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101.
软件无失效测试数据的统计分析 总被引:2,自引:0,他引:2
张志华 《海军工程大学学报》2003,15(6):21-24
软件可靠性估计是软件可靠性研究的重要问题之一,文中对分布式软件系统可靠性的评估方法进行了研究,给出了软件系统可靠度的最优置信下限.最后以某大型软件的评估为例,说明该方法的应用. 相似文献
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基于微分对策理论设计了躲避护卫弹的同时攻击飞行器的制导律。根据传统的性能指标推导了该场景的微分对策制导律,并且根据权重系数的取值定义了三种制导律:最优追赶制导律、逃脱-追赶制导律和复合制导律。最优追赶制导律容易被护卫弹拦截,逃脱-追赶制导律容易造成导弹和飞行器的零控脱靶量急剧增大而使得攻击失败,复合制导律很难选择合适的权重系数。针对以上不足,提出了两种改进的制导律,并对该两种制导律的适用情况进行了分析。通过非线性模型仿真,验证了这两种方法的可行性。该两种制导律目的性强,攻击导弹可以躲避护卫弹进而攻击飞行器。 相似文献
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针对高超声速滑翔导弹跟踪中状态模型构建问题,研究基于制导变量变化规律的气动参数建模方法。对气动参数进行分析,指出传统建模方法的缺点。在假设制导变量服从一阶时滞过程的前提下,利用线性化的气动系数推导气动参数模型,通过分析不同飞行状态下的模型变式,证明模型对目标机动具有自适应性。对模型中未知参数的取值问题进行讨论,实现模型与飞行状态的自适应匹配。仿真结果表明:当目标发生机动时,所提模型性能明显优于传统模型。同时,在不同滤波器参数条件下的仿真结果进一步证实了模型的有效性。 相似文献
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We consider a two‐echelon inventory system with a manufacturer operating from a warehouse supplying multiple distribution centers (DCs) that satisfy the demand originating from multiple sources. The manufacturer has a finite production capacity and production times are stochastic. Demand from each source follows an independent Poisson process. We assume that the transportation times between the warehouse and DCs may be positive which may require keeping inventory at both the warehouse and DCs. Inventory in both echelons is managed using the base‐stock policy. Each demand source can procure the product from one or more DCs, each incurring a different fulfilment cost. The objective is to determine the optimal base‐stock levels at the warehouse and DCs as well as the assignment of the demand sources to the DCs so that the sum of inventory holding, backlog, and transportation costs is minimized. We obtain a simple equation for finding the optimal base‐stock level at each DC and an upper bound for the optimal base‐stock level at the warehouse. We demonstrate several managerial insights including that the demand from each source is optimally fulfilled entirely from a single distribution center, and as the system's utilization approaches 1, the optimal base‐stock level increases in the transportation time at a rate equal to the demand rate arriving at the DC. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011 相似文献
105.
Given a number of patrollers that are required to detect an intruder in a channel, the channel patrol problem consists of determining the periodic trajectories that the patrollers must trace out so as to maximized the probability of detection of the intruder. We formulate this problem as an optimal control problem. We assume that the patrollers' sensors are imperfect and that their motions are subject to turn‐rate constraints, and that the intruder travels straight down a channel with constant speed. Using discretization of time and space, we approximate the optimal control problem with a large‐scale nonlinear programming problem which we solve to obtain an approximately stationary solution and a corresponding optimized trajectory for each patroller. In numerical tests for one, two, and three underwater patrollers, an underwater intruder, different trajectory constraints, several intruder speeds and other specific parameter choices, we obtain new insight—not easily obtained using simply geometric calculations—into efficient patrol trajectory design under certain conditions for multiple patrollers in a narrow channel where interaction between the patrollers is unavoidable due to their limited turn rate.© 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011 相似文献
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惯导信息短期精度高、稳定性好,且自主工作,不受外界电磁干扰.基于惯导的这些特点,提出了一种利用惯导位置、速度信息辅助抗舷外干扰的信息处理方法:在反舰导弹末制导跟踪阶段,建立弹目相对运动模型,通过扩展卡尔曼滤波降低雷达导引头随机测量误差,获取目标位置和速度信息,当检测到干扰,通过对目标位置的预测和惯导对导弹位置的确定,实... 相似文献
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