固定节点3D网格部署的水下传感器网络分簇路由算法

水下传感器网络是应用于水下通信的重要传感器网络技术。提出了基于固定节点3D网格部署的水下无线传感器网络分簇算法,设计了3D网格的编址和分簇方法,实现了基于地址分配的节点定位,构建了算法的能耗分析模型。采用MATLAB完成了算法的性能仿真,对比了DS-VBF、IAR和GEDAR 3个算法的平均数据传输延迟和网络生存时间(TTL)。实验结果表明,此算法的平均数据传输延迟较短,可明显提高UWSNS的生存时间。     

The rhetoric and practice of the international responsibility to prevent mass atrocities: Reflections on South Africa’s peacebuilding role in South Sudan (2005–2013)

While global consensus on the meaning and application of the responsibility to protect (R2P) principle remains tenuous, there is little contention among major actors that the development of the norm should prioritise the prevention of mass atrocities. In particular, Brazil, Russia, India, China and South Africa (BRICS) – which have a role to play that is vital to the future development of R2P as a global norm but which continue to express reservations about the intent and application of the doctrine – have been strong advocates of the preventive aspects of the principle. This rhetorical consensus, however, belies the conceptual and practical challenges that are associated with the prevention of mass atrocities. In this paper, the example of South Africa’s post-conflict reconstruction and development (PCRD) interventions in South Sudan from 2005 to 2013 is used to reflect on the role of external actors in supporting conflict-affected states to implement the preventive aspects of R2P. It is argued that while South Africa, like other BRICS countries, has used the rhetoric that atrocity prevention should be at the core of R2P to legitimise its opposition to military intervention for humanitarian purposes, it has struggled to back this rhetoric with coherent strategies and concrete actions to prevent mass atrocity crimes within its sphere of influence. The gap between rhetoric and practice in the preventive aspects of R2P is not unique to South Africa, but highlights fundamental difficulties inherent to global efforts to prevent mass atrocities.     

三维均匀化理论预测多孔混凝土等效弹性模量

应用多尺度渐进展开的均匀化理论,推导三维均匀化理论的有限元解法,求解复合材料等效弹性系数。假设多孔混凝土由光滑均匀一致的球孔与水泥石基质组成,提出改进的随机投放方法,生成三维均匀化理论求解的随机单胞模型。以聚苯乙烯泡沫(EPS)混凝土为数值算例,生成6组不同体积分数的EPS混凝土随机单胞模型,通过三维均匀化理论的有限元法计算得到其等效弹性模量。计算结果表明:随机单胞模型能反映细观的非均质性,三维均匀化理论的有限元法计算得到的等效弹性模量变化趋势比较符合Miled的试验结果。     

采用状态转移矩阵的拦截中段制导方法

基于相对运动理论提出拦截中段制导方法。方法原理为,将拦截器初始轨迹与施加修正后的轨迹视为一主一从两空间目标,以相对运动理论描述从目标相对于主目标的运动规律,于是初始的修正量可由终点处相对状态求解。给出了一般形式的相对运动模型,运用几何法与变分法推导得到了J2摄动影响下相对运动的状态转移矩阵,在此基础上,提出了采用状态转移矩阵的拦截中段制导方法。仿真算例表明,提出的方法能够为工程实际中的拦截中段制导提供有效支持。     

指挥控制系统中仿真决策系统的嵌入研究

将仿真决策系统嵌入到指挥控制系统中,利用仿真决策支持正在进行的军事行动正成为未来指挥控制系统发展的重要探索方向。研究了嵌入式仿真决策系统的组成,包括人机接口分系统、在线仿真分系统和控制管理分系统等;研究了嵌入式仿真决策系统的功能,包括计划与方案生成、作战态势读取、辅助指挥决策生成、战场态势预判、行动结果管理与未来态势生成控制等;研究了嵌入的关键技术途径,包括嵌入样式、在线仿真决策技术、定性与定量相结合的在线评估、面向服务的组件化设计等。研究成果对探索和建立我国未来新一代指挥控制系统具有重要、积极的现实和军事意义。     

某装备系统机电产品贮存可靠性评估方法

针对某装备系统机电产品长期自然贮存环境下可靠性无法准确评估的难题,提出了一种基于极小χ2估计和拟合优度检验的贮存可靠性评估方法,并对试验数据进行了分析、计算和处理。该方法通过拟合产品的失效分布来确定其分布函数参数,并根据确定的分布函数来预测产品的贮存可靠寿命。与现有的评估方法相比,采用该方法确定的分布函数更能反映产品的可靠性变化规律,对机电产品的贮存寿命预测结果更加合理,在工程研究领域具有很好的实用价值。     

指控系统中多操作系统启动工具的研究

指控系统中GRUB2作为启动引导器,管理多种操作系统平台。GRUB2采用模块化设计,可以提供给使用者更大的灵活性和性能改进。Linux系统的模块化设计与运行机制已被广泛讨论,有关GRUB2的模块化设计与运行机制的资料却很少。为了了解它的模块化编程与运行机制,通过对一个模块程序的分析,介绍了GRUB2中模块程序的基本结构及模块化设计的灵活性;并讨论了GRUB2的模块运行机制,明确了模块运行所需的底层工作。在此基础上,可以对GRUB2进行二次开发,扩展其应用场合。     

Supply licensing when the manufacturer strategically commits to invest in R&D

This article proposes a strategic reason for a proprietary component supplier to license her technology to a competitor or a manufacturer: her anticipation of the manufacturer's strategic commitment to invest in research and development (R&D). We address this phenomenon with a game theoretic model. Our results show that the manufacturer's full commitment to invest in R&D enables the supplier to license, sell a larger quantity through the supply chain, and charge lower prices. These results are robust to the type of demand uncertainty faced by the manufacturer within the class of increasing generalized failure rate distributions. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 341–350, 2014     

Some comparisons of residual life of coherent systems with exchangeable components

Most of the research, on the study of the reliability properties of technical systems, assume that the components of the system operate independently. However, in real life situation, it is more reasonable to assume that there is dependency among the components of the system. In this article, we give sufficient conditions based on the signature and the joint distribution of component lifetimes to obtain stochastic ordering results for coherent and mixed systems with exchangeable components. Some stochastic orders on dynamic (or conditional) signature of coherent systems are also provided. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 549–556, 2014     

基于旋量方法的高超声速飞行器三维非线性伪最优制导律设计

针对高超声速飞行器制导过程中的通道耦合问题,设计一种基于旋量方法的三维非线性伪最优制导律。引入角度矢量、视线旋量、视线旋量速度等概念,通过等价性证明,得出视线旋量、视线旋量速度控制分别与视线方位、视线角速度控制具有一致性的结论,从而将制导问题转化为视线旋量和旋量速度的控制问题;基于旋量方法构建弹目视线旋量、视线旋量速度模型,构建得到飞行器制导的三维非线性模型;为避免直接求解Riccati微分方程过程的复杂性,引入伪控制变量,将三维非线性制导模型转化为线性制导模型;分别针对无终端约束和有终端约束情况,基于二次型最优方法得到三维非线性伪最优制导律。该制导律避免了通道解耦,其制导参数又满足一定物理意义下的最优性。仿真结果验证了所设计制导律的有效性。