Digital Commons Network^™

The Generalized Segal-Bargmann Transform And Special Functions, Mark Davidson, Gestur Ólafsson

Faculty Publications

Analysis of function spaces and special functions are closely related to the representation theory of Lie groups. We explain here the connection between the Laguerre functions, the Laguerre polynomials, and the Meixner-Pollacyck polynomials on the one side, and highest weight representations of Hermitian Lie groups on the other side. The representation theory is used to derive differential equations and recursion relations satisfied by those special functions.

Symbolically Aided Model Development For An Induction Machine In Virtual Test Bed, Wenzhong Gao, Eugene V. Slovodnik, Roger A. Dougal

Faculty Publications

A new phase-domain induction machine model for use in power system dynamic simulation is developed with the aid of a symbolic tool. The symbolic tool can automatically construct a time-domain power system component model in the resistive companion form (RCF) that is widely used in time-domain simulators. The automatic differentiation technique (aDT) is utilized within the context of a symbolic modeling language, and the tool has been implemented for the virtual test bed (VTB) simulation environment. The new induction machine model was used to study start-up transients of an induction motor. The new model was verified by comparing the simulation …

Electronic Structure Of Nuclear-Spin-Polarization-Induced Quantum Dots, Yuriy V. Pershin Dr

Faculty Publications

We study a system in which electrons in a two-dimensional electron gas are confined by a nonhomogeneous nuclear-spin polarization. The system consists of a heterostructure that has nonzero nuclei spins. We show that in this system electrons can be confined into a dot region through a local nuclear-spin polarization. The nuclear-spin-polarization-induced quantum dot has interesting properties indicating that electron energy levels are time dependent because of the nuclear-spin relaxation and diffusion processes. Electron confining potential is a solution of diffusion equation with relaxation. Experimental investigations of the time dependence of electron energy levels will result in more information about nuclear-spin …

Slow Spin Relaxation In Two-Dimensional Electron Systems With Antidots, Yuriy V. Pershin Dr, Vladimir Privman

Faculty Publications

We report a Monte Carlo investigation of the effect of a lattice of antidots on spin relaxation in twodimensional electron systems. The spin relaxation time is calculated as a function of geometrical parameters describing the antidot lattice, namely the antidot radius and the distance between their centers. It is shown that spin polarization relaxation can be efficiently suppressed by the chaotic spatial motion due to the antidot lattice. This phenomenon offers a new approach to spin coherence manipulation in spintronics devices.

Human Glutaminyl Cyclase And Bacterial Zinc Aminopeptidase Share A Common Fold And Active Site, Rachell E. Booth, Simon C. Lovell, Stephanie A. Misquitta, Robert C. Bateman Jr.

Faculty Publications

Background: Glutaminyl cyclase (QC) forms the pyroglutamyl residue at the amino terminus of numerous secretory peptides and proteins. We previously proposed the mammalian QC has some features in common with zinc aminopeptidases. We now have generated a structural model for human QC based on the aminopeptidase fold (pdb code 1AMP) and mutated the apparent active site residues to assess their role in QC catalysis.

Results: The structural model proposed here for human QC, deposited in the protein databank as 1MOI, is supported by a variety of fold prediction programs, by the circular dichroism spectrum, and by the presence …

Boron Alloying In Gan, Gus L. W. Hart, Laurian Escalanti

Faculty Publications

Using first-principles calculations in the local density approximation, we studied effects of adding up to 6% boron to zinc-blende GaN. We found that the band gap increases monotonically with boron incorporation, in agreement with experiment. A composition-independent band-gap bowing parameter of 4.30 eV was determined, and proved to be large compared to bowing for other mixed cation systems. The formation enthalpy of mixing, ΔH, was determined for BxGa1-xN, BxGa1-xAs, and GaAs1-xNx. A comparison of enthalpies indicates that the production of BxGa1-xN films with boron concentrations of at least 5% may be possible.

Self-Similarity And Symmetries Of Pascal’S Triangles And Simplices Mod P, Richard P. Kubelka

Faculty Publications

No abstract provided.

Wide-Band/Dual-Band Packaged Antenna For 5-6 Ghz Wlan Application, Mohammod Ali, Tuangsit Sittironnarit, Huan-Sheng Hwang, Robert A. Sadler, Gerard James Hayes

Faculty Publications

A wide-band/dual-band packaged antenna is proposed for wireless local-area network (WLAN) applications in the 5.15-5.35 GHz and 5.725-5.825 GHz frequency range. The antenna is internal to the housing of a personal digital assistant, such as a Palm organizer, and has the dimensions of 28 by 9 by 3 ram on an FR4 substrate. The antenna meets or exceeds the bandwidth requirements for the dual-band IEEE 802.11a WLAN applications (5.15-5.35 GHz and 5.725-5.825 GHz) within 2:1 voltage standing-wave ratio.

Laboratory Project In Wireless Fsk Receiver Design, Michael A. Jensen, Cynthia Fuse, Raymond Woodward

Faculty Publications

This paper describes a wireless local area network laboratory project that provides senior and first-year graduate students in microwave engineering courses the opportunity to design, build, and test several passive microstrip components and integrate them into a working system. Students design filters, couplers, amplifiers, diode detectors, quarter-wave transformers, antennas, and stub matching networks in weekly labs that parallel-lectures in a one-semester microwave engineering course. This paper also describes simple inexpensive prototyping and testing methods that have been used in this course. Laboratory materials and technical details of the design are provided on the web for students and educators.

Energy Conserving Approximations To The Quantum Potential: Dynamics With Linearized Quantum Force, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

Solution of the Schrödinger equation within the de Broglie–Bohm formulation is based on propagation of trajectories in the presence of a nonlocal quantum potential. We present a new strategy for defining approximate quantum potentials within a restricted trial function by performing the optimal fit to the log-derivatives of the wave function density. This procedure results in the energy-conserving dynamics for a closed system. For one particular form of the trial function leading to the linear quantum force, the optimization problem is solved analytically in terms of the first and second moments of the weighted trajectory distribution. This approach gives exact …

Transcriptome-Based Determination Of Multiple Transcription Regulator Activities In Escherichia Coli By Using Network Component Analysis, Katy Kao, Young-Lyeol Yang, Riccardo Boscolo, Chiara Sabatti, Vwani Roychowdhury, James Liao

Faculty Publications

Cells adjust gene expression profiles in response to environmental and physiological changes through a series of signal transduction pathways. Upon activation or deactivation, the terminal regulators bind to or dissociate from DNA, respectively, and modulate transcriptional activities on particular promoters. Traditionally, individual reporter genes have been used to detect the activity of the transcription factors. This approach works well for simple, non-overlapping transcription pathways. For complex transcriptional networks, more sophisticated tools are required to deconvolute the contribution of each regulator. Here, we demonstrate the utility of network component analysis in determining multiple transcription factor activities based on transcriptome profiles and …

Open-Ended Problem-Solving Skills In Thermal-Fluids Engineering, Nikos J. Mourtos, Nicole Dejong-Okamoto, Jinny Rhee

Faculty Publications

Problem-solving skills have always been important in many professions. However, ABET EC 2000 recently placed a new focus on these skills in engineering education with outcome 3e, which states that engineering graduates must have an ability to identify, formulate and solve engineering problems. Problem-solving is defined as a process used to obtain a best answer to an unknown or a decision that is subject to some constraints. Problem-solving is not the same as textbook exercise solving, which is very common in engineering curricula. In the article, the authors first define engineering problem-solving and, in particular, what it means to identify …

"A New Phase Of The Complex Trinitratotris(Triphenylphosphineoxide)Neodymium(Lll), J. Brannon Gary

Faculty Publications

There has been considerable interest in the complexes formed by the lanthanides with various monodentate neutral ligands with O as the donor atom. Phosphine oxides, in particular, have proven useful in complexing to lanthanide metal ions and have found practical application in the solvent extraction and separation of lanthanides.1 Several lanthanide(III) nitrate complexes with triphenylphosphine oxide (OPPh3) have been prepared resulting in complexes having as few as two and as many as four OPPh3 groups per lanthanide center.2−4 An earlier study by Cousins and Hart5 identified the complex [Nd(OPPh3)3(NO3)3]. Two crystal phases of this same complex were briefly reported later …

Economic Analysis Of Pruning And Low-Density Management Compared To Traditional Management Of Loblolly Pine Plantations In East Texas, Ching Hsun Huang, Gary D. Kronrad

Faculty Publications

Economic analyses were conducted to compare traditional loblolly pine (Pinus taeda L.) timber management to low-density management combined with pruning in East Texas. Soil expectation values were used to determine the financially optimal thinning and final harvesting schedules (including rotation length, and the timing, frequency and intensity of thinning). Two stumpage price assumptions were made: market price and premium price for pruned, clear sawlogs. Five site indices (50 to 90) and six real alternative rates of return (ARR) (2.5 to 15.0%) were employed. Results indicate that if the market price of sawtimber is $450/mbf, traditional management is more profitable for …

The Red-Cockaded Woodpecker Cavity Tree: A Very Special Pine, Richard N. Conner, D. Craig Rudolph, Daniel Saenz, Robert H. Johnson

Faculty Publications

The adaptation of red-cockaded woodpeckers (Picoides borealis) to fire-maintained southern pine ecosystems has included the development of behaviors that permit the species to use living pines for their cavity trees. Their adaptation to pine ecosystems has also involved a major adjustment in the species' breeding system to cooperative breeding, probably in response to the extended time period required to excavate a completed cavity in a living pine and the relative rarity of completed cavities for nesting. The characteristics of live pines make them variable in their suitability as cavity trees, leading to the evolution of selection behavior among woodpeckers. Red-cockaded …

Comparison Between Regenerators And Non-Regenerators In Mississippi: A Discriminant Analysis, Kathryn G. Arano, Ian A. Munn, John E. Gunter, Steven H. Bullard, Max L. Doolittle

Faculty Publications

Nonindustrial private forestland (NIPF) landowners in Mississippi who recently harvested timber were surveyed to examine their regeneration behavior. Differences between regenerators and nonregenerators were investigated by looking at the different factors affecting reforestation decisions. A discriminant analysis was used to identify factors that were useful in differentiating between regenerators and nonregenerators. Ownership size; sociodemographic characteristics such as income, education, place of residence, and age; awareness of existing government incentive/assistance programs; and participation in educational programs were significant variables in differentiating between regenerators and nonregenerators. Landowners who own larger timberlands had a higher propensity to engage in regeneration activities after harvests. …

Inorganic Nitrogen Transformations At High Loading Rates In An Oligohaline Estuary, R. Eugene Turner, Q. Dortch, Nancy N. Rabalais

Faculty Publications

A well-defined nitrogen retention and turnover budget was estimated for a shallow oligohaline lake (Lake Pontchartrain, Louisiana, USA). In 1997 a month-long diversion of the Mississippi River filled the Lake with highly concentrated river water (80 µM nitrate) and lowered the salinity to 0 psu within 2 weeks. After the spillway was closed the Lake mixed with estuarine tidal waters and came to equilibrium over 4 months with the riverine, atmospheric and offshore water nitrogen sources. A flushing rate of 1.78% d−1 was estimated by analyzing a plot of ln salinity versus time for the first 120 days after the …

Suspended Sediment, C, N, P, And Si Yields From The Mississippi River Basin, R. Eugene Turner, Nancy N. Rabalais

Faculty Publications

The annual loads of C,N,P, silicate, total suspended sediment (mass) and their yields (mass area−1) were estimated for six watersheds of the Mississippi River Basin (MRB) using water quality and water discharge records for 1973 to 1994. The highest load of suspended sediments is from the Missouri watershed (58 mt km2 yr−1), which is also the largest among the six major sub-basins. The Ohio watershed delivers the largest load of water (38%). The Upper Mississippi has the largest total nitrogen load (32%) and yield (1120 kg TN km2 yr−1). The loading of organic carbon, total phosphorus and silicate from the …

Below-Ground Biomass In Healthy And Impaired Salt Marshes, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee, Thomas A. Oswald

Faculty Publications

Twelve salt marshes in south Louisiana (USA) were classified as either ‘impaired’ or ‘healthy’ before a summer sample collection of above- and below-ground biomass and determination of sediment accretion rates. The above-ground biomass of plant tissues was the same at both impaired and healthy salt marshes and was not a good predictor of marsh health. However, below-ground root biomass in the upper 30 cm was much lower in the impaired marshes compared to the healthy marshes. Compromises to root production apparently occur before there is an obvious consequence to the above-ground biomass, which may quickly collapse before remedial action can …

Human Capital And Learning As A Source Of Sustainable Competitive Advantage, Nile W. Hatch, Jeffrey H. Dyer

Faculty Publications

This paper seeks to identify the sources of wide and persistent variations in learning performance in the semiconductor manufacturing industry. In the resource-based view of the firm, human capital is frequently assumed to contribute to competitive advantage due to its inimitability based on its intangible, firm-specific, and socially complex nature. Consistent with this view, we find that investments in firm-specific human capital have a significant impact on learning and firm performance. More specifically, human capital selection (education requirements and screening), development through training, and deployment significantly improve learning by doing, which in turn improves performance. However, we find that acquiring …

Risky Loss Distributions And Modeling The Loss Reserve Pay-Out Tail, J. David Cummins, James B. Mcdonald, Craig B. Merrill

Faculty Publications

Although an extensive literature has developed on modeling the loss reserve runoff triangle, the estimation of severity distributions applicable to claims settled in specific cells of the runoff triangle has received little attention in the literature. This paper proposes the use of a very flexible probability density function, the generalized beta of the 2nd kind (GB2) to model severity distributions in the cells of the runoff triangle and illustrates the use of the GB2 based on a sample of nearly 500,000 products liability paid claims. The results show that the GB2 provides a significantly better fit to the severity data …

Guided Model Checking With A Bayesian Meta-Heuristic, Michael D. Jones, Peter Lamborn, Kevin Seppi

Faculty Publications

This paper presents a formal verification algorithm for finding errors in models of complex concurrent systems. The algorithm improves explicit guided model checking by applying the Empirical Bayes method to revise heuristic estimates of the distance from a given state to an error state. Guided search using the revised estimates finds errors with less search effort than the original estimates.

Teachable Moments For Teachers…Teaching Students About The Legal Reader: The Reader Who Won’T Be Taken For A Ride, Jessica E. Slavin

Faculty Publications

No abstract provided.

Spotlight: Response To Violence Against Women At The University Of Missouri At Columbia, Mary M. Beck

Faculty Publications

The University of Missouri (“MU”) sits in the picturesque college town of Columbia on the largest and oldest campus of the Missouri University system. MU is a land grant institution created with funds and land appropriated by the Morrill Acts of 1862 and 1890. The University “honors [that public trust] and accepts the associated accountability” by acquiring, creating, transmitting, and preserving knowledge. “MU's primary mission in research and doctoral education . . . provides the basis for service to the people of [Missouri] via outreach programs.” Domestic violence impacts MU's land grant influenced service mission. Its organizational departments, educational units, …

Instruct The Jury: Crane's Serious Difficulty Requirement & Due Process, Kenneth Gaines

Faculty Publications

No abstract provided.

Ake V. Oklahoma: The Right To Expert Assistance In A Post-Daubert, Post-Dna World, Paul C. Giannelli

Faculty Publications

Although securing the services of defense experts to examine evidence, to advise counsel, and to testify at trial is frequently critical in modern criminal litigation, it was not until 1985 that the United States Supreme Court in Ake v. Oklahoma, 470 U.S. 68 (1985), recognized, for the first time, a constitutional right to expert assistance. In a system in which an overwhelming majority of criminal defendants are indigent, Ake was a landmark case. Nevertheless, the Ake Court could not have anticipated how the advent of DNA evidence would revolutionize forensic science or how the Daubert trilogy would alter the judicial …

‘Lose In Vietnam, Bring Our Boys Home’, Robert N. Strassfeld

Faculty Publications

This Article examines the contest over dissent and loyalty during the Vietnam War. The Johnson and Nixon Administrations used an array of weapons to discourage or silence antiwar opposition. These included criminal prosecutions for "disloyal speech," a tool that they used with less frequency than some other administrations in times of war; prosecutions for other "crimes" that served as pretext for prosecuting disloyal speech; infiltration and harassment; and an attempt to characterize their critics as disloyal. The antiwar movement, in turn, responded to allegations that dissent equaled disloyalty by offering an alternative vision of loyalty and patriotism. In so doing, …

Loop Quantum Gravity And The Cyclic Universe, Martin Bojowald, Roy Maartens, Parampreet Singh

Faculty Publications

Loop quantum gravity introduces strong nonperturbative modifications to the dynamical equations in the semiclassical regime, which are responsible for various novel effects, including resolution of the classical singularity in a Friedman universe. Here we investigate the modifications for the case of a cyclic universe potential, assuming that we can apply the four-dimensional loop quantum formalism within the effective four-dimensional theory of the cyclic scenario. We find that loop quantum effects can dramatically alter the near-collision dynamics of the cyclic scenario. In the kinetic-dominated collapse era, the scalar field is effectively frozen by loop quantum friction, so that the branes approach …

Inflationary Cosmology And Quantization Ambiguities In Semiclassical Loop Quantum Gravity, Martin Bojowald, James E. Lidsey, David J. Mulryne, Parampreet Singh, Reza Tavakol

Faculty Publications

In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential. In principle, this mechanism can generate the conditions that subsequently lead to slow-roll inflation. The consequences for this mechanism of various quantization ambiguities arising within loop quantum cosmology are considered. For the case of a quadratic potential, it is found that some quantization procedures are more likely to generate a phase of slow-roll inflation. In general, however, loop quantum cosmology is robust to ambiguities in the quantization and extends the range of initial conditions for inflation. © …

Climbing Bloom's Ladder, Isiah M. Warner

Faculty Publications

No abstract provided.