Robust block second order sliding mode control for a quadrotor

This paper presents the design of a controller based on the block control technique combined with the super twisting control algorithm for trajectory tracking of a quadrotor helicopter. A first order exact differentiator is used in order to estimate the virtual control inputs, which simplifies the control law design. In addition, the wind parameter resulting from the aerodynamic forces is also estimated in order to ensure robustness against these unmatched perturbations. The stability and finite time convergence of the exact differentiator have been recently proved by means of Lyapunov functions, and therefore the stability analysis of the proposed controller has been carried out along the same lines. The performance and effectiveness of the proposed controller are tested in a simulation study taking into account external disturbances.     

LCD控制器设计及uClinux移植

设计了一个用于液晶显示的LCD控制器,该控制器基于A1tera公司的SOPC系统,通过SOPC中的Avalon总线接口与NiosⅡ处理器和SDRAM控制器通信,完成对LCD的显示控制。并在该Nios Ⅱ系统上成功移植了uClinux。     

《光电子学中电磁场理论》研究生课程教学的思考

研究生课程教学是研究生培养的重要环节。搞好研究生专业基础课程建设,必须准确把握课程建设的目标和定位,合理设置研究生专业基础课程教学内容,并且注重在专业基础课程教学中培养研究生的创新思维和学术能力。     

中国杂技艺术中的体育文化解读

运用艺术史学、体育史学、考古学等学科原理,结合献资料,对中国杂技艺术中的体育化进行分析解读。结果显示：东西方两个明中心几乎同时开始了一个百家争鸣的时代,尽管各种身体活动的体育实践各不相同,但对于人体的速度、力量、健美、灵巧等基本身体素质的追求和赞美的理念,各民族几乎是共同的。古人在翻腾跳跃,窜蹦跌打的生存劳动技能中产生了“小武术”、“大武术”、“对手顶”,“走钢丝”、斗虎、耍狮子等活动形式,它们既是杂技也是体育项目。从古至今,中国杂技艺术与体育化共生共荣,和谐发展。     

School Organization and Persistent School Absenteeism: An Introduction to a Complex Problem

This article is concerned with the development of provision for pupils in a comprehensive school with special educational needs. Its main focus is on the organization and administration changes which were undertaken in connection with the recommendations of the Warnock Report, the 1981 Education Act and the development of knowledge and expertise within the school in helping such pupils.

It concentrates on five aspects: the communication of information about those pupils within the school, the curriculum available to them in the upper school, the deployment of staff, the name of the department to best fit its changing role in the school and the issues which need to be taken into account in monitoring those developments.     

Towards an American Jewish Education

My function is to analyze a survey of adult Jewish education and to present briefly some of my own views on the subject. The survey was planned and conducted under the direction of the National Advisory Council on Adult Jewish Education of the American Association for Jewish Education. The Advisory Council includes the directors or representatives of a number of important religious and lay national Jewish agencies which sponsor adult Jewish education. The responses to the questionnaires were analyzed and the Survey Report was written by Rabbi Samuel I. Cohen.