基于改进粒子群算法的机器人机构误差补偿

并联机器人最重要的性能标准是运动精度,而并联机器人在给定的预期轨迹规划过程中,往往因存在机构误差导致预期轨迹和理想轨迹存在很大偏差,导致运动精度大大降低。针对以上情况本文提出了一种基于粒子群算法,对机器人的驱动杆期望轨迹不断修正,进而补偿机器人机构误差;通过种群排列熵模型和粒子速度激活方法改进粒子群算法,利用改进后的粒子群算法对机器人驱动杆参数进行优化,对机器人结构误差补偿,进而不断修正机器人驱动杆的预期轨迹,补偿机器人轨迹规划过程中的运动误差。仿真结果表明:本文所提出的方法能够有效对机器人机构误差进行补偿,有效补偿了机器人轨迹规划中的运动误差,保证了机器人的运动精度。     

足球机器人智能控制系统分析与设计

本文基于多智能体系统（MABS）的分级递阶智能控制系统结构提出了足球机器人系统的分级递阶智能控制结构,并将该控制结构用于足球机器人智能控制系统,并运用基于智能控制的专家系统为足球机器人真正实观智能化控制提供了一种可行的控制方案。     

足球机器人视觉系统的颜色空间选择

颜色空间在足球机器人视觉系统的图像处理中起着决定性的作用,文中在分析常用的RGB、HUV和HSI三种颜色空间特点的基础上,通过实验对三种颜色空间在不同条件下进行分析比较,最终选取HSI作为足球机器人视觉系统的颜色空间,实验结果证明该颜色空间能够满足机器人足球比赛要求。     

基于全局视觉的足球机器人的视觉训练系统设计

机器人足球比赛是近年来在计算机和自动控制等领域内的一项非常有前景的研究课题,相当多的理论、算法和技巧被提出并实现。其中有关足球机器人的视觉系统的研究更是创新不断。本文设计了一个基于RoboCup小型组足球机器人的视觉训练系统模型,并对该模型的原理、模块组成和工作方式进行了分析。文中使用了一种基于阈值的颜色标定方法,可以通过训练和学习来动态的建立视觉关系模型,供视觉系统在比赛时使用,使视觉系统对环境具有较强的适应性。     

混合遗传进化机器人同时定位路径偏移纠正

机器人的同时定位与地图创建技术是实现机器人移动过程中自主定位和控制的关键技术,在机器人同时定位目标的过程中,常出现路径偏移,需要进行路径偏移纠正,实现精确控制。提出一种基于多叉树混合遗传进化的机器人同时定位路径偏移纠正控制方法,首先进行多叉树混合遗传进化机器人同时定位控制建模,在对多信息融合下进行机器人同时定位,得到基于多叉树混合遗传进化的机器人同时定位路径修正测试函数。仿真实验和研究结果表明,该算法可以实现机器人同时定位路径偏移纠正,对机器人的控制精度较高,以较快的收敛速度找到了最优路径,其全局优化能力和搜索速度都得到了显著提高。     

多足球机器人视觉躲避相撞算法的仿真分析

在机器人足球比赛中,比赛过程对抗性激烈,需要机器人在运动状态下完成障碍物的躲避,但是当前的多机器人时间配合任务中,对避障的要求往往都是单一的,静态的障碍物,对运动中的同视觉机器人壁障效果不好。为了解决这一问题,提出一种基于多传感器运动信息约束规划的机器人视觉避障技术,采取信号采样技术采集多路机器人信号,采用射线追踪算法和内建的相撞检测机制,对足球机器人实际的不同路状下进行障碍躲避。实验证明该方法具有很好的鲁棒性与有效性。     

基于灰色理论的分裂合并算法研究

为了分割出图像中感兴趣的区域,提出了一种基于灰色理论的分裂合并算法。该方法利用灰色关联理论对分裂的图像进行关联性分析,根据区域间综合关联度,指导区域是否合并。该方法的最大不同之处在利用灰色理论进行关联性分析,不需要大量数据的统计,算法简单,高效。实验证明,该方法能够有效地分割出目标区域,并且具有一定的抗噪能力,是一种较为有效的图像分割新方法。     

计及道路阻断的智能消防机器人路径规划策略

合理的运行路径规划对保障智能消防机器人的可靠运行意义重大。针对消防机器人路径规划问题,文章在对A-Star算法原理及动作过程进行深入分析的基础上,建立了适用于智能消防机器人的路径规划模型。之后,考虑到火灾现场存在的道路阻断问题,文章基于贪婪思想,提出了一种智能消防机器人路径修正策略。仿真结果表明,所提智能消防机器人路径规划与修正方案能够较好地解决火灾现场存在的道路阻断问题,有效提升消防机器人路径规划的合理性与可靠性。     

多波束粒子群深度零点轨迹信息搜索效率优化

传统的基于粒子群算法的前馈神经网络训练系统进行数据库访问时,易陷入局部极值,产生零点轨迹信息搜索效率较低,局部极小点和搜索方向紊乱。提出一种改进的粒子群优化算法。构建基于误差反传的神经网络系统结构,引入混沌映射概念,提出了一种根据粒子搜索状态,动态调整粒子飞行速度和位置的粒子群优化算法,提高多波束粒子群深度零点轨迹信息的提取的搜索效率,根据粒子的轨迹信息,研究如何动态调整粒子的搜索速度和方向,提高了训练和控制精度与效益。仿真实验表明,该算法进行多波束粒子零点轨迹信息搜索,效率较高,通过外力的干涉尝试调整粒子的方向,使得粒子可以逃离这个稳定阶段,提高了粒子收敛速度,提高控制搜索精度,运行时间较短。算法在智能控制等领域具有较好的应用价值。     

基于路由热点循迹修正的WSN发射功率优化调度

无线传感器网络WSN发射功率的优化调度是决定WSN使用寿命和提高WSN性能的关键,WSN路由节点的在进行数据转发时会导致热点随机扩散,发射功率无法难以实现最大化。提出一种基于路由热点循迹修正的WSN发射功率调度算法。设计了WSN节点路由热点循迹数据传输模型,对发射功率消耗能量模型采用一个高斯衰减信道建模,采用直线反馈线性化补偿方式对路由热点的偏移轨迹进行超负荷状态评估,采用贪婪算法生成一条多分簇路由链,对路由循迹轨迹进行修正,得到WSN优化发射功率的调度递推公式,实现能耗最佳的功率优化调度。实验结果表明,采用该优化调度方法,在准确实现热点循迹修正,传输功率较传统方法稳定,波动较小,WSN可靠性和生存性增强。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

To serve and promote science development via innovation

CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.     

Tracing the origin and early radiation of birds——Paleornithologist ZHOU Zhonghe

With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Our Own Devices: Heterotopic Communication, Discourse, and Culture in the Information Society 1

The main premise of this article is that in information societies generally, and in virtual social contexts particularly, a distinctive style of interaction to facilitate the communication of difference, heterotopic communication , has emerged. It rests on two cultural foundations: an ideological belief in the positive, socially integrating power of communication, and a prevailing ethic of instrumental rationality, subjective individualism, and strategically practiced self-interest. The former is demonstrated by the use of simulation and spectacle as sources of information; exhibitionism/voyeurism as a communicative style; and the awareness of surveillance. The latter is seen in the competitive use of knowledge as a commodity; a surface globalism masking deep parochialism; lateral as well as vertical information inequity; and the use of public versus private as strategies for engagement rather than as spaces. Those who engage in heterotopic communication resort to their 'own devices' both in the sense of personal agendas, strategies, interests, and interpretations, and in the form of the telecommunication tools that help realize them. These personal and technological devices allow individuals with the right educational and technical resources to avoid exposure to disagreement, difference, or other information that does not serve their direct purposes or reflect their particular views of the world; yet they also help convey the appearance of openness, availability, and cooperation. This style of interaction is used strategically in combination with information and communication technologies to gain social or economic advantages, but it may encourage social separatism and parochialism, inhibit the negotiation of disputes, and emphasize competing interests.