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Random Number Generation for Petascale Quantum Monte Carlo (open access)

Random Number Generation for Petascale Quantum Monte Carlo

The quality of random number generators can affect the results of Monte Carlo computations, especially when a large number of random numbers are consumed. Furthermore, correlations present between different random number streams in a parallel computation can further affect the results. The SPRNG software, which the author had developed earlier, has pseudo-random number generators (PRNGs) capable of producing large numbers of streams with large periods. However, they had been empirically tested on only thousand streams earlier. In the work summarized here, we tested the SPRNG generators with over a hundred thousand streams, involving over 10^14 random numbers per test, on some tests. We also tested the popular Mersenne Twister. We believe that these are the largest tests of PRNGs, both in terms of the numbers of streams tested and the number of random numbers tested. We observed defects in some of these generators, including the Mersenne Twister, while a few generators appeared to perform well. We also corrected an error in the implementation of one of the SPRNG generators.
Date: March 16, 2010
Creator: Srinivasan, Ashok
System: The UNT Digital Library
Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons (open access)

Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary …
Date: March 16, 2010
Creator: Baisden, Patricia; Bauge, Eric; Ferguson, James; Gilliam, David; Granier, Thierry; Jeanloz, Raymond et al.
System: The UNT Digital Library
High Energy Density Physics Experiments With Intense Heavy Ion Beams (open access)

High Energy Density Physics Experiments With Intense Heavy Ion Beams

The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in …
Date: March 16, 2010
Creator: Henestroza, E.; Leitner, M.; Logan, B. G.; More, R. M.; Roy, P. K.; Ni, P. et al.
System: The UNT Digital Library
The Congressional Research Service and the American Legislative Process (open access)

The Congressional Research Service and the American Legislative Process

This report details the ways in which the Library of Congress supports and serves the members of Congress
Date: March 16, 2010
Creator: Brudnick, Ida A. & Back, Stanley
System: The UNT Digital Library
Federal Stafford Act Disaster Assistance: Presidential Declarations, Eligible Activities, and Funding (open access)

Federal Stafford Act Disaster Assistance: Presidential Declarations, Eligible Activities, and Funding

This report provides an overview of the Stafford Act and Stafford Act declarations. The report discusses the types of assistance and eligibility, funding caps and cost shares, hazard mitigation assistance, disaster relief funds, and other issues for the 111th Congress.
Date: March 16, 2010
Creator: Bea, Keith
System: The UNT Digital Library
The Haitian Economy and the HOPE Act (open access)

The Haitian Economy and the HOPE Act

This report discusses the HOPE Act as it relates to U.S. trade policy, the Haitian economy, and post-earthquake reconstruction efforts.
Date: March 16, 2010
Creator: Hornbeck, J. F.
System: The UNT Digital Library
German Foreign and Security Policy: Trends and Transatlantic Implications (open access)

German Foreign and Security Policy: Trends and Transatlantic Implications

This report provides an introduction to German foreign and security policy. The report discusses the foundations of German foreign policy, Germany in the European Union (EU), evolving security and defense policy, and transatalantic implications.
Date: March 16, 2010
Creator: Belkin, Paul
System: The UNT Digital Library
Terrorism and Security Issues Facing the Water Infrastructure Sector (open access)

Terrorism and Security Issues Facing the Water Infrastructure Sector

This report presents an overview of the large and diverse sector of water infrastructure systems, describes security-related actions by the government and private sector since September 11, 2001, and discusses additional policy issues and responses, including congressional interest.
Date: March 16, 2010
Creator: Copeland, Claudia
System: The UNT Digital Library
Interim Continuing Resolutions (CRs): Potential Impacts on Agency Operations (open access)

Interim Continuing Resolutions (CRs): Potential Impacts on Agency Operations

This report discusses how an interim continuing resolutions (CRs), provisions and requirements may impact directly upon an agency. Second, the report analyzes Office of Management and Budget (OMB) and agency documents that have provided guidance or requirements for how an agency should navigate through periods of interim CRs. Third, the report analyzes brief mentions of claims of impact contained in Government Accountability Office (GAO) reports from a 20-year span.
Date: March 16, 2010
Creator: Brass, Clinton T.
System: The UNT Digital Library
Urban Search and Rescue Task Forces: Facts and Issues (open access)

Urban Search and Rescue Task Forces: Facts and Issues

This report discusses Urban Search and Rescue (USAR) Task Forces, which have been certified, trained, and funded by the federal government. The task forces represent a partnership involving federal, local government, and private sector experts. Most recently, USAR teams received considerable publicity, and reportedly achieved life-saving results, in their mission to Haiti after the earthquakes of early 2010.
Date: March 16, 2010
Creator: Bea, Keith
System: The UNT Digital Library
Emergency Communications: The Future of 911 (open access)

Emergency Communications: The Future of 911

This report discusses possible paths toward the modernization of the 911 infrastructure. Efforts to splice newer, digital technologies onto the aging infrastructure have created points of failure where a call can be dropped or misdirected, sometimes with tragic consequences.
Date: March 16, 2010
Creator: Moore, Linda K.
System: The UNT Digital Library
Libya: Background and U.S. Relations (open access)

Libya: Background and U.S. Relations

This report discusses the recent revolution in Libya, from its 2011 uprising to the end of the Qadhafi era. It specifically looks at Libya's weapons of mass destruction (WMD) disarmament, political reform and human rights, and energy as it relates to the Libyan economy.
Date: March 16, 2010
Creator: Blanchard, Christopher M.
System: The UNT Digital Library
The International Criminal Court (ICC): Jurisdiction, Extradition, and U.S. Policy (open access)

The International Criminal Court (ICC): Jurisdiction, Extradition, and U.S. Policy

This report focuses on the process by which the Office of the Prosecutor investigates allegations of war crimes and second on U.S policy towards the International Criminal Court (ICC) and how the court might assert jurisdiction over U.S. nationals.
Date: March 16, 2010
Creator: Barbour, Emily C. & Weed, Matthew C.
System: The UNT Digital Library
Immigration: Policy Considerations Related to Guest Worker Programs (open access)

Immigration: Policy Considerations Related to Guest Worker Programs

This report discusses guest worker programs. The United States has two main programs for temporarily importing low-skilled workers, or guest workers. Agricultural guest workers enter through the H-2A visa program, and other guest workers enter through the H-2B visa program.
Date: March 16, 2010
Creator: Bruno, Andorra
System: The UNT Digital Library
Political Status of Puerto Rico: Options for Congress (open access)

Political Status of Puerto Rico: Options for Congress

This report discusses the current U.S.-Puerto Rico relationship, the history of said relationship, and the current political state of Puerto Rico, as well as relevant pieces of U.S. Congressional legislation concerning Puerto Rico.
Date: March 16, 2010
Creator: Bea, Keith & Garrett, R. Sam
System: The UNT Digital Library
U.S. Insular Areas: Opportunities Exist to Improve Interior's Grant Oversight and Reduce the Potential for Mismanagement (open access)

U.S. Insular Areas: Opportunities Exist to Improve Interior's Grant Oversight and Reduce the Potential for Mismanagement

A letter report issued by the Government Accountability Office with an abstract that begins "The U.S. insular areas of American Samoa, the Commonwealth of the Northern Mariana Islands (CNMI), Guam, and the U.S. Virgin Islands (USVI) face serious economic and fiscal challenges and rely on federal funding to deliver critical services. The Department of the Interior (Interior), through its Office of Insular Affairs (OIA), provides roughly $70 million in grant funds annually to increase insular area self-sufficiency. GAO and others have raised concerns regarding insular areas' internal control weaknesses, which increase the risk of grant fund mismanagement. GAO was asked to determine (1) whether previously reported internal control weaknesses have been addressed and, if not, to what extent they are prevalent among OIA grant projects; (2) the challenges, if any, insular areas face in implementing OIA grant projects; and (3) the extent to which OIA has taken action to improve grant project implementation and management. GAO reviewed a random sample of 173 OIA grant files, conducted site visits, and interviewed OIA and insular area officials."
Date: March 16, 2010
Creator: United States. Government Accountability Office.
System: The UNT Digital Library