Physical Sciences and Mathematics Commons^™

Computer Assistance In Discovering Formulas And Theorems In System Engineering, J. W. Helton, Mark Stankus

Mathematics

If one reads a typical article on A,B,C,D systems in the control transactions, one finds that most of the algebra involved is non commutative rather than commutative. Thus, for symbolic computing to have much impact on linear systems research, one needs a program which will do non-commuting operations. Mathematica, Macsyma and Maple do not. We have a package, NCAlgebra, which runs under Mathematica which does the basic operations, block matrix manipulations and other things. The package might be seen as a competitor to a yellow pad. Like Mathematica the emphasis is on interaction with the program and flexibility.

The issue …

M-Isometric Transformations Of Hilbert Space, I, Jim Alger, Mark Stankus

Mathematics

No abstract provided.

The Anomalous Mössbauer Fraction Of Ferritin And Polysaccharide Iron Complex (Pic), M. E. Y. Mohie-Eldin, Richard B. Frankel, L. Gunther, G. C. Papaefthymiou

Physics

Mössbauer studies of the ubiquitous protein molecule ferritin and its synthetic "biomimic" polysaccharide iron complex (PIC) exhibit an anomaly in the Mössbauer spectrum wherein the recoil free fraction f-factor has a sharp drop with respect to temperature as the temperature rises above 30 K for mammalian ferritin and 60 K for PIC. The anomaly coincides with the disappearance of hyperfine splitting, which is due to superparamagnetic relaxation above the blocking temperature. Different absorbers were used to experimentally investigate the effect of absorber thickness on the Mössbauer spectrum. The anomaly persists for thin absorbers. Also, spectra treated with FFT procedures …

A Statistical Derivation Of The Significant-Digit Law, Theodore P. Hill

Research Scholars in Residence

The history, empirical evidence and classical explanations of the significant-digit (or Benford's) law are reviewed, followed by a summary of recent invariant-measure characterizations. Then a new statistical derivation of the law in the form of a CLT-like theorem for significant digits is presented. If distributions are selected at random (in any "unbiased" way) and random samples are then taken from each of these distributions, the significant digits of the combines sample will converge to the logarithmic (Benford) distribution. This helps explain and predict the appearance of the significant0digit phenomenon in many different empirical contexts and helps justify its recent application …

Intelligent Multimedia Tutoring For Manufacturing Education, Erika Rogers, Yolanda Kennedy, T. Walton, P. Nelms, I. Sherry

Computer Science and Software Engineering

This paper describes current work on the design and implementation of intelligent multimedia tutoring modules which are intended to supplement short training courses in Nondestructive Inspection for the Boeing Defense and Space group.

Multimedia In Manufacturing Education Mime, Chris Thompson, Laurie Hodges, Wayne Daley, Erika Rogers

Computer Science and Software Engineering

This paper describes a project funded by the Technology Reinvestment Project (TRP) under the manufacturing education component (MET) to design, build, and evaluate interactive multimedia courseware for manufacturing education. Interactive multimedia is defined as the combination of computer based text, sound, graphics, animation, video, and simulation, commercial and defense industries along with a professional society are collaborating on the project in an effort to address important dual-use issues. Advanced media technologies are being exploited to create virtual, time shifted, and/or remote visits to real world manufacturing systems. The foundations for our efforts and the experiences in the first year of …

Estimating Time Available For Sensor Fusion Exception Handling, Robin R. Murphy, Erika Rogers

Computer Science and Software Engineering

In previous work, we have developed a generate, test, and debug methodology for detecting, classifying, and responding to sensing failures in autonomous and semi-autonomous mobile robots. An important issue has arisen from these efforts: how much time is there available to classify the cause of the failure and determine an alternative sensing strategy before the robot mission must be terminated?

In this paper, we consider the impact of time for teleoperation applications where a remote robot attempts to autonomously maintain sensing in the presence of failures yet has the option to contact the local for further assistance. Time limits are …

Tunable Picosecond Infrared Laser System Based On Parametric Amplification In Ktp With A Ti:Sapphire Amplifier, D. E. Gragson, D. S. Alavi, G. L. Richmond

Chemistry and Biochemistry

A picosecond laser system that will generate high-power tunable IR pulses with bandwidths suitable for spectroscopic applications is discussed. The system is based on white-light continuum generation in ethylene glycol and optical parametric amplification in potassium titanyl phosphate. The nonlinear-optical processes are driven by a regeneratively amplified Ti:sapphire laser that produces 1.7-ps pulses at a repetition rate of 1 kHz. Energies as high as 40 and 12 µJ have been achieved over the signal (1.02–1.16-µm) and idler (2.6–3.7-µm) tuning ranges, respectively. The IR beam temporal and spatial characteristics are also presented.

Review Of Environmental Physics By Egbert Boeker And Rienk Van Grondelle, David W. Hafemeister

Physics

No abstract provided.

Three-Phase Intersection Points In Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some phospholipid/dihydrocholesterol Langmuir monolayers form coexisting liquid phases. Gas domains form at the interface between the phospholipid-rich and dihydrocholesterol-rich liquid phases when these monolayers undergo expansion to low surface pressure. Analysis of the domain shapes thus formed yields the relative line tensions of the gas/phospholipid, gas/dihydrocholesterol, and phospholipid/dihydrocholesterol phase interfaces.

Remanence Measurements On Individual Magnetotactic Bacteria Using A Pulsed Magnetic Field, Ietje Penninga, Hendrik De Waard, Bruce M. Moskowitz, Dennis A. Bazylinski, Richard B. Frankel

Physics

We describe pulsed-magnetic-field remanence measurements of individual, killed, undisrupted cells of three different types of magnetotactic bacteria. The measurement technique involved the observation of aligned, individual magnetotactic bacteria with a light microscope as they were subjected to magnetic pulses of increasing amplitude. We show that for MM cells, the hysteresis loop is square, with the coercive field variable from cell to cell. This is consistent with just two magnetization states for the single chain of magnetite particles. For MR and MMP cells, the hysteresis loops are not square, indicating that there are several different magnetization states, and that individual cells …

Controlled Biomineralization Of Magnetite (Fe3O4) And Greigite (Fe3S4) In A Magnetotactic Bacterium, Dennis A. Bazylinski, Richard B. Frankel, Brigid R. Heywood, Stephen Mann, John W. King, Percy L. Donaghay, Alfred K. Hanson

Physics

A slowly moving, rod-shaped magnetotactic bacterium was found in relatively large numbers at and below the oxic-anoxic transition zone of a semianaerobic estuarine basin. Unlike all magnetotactic bacteria described to date, cells of this organism produce single-magnetic-domain particles of an iron oxide, magnetite (Fe₃O₄), and an iron sulfide, greigite (Fe₃O₄), within their magnetosomes. The crystals had different morphologies, being arrowhead or tooth shaped for the magnetite particles and roughly rectangular for the greigite particles, and were coorganized within the same chain(s) in the same cell with their long axes along the chain …

Via-Rad: A Blackboard-Based System For Diagnostic Radiology, Erika Rogers

Computer Science and Software Engineering

The work described in this article presents an approach to the integration of computer displayed radiological images with cooperative computerized assistance for decision-making. The VIA-RAD system (Visual Interaction Assistant for Radiology) is a blackboard-based architecture, founded on extensive data collection and analysis in the domain of diagnostic radiology, together with cognitive modeling of the interaction between perception and problem-solving. The details of this system are presented in terms of domain knowledge representation and domain knowledge mapping. A small prototype of the system has been implemented and tested with radiology subjects, and the results of this study are also described.

The Imprudence Of Prudent Avoidance, David W. Hafemeister

Physics

No abstract provided.

Adjacencies In Words, Jean-Marc Fedou, Don Rawlings

Mathematics

Based on two inversion formulas for enumerating words in the free monoid by adjacencies, we present a new approach to a class of permutation problems having Eulerian-type generating functions. We also show that a specialization of one of the inversion formulas gives Diekert's lifting to the free monoid of an inversion theorem due to Cartier and Foata.

Magnetic Force Microscopy Of The Submicron Magnetic Assembly In A Magnetotactic Bacterium, R. B. Proksch, T. E. Schäffer, B. M. Moskowitz, E. D. Dahlberg, Dennis A. Bazylinski, Richard B. Frankel

Physics

A magnetic force microscope (MFM) was used to image topography and magnetic forces from a chain of submicron single magnetic domain particles produced by and contained in isolated magnetotactic bacteria. The noncontact magnetic force microscope data were used to determine a value for the magnetic moment of an individual bacterial cell, of order 10⁻¹³ emu, consistent with the average magnetic moment of bacteria from the same sample, obtained by superconducting quantum interference device magnetometry. The results represent the most sensitive quantification of a magnetic force microscope image to date.

The Significant-Digit Phenomenon, Theodore P. Hill

Research Scholars in Residence

No abstract provided.

Cognitive Cooperation Through Visual Interaction, Erika Rogers

Computer Science and Software Engineering

The purpose of the paper is to describe a cooperative system which was designed to provide intelligent assistance in the domain of diagnostic radiology. The approach taken includes the collection and analysis of human performance data, cognitive modelling of the interaction between perception and problem solving. incorporation of this knowledge into a blackboard-based architecture. implementation of a prototype system and testing and evaluation of the prototype. These stages are described, and then discussed in the context of issues particularly relevant to the study of human-machine cooperation.

Monitoring Nuclear Test Ban Treaties, David W. Hafemeister

Physics

With the end of the Cold War, the emphasis on monitoring nuclear weapons tests has shifted from the 1976 Threshold Test Ban Treaty (TTBT), which confined the US and USSR to a limit of 150 kilotons (kt), to the Comprehensive Test Ban (CTB) Treaty, which would ban all nuclear tests by the signatories. 1995 will be a watershed year to control the proliferation of nuclear weapons, as the Nuclear Non-Proliferation Treaty (NPT) must be considered for renewal. The fate of the NPT is dependent on a successful CTB negotiation, because the two treaties are politically linked. This paper will cover …

Effects Of Imperfect Unipolarity On The Ionization Of Rydberg Atoms By Subpicosecond Half-Cycle Pulses, N. E. Tielking, Thomas J. Bensky, Robert R. Jones

Physics

Rydberg atoms are ionized by nearly unipolar, subpicosecond electromagnetic pulses. Deviations from a perfectly unidirectional pulse are found to alter substantially the ionization probability as a function of peak field. Quantitative agreement between classical theory and experiment is achieved if the pulse imperfections are significantly attenuated.

M-Isometric Transformations Of Hilbert Space, Ii, Jim Alger, Mark Stankus

Mathematics

No abstract provided.

Base-Invariance Implies Benford's Law, Theodore P. Hill

Research Scholars in Residence

A derivation of Benford's Law or the First-Digit Phenomenon is given assuming only base-invariance of the underlying law. The only base-invariant distributions are shown to be convex combinations of two extremal probabilities, one corresponding to point mass and the other a log-Lebesgue measure. The main tools in the proof are identification of an appropriate mantissa σ-algebra on the positive reals, and results for invariant measures on the circle.

Microbes, Magnetism, And Microscopy, E. Dan Dahlberg, R. B. Proksch, Bruce M. Moskowitz, Dennis A. Bazylinski, Richard B. Frankel

Physics

An accurate quantification of magnetic force microscope images has been accomplished. The magnetosomes produced by magnetotactic bacteria, an ideal micromagnetic model system, were the specimens used for the quantification (a moment on the order of 10⁻¹³ emu).

Geomorphic And Pedogenic Evolution In Coastal Sediments, Central California, Lynn E. Moody, R. C. Graham

Natural Resources Management and Environmental Sciences

Studies of soil chronosequences on marine terraces facilitate the use of terraces for tectonic and paleoclimatic interpretation. However, many areas on the California coast have received substantial eolian deposits after pedogenesis began, so do not qualify as chronosequences. These areas are worthy of study because they are widespread coastal landscape features, and they enable us to interpret pedogenic and geomorphic processes in sandy regolith. The objective of this study was to use soil and deep regolith morphology and chemistry to interpret pedogenic and geomorphic evolution on a sequence of four marine terraces, San Luis Obispo County, California. The terraces are …

A Cognitive Theory Of Visual Interaction, Erika Rogers

Computer Science and Software Engineering

No abstract provided.

Knowledge-Based Image Enhancement For Cooperative Tele-Assistance, Erika Rogers, Versonya Dupont, Robin R. Murphy, Nazir Warsi

Computer Science and Software Engineering

There is an increasing need in complex environments for computerized assistance, both for the effective filtering and display of pertinent information or data, and also for the decision-making task itself. The combination of artificial intelligence techniques with image processing and graphics capabilities provides the foundation for building intelligent systems which act as mediaries between the human and the task domain. In the field of tele-assistance, this type of system enables cooperative problem-solving between a remote semi-autonomous robot and a local human supervisor. This paper describes current work on such a system, with an emphasis on the development of knowledge-based image …

Cooperative Assistance For Remote Robot Supervision, Erika Rogers, Robin R. Murphy, A. Stewart, Nazir Warsi

Computer Science and Software Engineering

This paper describes current work on the design of a computer system which provides cooperative assistance for the supervision of remote semi-autonomous robots. It consists of a blackboard-based framework which allows communication between the remote robot, the local human supervisor, and an intelligent mediating system, which aids interactive exception handling when the remote robot requires the assistance of the local operator.

Structure And Function Of Magnetosomes In Magnetotactic Bateria, Richard B. Frankel, Dennis A. Bazylinski

Physics

Magnetotactic bacteria contain magnetosomes, which are mineral particles enclosed my membranes. The particles are ferrimagnetic magnetite, ferrimagnetic greigite, or greigite and non-magnetic pyrite. The particles constitute an elegant biomagnetic compass that orients the cell along the geomagnetic field lines as it swims. This paper discusses the structures of these particles and their possible formation mechanisms.