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991.
针对Image Quilting纹理合成算法的新旧纹理块拼接特点,研究了一种创建多任务实现纹理块切割拼接的并行编程模式.设计了重叠区域缝合路径计算的多任务模块函数iq(),利用MATLAB多核集群中创建的调度器将子任务分配到各个节点上并行执行计算.实验结果表明,该算法获得了较好的加速比,提高了多核CPU的使用效率,有效地提升了多核计算机资源的利用率. 相似文献
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应用多重网格区域分裂并行计算方法研究具有壁面Weis-Fogh机构绕流,将二维物理平面流动区域变换为矩形区域,推导出流函数的多重网格差分计算格式,编制出并行计算程序。全部计算在英国London大学ITL并行计算中心完成。结果表明,多重网格并行计算具有较高的加速比,绕机翼的环量计算值与理论吻合。 相似文献
995.
针对电力系统暂态监测数据向海量化发展的趋势,以及对各种串行编程分析软件造成的计算压力,研究了一种基于多核的、采用流水线设计思想的海量电力系统暂态数据交换通用格式(COMTRADE)数据文件并行解析算法。在面向二进制格式的并行解析算法中,采用了2阶段的流水线步骤:第1阶段为文件读取;第2阶段为多线程解析。在面向美国标准信息交换码(ASCII)格式的并行解析算法中,采用了3阶段的流水线步骤:前2个阶段与二进制格式的并行解析算法一样,第3阶段为块边缘解析,打破了传统的串行文本解析算法。算法通过有效利用以往被忽视的数据文件中的序号信息,大幅提升了并行解析的并行度。试验证明此算法可获得相当高的加速比,并且可随着CPU核数的增加和COMTRADE数据文件的加大获得线性加速比。 相似文献
996.
This article discusses the production and ordering policies in a supply chain consisting of a single manufacturer and a single retailer. The retailer places orders based on the EOQ-like policy, and the manufacturer purchases raw materials and allocates them to the multiple plants in parallel to produce demand requirement from the retailer. The model is mathematically formulated, and the solution procedure is developed to determine the production cycle length, ordering quantity and frequency, and production allocation ratios for multiple plants. The closed forms of the production cycle length, ordering quantity, and frequency in terms of the production allocation ratios are obtained. It is also shown that the production allocation problem is NP-hard. An efficient and effective heuristic algorithm is proposed to determine the near-optimal production allocation ratios. A numerical experiment demonstrates that the proposed algorithm performs quite satisfactorily. 相似文献
997.
The increase in computational capabilities has made time-domain methods applicable for long-range sound propagation modelling. However, such approaches remain very demanding in terms of computational resources. Most current computers are supplied with a powerful device which is still little exploited: the graphics processing unit (GPU). The paper describes an implementation of a transmission line matrix model which allows parallel calculations on heterogeneous systems. A voxelization algorithm used to generate the computational domain is presented. A splitting process is also expounded which makes feasible performing huge domains simulations by accurately dividing the computational domain into subdomains. Each subdomain is enlarged by introducing extra cells containing neighbours subdomains data in order to run several computational iterations on a graphic device without data exchange with the system memory. The influence of the ghost layer depth and the speeding up of computation time with GPU are then illustrated in a realistic built-up area. 相似文献
998.
Following several recent papers discussing various problems of scheduling a maintenance activity, we focus here on scheduling a maintenance activity on unrelated parallel machines. The objective is to minimize flow-time. In the basic setting, we assume that all the machines must be maintained simultaneously. The problem is known to be NP-hard, and we introduce and test numerically an efficient heuristic and a lower bound, both based on a solution of a matching problem. We also study the relaxed version, where the machines are not restricted to be maintained at the same time. Similar heuristic and lower bound are proposed and tested. 相似文献
999.
数据库系统已成为当代计算机系统的重要组成部分.如何科学地组织和储存数据.如何有效的解决数据库中并发控制带来的死锁现象,就此提出了几个解决途径和遵循原则. 相似文献
1000.
Factor-analytic research is common in the study of constructs and measures in psychological assessment. Latent factors can represent traits as continuous underlying dimensions or as discrete categories. When examining the distributions of estimated scores on latent factors, one would expect unimodal distributions for dimensional data and bimodal or multimodal distributions for categorical data. Unfortunately, identifying modes is subjective, and the operationalization of counting local maxima has not performed very well. Rather than locating and counting modes, the authors propose performing parallel analyses of categorical and dimensional comparison data and calculating an index of the relative fit of these competing structural models. In an extensive Monte Carlo study, the authors replicated prior results for mode counting and found that trimming distributions' tails helped. However, parallel analyses of comparison data achieved much greater accuracy, improved base rate estimation, and afforded consistency checks with other taxometric procedures. Two additional studies apply this approach to empirical data either known to be categorical or presumed to be dimensional. Each study supports this new method for factor-analytic research on the latent structure of constructs and measures in psychological assessment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献