Digital Commons Network^™

Responses Of An Arctic Landscape To Lateglacial And Early Holocene Climatic Changes: The Importance Of Moisture, Daniel H. Mann, Dorothy M. Peteet, Richard E. Reanier, Michael L. Kunz

United States National Aeronautics and Space Administration: Publications

Many of the physical and biological processes that characterize arctic ecosystems are unique to high latitudes, and their sensitivities to climate change are poorly understood. Stratigraphic records of land–surface processes and vegetation change in the Arctic Foothills of northern Alaska reveal how tundra landscapes responded to climatic changes between 13,000 and 8000 ¹⁴Cyr BP. Peat deposition began and shrub vegetation became widespread ca. 12,500 ¹⁴Cyr BP, probably in response to the advent of warmer and wetter climate. Increased slope erosion caused rapid alluviation in valleys, and Populus trees spread northward along braided floodplains before 11,000 ¹⁴Cyr BP. …

Independent- Jul. 24, 2001, Scott Plencner

The Independent (1988-present)

No abstract provided.

Microcavity Surface Emitting Laser, Stewart Feld, John P. Loehr, James A. Lott

AFIT Patents

A three-dimensional waveguiding structure for a microcavity surface-emitting laser is described in which native aluminum oxide layers provide control of intracavity waveguiding and the laser optical mode structure of the emitted beam. Microcavity lasers described herein account for the blueshift of the emission wavelength as the laser lateral dimensions are reduced to or below the emission wavelength.

The Three-Dimensional Random Field Ising Magnet: Interfaces, Scaling, And The Nature Of States, Alan Middleton, Daniel S. Fisher

Physics - All Scholarship

The nature of the zero temperature ordering transition in the 3D Gaussian random field Ising magnet is studied numerically, aided by scaling analyses. In the ferromagnetic phase the scaling of the roughness of the domain walls, $w\sim L^\zeta$, is consistent with the theoretical prediction $\zeta = 2/3$. As the randomness is increased through the transition, the probability distribution of the interfacial tension of domain walls scales as for a single second order transition. At the critical point, the fractal dimensions of domain walls and the fractal dimension of the outer surface of spin clusters are investigated: there are at least …

Determination Of 4,4′-Dinitrocarbanilide (Dnc), The Active Component Of The Antifertility Agent Nicarbazin, In Chicken, Duck, And Goose Plasma, Thomas M. Primus, Dennis J. Kohler, Margaret A. Goodall, Christi Yoder, Doreen Griffin, Lowell A. Miller, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

4,4′-Dinitrocarbanilide (DNC) was extracted from chicken, duck, and goose plasma and isolated by reversed-phase high-performance liquid chromatography. DNC was detected by ultraviolet absorbance at 347 nm and quantified by comparison to a calibration standard. Recovery data were determined by analyzing DNC-fortified control plasma. The mean recovery of DNC in fortified chicken plasma samples was 99.7 ± 1.9% for 0.18 and 9.1 ppm DNC, and in fortified duck and goose plasma samples was 99.5 ± 4.9% and 101.4 ± 4.5%, respectively, for 0.18, 9.1, and 18 ppm DNC.

Diets Of Wild Versus Released, And Pen-Raised White-Tailed Deer In Southeastern Louisiana, Richard James Meyers

LSU Historical Dissertations and Theses

Twenty pen-raised white-tailed deer (Odocoileus virginianus) were released into mixed pine-hardwood forest habitat in southeastern Louisiana to compare their seasonal diets to the diets of the wild white-tailed deer population. Microhistological analysis was used to estimate the botanical composition of fecal pellet samples collected from both populations of deer over four consecutive seasons. Wild and pen-raised deer diets were found to be an average of 75.18% similar during the entire year of the study, and were significantly associated during all seasons (P < 0.001), indicating that all deer foraged on similar plant taxa in similar proportions regardless of season. Both populations of deer were found to be predominantly browsers during all seasons, with browse and fruit accounting for a yearly average of >55% of deer diets. Results from this study indicate that rehabilitated or translocated deer released into new environments …

Microwave Ionization Of An Atomic Electron Wave Packet, Michael Noel, Lung Ko, T. F. Gallagher

Physics Faculty Research and Scholarship

A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization.

Daily Eastern News: July 23, 2001, Eastern Illinois University

July

No abstract provided.

Synthesis And Characterization Of Novel Chiral Chromophores For Nonlinear Optical Applications, Kenneth D. Singer, Rolfe G. Petschek

Faculty Scholarship

We report the design, synthesis and characterization of novel conjugated chiral materials, based on the derivatives of camphorquinone as shown below, for nonlinear optics. Several conjugated chiral monomers have been prepared and characterized. A x-ray single crystal study was also performed on one of the chiral monomer. The chiral conjugated polymers were prepared from polycondensation of conjugated chiral diolmonomer with di-functional and multifunctional co-monomers. We present results of synthesis and characterization of the conjugated chiral materials.

An All Optical Laser Wakefield Electron Injector, Donald P. Umstadter

Donald Umstadter Publications

The personnel who were supported by the grant included the P.I. (Prof. Umstadter), several research scientists (A. Maksimchuk and V. Yanovsky), a postdoc (P. Zhang) and several graduate and undergraduate students. Although there were several setbacks in developing the novel laser technology required to produce a monoenergetic beam of electrons from an all-optical accelerator, several important steps were taken towards reaching that ultimate goal. The most important outcome of this project was that we demonstrated the principle of optical control of laser accelerators, namely, that one laser pulse could modify the properties (e.g., emittance and electron number) of an electron …

Deafdigest Gold: Vol. 5, No. 51 July 22 2001, Barry Strassler

DeafDigest Gold 2001

No abstract provided.

Aurora Working Group: Dsr Front End Lvcsr Evaluation — Baseline Recognition System Description, Naveen Parihar, Joseph Picone

Publications

In this document we describe the features of the baseline system to be used in the Distributed Speech Recognition (DSR) front end large vocabulary continuous speech recognition (LVCSR) evaluations being conducted by the Aurora Working Group of the European Telecommunications Standards Institute (ETSI). The objective of these evaluations is to determine the robustness of different front ends for use in client/server type telecommunications applications. As such, our experiments are designed to test the following focus conditions on the DARPA Wall Street Journal (WSJ0) corpus using a 5000-word closed-loop vocabulary and a bigram language model:

1. Additive Noise: six noise conditions …

Measurement And Interpretation Of Deuterium-Line Emission In The Orion Nebula, C. R. O'Dell, Gary J. Ferland, W. J. Henney

Physics and Astronomy Faculty Publications

We present new observations of the deuterium and hydrogen Balmer lines in the Orion Nebula. There is a real variation in the deuterium-to-hydrogen line ratios across the nebula, being greatest in the emission from the largest proplyd (Orion 244-440). We also present the results of a detailed model for the emission of these lines, the hydrogen lines being the result of photoionization and recombination while the deuterium lines are produced by fluorescent excitation of the upper energy states by the far-UV radiation from θ¹ Ori C. Comparison of the observations and predictions of the line intensities shows good agreement, …

Illinois State University Board Of Trustees Meeting Materials, July 20, 2001, Board Of Trustees

Illinois State University Board of Trustees (1995-2013)

Minutes, reports, and action items relating to the July 20, 2001 meeting of the Illinois State University Board of Trustees.

Structural And Functional Imaging With Carbon Nanotube Afm Probes, J. H. Hafner, Chin Li Cheung, A. T. Woolley, C. M. Lieber

Barry Chin Li Cheung Publications

Atomic force microscopy (AFM) has great potential as a tool for structural biology, a field in which there is increasing demand to characterize larger and more complex biomolecular systems. However, the poorly characterized silicon and silicon nitride probe tips currently employed in AFM limit its biological applications. Carbon nanotubes represent ideal AFM tip materials due to their small diameter, high aspect ratio, large Young’s modulus, mechanical robustness, well-defined structure, and unique chemical properties. Nanotube probes were first fabricated by manual assembly, but more recent methods based on chemical vapor deposition provide higher resolution probes and are geared towards mass production, …

Improved Hopfield Networks By Training With Noisy Data, Fred Clift, Tony R. Martinez

Faculty Publications

A new approach to training a generalized Hopfield network is developed and evaluated in this work. Both the weight symmetricity constraint and the zero self-connection constraint are removed from standard Hopfield networks. Training is accomplished with Back-Propagation Through Time, using noisy versions of the memorized patterns. Training in this way is referred to as Noisy Associative Training (NAT). Performance of NAT is evaluated on both random and correlated data. NAT has been tested on several data sets, with a large number of training runs for each experiment. The data sets used include uniformly distributed random data and several data sets …

Improving The Hopfield Network Through Beam Search, Tony R. Martinez, Xinchuan Zeng

Faculty Publications

In this paper we propose a beam search mechanism to improve the performance of the Hopfield network for solving optimization problems. The beam search readjusts the top M (M > 1) activated neurons to more similar activation levels in the early phase of relaxation, so that the network has the opportunity to explore more alternative, potentially better solutions. We evaluated this approach using a large number of simulations (20,000 for each parameter setting), based on 200 randomly generated city distributions of the 10-city traveling salesman problem. The results show that the beam search has the capability of significantly improving the network …

Optimal Artificial Neural Network Architecture Selection For Bagging, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer

Faculty Publications

This paper studies the performance of standard architecture selection strategies, such as cost/performance and CV based strategies, for voting methods such as bagging. It is shown that standard architecture selection strategies are not optimal for voting methods and tend to underestimate the complexity of the optimal network architecture, since they only examine the performance of the network on an individual basis and do not consider the correlation between responses from multiple networks.

Speed Training: Improving The Rate Of Backpropagation Learning Through Stochastic Sample Presentation, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer

Faculty Publications

Artificial neural networks provide an effective empirical predictive model for pattern classification. However, using complex neural networks to learn very large training sets is often problematic, imposing prohibitive time constraints on the training process. We present four practical methods for dramatically decreasing training time through dynamic stochastic sample presentation, a technique we call speed training. These methods are shown to be robust to retaining generalization accuracy over a diverse collection of real world data sets. In particular, the SET technique achieves a training speedup of 4278% on a large OCR database with no detectable loss in generalization.

The Need For Small Learning Rates On Large Problems, Tony R. Martinez, D. Randall Wilson

Faculty Publications

In gradient descent learning algorithms such as error backpropagation, the learning rate parameter can have a significant effect on generalization accuracy. In particular, decreasing the learning rate below that which yields the fastest convergence can significantly improve generalization accuracy, especially on large, complex problems. The learning rate also directly affects training speed, but not necessarily in the way that many people expect. Many neural network practitioners currently attempt to use the largest learning rate that still allows for convergence, in order to improve training speed. However, a learning rate that is too large can be as slow as a learning …

If I Had A Hammer..., Robert Jordan

University of Mississippi News

UNIVERSITY, Miss. -- University of Mississippi Kids College student Quinton Holman, 10, of Oxford gets help from Ole Miss education professor Dr. David Rock, as he drives a screw into a pre-fabricated house Thursday at UM's Yerby Center auditorium.

Three-Dimensional Spectral Classification Of Low-Metallicity Stars Using Artificial Neural Networks, Shawn Snider, Ted Von Hippel, Carlos Allende Prieto, Timothy C. Beers, Christopher Sneden, Et Al.

Publications

We explore the application of artificial neural networks (ANNs) for the estimation of atmospheric parameters (Teff, log g, and [Fe/H]) for Galactic F- and G-type stars. The ANNs are fed with medium-resolution (Δλ ~ 1-2 Å) non-flux-calibrated spectroscopic observations. From a sample of 279 stars with previous high-resolution determinations of metallicity and a set of (external) estimates of temperature and surface gravity, our ANNs are able to predict Teff with an accuracy of σ(Teff) = 135-150 K over the range 4250 ≤ Teff ≤ 6500 K, log g with an accuracy of σ(log …

Lazy Training: Improving Backpropagation Learning Through Network Interaction, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer

Faculty Publications

Backpropagation, similar to most high-order learning algorithms, is prone to overfitting. We address this issue by introducing interactive training (IT), a logical extension to backpropagation training that employs interaction among multiple networks. This method is based on the theory that centralized control is more effective for learning in deep problem spaces in a multi-agent paradigm. IT methods allow networks to work together to form more complex systems while not restraining their individual ability to specialize. Lazy training, an implementation of IT that minimizes misclassification error, is presented. Lazy training discourages overfitting and is conducive to higher accuracy in multiclass problems …

Write Once, Move Anywhere: Toward Dynamic Interoperability Of Mobile Agent Systems, Arne Grimstrup, Robert Gray, David Kotz, Thomas Cowin, Greg Hill, Niranjan Suri, Daria Chacon, Martin Hofmann

Computer Science Technical Reports

Mobile agents are an increasingly popular paradigm, and in recent years there has been a proliferation of mobile-agent systems. These systems are, however, largely incompatible with each other. In particular, agents cannot migrate to a host that runs a different mobile-agent system. Prior approaches to interoperability have tried to force agents to use a common API, and so far none have succeeded. Our goal, summarized in the catch phrase ``Write Once, Move Anywhere,'' led to our efforts to develop mechanisms that support dynamic runtime interoperability of mobile-agent systems. This paper describes the Grid Mobile-Agent System, which allows agents to migrate …

Automatic Closure Of Invariant Linear Manifolds For Operator Algebras, Allan P. Donsig, Alan Hopenwasser, David R. Pitts

Department of Mathematics: Faculty Publications

Kadison's transitivity theorem implies that, for irreducible representations of C*-algebras, every invariant linear manifold is closed. It is known that CSL algebras have this property if, and only if, the lattice is hyperatomic (every projection is generated by a nite number of atoms). We show several other conditions are equivalent, including the condition that every invariant linear manifold is singly generated.

We show that two families of norm closed operator algebras have this property. First, let L be a CSL and suppose A is a norm closed algebra which is weakly dense in Alg L and is a bimodule over …

Campus Chronicle (Vol. 4, No. 1), Valparaiso University

Campus Chronicle

No abstract provided.

Young Girls Reach For The Stars At Unh Residential Science Camp, Erika Mantz

Media Relations

No abstract provided.

Snags In Beaver Ponds And Indications Of Use By Primary Cavity-Nesting Birds In The Western Oregon Cascades, Jacqueline I. Fern

Dissertations and Theses

Dead trees, or snag , are used by primary cavity-nesting birds for nesting, foraging, and roosting and are essential habitat for the e species. Snags formed in beaver ponds due to flooded conditions are utilized by a variety of woodpecker species. In this study I quantified and compared snag density, size, decay characteristics, and excavations in beaver ponds and in forested riparian sites without beaver influence (reference sites) in the western Oregon Cascades. Beaver ponds were treated as a pooled group (n=8) and also categorized into old (n=5) and new (n=3) classes based on decay indicators. Reference sites (n=8) were …

Crystal-Size Distributions And Possible Biogenic Origin Of Fe Sulfides, Mihály Pósfai, Krisztina Cziner, Emö Márton, Péter Márton, Peter R. Buseck, Richard B. Frankel, Dennis A. Bazylinski

Physics

Sedimentary greigite (Fe₃S₄) can form either by ''biologically controlled'' or by ''biologically induced mineralization'' (BCM and BIM, respectively). In order to identify the origin of magnetic Fe sulfides, we studied and compared the sizes and morphologies of greigite crystals produced by a magnetotactic microorganism (previously described and referred to as the ''many-celled magnetotactic prokaryote'', MMP) and Fe sulfides from two specimens of Miocene sedimentary rocks (from Łaka, in the foredeep of the Western Carpathians and from Michalovce, in the Transcarpathian Depression). Greigite grains from the MMP and the Łaka rock show nearly Gaussian crystal-size distributions (CSDs), …

Historical Water-Quality Data For The High Plains Regional Ground-Water Study Area In Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, And Wyoming, 1930–98, David W. Litke

United States Geological Survey: Publications

The High Plains aquifer underlies 174,000 square miles in parts of eight States and includes eight primary hydrogeologic units, including the well-known Ogallala Formation. The High Plains aquifer is an important resource, providing water for 27 percent of the Nation’s irrigated agricul¬tural lands in an otherwise dry landscape. Since the 1980’s there has been concern over the sustainability of the aquifer due to water-level declines caused by substantial pumping. Water quality of the aquifer is a more recent concern. As part of the U.S. Geological Survey’s National Water-Quality Assessment Program, historical water-quality data have been gathered for the High Plains …