Tool Gear: Infrastructure for Building Parallel Programming Tools (open access)

Tool Gear: Infrastructure for Building Parallel Programming Tools

Tool Gear is a software infrastructure for developing performance analysis and other tools. Unlike existing integrated toolkits, which focus on providing a suite of capabilities, Tool Gear is designed to help tool developers create new tools quickly. It combines dynamic instrumentation capabilities with an efficient database and a sophisticated and extensible graphical user interface. This paper describes the design of Tool Gear and presents examples of tools that have been built with it.
Date: December 9, 2002
Creator: May, J M & Gyllenhaal, J
Object Type: Article
System: The UNT Digital Library
Texas Disease Prevention News, Volume 62, Number 25, December 2002 (open access)

Texas Disease Prevention News, Volume 62, Number 25, December 2002

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.
Date: December 9, 2002
Creator: Texas. Department of Health.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Theory and Simulation of the Physics of Space Charge Dominated Beams (open access)

Theory and Simulation of the Physics of Space Charge Dominated Beams

This report describes modeling of intense electron and ion beams in the space charge dominated regime. Space charge collective modes play an important role in the transport of intense beams over long distances. These modes were first observed in particle-in-cell simulations. The work presented here is closely tied to the University of Maryland Electron Ring (UMER) experiment and has application to accelerators for heavy ion beam fusion.
Date: December 9, 2002
Creator: Haber, Irving
Object Type: Report
System: The UNT Digital Library
A New Computational Tool for Simulation of 3-D Flow and Heat Transfer in Boiling Water Reactors (open access)

A New Computational Tool for Simulation of 3-D Flow and Heat Transfer in Boiling Water Reactors

This Phase I work has developed a novel hybrid Lattice Boltzmann Model for the simulation of nonideal fluid thermal dynamics and demonstrated that this model can be used to simulate fundamental two-phase flow processes including boiling initiation, bubble formation and coalescency, and flow-regime formation.
Date: December 9, 2002
Creator: Chen, Hudong
Object Type: Report
System: The UNT Digital Library
Small Business Innovation Research Program (open access)

Small Business Innovation Research Program

None
Date: December 9, 2002
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Federal Tort Reform Legislation: Constitutionality and Summaries of Selected Statutes (open access)

Federal Tort Reform Legislation: Constitutionality and Summaries of Selected Statutes

This report considers the constitutionality of federal tort reform legislation, such as the products liability and medical malpractice reform proposals that have been introduced for the last several Congresses.
Date: December 9, 2002
Creator: Cohen, Henry
Object Type: Report
System: The UNT Digital Library
Permuting sparse rectangular matrices into block-diagonal form (open access)

Permuting sparse rectangular matrices into block-diagonal form

This work investigates the problem of permuting a sparse rectangular matrix into block diagonal form. Block diagonal form of a matrix grants an inherent parallelism for the solution of the deriving problem, as recently investigated in the context of mathematical programming, LU factorization and QR factorization. We propose graph and hypergraph models to represent the nonzero structure of a matrix, which reduce the permutation problem to those of graph partitioning by vertex separator and hypergraph partitioning, respectively. Besides proposing the models to represent sparse matrices and investigating related combinatorial problems, we provide a detailed survey of relevant literature to bridge the gap between different societies, investigate existing techniques for partitioning and propose new ones, and finally present a thorough empirical study of these techniques. Our experiments on a wide range of matrices, using state-of-the-art graph and hypergraph partitioning tools MeTiS and PaT oH, revealed that the proposed methods yield very effective solutions both in terms of solution quality and run time.
Date: December 9, 2002
Creator: Aykanat, Cevdet; Pinar, Ali & Catalyurek, Umit V.
Object Type: Article
System: The UNT Digital Library
AdS orbifolds and Penrose limits (open access)

AdS orbifolds and Penrose limits

In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.
Date: December 9, 2002
Creator: Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M. & Tatar, Radu
Object Type: Article
System: The UNT Digital Library
Fast Optimal Load Balancing Algorithms for 1D Partitioning (open access)

Fast Optimal Load Balancing Algorithms for 1D Partitioning

One-dimensional decomposition of nonuniform workload arrays for optimal load balancing is investigated. The problem has been studied in the literature as ''chains-on-chains partitioning'' problem. Despite extensive research efforts, heuristics are still used in parallel computing community with the ''hope'' of good decompositions and the ''myth'' of exact algorithms being hard to implement and not runtime efficient. The main objective of this paper is to show that using exact algorithms instead of heuristics yields significant load balance improvements with negligible increase in preprocessing time. We provide detailed pseudocodes of our algorithms so that our results can be easily reproduced. We start with a review of literature on chains-on-chains partitioning problem. We propose improvements on these algorithms as well as efficient implementation tips. We also introduce novel algorithms, which are asymptotically and runtime efficient. We experimented with data sets from two different applications: Sparse matrix computations and Direct volume rendering. Experiments showed that the proposed algorithms are 100 times faster than a single sparse-matrix vector multiplication for 64-way decompositions on average. Experiments also verify that load balance can be significantly improved by using exact algorithms instead of heuristics. These two findings show that exact algorithms with efficient implementations discussed in this paper …
Date: December 9, 2002
Creator: Pinar, Ali & Aykanat, Cevdet
Object Type: Article
System: The UNT Digital Library
Jets and dijets in Au+Au and p+p collisions at RHIC (open access)

Jets and dijets in Au+Au and p+p collisions at RHIC

Recent data from RHIC suggest novel nuclear effects in the production of high p{sub T} hadrons. We present results from the STAR detector on high p{sub T} angular correlations in Au+Au and p+p collisions at {radical}S = 200 GeV/c. These two-particle angular correlation measurements verify the presence of a partonic hard scattering and fragmentation component at high p{sub T} in both central and peripheral Au+Au collisions. When triggering on a leading hadron with p{sub T}>4 GeV, we observe a quantitative agreement between the jet cone properties in p+p and all centralities of Au+Au collisions. This quantitative agreement indicates that nearly all hadrons with p{sub T}>4 GeV/c come from jet fragmentation and that jet fragmentation properties are not substantially modified in Au+Au collisions. STAR has also measured the strength of back-to-back high p{sub T} charged hadron correlations, and observes a small suppression of the back-to-back correlation strength in peripheral collisions, and a nearly complete disappearance o f back-to-back correlations in central Au+Au events. These phenomena, together with the observed strong suppression of inclusive yields and large value of elliptic flow at high p{sub T}, are consistent with a model where high p{sub T} hadrons come from partons created near the surface …
Date: December 9, 2002
Creator: Hardtke, D.
Object Type: Article
System: The UNT Digital Library
Assessment of MTI Water Temperature Retrievals with Ground Truth from the Comanche Peak Steam Electric Station Cooling Lake (open access)

Assessment of MTI Water Temperature Retrievals with Ground Truth from the Comanche Peak Steam Electric Station Cooling Lake

Surface water temperatures calculated from Multispectral Thermal Imager (MTI) brightness temperatures and the robust retrieval algorithm, developed by the Los Alamos National Laboratory (LANL), are compared with ground truth measurements at the Squaw Creek reservoir at the Comanche Peak Steam Electric Station near Granbury Texas. Temperatures calculated for thirty-four images covering the period May 2000 to March 2002 are compared with water temperatures measured at 10 instrumented buoy locations supplied by the Savannah River Technology Center. The data set was used to examine the effect of image quality on temperature retrieval as well as to document any bias between the sensor chip arrays (SCA's). A portion of the data set was used to evaluate the influence of proximity to shoreline on the water temperature retrievals. This study found errors in daytime water temperature retrievals of 1.8 C for SCA 2 and 4.0 C for SCA 1. The errors in nighttime water temperature retrievals were 3.8 C for SCA 1. Water temperature retrievals for nighttime appear to be related to image quality with the largest positive bias for the highest quality images and the largest negative bias for the lowest quality images. The daytime data show no apparent relationship between water …
Date: December 9, 2002
Creator: Kurzeja, R.J.
Object Type: Report
System: The UNT Digital Library
Computational Support for Alternative Confinement Concepts Basic Plasma Science (open access)

Computational Support for Alternative Confinement Concepts Basic Plasma Science

This is the final report for contract DE-FG03-99ER54528, ''Computational Support for Alternative Confinement Concepts''. Progress was made in the following areas of investigation: (1) Extensive studies of the confinement properties of conventional Reversed-field Pinch (RFP) configurations (i.e., without current profile control) were performed in collaboration with the Royal Institute of Technology (KTH) in Stockholm, Sweden. These studies were carried out using the full 3-dimensional, finite-{beta}, resistive MHD model in the DEBS code, including ohmic heating and anisotropic heat conduction, and thus for the first time included the self-consistent effects of the dynamo magnetic fluctuations on the confinement properties of the RFP. By using multi-variant regression analysis of these results, scaling laws for various properties characterizing the conventional RFP were obtained. In particular, it was found that the, for constant ratio of I/N (where I is the current and N = na{sup 2} is the line density), and over a range of Lundquist numbers S that approaches 10{sup 6}, the fluctuations scale as {delta}B/B {approx} S{sup -0.14}, the temperature scales as T {approx} I{sup 0.56}, the poloidal beta scales as {beta}{sub {theta}} {approx} I{sup -0.4}, and the energy confinement time scales as {tau}{sub E} {approx} I{sup 0.34}. The degradation of poloidal …
Date: December 9, 2002
Creator: Schnack, Dalton D.
Object Type: Report
System: The UNT Digital Library
Final Report for Crucible Scale Vitrification of Pretreated C-106 Sludge Mixed with Secondary Wastes (open access)

Final Report for Crucible Scale Vitrification of Pretreated C-106 Sludge Mixed with Secondary Wastes

The U.S. Department of Energy (DOE) Office of River Protection (ORP) has acquired Hanford tank waste treatment services at a demonstration scale. The primary objective of the present task was to generate HLW glass samples for subsequent product testing. These tests will help demonstrate the RPP-WTP projects ability to satisfy the product requirements concerning chemical and radionuclide reporting, waste loading, identification and quantification of crystalline and non-crystalline phases.
Date: December 9, 2002
Creator: Crawford, C.
Object Type: Report
System: The UNT Digital Library
Effect of thermo-mechanical stress during quench on Nb3Sn cable performance (open access)

Effect of thermo-mechanical stress during quench on Nb3Sn cable performance

Several high field magnets using Nb{sub 3}Sn superconductor are under development for future particle accelerators. The high levels of stored energy in these magnets can cause high peak temperatures during a quench. The thermomechanical stress generated in the winding during the fast temperature rise can result in a permanent damage of the brittle Nb{sub 3}Sn. Although there are several studies of the critical current degradation of Nb{sub 3}Sn strands due to strain, little is known about how to apply the strain limitations to define a maximum acceptable temperature in the coils during a quench. Therefore, an experimental program was launched, aimed at improving the understanding of the effect of thermo-mechanical stress in coils made from brittle Nb{sub 3}Sn. A first experiment, reported here, was performed on cables. The experimental results were compared to analytical and finite element models. The next step in the experimental program will be to repeat similar measurements in small racetrack coils and later in full size magnets.
Date: December 9, 2002
Creator: al., Linda Imbasciati et
Object Type: Article
System: The UNT Digital Library
An overview of Tevatron Collider Run II at Fermilab (open access)

An overview of Tevatron Collider Run II at Fermilab

The Run II era at Fermilab began in March 2001. Many changes to the accelerator complex were made to support the Tevatron proton-antiproton collider operation with peak luminosities of 2-4 x 10{sup 32} cm{sup -2} s{sup -1} while delivering greater than 5 fb{sup -1} of integrated luminosity before the LHC begins its physics program. This report describes the current status of Run II operations and the machine performances needed to achieve the goals.
Date: December 9, 2002
Creator: Moore, Ronald S
Object Type: Article
System: The UNT Digital Library
Tevatron stripline turn by turn data and the head-tail instability (open access)

Tevatron stripline turn by turn data and the head-tail instability

Vic Scarpine recently collected turn by turn data from the vertical wideband stripline in the Tevatron during proton injection for store 1841. The data file name is ''PHT004.txt''. The single bunch intensity was roughly 200e9. The chromaticity was set to ''+6'' horizontal and ''-2'' vertical to induce instability. The data shown represents an extreme condition that shortly preceded losses leading to an abort. A Yokogawa DL 7200 oscilloscope was used to measure A-B and A+B simultaneously from the 1 meter long stripline. The scope has an analogue bandwidth of 500MHz with a 2 GHz sample rate. On each of the 2048 turns taken, 200 samples were saved. Vic Scarpine assembled some movie files from the same data that revealed intriguing variations in the A-B signals. The Excel data file contains 2048 turns of A+B followed by 2048 turns of A-B. The 200 samples taken on each turn is placed on one line in the file. Beam was injected at line 14 for A+B and line 2062 for A-B. Eight consecutive turns of data are examined starting at 1490 turns after injection (lines 1504-11 for A+B and 3552-9 for A-B).
Date: December 9, 2002
Creator: Crisp, James L
Object Type: Report
System: The UNT Digital Library
Measured longitudinal beam impedance of a Tevatron separator (open access)

Measured longitudinal beam impedance of a Tevatron separator

Twenty two separators are currently installed in the Tevatron. The longitudinal impedance of one of these devices was recently measured with a stretched wire. The stretched wire technique can only measure impedance below the cutoff frequency (500MHz). The geometry of a separator is similar to an un-terminated stripline beam position detector. The separator plates occupy a 13.5'' ID vacuum tank, are 101'' long, 7.8'' wide, and have a 2'' gap between them. The differential characteristic impedance between the plates is estimated to be 81 {Gamma} and the common mode impedance plate to ground is about 42 {Gamma}.
Date: December 9, 2002
Creator: Crisp, James L & Fellenz, Brian J
Object Type: Report
System: The UNT Digital Library
Exploiting Flexibly Assignable Work to Improve Load Balance (open access)

Exploiting Flexibly Assignable Work to Improve Load Balance

In many applications of parallel computing, distribution of the data unambiguously implies distribution of work among processors. But there are exceptions where some tasks can be assigned to one of several processors without altering the total volume of communication. In this paper, we study the problem of exploiting this flexibility in assignment of tasks to improve load balance. We first model the problem in terms of network flow and use combinatorial techniques for its solution. Our parametric search algorithms use maximum flow algorithms for probing on a candidate optimal solution value. We describe two algorithms to solve the assignment problem with log W{sub T} and |P| probe calls, where W{sub T} and |P|, respectively, denote the total workload and number of processors. We also define augmenting paths and cuts for this problem, and show that any algorithm based on augmenting paths can be used to find an optimal solution for the task assignment problem. We then consider a continuous version of the problem, and formulate it as a linearly constrained optimization problem, i.e., min ||Ax||{sub {infinity}}, s.t. Bx = d. To avoid solving an intractable {infinity}-norm optimization problem, we show that in this case minimizing the 2-norm is sufficient to …
Date: December 9, 2002
Creator: Pinar, Ali & Hendrickson, Bruce
Object Type: Article
System: The UNT Digital Library
Beam dynamics issues of muon acceleration in RLA (open access)

Beam dynamics issues of muon acceleration in RLA

A conceptual design of a muon acceleration based on recirculating superconducting linacs is proposed. In the presented scenario, acceleration starts after ionization cooling at 210 MeV/c and proceeds to 20 GeV, where the beam is injected into a neutrino factory storage ring. The key technical issues are addressed; such as: the choice of acceleration technology (superconducting versus normal conducting) and the choice of RF frequency, and finally, implementation of the overall acceleration scheme: capture, acceleration, transport and preservation of large phase space of fast decaying species. Beam transport issues for large-momentum-spread beams are accommodated by appropriate lattice design choices. The proposed arc optics are further optimized with a sextupole correction to suppress chromatic effects contributing to emittance dilution. The presented proof-of-principle design of the arc optics with horizontal separation of multi-pass beams is extended for all passes.
Date: December 9, 2002
Creator: Bogacz, S. A. & Lebedev, V. A.
Object Type: Article
System: The UNT Digital Library
Comparison of MTI Water Temperatures with Ground Truth Measurements at Crater Lake, OR (open access)

Comparison of MTI Water Temperatures with Ground Truth Measurements at Crater Lake, OR

Water surface temperatures calculated with the Los Alamos National Laboratory Robust algorithm were compared with ground truth water temperature measurements near the Oregon State University buoy in Crater Lake, OR. Bulk water measurements at the OSU buoy were corrected for the skin temperature depression and temperature gradient in the top 10 cm of the water to find the water surface temperature for 18 MTI images for June 2000 to Feb 2002. The MTI robust temperatures were found to be biased by 0.1C, with an RMS error of 1.9C compared with the ground truth water surface temperatures. When corrected for the errors in the buoy temperatures the RMS was reduced to 1.3C. This RMS difference is greater than the 1C found at the Pacific Island of Nauru because of the greater variability in the lake temperature and the atmosphere at Crater Lake and the much smaller target area used in the comparison.
Date: December 9, 2002
Creator: Kurzeja, R.J.
Object Type: Report
System: The UNT Digital Library
Two-loop results for MW in the standard model and the MSSM (open access)

Two-loop results for MW in the standard model and the MSSM

Recent higher-order results for the prediction of the W-boson mass, M{sub W}, within the Standard Model are reviewed and an estimate of the remaining theoretical uncertainties of the electroweak precision observables is given. An updated version of a simple numerical parameterization of the result for M{sub W} is presented. Furthermore, leading electroweak two-loop contributions to the precision observables within the MSSM are discussed.
Date: December 9, 2002
Creator: Freitas, Ayres; Heinemeyer, Sven & Weiglein, Georg
Object Type: Article
System: The UNT Digital Library
Diagnostics summary: Working group T9 (open access)

Diagnostics summary: Working group T9

The diagnostics T9 group was charged with reviewing the diagnostic requirements of the proposed accelerators for the future. The list includes the e+e- colliders, Muon Neutrino source, NLC, Proton Driver, Tesla, and the VLHC. While the machines vary widely on diagnostic requirements, there are many similarities that were discovered. The following sections will attempt to point out the similarities and requirements for R and D for these future accelerators. To answer the Charge to the group they organized joint sessions with most of the machine groups and several of the technical groups. In addition, due to their overwhelming importance, they held a special session on position monitor systems. For each of the joint machine group sessions they generated a table of required diagnostic systems, selected the highest priority items using a ranking based on need and RD effort, and pondered a RD path leading from the present state of the technology to a system satisfying the requirement. They used the joint technical group sessions to collect up to date RD plans and to assess the applicability of new ideas in a broad range of topics. As required by their Charge, they have also tried to include promising new ideas.
Date: December 9, 2002
Creator: Pasquinelli, Ralph J. & Ross, Marc C.
Object Type: Article
System: The UNT Digital Library
School Finance: Per-Pupil Spending Differences between Selected Inner City and Suburban Schools Varied by Metropolitan Area (open access)

School Finance: Per-Pupil Spending Differences between Selected Inner City and Suburban Schools Varied by Metropolitan Area

A letter report issued by the General Accounting Office with an abstract that begins "The No Child Left Behind Act of 2001 has focused national attention on the importance of ensuring each child's access to equal educational opportunity. The law seeks to improve the performance of schools and the academic achievement of students, including those who are economically disadvantaged. The Congress, among others, has been concerned about the education of economically disadvantaged students. This study focused on per-pupil spending, factors influencing spending, and other similarities and differences between selected high-poverty inner city schools and selected suburban schools in seven metropolitan areas: Boston, Chicago, Denver, Fort Worth, New York, Oakland, and St. Louis."
Date: December 9, 2002
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Endangered Species: Research Strategy and Long-Term Monitoring Needed for the Mojave Desert Tortoise Recovery Program (open access)

Endangered Species: Research Strategy and Long-Term Monitoring Needed for the Mojave Desert Tortoise Recovery Program

A letter report issued by the General Accounting Office with an abstract that begins "Since the 1980s, biologists have been concerned about declines in the Mojave Desert Tortoise, which ranges through millions of acres in the western United States. The tortoise was first listed as a threatened species under the Endangered Species Act in Utah in 1980; it was later listed as threatened rangewide in 1990. The listing and designation of critical habitat for the tortoise, as well as recommendations in the tortoise recovery plan, have been controversial. In our report, we evaluate--assisted by scientists identified by the National Academy of Sciences--the scientific basis for key decisions related to the tortoise, assess the effectiveness of actions taken to conserve desert tortoises, determine the status of the population, and identify costs and benefits associated with desert tortoise recovery actions."
Date: December 9, 2002
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library