Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2000

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 31 - 60 of 2919

Full-Text Articles in Physical Sciences and Mathematics

Classification Of Cwatsets Through Order 23, Ben Goodwin, Dennis Lin Dec 2000

Classification Of Cwatsets Through Order 23, Ben Goodwin, Dennis Lin

Mathematical Sciences Technical Reports (MSTR)

A cwatset of order n can be represented by a transitive subgroup of Sn. Previous work has shown that each conjugacy class of rep­resentation groups corresponds to an isomorphism class of cwatsets. We present a technique for determining whether a particular transitive subgroup of Sn can appear as the representation group for a cwatset of order n. Using this method, we provide a full classification of cwatset isomorphism classes through order 23.

Go to article

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 …

Go to article

Measurement Of The W Boson Mass Using Large Rapidity Electrons, B. Abbott, Gregory R. Snow, D0 Collaboration Dec 2000

Measurement Of The W Boson Mass Using Large Rapidity Electrons, B. Abbott, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We present a measurement of the W boson mass using data collected by the DØ. experiment at the Fermilab Tevatron during 1994–1995. We identify W bosons by their decays to en final states where the electron is detected in a forward calorimeter. We extract the W boson mass MW by fitting the transverse mass and transverse electron and neutrino momentum spectra from a sample of 11 089 W→eν decay candidates. We use a sample of 1687 dielectron events, mostly due toZ→ee decays, to constrain our model of the detector response. Using the forward …

Go to article

Low-Frequency Crossover Of The Fractional Power-Law Conductivity In Srruo3, J. S. Dodge, Christopher P. Weber, J. Corson, J. Orenstein, Z. Schlesinger, J. W. Reiner, M. R. Beasley Dec 2000

Low-Frequency Crossover Of The Fractional Power-Law Conductivity In Srruo3, J. S. Dodge, Christopher P. Weber, J. Corson, J. Orenstein, Z. Schlesinger, J. W. Reiner, M. R. Beasley

Physics

We combine the results of terahertz time-domain spectroscopy with far-infrared transmission and reflectivity to obtain the conductivity of SrRuO 3 over an unprecedented continuous range in frequency, allowing us to characterize the approach to zero frequency as a function of temperature. We show that the conductivity follows a simple phenomenological form, with an analytic structure fundamentally different from that predicted by the standard theory of metals.

Go to article

Sag Testing Of Dairy Farm Milking Equipment, V. J. Gosbell, V. Smith, D. A. Robinson, B. S. Perera Dec 2000

Sag Testing Of Dairy Farm Milking Equipment, V. J. Gosbell, V. Smith, D. A. Robinson, B. S. Perera

Faculty of Informatics - Papers (Archive)

Sags are widely reported as being one of the worst power quality problems and are particularly common in rural areas. Automated milking equipment on dairy farms are thus very susceptible to malfunction by sags. In assessing the relative cost/benefits of sag mitigation in the dairy or the supply network it is important to know the dairy equipment immunity level. It is shown how a harmonic generator can be used to determine this information. Testing revealed that the motor contactor was a critical component as it was unable to ride through a 40% sag longer than about 0.5 seconds. The milking …

Go to article

On Amicable Sequences And Orthogonal Designs, S. Georgiou, C. Koukouvinos, Jennifer Seberry Dec 2000

On Amicable Sequences And Orthogonal Designs, S. Georgiou, C. Koukouvinos, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

In this paper we give a general theorem which can be used to multiply the length of amicable sequences keeping the amicability property and the type of the sequences. As a consequence we have that if there exist two, four or eight amicable sequences of length m and type (al, a2), (al, a2, a3, a4) or (al, a2, ... , a8) then there exist amicable sequences of length ℓ ≡ 0 (mod m) and of the same type. We also present a theorem that produces a set of 2v amicable sequences from a set of v (not necessary amicable) sequences …

Go to article

Stochastic Dynamics Of Systems With Memory (Stochastic Analysis Seminar, University Of Oxford), Salah-Eldin A. Mohammed Dec 2000

Stochastic Dynamics Of Systems With Memory (Stochastic Analysis Seminar, University Of Oxford), Salah-Eldin A. Mohammed

Miscellaneous (presentations, translations, interviews, etc)

No abstract provided.

Go to article

Ga-Doped Zno Films Grown On Gan Templates By Plasma-Assisted Molecular-Beam Epitaxy, H. J. Ko, Yanfang Chen, S. K. Hong, H. Wenisch, T. Yao, David C. Look Dec 2000

Ga-Doped Zno Films Grown On Gan Templates By Plasma-Assisted Molecular-Beam Epitaxy, H. J. Ko, Yanfang Chen, S. K. Hong, H. Wenisch, T. Yao, David C. Look

Physics Faculty Publications

We have investigated the structural and optical properties of Ga-doped ZnO films grown on GaN templates by plasma-assisted molecular-beam epitaxy. The carrier concentration in Ga-doped ZnO films can be controlled from 1.33×1018/cm3 to 1.13×1020/cm3. Despite high Ga incorporation, the linewidth of (0002) ω-rocking curves of Ga-doped ZnO films still lies in the range from 5 to 15 arc min. Photoluminescence (PL) spectra of Ga-doped ZnO films show dominant near-bandedge emission with negligibly weak deep-level emission, independent of carrier concentration. The PL spectrum exhibits a new emission line at 3.358 eV, which corresponds to …

Go to article

The Use Of Benthic Macroinvertebrates By Rainbow Trout (Oncorhynchus Mykiss) In Lake Ogallala, Nebraska, Tyler J. Pearson Dec 2000

The Use Of Benthic Macroinvertebrates By Rainbow Trout (Oncorhynchus Mykiss) In Lake Ogallala, Nebraska, Tyler J. Pearson

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Go to article

Ecological And Physiological Factors Affecting Nesting Success Of Burrowing Owls In Buffalo Gap National Grassland, Randall L. Griebel Dec 2000

Ecological And Physiological Factors Affecting Nesting Success Of Burrowing Owls In Buffalo Gap National Grassland, Randall L. Griebel

School of Natural Resources: Dissertations, Theses, and Student Research

The western burrowing owl (Athene cunicularia hypugea) has been declining throughout much of its range, and in some areas, quite dramatically. In the Great Plains region, these declines appear to be closely associated with declines in prairie dog numbers. Most research to date has taken place on relatively small, fragmented prairie dog colonies. The objectives of this study were to analyze burrowing owl reproductive performance (i.e., clutch size, brood size, and number fledged), and nestling body condition in relation to nest level and colony level factors in Buffalo Gap National Grassland, South Dakota. Buffalo Gap contains large prairie …

Go to article

Water Current, Volume 32, No. 6, December 2000 Dec 2000

Water Current, Volume 32, No. 6, December 2000

Water Current Newsletter

Lake Classification Project Could Establish National Water Quality Ranking Procedure
From the Director: Profiling the Individuals and Efforts That Comprise the Water Center; Faculty Members Named to Administrative Posts
Meet the Faculty: David M. Admiraal; John C. Holz
Quality-Assessed Groundwater Pesticide Data Available Online
Groundwater Guardians
Pesticides Discovered in Ogallala Aquifer According to Recent USGS Study
Spring Semester Water Resources Seminar: Social Sciences Affect on Allocation of Water and Natural Resources
Nominations Solicited for 2001 Nebraska Water Conference
Water News Briefs
Congratulations to Our Winners
Avoid Fall Irrigation
TGF National Award Recipients
Our New Look
Watch Us on the Web …

Go to article

Instrument Performance Enhancement And Modification Through An Extended Instrument Paradigm, Stephen L. Mahan Dec 2000

Instrument Performance Enhancement And Modification Through An Extended Instrument Paradigm, Stephen L. Mahan

Doctoral Dissertations

An extended instrument paradigm is proposed, developed and shown in various applications. The CBM (Chin, Blass, Mahan) method is an extension to the linear systems model of observing systems. In the most obvious and practical application of image enhancement of an instrument characterized by a time-invariant instrumental response function, CBM can be used to enhance images or spectra through a simple convolution application of the CBM filter for a resolution improvement of as much as a factor of two. The CBM method can be used in many applications. We discuss several within this work including imaging through turbulent atmospheres, or …

Go to article

Questing For The Grail: Core Collapse Supernova Simulations With Boltzmann Neutrino Transport, Otis Earl Messer Dec 2000

Questing For The Grail: Core Collapse Supernova Simulations With Boltzmann Neutrino Transport, Otis Earl Messer

Doctoral Dissertations

The importance of exact neutrino transport in spherically symmetric core collapse supernova simulations is explored in this dissertation. The primary tool for these studies is the neutrino radiation hydrodynamics code AGILE-BOLTZTRAN (Mezzacappa & Bruenn 1993a,b,c; Mezzacappa & Messer 1998; Liebendörfer 2000). AGILE-BOLTZTRAN couples the solution of the Boltzmann equation for all three flavors of neutrinos and antineutrinos to a one-dimensional, implicit, adaptive grid hydrodynamics code. Emission, absorption, and scattering of neutrinos from nucleons and nuclei, neutrino-electron scattering, and pair production and annihilation are included as neutrino-matter couplings. Details of the code are described, including the equations solved and their finite …

Go to article

Electronic Excitations In Metals And Semiconductors: Ab Initio Studies Of Realistic Many-Particle Systems, Wei Ku Dec 2000

Electronic Excitations In Metals And Semiconductors: Ab Initio Studies Of Realistic Many-Particle Systems, Wei Ku

Doctoral Dissertations

Electronic excitations in metals and semiconductors, measured through inelastic x-ray scattering, electronic energy-loss spectroscopy, and angle-resolved photoemission, provide valuable information about the intrinsic many-body interactions between electrons in the crystal environment. These dynamical interactions are usually analyzed with intuitive simple models. With the problems studied, which correspond to linear response and quasi-particle excitation, it will be shown that ab initio approaches not only can provide more realistic understanding of microscopic processes and mechanisms, but also result in new theoretical interpretations that resolve a number of remarkable "anomalies." Specifically, these problems include the dispersion of the plasmon lifetime in potassium, the …

Go to article

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 …

Go to article

Osl Dating Supports "High" Sedimentation Rates In Central Arctic Ocean, Martin Jakobsson, Andrew Murray, Jan Backman, Reidar Lovlie Dec 2000

Osl Dating Supports "High" Sedimentation Rates In Central Arctic Ocean, Martin Jakobsson, Andrew Murray, Jan Backman, Reidar Lovlie

Center for Coastal and Ocean Mapping

No abstract provided.

Go to article

New Kinematic Models For Pacific‐North America Motion From 3 Ma To Present, Ii: Evidence For A “Baja California Shear Zone”, Timothy Dixon, Fred Farina, Charles Demets, Francisco Suarez-Vidal, John Fletcher, Bertha Marquez-Azua, M. Meghan Miller, Osvaldo Sanchez, Paul Umhoefer Dec 2000

New Kinematic Models For Pacific‐North America Motion From 3 Ma To Present, Ii: Evidence For A “Baja California Shear Zone”, Timothy Dixon, Fred Farina, Charles Demets, Francisco Suarez-Vidal, John Fletcher, Bertha Marquez-Azua, M. Meghan Miller, Osvaldo Sanchez, Paul Umhoefer

All Faculty Scholarship for the College of the Sciences

We use new models for present‐day Pacific‐North America motion to evaluate the tectonics of offshore regions west of the Californias. Vandenburg in coastal Alta California moves at the Pacific plate velocity within uncertainties (∼1 mm/yr) after correcting for strain accumulation on the San Andreas and San Gregorio‐Hosgri faults with a model that includes a viscoelastic lower crust. Modeled and measured velocities at coastal sites in Baja California south of the Agua Blanca fault, a region that most previous models consider Pacific plate, differ by 3–8 mm/yr, with coastal sites moving slower that the Pacific plate. We interpret these discrepancies in …

Go to article

8 Miles And A Couple Of Antiparticles To Bridgewater State College, Edward Deveney Dec 2000

8 Miles And A Couple Of Antiparticles To Bridgewater State College, Edward Deveney

Bridgewater Review

No abstract provided.

Go to article

Searches For Neutral Higgs Bosons In Quark-Antiquark Tau-Antitau Final States Using The Opal Detector At Lep, James Andrew Hocker '91 Dec 2000

Searches For Neutral Higgs Bosons In Quark-Antiquark Tau-Antitau Final States Using The Opal Detector At Lep, James Andrew Hocker '91

Doctoral Dissertations

Searches for neutral Higgs bosons have been performed with the OPAL detector at LEP. Approximately 170 /pb of e+e- collision data at a center-of-mass energy of 189 GeV have been used to search for the SM process e+e- to HZ as well as for the processes e+e- to hZ and e+e- to hA which occur in extended Higgs theories. The searches are sensitive to final states containing quarks and tau leptons, for which an artificial neural network for the identification of tau leptons was designed. The results have been combined with OPAL searches for other final states to obtain a …

Go to article

Flow Near Submarine Canyons Driven By Constant Winds, Jun She, John M. Klinck Dec 2000

Flow Near Submarine Canyons Driven By Constant Winds, Jun She, John M. Klinck

CCPO Publications

Circulation over coastal submarine canyons driven by constant upwelling or downwelling wind stress is simulated and analyzed with a primitive equation ocean model. Astoria Canyon, on the west coast of North America, is the focus of this study, and model results are consistent with most major features of mean canyon circulation observed in Astoria Canyon. Near-surface flow crosses over the canyon, while a closed cyclone occurs within the canyon. Upwelling prevails within the canyon and is larger than wind-driven upwelling along the adjacent shelf break. Water rises from depths reaching 300 m to the canyon rim and, subsequently, onto the …

Go to article

A Desktop Universe For The Introductory Astronomy Laboratory, Laurence A. Marschall, Glenn A. Snyder, Paul Richard Cooper Dec 2000

A Desktop Universe For The Introductory Astronomy Laboratory, Laurence A. Marschall, Glenn A. Snyder, Paul Richard Cooper

Physics and Astronomy Faculty Publications

What is a well-intentioned astronomy instructor to do? There is no argument that experience with the real world is desirable in any astronomy course, especially the introductory classes that fulfill the science distribution requirements at many colleges and universities. Though it is a simple matter to take students out of doors, show them the motions of the Sun, Moon, and stars, and have them squint for a few seconds at Saturn's rings through a telescope, these activities represent only a small portion of the subject matter of modern astronomy. It is simply not possible, given the constraints of time, weather, …

Go to article

5. Burton Carl Anderson, Otto Vogl Dec 2000

5. Burton Carl Anderson, Otto Vogl

Otto Vogl

No abstract provided.

Go to article

Mean Annual Temperature Trends And Their Vertical Structure In The Tropical Andes, Mathias Yuille, Raymond S. Bradley Dec 2000

Mean Annual Temperature Trends And Their Vertical Structure In The Tropical Andes, Mathias Yuille, Raymond S. Bradley

Raymond S Bradley

Mean annual temperature trends in the tropical Andes were determined over the last six decades ( 1939-1998), to investigate the apparent inconsistency between the observed glacier retreat and the reported slight cooling trend in the lower tropical troposphere after 1979. Our results indicate that temperature in the tropical Andes has increased by 0. 10° - 0. I l °C/decade since 1939. The rate of warming has more than tripled over the last 25 years (0.32° - 0.34 °C/decade) and the last two years of the series, associated with the 1997/98 El Nino, were the warmest of the last six decades. …

Go to article

The Environmental Science Minor: A Disciplinary Approach To Interdisciplinary Studies With A Grounding In Undergraduate Research, Brian E. Bodenbender, Edward C. Hansen, Graham F. Peaslee, Jonathan W. Peterson Dec 2000

The Environmental Science Minor: A Disciplinary Approach To Interdisciplinary Studies With A Grounding In Undergraduate Research, Brian E. Bodenbender, Edward C. Hansen, Graham F. Peaslee, Jonathan W. Peterson

Faculty Publications

No abstract provided.

Go to article

Bayes Optimal Metasearch: A Probabilistic Model For Combining The Results Of Multiple Retrieval Systems, Javed A. Aslam, Mark Montague Dec 2000

Bayes Optimal Metasearch: A Probabilistic Model For Combining The Results Of Multiple Retrieval Systems, Javed A. Aslam, Mark Montague

Computer Science Technical Reports

We introduce a new, probabilistic model for combining the outputs of an arbitrary number of query retrieval systems. By gathering simple statistics on the average performance of a given set of query retrieval systems, we construct a Bayes optimal mechanism for combining the outputs of these systems. Our construction yields a metasearch strategy whose empirical performance nearly always exceeds the performance of any of the constituent systems. Our construction is also robust in the sense that if ``good'' and ``bad'' systems are combined, the performance of the composite is still on par with, or exceeds, that of the best constituent …

Go to article

Reconstructing Ancient Egyptian Tombs, Hany Farid Dec 2000

Reconstructing Ancient Egyptian Tombs, Hany Farid

Computer Science Technical Reports

From the pyramids of Giza to the tombs of Thebes (modern Luxor), ancient Egypt's glorious history has produced remarkable architecture. Sadly, the nearly four million yearly tourists have taken a heavy toll on many of these ancient structures. Of particular concern are many of the tombs located opposite to Luxor on the western bank of the Nile. Digital reconstruction of these tombs has the potential to help document and preserve these important historical structures. Photographing and reconstruction of these tombs poses new and unique problems that this paper begins to address. Techniques for removing image distortions, recovering 3-D shape, and …

Go to article

Commuting Self-Adjoint Extensions Of Symmetric Operators Defined From The Partial Derivatives, Palle Jorgensen, Steen Pedersen Dec 2000

Commuting Self-Adjoint Extensions Of Symmetric Operators Defined From The Partial Derivatives, Palle Jorgensen, Steen Pedersen

Mathematics and Statistics Faculty Publications

We consider the problem of finding commuting self-adjoint extensions of the partial derivatives {(1/i)(∂/∂xj):j=1,...,d} with domain C∞c(Ω) where the self-adjointness is defined relative to L2(Ω), and Ω is a given open subset of Rd.

Go to article

Infrared Spectroscopy Of Symbiotic Stars. Ii. Orbits For Five S-Type Systems With Two-Year Periods, Francis C. Fekel, Kenneth H. Hinkle, Richard Joyce, Michael F. Skrutskie Dec 2000

Infrared Spectroscopy Of Symbiotic Stars. Ii. Orbits For Five S-Type Systems With Two-Year Periods, Francis C. Fekel, Kenneth H. Hinkle, Richard Joyce, Michael F. Skrutskie

Information Systems and Engineering Management Research Publications

Infrared radial velocities have been used to determine orbital elements for the cool giants of five well-known symbiotic systems, Z And, AG Dra, V443 Her, AX Per, and FG Ser, all of which have orbital periods near the two-year mean period for S-type symbiotics. The new orbits are in general agreement with previous orbits derived from optical velocities. From the combined optical and infrared velocities, improved orbital elements for the five systems have been determined. Each of the orbital periods has been determined solely from the radial-velocity data. The orbits are circular and have quite small mass functions of 0.001–0.03 …

Go to article

Chromospherically Active Stars. Xviii. Sorting Out The Variability Of Hd 95559 And Gliese 410=Ds Leonis, Francis C. Fekel, Gregory W. Henry Dec 2000

Chromospherically Active Stars. Xviii. Sorting Out The Variability Of Hd 95559 And Gliese 410=Ds Leonis, Francis C. Fekel, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We have obtained spectroscopy and photometry of HD 95559 and photometry of Gliese 410=DS Leonis. HD 95559 consists of a pair of essentially identical K1 V stars, whose orbital period we refine to 1.52599775+/-0.00000104 days. The system is photometrically variable with a mean period of 1.5264+/-0.0003 days. Despite minimum masses greater than 0.8 Msolar for each component, a search for eclipses proved negative. The lithium abundances of the components of HD 95559 indicate that the system is younger than the Hyades cluster, and its components may even have just arrived on the zero-age main sequence. Gl 410=DS Leo is also …

Go to article

Rogue River Watershed Project / Rogue River Watershed Management Plan, Annis Water Resources Institute Dec 2000

Rogue River Watershed Project / Rogue River Watershed Management Plan, Annis Water Resources Institute

Watershed Management Plans and Reports

The Rogue River is located in west central lower Michigan and is a major tributary of the Grand River. The Rogue River Watershed refers to all the land that is drained by the Rogue River. This area is 167,625 acres and includes portions of Kent, Montcalm, Muskegon, Newaygo, and Ottawa counties. The City of Rockford and Cedar Springs, and the villages of Sparta, Kent City, Sand Lake, and Casnovia are within the Rogue River Watershed boundaries. The Rogue River is fed by wetlands, county drains, lakes, and both warm and cool-cold water tributaries. The cool-cold water tributaries help to sustain …

Go to article

First Prev Next Last