Optimal control of multisolution ordinary differential equations in the absence of convexity

<正> In this paper,the authors study an optimal control problem governed by a class of multistateordinary differential equations in the absence of convexity.To overcome the difficulty that thecorresponding approximate optimal control problem may have no solution,relaxed controls are introduced.With the help of relaxation theory,Pontryagin's maximum principle for the optimal pairs ofthe original control problem is obtained.In the end of this paper,the authors discuss the applicationof the maximum principle by an example.     

On functional decomposition of multivariate polynomials with differentiation and homogenization

This paper gives a theoretical analysis for the algorithms to compute functional decomposition for multivariate polynomials based on differentiation and homogenization which were proposed by Ye,Dai,and Lam(1999) and were developed by Faugere,Perret(2006,2008,2009).The authors show that a degree proper functional decomposition for a set of randomly decomposable quartic homogenous polynomials can be computed using the algorithm with high probability.This solves a conjecture proposed by Ye,Dai,and Lam(1999).The authors also propose a conjecture which asserts that the decomposition for a set of polynomials can be computed from that of its homogenization and show that the conjecture is valid with high probability for quartic polynomials.Finally,the authors prove that the right decomposition factors for a set of polynomials can be computed from its right decomposition factor space.     

Conceptual design and RCS performance research of shipborne early warning aircraft

In order to improve the survivability of the aircraft,conceptual design and radar cross section（RCS） performance research are done. The CATIA software is used to design the 3D digital model of the shipborne early warning aircraft, and some measures are taken to reduce the RCS characteristics of the early warning aircraft at the same time. Based on the physical optics method and the equivalent electromagnetic flow method,the aircraft＇s RCS characteristics and strength distribution characteristics are simulated numerically, and compared with the foreign advanced shipborne early warning aircraft. The simulation results show that under the X radar band, when the incident wave pitching angle is 0？, compared with the foreign advanced shipborne early warning aircraft, the forward RCS average value of the conceptual shipborne early warning aircraft is reduced to 24.49%, the lateral RCS average value is reduced to 5.04%, and the backward RCS average value is reduced to 39.26%. The research results of this paper are expected to provide theoretical basis and technical support for the conceptual design and the stealth design of the shipborne early warning aircraft.     

A bright example for all of us- Professor Shi Changxu

Professor Shi Chanxu received the Top Scientists Award of China in early 2011.This is a very important event.As a materials scientist originally from China,I am very happy to hear this news.I see this award as a great encouragement,not only for people working in the field of Materials Science and Engineering, but also for all scientists and technologists in China. Professor Shi is one of the most famous materials scientists in the world,and has also made great contributions to the strategic development of science and engineering in China.I had the opportunity to listen     

公路建设项目合同管理现状及对策措施

根据目前公路建设合同管理的现状,作者在分析公路建设合同管理工作中的不足及成因的基础上,提出了加强公路建设合同管理的对策和措施.     

配电网节能降损研究

文章介绍了电网电能损耗,即线损的概念,以及其重要性和对电力企业经济的影响,总结出管理与技术上的经验,为节能降损的研究提出了建议.     

临终关怀:让每个临终病人尊严地走完一生

以人为本，以病人为中心，是医院为患者服务的宗旨。随着医院医德医风的建设．医护人员对濒临死亡病人的护理日益受到重视。让每个病人都能尊严无憾地走完自己的最后历程，是当今医院和社区医疗服务建设的重要内容之一。     

论桥梁抗震模型建立分析的目的

文章论述了桥梁抗震评估的建立模型和分析手段,其目的是用结构位移、构件受力及变形对桥梁地震反应进行定量化分析。     

关于独立避雷针保护内边界问题的探讨

文章对避雷针的保护原理进行了简单介绍,同时根据直击雷引发的反击现象提出了独立避雷针的保护范围问题,强调独立避雷针的保护范围除了外边界之外,还应该有根据防止雷电反击的安全距离确定的保护内边界,强调独立避雷针必须正确安装,合理使用,才能真正实现其保护价值。     

浅谈热力管网工程施工工艺与质量控制

热力管网工程的施工工艺复杂,而且每一道工艺都非常严格.所以在施工过程中须严格规范规定的施工工艺操作.