Physical Sciences and Mathematics Commons^™

On The Basic Representation Theorem For Convex Domination Of Measures, J. Elton, Theodore P. Hill

Research Scholars in Residence

A direct, constructive proof is given for the basic representation theorem for convex domination of measures. The proof is given in the finitistic case (purely atomic measures with a finite number of atoms), and a simple argument is then given to extend this result to the general case, including both probability measures and finite Borel measures on infinite-dimensional spaces. The infinite-dimensional case follows quickly from the finite-dimensional case with the use of the approximation property.

Magnetic Microstructure Of Magnetotactic Bacteria By Electron Holography, Rafal E. Dunin-Borkowski, Martha R. Mccartney, Richard B. Frankel, Dennis A. Bazylinski, Mihály Pósfai, Peter R. Buseck

Physics

Off-axis electron holography in the transmission electron microscope was used to correlate the physical and magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria. The magnetite crystals were all single magnetic domains, and the magnetization directions of small superparamagnetic crystals were constrained by magnetic interactions with larger crystals in the chains. Shape anisotropy was found to dominate magnetocrystalline anisotropy in elongated crystals. A coercive field between 300 and 450 oersted was determined for one chain.

Half-Cycle Pulse Assisted Electron-Ion Recombination, Thomas J. Bensky, M. B. Campbell, Robert R. Jones

Physics

Unipolar “half-cycle” electric field pulses (HCPs) have been used to recombine free electrons and calcium ions. The field assisted process is very similar to controlled three-body recombination in plasmas. We report on experiments that utilize HCP assisted recombination to probe the probability distribution of continuum electron wave packets and produce bound wave packets that are highly localized in three spatial dimensions.

The Future Of Computing: Cyberspace, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper traces trends in the technological advances of computer and communication systems and examines the promises of the Information Society: global information sharing; and, intelligent decision-support. The technological developments that will lead to the realization of Cyberspace, an information rich environment in which virtual reality capabilities couple directly to the human senses, is explored in terms of five essential components: information processing requirements; communication networks; computing devices (i.e., platforms); hardware and software user-interfaces; and, the meaningful representation of information.

Attention is drawn to the critical role played by information representation in a Cyberspace environment. The author argues …

The Round Table Model: A Web-Oriented, Agent-Based Approach To Decision-Support Applications, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Not unlike King Arthur relying on the infamous Round Table as the setting for consultation with his most trusted experts, agent-based, decision-support systems provide human decision makers with a means of solving complex problems through collaboration with collections of both human and computer-based expert agents. The Round Table Framework provides a formalized architecture together with a set of development and execution tools which can be utilized to design, develop, and execute agent-based, decision-support applications. Based on a three-tier architecture, Round Table incorporates forefront technologies including distributed-object servers, inference engines, and web-based presentation to provide a framework for collaborative, agent-based decision …

Collaborative Decision Support Systems For Facility Management, Arthur J. Chapman, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Agent-based collaborative decision support is a methodology of utilizing domain specific intelligent systems, interacting in a common environment, to partner with one or more human decision makers to reach a consensus solution to a complex problem. An example is the recently developed Collaborative Infrastructure Assessment Tool (CIAT) that provides a collaborative planning facility management tool in support of military pier and port management. This methodology is applicable to many similar dynamic facility management problems where the complexity of issues and the number of decision makers result in the need for domain specific agents, a common view of the data, and …

Electric Potential In The Classical Hall Effect: An Unusual Boundary-Value Problem, Matthew J. Moelter, James Evans, Greg Elliot, Martin Jackson

Physics

The classical Hall effect presents a surprisingly unusual and challenging problem in electrostatics, with boundary conditions that are not of Dirichlet, Neumann, or of mixed Dirichlet and Neumann type. These unusual boundary conditions create several difficulties not normally encountered in standard problems, and ultimately lead to expansion of the electric potential in a nonorthogonal basis set. We derive the boundary conditions for the potential in a rectangular geometry, construct a solution for the potential, and discuss the relation between this problem and problems of the standard mixed type. We also address a commonly encountered misconception about the current distribution.

A Probabilistic Approach To Some Of Euler's Number Theoretic Identities, Don Rawlings

Mathematics

Probabilistic proofs and interpretations are given for the q-binomial theorem, q-binomial series, two of Euler's fundamental partition identities, and for q-analogs of product expansions for the Riemann zeta and Euler phi functions. The underlying processes involve Bernoulli trials with variable probabilities. Also presented are several variations on the classical derangement problem inherent in the distributions considered.

Information Storage Capacity Of Incompletely Connected Associative Memories, Holger Bosch, Franz J. Kurfess

Computer Science and Software Engineering

In this paper, the memory capacity of incompletely connected associative memories is investigated. First, the capacity is derived for memories with fixed parameters. Optimization of the parameters yields a maximum capacity between 0.53 and 0.69 for hetero-association and half of it for auto-association improving previously reported results. The maximum capacity grows with increasing connectivity of the memory and requires sparse input and output patterns. Further, parameters can be chosen in such a way that the information content per pattern asymptotically approaches 1 with growing size of the memory.

Review Of The United States And Arms Control: The Challenge Of Leadership By Allan S. Krass, David W. Hafemeister

Physics

No abstract provided.

Probing Electronic Radial Wave Packets Using Impulsive Momentum Retrieval, M. B. Campbell, Thomas J. Bensky, Robert R. Jones

Physics

Subpicosecond half-cycle pulses and a single-shot imaging detector have been used to monitor the evolution of electronic radial wave packets in calcium. The time-dependent momentum-space probability distribution is obtained using the impulsive momentum retrieval (IMR) method. The measured distributions are compared to the results of quantum and classical simulations allowing a comprehensive evaluation of the benefits and limitations of the IMR method.

Observation Of Oscillations Between Degenerate Bound-State Configurations In Rapidly Autoionizing Two-Electron Atoms, M. B. Campbell, Thomas J. Bensky, Robert R. Jones

Physics

The oscillation between bound-state configurations in a rapidly autoionizing three-body Coulomb system has been directly observed. Using a 500-fsec laser pulse, calcium atoms are excited to the pure 4p_3/215d two-electron configuration at an energy greater than 3 eV above the ionization limit. As a result of configuration interaction, the electrons scatter coherently into multiple bound and continuum configurations. The oscillation between the degenerate 4p_1/2n′d and 4p_3/2nd modes as well as autoionization into 4s_1/2εl, 3d_3/2εl, and 3d_5/2εl …

Preparation Of Gold-Coated Molybdenum Articles And Articles Prepared Thereby, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann

Statistics

A gold-coated molybdenum article (30) is made by furnishing a substrate (32) made of pure molybdenum or an alloy of molybdenum, and preparing a slurry of gold powder, acrylic binder, and acetone liquid carrier. The slurry is applied to a portion of a surface of the substrate. The substrate with applied slurry is heated in vacuum or inert atmosphere to an elevated temperature, preferably about 2040.degree. F., and thereafter cooled to ambient temperature. The result is an article (30) having at least a portion of the substrate (32) covered with an adherent gold coating (34).

Reaction Sequence Of Iron Sulfide Minerals In Bacteria And Their Use As Biomarkers, Mihály Pósfai, Peter R. Buseck, D. A. Bazylinski, Richard B. Frankel

Physics

Some bacteria form intracellular nanometer-scale crystals of greigite (Fe₃S₄) that cause the bacteria to be oriented in magnetic fields. Transmission electron microscope observations showed that ferrimagnetic greigite in these bacteria forms from nonmagnetic mackinawite (tetragonal FeS) and possibly from cubic FeS. These precursors apparently transform into greigite by rearrangement of iron atoms over a period of days to weeks. Neither pyrrhotite nor pyrite was found. These results have implications for the interpretation of the presence of pyrrhotite and greigite in the martian meteorite ALH84001.

Classification Of Hereditary Matrices, Jim Agler, J. W. Helton, Mark Stankus

Mathematics

A classical approach used to obtain basic facts in the theory of square matrices involves an analysis of the relationship between polynomials p in one variable and square matrices T such that p(T) = 0. We consider matrices and operators which satisfy a different type of polynomial constraint. Let H be a complex Hilbert space, T be a bounded linear transformation of H, T* be the adjoint of T, and C[x, y] be the algebra of polynomials in x and y with complex coefficients. For a polynomial p E C[x, y] in …

Intelligent Assistance For Human Supervisory Control Of Multiple Robots, Robin R. Murphy, Erika Rogers

Computer Science and Software Engineering

This paper reviews on-going collaborative efforts between the Colorado School of Mines and Clark-Atlanta University in cooperative assistance for coordination and control of multiple vehicles. It reports on progress in developing an intelligent assistance agent (IAA) for aiding a human operator in diagnosing problems and generating recovery strategies in remote ground robots. The current work has focused on the identification and incorporation of categories of additional information from multiple robots and other agents. These categories are: mission-related sources, such as peer robots working nearby; facility-related sources, such as security cameras; and opportunistically available agents, such as overhead satellites or humans …

Computer Simplification Of Formulas In Linear Systems Theory, J. W. Helton, Mark Stankus, John J. Wavrik

Mathematics

Currently, the three most popular commercial computer algebra systems are Mathematica, Maple, and MACSYMA. These systems provide a wide variety of symbolic computation facilities for commutative algebra and contain implementations of powerful algorithms in that domain. The Gröbner Basis Algorithm, for example, is an important tool used in computation with commutative algebras and in solving systems of polynomial equations.

On the other hand, most of the computation involved in linear control theory is performed on matrices, and these do not commute. A typical issue of IEEE TRANSACTIONS ON AUTOMATIC CONTROL is full of linear systems and computations with their coefficient …

Semi-Permanent Vacuum Closure With Multiple Retubulation Capability, Arthur A. Eneim, Tom K. Evans, Timothy S. Romano, Gary B. Hughes

Statistics

A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough, a hollow tube (62) fixed to the base (50) with a vacuum-tight seal, such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50), and an external thread (58) on the exterior of the base (50). The external thread (58) on the exterior of the base (50) is dimensioned to threadably engage the internal thread …

Constructions Of Random Distributions Via Sequential Barycenters, Theodore P. Hill, Michael Monticino

Research Scholars in Residence

This article introduces and develops a constructive method for generating random probability measures with a prescribed mean or distribution of the means. The method involves sequentially generating an array of barycenters which uniquely defines a probability measure. Basic properties of the generated measures are presented, including conditions under which almost all the generated measures are continuous or almost all are purely discrete or almost all have finite support. Applications are given to models for average-optimal control problems and to experimental approximation of universal constants.

Stand Density Effects On Biomass Allocation Patterns And Subsequent Soil Nitrogen Demand, Christopher Dicus, Thomas J. Dean

Natural Resources Management and Environmental Sciences

Growth and yield data from a loblolly pine plantation in southeastern Louisiana were obtained yearly from 1993 to 1996 on numbered trees within two stands initially planted on a 1.22- by 1.22-meter spacing, and two stands planted on a 2.44- by 2.44-meter spacing. Using allometric equations derived from a 1994 on-site destructive harvest, cited nitrogen concentrations of various tree tissues, and accounting for foliar nitrogen retranslocation, stand growth and soil nitrogen demands were determined. Results showed that production of all aboveground tissues increased as stand density index (SDI) increased. Annual soil nitrogen demand increased with SDI primarily as a result …

Postfire Succession And Disturbance Interactions On An Intermountain Subalpine Spruce-Fir Forest, Michael J. Jenkins, Christopher Dicus, Elizabeth G. Hebertson

Natural Resources Management and Environmental Sciences

Four general postfire successional pathways leading to a climax Engelmann spruce (Picea engelmmlilii Parry)-subalpine fir (Abies /asiocarpa [Hook] Nutt.) forest operate on the T.W. Daniel Experimental Forest in northern Utah. Depending on the successional pathway followed. reestablishment of the prefire climax forest will take 200 to 400 years or more due to a rarity of extreme burning conditions. During the long period between catastrophic stand-replacing fires, a variety of other natural disturbances contribute to the varying structure and composition of vegetation and the fuel mosaic in internountain subalpine spruce-fir forests. Disturbances may range from chronic and small scale …

Restoration Of Mixed Conifer Communities Using Prescribed Fire In Bryce Canyon National Park, Michael J. Jenkins, Christopher Dicus, Joel E. Godfrey

Natural Resources Management and Environmental Sciences

A fire history conducted in the mixed conifer community types of Bryce Canyon National Park found the mean fire-return interval has lengthened from 7.5 to 45 years since 1900. Dendroecology, species, diameter, and age-class analysis showed a change in stand composition in favor of white fir (Abies concolor) and Douglas-fir (Psuedotsuga menziesii) and a 200% increase in fuel accumulation. Recommendations for prescribed burning and mechanical reduction of fuels were incorporated into the Bryce Canyon management plan.

Biological And Management Implications Of Fire-Pathogen Interactions In The Giant Sequoia Ecosystem, Douglas D. Piirto, John R. Parmeter Jr., Fields W. Cobb Jr., Kevin L. Piper, Amy C. Workinger, William J. Otrosina

Natural Resources Management and Environmental Sciences

An overriding management goal for national parks is the maintenance or, where necessary, the restoration of natural ecological processes. In Sequoia-Kings Canyon and Yosemite National Parks, there is concern about the effects of fire suppression on the giant sequoia-mixed conifer forest ecosystem. The National Park Service is currently using prescribed fire management and prescribed burning as tools to reintroduce fire as a natural process. However, there are questions about the positive and negative effects of reintroducing fire in the giant sequoia-mixed conifer ecosystem. Reintroducing fire in the Sierra Nevada forests needs critical evaluation with respect to the pathogens that affect …

An Embedding Of Schwartz Distributions In The Algebra Of Asymptotic Functions, Michael Oberguggenberger, Todor D. Todorov

Mathematics

We present a solution of the problem of multiplication of Schwartz distributions by embedding the space of distributions into a differential algebra of generalized functions, called in the paper "asymptotic function," similar to but different from J. F Colombeau's algebras of new generalized functions.

Ai And The Changing Face Of Health Care, Erika Rogers

Computer Science and Software Engineering

No abstract provided.

Interactive Image Cases For Medical Problem Solving, Erika Rogers, Barb Ericson

Computer Science and Software Engineering

The development of an intelligent assistance agent for diagnostic radiology faces a number of challenges: e.g., how to gain access to the knowledge used an such visual problem solving tasks, how to operationalize it for further processing, and how to present it an the most useful manner for diagnosis. Our previous work an this domain placed an emphasis on the first two issues, and has shown that both perception and problem solving need to be supported an these types of tasks. However, the interface to the underlying intelligence in our first prototypes did not reflect how medical practitioners physically interact …

Vibrational Sum Frequency Spectroscopy Of Surfactants And Phospholipids Monolayers At Liquid-Liquid Interfaces, B. L. Smiley, R. A. Walker, D. E. Gragson, T. E. Hannon, G. L. Richmond

Chemistry and Biochemistry

Work from our laboratory on vibrational sum frequency spectroscopic investigations of molecular ordering at the carbon tetrachloride-water interface is reviewed. Simple charged surfactants adsorbed at the liquid-liquid interface are seen to induce alignment of interfacial water molecules to a degree which is dependent on the induced surface potential. Saturation of water molecule alignment occurs at a surfactant surface concentration corresponding to a calculated surface potential of approximately 160 mV. In complementary studies, the relative degree of hydrocarbon chain ordering within monolayers of symmetric phosphatidylcholines of different chain lengths is inferred by the relative signal contributions of the methyl and methylene …

Single Magnetic Domains In Magnetotactic Bacteria, Richard B. Frankel, Jin-Ping Zhang, Dennis A. Bazylinski

Physics

Magnetotactic bacteria construct an internal, permanent magnetic dipole based on single magnetic domain particles of magnetite or greigite. The organisms exert a high degree of control over the size and morphology of the particles. This may be relevant in distinguishing biogenic from nonbiogenic iron mineral particles.

Review Of The Future Of U.S. Nuclear Weapons Policy, David W. Hafemeister

Physics

No abstract provided.

How Much Reliability And Yield Is Enough For A Ctbt?, David W. Hafemeister

Physics

No abstract provided.