and 230 million short tons mined between 1976 and 1992, according to Kentucky Department of Mines and Minerals data. Regional thickness and resources of the coal are calculated in Greb and others (1999c) and Thacker and others (2000a, b).

Stratigraphically, the coal occurs in the middle part of the Hyden Formation of the Breathitt Group (Fig. 1), which was previously part of the Breathitt Formation (Chesnut, 1992). The coal occurs between …

The Computational Complexity Of Motion Planning, Jeff R.K. Hartline '01, Ran Libeskind-Hadas

All HMC Faculty Publications and Research

In this paper we show that a generalization of a popular motion planning puzzle called Lunar Lockout is computationally intractable. In particular, we show that the problem is PSPACE-complete. We begin with a review of NP-completeness and polynomial-time reductions, introduce the class PSPACE, and motivate the significance of PSPACE-complete problems. Afterwards, we prove that determining whether a given instance of a generalized Lunar Lockout puzzle is solvable is PSPACE-complete.

A Mathematical Model Of Immune Response To Tumor Invasion, Lisette De Pillis, Ami Radunskaya

All HMC Faculty Publications and Research

Recent experimental studies by Diefenbach et al. [1] have brought to light new information about how the immune system of the mouse responds to the presence of a tumor. In the Diefenbach studies, tumor cells are modified to express higher levels of immune stimulating NKG2D ligands. Experimental results show that sufficiently high levels of ligand expression create a significant barrier to tumor establishment in the mouse. Additionally, ligand transduced tumor cells stimulate protective immunity to tumor rechallenge. Based on the results of the Diefenbach experiments, we have developed a mathematical model of tumor growth to address some of the questions …

Australian Hackers And Ethics, Matthew Warren, William Hutchinson

Research outputs pre 2011

The aim of the paper is to look at the way hackers act and ways in which society can protect itself. The paper will show the current views and attitudes of hackers in an Australian context. The paper will also include a case study to show how a hacking incident can develop and how technology can be used to protect against hacking.

Phytoplankton Assemblage Structure And Primary Productivity Along 170 Degrees W In The South Pacific Ocean, Gr Ditullio, Me Greesey, Dr Jones, Kl Daly, L Campbell, Walker O. Smith Jr.

VIMS Articles

Phytoplankton pigments were measured using HPLC during non-ENSO conditions in mid-summer along a South Pacific transect from 67degreesS to the equator along 170degreesW. Highest concentrations of chlorophyll a (chl a) occurred in the Polar and the Subtropical Fronts (PF and STF, respectively) with concentrations exceeding 500 ng l(-1). In the STF, there was a distinct subsurface chl a maximum (SCM) at 40 m, which gradually deepened northward to 120 m in the Subtropical Convergence Zone. Northwards, the SCM shoaled to about 30 m in the Equatorial Zone (EZ). Relatively high concentrations of fucoxanthin and 19'-butanoyloxyfucoxanthin occurred in the nutrient-rich waters …

Comparison Of The Theoretical And Experimental Band Structure Of Poly(Vinylidene Fluoride) Crystal, Chun-Gang Duan, Wai-Ning Mei, J.R. Hardy, Stephen Ducharme, Jaewu Choi, Peter A. Dowben

Peter Dowben Publications

The electronic structure and band symmetries of the ferroelectric phase of poly (vinylidene fluoride) (PVDF) are studied by using the first-principles density-functional method. Our calculated results agree well with the angle-resolved photoemission experiments. We find that the PVDF crystal has an energy gap of about 6 eV at the Γ-point. Large dispersion of the valence band is found only along the chain direction, which is consistent with the quasi-one-dimensional nature of PVDF. In particular, the band symmetries of the valence states deduced theoretically are in good agreement with experiment. Finally, further investigations on the electronic structure of poly(trifluoroethylene) (PTrFE) reveal …

An Assessment Of Water Quality In Ensign Hollow, Clayton And Fayette Counties, In Northeast Iowa, Rick Klann, Jaime Platts

Journal of the Iowa Academy of Science: JIAS

Water quality and benthic invertebrates in the Ensign Hollow watershed, southwestern Clayton County and southeastern Fayette County, Iowa, were monitored from 2000 to 2001. Measurements of physical and chemical parameters of water quality, as well as analysis of benthic invertebrates, all indicated that streams of the Ensign Hollow watershed were exposed to slight organic pollution. Furthermore, the greatest threat to this watershed appeared to be sedimentation introduced through runoff.