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1,637 Matching Results

Start Over Year 1999

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(open access)

JAC: A Journal of Composition Theory, Volume 19, Number 3, 1999

JAC: A Journal of Composition Theory contains a collection of papers regarding writing and rhetoric: "The JAC is a forum for theory, research and pedagogy regarding (1) those writing courses beyond the freshman courses, excluding technical and creative writing, (2) writing in courses which are not themselves writing courses, particularly in the liberal arts and sciences, and (3) work in theory, research or pedagogy which is advanced or progressive and will shed light on the field as a whole while at the same time providing insights for advanced composition" (volume 1, number 1).

Date: 1999

Creator: Association of Teachers of Advanced Composition (U.S.)

Object Type: Journal/Magazine/Newsletter

System: The UNT Digital Library

(open access)

JAC: A Journal of Composition Theory, Volume 19, Number 4, 1999

Date: 1999

Creator: Association of Teachers of Advanced Composition (U.S.)

Object Type: Journal/Magazine/Newsletter

System: The UNT Digital Library

(open access)

Performance Analysis of Distributed Applications using Automatic Classification of Communication Inefficiencies

We present a technique for performance analysis that helps users understand the communication behavior of their message passing applications. Our method automatically classifies individual communication operations and it reveals the cause of communication inefficiencies in the application. This classification allows the developer to focus quickly on the culprits of truly inefficient behavior, rather than manually foraging through massive amounts of performance data. Specifically, we trace the message operations of MPI applications and then classify each individual communication event using decision tree classification, a supervised learning technique. We train our decision tree using microbenchmarks that demonstrate both efficient and inefficient communication. Since our technique adapts to the target system's configuration through these microbenchmarks, we can simultaneously automate the performance analysis process and improve classification accuracy. Our experiments on four applications demonstrate that our technique can improve the accuracy of performance analysis, and dramatically reduce the amount of data that users must encounter.

Date: November 1, 1999

Creator: Vetter, J.

Object Type: Article

System: The UNT Digital Library

(open access)

JAC: A Journal of Composition Theory, Volume 19, Number 1, 1999

Date: 1999

Creator: Association of Teachers of Advanced Composition (U.S.)

Object Type: Journal/Magazine/Newsletter

System: The UNT Digital Library

(open access)

JAC: A Journal of Composition Theory, Volume 19, Number 2, 1999

Date: 1999

Creator: Association of Teachers of Advanced Composition (U.S.)

Object Type: Journal/Magazine/Newsletter

System: The UNT Digital Library

(open access)

The Relationship Between the Grief Process and the Family System: The Role of Affect, Communication, and Cohesion

Sixty-six people who had recently experienced the death of a parent or a spouse completed a questionnaire packet to assess their current grief symptomatology and some characteristics of the relationships within their family. Participants were asked to fill out a questionnaire 4-5 weeks after the death and then again six months later. The present study compared two competing models to explain whether the grief process affects the characteristics of relationships within the family system or that family characteristics affect the experienced grief symptoms.

Date: August 1999

Creator: Schoka, Elaine

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Theory and measurement of the electron cloud effect.

Photoelectrons produced through the interaction of synchrotrons radiation and the vacuum chamber walls can be accelerated by a charged particle beam, acquiring sufficient energy to produce secondary electrons (SES) in collisions with the walls. If the secondary-electron yield (SEY) coefficient of the wall material is greater than one, a run-away condition can develop. In addition to the SEY, the degree of amplification depends on the beam intensity and temporal distribution. As the electron cloud builds up along a train of stored bunches, a transverse perturbation of the head bunch can be communicated to trailing bunches in a wakefield-like interaction with the cloud. The electron cloud effect is especially of concern for the high-intensity PEP-II (SLAC) and KEK B-factories and at the Large Hadron Collider (LHC) at CERN. An initiative was undertaken at the Advanced Photon Source (APS) storage ring to characterize the electron cloud in order to provide realistic limits on critical input parameters in the models and improve their predictive capabilities. An intensive research program was undertaken at CERN to address key issues relating to the LHC. After giving an overview, the recent theoretical and experimental results from the APS and the other laboratories will be discussed.

Date: April 29, 1999

Creator: Harkey, K. C.

Object Type: Article

System: The UNT Digital Library

(open access)

A Theory for the Measurement of Internet Information Retrieval

The purpose of this study was to develop and evaluate a measurement model for Internet information retrieval strategy performance evaluation whose theoretical basis is a modification of the classical measurement model embodied in the Cranfield studies and their progeny. Though not the first, the Cranfield studies were the most influential of the early evaluation experiments. The general problem with this model was and continues to be the subjectivity of the concept of relevance. In cyberspace, information scientists are using quantitative measurement models for evaluating information retrieval performance that are based on the Cranfield model. This research modified this model by incorporating enduser relevance judgment rather than using objective relevance judgments, and by adopting a fundamental unit of measure developed for the cyberspace of Internet information retrieval rather than using recall and precision-type measures. The proposed measure, the Content-bearing Click (CBC) Ratio, was developed as a quantitative measure reflecting the performance of an Internet IR strategy. Since the hypertext "click" is common to many Internet IR strategies, it was chosen as the fundamental unit of measure rather than the "document." The CBC Ratio is a ratio of hypertext click counts that can be viewed as a false drop measure that determines …

Date: May 1999

Creator: MacCall, Steven Leonard

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Prospects for Advanced RF Theory and Modeling

This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed.

Date: April 12, 1999

Creator: Batchelor, D.B.

Object Type: Article

System: The UNT Digital Library

(open access)

Magnetic fields and density functional theory

A major focus of this dissertation is the development of functionals for the magnetic susceptibility and the chemical shielding within the context of magnetic field density functional theory (BDFT). These functionals depend on the electron density in the absence of the field, which is unlike any other treatment of these responses. There have been several advances made within this theory. The first of which is the development of local density functionals for chemical shieldings and magnetic susceptibilities. There are the first such functionals ever proposed. These parameters have been studied by constructing functionals for the current density and then using the Biot-Savart equations to obtain the responses. In order to examine the advantages and disadvantages of the local functionals, they were tested numerically on some small molecules.

Date: February 1, 1999

Creator: Salsbury Jr., Freddie

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Breast Cancer Screening Behaviors of Women of Mexican Descent: A Grounded Theory Approach

A culturally-based theoretical model about how cultural beliefs about cancer and breast cancer screening techniques influence the screening behaviors of women of Mexican descent was developed using grounded theory. Across levels of acculturation and socioeconomic status, 34 women (49 to 81 years old) were interviewed through focus groups. Women who hold more traditional health beliefs about causes, nature, and responsibility with regard to breast cancer are more likely to "feel healthy" and not engage in breast cancer screening. Women who hold more traditional beliefs about propriety of female and health care provider behavior are more likely to "feel indecent" and also not engage in screening. The cultural health belief model is integrated within a sociocultural and a socioeconomic context.

Date: August 1999

Creator: Borrayo, Evelinn A. (Evelinn Arbeth)

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

SEACAS Theory Manuals: Part III. Finite Element Analysis in Nonlinear Solid Mechanics

This report outlines the application of finite element methodology to large deformation solid mechanics problems, detailing also some of the key technological issues that effective finite element formulations must address. The presentation is organized into three major portions: first, a discussion of finite element discretization from the global point of view, emphasizing the relationship between a virtual work principle and the associated fully discrete system, second, a discussion of finite element technology, emphasizing the important theoretical and practical features associated with an individual finite element; and third, detailed description of specific elements that enjoy widespread use, providing some examples of the theoretical ideas already described. Descriptions of problem formulation in nonlinear solid mechanics, nonlinear continuum mechanics, and constitutive modeling are given in three companion reports.

Date: March 1, 1999

Creator: Laursen, T. A.; Attaway, S. W. & Zadoks, R. I.

Object Type: Report

System: The UNT Digital Library

(open access)

Letters to the Editor: The Theory of Essence [#1]

Letter from V. Krishman to the editor questioning a previously published proposal by J. Kenneth Arnette (1995) aimed at solving the problem of mind/body interaction.

Date: Autumn 1999

Creator: Krishnan, V.; Angerpointner, Thomas A. & Horacek, Bruce J.

Object Type: Letter

System: The UNT Digital Library

(open access)

Customer Induced Uncertainty and Its Impact on Organizational Design

How firms facing environmental uncertainty should organize their activities remains an important and challenging question for today's managers and organizational researchers. Proponents of contingency theory have argued that organizations must adjust their activities to fit the level of environmental uncertainty to ensure long-term survival. Although much work has been done on contingency theory, it is clear that our understanding of uncertainty is far from complete. One important aspect of today's organizations is their focus on service, mass customization, and continuous innovation. This focus often results in the customer being brought either into the organization or at least into closer contact with it. Even though the literature provides numerous evidences of the increasing customer focus, it is yet to empirically explain how the complications of customer-organizational interactions might create uncertainty for contemporary organizations. The traditional measure of uncertainty still considers customers as an environmental factor causing demand uncertainty while ignoring the complex nature of customer and organizational encounters. Seeking to further refine the concept of uncertainty and focusing on the contemporary business phenomena, this study develops measures aspects of customer induced uncertainty and examines their relationships with three organizational design variables. Specifically, this study explains the complicated nature of customer - …

Date: August 1999

Creator: Chowdhury, Sanjib Kumar

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

The Theory of Essence. [Part] 3: Neuroanatomical and Neurophysiological Aspects of Interactionism

Article continuing the construction of a dualistic interactionist theory of the near-death experience (NDE), the theory of essence, which was begun in two previous articles. The present work represents an extension of the theory to the microscopic level of analysis, in order to specify in detail the mechanism of essence-brain interaction and to address some general and specific objections to interactionism and the theory of essence.

Date: Winter 1999

Creator: Arnette, J. Kenneth

Object Type: Article

System: The UNT Digital Library

(open access)

Magnetoresistance of One-Dimensional Subbands in Tunnel-Coupled Double Quantum Wires

We study the low-temperature in-plane magnetoresistance of tunnel-coupled quasi-one-dimensional quantum wires. The wires are defined by two pairs of mutually aligned split gates on opposite sides of a < 1 micron thick AlGaAs/GaAs double quantum well heterostructure, allowing independent control of their widths. In the ballistic regime, when both wires are defined and the field is perpendicular to the current, a large resistance peak at ~6 Tesla is observed with a strong gate voltage dependence. The data is consistent with a counting model whereby the number of subbands crossing the Fermi level changes with field due to the formation of an anticrossing in each pair of 1D subbands.

Date: April 27, 1999

Creator: Blount, M. A.; Lyo, S. K.; Moon, J. S.; Reno, J. L.; Simmons, J. A. & Wendt, J. R.

Object Type: Article

System: The UNT Digital Library

transcript

Joint Symposium with Religion, Politics and Science - The Media and Violence - From the Viewpoint of a Federal Prosecutor

Lecture given Wednesday, February 24, 1999, 11:00 AM at Abilene Christian University

Date: February 24, 1999

Creator: McDaniel, Oliver

Object Type: Sound

System: The Portal to Texas History

(open access)

Context-Dependent Prognostics and Health Assessment: A Condition-Based Maintenance Approach That Supports Mission Compliance

In today's manufacturing environment, plants, systems, and equipment are being asked to perform at levels not thought possible a decade ago. The intent is to improve process operations and equipment reliability, availability, and maintainability without costly upgrades. Of course these gains must be achieved without impacting operational performance. Downsizing is also taking its toll on operations. Loss of personnel, particularly those who represent the corporate history, is depleting US industries of their valuable experiential base which has been relied on so heavily in the past. These realizations are causing companies to rethink their condition-based maintenance policies by moving away from reacting to equipment problems to taking a proactive approach by anticipating needs based on market and customer requirements. This paper describes a different approach to condition-based maintenance-context-dependent prognostics and health assessment. This diagnostic capability is developed around a context-dependent model that provides a capability to anticipate impending failures and determine machine performance over a protracted period of time. This prognostic capability links operational requirements to an economic performance model. In this context, a system may provide 100% operability with less than 100% functionality. This paradigm is used to facilitate optimal logistic supply and support.

Date: April 19, 1999

Creator: Allgood, G. O. & Kercel, S. W.

Object Type: Article

System: The UNT Digital Library

(open access)

Spectral ellipsometry of GaSb: Experiment and modelling

The optical constants {epsilon}(E)[{equals}{epsilon}{sub 1}(E) + i{epsilon}{sub 2}(E)] of single crystal GaSb at 300K have been measured using spectral ellipsometry in the range of 0.3--5.3 eV. The {epsilon}(E) spectra displayed distinct structures associated with critical points (CPs) at E{sub 0}(direct gap), spin-orbit split E{sub 0} + {Delta}{sub 0} component, spin-orbit split (E{sub 1}), E{sub 1} + {Delta}{sub 1} and (E{sub 0}{prime}), E{sub 0}{prime} + {Delta}{sub 0}{prime} doublets, as well as E{sub 2}. The experimental data over the entire measured spectral range (after oxide removal) has been fit using the Holden model dielectric function [Phys.Rev.B 56, 4037 (1997)] based on the electronic energy-band structure near these CPs plus excitonic and band-to-band Coulomb enhancement effects at E{sub 0}, E{sub 0} + {Delta}{sub 0}and the E{sub 1}, E{sub 1} + {Delta}{sub 1} doublet. In addition to evaluating the energies of these various band-to-band CPs, information about the binding energy (R{sub 1}) of the two-dimensional exciton related to the E{sub 1}, E{sub 1} + {Delta}{sub 1} CPS was obtained. The value of R{sub 1} was in good agreement with effective mass/{rvec k} {center_dot} {rvec p} theory. The ability to evaluate R{sub 1} has important ramifications for recent first-principles band structure calculations which include exciton …

Date: May 1, 1999

Creator: Charache, G.W.; Mu {tilde n}oz, M.; Wei, K.; Pollak, F.H. & Freeouf, J.L.

Object Type: Report

System: The UNT Digital Library

(open access)

Nucleon form factors '99

The authors review recent progress in the experimental knowledge of and theoretical speculations about nucleon form factors, with special emphasis on the large Q{sup 2} region. There is now a long history of continuous progress in the understanding of electromagnetic form factors at large momentum transfer. After the pioneering works leading to the celebrated quark counting rules, the understanding of hard scattering exclusive processes has been solidly founded. A perturbative QCD subprocess is factorized from a wave function-like distribution amplitude {var_phi}(x{sub i},Q{sup 2}) (x{sub i} being the light cone fractions of momentum carried by valence quarks), the Q{sup 2} dependence of which is analyzed in the renormalization group approach. Although an asymptotic expression emerges from this analysis for the x dependence of the distribution, it was quickly understood that the evolution to the asymptotic Q{sub 2} is very slow and that indeed some non perturbative input is required to get reliable estimates of this distribution amplitude at measurable Q{sup 2}.

Date: June 1, 1999

Creator: Jager, Kees de & Pire, B.

Object Type: Article

System: The UNT Digital Library

(open access)

Domain decomposition methods for a parallel Monte Carlo transport code

Achieving parallelism in simulations that use Monte Carlo transport methods presents interesting challenges. For problems that require domain decomposition, load balance can be harder to achieve. The Monte Carlo transport package may have to operate with other packages that have different optimal domain decompositions for a given problem. To examine some of these issues, we have developed a code that simulates the interaction of a laser with biological tissue; it uses a Monte Carlo method to simulate the laser and a finite element model to simulate the conduction of the temperature field in the tissue. We will present speedup and load balance results obtained for a suite of problems decomposed using a few domain decomposition algorithms we have developed.

Date: January 27, 1999

Creator: Alme, H J; Rodrigue, G H & Zimmerman, G B

Object Type: Article

System: The UNT Digital Library

(open access)

Development of a common data model for scientific simulations

The problem of sharing data among scientific simulation models is a difficult and persistent one. Computational scientists employ an enormous variety of discrete approximations in modeling physical processes on computers. Problems occur when models based on different representations are required to exchange data with one another, or with some other software package. Within the DOE`s Accelerated Strategic Computing Initiative (ASCI), a cross-disciplinary group called the Data Models and Formats (DMF) group, has been working to develop a common data model. The current model is comprised of several layers of increasing semantic complexity. One of these layers is an abstract model based on set theory and topology called the fiber bundle kernel (FBK). This layer provides the flexibility needed to describe a wide range of mesh-approximated functions as well as other entities. This paper briefly describes the ASCI common data model, its mathematical basis, and ASCI prototype development. These prototypes include an object-oriented data management library developed at Los Alamos called the Common Data Model Library or CDMlib, the Vector Bundle API from the Lawrence Livermore Laboratory, and the DMF API from Sandia National Laboratory.

Date: June 1999

Creator: Ambrosiano, J.; Butler, D. M.; Matarazzo, C.; Miller, M. & Schoof, L.

Object Type: Article

System: The UNT Digital Library

transcript

JAC Audio Interview: Chantal Mouffe

JAC interview of Chantal Mouffe discussing political theory in relation to writing, philosophy, and rhetoric.

Date: 1999

Creator: Worsham, Lynn; Olson, Gary A. & Mouffe, Chantal

Object Type: Sound

System: The UNT Digital Library

(open access)

Optical constants of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} lattice-matched to GaSb(001): Experiment and modeling

The optical constants {epsilon}(E)[={epsilon}{sub 1}(E)+i{epsilon}{sub 2}(E)] of two epitaxial layers of GaInAsSb/GaSb have been measured at 300 K using spectral ellipsometry in the range of 0.35--5.3 eV. The {epsilon}(E) spectra displayed distinct structures associated with critical points (CPs) at E{sub 0} (direct gap), spin-orbit split E{sub 0}+{Delta}{sub 0} component, spin-orbit split (E{sub 1}, E{sub 1}+{Delta}{sub 1}) and (E{sub 0}{prime}, E{sub 0}{prime}+{Delta}{sub 0}{prime}) doublets, as well as E{sub 2}. The experimental data over the entire measured spectral range (after oxide removal) has been fit using the Holder model dielectric function [Phys.Rev.B 56, 4037 (1997)] based on the electronic energy-band structure near these CPs plus excitonic and band-to-band Coulomb enhancement effects at E{sub 0.}, E{sub 0}+{Delta}{sub 0} and the E{sub 1}, E{sub 1}+{Delta}{sub 1} doublet. In addition to evaluating the energies of these various band-to-band CPs, information about the binding energy (R{sub 1}) of the two-dimensional exciton related to the E{sub 1}, E{sub 1}+{Delta}{sub 1} CPs was obtained. The value of R{sub 1} was in good agreement with effective mass/k{sup {rightharpoonup}}{center_dot}p{sup {rightharpoonup}} theory. The ability to evaluate R{sub 1} has important ramifications for recent first-principles band structure calculations which include exciton effects at E{sub 0}, E{sub 1}, and E{sub 2} [M.Rohlfing and …

Date: June 1999

Creator: Charache, G. W.; Muñoz, M.; Wei, K.; Pollak, F. H.; Freeouf, J. L. & Wang, C. A.

Object Type: Report

System: The UNT Digital Library

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