Independent force and position control for cooperating manipulators

The problem of independent force and position control of multitask cooperating manipulators is studied. Each manipulator is in a non-singular configuration and the object can be driven by the contact forces exerted by the end effectors of the manipulators. The design requirement is to control each coordinate of the position of the object as well as each component of the “rest” forces, except the moving forces that are determined uniquely from the object's position. The present design requirement has been proved to be always satisfied together with asymptotic and BIBO stability. A class of controllers solving the above simultaneous problem is analytically determined. The proposed state feedback controller does not depend upon the specific object dynamics and thus the resulting closed-loop multimanipulator system performs as required, not only when handling various objects but also when the dynamics of the objects are unknown or hard to compute or disturbed by external forces.     

传热强化课程双语教材建设

针对过程装备与控制工程专业的特点,对传热强化技术选修课程进行了双语教材建设。教材内容采取理论、技术、专题的三模块方式编排,结合课程特点和专业特点,进行了参考教材的选择,给出了教材的具体内容架构,并指明了教材的特色。     

规范与现实之间:道路交通管制制度检视

交通管制作为《道路交通安全法》规定的一种严肃的交通行政行为,其概念被广泛误读;分析该法第39条、第40条和《人民警察法》第15条之规定,有助于对交通管制概念的正确理解;交通管制制度实践运作中的三种乱象背离了法律规定并带来了诸多消极后果。这些表明:交通管制原始概念亟待回归,行政理念尚需更新,行政执法的法律依据适用错误,地方性法规规定违反上位法,交通管制制度的规则有待完善。     

明清时期九溪卫地区民族教育发展刍议

洪武前期,朝廷在湘西地区设置九溪卫军民指挥司,推行"以夷制夷"的政策,实行文化控制,设立卫学、县学、义学、书院。教育的发展推动了九溪卫子弟向学之风的形成,促进了九溪卫地区文化的发展和繁荣,为国家培养了一批人才,加强了中央王朝对湘西的统治。     

西门子S7-300 PLC的水箱液位控制系统的仿真

本文对一个西门子S7-300 PLC控制水箱液位的系统进行了仿真。运用西门子PLC的相关软件"SIMATIC Manager"、"S7-PLCSIM"、"WinCC"来仿真整个水箱液位控制系统。最终在没有真实的PLC、电动调节阀、水箱等实际水箱液位控制系统硬件的情况下,只用一台安装有相关PLC软件的电脑仿真了整个PLC控制水箱液位的系统。这对缺乏硬件的学习者学习PLC是很有意义的。     

综合评价方法在防砂方式优选中的应用

为解决油田疏松砂岩油藏油井出砂问题,发展了多种防砂技术,然而每种防砂方式有各自的适应性及优缺点．针对目前油井防砂方法优选存在的问题和不足,拟采用模糊数学原理,初选技术上可行的防砂方法,然后利用经济评价模型给出经济有效的防砂方法,再结合两种方法的计算结果,进行综合评价,优选出技术上科学合理、经济高效的防砂方法．为油田防砂方法的选择提供决策依据．应用综合评价方法对两口井进行了计算分析,通过综合评价模型给出了适合该井的技术合理、经济有效的防砂方法;另外,当模糊数学评价模型与经济评价模型计算结果有差别时,要结合综合因素进行选择．     

水质监测中质量控制措施研究

质量控制和质量保证是分析工作的内容之一,是当前环境监测需要解决的技术关键和科学管理实验室的有效方法．水质监测质量控制是水质环境监测中的重要组成部分,在保证监测数据的代表性、准确性、精密性、可比性和完整性方面具有相当重要的作用．文章从介绍水质监测中质量控制的目的、意义出发,阐述水质监测的主要内容,并提出水质监测质量控制的措施和建议．     

Development of self-belief for employability in higher education: ability,efficacy and control in context

Self-belief is argued here to be a key aspect of employability development that has been largely under conceptualisation in terms of what the construct may mean and how it may be developed through higher education (HE) study. This paper proposes three fundamental beliefs that need to be fostered in order to develop student self-belief: (1) that ability can be improved; (2) that one has the ability to achieve one's goals; and (3) that the environment will allow for goal attainment. Self-belief needs to be developed within the HE curriculum in the context of disciplinary knowledge and skills. The factors that may influence the development of these beliefs within the curriculum will be explored along with implications for practice that may support the development of self-belief and contribute to the production of employable graduates from HE.     

Farmers' Adoption of Soil Conservation Technologies: A Case Study from Osun State,Nigeria

Abstract

The main objective of this study was to determine the attitude of farmers towards erosion and the adoption of appropriate soil conservation technologies (SCTs). For the survey, farmers were selected from the communities Esa Oke, Elwure and Owode-Ede and Akoda in Osun State in Nigeria. In the first three communities farmers did receive training on soil conservation, in the fourth not. About 60 farmers were interviewed to obtain information on personal and socio-economic characteristics, awareness of environmental problems, attitude towards erosion control and experiences with SCTs. Statistical data analyses (analyses of frequencies, correlation, t-test, χ²-test) were made to examine possible relationships among parameters and the influence of factors on adoption.

Most respondents were advanced in years, responsible for large households and characterized by low levels of income and literacy. Soil erosion was seen as a problem confronting agricultural production only to a small extent. The adoption rate of SCTs was low, as only mulching, cover cropping, contour tillage and cut-off drainage were practised and often rejected. Low labour-demand, the availability of common equipment, low costs of application, ease of practice and compatibility with the existing farming system influenced adoption.

The observed positive correlation between level of education, knowledge of appropriate technologies, farming experience and the number of SCTs adopted emphasizes the importance for farmers of education and training. Strengthening agricultural extension agencies for capacity building is an important tool for improving soil conservation in Nigeria.

The paper clarifies with specific examples the causes of the low rates of adoption of available technologies, with a reduced impact of research and of efforts to achieve food security and sustainable production at village level.     

论紧张对音乐表演的积极作用

音乐表演过程中,表演能力的呈现和展示受到表演者心理因素的影响和调控,因此,心理因素应该得到关注.紧张作为普遍的心理现象,在音乐表演中广泛存在.文章在分析紧张状态的心理学定义、表演者在音乐表演中紧张状态表现的基础上,研究了心理控制对音乐表演的积极作用,提出了如何利用心理控制的积极作用,从而获得音乐表演良好效果的措施.