A COMPUTATIONAL WORKBENCH ENVIRONMENT FOR VIRTUAL POWER PLANT SIMULATION (open access)

A COMPUTATIONAL WORKBENCH ENVIRONMENT FOR VIRTUAL POWER PLANT SIMULATION

This is the eighth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT41047. The goal of the project is to develop and demonstrate a computational workbench for simulating the performance of Vision 21 Power Plant Systems. Within the last quarter, good progress has been made on all aspects of the project. Calculations for a full Vision 21 plant configuration have been performed for two coal types and two gasifier types. Good agreement with DOE computed values has been obtained for the Vision 21 configuration under ''baseline'' conditions. Additional model verification has been performed for the flowing slag model that has been implemented into the CFD based gasifier model. Comparisons for the slag, wall and syngas conditions predicted by our model versus values from predictive models that have been published by other researchers show good agreement. The software infrastructure of the Vision 21 workbench has been modified to use a recently released, upgraded version of SCIRun.
Date: January 25, 2003
Creator: Bockelie, Mike; Swensen, Dave; Denison, Martin; Senior, Connie; Chen, Zumao; Linjewile, Temi et al.
Object Type: Report
System: The UNT Digital Library
An evaluation of current high-performance networks (open access)

An evaluation of current high-performance networks

High-end supercomputers are increasingly built out of commodity components, and lack tight integration between the processor and network. This often results in inefficiencies in the communication subsystem, such as high software overheads and/or message latencies. In this paper we use a set of microbenchmarks to quantify the cost of this commoditization, measuring software overhead, latency, and bandwidth on five contemporary supercomputing networks. We compare the performance of the ubiquitous MPI layer to that of lower-level communication layers, and quantify the advantages of the latter for small message performance. We also provide data on the potential for various communication-related optimizations, such as overlapping communication with computation or other communication. Finally, we determine the minimum size needed for a message to be considered 'large' (i.e., bandwidth-bound) on these platforms, and provide historical data on the software overheads of a number of supercomputers over the past decade.
Date: January 25, 2003
Creator: Bell, Christian; Bonachea, Dan; Cote, Yannick; Duell, Jason; Hargrove, Paul; Husbands, Parry et al.
Object Type: Article
System: The UNT Digital Library
Crime Control: The Federal Response (open access)

Crime Control: The Federal Response

Under the federal system in the United States, the states and localities traditionally have held the major responsibility for prevention and control of crime and maintenance of order. For most of the Republic’s history, “police powers” in the broad sense were reserved to the states under the Tenth Amendment to the Constitution. Many still hold that view, but others see a string of court decisions in recent decades as providing the basis for a far more active federal role. Several bills are discussed in this report that address issues related to crime, juvenile justice, and Congress’ evolving role in crime legislation.
Date: January 25, 2003
Creator: O'Bryant, JoAnne
Object Type: Report
System: The UNT Digital Library