Transcript of a public hearing held by the Commission on Wartime Contracting in Iraq & Afghanistan held February 2, 2009 in Washington D.C. This hearing includes testimony from witnesses representing the Special Inspector General for Iraqi Reconstruction, the Inspector General of the Department of State and Defense, and U.S. Senators Collins, McCaskill, and Webb on improving wartime contracting. The highlight of the hearing was the release of SIGIR's investigative report on waste, fraud and abuse in the Iraqi reconstruction effort.

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Recent work in classification indicates that significant improvements in accuracy can be obtained by growing an ensemble of classifiers and having them vote for the most popular class. This paper focuses on ensembles of decision trees that are created with a randomized procedure based on sampling. Randomization can be introduced by using random samples of the training data (as in bagging or arcing) and running a conventional tree-building algorithm, or by randomizing the induction algorithm itself. The objective of this paper is to describe our first experiences with a novel randomized tree induction method that uses a subset of samples at a node to determine the split. Our empirical results show that ensembles generated using this approach yield results that are competitive in accuracy and superior in computational cost.

A straightforward numerical analysis of large arrays of arbitrary contour (and possibly missing elements) requires large memory storage and long computation times. Several techniques are currently under development to reduce this cost. One such technique is the GIFFT (Green's function interpolation and FFT) method discussed here that belongs to the class of fast solvers for large structures. This method uses a modification of the standard AIM approach [1] that takes into account the reusability properties of matrices that arise from identical array elements. If the array consists of planar conducting bodies, the array elements are meshed using standard subdomain basis functions, such as the RWG basis. The Green's function is then projected onto a sparse regular grid of separable interpolating polynomials. This grid can then be used in a 2D or 3D FFT to accelerate the matrix-vector product used in an iterative solver [2]. The method has been proven to greatly reduce solve time by speeding up the matrix-vector product computation. The GIFFT approach also reduces fill time and memory requirements, since only the near element interactions need to be calculated exactly. The present work extends GIFFT to layered material Green's functions and multiregion interactions via slots in ground planes. …

The character table of the fully non-rigid water pentamer, (H{sub 2}O){sub 5} is derived for the first time. The group of all feasible permutations is the wreath product group S{sub 5}[S{sub 2}] and it consists of 3840 operations divided into 36 conjugacy classes and irreducible representations. We have shown that the full character table can be constructed using elegant matrix type generator algebra. The character table has been applied to the water pentamer by obtaining the nuclear spin statistical weights of the rovibronic levels and tunneling splittings of the fully non-rigid pentamer. We have also obtained the statistical weights and tunneling splittings of a semi-rigid deuterated pentamer that exhibits pseudo rotation with an averaged C{sub 5h}(G{sub 10}) symmetry used in the assignment of vibration-rotation-tunneling spectra . The correlation tables have been constructed for the semirigid (G{sub 10}) to non-rigid (G{sub 3840}) groups for the rotational levels and tunneling levels. The nuclear spin statistical weights have also been derived for both the limits.

The authors compare a computational model to experimental data for DNA-laden flow in microchannels. The purpose of this work in progress is to validate a new numerical algorithm for viscoelastic flow using the Oldroyd-B model. The numerical approach is a stable and convergent polymeric stress-splitting scheme for viscoelasticity. They treat the hyperbolic part of the equations of motion with an embedded boundary method for solving hyperbolic conservation laws in irregular domains. They enforce incompressibility and evolve velocity and pressure with a projection method. The experiments are performed using epifluorescent microscopy and digital particle image velocimetry to measure velocity fields and track the conformation of biological macromolecules. They present results comparing velocity fields and the observations of computed fluid stress on molecular conformation in various microchannels.

Implementation of a full Kalman filtering scheme in a large OGCM is unrealistic without simplification and one generally reduces the degrees of freedom of the system by prescribing the structure of the prediction error. However, reductions are often made without any objective measure of their appropriateness. In this report, we present results from an ongoing effort to best construct the prediction error capturing the essential ingredients of the system error that includes both a correlated (global) error and a relatively uncorrelated (local) error. The former will be captured by an EOF modes of the model variance whereas the latter can be detected by wavelet analysis.

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Using a combination of statistical mechanics and finite-element interpolation, the authors develop a coarse-grained (CG) alternative to molecular dynamics (MD) for crystalline solids at constant temperature. The new approach is significantly more efficient than MD and generalizes earlier work on the quasi-continuum method. The method is validated by recovering equilibrium properties of single crystal Ni as a function of temperature. CG dynamical simulations of nanoindentation reveal a strong dependence on temperature of the critical stress to nucleate dislocations under the indenter.

The icosahedral symmetry is one of the most intriguing symmetries, as it not only presents challenge but it appears in many fullerenes and high energetic materials such as the dodecahedral N{sub 20}. We have considered the combinatorics of all irreducible representations of the icosahedral symmetry for a number of multinomial partitions for vertex, face and edge colorings in this work. We have constructed the combinatorial tables for all irreducible representations for various multinomial partitions of colorings for the vertices, edge and faces of the icosahedron. These techniques should have important applications to enumerations and spectroscopy of fullerenes and high-energy materials such as N{sub 20}.

As we enter the new millennium there is a growing urgency to address the issue of finding long-range solutions to the world's energy needs. Fusion offers such a solution, provided economically viable means can be found to extract useful energy from fusion reactions. While the magnetic confinement approach to fusion has a long and productive history, to date the mainline approaches to magnetic confinement, namely closed systems such as the tokamak, appear to many as being too large and complex to be acceptable economically, despite the impressive progress that has made toward the achievement of fusion-relevant confinement parameters. Thus there is a growing feeling that it is imperative to search for new and simpler approaches to magnetic fusion, ones that might lead to smaller and more economically attractive fusion power plants.

The Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145 requires an evaluation of the offsite atmospheric dispersion coefficient, {Chi}/Q, as a part of the acceptance criteria in the accident analysis. In it, it requires in sequence computations of (1) the overall site 95th percentile {Chi}/Q, (2) the maximum of the sixteen sector 99.5th percentile {Chi}/Q, and (3) comparison and selection of the worst of the two values for reporting in the safety analysis report (SAR). In all cases, the site-specific meteorology and sector-specific site boundary distances are employed in the evaluation. There are sixteen 22.5-sectors, the nearest site boundary of which is determined within the 45-arc centered on each of the sixteen compass directions.

This document serves as the final report for LDRD project number 04-LW-031, in which we created subpicosecond length, kilo-amp peak current electron beams with the 100 MeV electron/positron linac, using a novel technique designed to produce ultra-short bunch lengths while maintaining the high brightness produced by the S-band photoinjector. In addition, a diagnostic to measure the temporal distribution of the beam was investigated, as conventional pulse length measurement techniques do not apply to extremely short pulses. The creation and diagnosis of beams with both femtosecond length and high transverse brightness is of major concern to next generation acceleration and radiation production experiments. This work leveraged the previous investment in the PLEIADES facility and it's ability to produce high brightness electron beams. In addition, the ultra-short electron pulses generated by this work have been used in conjunction with the PLEIADES X-ray source to produce sub-picosecond, high-brightness X-ray pulses.

Multi-zone models of Type I X-ray bursts are presented that use an adaptive nuclear reaction network of unprecedented size, up to 1300 isotopes, for energy generation and include the most recent measurements and estimates of critical nuclear physics. Convection and radiation transport are included in calculations that carefully follow the changing composition in the accreted layer, both during the bursts themselves and in their ashes. Sequences of bursts, up to 15 in one case, are followed for two choices of accretion rate and metallicity, up to the point where quasi-steady state is achieved. For M = 1.75 x 10{sup -9} M{sub {circle_dot}} yr{sup -1} (and M = 3.5 x 10{sup -10} M{sub {circle_dot}} yr{sup -1}, for low metallicity), combined hydrogen-helium flashes occur. These bursts have light curves with slow rise times (seconds) and long tails. The rise times, shapes, and tails of these light curves are sensitive to the efficiency of nuclear burning at various waiting points along the rp-process path and these sensitivities are explored. Each displays ''compositional inertia'' in that its properties are sensitive to the fact that accretion occurs onto the ashes of previous bursts which contain left-over hydrogen, helium and CNO nuclei.

This paper presents interim results of a feasibility study on carbon dioxide (CO{sub 2}) sequestration in deep saline formations. The focus of the investigation is to examine factors that may affect chemical sequestration of CO{sub 2} in deep saline formations. Findings of the first phase of this investigation were presented in a topical report (Sass et al., 1999a). Preliminary results of the second phase, now underway, have been reported elsewhere (Sass et al., 1999b; 2001). Evaluations of the suitability of Mt. Simon formation for sequestering CO{sub 2} and economic issues are reported by Gupta et al., 1999; 2001; Smith et al., 2001. This study is sponsored by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) under a Novel Concepts project grant. The overall objectives of Phase II experiments were to determine: (1) the potential for long-term sequestration of CO{sub 2} in deep, regional host rock formations; and (2) the effectiveness of overlying caprock as a barrier against upward migration of the injected CO{sub 2}. To meet these goals, experiments were conducted using rock samples from different potential host reservoirs and overlying rocks. In addition, pure mineral samples were used in some experimental runs to investigate specific mineralogical …

There is a keen interest in using periodic structures to model such structures as phased arrays, frequency selective surfaces, and metamaterials. Recent interest has focused on modeling the truncation effects of periodic structures. The GIFFT (Green's function Interpolation using Fast Fourier Transform) method has recently been proposed as an efficient integral equation approach for handling moderate-to-large structures with essentially arbitrary (but identical) elements within each cell. The method uses an array mask--a listing of whether or not an element of the periodic structure is present at each potential cell location within the structure's bounding box--to simplify the handling of arbitrary array boundaries and missing elements. The interaction between adjacent cells is treated using the method of moments in its usual form,but periodicity reduces the number of distinct near-interactions over the entire structure to a 3 x 3 block matrix. (The inverse of this block or even of its central block serves as an effective preconditioner.) The calculation of interactions between non-adjacent cells relies on the following features: (1) For cell sizes less than a few wavelengths, the Green's function is sufficiently smooth that it may be interpolated accurately over both source and observation points within interacting cell pairs via equispaced …

An important task for Homeland Security is the prediction of threat vulnerabilities, such as through the detection of relationships between seemingly disjoint entities. A structure used for this task is a ''semantic graph'', also known as a ''relational data graph'' or an ''attributed relational graph''. These graphs encode relationships as typed links between a pair of typed nodes. Indeed, semantic graphs are very similar to semantic networks used in AI. The node and link types are related through an ontology graph (also known as a schema). Furthermore, each node has a set of attributes associated with it (e.g., ''age'' may be an attribute of a node of type ''person''). Unfortunately, the selection of types and attributes for both nodes and links depends on human expertise and is somewhat subjective and even arbitrary. This subjectiveness introduces biases into any algorithm that operates on semantic graphs. Here, we raise some knowledge representation issues for semantic graphs and provide some possible solutions using recently developed ideas in the field of complex networks. In particular, we use the concept of transitivity to evaluate the relevance of individual links in the semantic graph for detecting relationships. We also propose new statistical measures for semantic graphs …

Z-pinch driven IFE (Z-IFE) requires the design of a repetitive target insertion system that allows coupling of the pulsed power to the target with adequate standoff, and a chamber that can withstand blast and radiation effects from large yield targets. The present strategy for Z-IFE is to use high yield targets ({approx}2-3 GJ/shot), low repetition rate per chamber ({approx}0.1 Hz), and 10 chambers per power plant. In this study, we propose an alternative power plant configuration that uses very high yield targets (20 GJ/shot) in a single chamber operating at 0.1 Hz. A thick-liquid-wall chamber is proposed to absorb the target emission (x-rays, debris and neutrons) and mitigate the blast effects on the chamber wall. The target is attached to the end of a conical shaped Recyclable Transmission Line (RTL) made from a solid coolant (e.g., frozen flibe), or a material that is easily separable from the coolant (e.g., steel). The RTL/target assembly is inserted through a single opening at the top of the chamber for each shot. This study looks at the RTL material choice from a safety and environmental point of view. Materials were assessed according to waste disposal rating (WDR) and contact dose rate (CDR). Neutronics calculations, …

On 4 July 2004 UT, we detected one of Uranus' southern hemispheric features at K' (2.2 {micro}m); this is the first such detection in half a decade of adaptive optics imaging of Uranus at the Keck 10-m telescope. When we observed again on 8 July UT the core had faded, and by 9 July UT it was not seen at K' and barely detectable at H. The detection and subsequent disappearance of the feature indicates rapid dynamical processes in the localized vertical aerosol structure.

A model implementation of the solution of an unsteady nonlinear reaction-diffusion on a SAMR grid using SAMRAI has been developed. This model implementation illustrates the use of new capabilities for implicit timestepping and solution of large-scale systems of nonlinear equations using implementations of inexact Newton methods found in KINSOL and PETSc. This document provides a detailed description of the implementation.

The following arrival information is a supplement to Myers and Schultz (2000). Myers and Schultz (2000) demonstrate the improvement in sparse-network location that can be achieved by using travel-time corrections determined with a Bayesian Kriging algorithm (Schultz et al., 1998). Precise, benchmark locations are provided by a local aftershock study of the 1991 Racha, Georgia earthquake sequence in the Caucasus Mountains (Fuenzalida et al., 1997). A test network is used to relocate the aftershocks with and without travel-time corrections. The test network is meant to represent a typical International Monitoring System configuration, with 6 stations at regional to near teleseismic distances (less then 30{sup o} from the epicenter). The following arrival-time data help to facilitate the reproduction of Myers and Schultz (2000). The arrival picks were obtained from the International Seismic Center (ISC) (openly available) and a Lawrence Livermore National Laboratory (LLNL) analyst (Flori Ryan). Table 1 lists the arrivals in epic time (time since January 1, 1970). The author of the arrival pick is listed as either ''flori'' or ''-'', where ''-'' indicates ISC. Table 2 lists the hypocenter information determined in the local aftershock study of Fuenzalida et al. (1997), and Table 3 lists the station information for …

The 4-8 GHz Transverse Debuncher Cooling Systems are power limited. Misalignments and imperfections in the transverse pickup arrays will generate a longitudinal signal in addition to the betatron signal. This longitudinal signal can use up a significant fraction of the precious TWT power if the imperfections are large enough. This note will summarize calculations of the contributions to the longitudinal signal observed in the transverse systems of the 4-8 GHz Debuncher slow-wave pickup arrays due to various misalignments and imperfections.

This work demonstrates the protective effect of partial titanium substitution in Li{sub x}Ti{sub 0.11}Mn{sub 0.89}O{sub 2} against surface decomposition in room-temperature ionic liquid (RTILs) cells. Raman microscopy and reflectance Fourier transform IR (FTIR) spectroscopy were used to analyze electrodes recovered from cycled Li/Li{sub x}Ti{sub y}Mn{sub 1-y}O{sub 2} (y=0, 0.11) cells containing the 0.5 mol/kg LiTFSI in P{sub 13}FSI RTIL electrolyte. [TFSI=bis(trifluoromethanesulfonyl)imide.] Raman and FTIR spectra of cycled Li{sub x}MnO{sub 2} cathodes showed many distinct bands that can be attributed to both the electrolyte and electrode decomposition products. The thickness of the amorphous porous layer on the Li{sub x}MnO{sub 2} cathode increased during cycling. The surface degradation of Li{sub x}MnO{sub 2} and precipitation of electrolyte decomposition products contributed to the film growth. Improved cycling behavior was observed in cells containing Li{sub x}Ti{sub 0.11}Mn{sub 0.89}O{sub 2}, yet Raman spectroscopy also showed possible surface degradation. The FTIR spectra of cycled Li{sub x}MnO{sub 2} and Li{sub x}Ti{sub 0.11}Mn{sub 0.89}O{sub 2} cathodes displayed bands characteristic for LiSO{sub 3}CF{sub 3} and Li{sub 2}NSO{sub 2}CF{sub 3}, which originate from the reaction of the TFSI anion with traces of water present in the cell.

AP-1 was built to connect the Antiproton Source with the Main Ring accelerator. The beamline was designed to support modes of operation at both 8 GeV and 120 GeV kinetic energy. During the days of Main Ring operation, 120 GeV beam was extracted through the field region of a Lambertson at F-17 and transported approximately 174 meters to the production target. This 'pbar production' mode required a lattice that would focus the proton beam to a small spot size on the target to maximize antiproton yield. The AP-1 line would also be reconfigured to operate at 8 GeV to support antiproton transfers and tuning cycles with protons. The AP-1 line is also connected to the Accumulator via AP-3, so the lattices of these beamlines needed to be compatible. After the Main Injector was built to replace the Main Ring, a beamline was required to connect it with the Antiproton Source. Designers chose to combine beam transfers of 150 GeV protons to the Tevatron, 120 GeV protons to AP-1, 120 GeV protons to Switchyard and 8 GeV proton tune-up or antiproton transfers via AP-1 into the P1 and P2 lines. The P2 line resides in the Main Ring tunnel enclosure between …