一种适用于长基线的改进CIR算法

长基线下,受伪距多径和电离层残差影响,传统的CIR法解算载波相位宽巷模糊度时某些历元无法得到正确的结果,基础载波模糊度的搜索范围也较大。分析了CIR法的模糊度误差,提出了基于载波相位平滑伪距并且消除电离层时延的改进的CIR算法,分析了其误差方差,最后利用Compass系统实测数据对短基线和长基线两种情况下CIR法和改进CIR法的解算结果进行比较。实测数据表明,本文提出的算法能够单历元解算超宽巷模糊度和宽巷模糊度,并且能够大大缩小基础载波模糊度的搜索空间。     

Controlled warfare: how directed-energy weapons will enable the US Military to fight effectively in an urban environment while minimizing collateral damage

US military operations are increasingly conducted within urban environments and with these operations come the risk of increasing the number of civilian casualties and infrastructure damage. The use of non-lethal weaponry, such as directed-energy weapons, is one method for minimizing collateral damage. This method enables US military forces to effectively fight within urban environments through force escalation capabilities. Using a series of historical examples and future scenarios for urban warfare, this article highlights deficiencies affecting military capabilities in military urban operations, addresses the consequences of collateral damage, assesses the effectiveness of directed-energy weapons in military urban operations and encourages further funding, research and integration of non-lethal weaponry, such as directed-energy weapons, within the US military.     

水声目标机动检测与跟踪

当今海战场水声目标往往采用机动方式航行,打破了目标匀速直线运动假定的传统。通过对水声目标的机动模式分析,可将目标的运动轨迹近似为折线运动进行研究。提出了水声目标的机动检测与跟踪方法,简化机动检测的复杂度,最后讨论了对机动目标长时跟踪的策略。     

Making long-range planning work: the case of the US Army's 30-year strategic modernization plan

The extensive timespan of evolving assumptions about future adversaries, US military engagements, and technology inherent in the US Army's 30-year modernization strategy can overwhelm the management capacity of planners, and misdirect acquisition investments. Some military scholars have argued that long-range planning is futile due to the complexities of the global security environment. So how can the US Army manage the evolving assumptions inherent in its 30-year modernization strategy to ensure it remains a superior global force? This study will answer the above question by arguing that the US Army's 30-year modernization strategy, while emulative of a similar modernization approach in the threat-based planning environment of the Cold War, is viable if supported by a method and a tool that manage investments and planning assumptions.     

聚钛碳硅烷的结构与性能研究

通过聚碳硅烷与四丁氧基钛的反应。可以制得含钛碳化硅纤维的先驱体聚钛碳硅烷。反应物配比(Ti(OBu)_4)/PC 将直接影响产物的结构与性能。随这一比例的增加,聚钛碳硅烷的可纺性与熔点将有规律地变化。这可归因于以—Ti—O—为桥的交联结构和以—Ti(OBu)_3为侧基的悬挂结构的形成。本文研究了聚钛碳硅烷的结构与性能的关系,并以具有良好成丝性的PTC-0.02与PTC-0.04为先驱体,制得了含钛碳化硅纤维。     

前馈——模型参考自适应复合控制策略

由于多余力矩严重影响了电动负载模拟器的加载性能,提出了一种复合控制方法对该问题进行研究。首先考虑承载对象运动带来的干扰,建立了系统的数学模型;然后,针对控制系统单独采用前馈补偿或自适应控制方法的局限性,进行了基于前馈控制和模型参考自适应控制的复合控制系统设计,并利用Lyapunov函数的方法构造了自适应控制器。最后的仿真结果表明,采用复合控制方法能够大幅度消除电动负载模拟器的多余力矩,验证了控制策略的可行性。     

定期维护与事后修理组合的维修策略

为了客观合理地制定产品的定期维护与事后修理组合的维修策略,分析了该组合策略下产品的性能变化特点,并从失效机理出发,利用复合Poisson过程描述了产品性能退化规律,建立了以产品长期运行下费用率最低为目标的优化模型,并通过求解得到了最优的维护周期.最后,实例分析表明:该方法能够较好地描述产品的性能退化规律;同时,优化得到的维修策略值可以有效地降低维修费用,并延长产品使用寿命.     

步兵轻武器新型夜瞄复合荧光材料的性能研究

采用自制的复合荧光粉体和化学载体成分,研制出一种步兵轻武器新型夜瞄复合荧光材料.通过试验分别研究了新材料的发光性能、耐温性能、耐腐蚀性能和耐表面处理性能.试验结果表明,研制的新型夜瞄复合荧光材料发光时间长、亮度高,具有良好的耐温、耐腐蚀性能,不受武器表面处理的影响,可满足步兵轻武器夜间瞄准需求.     

Influence of high frequency pulse on electrode wear in micro-EDM

An electromagnetic coupling mathematical model is established by finite element method and is verified by the contrastive experiments of copper matrix Ni–TiN cylindrical coating electrode, copper electrode and Cu50W electrode. The wear mechanism of Ni–TiN/Cu composite electrode in the case of high-frequency pulse current is studied, and the influence of the fluctuation frequency of discharge current on electrode wear in micro-EDM is found out. Compared with the electrode made from homogeneous material, the high frequency electromagnetic properties of Ni–TiN composite layer can be used effectively to inhibit the effect of high frequency pulse on the electrode and improve the distribution trend of current density.     

寻找无向图中全部生成树的复合支路和网络撕裂技术

将复合支路和网络撕裂技术用于寻找无向图中全部生成树的算法.给出复合支路的概念、表示方法和运算规则,以及由各个子图的全部生成树得到原图的全部生成树的方法.在图的分解和找树过程中,可以采用并行算法,从而降低了找树算法的复杂性.