检索结果-内蒙古大学图书馆

performance Optimization and Comparison of the Alternating Direction Implicit CFD Solver on Multi-core and Many-Core Architectures

引用

Chinese Journal of Electronics 2018年第3期27卷 540-548页

作者： DENG Liang ZHAO Dan BAI Hanli WANG Fang Computational Aerodynamics Institue China Aerodynamics Research and Development Center Collaborative Innovation Center of High Performance Computing National University of Denfense Technology School of Computer National University of Denfense Technology

We accelerate a double precision Alternating direction implicit(ADI) solver for three-dimensional compressible Navier-Stokes equations from our in-house Computational fluid dynamics(CFD) software on the latest multi-core and many-core architectures(Intel Sandy Bridge CPUs, Intel Many integrated core(MIC) coprocessors and NVIDIA Kepler K20c GPUs). Some performance optimization techniques are detailed discussed. We provide an in-depth analysis on the performance difference between Sandy Bridge and MIC. Experimental results show that the proposed GPU-enabled ADI solver can achieve a speedup of 5.5 on a Kepler GPU in contrast to two Sandy Bridge CPUs and our optimization techniques can improve the performance of the ADI solver by 2.5-fold on two Sandy Bridge CPUs and 1.7-fold on an Intel MIC coprocessor. We perform a cross-platform performance analysis(between GPU and MIC), which serves as case studies for developers to select the right accelerators for their target applications.

关键词： Multi-block Structured grid Alternating direction implicit(ADI) CFD solver Sandy bridge MIC GPU Optimization techniques performance comparison

来源：评论

学校读者我要写书评

暂无评论

Advances in simulated modeling of vibration systems based on computational intelligence

引用

自然科学进展(英文版) 2002年第12期12卷 881-886页

作者： LIANG Yanchun LEE Heow Pueh LIN Wuzhong LIM Siak Piang LEE Kwok Hong Zhou Chunguang College of Computer Science and Technology Jilin University Changchun 130012 China Institute of High Performance Computing Singapore 117528 Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sci Institute of High Performance Computing Singapore 117528 Department of Mechanical Engineering National University of Singapore Singapore 119260 Singapore College of Computer Science and Technology Jilin University Changchun 130012 China

Computational intelligence is the computational simulation of the bio-intelligence, which includes artificial neural networks, fuzzy systems and evolutionary computations. This article summarizes the state of the art in the field of simulated modeling of vibration systems using methods of computational intelligence, based on some relevant subjects and the authors' own research work. First, contributions to the applications of computational intelligence to the identification of nonlinear characteristics of packaging are reviewed. Subsequently, applications of the newly developed training algorithms for feedforward neural networks to the identification of restoring forces in multi-degree-of-freedom nonlinear systems are discussed. Finally, the neural-network-based method of model reduction for the dynamic simulation of microelectromechanical systems (MEMS) using generalized Hebbian algorithm (GHA) and robust GHA is outlined. The prospects of the simulated modeling of vibration systems using techniques of computational intelligence are also indicated.

关键词： computational intelligence artificial neural network fuzzy system evolutionary computation vibration system

来源：评论

学校读者我要写书评

暂无评论

Improving the spectral purity of single photons by a single-interferometer-coupled microring

引用

Chinese Physics B 2022年第3期31卷 311-315页

作者： Yang Wang Pingyu Zhu Shichuan Xue Yingwen Liu Junjie Wu Xuejun Yang Ping Xu Institute for Quantum Information & State Key Laboratory of High Performance Computing College of Computer Science and TechnologyNational University of Defense TechnologyChangsha 410013China

We experimentally engineer a high-spectral-purity single-photon source using a single-interferometer-coupled silicon microring. By the reconfiguration of the interferometer, different coupling conditions can be obtained, corresponding to different quality factors for the pump and signal/idler. The ratio between the quality factor of the pump and signal/idler ranges from 0.29 to 2.57. By constructing the signal–idler joint spectral intensity, we intuitively demonstrate the spectral correlation of the signal and idler. As the ratio between the quality factor of the pump and signal/idler increases, the spectral correlation of the signal and idler decreases, i.e., the spectral purity of the signal/idler photons increases. Furthermore,time-integrated second-order correlation of the signal photons is measured, giving a value up to 94.95 ± 3.46%. Such high-spectral-purity photons will improve the visibility of quantum interference and facilitate the development of on-chip quantum information processing.

关键词： spectral-purity microring asymmetric Mach–Zehnder interferometer

来源：评论

学校读者我要写书评

暂无评论

An effective and practical performance prediction model for parallel computing on nondedicated heterogeneous NOW

引用

JOURNAL OF PARALLEL AND DISTRIBUTED computing 1996年第1期38卷 63-80页

作者： Yan, Y Zhang, XD Song, YS [a] High Performance Computing and Software Laboratory The University of Texas at San Antonio San Antonio Texas 78249 [b] Jiangnan Institute of Computing Technology Jiangxu Province People's Republic of China

Networks of workstations (NOW) are receiving increased attention as a viable platform for high performance parallel computations. Heterogeneity and time-sharing are two characteristics that distinguish the NOW systems from conventional multiprocessor/multicomputer systems which are homogeneous and dedicated. It is important to have a practical model for users to predict the execution times of large-scale parallel applications on nondedicated heterogeneous NOW. Another objective of this study is to provide insight into the dynamic performance of parallel computing and into the effects of program structures and system factors on such a platform. In this paper, we study performance predictions for parallel computing on nondedicated heterogeneous networks of workstations. Our approach is based on a two-level model. On the top level, a semideterministic task graph is used to capture the parallel execution behavior including the variances of communication and synchronization. On the bottom level, a discrete time model is used to quantify effects from NOW systems. An iterative process is used to determine the interactive effects between network contention and task execution. We validate the prediction model using experiments on a nondedicated heterogeneous NOW. The maximum differences between predicted results and measured results were less than 10% in most cases and 15% in the worst cases. (C) 1996 Academic Press, Inc.

关键词：

来源：评论

学校读者我要写书评

暂无评论

New algorithms for performance trace analysis based on compressed complete call graphs

New algorithms for performance trace analysis based on compr...

引用

5th International Conference on Computational Science, ICCS 2005

作者： Knüpfer, Andreas Nagel, Wolfgang E. Center for High Performance Computing Dresden University of Technology Germany

ISBN: (纸本)9783540260431

This paper addresses performance and scalability issues of state-of-the-art trace analysis. The Complete Call Graph (CCG) data structure is proposed as an alternative to the common linear storage schemes. By transparent in-memory compression CCGs are capable of exploiting redundancy as frequently found in traces and thus reduce the memory requirements notably. Evaluation algorithms can be designed to take advantage of CCGs, too, such that the computational effort is reduced in the same order of magnitude as the memory requirements. © Springer-Verlag Berlin Heidelberg 2005.

关键词： Trace analysis

来源：评论

学校读者我要写书评

暂无评论

Spin Correlations in the Parent Phase of Li1−xFexODFeSe

引用

Physical Review Letters 2025年第1期134卷 016501-016501页

作者： Hongliang Wo Bingying Pan Die Hu Yu Feng A. D. Christianson Jun Zhao State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 China College of Physics and Optoelectronic Engineering Ocean University of China Qingdao Shandong 266100 China Institute of High Energy Physics Chinese Academy of Sciences (CAS) Beijing 100049 China Spallation Neutron Source Science Center Dongguan 523803 China Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Shanghai Research Center for Quantum Sciences Shanghai 201315 China Institute of Nanoelectronics and Quantum Computing Fudan University Shanghai 200433 China

Elucidating spin correlations in the parent compounds of high-temperature superconductors is crucial for understanding superconductivity. We used neutron scattering to study spin correlations in Li1−xFexODFeSe, an insulating material with reduced electron carriers compared to its superconducting counterpart (Tc=41 K), serving as the undoped parent compound. Our findings show a reduced total fluctuating moment in this insulator relative to FeSe and 122 iron pnictides, likely due to increased interlayer distances from intercalation, which enhance fluctuations and reduce the intensity of spin excitations. Moreover, we observed a V-shaped spin wavelike excitation dispersion, contrasting with the twisted hourglass pattern in the superconducting counterpart. Electron doping shifts spin excitation from (π,0) point to an incommensurate position towards (π,π) direction below 65 meV. This transition from V-shaped to hourglasslike dispersion, akin to behaviors in hole-doped cuprates, suggests a potential shared mechanism in magnetism and superconductivity across these diverse systems.

关键词： Neutron scattering

来源：评论

学校读者我要写书评

暂无评论

A Hybrid MPI+PGAS Approach to Improve Strong Scalability Limits of Finite Element Solvers 22

A Hybrid MPI+PGAS Approach to Improve Strong Scalability Lim...

引用

22nd IEEE International Conference on Cluster computing, CLUSTER 2020

作者： Jansson, Niclas Pdc Center for High Performance Computing Kth Royal Institute of Technology Stockholm Sweden

ISBN: (数字)9781728166773

ISBN: (纸本)9781728166773

Current finite element codes scale reasonably well as long as each core has sufficient amount of local work that can balance communication costs. However, achieving efficient performance at exascale will require unreasonable large problem sizes, in particular for low-order methods, where the small amount of work per element already is a limiting factor on current post petascale machines. Key bottlenecks for these methods are sparse matrix assembly, where communication latency starts to limit performance as the number of cores increases, and linear solvers, where efficient overlapping is necessary to amortize communication and synchronization cost of sparse matrix vector multiplication and dot products. We present our work on improving strong scalability limits of message passing based general low-order finite element based solvers. Using lightweight one-sided communication offered by partitioned global address space languages (PGAS), we demonstrate that the scalability of performance critical, latency sensitive sparse matrix assembly can achieve almost an order of magnitude better scalability. Linear solvers are also addressed via a signaling put algorithm for low-cost point-to-point synchronization, achieving similar performance as message passing based linear solvers. We introduce a new hybrid MPI+PGAS implementation of the open source general finite element framework FEniCS, replacing the linear algebra backend with a new library written in Unified Parallel C (UPC). A detailed description of the implementation and the hybrid interface to FEniCS is given, and the feasibility of the approach is demonstrated via a performance study of the hybrid implementation on Cray XC40 machines. © 2020 IEEE.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

Spectro-polarimetry of GRB 180427A: evidence for distinct emission sites with varying polarisation

arXiv

引用

arXiv 2025年

作者： Sonawane, Rushikesh Iyyani, Shabnam Gupta, Soumya Chattopadhyay, Tanmoy Bhattacharya, Dipankar Bhalerao, Varun B. Vadawale, Santosh V. Dewangan, G.C. Centre for High Performance Computing Indian Institute of Science Education and Research Thiruvananthapuram Thiruvananthapuram695551 India School of Physics Indian Institute of Science Education and Research Thiruvananthapuram Thiruvananthapuram695551 India Homi Bhabha National Institute Anushakti Nagar Maharashtra Mumbai400094 India Kavli Institute of Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Department of Physics Ashoka University Haryana Sonepat131029 India Indian Institute of Technology Bombay Mumbai India Physical Research Laboratory Gujarat Ahmedabad380009 India Inter-University Center for Astronomy and Astrophysics Maharashtra Pune411007 India

The dynamics of the origin of gamma-ray emissions in gamma-ray bursts (GRBs) remains an enigma. Through a joint analysis of GRB 180427A, observed by the Fermi Gamma-ray Space Telescope and AstroSat’s Cadmium Zinc Telluride Imager, we identify emissions from two distinct regions with varying polarisation properties. Time-resolved polarisation analysis reveals a synchronous evolution of the polarisation angle (PA) and fraction (PF) with two emission pulses, peaking with a delay of 4.82 ± 0.12 s. Spectral analysis indicates that the first pulse is dominated by blackbody radiation, while the second pulse exhibits a non-thermal spectrum (power law with an exponential cutoff). Using a bottom-to-top approach through simulations, we decouple the polarisation properties of the individual spectral components, revealing polarisation fractions of 25% - 40% for the blackbody spectrum and 30% - 60% for the non-thermal spectrum. At a redshift of z ∼ 0.05, the blackbody emission originates from the jet photosphere at 1011 cm, whereas the non-thermal emission arises from an optically thin region at 1015 cm. The changing dominance of these emissions explains the observed PA shift of 60◦ ±22.3◦. The spectral cutoff at 1 MeV suggests pair opacity due to the jet’s low bulk Lorentz factor (Γ ∼ tens). The high polarisation and hard spectral slopes (α > −0.5) imply a top-hat jet structure observed off-axis, near the jet’s edge. This off-axis viewing introduces anisotropy in the radiation within the viewing cone (1/Γ), accounting for the observed polarisation. © 2025, CC BY.

关键词： Gamma rays

来源：评论

学校读者我要写书评

暂无评论

Multivariate Oblivious Polynomial Evaluation Protocol

引用

电子学报(英文版) 2007年第2期16卷 217-222页

作者： XIAO Mingjun HUANG Liusheng LIU An HAN Kai Department of Computer Science and Technology University of Science and Technology of China Hefei 230027 China National High Performance Computing Center at Hefei Hefei 230027 China

Oblivious polynomial evaluation protocol is one of the fundamental protocols in secure multi-party computation domain. The existing oblivious polynomial evaluation protocol, only handling the univariate polynomial evaluation problems, is not enough to meet the demands in practice. In this paper, we propose a multivariate oblivious polynomial evaluation protocol depending on secure two-party scalar product protocol and homomorphic encryption scheme. To the best of our knowledge, this protocol is the first one to cope with both the univariate and multivariate oblivious polynomial evaluation problems. When we use our protocol and the existing one to solve the univariate oblivious polynomial evaluation problem, the performance analysis shows that at a same security level, the communication and computational overheads of our protocol are approximate O(1/ √|N| log |N|) times of those of the existing protocol, where |N| is the number of bits of the modulus N of the public key encryption schemes used in the two protocols.

关键词：多变量不经意多项式估值协议安全多方计算隐私保护

来源：评论

学校读者我要写书评

暂无评论

Privacy-preserving Matrix Rank Computation and Its Applications

引用

电子学报(英文版) 2008年第3期17卷 481-486页

作者： YAO Yifei HUANG Liusheng LUO Yonglong XU Weijiang JING Weiwei Department of Computer Science and Technology University of Science and Technology of China Hefei 230027 China National High Performance Computing Center at Hefei Hefei 230027 ChinaI

Matrix rank is an important tool for mathematical analysis, it is hard to compute cooperatively in an insecure distributed network. For the purpose to solve this problem, we put forward a privacy-preserving rank computation protocol for the first time. In this paper, the pro-rata protocol is improved to an optimal complexity of O(m) through comparing the collective information to reduce the round number, it performs better when the disproportional pairs distribute dispersedly or appear at later part of the sequence. Then, we propose a protocol to calculate matrix rank by the help of privacy-preserving technology, this protocol implements securely step by step according to the procedure in linear algebra. The protocol achieves the goal in secure two-party model without leaking other message. After that, their applications in mean square error and square sum error are considered. At last, we analyze all the protocols appeared in this paper to investigate their correctness, complexity and security by means of mathematical induction and cryptographic primitive.

关键词：矩阵秩计算标量积协议等量测试协议交叉协议

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：