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2001

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Articles 751 - 780 of 3030

Full-Text Articles in Physical Sciences and Mathematics

Data Mining – A Logistics Tool For The 21st Century, Caroline Lubert Jul 2001

Data Mining – A Logistics Tool For The 21st Century, Caroline Lubert

Caroline P Lubert

No abstract provided.


Thermodynamic Model For Surfactant Enhanced Removal Of Organics From Metal Surfaces, Samuel Morton, D. Keffer, R. Counce, D. Depaoli, M. Hu Jul 2001

Thermodynamic Model For Surfactant Enhanced Removal Of Organics From Metal Surfaces, Samuel Morton, D. Keffer, R. Counce, D. Depaoli, M. Hu

Samuel A Morton

No abstract provided.


The Application Of Statistical Analysis Techniques To Reliability, Maintainability & Supportability Data, Caroline Lubert Jul 2001

The Application Of Statistical Analysis Techniques To Reliability, Maintainability & Supportability Data, Caroline Lubert

Caroline P Lubert

No abstract provided.


The Use Of Self-Directed Learning To Promote Active Citizenship In Science, Technology, And Society Classes, Joshua M. Pearce Jul 2001

The Use Of Self-Directed Learning To Promote Active Citizenship In Science, Technology, And Society Classes, Joshua M. Pearce

Joshua M. Pearce

The purpose of this article is to outline the viability of a student-directed assignment within collegiate-level STS curricula for the improvement of the utilization of scientific knowledge and technology in society. The assignment, christened the Do Something! assignment, is a novel teaching tool that utilizes students’ individual interests to encourage in-depth learning across disciplines and capitalizes on their personal skills and talents to solve real-world problems. The Do Something! assignment has been utilized in two STS courses at The Pennsylvania State University (STS 100: The Ascent of Humanity and STS 200: Critical Issues in STS). The structure of this assignment …


The Meaning Of An Information-Centric Computer Environment, Jens G. Pohl Jul 2001

The Meaning Of An Information-Centric Computer Environment, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

It is often lamented that we human beings are suffering from an information overload. This is a myth, as shown in Fig.1 there is no information overload. Instead we are suffering from a data overload. The confusion between data and information is not readily apparent and requires further explanation. Unorganized data are voluminous but of very little value. Over the past 15 years, industry and commerce have made significant efforts to rearrange this unorganized data into purposeful data, utilizing various kinds of database management systems. However, even in this organized form, we are still dealing with data and not information.


University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report First Quarter (March-May 2001), Anthony Hechanova Jul 2001

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report First Quarter (March-May 2001), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) director to the U.S. Department of Energy Office of Nuclear Energy, Science and Technology (DOE-NE) as defined in the UNLV AAA Proposal.

The foundation of the UNLV AAA University Participation Program started as a grassroots effort in the late 1990s among community members and local, state, and federal representatives to encourage research and development of technical alternatives to direct disposal of used nuclear fuel which had been targeted since the early 1980s for Yucca Mountain, Nevada. A …


Comment On "Observation Of Superluminal Behaviors In Wave Propagation", Harry Ringermacher, Lawrence R. Mead Jul 2001

Comment On "Observation Of Superluminal Behaviors In Wave Propagation", Harry Ringermacher, Lawrence R. Mead

Faculty Publications

No abstract provided.


43rd Rocky Mountain Conference On Analytical Chemistry Jul 2001

43rd Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 43rd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 29 - August 2, 2001.


Nocturnal Bird-Avoidance Modeling With Mobile-Marine Radar, Edward J. Zakrajsek, John A. Bissonette Jul 2001

Nocturnal Bird-Avoidance Modeling With Mobile-Marine Radar, Edward J. Zakrajsek, John A. Bissonette

2001 Bird Strike Committee-USA/Canada, Third Joint Annual Meeting, Calgary, AB

To develop a bird-avoidance model for Naval Air Facility El Centro, California, we used a modified marine-radar system to quantify nocturnal (sunset to midnight) bird movements in the area. Previous birdradar studies relied on visual monitoring of the radar screen for data collection. This study represents the first use of computer-aided image analysis of marine-radar bird-data. Radar images were automatically captured, analyzed, and archived with a personal computer. The image analysis eliminated ground clutter, calculated the sample area, identified bird targets, and categorized them into three relative size classes. This made data collection more uniform by eliminating observer bias. We …


A Master-Slave Architecture For Parallel Speaker Recognition, Sunil Kumar Godavarthi Jul 2001

A Master-Slave Architecture For Parallel Speaker Recognition, Sunil Kumar Godavarthi

FIU Electronic Theses and Dissertations

Speaker recognition is one of the popular research interests in speech processing. A speaker recognition system receives the speech signal (data) and determines who the speaker is from a known set of speakers. This process involves the task of matching the input speech signal to the models for all the speakers enrolled in the system. Important factors that determine the success of these systems are response time and accuracy.

The objective of my thesis is to optimize response time by dividing the task of recognition into a number of sub tasks and to execute these individual tasks on load- balanced …


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 Jul 2001

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. …


The Three-Dimensional Random Field Ising Magnet: Interfaces, Scaling, And The Nature Of States, Alan Middleton, Daniel S. Fisher Jul 2001

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 …


Microcavity Surface Emitting Laser, Stewart Feld, John P. Loehr, James A. Lott Jul 2001

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.


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 Jul 2001

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.


School Of Marine Sciences / Darling Marine Center, Kevin J. Eckelbarger Jul 2001

School Of Marine Sciences / Darling Marine Center, Kevin J. Eckelbarger

University of Maine Office of Research Administration: Grant Reports

Over the last six years, the University of Maine has made an unprecedented investment in its marine laboratory, the Darling Marine Center to benefit both University faculty and visiting researchers and their students. Facility improvements include many new laboratory and offices spaces, more research instrumentation, and basic support facilities such as a dining hall and new classrooms. The inauguration of a Visiting Investigation Program in 1991, the expansion of educational offerings, and the growth of a large undergraduate internship program, have resulted in a population explosion that shows no sign of abating. To set priorities for improvements, the University has …


An All Optical Laser Wakefield Electron Injector, Donald P. Umstadter Jul 2001

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 …


Microwave Ionization Of An Atomic Electron Wave Packet, Michael Noel, Lung Ko, T. F. Gallagher Jul 2001

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.


An Analysis Of The South Florida Commuter Assistance Program's Implementation Of Transportation Demand Management Initiatives, Elizabeth Carrera Jul 2001

An Analysis Of The South Florida Commuter Assistance Program's Implementation Of Transportation Demand Management Initiatives, Elizabeth Carrera

FIU Electronic Theses and Dissertations

The purpose of this study was to determine the effectiveness of implementing Transportation Demand Management (TDM) initiatives with the business community by the South Florida Commuter Assistance Program (CAP). To determine this effectiveness, the south Florida CAP was compared with the two other CAPs operating in the state, by analyzing independent evaluations of the program, and by conducting eight individual company case studies.

Independent evaluations of the south Florida CAP for the years 1997 - 2000 were analyzed and found to have increasing trends in the number of companies adopting TDM initiatives. In addition, each case was selected from the …


Structural And Functional Imaging With Carbon Nanotube Afm Probes, J. H. Hafner, Chin Li Cheung, A. T. Woolley, C. M. Lieber Jul 2001

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, …


Measurement And Interpretation Of Deuterium-Line Emission In The Orion Nebula, C. R. O'Dell, Gary J. Ferland, W. J. Henney Jul 2001

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, …


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 Jul 2001

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 Jul 2001

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 …


Improved Hopfield Networks By Training With Noisy Data, Fred Clift, Tony R. Martinez Jul 2001

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 Jul 2001

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 …


Speed Training: Improving The Rate Of Backpropagation Learning Through Stochastic Sample Presentation, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer Jul 2001

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 Jul 2001

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 …


Lazy Training: Improving Backpropagation Learning Through Network Interaction, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer Jul 2001

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 …


Optimal Artificial Neural Network Architecture Selection For Bagging, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer Jul 2001

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.


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. Jul 2001

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 …


Melt Inclusions From Volcan De Colima, Mexico: Complex Examples Of Magmatic Differentiation, Zachary D. Atlas Jul 2001

Melt Inclusions From Volcan De Colima, Mexico: Complex Examples Of Magmatic Differentiation, Zachary D. Atlas

FIU Electronic Theses and Dissertations

Melt inclusions are minute magma bodies trapped within growing crystals. Their chemical compositions are useful in deciphering pre-eruptive conditions and magma evolution. The present study examined melt inclusions trapped in phenocrysts from the 3rd and 4th magmatic cycles (1869-1988) at Volcan de Colima, Mexico. Melt inclusions have highly evolved chemical compositions: 65-77% SiO2, >12% A12O3, 3-6% Na2O and K20 and less than 5.5% Fe and Mg. Major element compositions suggest that they are strongly differentiated magmas controlled by fractionation of plagioclase, opx, cpx and hornblende. Water concentrations were …