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Cost-effective data-parallel load balancing

Description: Load balancing algorithms improve a program`s performance on unbalanced datasets, but can degrade performance on balanced datasets, because unnecessary load redistributions occur. This paper presents a cost-effective data-parallel load balancing algorithm which performs load redistributions only when the possible savings outweigh the redistribution costs. Experiments with a data-parallel polygon renderer show a performance improvement of up to a factor of 33 on unbalanced datasets and a maximum… more
Date: May 1, 1995
Creator: Hansen, C. D. & Ahrens, J. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

On updating problems in latent semantic indexing

Description: The authors develop new SVD-updating algorithms for three types of updating problems arising from Latent Semantic Indexing (LSI) for information retrieval to deal with rapidly changing text document collections. They also provide theoretical justification for using a reduced-dimension representation of the original document collection in the updating process. Numerical experiments using several standard text document collections show that the new algorithms give higher (interpolated) average pr… more
Date: November 1, 1997
Creator: Simon, H.D. & Zha, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Analysis of the numerical effects of parallelism on a parallel genetic algorithm

Description: This paper examines the effects of relaxed synchronization on both the numerical and parallel efficiency of parallel genetic algorithms (GAs). We describe a coarse-grain geographically structured parallel genetic algorithm. Our experiments show that asynchronous versions of these algorithms have a lower run time than-synchronous GAs. Furthermore, we demonstrate that this improvement in performance is partly due to the fact that the numerical efficiency of the asynchronous genetic algorithm is b… more
Date: September 18, 1995
Creator: Hart, W. E.; Belew, R. K.; Kohn, S. & Baden, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Input/Output operations for hybrid data-flow/control-flow systems

Description: Hybrid data-flow/control-flow system combine the advantages of the data-flow model: functionality and tolerance to communication and memory latencies with the efficient instruction scheduling of the control-flow model. The absence of global state in such hybrid multiprocessors and multiprocessors in general renders the implementation of state tasks such as Input/Output operations very difficult to implement. A distributed file-pointer scheme for incorporations I/O operations onto the data-flow … more
Date: December 31, 1991
Creator: Evripidou, P. & Gaudiot, J. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Calibration and control for range imaging in mobile robot navigation

Description: This paper addresses some issues in the development of sensor-based systems for mobile robot navigation which use range imaging sensors as the primary source for geometric information about the environment. In particular, we describe a model of scanning laser range cameras which takes into account the properties of the mechanical system responsible for image formation and a calibration procedure which yields improved accuracy over previous models. In addition, we describe an algorithm which tak… more
Date: June 1, 1994
Creator: Dorum, O. H.; Hoover, A. & Jones, J. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Research facility access & science education

Description: As Congress voted to terminate the Superconducting Super Collider (SSC) Laboratory in October of 1993, the Department of Energy was encouraged to maximize the benefits to the nation of approximately $2 billion which had already been expended to date on its evolution. Having been recruited to Texas from other intellectually challenging enclaves around the world, many regional scientists, especially physicists, of course, also began to look for viable ways to preserve some of the potentially shor… more
Date: October 1, 1994
Creator: Rosen, S.P. & Teplitz, V.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A distributed computing environment with support for constraint-based task scheduling and scientific experimentation

Description: This paper describes a computing environment which supports computer-based scientific research work. Key features include support for automatic distributed scheduling and execution and computer-based scientific experimentation. A new flexible and extensible scheduling technique that is responsive to a user`s scheduling constraints, such as the ordering of program results and the specification of task assignments and processor utilization levels, is presented. An easy-to-use constraint language … more
Date: April 1, 1997
Creator: Ahrens, J.P.; Shapiro, L.G. & Tanimoto, S.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evaluation of the utility and energy monitoring and control system installed at the US Army, Europe, 409th Base Support Battalion, Military Community at Grafenwoehr, Germany

Description: Under the provisions of Interagency Agreement DOE 1938-B090-A1 between the US Department of Energy (DOE) and the US Army Europe (USAREUR), Martin Marietta Energy Systems, Inc., is providing technical assistance to USAREUR in the areas of computer science, information engineering, energy studies, and engineering and systems development. One of the initial projects authorized under this interagency agreement is the evaluation of utility and energy monitoring and control systems (UEMCSs) installed… more
Date: May 1, 1993
Creator: Broders, M. A. & Ruppel, F. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Distributed input/output processing in data-driven multiprocessors

Description: Data-flow principles of execution provide an elegant way to ensure at runtime that instructions can be executed asynchronously in a parallel environment. However, while the conventional von Neumann model of interpretation has a very rigid ordering of instructions, it is the very asynchronous character of the dataflow model of execution that introduces conflicts when ``state`` tasks (such as I/O operations) must share common data objects. In order to execute I/O operations safely and in parallel… more
Date: December 31, 1992
Creator: Evripidou, P. & Gaudiot, J. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evaluation of the Utility and Energy Monitoring and Control System Installed at the Us Army, Europe, 409th Base Support Battalion, Military Community at Grafenwoehr, Germany

Description: Under the provisions of Interagency Agreement DOE 1938-B090-A1 between the US Department of Energy (DOE) and the US Army Europe (USAREUR), Martin Marietta Energy Systems, Inc., is providing technical assistance to USAREUR in the areas of computer science, information engineering, energy studies, and engineering and systems development. One of the initial projects authorized under this interagency agreement is the evaluation of utility and energy monitoring and control systems (UEMCSs) installed… more
Date: May 1, 1993
Creator: Broders, M. A. & Ruppel, F. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Strengthening programs in science, engineering and mathematics. Third annual progress report

Description: The Division of Natural Sciences and Mathematics at Claflin College consists of the Departments of Biology, Chemistry, Computer Science, Physics, Engineering and Mathematics. It offers a variety of major and minor academic programs designed to meet the mission and objectives of the college. The division`s pursuit to achieve excellence in science education is adversely impacted by the poor academic preparation of entering students and the lack of equipment, facilities and research participation,… more
Date: September 30, 1997
Creator: Sandhu, S. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Immigration: Nonimmigrant H-1B Specialty Worker Issues and Legislation

Description: The 105 Congress is once again considering legislation pertaining to temporary alien workers, striving to balance the needs of U.S. employers with opportunities for U.S. workers. The largest category of these temporary alien workers are the H-1B nonimmigrants — professionals who work in specialty occupations. For the first time, the numerical limits on H-1B visas were reached prior to the end of FY1997, and the FY1998 ceiling was reached in May. Employers in “high tech” industries especially ar… more
Date: August 4, 1998
Creator: Wasem, Ruth Ellen
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

[Computer Science and Telecommunications Board activities]

Description: The board considers technical and policy issues pertaining to computer science, telecommunications, and associated technologies. Functions include providing a base of expertise for these fields in NRC, monitoring and promoting health of these fields, initiating studies of these fields as critical resources and sources of national economic strength, responding to requests for advice, and fostering interaction among the technologies and the other pure and applied science and technology. This docu… more
Date: February 23, 1993
Creator: Blumenthal, M. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

[Computer Science and Telecommunications Board activities]

Description: The board considers technical and policy issues pertaining to computer science, telecommunications, and associated technologies. Functions include providing a base of expertise for these fields in NRC, monitoring and promoting health of these fields, initiating studies of these fields as critical resources and sources of national economic strength, responding to requests for advice, and fostering interaction among the technologies and the other pure and applied science and technology. This docu… more
Date: February 23, 1993
Creator: Blumenthal, M. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Coefficient adaptive triangulation for strongly anisotropic problems

Description: Second order elliptic partial differential equations arise in many important applications, including flow through porous media, heat conduction, the distribution of electrical or magnetic potential. The prototype is the Laplace problem, which in discrete form produces a coefficient matrix that is relatively easy to solve in a regular domain. However, the presence of anisotropy produces a matrix whose condition number is increased, making the resulting linear system more difficult to solve. In t… more
Date: January 1, 1996
Creator: D`Azevedo, E. F.; Romine, C. H. & Donato, J. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Speedup properties of phases in the execution profile of distributed parallel programs

Description: The execution profile of a distributed-memory parallel program specifies the number of busy processors as a function of time. Periods of homogeneous processor utilization are manifested in many execution profiles. These periods can usually be correlated with the algorithms implemented in the underlying parallel code. Three families of methods for smoothing execution profile data are presented. These approaches simplify the problem of detecting end points of periods of homogeneous utilization. T… more
Date: August 1, 1992
Creator: Carlson, B. M.; Wagner, T. D.; Dowdy, L. W. & Worley, P. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Speedup properties of phases in the execution profile of distributed parallel programs

Description: The execution profile of a distributed-memory parallel program specifies the number of busy processors as a function of time. Periods of homogeneous processor utilization are manifested in many execution profiles. These periods can usually be correlated with the algorithms implemented in the underlying parallel code. Three families of methods for smoothing execution profile data are presented. These approaches simplify the problem of detecting end points of periods of homogeneous utilization. T… more
Date: August 1, 1992
Creator: Carlson, B. M.; Wagner, T. D.; Dowdy, L. W. & Worley, P. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Computing connection coefficients of compactly supported wavelets on bounded intervals

Description: Daubechies wavelet basis functions have many properties that make them desirable as a basis for a Galerkin approach to solving PDEs: they are orthogonal, with compact support, and their connection coefficients can be computed. The method developed by Latto et al. to compute connection coefficients does not provide the correct inner product near the endpoints of a bounded interval, making the implementation of boundary conditions problematic. Moreover, the highly oscillatory nature of the wavele… more
Date: April 1, 1997
Creator: Romine, C. H. & Peyton, B. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A new PICL trace file format

Description: A trace file format is described that will be used in future releases of the Portable Instrumented Communication Library (PICL) and ParaGraph. The new format provides improved support for tracing and profiling PICL communication primitives and user-defined events. The new format is also easily extended and may be useful in other instrumentation packages and performance visualization tools.
Date: October 1, 1992
Creator: Worley, P. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A new PICL trace file format

Description: A trace file format is described that will be used in future releases of the Portable Instrumented Communication Library (PICL) and ParaGraph. The new format provides improved support for tracing and profiling PICL communication primitives and user-defined events. The new format is also easily extended and may be useful in other instrumentation packages and performance visualization tools.
Date: October 1, 1992
Creator: Worley, P. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A note on the total least squares problem for coplanar points

Description: The Total Least Squares (TLS) fit to the points (x{sub k}, y{sub k}), k = 1, {hor_ellipsis}, n, minimizes the sum of the squares of the perpendicular distances from the points to the line. This sum is the TLS error, and minimizing its magnitude is appropriate if x{sub k} and y{sub k} are uncertain. A priori formulas for the TLS fit and TLS error to coplanar points were originally derived by Pearson, and they are expressed in terms of the mean, standard deviation and correlation coefficient of t… more
Date: September 1, 1994
Creator: Lee, S. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

EDONIO: Extended distributed object network I/O library

Description: This report describes EDONIO (Extended Distributed Object Network I/O), an enhanced version of DONIO (Distributed Object Network I/O Library) optimized for the Intel Paragon Systems using the new M-ASYNC access mode. DONIO provided fast file I/O capabilities in the Intel iPSC/860 and Paragon distributed memory parallel environments by caching a copy of the entire file in memory distributed across all processors. EDONIO is more memory efficient by caching only a subset of the disk file at a time… more
Date: March 1, 1995
Creator: D`Azevedo, E.F. & Romine, C.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DOLIB: Distributed Object Library

Description: This report describes the use and implementation of DOLIB (Distributed Object Library), a library of routines that emulates global or virtual shared memory on Intel multiprocessor systems. Access to a distributed global array is through explicit calls to gather and scatter. Advantages of using DOLIB include: dynamic allocation and freeing of huge (gigabyte) distributed arrays, both C and FORTRAN callable interfaces, and the ability to mix shared-memory and message-passing programming models for… more
Date: October 1, 1994
Creator: D`Azevedo, E. F. & Romine, C. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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