一种改进固定单站无源定位模型性能分析

针对固定单站无源定位中的DPFRC算法无法对目标辐射源速度进行直接解算的问题,将多普勒频率引入观测量之中,提出一种改进的固定单站无源定位模型,并通过卡尔曼滤波对定位结果进行平滑处理。将改进模型与原有模型及另外一种可对速度进行直接解算的DDFRC模型进行了仿真比较,对不同距离、不同采样间隔和不同观测精度下3种模型的性能进行了仿真分析。仿真结果表明,相比于另外两种定位模型,改进模型具有更为广泛的应用环境和更好的鲁棒性。     

Hilbert空间中Lipschitz拟伪压缩映像公共不动点的杂交投影算法

给出了Hilbert空间中Lipschitz拟伪压缩映像族公共不动点的一个投影算法，并利用所给出的算法证明了一个强收敛定理，扩展了参考文献[1]的结果。     

指令制导防空炮弹启控点参数的确定方法

简要阐述了指令制导防空炮弹有控弹道控制模式,建立了鸭舵控制力和控制力矩作用下的有控弹道模型,研究了弹丸理想启控姿态和启控位置的确定方法,得到了确定理想启控位置的启控函数.数值仿真结果表明,该启控函数简单、快速,具有较高精度,易于计算机程序实现,弹丸有控弹道也可保持飞行稳定.研究结果对今后深入展开指令制导防空炮弹的研究和工程设计具有一定的参考意义.     

新疆固定资产投资环境与趋势分析

截止目前，新疆固定资产投资运行情况比较平稳，与全国相比，投资增速处于中等水平。全社会固定资产投资预计完成1595亿元，增长18％。建成和开工建设了一大批重大基础设施和重点基础产业项目，投资结构进一步改善，农业、水利、交通、能源、生态建设、社会事业等薄弱环节投资力度明显加大，生态环境保护建设取得明显成效。     

A componentwise index of service measurement in multi‐component systems

In this paper we present a componentwise delay measure for estimating and improving the expected delays experienced by customers in a multi‐component inventory/assembly system. We show that this measure is easily computed. Further, in an environment where the performance of each of the item delays could be improved with investment, we present a solution that aims to minimize this measure and, in effect, minimizes the average waiting time experienced by customers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 50: 2003     

滑模控制的新型双幂次组合函数趋近律

提出一种基于双幂次组合函数趋近律的新型滑模控制方案。与现有的快速幂次或双幂次趋近律相比,具有更快的收敛速度,同时还保持了全局固定时间收敛特性,收敛时间上界与滑模初值无关。当系统存在有界扰动时,能够使滑模变量在有限时间内收敛到稳态误差界内,同时其稳态误差要小于现有方法的。仿真实验验证了该方法的有效性及理论分析的正确性。     

Asymptotic analysis of periodic policies for the inventory routing problem

In this article, a distribution system is studied where the sum of transportation and inventory costs is to be minimized. The inventory holding cost is assumed to be the same for all retailers. A fixed partition (FP) periodic policy is proposed with tight asymptotic worst‐case performance of 3/2 with respect to the best possible policy. This bound cannot be improved in the class of FP periodic policies. In partition‐based PB policies, the retailers are first partitioned into sets and then the sets are grouped in such a way that sets of retailers within a group are served together at selected times. A PB periodic, policy is presented with tight worst‐case asymptotic performance of with respect to the best possible policy. This latter performance improves the worst‐case asymptotic performance of of the previously best known policy for this problem. We also show that the proposed PB periodic policy has the best worst‐case asymptotic performance within the class of PB policies. Finally, practical heuristics inspired by the analyzed policies are designed and tested. The asymptotic worst–case performances of the heuristics are shown to be the same of those of the analyzed policies. Computational results show that the heuristics suggested are less than 6.4% on average from a lower bound on the optimal cost when 50 or more retailers are involved. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 00: 000–000, 2013     

具有集值H-半-伪单调映射的广义向量变分不等式解的存在性

首先推广向量集值半一单调映射到向量集值H-半-伪单调映射,然后利用Kakutani—Fan—Glicksberg不动点定理,研究了具有集值H-半-伪单调映射的广义向量t变分不等式问题,在自反Banach空间中得到了两个存在性结果。     

一类m-点边值问题的正解

研究一类二阶m-点边值问题u″ f(t,u,u)′=0,00,i=1,…,m-2,ζi满足0=ζ0<ζ1<ζ2<…<ζm-2<ζm-1=1和i∑=1aiζi<1。应用推广的Krasnosel-skii′s不动点定理,给出了上述边值问题至少存在一个正解的充分条件。     

Incomplete contracting and target‐cost pricing

Procurement of advanced technology defence equipment requires appropriate contractual arrangements to achieve efficient R&D investments. This paper analyses the optimality of target‐cost and fixed price contracts and shows that target‐cost pricing can achieve a first best where both fixed‐price contracts and cost reimbursement fail to do so. The main message of this paper is that in incomplete contracting optimality may sometimes be achieved by arrangements which combine several formulae which, individually, would fail to achieve efficiency.