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Full-Text Articles in Physical Sciences and Mathematics

Higher Twist Contributions To R-Hadron Phenomenology In The Light Gluino Scenario, Thomas D. Gutierrez, R. Vogt, J. F. Gunion Dec 2000

Higher Twist Contributions To R-Hadron Phenomenology In The Light Gluino Scenario, Thomas D. Gutierrez, R. Vogt, J. F. Gunion

Physics

The open light gluino window allows non-trivial higher-twist gluino contributions to the proton wave function. Using a two-component model originally developed for charm hadroproduction, higher-twist intrinsic gluino contributions to final-state R-hadron formation are shown to enhance leading-twist production in the forward xnF region. We calculate R-hadron production at Pnlab=800 GeV in pp, pBe, and pCu interactions with light gluino masses of 1.2, 1.5, 3.5, and 5.0 GeV.


Electrical Feedthrough And Its Preparation, Leonard E. Peck, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann Dec 2000

Electrical Feedthrough And Its Preparation, Leonard E. Peck, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann

Statistics

An electrical feedthrough (34) is prepared by furnishing an aluminum oxide feedthrough plate (70) and at least one feedthrough pin (80) having a length greater than the thickness of the feedthrough plate (70). A pin bore (78) is formed through the feedthrough plate (70) for each feedthrough pin (80). Each pin bore (78) has a pin bore (78) size greater than the feedthrough pin (80) size, preferably by an amount no greater than that required to permit the penetration of a brazing metal (88) between the pin bore (78) and the feedthrough pin (80). Each feedthrough pin (80) is inserted …


Seaway: A Multi-Agent Decision-Support System For Naval Expeditionary Logistic Operations, Anthony Wood, Kym Jason Pohl, Justin Crawford, Mark Lai, John Fanshier, Ken Cudworth, Tom Tate, Hisham Assal, Shawn Pan, Jens G. Pohl Dec 2000

Seaway: A Multi-Agent Decision-Support System For Naval Expeditionary Logistic Operations, Anthony Wood, Kym Jason Pohl, Justin Crawford, Mark Lai, John Fanshier, Ken Cudworth, Tom Tate, Hisham Assal, Shawn Pan, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This report describes work performed by CDM Technologies Inc. in conjunction with the Collaborative Agent Design (CAD) Research Center of California Polytechnic State University (Cal Poly), San Luis Obispo, for the Office of Naval Research (ONR), on the SEAWAY experimental system for planning, gaming and executing maritime logistic operations from a sea base. SEAWAY incorporates three fundamental concepts that distinguish it from existing (i.e., legacy) command and control applications. First, it is a collaborative system in which computer-based agents assist human operators by monitoring, analyzing and reasoning about events in near real-time. Second, SEAWAY includes an ontological model of the …


A Discotic Disguised As A Smectic: A Hybrid Columnar Bragg Glass, Karl Saunders, Leo Radzihovsky, John Toner Nov 2000

A Discotic Disguised As A Smectic: A Hybrid Columnar Bragg Glass, Karl Saunders, Leo Radzihovsky, John Toner

Physics

We show that discotics, lying deep in the columnar phase, can exhibit an x-ray scattering pattern which mimics that of a somewhat unusual smectic liquid crystal. This exotic, new glassy phase of columnar liquid crystals, which we call a “hybrid columnar Bragg glass,” can be achieved by confining a columnar liquid crystal in an anisotropic random environment of, e.g., strained aerogel. Long-ranged orientational order in this phase makes single-domain x-ray scattering possible, from which a wealth of information could be extracted. We give detailed quantitative predictions for the scattering pattern in addition to exponents characterizing anomalous elasticity of the system.


Two-Dimensional Pendulum Experiments Using A Spark Generator, Rand S. Worland, Matthew J. Moelter Nov 2000

Two-Dimensional Pendulum Experiments Using A Spark Generator, Rand S. Worland, Matthew J. Moelter

Physics

Student understanding of the superposition of perpendicular harmonic oscillators can be enhanced using a spark generator to record position-versus-time data for smallamplitude pendulum motion in two dimensions. Our students have used this arrangement to analyze the motion of a spherical pendulum and a “Y-suspended” (Blackburn) pendulum that has two effective lengths.


Immaccs: An Experimental Multi-Agent C2 System, Jens G. Pohl, Anthony A. Wood, Kym Jason Pohl Oct 2000

Immaccs: An Experimental Multi-Agent C2 System, Jens G. Pohl, Anthony A. Wood, Kym Jason Pohl

Collaborative Agent Design (CAD) Research Center

The Integrated Marine Multi-Agent Command and Control System (IMMACCS) is a multi-agent, distributed software system, designed to provide a Common Tactical Picture (CTP) with integrated and meaningful decision-support facilities to authorized operators at any access node. IMMACCS has been implemented as a three-tier architecture that distinguishes between information, logic and presentation. It utilizes an object-serving communication facility with subscription and multi-casting capabilities that is based on the Common Object Request Broker Architecture (CORBA). With an emphasis on application, IMMACCS was designed and implemented in concert with its military users as an integral component of experiments conceived by the Marine Corps …


Semi-Regular Mesh Extraction From Volumes, Z. J. Wood, M. Desbrun, P. Schroder, D. Breen Oct 2000

Semi-Regular Mesh Extraction From Volumes, Z. J. Wood, M. Desbrun, P. Schroder, D. Breen

Computer Science and Software Engineering

We present a novel method to extract iso-surfaces from distance volumes. It generates high quality semi-regular multiresolution meshes of arbitrary topology. Our technique proceeds in two stages. First, a very coarse mesh with guaranteed topology is extracted. Subsequently an iterative multi-scale force-based solver refines the initial mesh into a semi-regular mesh with geometrically adaptive sampling rate and good aspect ratio triangles. The coarse mesh extraction is performed using a new approach we call surface wavefront propagation. A set of discrete iso-distance ribbons are rapidly built and connected while respecting the topology of the iso-surface implied by the data. Subsequent multi-scale …


Robotic System Sensitivity To Neural Network Learning Rate: Theory, Simulation, And Experiments, Christopher M. Clark, James K. Mills Oct 2000

Robotic System Sensitivity To Neural Network Learning Rate: Theory, Simulation, And Experiments, Christopher M. Clark, James K. Mills

Computer Science and Software Engineering

Selection of neural network learning rates to obtain satisfactory performance from neural network controllers is a challenging problem. To assist in the selection of learning rates, this paper investigates robotic system sensitivity to neural network (NN) learning rate. The work reported here consists of experimental and simulation results. A neural network controller module, developed for the purpose of experimental evaluation of neural network controller performance of a CRS Robotics Corporation A460 robot, allows testing of NN controllers using real-time iterative learning. The A460 is equipped with a joint position proportional, integral, and derivative (PID) controller. The neural network module supplies …


Using A Mensuration Approach With Fia Vegetation Plot Data To Assess The Accuracy Of Tree Size And Crown Closure Classes In A Vegetation Map Of Northeastern California, Samantha J. Gill, Jeff Milliken, Debby Beardsley, Ralph Warbington Sep 2000

Using A Mensuration Approach With Fia Vegetation Plot Data To Assess The Accuracy Of Tree Size And Crown Closure Classes In A Vegetation Map Of Northeastern California, Samantha J. Gill, Jeff Milliken, Debby Beardsley, Ralph Warbington

Natural Resources Management and Environmental Sciences

The accuracy of the Lassen-Modoc vegetation map was assessed using data from a grid of permanent Forest In-ventory and Analysis (FIA) plots in conjunction with a fuzzy logic approach. This paper presents the results for the Modoc National Forest. The main foci of this paper are the methods and results for assessing the accuracy of tree size and crown closure classes using a mensurational approach based on calculations made from the plot data. This approach proved very useful in conjunction with fuzzy accuracy methods. Higher error rates reported for crown closure classes may be due to a variety of factors …


Singularly Perturbed Control Systems Using Non-Commutative Computer Algebra, J. W. Helton, F. Dell Kronewitter, W. M. Mceneaney, Mark Stankus Sep 2000

Singularly Perturbed Control Systems Using Non-Commutative Computer Algebra, J. W. Helton, F. Dell Kronewitter, W. M. Mceneaney, Mark Stankus

Mathematics

Most algebraic calculations which one sees in linear systems theory, for example in IEEE TAC, involve block matrices and so are highly non-commutative. Thus conventional commutative computer algebra packages, as in Mathematica and Maple, do not address them. Here we investigate the usefulness of non-commutative computer algebra in a particular area of control theory − singularly perturbed dynamic systems − where working with the non-commutative polynomials involved is especially tedious. Our conclusion is that they have considerable potential for helping practitioners with such computations. Commutative Gröbner basis algorithms are powerful and make up the engines in symbolic algebra packages' …


Occurrence And Distribution Of Diverse Populations Of Magnetic Protists In A Chemically Stratified Coastal Salt Pond, Dennis A. Bazylinski, David R. Schlezinger, Brian H. Howes, Richard B. Frankel, Slava S. Epstein Sep 2000

Occurrence And Distribution Of Diverse Populations Of Magnetic Protists In A Chemically Stratified Coastal Salt Pond, Dennis A. Bazylinski, David R. Schlezinger, Brian H. Howes, Richard B. Frankel, Slava S. Epstein

Physics

Chemical stratification occurs in the water columns and sediments of many aquatic habitats resulting in vertical chemical and redox gradients. Various types of microorganisms are often associated with specific depths and chemical parameters in these situations. For example, magnetite-producing magnetotactic bacteria are known to form horizontal “plates” of cells at the oxic/anoxic transition zone (OATZ) of such environments. Here, we report the presence of populations of diverse magnetic protists in a seasonally chemically stratified, coastal salt pond. The protistan types included several biflagellates, a dinoflagellate, and a ciliate that were each associated with specific depths and thus, specific chemical, microbiological …


Adapting To The Information Age, Jens G. Pohl Jul 2000

Adapting To The Information Age, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper draws attention to the profound changes that human civilization is experiencing as it moves from an industrial environment into an information environment, in which unprecedented emphasis is placed on the knowledge and capabilities of the individual. A clear distinction is drawn between data and information in relationship to computer-based facilities, and the transition of data-processing to the higher levels of information and knowledge representation in quasi intelligent decision-support systems. It is argued that the cultivation of its human capital becomes a foundational requirement for the success of a knowledge-based organization. In such an organization traditional practices of hierarchical, …


An Inference Engine-Based Subscription Service, Kym J. Pohl, Jens G. Pohl Jul 2000

An Inference Engine-Based Subscription Service, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

A Distributed Network Architecture (DNA) forms the basis of many decision-support systems available today. Such architecture excels at providing an application environment rich in transparency, performance, and expandability (Gray and Lievano 1997). However, efforts at the Collaborative Agent Design (CAD) Research Center in San Luis Obispo, California have found that for this architecture to be successfully applied to agent-based, decision-support systems two additional ingredients must be present, namely a query service and a subscription service. These two mechanisms support the extensive collaboration inherent in agent-based, decision-support systems. Although primarily utilized as a means of agent-to-agent interaction these two services can …


Modelling The Dynamics Of Abyssal Equator-Crossing Currents, P. F. Choboter, G. E. Swaters Jul 2000

Modelling The Dynamics Of Abyssal Equator-Crossing Currents, P. F. Choboter, G. E. Swaters

Mathematics

No abstract provided.


Peak Flow Responses To Forest Practices In The Western Cascades Of Oregon, Usa, R. L. Beschta, M. R. Pyles, A. E. Skaugset, C. G. Surfleet Jun 2000

Peak Flow Responses To Forest Practices In The Western Cascades Of Oregon, Usa, R. L. Beschta, M. R. Pyles, A. E. Skaugset, C. G. Surfleet

Natural Resources Management and Environmental Sciences

The effects of clearcut silviculture (road building, clearfelling, cable logging, and site preparation) were evaluated using long-term peakflow records for three small watersheds (60–101 ha) and six large basins (62–640 km2) in the western Cascades of Oregon, USA. After a calibration period, two of the small watersheds were treated while the third remained untreated (control). Analysis indicated that peakflow increases following treatments were dependent upon peakflow magnitude. Peakflow increases averaged approximately 13–16% after treatment for 1-yr recurrence interval events, and 6–9% for 5-yr recurrence interval events. For the six large basins, multiple linear regression analyses of peakflows relative …


Restricted Words By Adjacencies, Don Rawlings Jun 2000

Restricted Words By Adjacencies, Don Rawlings

Mathematics

A recurrence, a determinant formula, and generating functions are presented for enumerating words with restricted letters by adjacencies. The main theorem leads to refinements (with up to two additional parameters) of known results on compositions, polyominoes, and permutations. Among the examples considered are (1) the introduction of the ascent variation on compositions, (2) the enumeration of directed vertically convex polyominoes by upper descents, area, perimeter, relative height, and column number, (3) a tri-variate extension of MacMahon's determinant formula for permutations with prescribed descent set, and (4) a combinatorial setting for an entire sequence of bibasic Bessel functions.


The Poisson Variation Of Montmort's Matching Problem, Don Rawlings Jun 2000

The Poisson Variation Of Montmort's Matching Problem, Don Rawlings

Mathematics

No abstract provided.


Hybrid Probabilistic Programs, Alex Dekhtyar, V. S. Subrahmanian Jun 2000

Hybrid Probabilistic Programs, Alex Dekhtyar, V. S. Subrahmanian

Computer Science and Software Engineering

The precise probability of a compound event (e.g. e1 V e2,e1 Ʌ e2) depends upon the known relationships (e.g. independence, mutual exclusion, ignorance of any relationship, etc.) between the primitive events that constitute the compound event. To date, most research on probabilistic logic programming has assumed that we are ignorant of the relationship between primitive events. Likewise, most research in AI (e.g. Bayesian approaches) has assumed that primitive events are independent. In this paper, we propose a hybrid probabilistic logic programming language in which the user can explicitly associate, with any given probabilistic strategy, a conjunction and disjunction operator, and …


Proceedings Of The 2000 Onr Decision-Support Workshop Series: The Human-Computer Partnership In Decision-Support, Collaborative Agent Design Research Center May 2000

Proceedings Of The 2000 Onr Decision-Support Workshop Series: The Human-Computer Partnership In Decision-Support, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

The Decision Support Workshop of May 2-4, 2000 held in San Luis Obispo, Cal., was the second in a series that was started one year earlier as a joint project of the Office of Naval Research and the Collaborative Agent Design Research Center of Cal Poly.

The goal of this series of Workshops is to provide a forum where connections can be established on one hand between developers and proponents of decision support tools, with potential users such as managers of large, complex organizations/systems on the other. Clearly, the military belong to this class of users and it is therefore …


Doomsday Fears At Rhic, Thomas D. Gutierrez May 2000

Doomsday Fears At Rhic, Thomas D. Gutierrez

Physics

This year, the Relativistic Heavy Ion Collider (RHIC) is poised to begin a program of cutting-edge nuclear science. Recently, alarmist journalism unnecessarily raised public fears about implausible doomsday scenarios associated with the machine.


Monitoring Of Distributed Processes With Mobile Agents, Ryan P. Kennedy, Franz J. Kurfess Apr 2000

Monitoring Of Distributed Processes With Mobile Agents, Ryan P. Kennedy, Franz J. Kurfess

Computer Science and Software Engineering

The proliferation of networked and distributed systems presents a need for more tool development with regard to the monitoring and maintenance of distributed processes. The goal of this paper is to present a mechanism used to collect detailed process information from various remote Unix hosts on a network. The interface to this mechanism, a GUI applet, is accessible through a Java enabled browser such as Netscape Navigator. It presents the user with a menu of choices such as which host to view, and what process information to retrieve (I/O-bound processes, numbers of processes, individual/total process usage, etc.). The requested information …


Magnetite Biomineralization And Ancient Life On Mars, Richard B. Frankel, Peter R. Buseck Apr 2000

Magnetite Biomineralization And Ancient Life On Mars, Richard B. Frankel, Peter R. Buseck

Physics

Certain chemical and mineral features of the Martian meteorite ALH84001 were reported in 1996 to be probable evidence of ancient life on Mars. In spite of new observations and interpretations, the question of ancient life on Mars remains unresolved. Putative biogenic, nanometer magnetite has now become a leading focus in the debate.


Topologically Ordered Phases Of Smectics Confined In Anisotropic Random Media: Smectic Bragg Glasses, Karl Saunders, Brad Jacobsen, Leo Radzihovsky, John Toner Feb 2000

Topologically Ordered Phases Of Smectics Confined In Anisotropic Random Media: Smectic Bragg Glasses, Karl Saunders, Brad Jacobsen, Leo Radzihovsky, John Toner

Physics

We report the existence of two new topologically ordered glass phases of smectics in strained aerogel. In contrast to the case of unstrained aerogel, we find compelling theoretical arguments that a smectic in uniaxially stretched aerogel exhibits, for homeotropic nematic-aerogel alignment, a `smectic Bragg glass' in the universality class of the `XY Bragg glass'. On the other hand, a uniaxial compression, with homeotropic alignment, leads to an entirely novel type of anisotropic smectic elastic glass phase that we call the `m = 1 Bragg glass'. This latter phase exhibits anomalous elasticity, characterized by exponents that we calculate to high precision. …


Modeling Conifer Tree Crown Radius And Estimating Canopy Cover, Samantha J. Gill, Gregory S. Biging, Edward C. Murphy Feb 2000

Modeling Conifer Tree Crown Radius And Estimating Canopy Cover, Samantha J. Gill, Gregory S. Biging, Edward C. Murphy

Natural Resources Management and Environmental Sciences

Models of tree crown radius were developed for several conifer species of California. Typical forest inventory variables (DBH, height, height-to-crown base, crown class, basal area per hectare, and trees per hectare) were considered as independent variables in model development. Models were fitted using both ordinary and weighted least squares methods. It was found that for the species studied, an ordinary least squares linear regression with DBH as the only independent variable was appropriate. For some species studied, the addition of other independent variables provided minor improvements over the model with only DBH. These models of crown radius could be summed …


Branch Transition Rate: A New Metric For Improved Branch Classification Analysis, Michael Haungs, Phil Sallee, Matthew Farrens Jan 2000

Branch Transition Rate: A New Metric For Improved Branch Classification Analysis, Michael Haungs, Phil Sallee, Matthew Farrens

Computer Science and Software Engineering

Recent studies have shown significantly improved branch prediction through the use of branch classification. By separating static branches into groups, or classes, with similar dynamic behavior, predictors may be selected that are best suited for each class. Previous methods have classified branches according to taken rate (or bias). We propose a new metric for branch classification: branch transition rate, which is defined as the number of times a branch changes direction between taken and not taken during execution. We show that transition rate is a more appropriate indicator of branch behavior than taken rate for determining predictor performance. When both …


Extensive Forest Leaf Area Survey Aiming At Detection Of Vegetation Change In Subarctic-Boreal Zone, Tomoko Kusakabe, Hayato Tsuzuki, Gary B. Hughes, Tatsuo Sweda Jan 2000

Extensive Forest Leaf Area Survey Aiming At Detection Of Vegetation Change In Subarctic-Boreal Zone, Tomoko Kusakabe, Hayato Tsuzuki, Gary B. Hughes, Tatsuo Sweda

Statistics

The warming resulting from increasing anthropogenic carbon dioxide and other greenhouse gasses is expected to be most prominent in the subarctic-boreal region of the Northern Hemisphere. With the objective of setting up a baseline to monitor possible vegetation change in this region, a continuous vegetation profile extending 600 km from Edmonton, Alberta to Cluff Lake, Saskatchewan, Canada was measured using an airborne infrared laser altimeter mounted on a helicopter. Then the distribution of leaf area index over the same 600 km long transect was estimated from this vegetation profile based on a series of plot surveys on the ground to …


On The Baroclinic Instability Of Axisymmetric Rotating Gravity Currents With Bottom Slope, Paul F. Choboter, Gordone E. Swaters Jan 2000

On The Baroclinic Instability Of Axisymmetric Rotating Gravity Currents With Bottom Slope, Paul F. Choboter, Gordone E. Swaters

Mathematics

The baroclinic stability characteristics of axisymmetric gravity currents in a rotating system with a sloping bottom are determined. Laboratory studies have shown that a relatively dense fluid released under an ambient fluid in a rotating system will quickly respond to Coriolis effects and settle to a state of geostrophic balance. Here we employ a subinertial two-layer model derived from the shallow-water equations to study the stability characteristics of such a current after the stage at which geostrophy is attained. In the model, the dynamics of the lower layer are geostrophic to leading order, but not quasi-geostrophic, since the height deflections …


Nonstandard Analysis In Topology: Nonstandard And Standard Compactifications, S. Salbany, Todor D. Todorov Jan 2000

Nonstandard Analysis In Topology: Nonstandard And Standard Compactifications, S. Salbany, Todor D. Todorov

Mathematics

Let (X, T) be a topological space, and X a non–standard extension of X. There is a natural “standard” topology ST on X generated by G,where G ∈ T . The topological space (X,ST) will be used to study, in a systematic way, compactifications of (X, T).


Neural Networks And Structured Knowledge: Rule Extraction And Applications, Franz J. Kurfess Jan 2000

Neural Networks And Structured Knowledge: Rule Extraction And Applications, Franz J. Kurfess

Computer Science and Software Engineering

As the second part of a special issue on "Neural Networks and Structured Knowledge," the contributions collected here concentrate on the extraction of knowledge, particularly in the form of rules, from neural networks, and on applications relying on the representation and processing of structured knowledge by neural networks. The transformation of the low-level internal representation in a neural network into higher-level knowledge or information that can be interpreted more easily by humans and integrated with symbol-oriented mechanisms is the subject of the first group of papers. The second group of papers uses specific applications as starting point, and describes approaches …


Instructional Design Agents – An Integration Of Artificial Intelligence And Educational Technology, Erika Rogers, Carol Scheftic, Emilio Passi, Sharon Lanaghan Jan 2000

Instructional Design Agents – An Integration Of Artificial Intelligence And Educational Technology, Erika Rogers, Carol Scheftic, Emilio Passi, Sharon Lanaghan

Computer Science and Software Engineering

The purpose of this paper is to introduce a project whose goal is to design and develop a productivity tool which helps academic instructors in their course preparation. This tool will be composed of a number of “instructional design agents”, which combine techniques in human-computer interaction, artificial intelligence and educational theory. The first of these agents is based on Bloom’s Taxonomy, and a brief overview of this work in progress is presented.