云进化机器人路径规划算法

针对EA(evolutionary algorithm)在机器人路径规划中局部收敛和收敛速度慢的缺点,结合云模型的优良特性,提出了基于云模型的路径规划算法.本算法采用正态云算子在路径池中进行进化和变异.进化过程中出现跨代精英路径时说明靠近了较优路径,就可以缩小进化范围,同时还利用了往次进化过程中的优化结果,来保证最终结果的准确性.仿真实验证明,本算法不但提升了进化速度,同时提高了路径的可靠性.     

采用奖惩规则格栅建模的机器人避障规划算法

针对传统的蚁群算法设计机器人避障路径规划,自适应能力差,全局优化能力和搜索速度不好的问题,在传统算法的基础上,提出一种采用奖惩规则格栅建模的机器人避障规划算法。提出构建模型主体的行为规则和避障规则,通过在栅格环境中设置量子遗传进化的多个有效的行为规则,设计了信息素更新的奖惩规则,修改其路径上的信息素,改变量子本身携带的信息素,得到优化避障最小距离。最终获得了复杂环境下的最优路径。仿真实验表明采用该算法进行机器人避障路径规划,在未知复杂环境下能够快速地规划出安全的优化路径,机器人避障路径规划具有很好的自适应性,相比传统的蚁群算法,其全局优化能力和搜索速度都得到了显著提高。     

基于多叉树Pareto最优解集的火灾扑救路径规划

提出一种基于多叉树Pareto最优解集的火灾扑救路径规划算法,对火灾现场的环境地图和火灾演化态势进行重构,实现对路径的优选,采用Pareto最优解集,构建基于多叉树Pareto最优解集的火源动态发展态势下的火灾扑救路径规划模型。实验结果表明,该模型能快速实现对火源热点的识别,并且规划路径能有效规避复杂建筑障碍物的干扰,实现对火灾扑救路径的最优选择。在动态未知环境中,对火灾扑救路径的规划和选择能达到最优,路径最短,分段较少,能有效地避免复杂建筑物的阻挡,有效节省了火灾扑救时间。     

传感节点优化覆盖机器人SLAM算法模型及仿真

为准确有效实现对移动机器人的同时定位和环境创建,在标准粒子滤波SLAM算法的基础上,对其进行算法上的改进,提出基于传感节点优化覆盖的SLAM算法,新的算法克服标准粒子滤波SLAM算法在机器人位姿同时定位和环境地图创建上的不准的缺点,进行传感节点优化覆盖机器人SLAM定位信息节点高覆盖度构建,改进的粒子滤波SLAM算法实现对现有信息下搜索到理想结果,在这个理想结果的基础上再次进行局部寻优,得到另一个局部状态下的理想结果,如此循环往复,最终得到全局准确的机器人SLAM信息。仿真实验表明,在不同的运动速度下计算机器人SLAM同时定位的时延参数的影响几乎为0,显示了新算法优越的定位稳定性能。     

基于声音的分布式多机器人相对定位

当同一环境中存在多个机器人时,很容易发生碰撞问题。为了避免该问题出现,需要对机器人的所在位置进行准确定位。在实际的定位过程中,有效的定位方法主要包含全局定位和相对定位两种。本文从声源定位的概念入手,对基于声音的分布式多机器人相对定位进行研究。     

多机器人协同控制验证平台定位系统设计

随着多机器人领域研究的不断深入,多机器人系统在军事、航空航天、营救搜索、自动化生产等领域得到广泛的应用,多机器人间的协同控制是多机器人系统中的核心问题之一。本文比较了目前各定位技术的特点,针对多机器人协同控制验证平台定位系统,利用UWB技术传输速率大、抗干扰能力强、抗多路径效应好的特点,构建定位系统,采用先测得距离数据,后由计算机计算出定位坐标的方法实现对机器人的实时定位。     

多信息融合迭代恢复匹配的访问路径偏移修正

在CStor云数据库访问中,细粒度云存储数据的信息特征存在个体较大差异,访问路径产生多频偏移,数据访问调度性能受限。传统方法中采用PSO局部搜索方法进行访问路径修正,搜索效率低,个体更新较慢。提出一种基于细粒度云存储数据迭代恢复匹配的云数据库访问路径偏移修正算法,以PSO多信息融合Pareto支配集为指导,构建多信息融合细粒度数据的主特征模型,采用迭代恢复匹配方法增加了局部搜索提高搜索到全局最优解的几率,实现路径偏移修正。仿真实验采用3组测试集对CStor云数据库进行访问调度和路径偏移修正,结果表明采用该算法,实现对访问路径的动态实时修正,收敛距离较小,提高了CStor云数据库访问和数据挖掘性能。     

基于Arduino的仿生虫型机器人系统研究

文章给出一种基于Arduino的仿生虫型机器人系统设计方案。在方案中,通过驱动控制子系统,实现了虫型机器人的仿生移动功能,同时通过测距子系统,实现了机器人避障功能。文中主要就这两个功能进行了详细的描述并对其实现过程进行了描述。     

六自由度并联机器人实时控制实现

并联机器人是一种新型机器人的机构，它与串联机器人相比，具有刚度大、精度高、负载重和易控制等优点。本文根据并联6-SPS机器人的位置和速度算法分析及运动特性分析算出的数据，给出了其硬件连接和软件实现的方法，在实现过程中解决了主机与从机之间的通讯与定时问题。并成功地用于机器人的控制中。得到了理想的控制效果。     

蚁群算法优化和路径规划问题的应用研究

基于智能仿生计算的蚁群优化算法在路径规划问题中具有较好的应用前景,通过蚁群算法优化,实现机器人路径规划和应急救援的路径规划等。传统的基于蚁群算法的路径规划在信息素转换中容易导致信息丢失,产生局部收敛,提出一种基于信息素多目标Pareto支配的蚁群优化算法实现路径规划,利用信息素多目标Pareto集合序列的均匀遍历特性和逻辑差分变尺度特征,进行变尺度搜索,根据蚁群优化算法一次次地更新搜索空间,结合负反馈机制,通过蚂蚁的信息素转化进行路径分析,采用Pareto支配集记录下最优的食物源,蚁群在寻找食物过程中,避免了局部寻优和局部收敛,仿真结果表明,采用该算法进行蚁群优化后的路径规划避障效果较好,以较快的收敛速度和较少的迭代次数找到最优路径,收敛性好。     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

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.     

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.     

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."     

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.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

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.     

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.     

The Information Environment and Universal Service

This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment.     

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.