Multi-scale HPC system for multi-scale discrete simulation-Development and application of a supercomputer with 1 Petaflops peak performance in single precision

mputing mode. The preliminary applications of this machine in areas of multi-phase flow, molecular dynamics and so on are reported, demonstrating the supercomputer as a paradigm of green computation in new architecture.     

Signed graphs and the freeness of the Weyl subarrangements of type Bℓ

A Weyl arrangement is the hyperplane arrangement defined by a root system. Saito proved that every Weyl arrangement is free. The Weyl subarrangements of type $A_{\ell }$ are represented by simple graphs. Stanley gave a characterization of freeness for this type of arrangements in terms of their graph. In addition, the Weyl subarrangements of type $B_{\ell }$ can be represented by signed graphs. A characterization of freeness for them is not known. However, characterizations of freeness for a few restricted classes are known. For instance, Edelman and Reiner characterized the freeness of the arrangements between type $A_{\ell -1}$ and type $B_{\ell }$. In this paper, we give a characterization of the freeness and supersolvability of the Weyl subarrangements of type $B_{\ell }$ under certain assumption.     

ʵʱ����ƽ�ⷴ�ݳ�����EAST PCS�еļ���

为提高等离子体实时平衡反演过程的精度和效率,开发了基于图形处理器(GPU)的P-EFIT程序.简要概括EAST PCS软硬件架构后,描述了并行实时平衡反演程序P-EFIT在EAST PCS中的集成工作.为了验证集成系统的正确性与可用性,用历史实验数据作了性能测试,满足实时控制的要求.目前P-EFIT已集成在EAST中并用于等离子体控制,EAST实验证明控制性能良好.     

在GPU上求解大规模优化问题的反向策略的PSO算法

本文通过对传统粒子群算法(PSO)的分析,在GPU(Graphic Process Unit)上设计了基于一般反向学习策略的粒子群算法,并用于求解大规模优化问题.主要思想是通过一般反向学习策略转化当前解空间,提高算法找到最优解的几率,同时使用GPU大量线程并行来加速收敛速度.对比数值实验表明,对于求解大规模高维的优化问题,本文算法比其他智能算法具有更好的精度和更快的收敛速度.     

“现代谱分析图形软件系统”的一些应用

“现代谱分析图形软件系统”是一个以谱分析为主体的大型软件，它包括了３２种当前典型的现代谱分析方法、经典谱分析方法和其它常用信号分析方法，并具有丰富的图形处理功能。本文介绍了该软件系统的基本功能和主要特点，研究了它在现代谱分析、水声、医疗、语音分析等领域的应用，并分析了有关结果。     

Brascamp-Lieb inequality for positive double John basis and its reverse

In this paper, we establish the Brascamp-Lieb inequality for positive double John basis and its reverse. As their applications, we estimate the upper and lower bounds for the volume product of two unit balls with the given norms. Moreover, the Loomis-Whitney inequality for positive double John basis is obtained.     

Discrete dipole approximation simulations on GPUs using OpenCL—Application on cloud ice particles

The global distribution and climatology of ice clouds are among the main uncertainties in climate modeling and prediction. In order to retrieve ice cloud properties from remote sensing measurements, the scattering properties of all cloud ice particle types must be known. The discrete dipole approximation (DDA) simulates scattering of radiation by arbitrarily shaped particles and is thus suitable for cloud ice crystals. The DDA models the particle as a collection of equal dipoles on a lattice, and is computationally much more expensive than approximations restricted to more regularly shaped particles. On a single computer the calculation for an ice particle of a specific size, for a given scattering plane at one specific wavelength can take several days. We have ported the core routines of the scattering suite “ADDA” to the open computing language (OpenCL), a framework for programming parallel devices like PC graphics cards (graphics processing units, GPUs) or multi-core CPUs. In a typical case we can achieve a speed-up on a GPU as compared to a CPU by a factor of 5 in double precision and a factor of 15 in single precision. Spreading the work load over multiple GPUs will allow calculating the scattering properties even of large cloud ice particles.     

扫描隧道显微镜图象的重构

扫描隧道显微镜(STM)图象的解析，是STM应用的关键问题之一，STM的原始图象不能适应各种需要，而采用各种方法重构后，可以适应不同的应用。本文介绍了6种不同的重构方法。