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Heavy and light hadron production and D-hadron correlation in relativistic heavy-ion collisions

NUCLEAR PHYSICS A 2017年 967卷 628-631页

作者： Cao, Shanshan Luo, Tan He, Yayun Qin, Guang-You Wang, Xin-Nian Wayne State Univ Dept Phys & Astron Detroit MI 48201 USA Lawrence Berkeley Natl Lab Nuclear Sci Div Berkeley CA 94720 USA Cent China Normal Univ Inst Particle Phys Wuhan 430079 Hubei Peoples R China Cent China Normal Univ Key Lab Quark & Lepton Phys MOE Wuhan 430079 Hubei Peoples R China

We establish a linear Boltzmann transport (LBT) model coupled to hydrodynamical background to study hard parton evolution in heavy-ion collisions. Both elastic and inelastic scatterings are included in our calculations;and heavy and light flavor partons are treated on the same footing. Within this LBT model, we provide good descriptions of heavy and light hadron suppression and anisotropic flow in heavy-ion collisions. angular correlation functions between heavy and light flavor hadrons are studied for the first time and shown able to quantify not only the amount of heavy quark energy loss, but also how the parton energy is re-distributed in parton showers.

关键词： relativistic nuclear collisions jet energy loss heavy quark angular correlation function

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Implementation of the two-point angular correlation function on a high-performance reconfigurable computer

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SCIENTIFIC PROGRAMMING 2009年第3期17卷 247-259页

作者： Kindratenko, Volodymyr V. Myers, Adam D. Brunner, Robert J. Univ Illinois Natl Ctr Supercomp Applicat Urbana IL 61801 USA Univ Illinois Dept Astron Urbana IL 61801 USA

We present a parallel implementation of an algorithm for calculating the two-point angular correlation function as applied in the field of computational cosmology. The algorithm has been specifically developed for a reconfigurable computer. Our implementation utilizes a microprocessor and two reconfigurable processors on a dual-MAP SRC-6 system. The two reconfigurable processors are used as two application-specific co-processors. Two independent computational kernels are simultaneously executed on the reconfigurable processors while data pre-fetching from disk and initial data pre-processing are executed on the microprocessor. The overall end-to-end algorithm execution speedup achieved by this implementation is over 90x as compared to a sequential implementation of the algorithm executed on a single 2.8 GHz Intel Xeon microprocessor.

关键词： Reconfigurable computing angular correlation function

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angular correlation functions of intensities scattered from two-layered randomly rough surface

Angular correlation functions of intensities scattered from ...

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3rd IEEE International Conference on Microwave Technology and Computational Electromagnetics (ICMTCE)

作者： Yang, Pengju Guo, Lixin Jia, Chungang Xidian Univ Sch Sci Xian 710071 Peoples R China

ISBN: (纸本)9781467363297;9781467363273

The intensity angular correlation properties of electromagnetic waves scattered from one-dimensional two-layered randomly rough surfaces is investigated by employing Monte Carlo technique accompanied by a parallel fast multiple method. The scattering surface integral equations are formulated by using Helmholtz equation and Green's theorem and then are converted into matrix equations by applying pulse basis functions and points matching. Numerical results are presented for both horizontal (HH) and vertical (VV) polarizations. The so-called memory effect, discussed elsewhere for dense random media, is encountered in two-layered randomly rough surfaces. The influences of roughness parameters of rough surfaces on the correlation functions are examined.

关键词： angular correlation function intensity fluctuation two-layered rough surface

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angular correlation functions of intensities scattered from two-layered randomly rough surface

Angular correlation functions of intensities scattered from ...

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International Conference on Microwave Technology & Computational Electromagnetics

作者： Pengju Yang Lixin Guo Chungang Jia School of science Xidian University Xi'an 710071 China

ISBN: (纸本)9781467363266

关键词： angular correlation function intensity fluctuation two-layered rough surface

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Cosmological calculations on the GPU

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ASTRONOMY AND COMPUTING 2013年 1卷 17-22页

作者： Bard, D. Bellis, M. Allen, M. T. Yeprernyan, H. Kratochvil, J. M. Kavli Inst Particle Astrophys & Cosmol Stanford CA 94309 USA Siena Coll Dept Phys & Astron Loudonville NY 12211 USA No Illinois Univ Dept Phys De Kalb IL 60115 USA Stanford Univ Dept Phys Stanford CA 94309 USA Foothill Coll Los Altos Hills CA 94022 USA Univ Miami Dept Phys Florida FL 33143 USA

Cosmological measurements require the calculation of nontrivial quantities over large datasets. The next generation of survey telescopes will yield measurements of billions of galaxies. The scale of these datasets, and the nature of the calculations involved, make cosmological calculations ideal models for implementation on graphics processing units (GPUs). We consider two cosmological calculations, the two-point angular correlation function and the aperture mass statistic, and aim to improve the calculation time by constructing code for calculating them on the GPU. Using CUDA, we implement the two algorithms on the GPU and compare the calculation speeds to comparable code run on the CPU. We obtain a code speed-up of between 10 and 180x faster, compared to performing the same calculation on the CPU. The code has been made publicly available. GPUs are a useful tool for cosmological calculations, even for datasets the size of current surveys, allowing calculations to be made one or two orders of magnitude faster. (c) 2012 Elsevier B.V. All rights reserved.

关键词： Cosmological calculations Aperture mass angular correlation function GPU CUDA Scientific computation Cosmology

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Experimental studies on circular SAR imaging in clutter using angular correlation function technique

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 1999年第5期37卷 2192-2197页

作者： Chan, TK Kuga, Y Ishimaru, A Univ Washington Dept Elect Engn Seattle WA 98195 USA

This paper describes a novel approach for three-dimensional (3-D) imaging in a heavy-clutter environment. The proposed approach consists of two techniques, The first calls for the use of a synthetic aperture radar (SAR) moving in a circular orbit, whereas the second involves using angular correlation function (ACF) measurement for achieving clutter suppression. To demonstrate the imaging and clutter suppression capabilities of this combined approach (circular-correlation SAR), microwave imaging experiments are conducted at X-band frequencies (7-13 GHz). It is found that in heavy-clutter environments, this combined SAR approach outperforms conventional SAR, resulting in clearer images with enhanced target-to-clutter ratio.

关键词： angular correlation function circular synthetic aperture radar clutter suppression confocal imaging correlation techniques frequency correlation function target detection 3-D image reconstruction

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Numerical studies of the detection of targets embedded in clutter by using angular correlation function and angular correlation imaging

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 1998年第2期17卷 82-86页

作者： Zhang, GF Tsang, L Kuga, Y Univ Washington Dept Elect Engn Electromagnet & Remote Sensing Lab Seattle WA 98195 USA

We study a detection method for targets embedded in a clutter environment based on the 3-D angular correlation function (ACF). The clutter is modeled by randomly distributed small scatterers. The total scattered wave field at the receiver is calculated using Monte Carlo simulations, and is used for the calculation of ACF and angular correlation imaging. The angular correlation imaging consists of calculating the angular correlation function with focusing on desired locations. Compared with the traditional SAR (field) imaging, the correlation imaging has two advantages: 1) it has finer resolution than the field imaging, and 2) it can smear the speckle due to random scattering to make the target more conspicuous. We will show the angular correlation imaging method can be added to synthetic aperture radar (SAR) systems to make them more effective in obtaining information about the targets and suppressing clutter. We will also discuss general methods of correlation imaging. (C) 1998 John Wiley & Sons, Inc.

关键词： wave scattering target detection clutter angular correlation function correlation imaging

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The angular correlation function of wave scattering by a buried object embedded in random discrete scatterers under a random rough surface

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Microwave and Optical Technology Letters 1998年第3期14卷

作者： Guifu Zhang Leung Tsang Yasuo Kuga Electromagnetics and Remote Sensing Laboratory Department of Electrical Engineering Box 352500 University of Washington Seattle Washington 98195

Radar detection of a target embedded in geophysical media can be obscured by clutter. In this article the angular correlation function (ACF) is studied for wave scattering by an object embedded in random discrete scatterers under a rough surface. The ACF is calculated by using realization averaging, frequency averaging, and angular averaging. The results of the ACF for volume scattering, combined volume, and rough surface scattering and with a buried object are shown and compared. It is found that the ACF can be used to distinguish scattering by random discrete scatterers, random rough surface, and a deterministic buried object. The clutter return can be suppressed and the target becomes conspicuous. The ratio of ACF of the scattered wave with a target and that without a target can be 10 dB larger than the ratio of intensities. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 14, 144–151, 1997

关键词： angular correlation function wave scattering buried object random discrete scatterers rough surface

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Broadband bistatic coherent and incoherent detection of buried objects beneath randomly rough surfaces

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2000年第2期38卷 891-898页

作者： O'Neill, K USA Cold Reg Res & Engn Lab Hanover NH 03755 USA

This paper investigates the application of angular correlation function (ACF) processing for target detection when a metallic object beneath a randomly rough soil surface is sought by ground penetrating radar (GPR). ACF processing is an inherently coherent and multistatic approach. Here we compare its results;to those from candidate multistatic incoherent processing strategies. In 2-D numerical simulations, we assume that the antennas are elevated above the soil surface, and that the only significant source of environmental randomness is the soil surface roughness. To expand the basis for the ACF, averaging is performed over both frequency and limited spatial shift. We take pains to use realistic GPR problem parameters, together with relevant and varied target geometries. Results are evaluated over an ensemble of geometrical realizations to gain some statistical picture of each method's behavior and performance. Under the parameter limitations applied here, combined frequency and spatial averaging are required to produce recognizable ACF behavior Contrary to expectations, the ACF processing performs best in the vicinity of the "memory line," not when we avoid it.

关键词： angular correlation function buried objects ground penetrating radar (GPR) radar rough surface subsurface

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The angular correlation function of wave scattering by a buried object embedded in random discrete scatterers under a random rough surface

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 1997年第3期14卷 144-151页

作者： Zhang, GF Tsang, L Kuga, Y Electromagnetics and Remote Sensing Laboratory Department of Electrical Engineering Box 352500 University of Washington Seattle Washington 98195

Radar detection of a target embedded in geophysical media can be obscured by clutter. In this article the angular correlation function (ACF) is studied for wave scattering by an object embedded in random discrete scatterers under a rough surface. The ACF is calculated by using realization averaging, frequency averaging, and angular averaging. The results of the ACF for volume scattering combined volume, and rough surface scattering and with a buried object are shown and compared. It is found that the ACF can be used to distinguish scattering by random discrete scatterers, random rough surface, and a deterministic buried object. The chatter return can be suppressed and the target becomes conspicuous. The ratio of ACF of the scattered wave with a target and that without a target can be 10 dB larger than the ratio of intensities. (C) 1996 John Wiley & Sons, Inc.

关键词： angular correlation function wave scattering buried object random discrete scatterers rough surface

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