Tausworthe非相关均匀随机数的简单生成方法

为提高Tausworthe均匀随机数(TURN)的生成速度,提出了一种可快速配置、并行输出非相关TURN序列的简单生成方法。该方法利用线性反馈移位寄存器结构特点,采用优化的输出生成矩阵,可高速并行输出非相关TURN序列。在不增加寄存器等资源前提下,同时采取两组优化的输出矩阵,可生成满足应用质量要求的非相关TURN序列对,所需硬件资源仅为组合Tausworthe结构和一步多跳算法的27.4%和48.8%,该优势随输出非相关TURN序列个数的增多而更趋显著。     

基于宽带DRFM的雷达面目标回波模拟技术

针对跳频雷达高度表大地面目标回波信号的模拟,提出了一种基于宽带数字射频存储(DRFM)技术的实现方案。首先介绍了1.2 GHz带宽、3 GHz采样的宽带DRFM组件硬件平台,然后重点叙述了基于DRFM技术的雷达高度表大地面目标回波模拟的算法设计方案,通过采用多路并行处理、多相滤波、正交调制等技术实现了数字下变频、目标回波特征调制、数字上变频等关键算法,最后给出了算法仿真和硬件调试结果,验证了算法的正确性和有效性。该方案已成功应用到某宽带跳频雷达高度表大地面目标回波模拟系统的设计中。     

基于TS201的软件优化设计

数据实时处理能力是雷达信号处理等实时系统的重要指标,提高软件运行效率是系统软件设计中必须要考虑的问题。大批量数据读取和存储操作存在于信号处理各工作阶段,对其进行充分优化是信号处理软件设计的重要组成部分。在此以ADSP TS201平台数据转存为例,描述了软件优化的设计思路和处理方法,运行结果表明,充分应用DSP并行处理特性和宽数据操作,采用汇编语言编程,可以使软件运行效率得到显著提高。     

基于并行FDTD方法分析表面等离子波导的特性

设计了一种双L形表面等离子体矩形环谐振器波导,采用并行时域有限差分方法,对这种波导的传输特性随几何结构参数的依赖关系进行了分析.计算结果表明通过改变输入/输出光波导的结构参数,可以调节该波导的消光比和频率选择特性.该波导结构能够有效地抑制后向辐射干扰并且大幅度地提高其场消光比,这使得此类谐振器结构更具有功能性.     

基于图像处理的海面动目标DP 相参检测方法

海面动目标检测是对海搜索雷达的一种重要工作模式,由于受海杂波影响,采用常规的非相参处理检测动目标时效果不佳。文中提出了一种基于图像处理的低重复频率DP 相参检测动目标的方法。该方法利用图像分割提取技术,针对二维频谱图运用sobel 算子提取边界,将杂波区和清晰区精确分开,提高了海面动目标的检测能力,并通过实测数据证明了该方法有效性和可实现性。     

Continuous development of schemes for parallel computing of the electrostatics in biological systems: Implementation in DelPhi

Due to the enormous importance of electrostatics in molecular biology, calculating the electrostatic potential and corresponding energies has become a standard computational approach for the study of biomolecules and nano‐objects immersed in water and salt phase or other media. However, the electrostatics of large macromolecules and macromolecular complexes, including nano‐objects, may not be obtainable via explicit methods and even the standard continuum electrostatics methods may not be applicable due to high computational time and memory requirements. Here, we report further development of the parallelization scheme reported in our previous work (Li, et al., J. Comput. Chem. 2012, 33, 1960) to include parallelization of the molecular surface and energy calculations components of the algorithm. The parallelization scheme utilizes different approaches such as space domain parallelization, algorithmic parallelization, multithreading, and task scheduling, depending on the quantity being calculated. This allows for efficient use of the computing resources of the corresponding computer cluster. The parallelization scheme is implemented in the popular software DelPhi and results in speedup of several folds. As a demonstration of the efficiency and capability of this methodology, the electrostatic potential, and electric field distributions are calculated for the bovine mitochondrial supercomplex illustrating their complex topology, which cannot be obtained by modeling the supercomplex components alone. © 2013 Wiley Periodicals, Inc.     

PHI: A powerful new program for the analysis of anisotropic monomeric and exchange‐coupled polynuclear d‐ and f‐block complexes

A new program, PHI, with the ability to calculate the magnetic properties of large spin systems and complex orbitally degenerate systems, such as clusters of d‐block and f‐block ions, is presented. The program can intuitively fit experimental data from multiple sources, such as magnetic and spectroscopic data, simultaneously. PHI is extensively parallelized and can operate under the symmetric multiprocessing, single process multiple data, or GPU paradigms using a threaded, MPI or GPU model, respectively. For a given problem PHI is been shown to be almost 12 times faster than the well‐known program MAGPACK, limited only by available hardware. © 2013 Wiley Periodicals, Inc.     

Du Fort-Frankel格式及DFF-I并行格式的稳定性

 本文对抛物型方程的Du Fort-Frankel(DFF)格式以及基于该格式构造的并行差分格式(DFF-I)进行了稳定性分析。采用矩阵分析方法, 证明了其无条件(LR)稳定性, 给出了DFF格式的稳定性系数的最小值的上界估计, 结果表明其与网格比有关, 从而DFF格式并非绝对稳定。本文改进了并行差分格式(DFF-I)的稳定性分析结果, 证明了其增长矩阵的谱半径严格小于1, 从而具有长时间稳定性。数值算例验证了DFF-I格式具有空间二阶精度, 且有很好的稳定性。     

复射影空间CP~((n+p)/2)中具有2-调和的一般子流形

本文研究了复射影空间中具有2-调和的一般子流形问题.利用活动标架法,获得了这类子流形成为极小子流形的Pinching定理和Simons型积分不等式,此外还得到关于2-调和伪脐一般子流形的一个刚性定理,推广了复射影空间中具有2-调和全实子流形的一些相应结果.     

Integrating open‐source software applications to build molecular dynamics systems

Three open‐source applications, NanoEngineer‐1, packmol, and mis2lmp are integrated using an open‐source file format to quickly create molecular dynamics (MD) cells for simulation. The three software applications collectively make up the open‐source software (OSS) suite known as MD Studio (MDS). The software is validated through software engineering practices and is verified through simulation of the diglycidyl ether of bisphenol‐a and isophorone diamine (DGEBA/IPD) system. Multiple simulations are run using the MDS software to create MD cells, and the data generated are used to calculate density, bulk modulus, and glass transition temperature of the DGEBA/IPD system. Simulation results compare well with published experimental and numerical results. The MDS software prototype confirms that OSS applications can be analyzed against real‐world research requirements and integrated to create a new capability. © 2014 Wiley Periodicals, Inc.