N中连续取k好可修系统的模糊可靠性

在假定关键部件具有较高的修理优先权的条件下,讨论了具有1个修理工的可修n中连续取k好系统.利用马尔可夫过程对系统的各状态进行分析,得出了系统各状态的概率.然后利用基于模糊状态的可靠性理论,通过定义系统各状态对模糊成功的隶属函数,得到了可修n中连续取k好系统的模糊可靠性指标的计算公式,并比较其结果与传统可靠性理论的不同之处.模糊可靠度可以反映系统中工作部件的数目对系统性能的影响,它全面刻画了系统的可靠性行为.最后给出了计算示例说明算法.     

Earth remote sensing as an effective tool for the development of advanced innovative educational technologies

Current educational system is facing a contradiction between the fundamentality of engineering education and the necessity of applied learning extension, which requires new methods of training to combine both academic and practical knowledge in balance. As a result there are a number of innovations being developed and implemented into the process of education aimed at optimizing the quality of the entire educational system. Among a wide range of innovative educational technologies there is an especially important subset of educational technologies which involve learning through hands-on scientific and technical projects. The purpose of this paper is to describe the implementation of educational technologies based on small satellites development as well as the usage of Earth remote sensing data acquired from these satellites. The increase in public attention to the education through Earth remote sensing is based on the concern that although there is a great progress in the development of new methods of Earth imagery and remote sensing data acquisition there is still a big question remaining open on practical applications of this kind of data. It is important to develop the new way of thinking for the new generation of people so they understand that they are the masters of their own planet and they are responsible for its state. They should desire and should be able to use a powerful set of tools based on modern and perspective Earth remote sensing. For example NASA sponsors “Classroom of the Future” project. The Universities Space Research Association in United States provides a mechanism through which US universities can cooperate effectively with one another, with the government, and with other organizations to further space science and technology, and to promote education in these areas. It also aims at understanding the Earth as a system and promoting the role of humankind in the destiny of their own planet. The Association has founded a Journal of Earth System Science Education. Authors describe an effective model of educational technology developed in the Center for Earth Remote Sensing of Bauman Moscow State Technical University and based on scientific and educational organizations integration in the field of applied studies. The paper also presents how students are being trained to acquire and process satellite imagery data from Terra and Aqua satellites. It also reveals the results of space monitoring for Russia's ecologically complex regions conducted by Bauman Moscow State Technical University students in cooperation with specialists from the Laboratory for Aerospace Methods of Moscow State University named after M. Lomonosov.     

航空航天复合材料绿色化发展浅析

简述了航空航天复合材料绿色化技术的研究进展,包括复合材料的绿色化设计、绿色材料、绿色制造,以及回收再利用等技术,探讨了复合材料绿色化技术的发展前景。     

太阳能无人机关键技术分析

介绍了当前太阳能无人机的发展现状,主要分析了太阳能无人机在设计、制造过程中所涉及到的各种关键技术,指出了需要突破的技术难点,包括轻质、高效太阳能电池的研制与应用技术、能量储存与能量控制系统、太阳能无人机机体平台设计技术。认为太阳能无人机作为航空科学技术与新能源技术相结合的产物,其研制过程需将气动、结构、推进、优化等多学科技术紧密结合。     

半导体激光陀螺关键技术的分析

现有激光陀螺产品的成本较高,而且难以小型化,原因如下：（1）光源采用氦氖激光器,体积较大,而且不利于长期存放,（2）必须采用高反射率的镜面（或全反射的棱镜）减小闭锁阈值,（3）剩余的闭锁阈值较大,必须增加偏频装置消除闭锁现象。在本文中,将探讨在激光陀螺中采用半导体光源和集成光电子器件的可行性,内容包括：（1）国外对半导体激光陀螺的实验研究,（2）半导体激光陀螺关键技术的分析,（3）半导体激光陀螺实验的设计。     

UC安全的移动卫星通信系统认证密钥交换协议

由于移动卫星和移动用户的计算、存储和通信能力有限,解决移动卫星通信系统的安 全和保密问题面临许多困难。根据移动卫星通信系统的实际情况,分析了系统的安全需求, 基于UC安全模型定义了移动卫星通信系统认证密钥交换协议的理想函数,该理想函数保证了 强安全性和实用性,并用于实际协议的设计。在移动用户和移动卫星通信网络控制中心之 间,设计了一个简单、低计算复杂性的认证密钥交换协议,该协议涉及了较少的交互次数, 认证协议计算负载仅仅需要利用伪随机函数、散列函数和与或计算。同时,基于UC安全模 型,对新的协议进行了可证明安全分析。新协议的安全属性包括可用性、有效性、身份隐藏 的可认证性、前向保密的密钥交换以及协议的模块化可复合性。     

适用于天地一体化网络的无证书密钥协商协议

为了保证天地一体化网络中用户信息的传输安全,改进传统方案的高时延等问题,本文提出一种轻量级的无证书密钥协商方案。首先,本文分析无证书密钥协商协议系统模型,针对天地一体化网络的特点提出协议需要满足双向认证、抗重放、完整性等安全需求。其次,本文选择一种轻量级的无证书加密方案,在此基础上提出密钥协商协议,满足天地一体化网络的资源和安全要求。最终,本文对提出的密钥协商协议进行BAN(Burrow-Adadi-Needham)逻辑安全性分析,并结合软件对协议性能仿真进行比较,结果表明：该方案在满足网络安全性需求的同时实现高效快速的协商。     

空间重复锁紧与分离装置容差性能分析与验证

空间重复锁紧与分离装置的容差能力是合作目标能否被捕获的关键指标,一定的容差能力能够抵消机械臂末端定位误差带来的合作目标位姿误差。根据某种在轨服务平台对空间合作目标的捕获方式,提出并设计了一种具有一定容差能力,并且在空间机械臂协助下能够完成对合作目标重复锁紧与分离的装置。本文建立了合作目标任意一点与重复锁紧与分离装置坐标系之间的D-H矩阵,完成了对球头关键点运动轨迹数学模型的建立。利用关键点投影方法对装置的容差性能进行分析,验证了装置设计的合理性。通过ADAMS仿真和样机试验相结合的方式对装置的容差性能进行验证,结果表明所设计的装置能够捕获和锁紧处于极限位姿下的合作目标,验证了装置的容差能力。     

组合动力空天飞行器关键技术

针对组合动力系统的工作特征和空天飞行器的任务特点,总结组合动力空天飞行器面临的主要问题,并梳理了该类飞行器存在的主要关键技术。从气动布局、机体/推进一体化、热防护/热管理、制导、控制、地面和飞行试验等方面,详细阐述各类关键技术存在的难点,总结各类技术的发展现状,并分析给出未来可能的发展途径和方向。相关研究可指导未来组合动力空天飞行器的技术攻关。     

自主可控关键软硬件在我国宇航领域的应用与发展建议

针对复杂国际形势与国内薄弱的工业基础,"十一五"以来我国通过"核高基"等国家科技重大专项持续投入,已在核心电子器件、基础软件产品、配套成套工艺等方面取得了重大突破.上海航天技术研究院作为航天装备主要研制单位,积极参与国家科技重大专项的实施,主动推动国产核心器件与操作系统软件的应用验证与型号应用,为国产关键软硬件研制平台...