解结构动力问题的半隐式Runge-Kutta型并行直接积分法

本文利用三级三阶半隐式Runge-Kutta法解结构动力问题,并用多项式预处理共轭梯度法解有关方程组。提出了半隐式Runge-Kutta型并行直接积分法RK33P。在YH-1机上,与相应的串行算法RK33S相比较,当有关方程组的阶数为10³~10⁴时,加速比可达24~27。     

适用于Linux系统的高效可并行电磁PIC计算技术

为了能够使大型机和高性能集群得到更好的加速比和并行计算效率,在深入研究并行和FDTD-PIC算法的基础上,在CHIPIC软件平台上开发了Linux系统下的大型全三维可并行电磁PIC代码。分别以一个磁绝缘线振荡器、回旋管和相对论速调管为例进行测试和计算,得到了3.70,6.72和6.00的加速比,验证了在同等的进程数下,高性能集群能够得到比PC机群高得多的加速比和计算效率,能够更好地利用计算资源。     

适用于Linux系统的高效可并行电磁PIC计算技术

为了能够使大型机和高性能集群得到更好的加速比和并行计算效率,在深入研究并行和FDTD-PIC算法的基础上,在CHIPIC软件平台上开发了Linux系统下的大型全三维可并行电磁PIC代码。分别以一个磁绝缘线振荡器、回旋管和相对论速调管为例进行测试和计算,得到了3.70,6.72和6.00的加速比,验证了在同等的进程数下,高性能集群能够得到比PC机群高得多的加速比和计算效率,能够更好地利用计算资源。     

单通道分光测色仪的数据采集技术

介绍了一种利用光电倍增管作为探测器的光栅扫描式单通道分光测色仪的单片机电路设计和利用C语言程序直接对串口芯片的寄存器进行读取操作的数据采集技术。给出了仪器中的下位机(8051单片机)和上位机(PC机)的软件设计思想。实验测得的结果证实了该仪器具有很高的测量精度。     

电子倍增CCD的电荷倍增特性研究

建立了电子倍增CCD的载流子倍增寄存器的电荷倍增模型,分析了电子倍增CCD的结构特征和载流子倍增寄存器的工作原理及其电荷倍增特性.利用Z域分析方法得到载流子倍增寄存器的电荷倍增传递函数及其幅频响应.计算表明,提高载流子倍增寄存器的电荷倍增系数可以提高电子倍增CCD的幅频响应.同时,用增益起伏因子来分析载流子倍增寄存器的增益起伏特性,得到了电荷倍增率,寄存器级数与增益起伏因子的数值关系.在寄存器级数N=400条件下,当电荷倍增系数α≤0.15时,增益起伏因子随电荷倍增系数增大而增大;而当α≥0.15时,增益起伏因子随电荷倍增系数的增大而减小.通过典型的电子倍增CCD相机的实验验证了建立的模型.     

测距机与数字单冲电路

本文介绍一种装有数字单冲电路的改进型测距系统,该系统采用最新应答测距系统(美国专利№3545861)记数技术。本发明的改进型数字单冲电路装有一个N比特移位寄存器和一个D型触发器。移位寄存器有一个时钟接头和一个数据接头,它们分别由钟脉冲信号和表示逻辑1的固定电压触发,     

新的summing算法的核磁共振实验实现

本文报导了一种新的summing算法的核磁共振实验实现.实验中我们用到了四个量子位的核自旋体系,其中两个量子位构成输入寄存器,另两个量子位构成输出寄存器.最后的实验结果只需通过测量输出寄存器中核自旋的谱线获得.     

基于GPU求解椭圆型偏微分方程的并行算法

针对求解椭圆型偏微分方程的雅克比迭代算法和DRM算法进行基于GPU的CUDA加速算法研究.通过两个算例在GTX570显卡上对GPU加速算法进行验证.结果表明,在保证运算精度的前提下,雅克比迭代的GPU加速效率最高,在DOUBLE类型下的加速比可达到14倍左右,效率可达到53%左右;DRM算法在DOUBLE类型下的加速比最高可达到3.8倍,效率达到15%左右.     

S波段2MeV轴耦合驻波加速管参数冷测调试

介绍了用于工业CT的S波段2MeV驻波电子直线加速管的微波冷测及调整,并详细描述了加速管频率的测量与调谐,加速管与矩形波导匹配,加速管品质因数及加速管整管场分布的测量,给出了加速管微波调试及调整的结果.结果如下:加速管的频率一致性达到±0.3MHz以内,过饱和状态下的耦合度为1.14,加速管单腔的品质因数约为120004-200,场分布的比值1:2.2:2.结果表明微波调试满足物理设计的要求.     

S波段2MeV轴耦合驻波加速管参数冷测调试

介绍了用于工业CT的S波段2MeV驻波电子直线加速管的微波冷测及调整, 并详细描述了加速管频率的测量与调谐, 加速管与矩形波导匹配, 加速管品质因数及加速管整管场分布的测量, 给出了加速管微波调试及调整的结果. 结果如下: 加速管的频率一致性达到±0.3MHz以内, 过饱和状态下的耦合度为1.14, 加速管单腔的品质因数约为12000±200, 场分布的比值1:2.2:2. 结果表明微波调试满足物理设计的要求.     

快速傅里叶变换的并行计算

本文是"快速傅里叶变换向量化程序包"研制工作的部分内容,主要介绍一维、二维复数据快速傅里叶变換的并行计算方法及其计算效率。在银河机(YH—1)上的计算实践表明,向量运算比相应的标量运算,平均可提高功效数十倍。     

一类流体力学问题的并行计算

概述了二维流体力学程序YGX等在银河-1和银河-2巨型计算机上的向量化和并行化工作,总结了一些具有一般意义的实际经验,给出了程序在计算机上执行所获得的重要测试数据。     

A new multispin coding algorithm for Monte Carlo simulation of the Ising model

We present a new algorithm for Monte Carlo simulation of the Ising model. The usual serial architecture of a computer is exploited in a novel way, enabling parallel but independent calculations to be carried out on as many spins as there are bits in a computer word in each fundamental move. The algorithm enjoys a substantial increase in execution speed over more usual multispin coding algorithms. By its very nature, the algorithm constitutes a design for a special-purpose processor.     

Mathematical analysis of coupled parallel simulations

A set of parallel replicas of a single simulation can be statistically coupled to closely approximate long trajectories. In many cases, this produces nearly linear speedup over a single simulation ( M times faster with M simulations), rendering previously intractable problems within reach of large computer clusters. Interestingly, by varying the coupling of the parallel simulations, it is possible in some systems to obtain greater than linear speedup. The methods are generalizable to any search algorithm with long residence times in intermediate states.     

Order statistics on optically interconnected multiprocessor systems

Processor arrays with an optical bus are introduced for parallel computation in this paper. We use the order statistics problem as an example to demonstrate how to design efficient parallel algorithms on such systems. Besides proposing a new algorithm on the model, some basic data movement operations involved in the algorithm are discussed. We believe that these operations can be used to design other parallel algorithms on the same model. Time analysis indicates that order statistics can be done more efficiently on a linear array with a pipelined optical bus than with an electronic bus. The initial results are promising, and the author believes that optical buses may emerge as a powerful communication mechanism for connecting large parallel computer systems in the near future.     

基于Tahoe框架的某夹具并行计算

在开源软件Tahoe框架基础上,结合有限元前后处理程序MSC.Patran及Tecplot,对某复杂夹具进行建模.通过区域分解、编制接口和采用PHG中提供的PCG(preconditioned conjugate gradient,预处理共轭梯度法)迭代解法成功实现262×10⁴自由度模型的串、并行计算.结果表明,并行计算收敛速度更快,4进程并行计算时间不到串行计算时间的1/4.通过与商用程序MSC.Nastran比较,验证计算结果的正确性.利用大型并行计算机对该模型并行计算性能进行研究,获得最高32进程的并行计算加速比.研究表明,改进后的Tahoe计算框架对于开展大规模自由度下的结构并行计算分析研究是可行的,并且随计算节点增加,并行计算过程基本呈线性加速.     

Parallel computing for fringe pattern processing: A multicore CPU approach in MATLAB environment

In the process of measurements such as optical interferometry and fringe projection, an important stage is fringe pattern analysis. Many advanced fringe analysis algorithms have been proposed including regularized phase tracking (RPT), partial differential equation based methods, wavelet transform, Wigner–Ville distribution, and windowed Fourier transform. However, most of those algorithms are computationally expensive. MATLAB^® is a general algorithm development environment with powerful image processing and other supporting toolboxes. It is also commonly used in photomechanical data analysis. With rapid development of multicore CPU technique, using multicore computer and MATLAB^® is an intuitive and simple way to speed up the algorithms for fringe pattern analysis. The paper introduces two acceleration approaches for fringe pattern processing. The first approach is task parallelism using multicore computer and MATLAB^® parallel computing toolbox. Since some algorithms are embarrassing problems, our first approach makes use of this characteristic to parallelize these algorithms. For this approach, parallelized windowed Fourier filtering (WFF) algorithm serves as an example to show how parallel computing toolbox accelerates the algorithm. Second, data parallelism using multicore computer and MATLAB^® parallel computing toolbox is proposed. A high level parallel wrapping structure is designed, which can be used for speeding up any local processing algorithms. WFF, windowed Fourier ridges (WFR), and median filter are used as examples to illustrate the speedup. At last, the results show that the parallel versions of former sequential algorithm with simple modifications achieve the speedup up to 6.6 times.     

强光电离团簇并行数值模拟

 为研究强激光电离氢原子团簇,在理论上采用1维氢原子团簇的经典粒子动力学模型,结合粒子对(PP)算法及粒子模拟（PIC）方法,采用自行搭建的9节点并行集群系统,利用消息传递接口（MPI)与OpenMP混合编程模型进行了并行数值模拟计算,获得了较为理想的计算加速比。并且引入了弛豫时间参数,有效地处理了粒子间的碰撞过程,在极大简化计算量的同时,保留了物理本质。所得模拟结果与已有的实验结果符合较好,表明该并行计算模型是稳定、可行的。     

Fully parallel algorithm for simulating dispersion-managed wavelength-division-multiplexed optical fiber systems

An efficient numerical algorithm is presented for massively parallel simulations of dispersion-managed wavelength-division-multiplexed optical fiber systems. The algorithm is based on a weak nonlinearity approximation and independent parallel calculations of fast Fourier transforms on multiple central processor units (CPUs). The algorithm allows one to implement numerical simulations M/2 times faster than a direct numerical simulation by a split-step method, where M is a number of CPUs in a parallel network.