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Nonlinear Statistical Signal Processing: A Particle Filtering Approach

Description: A introduction to particle filtering is discussed starting with an overview of Bayesian inference from batch to sequential processors. Once the evolving Bayesian paradigm is established, simulation-based methods using sampling theory and Monte Carlo realizations are discussed. Here the usual limitations of nonlinear approximations and non-gaussian processes prevalent in classical nonlinear processing algorithms (e.g. Kalman filters) are no longer a restriction to perform Bayesian inference. It … more
Date: September 19, 2007
Creator: Candy, J
Partner: UNT Libraries Government Documents Department
open access

STRANGENESS PRODUCTION AS A FUNCTION OF SYSTEM SIZE AND ENERGY OF RHIC.

Description: In this paper we report on strangeness measurements in p+p, Au+Au and Cu+Cu collisions at different energies in the STAR detector at RHIC. We will focus on two momentum regions in particular: Firstly we look at strangeness enhancement in A+A collisions with respect to p+p. These yields are dominated by low transverse momentum. We compare the enhancements from Au+Au and Cu+Cu data at {radical}s{sub NN} = 200 GeV with Pb+Pb data at {radical}s{sub NN} = 17.2 GeV and find that the enhancement does … more
Date: July 19, 2007
Creator: LAMONT,M.
Partner: UNT Libraries Government Documents Department
open access

Electron Beam Lifetime in SPEAR3: Measurement and Simulation

Description: In this paper we report on electron beam lifetime measurements as a function of scraper position, RF voltage and bunch fill pattern in SPEAR3. We then outline development of an empirical, macroscopic model using the beam-loss rate equation. By identifying the dependence of loss coefficients on accelerator and beam parameters, a numerically-integrating simulator can be constructed to compute beam decay with time. In a companion paper, the simulator is used to train a parametric, non-linear dynam… more
Date: December 19, 2007
Creator: Corbett, J.; Huang, X.; Lee, M. & Lui, P.
Partner: UNT Libraries Government Documents Department
open access

Fabrication of Pillar-Structured Thermal Neutron Detectors

Description: Pillar detector is an innovative solid state device structure that leverages advanced semiconductor fabrication technology to produce a device for thermal neutron detection. State-of-the-art thermal neutron detectors have shortcomings in achieving simultaneously high efficiency, low operating voltage while maintaining adequate fieldability performance. By using a 3-dimensional silicon PIN diode pillar array filled with isotopic boron 10, ({sup 10}B) a high efficiency device is theoretically pos… more
Date: November 19, 2007
Creator: Nikolic, R. J.; Conway, A. M.; Reinhardt, C. E.; Graff, R. T.; Wang, T. F.; Deo, N. et al.
Partner: UNT Libraries Government Documents Department
open access

Effects of Chromium(VI) and Chromium(III) on Desulfovibrio vulgaris Cells

Description: Desulfovibrio vulgaris ATCC 29579 is a well studied sulfate reducer that has known capabilities of reducing heavy metals and radionuclides, like chromium and uranium. Cultures grown in a defined medium (i.e. LS4D) had a lag period of approximately 40 h when exposed to 50 μMof Cr(VI). Substrate analysis revealed that although chromium is reduced within the first 5 h, growth does not resume for another 35 h. During this time, small amounts of lactate are still utilized but the reduction of sulfat… more
Date: April 19, 2007
Creator: Clark, M.E.; Klonowska, A.; Thieman, S.B.; Giles, B.; Wall, J.D. & Fields, and M.W.
Partner: UNT Libraries Government Documents Department
open access

Empirical evidence for a recent slowdown in irrigation-induced cooling

Description: Understanding the influence of past land use changes on climate is needed to improve regional projections of future climate change and inform debates about the tradeoffs associated with land use decisions. The effects of rapid expansion of irrigated area in the 20th century has remained unclear relative to other land use changes, such as urbanization, that affected a similar total land area. Using spatial and temporal variations in temperature and irrigation extent observed in California, we sh… more
Date: January 19, 2007
Creator: Bonfils, C & Lobell, D
Partner: UNT Libraries Government Documents Department
open access

Birth of Massive Black Hole Binaries

Description: If massive black holes (BHs) are ubiquitous in galaxies and galaxies experience multiple mergers during their cosmic assembly, then BH binaries should be common albeit temporary features of most galactic bulges. Observationally, the paucity of active BH pairs points toward binary lifetimes far shorter than the Hubble time, indicating rapid inspiral of the BHs down to the domain where gravitational waves lead to their coalescence. Here, we review a series of studies on the dynamics of massive BH… more
Date: November 19, 2007
Creator: Colpi, M.; Dotti, M.; Mayer, L. & Kazantzidis, S.
Partner: UNT Libraries Government Documents Department
open access

GENERATION OF SUBPICOSECOND X-RAY PULSES IN STORAGE RINGS

Description: Supicosecond x-ray pulses are routinely produced at ALS,BESSY and SLS with slicing technique and used in pump-probe experimentswith controlled delay between laser pump pulses and x-ray probe pulses.New development aiming for a production of a subpicosecond x-ray pulsesusing rf orbit deflection technique is under way at APS. Both techniqueswill be reviewed here.
Date: June 19, 2007
Creator: Zholents, Alexander A.
Partner: UNT Libraries Government Documents Department
open access

Performance and Accuracy of LAPACK's Symmetric TridiagonalEigensolvers

Description: We compare four algorithms from the latest LAPACK 3.1 release for computing eigenpairs of a symmetric tridiagonal matrix. These include QR iteration, bisection and inverse iteration (BI), the Divide-and-Conquer method (DC), and the method of Multiple Relatively Robust Representations (MR). Our evaluation considers speed and accuracy when computing all eigenpairs, and additionally subset computations. Using a variety of carefully selected test problems, our study includes a variety of today's co… more
Date: April 19, 2007
Creator: Demmel, Jim W.; Marques, Osni A.; Parlett, Beresford N. & Vomel, Christof
Partner: UNT Libraries Government Documents Department
open access

A comparison of DNA damage probes in two HMEC lines with X-irradiation

Description: In this study, we investigated {gamma}H2AX{sup ser139} and 53BP1{sup ser25}, DNA damage pathway markers, to observe responses to radiation insult. Two Human Mammary Epithelial Cell (HMEC) lines were utilized to research the role of immortalization in DNA damage marker expression, HMEC HMT-3522 (S1) with an infinite lifespan, and a subtype of HMEC 184 (184V) with a finite lifespan. Cells were irradiated with 50 cGy X-rays, fixed with 4% paraformaldehyde after 1 hour repair at 37 C, and processed… more
Date: January 19, 2007
Creator: Wisnewski, Christy L.; Bjornstad, Kathleen A.; Rosen, ChristoperJ.; Chang, Polly Y. & Blakely, Eleanor A.
Partner: UNT Libraries Government Documents Department
open access

Dynamics of Converging Laser-Created Plasmas in Semi-Cylindrical Cavities Studied using Soft X-Ray Laser Interferometry

Description: The evolution of dense aluminum and carbon plasmas produced by laser irradiation of 500 {micro}m diameter semi-cylindrical targets was studied using soft x-ray laser interferometry. Plasmas created heating the cavity walls with 120 picosecond duration optical laser pulses of {approx} 1 x 10{sup 12} W cm{sup -2} peak intensity were observed to expand and converge on axis to form a localized high density plasma region. Electron density maps were measured using a 46.9 nm wavelength tabletop capill… more
Date: September 19, 2007
Creator: Purvis, M. A.; Grava, J.; Filevich, J.; Marconi, M.; Dunn, J.; Moon, S. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Plasma Interactions in Laser Irradiated Semi-Cylindrical Cavities Studied with Soft X-Ray Interferometry Using a Capillary Discharge Laser

Description: Soft x-ray interferometry was used to measure the evolution of dense converging plasmas created by laser irradiation of 500 {micro}m diameter semi-cylindrical carbon targets. Optical laser pulses with an intensity of {approx} 1 x 10{sup 12} W cm{sup -2} and 120 ps duration were used to heat the surface of the cavities. The dense plasma formed expands from the walls converging slightly off the semi-cylinder's axis, giving rise to a bright localized high density plasma region. A sequence of elect… more
Date: September 19, 2007
Creator: Purvis, M. A.; Grava, J.; Filevich, J.; Marconi, M.; Rocca, J. J.; Moon, S. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Qcd Spin Physics in Hadronic Interactions.

Description: We discuss spin phenomena in high-energy hadronic scattering, with a particular emphasis on the spin physics program now underway at the first polarized proton-proton collider, RHIC. Experiments at RHIC unravel the spin structure of the nucleon in new ways. Prime goals are to determine the contribution of gluon spins to the proton spin, to elucidate the flavor structure of quark and antiquark polarizations in the nucleon, and to help clarify the origin of transverse-spin phenomena in QCD. These… more
Date: June 19, 2007
Creator: Vogelsang, W.
Partner: UNT Libraries Government Documents Department
open access

Hard QCD Processes at Colliders

Description: Recent developments in the study of hard QCD processes at colliders are reviewed, in the context of the imminent startup of the LHC.
Date: December 19, 2007
Creator: Dixon, Lance J.
Partner: UNT Libraries Government Documents Department
open access

ELLIPTIC FLOW, INITIAL ECCENTRICITY AND ELLIPTIC FLOW FLUCTUATIONS IN HEAVY ION COLLISIONS AT RHIC.

Description: We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu collisions provides evidence that the matter is created in the initial stage of relativistic heavy ion collisions with transverse granularity s… more
Date: February 19, 2007
Creator: Nouicer, R.; Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M. & Barton, D. S.
Partner: UNT Libraries Government Documents Department
open access

New advances in three-dimensional controlled-sourceelectromagnetic inversion

Description: New techniques for improving both the computational andimaging performance of the three dimensional (3D) electromagnetic inverseproblem are presented. A non-linear conjugate gradient algorithm is theframework of the inversion scheme. Full wave equation modelling forcontrolled sources is utilized for data simulation along with anefficient gradient computation approach for the model update. Improvingthe modelling efficiency of the 3D finite difference method involves theseparation of the potentia… more
Date: May 19, 2007
Creator: Commer, Michael & Newman, Gregory A.
Partner: UNT Libraries Government Documents Department
open access

Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States

Description: The authors present a search for the decays B{sup 0} {yields} e{sup +}e{sup -}, B{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}} using data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. Using a dataset corresponding to 384 x 10{sup 6} B{bar B} pairs, they do not find evidence of any of the three decay modes. They obtain upper limit on the branching fractions, at 90% confidence level, of {Beta}(B{sup 0} {yields} e{sup +… more
Date: December 19, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

Pre-symptomatic Prediction of Illness in Mice Inoculated with Cowpox

Description: We describe here research directed towards early (presyndromic) diagnosis of infection. By using a mouse model and a multi-component blood protein diagnostic tool we detected cowpox infection several days in advance of overt symptoms with high accuracy. We provide details of the experimental design and measurement technique and elaborate on the long-range implication of these results.
Date: April 19, 2007
Creator: Kercher, J R; Colston, Jr., B W; Langlois, R G; Lyons, C R & Milanovich, F P
Partner: UNT Libraries Government Documents Department
open access

An Integrated Method for Accurate Determination of Melting in High-Pressure Laser Heating Experiments

Description: We present an integrated approach for melting determination by monitoring several criteria simultaneously. In particular we combine x-ray diffraction observations with the detection of discontinuities in the optical properties by spectroradiometric measurements. This approach significantly increases the confidence of melt identification, especially with low-Z samples. We demonstrate the method with observations of melt in oxygen at 47 and 55 gigapascals.
Date: November 19, 2007
Creator: Benedetti, L R; Antonangeli, D; Farber, D L & Mezouar, M
Partner: UNT Libraries Government Documents Department
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