Transcript of Commission on Wartime Contracting in Iraq & Afghanistan Hearing: July 26, 2010 (open access)

Transcript of Commission on Wartime Contracting in Iraq & Afghanistan Hearing: July 26, 2010

Transcript of a public hearing held by the Commission on Wartime Contracting in Iraq & Afghanistan held July 26,2010 in Washington, D.C. This hearing includes testimony from three panels of witnesses representing government agencies, contractors and subcontractors on transparency and accountability challenges associated with subcontracting.
Date: July 26, 2010
Creator: CQ Transcriptions
Object Type: Text
System: The UNT Digital Library
Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy (open access)

Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy

We present scanning SQUID microscopy data on the superconductors Sr{sub 2}RuO{sub 4} (T{sub c} = 1.5 K) and PrOs{sub 4}Sb{sub 12} (T{sub c} = 1.8 K). In both of these materials, superconductivity-related time-reversal symmetry-breaking fields have been observed by muon spin rotation; our aim was to visualize the structure of these fields. However in neither Sr{sub 2}RuO{sub 4} nor PrOs{sub 4}Sb{sub 12} do we observe spontaneous superconductivity-related magnetization. In Sr{sub 2}RuO{sub 4}, many experimental results have been interpreted on the basis of a p{sub x} {+-} ip{sub y} superconducting order parameter. This order parameter is expected to give spontaneous magnetic induction at sample edges and order parameter domain walls. Supposing large domains, our data restrict domain wall and edge fields to no more than {approx}0.1% and {approx}0.2% of the expected magnitude, respectively. Alternatively, if the magnetization is of the expected order, the typical domain size is limited to {approx}30 nm for random domains, or {approx} 500 nm for periodic domains.
Date: August 26, 2010
Creator: Moler, Kathryn
Object Type: Article
System: The UNT Digital Library
No Prejudice in Space (open access)

No Prejudice in Space

We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, in …
Date: August 26, 2010
Creator: Cotta, R. C.; Gainer, J. S.; Hewett, J. L. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
A Single-Shot Method for Measuring Femtosecond Bunch Length in Linac-Based Free-Electron Lasers (open access)

A Single-Shot Method for Measuring Femtosecond Bunch Length in Linac-Based Free-Electron Lasers

There is growing interest in the generation and characterization of femtosecond and subfemtosecond pulses from linac-based free-electron lasers (FELs). In this report, following the method of Ricci and Smith [Phys. Rev. ST Accel. Beams 3, 032801 (2000)], we investigate the measurement of the longitudinal bunch profile of an ultrashort electron bunch produced by these FELs. We show that this method can be applied in a straightforward manner at x-ray FEL facilities such as the Linac Coherent Light Source by slightly adjusting the second bunch compressor followed by running the bunch on an rf zero-crossing phase of the final linac. We find that the linac wakefield strongly perturbs the measurement, and through analysis show that it can be compensated in a simple way. We demonstrate the effectiveness of this method and wakefield compensation through numerical simulations, including effects of coherent synchrotron radiation and longitudinal space charge. When used in conjunction with a high-resolution electron spectrometer, this method potentially reveals the temporal profile of the electron beam down to the femtosecond and subfemotsecond scale.
Date: August 26, 2010
Creator: Huang, Z.; Bane, K.; Ding, Y. & Emma, P.
Object Type: Article
System: The UNT Digital Library
SXR Continuum Radiation Transmitted Through Metallic Filters: An Analytical Approach To Fast Electron Temperature Measurements (open access)

SXR Continuum Radiation Transmitted Through Metallic Filters: An Analytical Approach To Fast Electron Temperature Measurements

A new set of analytic formulae describes the transmission of soft X-ray (SXR) continuum radiation through a metallic foil for its application to fast electron temperature measurements in fusion plasmas. This novel approach shows good agreement with numerical calculations over a wide range of plasma temperatures in contrast with the solutions obtained when using a transmission approximated by a single-Heaviside function [S. von Goeler, Rev. Sci. Instrum., 20, 599, (1999)]. The new analytic formulae can improve the interpretation of the experimental results and thus contribute in obtaining fast teperature measurements in between intermittent Thomson Scattering data.
Date: August 26, 2010
Creator: Delgado-Aparicio, L.; Tritz, K.; Kramer, T.; Stutman, D.; Finkentha, M.; Hill, K. et al.
Object Type: Report
System: The UNT Digital Library
'Micromanaging de Sitter holography' (open access)

'Micromanaging de Sitter holography'

We develop tools to engineer de Sitter vacua with semi-holographic duals, using elliptic fibrations and orientifolds to uplift Freund-Rubin compactifications with CFT duals. The dual brane construction is compact and constitutes a microscopic realization of the dS/dS correspondence, realizing d-dimensional de Sitter space as a warped compactification down to (d-1)-dimensional de Sitter gravity coupled to a pair of large-N matter sectors. This provides a parametric microscopic interpretation of the Gibbons-Hawking entropy. We illustrate these ideas with an explicit class of examples in three dimensions, and describe ongoing work on four-dimensional constructions. The Gibbons-Hawking entropy of the de Sitter horizon [1] invites a microscopic interpretation and a holographic formulation of inflating spacetimes. Much progress was made in the analogous problem in black hole physics using special black holes in string theory whose microstates could be reliably counted, such as those analyzed in [2,3]; this led to the AdS/CFT correspondence [4]. In contrast, a microscopic understanding of the entropy of de Sitter space is more difficult for several reasons including its potential dynamical connections to other backgrounds (metastability), the absence of a non-fluctuating timelike boundary, and the absence of supersymmetry. In this paper, we develop a class of de Sitter constructions in …
Date: August 26, 2010
Creator: Dong, Xi; Horn, Bart; /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP; Silverstein, Eva; /Santa Barbara, KITP /SLAC /Stanford U., Phys. Dept.; Torroba, Gonzalo et al.
Object Type: Article
System: The UNT Digital Library
RAPID SEPARATION METHOD FOR 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES (open access)

RAPID SEPARATION METHOD FOR 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES

A new rapid method for the determination of {sup 237}Np and Pu isotopes in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for large soil samples. The new soil method utilizes an acid leaching method, iron/titanium hydroxide precipitation, a lanthanum fluoride soil matrix removal step, and a rapid column separation process with TEVA Resin. The large soil matrix is removed easily and rapidly using this two simple precipitations with high chemical recoveries and effective removal of interferences. Vacuum box technology and rapid flow rates are used to reduce analytical time.
Date: July 26, 2010
Creator: Maxwell, S.; Culligan, B. & Noyes, G.
Object Type: Article
System: The UNT Digital Library
Topological Insulators and Nematic Phases from Spontaneous Symmetry Breaking in (open access)

Topological Insulators and Nematic Phases from Spontaneous Symmetry Breaking in

We investigate the stability of a quadratic band-crossing point (QBCP) in 2D fermionic systems. At the non-interacting level, we show that a QBCP exists and is topologically stable for a Berry flux {-+}2{pi}, if the point symmetry group has either fourfold or sixfold rotational symmetries. This putative topologically stable free-fermion QBCP is marginally unstable to arbitrarily weak shortrange repulsive interactions. We consider both spinless and spin-1/2 fermions. Four possible ordered states result: a quantum anomalous Hall phase, a quantum spin Hall phase, a nematic phase, and a nematic-spin-nematic phase.
Date: May 26, 2010
Creator: Sun, K.
Object Type: Article
System: The UNT Digital Library
AdS/CFT and Large-N Volume Independence (open access)

AdS/CFT and Large-N Volume Independence

We study the Eguchi-Kawai reduction in the strong-coupling domain of gauge theories via the gravity dual of N=4 super-Yang-Mills on R{sup 3} x S{sup 1}. We show that D-branes geometrize volume independence in the center-symmetric vacuum and give supergravity predictions for the range of validity of reduced large-N models at strong coupling.
Date: August 26, 2010
Creator: Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Realization of Center Symmetry in Two Adjoint Flavor Large-N Yang-Mills (open access)

Realization of Center Symmetry in Two Adjoint Flavor Large-N Yang-Mills

We report on the results of numerical simulations of SU(N) lattice Yang Mills with two flavors of (light) Wilson fermion in the adjoint representation. We analytically and numerically address the question of center symmetry realization on lattices with {Lambda} sites in each direction in the large-N limit. We show, by a weak coupling calculation that, for massless fermions, center symmetry realization is independent of {Lambda}, and is unbroken. Then, we extend our result by conducting simulations at non zero mass and finite gauge coupling. Our results indicate that center symmetry is intact for a range of fermion mass in the vicinity of the critical line on lattices of volume 2{sup 4}. This observation makes it possible to compute infinite volume physical observables using small volume simulations in the limit N {yields} {infinity}, with possible applications to the determination of the conformal window in gauge theories with adjoint fermions.
Date: August 26, 2010
Creator: Catterall, Simon; U., /Syracuse; Galvez, Richard; U., /Syracuse; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns (open access)

FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns

The problem of Network Traffic Classification (NTC) has attracted significant amount of interest in the research community, offering a wide range of solutions at various levels. The core challenge is in addressing high amounts of traffic diversity found in today's networks. The problem becomes more challenging if a quick detection is required as in the case of identifying malicious network behavior or new applications like peer-to-peer traffic that have potential to quickly throttle the network bandwidth or cause significant damage. Recently, Traffic Dispersion Graphs (TDGs) have been introduced as a viable candidate for NTC. The TDGs work by forming a network wide communication graphs that embed characteristic patterns of underlying network applications. However, these patterns need to be quickly evaluated for mounting real-time response against them. This paper addresses these concerns and presents a novel solution for real-time analysis of Traffic Dispersion Metrics (TDMs) in the TDGs. We evaluate the dispersion metrics of interest and present a dedicated solution on an FPGA for their analysis. We also present analytical measures and empirically evaluate operating effectiveness of our design. The mapped design on Virtex-5 device can process 7.4 million packets/second for a TDG comprising of 10k flows at very high accuracies …
Date: March 26, 2010
Creator: Khan, F.; Gokhale, M. & Chuah, C. N.
Object Type: Article
System: The UNT Digital Library
e+ e- Factory Developments (open access)

e+ e- Factory Developments

The impressive performance of current (KEKB) and recent (PEP-II) B-Factory colliders has increased interest in developing even higher luminosity B-factories. Two new designs are being developed (SuperKEKB and SuperB). Both designs plan to deliver a luminosity in the range of 1 x 10{sup 36} cm{sup -2}s{sup -1}, nearly 100 times the present B-factory level. Achieving this high luminosity requires high-current beams and short bunch lengths and/or a new way of colliding the beams. The SuperB design employs a crabbed magnetic waist with a large crossing angle and the SuperKEKB design is looking at crab cavities with high-current beams and/or a travelling focus. I describe the designs being studied to achieve the high luminosity needed for the next generation of B-Factories.
Date: August 26, 2010
Creator: Sullivan, Michael
Object Type: Article
System: The UNT Digital Library
Observation of the three-body rare decay B-> J/psi phi K (open access)

Observation of the three-body rare decay B-> J/psi phi K

The authors report the study of the B meson decays B{sup {+-}} {yields} J/{psi}{phi}K{sup {+-}}, B{sup 0} {yields} J/{psi}{phi}K{sup 0} using 433 million of B{bar B} events collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} asymmetric-energy collider. They obtain the branching fraction measurements: {Beta}(B{sup {+-}} {yields} J{psi}{phi}K{sup {+-}}) = (5.6 {+-} 0.9(stat) {+-} 0.3(sys)) x 10{sup -5}, {Beta}(B{sup {+-}} {yields} J{psi}{phi}K{sup 0}) = (5.4 {+-} 1.2(stat) {+-} 0.4(sys)) x 10{sup -5}.
Date: August 26, 2010
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Mechanics of Individual, Isolated Vortices in a Cuprate Superconductor (open access)

Mechanics of Individual, Isolated Vortices in a Cuprate Superconductor

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Date: May 26, 2010
Creator: Auslaender, O.M.
Object Type: Article
System: The UNT Digital Library
Conformality or confinement: (IR)relevance of topological excitations (open access)

Conformality or confinement: (IR)relevance of topological excitations

What distinguishes two asymptotically-free non-abelian gauge theories on R{sup 4}, one of which is just below the conformal window boundary and confines, while the other is slightly above the boundary and flows to an infrared conformal field theory? In this work, we aim to answer this question for non-supersymmetric Yang-Mills theories with fermions in arbitrary chiral or vectorlike representations. We use the presence or absence of mass gap for gauge fluctuations as an identifier of the infrared behavior. With the present-day understanding of such gauge theories, the mass gap for gauge fluctuations cannot be computed on R{sup 4}. However, recent progress allows its non-perturbative computation on R{sup 3} x S{sup 1} by using either the twisted partition function or deformation theory, for a range of sizes of S{sup 1} depending on the theory. For small number of fermions, N{sub f}, we show that the mass gap increases with increasing radius, due to the non-dilution of monopoles and bions - the topological excitations relevant for confinement on R{sup 3} x S{sup 1}. For sufficiently large N{sub f}, we show that the mass gap decreases with increasing radius. In a class of theories, we claim that the decompactification limit can be taken …
Date: August 26, 2010
Creator: Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Bigger, Better, Faster, More at the LHC (open access)

Bigger, Better, Faster, More at the LHC

Multijet plus missing energy searches provide universal coverage for theories that have new colored particles that decay into a dark matter candidate and jets. These signals appear at the LHC further out on the missing energy tail than two-to-two scattering indicates. The simplicity of the searches at the LHC contrasts sharply with the Tevatron where more elaborate searches are necessary to separate signal from background. The searches presented in this article effectively distinguish signal from background for any theory where the LSP is a daughter or granddaughter of the pair-produced colored parent particle without ever having to consider missing energies less than 400 GeV.
Date: August 26, 2010
Creator: Izaguirre, Eder; /SLAC; Manhart, Michael; /Rutgers U., Piscataway; Wacker, Jay G. & /SLAC
Object Type: Article
System: The UNT Digital Library
RegPredict: an integrated system for regulon inference in prokaryotes by comparative genomics approach (open access)

RegPredict: an integrated system for regulon inference in prokaryotes by comparative genomics approach

RegPredict web server is designed to provide comparative genomics tools for reconstruction and analysis of microbial regulons using comparative genomics approach. The server allows the user to rapidly generate reference sets of regulons and regulatory motif profiles in a group of prokaryotic genomes. The new concept of a cluster of co-regulated orthologous operons allows the user to distribute the analysis of large regulons and to perform the comparative analysis of multiple clusters independently. Two major workflows currently implemented in RegPredict are: (i) regulon reconstruction for a known regulatory motif and (ii) ab initio inference of a novel regulon using several scenarios for the generation of starting gene sets. RegPredict provides a comprehensive collection of manually curated positional weight matrices of regulatory motifs. It is based on genomic sequences, ortholog and operon predictions from the MicrobesOnline. An interactive web interface of RegPredict integrates and presents diverse genomic and functional information about the candidate regulon members from several web resources. RegPredict is freely accessible at http://regpredict.lbl.gov.
Date: May 26, 2010
Creator: Novichkov, Pavel S.; Rodionov, Dmitry A.; Stavrovskaya, Elena D.; Novichkova, Elena S.; Kazakov, Alexey E.; Gelfand, Mikhail S. et al.
Object Type: Article
System: The UNT Digital Library
Large-N reduction in QCD-like theories with massive adjoint fermions (open access)

Large-N reduction in QCD-like theories with massive adjoint fermions

Large-N QCD with heavy adjoint fermions emulates pure Yang-Mills theory at long distances. We study this theory on a four- and three-torus, and analytically argue the existence of a large-small volume equivalence. For any finite mass, center symmetry unbroken phase exists at sufficiently small volume and this phase can be used to study the large-volume limit through the Eguchi-Kawai equivalence. A finite temperature version of volume independence implies that thermodynamics on R3 x S1 can be studied via a unitary matrix quantum mechanics on S1, by varying the temperature. To confirm this non-perturbatively, we numerically study both zero- and one-dimensional theories by using Monte-Carlo simulation. Order of finite-N corrections turns out to be 1/N. We introduce various twisted versions of the reduced QCD which systematically suppress finite-N corrections. Using a twisted model, we observe the confinement/deconfinement transition on a 1{sup 3} x 2-lattice. The result agrees with large volume simulations of Yang-Mills theory. We also comment that the twisted model can serve as a non-perturbative formulation of the non-commutative Yang-Mills theory.
Date: August 26, 2010
Creator: Azeyanagi, Tatsuo; U., /Kyoto; Hanada, Masanori; Inst., /Weizmann; Unsal, Mithat; /Weizmann Inst. /SLAC /Stanford U., Phys. Dept. et al.
Object Type: Article
System: The UNT Digital Library
Massless versus Kaluza-Klein gravitons at the LHC (open access)

Massless versus Kaluza-Klein gravitons at the LHC

We show that the LHC will be able to differentiate between a four-dimensional model with quantum gravity at {approx} 1 TeV where the (massless) graviton becomes strongly coupled to standard model particles at 1 TeV and brane world type models with a large extra-dimensional volume and massive Kaluza-Klein gravitons. We estimate that the 14 TeV LHC could put a limit of the order of {approx} 5 TeV on the four dimensional Planck mass in a model independent way.
Date: August 26, 2010
Creator: Calmet, Xavier; U., /Sussex; de Aquino, Priscila; /Louvain U., CP3 /Leuven U.; Rizzo, Thomas G. & /SLAC
Object Type: Article
System: The UNT Digital Library
Observation of the decay B0bar -> LambdaC antiproton pi0 (open access)

Observation of the decay B0bar -> LambdaC antiproton pi0

In a sample of 467 million B{bar B} pairs collected with the BABAR detector at the PEP-II collider at SLAC we have observed the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup 0} and measured the branching fraction to be (1.94 {+-} 0.17 {+-} 0.14 {+-} 0.50) x 10{sup -4}, where the uncertainties are statistical, systematic, and the uncertainty on the {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} branching fraction, respectively. We determine an upper limit of 1.5 x 10{sup -6} at 90% C.L. for the product branching fraction {Beta}({bar B}{sup 0} {yields} {Sigma}{sub c}{sup +}(2455){bar p}) x {Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}). Furthermore, we observe an enhancement at the threshold of the invariant mass of the baryon-antibaryon pair.
Date: August 26, 2010
Creator: Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Object Type: Article
System: The UNT Digital Library
F-Theory Uplifts and GUTs (open access)

F-Theory Uplifts and GUTs

We study the F-theory uplift of Type IIB orientifold models on compact Calabi-Yau threefolds containing divisors which are del Pezzo surfaces. We consider two examples defined via del Pezzo transitions of the quintic. The first model has an orientifold projection leading to two disjoint O7-planes and the second involution acts via an exchange of two del Pezzo surfaces. The two uplifted fourfolds are generically singular with minimal gauge enhancements over a divisor and, respectively, a curve in the non-Fano base. We study possible further degenerations of the elliptic fiber leading to F-theory GUT models based on subgroups of E{sub 8}.
Date: August 26, 2010
Creator: Blumenhagen, Ralph; Grimm, Thomas W.; Jurke, Benjamin & Weigand, Timo
Object Type: Article
System: The UNT Digital Library
Axial Anomaly, Dirac Sea, and the Chiral Magnetic Effect (open access)

Axial Anomaly, Dirac Sea, and the Chiral Magnetic Effect

Gribov viewed the axial anomaly as a manifestation of the collective motion of Dirac fermions with arbitrarily high momenta in the vacuum. In the presence of an external magnetic field and a chirality imbalance, this collective motion becomes directly observable in the form of the electric current - this is the chiral magnetic effect (CME). I give an elementary introduction into the physics of CME, and discuss the experimental status and recent developments.
Date: May 26, 2010
Creator: Kharzeev, D.E.
Object Type: Article
System: The UNT Digital Library
11.424 Ghz Stripline Transversal Filter for Sub-Picosecond Bunch Timing Measurements (open access)

11.424 Ghz Stripline Transversal Filter for Sub-Picosecond Bunch Timing Measurements

Measurement of time-of-arrival or instantaneous longitudinal position is a fundamental beam diagnostic. We present results from a stripline transversal periodic coupler structure which forms the heart of a sub-ps beam timing detector. This filter structure approximates a sinx/x response in the frequency domain which corresponds to a limited pulse length response in the time domain. These techniques have been used extensively in beam feedback systems at 3 GHz center frequencies with operational single-shot resolutions of 200 fs [1]. We present a new design, based on a 11.424 GHz center frequency, which is intended to offer a factor of four improvement in time resolution. Two-dimensional electromagnetic simulation results are shown, and the design optimization approach leading to the final circuit implementation is illustrated. The prototype circuit has been fabricated on 64mil Rogers 4003 and lab frequency domain and time domain data are compared to the 2-D simulation results. Performance of the prototype circuit is shown with applicability to sub-ps beam measurements in LINAC and FEL applications.
Date: August 26, 2010
Creator: Van Winkle, D.; Young, A. & Fox, J. D.
Object Type: Article
System: The UNT Digital Library
Data Reduction Processes Using FPGA for MicroBooNE Liquid Argon Time Projection Chamber (open access)

Data Reduction Processes Using FPGA for MicroBooNE Liquid Argon Time Projection Chamber

MicroBooNE is a liquid Argon time projection chamber to be built at Fermilab for an accelerator-based neutrino physics experiment and as part of the R&D strategy for a large liquid argon detector at DUSEL. The waveforms of the {approx}9000 sense wires in the chamber are continuously digitized at 2 M samples/s - which results in a large volume of data coming off the TPC. We have developed a lossless data reduction scheme based on Huffman Coding and have tested the scheme on cosmic ray data taken from a small liquid Argon time projection chamber, the BO detector. For sense wire waveforms produced by cosmic ray tracks, the Huffman Coding scheme compresses the data by a factor of approximately 10. The compressed data can be fully recovered back to the original data since the compression is lossless. In addition to accelerator neutrino data, which comes with small duty cycle in sync with the accelerator beam spill, continuous digitized waveforms are to be temporarily stored in the MicroBooNE data-acquisition system for about an hour, long enough for an external alert from possible supernova events. Another scheme, Dynamic Decimation, has been developed to compress further the potential supernova data so that the storage …
Date: May 26, 2010
Creator: Wu, Jinyuan
Object Type: Article
System: The UNT Digital Library