17 Matching Results

Search Results

Advanced search parameters have been applied.

COPS: Large-scale nonlinearly constrained optimization problems

Description: The authors have started the development of COPS, a collection of large-scale nonlinearly Constrained Optimization Problems. The primary purpose of this collection is to provide difficult test cases for optimization software. Problems in the current version of the collection come from fluid dynamics, population dynamics, optimal design, and optimal control. For each problem they provide a short description of the problem, notes on the formulation of the problem, and results of computational experiments with general optimization solvers. They currently have results for DONLP2, LANCELOT, MINOS, SNOPT, and LOQO.
Date: February 10, 2000
Creator: Bondarenko, A.S.; Bortz, D.M. & More, J.J.
Partner: UNT Libraries Government Documents Department

ISOcxx: The C++ portability package

Description: The level of C++ compliers' adherence to the ISO C++ standard varies considerably from compiler to compiler. This variability has significantly hindered users' attempts as standard-compliant C++ coding practices. ISOcxx is a software package that addresses such deficient aspects of users' C++ development environments. This portability package: (1) probes an environment to identify areas of non-compliance (defects) with the standard, and (2) supplies, where possible, compliance code so as to mitigate (cure) the ill effects of the detected defects. Each defect typically results from a feature that is required by the ISO C++ standard, but that a particular environment omits entirely, provides only incompletely, matches to an outdated draft of the standard, or otherwise incorrectly supports. A cure is applicable if test programs demonstrating the corresponding defect can be successfully compiled and run when the compliance code is incorporated. Where no compliance code is available, client code is nonetheless made aware of the defect and can thus avoid the offending construct. Thus, this package allows client code to be maximally compliant with the international C++ standard, yet still be acceptable to many otherwise-defective environments.
Date: February 9, 2000
Creator: Brown, W.E.
Partner: UNT Libraries Government Documents Department

Implementation of a distributed multiterabyte storage system

Description: The University of Chicago and Argonne National Laboratory are building a highly distributed storage system to meet the needs of a cross-disciplinary group of scientists and to investigate the issues involved in implementing such a system. The storage system is based on IBM 3590/3494 tape technology managed by ADSM software. High-speed wide-area networking is required to support the distributed user community. NFS, DFS, FTP, and other user access methods are supported. A simulation project undertaken to guide system development has provided useful insights even in the calibration and design phases.
Date: November 24, 1999
Creator: Hereld, M.; Nickless, B. & Stevens, R.
Partner: UNT Libraries Government Documents Department

Lattice QCD with commodity hardware and software

Description: Large scale QCD Monte Carlo calculations have typically been performed on either commercial supercomputers or specially built massively parallel computers such as Fermilab's ACPMAPS. Commodity computer systems offer impressive floating point performance-to-cost ratios which exceed those of commercial supercomputers. As high performance networking components approach commodity pricing, it becomes reasonable to assemble a massively parallel supercomputer from commodity parts. The authors describe the work and progress to date of a collaboration working on this problem.
Date: January 25, 2000
Creator: Holmgren, D.J.
Partner: UNT Libraries Government Documents Department

Peak finding using biorthogonal wavelets

Description: The authors show in this paper how they can find the peaks in the input data if the underlying signal is a sum of Lorentzians. In order to project the data into a space of Lorentzian like functions, they show explicitly the construction of scaling functions which look like Lorentzians. From this construction, they can calculate the biorthogonal filter coefficients for both the analysis and synthesis functions. They then compare their biorthogonal wavelets to the FBI (Federal Bureau of Investigations) wavelets when used for peak finding in noisy data. They will show that in this instance, their filters perform much better than the FBI wavelets.
Date: February 1, 2000
Creator: Tan, C.Y.
Partner: UNT Libraries Government Documents Department

Full image spectral analysis of elemental emissions from an echelle spectrograph

Description: A new algorithm compares the background corrected echelle emission image obtained from reference standards to images of unknowns for quantitative elemental analyses. Wavelength was not used in the calculations but instead pixel position and intensity. The data reduction solution was unique to the particular detector/spectrometer. The approach was found useful for several types of images including ICP, DCP and glow discharge images. The analysis scheme required that the emission pattern of standards and background be held in memory. A dual weighting scheme was used that decreased the importance of pixels in high background areas and enhanced the importance of signals from pixels where the standards had emissions. Threshold values were used to limit the calculations to signals in the linear range of the electronics. Logarithmic weighting, (by taking the square root), was found to work well for weighting pixels from the standards. This assured that minor emissions had some influence on the data fit. In the program the best-fit scalar was determined using simple iterative guess, change and test approaches. The test looked for the minimum least square residual value in the areas of the flagged pixels.
Date: January 27, 2000
Creator: Spencer, W.A.
Partner: UNT Libraries Government Documents Department

Dedicated OO expertise applied to Run II software projects

Description: The change in software language and methodology by CDF and D0 to object-oriented from procedural Fortran is significant. Both experiments requested dedicated expertise that could be applied to software design, coding, advice and review. The Fermilab Run II offline computing outside review panel agreed strongly with the request and recommended that the Fermilab Computing Division hire dedicated OO expertise for the CDF/D0/Computing Division joint project effort. This was done and the two experts have been an invaluable addition to the CDF and D0 upgrade software projects and to the Computing Division in general. These experts have encouraged common approaches and increased the overall quality of the upgrade software. Advice on OO techniques and specific advice on C++ coding has been used. Recently a set of software reviews has been accomplished. This has been a very successful instance of a targeted application of computing expertise, and constitutes a very interesting study of how to move toward modern computing methodologies in HEP.
Date: March 7, 2000
Creator: Amidei, D.
Partner: UNT Libraries Government Documents Department

Introduction to Lie operators for accelerator physics

Description: The Lie operators approach is a powerful method to solve complicated problems in different fields of physics. The author and his colleagues applied and improved this approach for calculations of spin motion in beamlines, accelerators, and colliders. The code SpinLie allows one to calculate the level of equilibrium polarization for electron and proton colliders and allows one to investigate the spin resonances during acceleration, colliding, and so on.
Date: January 12, 2000
Creator: Eidelman, Y.
Partner: UNT Libraries Government Documents Department

Plasma simulation studies using multilevel physics models

Description: The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of delta f particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future.
Date: January 19, 2000
Creator: Park, W.; Belova, E.V. & Fu, G.Y.
Partner: UNT Libraries Government Documents Department

Working with arrays of inexpensive EIDE disk drives

Description: In today's marketplace, the cost per Terabyte of disks with EIDE interfaces is about a third that of disks with SCSI. Hence, three times as many particle physics events could be put online with EIDE. The modern EIDE interface includes many of the performance features that appeared earlier in SCSI. EIDE bus speeds approach 33 Megabytes/s and need only be shared between two disks rather than seven disks. The interal I/O rate of very fast (and expensive) SCSI disks is only 50% greater than EIDE disks. Hence, two EIDE disks whose combined cost is much less than one very fast SCSI disk can actually give more data throughput due to the advantage of multiple spindles and head actuators. The authors explore the use of 12 and 16 Gigabyte EIDE disks with motherboard and PCI bus card interfaces on a number of operating systems and CPUs. These include Red Hat Linux and Windows 95/98 on a Pentium, MacOS and Apple's Rhapsody/NeXT/UNIX on a PowerPC, and Sun Solaris on a UltraSparc 10 workstation.
Date: January 25, 2000
Creator: Sanders, D.; Riley, C.; Cremaldi, L.; Summers, D. & Petravick, D.
Partner: UNT Libraries Government Documents Department

Application of stochastic and artificial intelligence methods for nuclear material identification

Description: Nuclear materials safeguard efforts necessitate the use of non-destructive methods to determine the attributes of fissile samples enclosed in special, non-accessible containers. To this end, a large variety of methods has been developed at the Oak Ridge National Laboratory (ORNL) and elsewhere. Usually, a given set of statistics of the stochastic neutron-photon coupled field, such as source-detector, detector-detector cross correlation functions, and multiplicities are measured over a range of known samples to develop calibration algorithms. In this manner, the attributes of unknown samples can be inferred by the use of the calibration results. The organization of this paper is as follows: Section 2 describes the Monte Carlo simulations of source-detector cross correlation functions for a set of uranium metallic samples interrogated by the neutrons and photons from a {sup 252}Cf source. From this database, a set of features is extracted in Section 3. The use of neural networks (NN) and genertic programming to provide sample mass and enrichment values from the input sets of features is illustrated in Sections 4 and 5, respectivelyl. Section 6 is a comparison of the results, while Section 7 is a brief summary of the work.
Date: December 1, 1999
Creator: Pozzi, S. & Segovia, F.J.
Partner: UNT Libraries Government Documents Department

Use of ROOT in the D0 online event monitoring system

Description: The D0 experiment is one of the two High-Energy proton anti-proton collider experiments at Fermilab, USA. Since the detector serves multiple physics purposes, it consists of many different sub-detector systems together with supporting control systems. Therefore, online event monitoring plays a crucial role in ensuring detector performance and data quality by parasitically sampling events during the data taking. ROOT, a physics analysis package developed at CERN, is used in the D0 online monitoring as the main analysis tool, providing a graphical user interface that interacts remotely with an analysis executable and tools to monitor informative histograms as they get updated in shared memory throughout the data taking. In this paper, the authors present the basic structure of the D0 online monitoring system and the use of ROOT in the system.
Date: February 9, 2000
Creator: Snow, J.M.
Partner: UNT Libraries Government Documents Department

Idaho National Engineering and Environmental Laboratory institutional plan -- FY 2000--2004

Description: In this first institutional plan prepared by Bechtel BWXT Idaho, LLC, for the Idaho National Engineering and Environmental Laboratory, the INEEL will focus its efforts on three strategic thrusts: (1) Environmental Management stewardship for DOE-EM, (2) Nuclear reactor technology for DOE-Nuclear Energy (NE), and (3) Energy R and D, demonstration, and deployment (initial focus on biofuels and chemicals from biomass). The first strategic thrust focuses on meeting DOE-EMs environmental cleanup and long-term stewardship needs in a manner that is safe, cost-effective, science-based, and approved by key stakeholders. The science base at the INEEL will be further used to address a grand challenge for the INEEL and the DOE complex--the development of a fundamental scientific understanding of the migration of subsurface contaminants. The second strategic thrust is directed at DOE-NEs needs for safe, economical, waste-minimized, and proliferation-resistant nuclear technologies. As NE lead laboratories, the INEEL and ANL will pursue specific priorities. The third strategic thrust focuses on DOE's needs for clean, efficient, and renewable energy technology. As an initial effort, the INEEL will enhance its capability in biofuels, bioprocessing, and biochemicals. The content of this institutional plan is designed to meet basic DOE requirements for content and structure and reflect the key INEEL strategic thrusts. Updates to this institutional plan will offer additional content and resource refinements.
Date: December 1, 1999
Creator: Enge, R.S.
Partner: UNT Libraries Government Documents Department

SCDAP/RELAP5 lower core plate model

Description: The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. This report describes the justification, theory, implementation, and testing of a new modeling capability which will refine the analysis of the movement of molten material from the core region to the vessel lower head. As molten material moves from the core region through the core support structures it may encounter conditions which will cause it to freeze in the region of the lower core plate, delaying its arrival to the vessel head. The timing of this arrival is significant to reactor safety, because during the time span for material relocation to the lower head, the core may be experiencing steam-limited oxidation. The time at which hot material arrives in a coolant-filled lower vessel head, thereby significantly increasing the steam flow rate through the core region, becomes significant to the progression and timing of a severe accident. This report is a revision of a report INEEL/EXT-00707, entitled ``Preliminary Design Report for SCDAP/RELAP5 Lower Core Plate Model''.
Date: September 1, 1999
Creator: Coryell, E.W. & Griffin, F.P.
Partner: UNT Libraries Government Documents Department

Models for the configuration and integrity of partially oxidized fuel rod cladding at high temperatures -- Final Design Report

Description: Models were designed to resolve deficiencies in the SCDAP/RELAP5/MOD3.2 calculations of the configuration and integrity of hot, partially oxidized cladding. The modeling was improved in five areas. First, the configuration defined for melted metallic cladding retained by an adjacent oxide layer was improved. Second, the empirical model to account for the effect on oxidation of intact cladding is not significantly reduced by the presence of a rather high concentration of relocated material. Third, models for the dissolution of the oxide layer by the metallic layer were implemented into the code. Fourth, a model was added to calculate the thermal stress applied to the oxide layer by the temperature gradient across the oxide layer and to compare this stress to the ultimate strength of the oxide layer. Fifth, a new rule based on theoretical and experimental results was established for identifying the regions of a fuel rod with oxidation of both the inside and outside surfaces of the cladding. The assessment of these models and their integration into SCDAP/RELAP5 showed that the calculated axial distribution in cladding oxidation and relocation are in significantly better agreement with experimental results than is currently the case. The modeling changes account for three aspects of behavior that were not previously calculated correctly. The implementation of these models eliminates to a significant extent the tendency of the SCDAP/RELAP5 code to overpredict the extent of oxidation of the upper part of fuel rods and to underpredict the extent of oxidation of the lower part of fuel rods and the part with a high concentration of relocated material.
Date: January 1, 1999
Creator: Siefken, L.J.
Partner: UNT Libraries Government Documents Department

Core capabilities and technical enhancement, FY-98 annual report

Description: The Core Capability and Technical Enhancement (CCTE) Program, a part of the Verification, Validation, and Engineering Assessment Program, was implemented to enhance and augment the technical capabilities of the Idaho National Engineering and Environmental Laboratory (INEEL). The purpose for strengthening the technical capabilities of the INEEL is to provide the technical base to serve effectively as the Environmental Management Laboratory for the Department of Energy's Office of Environmental Management (EM). An analysis of EM's science and technology needs as well as the technology investments currently being made by EM across the complex was used to formulate a portfolio of research activities designed to address EM's needs without overlapping work being done elsewhere. An additional purpose is to enhance and maintain the technical capabilities and research infrastructure at the INEEL. This is a progress report for fiscal year 1998 for the five CCTE research investment areas: (a) transport aspects of selective mass transport agents, (b) chemistry of environmental surfaces, (c) materials dynamics, (d) characterization science, and (e) computational simulation of mechanical and chemical systems. In addition to the five purely technical research areas, this report deals with the science and technology foundations element of the CCTE from the standpoint of program management and complex-wide issues. This report also provides details of ongoing and future work in all six areas.
Date: April 1, 1999
Creator: Miller, D.L.
Partner: UNT Libraries Government Documents Department

SCDAP/RELAP5 modeling of heat transfer and flow losses in lower head porous debris. Revision 1

Description: Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and nonporous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of nonporous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate ma nner. Designs are described for models to calculate the flow losses and interphase drag of fluid flowing through the interstices of the porous debris, and to apply these variables in the momentum equations in the RELAP5 part of the code. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models ...
Date: May 1, 1999
Creator: Siefken, L.J.; Coryell, E.W.; Paik, S. & Kuo, H.
Partner: UNT Libraries Government Documents Department