基于模式的并行程序设计方法的研究现状

并行程序设计是并行计算的难点之一,基于模式的并行程序设计方法为程序员提供了并行程序的框架,比使用并行库(PVM和MPI)具有更高的抽象程度和通用性。本文简单地介绍了目前国际上三种应用此方法所开发的模型或项目以及我们所研究的SRVRT模型,并做出了比较。     

基于三维虚拟现实技术对周施雄双杠后上转体450°成倒立动作的分析

在世界上,中国运动员周施雄首次完成双杠后上转体450°成倒立动作。本文应用三维录像解析法对周施雄在比赛现场所做的后上转体450°成倒立动作采集运动学数据,利用沉浸式三维虚拟现实技术对获得的运动学数据进行重建,通过360°的旋转再现观察,以三维动画的形式进行运动学分析。研究发现周施雄在比赛中虽然完成了这一动作,但还有待完善。主要问题有上摆阶段伸髋较早、幅度稍大,导致在下一阶段的转体过程中单臂支撑的时候人体重心离支撑点的水平距离偏大,身体产生了倾斜,影响了之后的倒立动作,另外在转体阶段两腿并未完全并拢。     

知识管理自学习案例平行结构体方面相似度模型

为建立知识管理系统的自学习与自组织机制,本文将基于案例推理的技术思想引入知识管理自学习子系统,对知识管理自学习案例的平行结构体方面相似度进行系统而深入地研究。首先,论文对相关文献进行述评,阐明了本文研究的出发点,诠释了知识管理自学习案例平行结构体方面的内涵及其特征;继而,分七种情况深入讨论了平行结构体方面维度相似度的计算方法,并在此基础上提出了方面相似度的计算策略;最后,通过算例分析了相关技术策略与实施细节。     

Automatic extraction of bilingual word pairs using inductive chain learning in various languages

In this paper, we propose a new learning method for extracting bilingual word pairs from parallel corpora in various languages. In cross-language information retrieval, the system must deal with various languages. Therefore, automatic extraction of bilingual word pairs from parallel corpora with various languages is important. However, previous works based on statistical methods are insufficient because of the sparse data problem. Our learning method automatically acquires rules, which are effective to solve the sparse data problem, only from parallel corpora without any prior preparation of a bilingual resource (e.g., a bilingual dictionary, a machine translation system). We call this learning method Inductive Chain Learning (ICL). Moreover, the system using ICL can extract bilingual word pairs even from bilingual sentence pairs for which the grammatical structures of the source language differ from the grammatical structures of the target language because the acquired rules have the information to cope with the different word orders of source language and target language in local parts of bilingual sentence pairs. Evaluation experiments demonstrated that the recalls of systems based on several statistical approaches were improved through the use of ICL.     

“二董”《合刻栘华馆骈体文》艺术成就探论——兼论“二董”骈文的风格渊源与文学史地位

清代常州府是有清一代江南骈文重镇,而董基诚、董祐诚就是其中两位成就斐然的名家。由董基诚刊刻于道光十四年的《合刻栘华馆骈体文》4卷,是＂二董＂骈文创作成就的集中体现。研究发现,＂二董＂骈文写景清隽、抒情沉郁、议论精卓,取得了很高的艺术成就。在风格上,其远承汉魏六朝,近习洪亮吉、刘嗣绾等常州骈体名家,而且承中有创,自成一种＂儁不害窕,缛而有则＂或说＂绮隽＂之风格。就文学史地位而言,＂二董＂在同时可与方履篯颉颃并驾,而上可追洪亮吉、孙星衍、刘嗣绾,称得上是常州骈文名家,在清代骈文史上,也是不可多得的骈林双子星。     

单板滑雪平行大回转运动员身体训练的理论分析

单板滑雪平行大回转项目是我国新兴的雪上运动项目。单板滑雪平行大回转是受季节因素限制的冬季运动项目。身体训练对于单板滑雪平行大回转项目有着很重要的影响。身体训练可以为运动员完成基础训练做好身体准备,同时,也为专项的训练作好必要的体能储备。同时,由于受到季节的限制,不可能全年进行专项滑雪训练。在非雪期就要安排很好的身体训练用来保持和提高运动员的体能,为运动员的专项雪上训练做好充分的准备。     

Performance-oriented parallel distributed compensation

The main idea of the original parallel distributed compensation (PDC) method is to partition the dynamics of a nonlinear system into a number of linear subsystems, design a number of state feedback gains for each linear subsystem, and finally generate the overall state feedback gain by fuzzy blending of such gains. A new modification to the original PDC method is proposed here, so that, besides the stability issue, the closed-loop performance of the system can be considered at the design stage. For this purpose, the state feedback gains are not considered constant through the linearized subsystems, rather, based on some prescribed performance criteria, several feedback gains are associated to every subsystem, and the final gain for every subsystem is obtained by fuzzy blending of such gains. The advantage is that, for example, a faster response can be obtained, for a given bound on the control input. Asymptotic stability of the closed loop system is also guaranteed by using the Lyapunov method. To illustrate the effectiveness of the new method, control of a flexible joint robot (FJR) is investigated and superiority of the designed controller over other existing methods is demonstrated.     

封面设计中基本构图要素的传统美学观照

基本构图要素是与符号不同且更为基本的封面视觉传达要素,对于读者的封面阅读审美过程具有重要作用。封面阅读的审美过程与读者的文化传统有着深厚的关联,创作者在进行封面设计时必须考虑中国读者的独特审美倾向:欣赏"平衡"之美,追求"中和"之美,偏爱"飞动"之美,崇尚"清新"之美。     

Optimum calibration of a parallel kinematic manipulator using digital indicators

This paper presents a calibration method for parallel manipulators using a measurement system specially installed on an external fixed frame. The external fixed frame is important as an error reference for calibration in certain operations, such as in the configuration of a parallel manip- ulator functioning as a machine tool where the workpiece is fixed to a worktable. The pose of the end-effector is mea- sured using three digital indicators installed on the external fixed frame. To enable measurement, the end-effector is assumed to be a plane large enough that all digital indicators could touch. The error is defined as the difference between the theoretical and actual readings of the digital indicators. The geometric parameters of the parallel manipulator are optimized to minimize this error. This calibration method is low cost and feasible for compensating geometric parameter errors for a parallel manipulator. Optimal pose selection for the calibration is achieved using a swarm intelligence search algorithm. The method is implemented on a prototype of a six degrees-of-freedom （DOFs） Gough-Stewart platform constructed to function as a machine tool.     

云计算研究和发展综述

云计算是在分布式处理、并行处理和网格计算的基础上发展的一种新型计算模型,它使计算分布在大量的分布式计算机上,而非本地计算机或远程服务器中,提供了可靠安全的数据存储、方便快捷的互联网服务和强大高效的计算能力。对世界各地区高校在云计算领域上的研究及发展动向进行了论述。