Physical Sciences and Mathematics Commons^™

Where Are The Women Geoscience Professors?, Mary Anne Holmes, Suzanne O'Connel

Department of Earth and Atmospheric Sciences: Faculty Publications

Compiles an extensive set of data on the status of women in the geosciences, identifying successful strategies for increasing diversity as well as obstacles that hinder efforts. The lessons learned and best practices that arise from this report will help geoscientists continue to increase the gender diversity of their community. Some of these lessons also provide insight into ways to improve the racial and ethnic diversity of the geosciences.

Climate Effects On Corn Yield In Missour, Q. Steven Hu, Gregory Buyanovsky

Department of Earth and Atmospheric Sciences: Faculty Publications

Understanding climate effects on crop yield has been a continuous endeavor aiming at improving farming technology and management strategy, minimizing negative climate effects, and maximizing positive climate effects on yield. Many studies have examined climate effects on corn yield in different regions of the United States. However, most of those studies used yield and climate records that were shorter than 10 years and were for different years and localities. Although results of those studies showed various influences of climate on corn yield, they could be time specific and have been difficult to use for deriving a comprehensive understanding of climate …

Intercontinental Migration Of Large Mammalian Carnivores: Earliest Occurrence Of The Old World Beardog Amphicyon (Carnivora, Amphicyonidae) In North America, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

North American amphicyonid carnivorans are prominent members of the mid-Cenozoic terrestrial carnivore community during the late Eocene to late Miocene (Duchesnean to Clarendonian). Species range in size from <5 kg to >200 kg. Among the largest amphicyonids are Old and New World species of the genus Amphicyon: A. giganteus in Europe (18–~15? Ma) and Africa, A. ingens in North America (15.9–~14.2 Ma). Amphicyon first appears in the Oligocene of western Europe, surviving there until the late Miocene. Migration to Africa and North America takes place in the early Miocene. The genus occurs in the Arrisdrift fauna (Namibia) of southwest Africa, indicating migration south …

Diurnal Variation In The Basal Emission Rate Of Isoprene, Jennifer L. Funk, Clive G. Jones, Christine J. Baker, Heather M. Fuller, Christian P. Giardina, Manuel T. Lerdau

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Isoprene is emitted from numerous plant species and profoundly influences tropospheric chemistry. Due to the short lifetime of isoprene in the atmosphere, developing an understanding of emission patterns at small time scales is essential for modeling regional atmospheric chemistry processes. Previous studies suggest that diurnal fluctuations in isoprene emission may be substantial, leading to inaccuracies in emission estimates at larger scales. We examined diurnal patterns in the basal emission rate of isoprene in red oak (Quercus rubra), eastern cottonwood (Populus deltoides), and eucalyptus (Eucalyptus saligna) and the influence of light and temperature on the magnitude of these diurnal patterns. Maximum …

On The Existence And Stability Of Liquid Water On The Martian Surface, Justin Thompson

Inquiry: The University of Arkansas Undergraduate Research Journal

Present-day Mars is thought to be a frozen desert on which liquid water is not likely to be found. The prevailing assumption has been that due to average temperatures below 273 K and atmospheric pressures at or below water's triple-point vapor pressure of 6.1 mbar, the existence of liquid water as an equilibrium phase at or near the surface is impossible at the present epoch. However, there is substantial evidence that liquid water has existed in the past and may presently still exist on or directly below the Martian surface. I conducted simulation experiments in the Andromeda planetary environmental chamber …

Algorithmic Composition In Contrasting Music Styles, Tristan Mcauley, Philip Hingston

Research outputs pre 2011

The aim of this research was to automate the composition of convincingly “real” music in specific musical genres. By “real” music we mean music which is not obviously “machine generated”, is recognizable as being of the selected genre, is perceived as aesthetically pleasing, and is usable in a commercial context. To achieve this goal, various computational techniques were used, including genetic algorithms and finite state automata. The process involves an original, top down approach and a bottom up approach based on previous studies. Student musicians have objectively assessed the resulting compositions.

Bacterioplankton Distribution And Production In The Bathypelagic Ocean: Directly Coupled To Particulate Organic Carbon Export?, Da Hansell, Hw Ducklow

VIMS Articles

A recently published evaluation of bacterioplankton abundance and productivity in the bathypelagic North Pacific suggests that these properties are generally coupled with particulate organic carbon (POC) fluxes. In that analysis, bacterial biomass and productivity were several-fold greater in subarctic than subtropical waters, consistent with the basin-scale distribution of POC flux and suggestive of a sinking POC --> DOC --> bacteria transformation of the carbon. To test this hypothesis, we sought to determine whether the very strong spatial and temporal gradients in POC flux in the Arabian Sea would force similar deep-ocean gradients in bacterial variables. On both a within and …

Fencing Methods To Reduce Deer Damage, Kurt C. Vercauteren, Michael J. Lavelle

Wildlife Damage Management Conference Proceedings

The white-tailed deer (Odocoileus virginianus) may cause more damage than any other wildlife species. Deer damage occurs in various forms including crop production, automobile accidents, aviation collisions on runways, disease transmission, degradation of natural ecosystems, and destruction of ornamental plantings. One practical method of controlling deer damage is through the use of exclusionary fencing. White-tailed deer are challenging to exclude as they are able to jump 3.0-m fences or fit through spaces > 20 cm wide. Some deer problems (disease outbreaks, aircraft runways, and busy highways in deer migration corridors) may necessitate the installation of effective fencing no matter …

Gis At The National Wildlife Research Center, Jean Bourassa, Craig Ramey, Larry Clark, John S. Humphrey

Wildlife Damage Management Conference Proceedings

The National Wildlife Research Center (NWRC), based in Fort Collins, CO, is the research arm for the Animal Plant and Health Inspection Service’s Wildlife Services Program. Its mission is to resolve conflicts between wildlife and humans. The NWRC established a GIS (Geographic Information System) function in 1996. The relevance of GIS to two projects are featured in this poster. Project 1 was conducted in 1996 and was a joint effort between the NWRC and the California Department of Food and Agriculture (CDFA). In this project, 60 Chinese ring-necked pheasants were radio-instrumented and their movements studied. The main goal of the …

Directed Acyclic Graphs, Stephen B. Maurer , '67

Mathematics & Statistics Faculty Works

No abstract provided.

Importance Of Food Ration And Water Temperature On Growth Of Juvenile Green Sunfish (Lepomis Cyanellus), Christopher J. Chizinski, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

A randomized design was used to test the difference in growth rates of juvenile green sunfish (Lepomis cyanellus) subjected to three treatments (food ration, temperature and salinity). Food ration and water temperature were similarly important in affecting growth of juvenile green sunfish. Juvenile green sunfish were found to accomplish similar growth with scarce food and optimum temperature as with abundant food and sub-optimum temperature. This equal and independent relation to biotic and abiotic factors should be expected in a ubiquitous generalist species, such as green sunfish.

Indirect Symbolic Correlation Approach To Unsegmented Text Recognition, George Nagy, Sharad C. Seth, Y. Lin, Shashank K. Mehta

CSE Conference and Workshop Papers

The new non-parametric approach to unsegmented text recognition builds two bipartite graphs that result from the feature-level and lexical comparisons of the same word against a reference string which need not include the query word. The lexical graph preserves the relative order of edges in the feature graph corresponding to correctly recognized features. This observation leads to a subgraph-matching formulation of the recognition problem. An initial implementation proves the robustness of the approach for up-to 20% noise introduced in the feature-level graph.

Double-Tree Scan: A Novel Low-Power Scan-Path Architecture, Bhargab B. Bhattacharya, Sharad C. Seth, Sheng Zhang

CSE Conference and Workshop Papers

In a scan-based system with a large number of flip-flops, a major component of power is consumed during scan-shift and clocking operation in test mode. In this paper, a novel scan-path architecture called double-tree scan (DTS) is proposed that drastically reduces the scan-shift and clock activity during testing. The inherent combinatorial properties of double-tree structure are employed to design the scan architecture, clock gating logic, and a simple shift controller. The design is independent of the structure of the circuit-under-test (CUT) or its test set. It provides a significant reduction both in instantaneous and average power needed for clocking and …

Low-Energy Bist Design For Scan-Based Logic Circuits, Bhargab B. Bhattacharya, Sharad C. Seth, Sheng Zhang

CSE Conference and Workshop Papers

In a random testing environment, a significant amount of energy is wasted in the LFSR and in the CUT by useless patterns that do not contribute to fault dropping. Another major source of energy drainage is the loss due to random switching activity in the CUT and in the scan path between applications of two successive vectors. In this work, a new built-in self-test (BIST) scheme for scan-based circuits is proposed for reducing such energy consumption. A mapping logic is designed which modifies the state transitions of the LFSR such that only the useful vectors are generated according to a …

Agent Based Intrusion Detection And Response System For Wireless Lans, Mohan K Chirumamilla, Byrav Ramamurthy

CSE Conference and Workshop Papers

Wireless LAN technology, despite the numerous advantages it has over competing technologies, has not seen widespread deployment. A primary reason for markets not adopting this technology is its failure to provide adequate security. Data that is sent over wireless links can be compromised with utmost ease. In this project, we propose a distributed agent based intrusion detection and response system for wireless LANs that can detect unauthorized wireless elements like access points, wireless clients that are in promiscuous mode etc. The system reacts to intrusions by either notifying the concerned personnel, in case of rogue access points and promiscuous nodes, …

Inter-Domain Dynamic Routing In Multi-Layer Optical Transport Networks, Xi Yang, Byrav Ramamurthy

CSE Conference and Workshop Papers

Next-generation optical transport networks will automatically and dynamically provision end-to-end connections. In this paper, we study the problem of inter-domain dynamic routing under a multi-layer multi-domain network model, which allows the end-to-end connections to be set up not only across multiple routing domains but also through two transport layers: the optical layer and the digital layer. In this model, a connection can traverse the domain boundary either through optical bypass or through optical-electrical-optical (O/E/O) processing. We propose an inter-domain dynamic routing scheme with modest time complexity to address the problem from an algorithmic perspective.

A Novel Fiber Delay Line Buffering Architecture For Optical Packet Switching, Lin Li, Stephen Scott, Jitender S. Deogun

CSE Conference and Workshop Papers

Due to the lack of optical random access memory, optical fiber delay line (FDL) is currently the only way to implement optical buffering. Feed-forward and feedback are two kinds of FDL structures in optical buffering. Both have advantages and disadvantages. In this paper, we propose a more effective hybrid FDL architecture that combines the merits of both schemes. The core of this switch is the arrayed waveguide grating (AWG) and the tunable wavelength converter (TWC). It requires smaller optical device sizes and fewer wavelengths and has less noise than feedback architecture. At the same time, it can facilitate preemptive priority …

Patterns And Trends Of Soil Climate Regimes And Drought Events In The Northern Great Plains, William J. Waltman, Stephen M. Goddard, S. E. Reichenbach, Mark Svoboda, Michael Hayes, J. S. Peake

CSE Conference and Workshop Papers

Drought is the dominant process of crop loss nationally and within Nebraska. Nearly twothirds of the 18.6 million harvested acres are covered by crop insurance (USDA/RMA, 2003; USDA/NASS, 2003). For the most part, Nebraska’s crop losses range from $50 to 75 million in non-drought years, but the losses approach nearly $200 million in drought years, such as 2000. The past growing season (2002) crop losses are projected to greatly exceed $375 million in Nebraska and more than $4 billion nationally (USDA/RMA, 2003). The analysis and understanding of drought processes in the Great Plains is an important component to developing drought …

A New Efficient Algorithm For Solving The Simple Temporal Problem, Lin Xu, Berthe Y. Choueiry

CSE Conference and Workshop Papers

Motivation for Simple Temporal Problem (STP)

STP - TCSP - DTP

Consistency properties & algorithms

General CSPs

STP

Contributions

Use (improved) PPC for STP

Refine it into ΔSTP

Evaluation on random instances, 3 generators

Summary & new results

A New Efficient Algorithm For Solving The Simple Temporal Problem, Lin Xu, Berthe Y. Choueiry

CSE Conference and Workshop Papers

In this paper we propose a new efficient algorithm, the Δ STP-solver, for computing the minimal network of the Simple Temporal Problem (STP). This algorithm achieves high performance by exploiting a topological property of the constraint graph (i.e., triangulation) and a semantic property of the constraints (i.e., convexity) in light of the results reported by Bliek and Sam-Haroud [1], which were presented for general CSPs and have not yet been applied to temporal networks. Importantly, we design the constraint propagation in Δ STP-solver to operate on triangles instead of operating on edges and implicitly guarantee the decomposition of …

Determination Of H_{2}O_{2} Content Of Various Water Samples Using A Chemiluminescence Technique, Tuğba Tüğsüz, Elmas Gök, Serdar Ateş

Turkish Journal of Chemistry

Hydrogen peroxide (H_{2}O_{2}) plays an important role in natural water samples. In this study H_{2}O_{2} concentrations were quantified in different water samples by chemiluminescence detection. This method was chosen because of its high sensitivity and suitability for determining low concentrations of H_{2}O_{2}. H_{2}O_{2} is introduced to the oxidation reaction of alkaline luminol solutions in the presence of Co^{2 + } ion catalyst. When these components are mixed, blue light (\lambda = 440 nm) is emitted. Maximum chemiluminescence intensity occurs within 2 s after mixing and is continuous for up to a few minutes, permitting accurate measurements at selected delay times. …

Affine Manifolds, Log Structures, And Mirror Symmetry, Mark Gross, Bernd Siebert

Turkish Journal of Mathematics

We outline work in progress suggesting an algebro-geometric version of the Strominger-Yau-Zaslow conjecture. We define the notion of a toric degeneration, a special case of a maximally unipotent degeneration of Calabi-Yau manifolds. We then show how in this case the dual intersection complex has a natural structure of an affine manifold with singularities. If the degeneration is polarized, we also obtain an intersection complex, also an affine manifold with singularities, related by a discrete Legendre transform to the dual intersection complex. Finally, we introduce log structures as a way of reversing this construction: given an affine manifold with singularities with …

Duality And Fibrations On G_2 Manifolds, Sergei Gukov, Shing-Tung Yau, Eric Zaslow

Turkish Journal of Mathematics

We argue that G_2 manifolds for M-theory admitting string theory Calabi-Yau duals are fibered by coassociative submanifolds. Dual theories are constructed using the moduli space of M-five-brane fibers as target space. Mirror symmetry and various string and M-theory dualities involving G_2 manifolds may be incorporated into this framework. To give some examples, we construct two non-compact manifolds with G_2 structures: one with a K3 fibration, and one with a torus fibration and a metric of G_2 holonomy. Kaluza-Klein reduction of the latter solution gives abelian BPS monopoles in 3 + 1 dimensions.

On Some Properties Of Szasz-Mirakyan Operators In Hölder Spaces, Zbigniew Walczak, Lucyna Rempulska

Turkish Journal of Mathematics

We study some properties of modified Szasz-Mirakyan operators in Hölder exponential weighted spaces. We give theorems on the degree of approximation of functions by these operators.

Shape Operator A_H For Slant Submanifolds In Generalized Complex Space Forms, Adela Mihai

Turkish Journal of Mathematics

In this article, we establish an inequality between the sectional curvature function K and the shape operator A_H at the mean curvature vector for slant submanifolds in generalized complex space forms. Also a sharp relationship between the k-Ricci curvature and the shape operator A_H is proved.

Change Of Birefringence In Dye-Doped Nematic Liquid Crystals Under Laser Illumination, S. Eren San, Oğuz Köysal, Serhat Özder, F. Necati̇ Ecevi̇t

Turkish Journal of Physics

Birefringence property of E7 nematic liquid crystal is investigated via voltage dependent transmittance spectrums. Measurements are performed at wavelength 632.8 nm, which is the absorbance peak of our sample including anthraquinone derivative Disperse Blue 14. Results of dye-doped samples are compared with those undoped for dark and laser illuminated cases. It was observed that birefringence is dependent on laser illumination for dye-doped samples, up to a threshold voltage after which it is constant.

Decoherence In Two Coupled Qubits, Kristian Rabenstein, Dmitri V. Averin

Turkish Journal of Physics

We have developed quantitative description of quantum coherent oscillations in the system of two coupled qubits in the presence of weak decoherence that in general can be correlated between the two qubits. It is shown that in the experimentally realized scheme of excitation of the oscillations, their waveform is not very sensitive to the magnitude of decoherence correlations. Modification of this scheme into potentially useful probe of the degree of decoherence correlations at the two qubits is suggested.

Characterization Of Native And Bypass Human Coronary Artery Plaque Deposits From The Same Heart: Investigation Of The Chemical Form Of Calcium In Human Coronary Artery Plaque Deposits, Serigne Thiam

LSU Doctoral Dissertations

Gradual deposits of lipids, proteins, and calcium on the coronary arterial walls cause atherosclerosis, leading to blockage of the blood flow and possible heart attack. Despite many studies, the mechanism underlying these processes remains unclear. In this research, differences between native and bypass plaque deposits from the same heart were examined. In addition, the crystalline and the amorphous plaques within these native and bypass vessels were characterized. The techniques used to characterize the deposits included inductively coupled plasma mass spectrometry (ICPMS), solid-state nuclear magnetic resonance (NMR), high performance liquid chromatography (HPLC), etc. The results from the ICPMS technique showed that …

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 …

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 …