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1995

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Articles 601 - 630 of 2193

Full-Text Articles in Physical Sciences and Mathematics

Gröbner Bases And Syzygy Modules, Yonggan Zhao Aug 1995

Gröbner Bases And Syzygy Modules, Yonggan Zhao

Masters Theses & Specialist Projects

The theory of Gröbner bases has become a useful tool in computational commutative algebra. In this paper, we outline some basic results, as they are found in [1], including the concepts of terms ordering, multivariable polynomial division, Gröbner bases, Buchberger's algorithm, and syzygy modules. Specially, we present several equivalent definitions for Gröbner bases and prove how to compute a Gröbner basis for an ideal I of A = k[x1, x2, • • • , xn] generated by {fl, f2, • • • , f8} through Buchberger's algorithm. As an application of Gröbner bases, we present a standard method (see [1]) …


Uniqueness Of Solutions Of Differential Equations, Gerald Head Aug 1995

Uniqueness Of Solutions Of Differential Equations, Gerald Head

Masters Theses & Specialist Projects

Uniqueness of solutions for ordinary differential equations is studied. The classical theorems which guarantee uniqueness are surveyed, including discussion and examples. Other results concerning uniqueness are considered in the final chapter, including the relationship between convergence of successive approximations and uniqueness, non-uniqueness and continuous dependence on initial conditions.


Multiclass Query Scheduling In Real-Time Database Systems, Hwee Hwa Pang, Michael J. Carey, Miron Livny Aug 1995

Multiclass Query Scheduling In Real-Time Database Systems, Hwee Hwa Pang, Michael J. Carey, Miron Livny

Research Collection School Of Computing and Information Systems

In recent years, a demand for real-time systems that can manipulate large amounts of shared data has led to the emergence of real-time database systems (RTDBS) as a research area. This paper focuses on the problem of scheduling queries in RTDBSs. We introduce and evaluate a new algorithm called Priority Adaptation Query Resource Scheduling (PAQRS) for handling both single class and multiclass query workloads. The performance objective of the algorithm is to minimize the number of missed deadlines, while at the same time ensuring that any deadline misses are scattered across the different classes according to an administratively-defined miss distribution. …


Stratigraphy, Structure, And Environmental Site Assessment Of A Portion Of The Western Blue Ridge, Monroe County, Tennessee, Donald James Geddes Aug 1995

Stratigraphy, Structure, And Environmental Site Assessment Of A Portion Of The Western Blue Ridge, Monroe County, Tennessee, Donald James Geddes

Masters Theses

The western Blue Ridge in southeastern Tennessee is underlain principally by metasedimentary rocks of the Walden Creek and Great Smoky Groups (Ocoee Supergroup). These rocks have traditionally been interpreted as turbiditic synrift sediments deposited along the Late Proterozoic to Early Cambrian southeastern Laurentian margin, which were subsequently metamorphosed and deformed during an early Paleozoic (Taconic) orogeny, then brittlely deformed and thrust westward during a late Paleozoic (Alleghanian) orogeny. More recent hypotheses suggest that at least part of the Walden Creek Group was deposited above the regional Middle Ordovician unconformity in post-Taconic successor basins, and deformed and metamorphosed only during a …


Deep-Well Data Base For Nebraska, Duane R. Mohlam, Raymond R. Burchett Aug 1995

Deep-Well Data Base For Nebraska, Duane R. Mohlam, Raymond R. Burchett

Conservation and Survey Division

No abstract provided.


Study Of The Equilibria Of Parabolic Differential Equations With Interfaces Intersecting The Boundary, Michal Kowalczyk Aug 1995

Study Of The Equilibria Of Parabolic Differential Equations With Interfaces Intersecting The Boundary, Michal Kowalczyk

Doctoral Dissertations

Existence of steady state solutions for the Allen-Cahn and Cahn-Hilliard equations in two dimensional domains is discussed. We are in particular interested in establishing existence of single layered equilibria with the property that their transition layer intersects the boundary. In the case of the Allen-Cahn equation we consider bone-like domains and seek solutions intersecting the flat part of the boundary. We establish conditions for the domain which ensure existence of such equilibria. Their stability is also analyzed. For the Cahn-Hilliard equations we show that there exist equilibria near every point of a local maximum of the curvature of the boundary.


Disk-Directed I/O For An Out-Of-Core Computation, David Kotz Aug 1995

Disk-Directed I/O For An Out-Of-Core Computation, David Kotz

Dartmouth Scholarship

New file systems are critical to obtain good I/O performance on large multiprocessors. Several researchers have suggested the use of \em collective\/ file-system operations, in which all processes in an application cooperate in each I/O request. Others have suggested that the traditional low-level interface (\tt read, write, seek) be augmented with various higher-level requests (e.g., \em read matrix). Collective, high-level requests permit a technique called \em disk-directed I/O\/ to significantly improve performance over traditional file systems and interfaces, at least on simple I/O benchmarks. In this paper, we present the results of experiments with an “out-of-core” LU-decomposition program. Although its …


Determination Of Malmquist Bias And Selection Effects From Monte Carlo Simulations, Wolfram Freudling, Luiz N. Da Costa, Gary Wegner, Riccardo Giovanelli Aug 1995

Determination Of Malmquist Bias And Selection Effects From Monte Carlo Simulations, Wolfram Freudling, Luiz N. Da Costa, Gary Wegner, Riccardo Giovanelli

Dartmouth Scholarship

Maps of the peculiar velocity field derived from distance relations are affected by Malmquist type bias and selection effects. Because of the large number of interdependent effects, they are in most cases difficult to treat analytically. Monte Carlo simulations are used to understand and evaluate these effects. In these simulations the "true" spatial distribution and relevant properties of galaxies as well as selection effects and observational uncertainties are realistically modeled. The results of the simulation can be directly applied to correct observed peculiar velocity maps. The simulation is used to investigate biases in samples of measured peculiar velocities by Lynden-Bell …


College Physics Students' Conceptual Understanding Of Area And Volume, And Relationships Between These Concepts And Students' Understanding Of Physics Concepts, Jiang Yu Aug 1995

College Physics Students' Conceptual Understanding Of Area And Volume, And Relationships Between These Concepts And Students' Understanding Of Physics Concepts, Jiang Yu

Dissertations

Concepts such as area and volume are foundational ideas for many concepts introduced in introductory science courses. At the college level, most instructors typically assume that incoming students have already developed an understanding of these underpinning ideas. However, doubt has surfaced in recent years about students' depth of understanding and mastery of these fundamental concepts. Because deficiencies in understanding basic concepts may relate to the learning of subsequent concepts, instructors have expressed concerns about students' understanding of fundamental ideas and if the failure to understand these ideas hinders students' subsequent progress.

This study was designed to (a) investigate the nature …


Designing A Voice User Interface For A Fuzzy Expert System Tool (Fest), Scott Michael Josephson Aug 1995

Designing A Voice User Interface For A Fuzzy Expert System Tool (Fest), Scott Michael Josephson

Theses and Dissertations

This thesis deals with the design and implementation of a Voice User Interface for the Fuzzy Expert System Tool known as FEST. The interface has voice input and voice output capabilities which allows for a closer communication between the end-user and the computer. The thesis discusses the grammar language, user training, and specific library routines used for the voice input part of the interface. Also the creation and usage of digitized speech is discussed for the voice output part of the interface.


The In Situ Passive Acoustic Measurement Of Shingle Movement Under Waves And Currents: Instrument (Tosca) Development And Preliminary Results, George Voulgaris, Michael Wilkin, Michael Collins Jul 1995

The In Situ Passive Acoustic Measurement Of Shingle Movement Under Waves And Currents: Instrument (Tosca) Development And Preliminary Results, George Voulgaris, Michael Wilkin, Michael Collins

George Voulgaris

An instrumented platform (TOSCA) is described for monitoring coarse-grained sediment transport in high (wave and tidal) energy environments. The system consists of a number of sensors which measure: instantaneous current velocities at three levels; sea surface elevation; and self-generated noise (SGN) caused by intercollision of particles in transit. SGN is related to transport rates, on the basis of laboratory calibration; this, in turn, allows a correlation with simultaneous near-bed shear stress to be established. During the field measurements, PC-based real-time data transmission is realised through the use of a (buoyed) radio telemetry system.

TOSCA has been deployed in eastern Christchurch …


All‐Optical Light Modulation In Bacteriorhodopsin Films, F. J. Aranda, R. Garimella, N. F. Mccarthy, D. Narayana Rao, D.V.G.L.N. Rao, Z. Chen, J. A. Akkar, D. L. Kaplan Jul 1995

All‐Optical Light Modulation In Bacteriorhodopsin Films, F. J. Aranda, R. Garimella, N. F. Mccarthy, D. Narayana Rao, D.V.G.L.N. Rao, Z. Chen, J. A. Akkar, D. L. Kaplan

Physics Faculty Publications

We report a convenient method to obtain all‐optical light modulation in bacteriorhodopsin films using a degenerate four‐wave mixing geometry. Chemically stabilized films of bacteriorhodopsin in a polymer matrix for which the lifetime of the excited M state is tens of seconds were used to demonstrate all‐optical light intensity modulation. The films are observed to be stable over a period of 4 years. Due to the sensitivity of the films, small intensities of order microwatt/ cm2 are required in the modulation experiments. Furthermore the fast photochemical transition from M to B permit reasonably fast modulation speeds independent of the slow …


Numerical Results For The Ground-State Interface In A Random Medium, Alan Middleton Jul 1995

Numerical Results For The Ground-State Interface In A Random Medium, Alan Middleton

Physics - All Scholarship

The problem of determining the ground state of a $d$-dimensional interface embedded in a $(d+1)$-dimensional random medium is treated numerically. Using a minimum-cut algorithm, the exact ground states can be found for a number of problems for which other numerical methods are inexact and slow. In particular, results are presented for the roughness exponents and ground-state energy fluctuations in a random bond Ising model. It is found that the roughness exponent $\zeta = 0.41 \pm 0.01, 0.22 \pm 0.01$, with the related energy exponent being $\theta = 0.84 \pm 0.03, 1.45 \pm 0.04$, in $d = 2, 3$, respectively. These …


Method And Apparatus For Generating Laser Plasma X-Rays, Donald P. Umstadter, Jonathan Workman, Anatoly Maksimchuk, Xinbing Liu Jul 1995

Method And Apparatus For Generating Laser Plasma X-Rays, Donald P. Umstadter, Jonathan Workman, Anatoly Maksimchuk, Xinbing Liu

Donald Umstadter Publications

The present information provides a system and an apparatus to produce x-rays from plasmas by focusing an intense, short duration optical pulse from a laser onto a target. The concentrated energy contained in the focused laser beam ionizes the target material, raising it to a temperature at which ions are produced in a chain reaction ionization, and x-rays are emitted when ions become de-excited (their electrons change energy level) or free electrons recombine with the ions in the plasma. The method comprises controlling pulse time duration of x-rays emitted from a plasma-forming target generating a beam of one or more …


Weak Electron Scattering For The 3he-3h Transition And The Weak Nuclear Form Factors, Michael A. Barnett Jul 1995

Weak Electron Scattering For The 3he-3h Transition And The Weak Nuclear Form Factors, Michael A. Barnett

FIU Electronic Theses and Dissertations

We calculate the differential cross section for weak electron scattering reaction, e + 3He-' 3H + ve, for energies from 100 MeV to 6 GeV as a function of outgoing nucleus angle from 0 to n/2 radians. We find that the differential cross section at low [q2] increases with electron energy from 0.1 GeV to 6.0 GeV, such that the peak value at 6.0 GeV is approximately 3.2 x 10-40 cm 2 / ster, a factor of 10 larger than the peak value at 0.1 GeV. We also find that the width of the peak …


On Detection And Use Of Reflectional Symmetry In Computer Vision., Dipti Prasad Mukherjee Dr. Jul 1995

On Detection And Use Of Reflectional Symmetry In Computer Vision., Dipti Prasad Mukherjee Dr.

Doctoral Theses

The problems of detection and use of reflectional symmetry in the images of planar shape contours are studied. Symmetry, in general, provides important shape representation cues, some of which we utilise here, to acquire viewpoint information and, towards model based shape matching. We concentrate on local reflectional symmetries of emoothly curved planar objecta, though the methoda are equally applicable to polygonal objects; even this could be extended to certain three-dimensional shapes and for other object relations such as rotational symmetry.Under the affine or perspective approximation to image projection, properties of geometrie invariance are used to find (reflectional) symmetric contour pairs. …


37th Rocky Mountain Conference On Analytical Chemistry Jul 1995

37th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 37th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 23-27, 1995.


Light Cone Quantization And Qcd Phenomenology, Stanley J. Brodsky, David G. Robertson Jul 1995

Light Cone Quantization And Qcd Phenomenology, Stanley J. Brodsky, David G. Robertson

Physics Faculty Scholarship

In principle, quantum chromodynamics provides a fundamental description of hadronic and nuclear structure and dynamics in terms of their elementary quark and gluon degrees of freedom. In practice, the direct application of QCD to reactions involving the structure of hadrons is complex because of the interplay of nonperturbative effects such as color confinement and multi-quark coherence. A crucial tool in analyzing such phenomena is the use of relativistic light-cone quantum mechanics and Fock state methods to provide tractable and consistent treatments of relativistic many-body systems. We begin with a brief introduction to light-cone field theory, stressing how it may allow …


Surface Intersection Loop Destruction, Thomas W. Sederberg, Alan K. Zundel Jul 1995

Surface Intersection Loop Destruction, Thomas W. Sederberg, Alan K. Zundel

Faculty Publications

The intersection curve between two surface patches consists of one or more connected components or branches. Each component can be classified as either an open branch, with endpoints on at least one patch boundary, or as a closed loop.


The Hubble Space Telescope Sample Of Radio-Loud Quasars: The LyΑ/HΒ Ratio, Hagai Netzer, M. S. Brotherton, Beverley J. Wills, Mingsheng Han, D. Wills, J. A. Baldwin, Gary J. Ferland, I. W. A. Browne Jul 1995

The Hubble Space Telescope Sample Of Radio-Loud Quasars: The LyΑ/HΒ Ratio, Hagai Netzer, M. S. Brotherton, Beverley J. Wills, Mingsheng Han, D. Wills, J. A. Baldwin, Gary J. Ferland, I. W. A. Browne

Physics and Astronomy Faculty Publications

We have used the first Hubble Space Telescope Faint Object Spectrograph spectra of our sample of radio- loud quasars, and quasi-simultaneous ground-based spectrophotometry, to investigate the intensity ratio Lyα/Hβ, whose small observed values are one of the outstanding problems of active galactic nuclei research. The present sample of 20 quasars with complete flux and profile data shows the first significant correlations of this ratio with other observed properties. The strongest correlations are with various continuum slope indicators: we find smaller Lyα/Hβ ratios in quasars whose continua rise more steeply into the red. The …


Discovery Of Extreme-Ultraviolet Radiation From The Seyfert Galaxy Ton S180 (=Euve J0057−223), Stéphane Vennes, Elisha Polomski, Stuart Bowyer, John R. Thorstensen Jul 1995

Discovery Of Extreme-Ultraviolet Radiation From The Seyfert Galaxy Ton S180 (=Euve J0057−223), Stéphane Vennes, Elisha Polomski, Stuart Bowyer, John R. Thorstensen

Dartmouth Scholarship

We report the detection of intense EUV radiation from the Seyfert 1 galaxy Ton S180. The source EUVE J0057-223, discovered in the Extreme-Ultraviolet Explorer all-sky survey, is only 25'' away from its optical counterpart, well within the position error circle. We present a complete broadband energy distribution of Ton S180 using infrared (IRAS), optical, ultraviolet (IUE) and X-ray (ROSAT) flux measurements, and we find that the measured EUV flux, corrected for neutral hydrogen and helium absorption in the Galaxy, suggests the presence of a strong EUV to soft X-ray flux excess. We briefly discuss …


Animal Waste And The Land-Water Interface, H. Don Scott, Kenneth Steele Jul 1995

Animal Waste And The Land-Water Interface, H. Don Scott, Kenneth Steele

Technical Reports

This book presents abstracts of research studies conducted on animal wastes and the interface between application of animal waste to land. The abstracts were divided into sections which tend to organize summaries of research studies conducted on similar topics. These topics range from characteristics of animal waste to the effects of animal wastes on streams, lakes, wetlands, and watersheds, development of best management practices, nutrient management, edge of field losses and alternative uses. The posters will be available for viewing from 10:00 a.m. Monday, July 17, until 12:00 noon on Wednesday, July 19, 1995.


Origins Of Effective Charge Of Multivalent Ions At A Membrane/Water Interface And Distribution Of 2,3,4,5-Tetrachlorophenol In A Membrane Model System, Piet O. Schmidt Jul 1995

Origins Of Effective Charge Of Multivalent Ions At A Membrane/Water Interface And Distribution Of 2,3,4,5-Tetrachlorophenol In A Membrane Model System, Piet O. Schmidt

Dissertations and Theses

Biological cells and subcellular organelles are surrounded by membranes to form compartments performing specialized functions. Adsorption or partitioning of biologically active compounds into the membrane is the first step in the process of modification of cell function. This work is concerned with the problem of distribution of charged molecules between water and electrically charged membrane surface and between water and octanol. Part I of this thesis is focused on the electrostatic interactions taking place between charges on the membrane and ions present in the aqueous region of the membrane/water interface. The objective was to explore theoretically the origin of anomalous …


The Interaction Between A Thiol Specific Probe (Opa) And The Single Channel Characteristics Of The Reconstituted Ca++ Release Protein From Skeletal Muscle Sarcoplasmic Reticulum, Alexander Braun Jul 1995

The Interaction Between A Thiol Specific Probe (Opa) And The Single Channel Characteristics Of The Reconstituted Ca++ Release Protein From Skeletal Muscle Sarcoplasmic Reticulum, Alexander Braun

Dissertations and Theses

One advantage of higher life-forms over less developed organisms is their ability to respond to signals from their environment with motion. This requires highly specialized contractile cells and a whole locomotion apparatus. In vertebrates, the cells responsible for movement are the skeletal muscle cells. They receive signals from the autonomic nervous system in the form of an action potential, and they contract in an appropriate manner. Calcium is a vital intracellular passenger whose role in muscular function is to initiate contraction. It is released via specific channel proteins from an internal Ca++ store, the sarcoplasmic reticulum, and triggers muscular contraction, …


Reducibility And Thermal Scaling Of Charge Distributions In Multifragmentation, L. Phair, K. Tso, R. Ghetti, G. J. Wozniak, L. G. Moretto, R. T. De Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu Jul 1995

Reducibility And Thermal Scaling Of Charge Distributions In Multifragmentation, L. Phair, K. Tso, R. Ghetti, G. J. Wozniak, L. G. Moretto, R. T. De Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu

Faculty Publications

A strong thermal signature is found in the charge distributions associated with multifragmentation from the reaction 36Ar+197Au at E/A=110 MeV. The n-fold charge distributions are reducible to the onefold charge distributions through a simple scaling that is dictated by fold number and charge conservation.


High-Resolution Ultraviolet Spectroscopy Of Jupiter's Aurora With The Hubble Space Telescope, Y. H. Kim, John J. Caldwell, Jane L. Fox Jul 1995

High-Resolution Ultraviolet Spectroscopy Of Jupiter's Aurora With The Hubble Space Telescope, Y. H. Kim, John J. Caldwell, Jane L. Fox

Jane L. Fox

In 1993 June and July, we obtained 18 spectra of Jupiter's aurora in the wavelength range 1586-1620 Å using the Goddard High Resolution Spectrograph on board the Hubble Space Telescope (HST). The field of view for each observation was 2" × 2". There were 14 spectra of the northern and four spectra of the southern auroral ovals. The spectra are dominated by vibrational-rotational lines of the H2 Lyman band system, from which we have determined H2 rotational temperatures which correspond to the altitude region where most of the auroral emission originates. Intense emission was observed in …


Stability Of Growing Front Of Yba(2)Cu(3)O(X) Superconductor In The Presence Of Pt And Ceo(2) Additions, Gregory Kozlowski, Tom Svobodny Jul 1995

Stability Of Growing Front Of Yba(2)Cu(3)O(X) Superconductor In The Presence Of Pt And Ceo(2) Additions, Gregory Kozlowski, Tom Svobodny

Physics Faculty Publications

Distinctive microstructures of textured YBa2Cu3Ox (123) superconductors were examined by scanning electron microscopy and metallurgical microscopy. The samples were synthesized under a residual thermal gradient by using a modified melt textured growth on a Y2BaCuO5 (211) substrate. Also, the unidirectional solidification by a zone‐melting method was performed to fabricate 123 superconducting bars up to 12 cm long placed on the 211 substrate in the horizontal arrangement, with a growth rate R=0.5 mm/h and a temperature gradient of G=20 °C/cm (G/R=400 °C h/cm2). A ramping …


Poicen.Sas : Censored Poisson Regression, Joseph Hilbe, Gordon Johnston Jul 1995

Poicen.Sas : Censored Poisson Regression, Joseph Hilbe, Gordon Johnston

Joseph M Hilbe

SAS Macro to estimate censored Poisson data, using method of Hilbe. See Hilbe, Joseph M (2011), Negative Binomial Regression, 2nd ed (Cambridge University Press)


Synthesis And Characterization Of Novel Fluorine Containing Alkylsulfonyls And Sulfonates : Fluorinated Sulfonyl Methanes And Derivatives, Nelson R. Holcomb Jul 1995

Synthesis And Characterization Of Novel Fluorine Containing Alkylsulfonyls And Sulfonates : Fluorinated Sulfonyl Methanes And Derivatives, Nelson R. Holcomb

Dissertations and Theses

A series of salts of the strong fluorocarbon acid bis(trifluoromethylsulfonyl)methane were made: (CF3S02 ) 2CHK, (CF3S02 ) 2CHLi, [ (CF3S02 ) 2CH] 2Ca, [ (CF3S02 ) 2CH] 2Hg, (CF3S02 ) 2CHAg, [ (CF3S02 ) 2CH] 3La. Their reactivity and use as organic intermediates were investigated. The salts were made from their corresponding carbonates, oxides, or hydrides. The reaction times for the salts is generally short, however the purification process was laborious, involving recrystallization from organic solvents and drying under vacuum. The lithium salt is being evaluated as a solid state battery electrolyte. Derivatives of bis(trifluoromethylsulfonyl)methane were made by using the …


O-Phthalaldehyde Modification Of Sarcoplasmic Reticulum Calcium Release, Steffen Koehler Jul 1995

O-Phthalaldehyde Modification Of Sarcoplasmic Reticulum Calcium Release, Steffen Koehler

Dissertations and Theses

Muscle contraction is a phenomena which fascinated already the ancient Greeks. People have long sought to understand the mechanism of muscle contraction. Today we know that in order for muscle to contract, an action potential propagates from the nerve cell to the muscle cell. Upon arriving at the muscle cell, via a mechanism called Excitation- Contraction (E-C) coupling, Ca2 + is released from an intracellular membrane system, the sarcoplasmic reticulum (SR), into the intracellular fluid. The increase of intracellular Ca2 + initiates the interaction between the contractile units which results in force development and tension. The least well understood step …