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California Polytechnic State University, San Luis Obispo

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Articles 2191 - 2220 of 2553

Full-Text Articles in Physical Sciences and Mathematics

Interactive Image Cases For Medical Problem Solving, Erika Rogers, Barb Ericson Jan 1998

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 …

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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 Jan 1998

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 …

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Single Magnetic Domains In Magnetotactic Bacteria, Richard B. Frankel, Jin-Ping Zhang, Dennis A. Bazylinski Jan 1998

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.

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Review Of The Future Of U.S. Nuclear Weapons Policy, David W. Hafemeister Jan 1998

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

Physics

No abstract provided.

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Biomineralization Of Magnetic Iron Minerals In Bacteria, Richard B. Frankel, Dennis A. Bazylinski, Dirk Schϋler Jan 1998

Biomineralization Of Magnetic Iron Minerals In Bacteria, Richard B. Frankel, Dennis A. Bazylinski, Dirk Schϋler

Physics

Magnetotactic bacteria orient and migrate along magnetic field lines. This ability is based on a submicron assembly of single-magnetic domain iron mineral particles that elegantly solves the problem of how to construct a magnetic dipole that is large enough to be oriented in the geomagnetic field at ambient temperature, yet fit inside a micron-sized cell. The solution is based on the ability of the bacteria to accumulate high concentrations of iron, and control the deposition, size and orientation of a specific iron mineral at specific locations in the cell.

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How Much Reliability And Yield Is Enough For A Ctbt?, David W. Hafemeister Jan 1998

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

Physics

No abstract provided.

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Probing The Intermolecular Hydrogen Bonding Of Water Molecules At The Ccl4/Water Interface In The Presence Of Charges Soluble Surfactant, D. E. Gragson, G. L. Richmond Dec 1997

Probing The Intermolecular Hydrogen Bonding Of Water Molecules At The Ccl4/Water Interface In The Presence Of Charges Soluble Surfactant, D. E. Gragson, G. L. Richmond

Chemistry and Biochemistry

The molecular structure and hydrogen bonding of water molecules at the CCl4/water interface in the presence of a charged soluble surfactant has been explored in this study using vibrational sum frequency generation. By examining OH stretching modes that are highly sensitive to the local hydrogen bonding environment it is found that water molecules at the CCl4/water interface both in the presence and absence of a charged soluble surfactant are predominantly in a tetrahedral arrangement much like the structure ofice. Isotopic dilution studies have been employed to further characterize this icelike interfacial structure. Ablueshift ofapproximately120 cm-1 …

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"Hands-On" Epicycles And Retrograde Motion, Matthew J. Moelter, Bernard A. Bates Dec 1997

"Hands-On" Epicycles And Retrograde Motion, Matthew J. Moelter, Bernard A. Bates

Physics

No abstract provided.

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Hands-On Phasors And Multiple-Slit Interference, Rand S. Worland, Matthew J. Moelter Nov 1997

Hands-On Phasors And Multiple-Slit Interference, Rand S. Worland, Matthew J. Moelter

Physics

No abstract provided.

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Reaction Of Dioxygen With A Cross-Conjugated Carbon-Carbon Double Bond In A Bis-Macrocycle Diiron Compound, D. Brent Macqueen, Christopher Lange, Melvin Calvin, John W. Otvos, Larry O. Spreer, Christian B. Allan, Anna Ganse, Richard B. Frankel Oct 1997

Reaction Of Dioxygen With A Cross-Conjugated Carbon-Carbon Double Bond In A Bis-Macrocycle Diiron Compound, D. Brent Macqueen, Christopher Lange, Melvin Calvin, John W. Otvos, Larry O. Spreer, Christian B. Allan, Anna Ganse, Richard B. Frankel

Physics

Dioxygen at atmospheric pressure attacks a cross-conjugated carbon-carbon double bond in a diiron complex to form two, like, keto macrocyclic iron(II) complexes. This reaction occurs with high yield in both solution and in the solid state. A dioxetane intermediate is, therefore, invoked. The rate of the reaction is very dependent on the nature of the axial ligands on the low-spin iron(II) ions in the bimetallic complex. The rate is at least a factor of 104 faster with DMF ligands than with CH3CN axial ligands. This rate dependence is explained by stabilization of a peroxo biradical transition state …

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The Impact Of Multimedia Training On Mental Models Of Simple Processes, Johnny L. Washington, Erika Rogers Oct 1997

The Impact Of Multimedia Training On Mental Models Of Simple Processes, Johnny L. Washington, Erika Rogers

Computer Science and Software Engineering

The purpose of this paper is to describe work in progress on a project which is designed to study how multimedia training may impact people’s mental models of sample processes. A tutorial is under development which helps people learn how to construct an abstract model of the steps needed to produce a letter on a typewriter, and how to change this model when the task moues to a computerized setting. Subjects have been recruited to participate in this study, and the current status of the project is discussed.

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Outbreak Agent: Intelligent Wearable Technology For Hazardous Environments, Erika Rogers, Robin R. Murphy, Chris Thompson Oct 1997

Outbreak Agent: Intelligent Wearable Technology For Hazardous Environments, Erika Rogers, Robin R. Murphy, Chris Thompson

Computer Science and Software Engineering

The topic of this paper is a project to design an intelligent agent which supports humans in the domain of hazardous site investigation. This software agent will be integrated into wearable technology which is embedded in the protective clothing worn by the humans. An overview of some of the design issues is presented, with a particular emphasis on the visual problem solving component.

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Determination Of The Preexponential Frequency Factor For Superparamagnetic Maghemite Particles In Magnetoferritin, Bruce M. Moskowitz, Richard B. Frankel, Sarah A. Walton, Dominic P. E. Dickson, K. K. W. Wong, T. Douglas, Stephen Mann Oct 1997

Determination Of The Preexponential Frequency Factor For Superparamagnetic Maghemite Particles In Magnetoferritin, Bruce M. Moskowitz, Richard B. Frankel, Sarah A. Walton, Dominic P. E. Dickson, K. K. W. Wong, T. Douglas, Stephen Mann

Physics

Magnetization and Mössbauer measurements on maghemite particles with an average particle diameter of 10 nm have been made in the temperature range from 5 K to 353 K spanning the superparamagnetic (SPM) and stable single domain (SD) regimes. The maghemite particles were produced within the iron-storage protein ferritin, resulting in a narrowly-sized, weakly interacting nanocomposite material called magnetoferritin. Experiments combining hysteresis measurements, low temperature remanence, and Mössbauer spectroscopy were used to characterize magnetoferritin and to provide experimental estimates of (1) the pre-exponential frequency factor ƒ0 in the Néel-Arhennius relaxation equation; (2) the SPM threshold size at room temperature for …

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Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell Oct 1997

Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some binary lipid mixtures form coexisting liquid phases when spread at the air/water interface. This work describes the pressure–composition phase diagrams of binary mixtures of four unsaturated phosphatidylcholines with dihydrocholesterol. These four binary mixtures have critical compositions of approximately fifty mole percent, and average critical exponents of 0.25±0.07. The data can also be approximated by a regular solution thermodynamic model, yielding parameters for the non-ideality of these mixtures.

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Orbifolds With Lower Ricci Curvature Bounds, Joseph E. Borzellino Oct 1997

Orbifolds With Lower Ricci Curvature Bounds, Joseph E. Borzellino

Mathematics

We show that the first betti number of a compact Riemannian orbifold with Ricci curvature and diameter is bounded above by a constant , depending only on dimension, curvature and diameter. In the case when the orbifold has nonnegative Ricci curvature, we show that the is bounded above by the dimension , and that if, in addition, , then is a flat torus .

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Single-Shot Detection Of Wavepacket Evolution, M. B. Campbell, Thomas J. Bensky, Robert R. Jones Sep 1997

Single-Shot Detection Of Wavepacket Evolution, M. B. Campbell, Thomas J. Bensky, Robert R. Jones

Physics

We have developed a new instrument for monitoring electronic wavepacket dynamics using a single electromagnetic pulse pair. The operation of the device is analogous to that of single-shot cross-correlators commonly used to monitor the temporal evolution of short laser pulses. We have used the instrument to probe wavepacket evolution over time scales ranging from 100 psec to less than 1 fsec. The device reduces the amount of time required to collect pump-probe time delay data by orders of magnitude, greatly reducing the deleterious effects of experimental drifts. In addition, the single-shot feature provides real-time feedback as to the affect of …

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Ionization Of Na Rydberg Atoms By Subpicosecond Quarter-Cycle Circularly Polarized Pulses, Thomas J. Bensky, G. Haeffler, Robert R. Jones Sep 1997

Ionization Of Na Rydberg Atoms By Subpicosecond Quarter-Cycle Circularly Polarized Pulses, Thomas J. Bensky, G. Haeffler, Robert R. Jones

Physics

We report the first observation of ionization of Rydberg atoms by subpicosecond, circularly polarized THz radiation. The field amplitude in these pulses is non-negligible for only one-quarter of an optical cycle. The experiment is performed in the short-pulse regime, where the duration of the ionizing pulse is shorter than the classical Kepler period of the Rydberg electron. We find that the ionization probability for these atoms is remarkably insensitive to the time-varying polarization of the THz field.

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Human-Computer Partnership In Decision-Support Systems: Some Design Guidelines, Jens G. Pohl Aug 1997

Human-Computer Partnership In Decision-Support Systems: Some Design Guidelines, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

The design of useful human-computer collaborative decision-support systems requires some understanding of the behavioral and organizational characteristics of human problem solving practices. This paper identifies the principal areas in which computer-based decision making assistance is particularly attractive and critically examines several human problem solving traits that may not be appropriate for direct emulation in the computer-assisted environment. In particular, the author examines the manner in which emotions and hierarchical leadership structures could unnecessarily inhibit the realization of the full potential of a human-computer partnership. Finally, a number of guiding principles are proposed for the design of computer-based decision-support systems.

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A Generalized Mahonian Statistic On Absorption Ring Mappings, Don Rawlings Aug 1997

A Generalized Mahonian Statistic On Absorption Ring Mappings, Don Rawlings

Mathematics

Based on a coin-tossing scheme, a generalized Mahonian statistic is defined on absorption ring mappings and applied in obtaining combinatorial interpretations of the coefficient ofqjin the expansion of ∏ki=1 (1+q+q2+…+qmi). In the permutation case, the statistic coincides with one studied by Han that specializes many known Mahonian statistics.

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Magneto-Aerotaxis In Marine Coccoid Bacteria, Richard B. Frankel, Dennis A. Bazylinski, Mark S. Johnson, Barry L. Taylor Aug 1997

Magneto-Aerotaxis In Marine Coccoid Bacteria, Richard B. Frankel, Dennis A. Bazylinski, Mark S. Johnson, Barry L. Taylor

Physics

Magnetotactic cocci swim persistently along local magnetic field lines in a preferred direction that corresponds to downward migration along geomagnetic field lines. Recently, high cell concentrations of magnetotactic cocci have been found in the water columns of chemically stratified, marine and brackish habitats, and not always in the sediments, as would be expected for persistent, downward-migrating bacteria. Here we report that cells of a pure culture of a marine magnetotactic coccus, designated strain MC-1, formed microaerophilic bands in capillary tubes and used aerotaxis to migrate to a preferred oxygen concentration in an oxygen gradient. Cells were able to swim in …

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Magneto-Optic Trapping Of Β-Decaying 38km, 37k From An On-Line Isotope Separator, J. A. Behr, A. Gorelov, T. Swanson, O. Hausser, K. P. Jackson, M. Trinczek, U. Giesen, J. M. D'Auria, R. Hardy, T. Wilson, P. Choboter, F, Leblond, L. Buchmann, M. Dombsky, C. D.P. Levy, G. Roy, B. A. Brown, J. Dilling Jul 1997

Magneto-Optic Trapping Of Β-Decaying 38km, 37k From An On-Line Isotope Separator, J. A. Behr, A. Gorelov, T. Swanson, O. Hausser, K. P. Jackson, M. Trinczek, U. Giesen, J. M. D'Auria, R. Hardy, T. Wilson, P. Choboter, F, Leblond, L. Buchmann, M. Dombsky, C. D.P. Levy, G. Roy, B. A. Brown, J. Dilling

Mathematics

A magneto-optic trap (MOT) can provide a well-polarized, backing-free, localized source of radioactive atoms for β-decay experiments. We have trapped approximately 6000 atoms of 38Km ( t1/2 = 0.925s) and 2000 atoms of 37K (1.226 s) produced at the TRIUMF on-line separator TISOL in a vapor-cell MOT. We have measured optical isotope shifts and deduced the nuclear charge radii, which show an unusual lack of change at the neutron number N = 20 shell closure. Plans include a search for scalar contributions to the β+- ν correlation in the 0+→0+ decay …

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Hybrid Probabilistic Programs, Alex Dekhtyar, V. S. Subrahmanian Jul 1997

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 [20, 24, 25, 26] 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, …

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Integrating Research Into The Core Curriculum - A Case Study, Erika Rogers Jun 1997

Integrating Research Into The Core Curriculum - A Case Study, Erika Rogers

Computer Science and Software Engineering

No abstract provided.

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Communicating The Role Of Science In Managing Giant Sequoia Groves, Douglas D. Piirto, Robert R. Rogers, Mary C. Bethke May 1997

Communicating The Role Of Science In Managing Giant Sequoia Groves, Douglas D. Piirto, Robert R. Rogers, Mary C. Bethke

Natural Resources Management and Environmental Sciences

Management of giant sequoia groves has been and continues to be a hotly debated issue. The debate has reached Congress, with all parties seeking resolution as to what constitutes an ecologically and publicly acceptable management approach. Determining the correct management approach and communicating that approach to the general public is the crux of the problem. Emerging concepts and principles of forest ecosystem management may provide a mechanism to seek resolution of these management problems related to giant sequoia. The Memorandum of Understanding between the members of the recently formed Giant Sequoia Ecology Cooperative provided the impetus for the development of …

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Review Of Possible Health Effects Of Exposure To Residential Electric And Magnetic Fields, David W. Hafemeister Apr 1997

Review Of Possible Health Effects Of Exposure To Residential Electric And Magnetic Fields, David W. Hafemeister

Physics

No abstract provided.

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A Toolset For The Reengineering Of Complex Computer Systems, Franz J. Kurfess, Mrinalini Lankala, Ashok Vantipalli, Lonnie R. Welch Mar 1997

A Toolset For The Reengineering Of Complex Computer Systems, Franz J. Kurfess, Mrinalini Lankala, Ashok Vantipalli, Lonnie R. Welch

Computer Science and Software Engineering

This paper describes a set of tools for the reengineering of computer-based systems, in particular software. The toolset is based on an abstract intermediate representation (IR) which incorporates the system software architecture at five level of granularity: program level, task level, package/object instance level, subprogram level and statement level. The toolset provides a graphical user interface that allows various views of a software architecture, including call graph, rendezvous graph, call-rendezvous graph, call-data-rendezvous graph, control flow graph and dependence graphs. The information captured by the toolset is useful in software structure, flow and interaction analysis, tasks commonly performed manually during maintenance …

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Electronic Enterprise Engineering - An Outline Of An Architecture, Michael Bieber, Michael Bartolacci, Jerry Fjermestad, Franz J. Kurfess, Qianhong Liu, Marvin Nakayama, Ajaz Rana, Wilhelm Rossak, Richard Scherl, Murat Tanik, Jason Wang, Raymond Yeh, Peter Ng, Richard Sweeney, Fabio Vitali Mar 1997

Electronic Enterprise Engineering - An Outline Of An Architecture, Michael Bieber, Michael Bartolacci, Jerry Fjermestad, Franz J. Kurfess, Qianhong Liu, Marvin Nakayama, Ajaz Rana, Wilhelm Rossak, Richard Scherl, Murat Tanik, Jason Wang, Raymond Yeh, Peter Ng, Richard Sweeney, Fabio Vitali

Computer Science and Software Engineering

In this paper we put forth a vision for organizations to fully embrace computer support. We propose a business-process oriented architecture for Electronic Enterprise Engineering (EEE) that will enable enterprises to manage and evolve all technological and organizational processes effectively; integrate and manage all enterprise information electronically; and empower knowledge workers at all levels with broad decision support capabilities. Our goal is for the EEE architecture to empower an enterprise to make the best use of its informational assets to operate effectively in this new era of electronic commerce. As part of this project we are developing a standard-based, customizable, …

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Brazed Lower Vacuum Housing For A Dewar, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann Feb 1997

Brazed Lower Vacuum Housing For A Dewar, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann

Statistics

A lower vacuum housing (34) of a sensor dewar (26) is fabricated in a single brazing operation from ceramic and metallic components. The components are assembled with ceramic-to-metal interfaces and metal-to-metal interfaces. Brazing is accomplished by active brazing of the ceramic-to-metal interfaces and non-active brazing of the metal-to-metal interfaces. Specific combinations of active braze alloys and non-active braze alloys are provided for various combinations of dewar materials.

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Absorption Processes: Models For Q-Identities, Don Rawlings Feb 1997

Absorption Processes: Models For Q-Identities, Don Rawlings

Mathematics

Several extensions of Blomqvist's absorption process are presented. Inherent in some of the associated distributions is a method for establishingq-identities ranging from properties of Gaussian polynomials to product expansions of basic hypergeometric series to extensions of results on Mahonian statistics. One process links the comajor index to Russian roulette. Also given are examples involving the Rogers–Ramanujan identities that demonstrate howq-expressions may be modeled with absorption processes.

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Feedthrough Pin And Process For Its Preparation, And Electrical Feedthrough Made Therewith, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann Jan 1997

Feedthrough Pin And Process For Its Preparation, And Electrical Feedthrough Made Therewith, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann

Statistics

A feedthrough (34) is formed of a feedthrough plate (44) having at least one bore (46) therethrough and a feedthrough pin (48) hermetically sealed into the bore (46). The feedthrough pin (48) includes an elongated pin (50) having an axis of elongation (52), a recess (54) in at least one end of the pin (50), the recess (54) extending parallel to the axis of elongation (52), and a gold coating (56) within the recess (54). There are preferably a plurality of bores (46) in the feedthrough plate (48) and a corresponding plurality of the feedthrough pins (48). The gold coatings …

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