Allocation with demand competition: Uniform,proportional, and lexicographic mechanisms

We examine capacity allocation mechanisms in a supply chain comprising a monopolistic supplier and two competing retailers with asymmetric market powers. The supplier allocates limited capacity to retailers according to uniform, proportional, or lexicographic mechanism. We study the impact of these allocation mechanisms on supplier pricing decisions and retailer ordering behavior. With individual order size no greater than supplier capacity, we show that all three mechanisms guarantee equilibrium ordering. We provide precise structures of retailer ordering decisions in Nash and dominant equilibria. Further, we compare the mechanisms from the perspective of the supplier, the retailers, and the supply chain. We show that regardless of whether retailer market powers are symmetric, lexicographic allocation with any priority sequence of retailers is better than the other two mechanisms for the supplier. Further, under lexicographic allocation, the supplier gains more profit by granting higher priority to the retailer with greater market power. We also extend our study to the case with multiple retailers. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 85–107, 2017     

小子样条件下战斗部爆炸仿真数据可信性分析

高效毁伤战斗部试验次数受到严格控制,如何在小子样条件下分析仿真数据的可信性非常有必要。通过均匀试验得到了战斗部在地下目标腔室内部爆炸某点冲击波最大超压峰值,利用normplot及Lilliefors函数分析了仿真数据的分布特征,而后在已有检验方法的基础上,结合顺序统计量和均匀分布的特点提出了一种新的相容性验证思路。研究表明:该方法不受样本容量的限制,利用MATLAB程序编程可以快速判断仿真数据的可信性。     

Convolutions and generalization of logconcavity: Implications and applications

Additive convolution of unimodal and α‐unimodal random variables are known as an old classic problem which has attracted the attention of many authors in theory and applied fields. Another type of convolution, called multiplicative convolution, is rather younger. In this article, we first focus on this newer concept and obtain several useful results in which the most important ones is that if is logconcave then so are and for some suitable increasing functions ?. This result contains and as two more important special cases. Furthermore, one table including more applied distributions comparing logconcavity of f(x) and and two comprehensive implications charts are provided. Then, these fundamental results are applied to aging properties, existence of moments and several kinds of ordered random variables. Multiplicative strong unimodality in the discrete case is also introduced and its properties are investigated. In the second part of the article, some refinements are made for additive convolutions. A remaining open problem is completed and a conjecture concerning convolution of discrete α‐unimodal distributions is settled. Then, we shall show that an existing result regarding convolution of symmetric discrete unimodal distributions is not correct and an easy alternative proof is presented. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 109–123, 2016     

均匀分布法对集群目标射击效率计算积分表达式

为简化炸点均匀分布条件下对集群目标射击效率计算的表达式,采用"化四个象限积分为一个象限积分"的方法,导出射击幅员在正面和纵深上覆盖集群目标比值数学期望的积分表达式,在此基础上讨论对单个目标毁伤概率计算公式和对集群目标毁伤百分比计算的近似公式,导出射击幅员在正面和纵深上覆盖集群目标比值二阶矩的积分表达式,给出了对集群目标射击效率的算例。结论改进了对集群目标射击效率计算的方法。     

具有时滞和扩散的动力系统的全局稳定性

研究一类具有时滞和扩散的非自治Ⅲ类功能性反应系统,给出了系统一致持久和全局渐近稳定的充分条件。     

信号的直接采样理论

经典的采样定理建立了带限信号与其均匀采样值之间的联系。本文对采样定律作了三点补充 :1)给出在定理条件不满足时 ,由均匀采样值恢复的信号与原信号的误差表达式 ;2 )用简洁的方法分析了带通信号的均匀采样问题 ,得到了采样率应满足的条件 ;3)研究了一种特殊的非均匀采样情况 ,给出了采样率的可取范围以及由非均匀采样重构原信号的公式。这些都是对经典采样定理的丰富和深化。     

引入优化算子的无人机遗传航路规划算法研究

在大范围真实地形环境中规划出满足任务要求、导航、安全性等约束的较优航路,对提高无人机(UAV)的武器系统性能有重要意义。在基于直接航路编码的遗传算法中引入优化操作算子,将复杂约束合理地应用于遗传进化过程,可以较好地克服一般遗传操作的不足。采用均匀设计的试验方法确定较优的控制参数,并通过算例验证了算法的有效性。     

水下监测系统中的特殊均匀圆阵特性分析

一种特殊的均匀圆形阵列(SUCA)安装在水下监测系统中的浮体系统上。针对SUCA的特殊性,建立了SUCA的模型,运用模式空间理论推导出其方向图公式,并在此基础上对其半功率波束宽度和无模糊条件进行了研究和分析。通过与均匀圆形阵列(UCA)进行比较,得出结论:SUCA半功率波束宽度略大于UCA,并且其无模糊条件比UCA范围更广。研究表明SUCA的性能与UCA相似,具有工程实用价值。     

低速凤洞均匀抽吸地板系统

在KD－03低速风洞中研制了一种附面层可人为地控制的均匀抽吸地板系统。在不同来流速度和不同抽吸系数条件下，对均匀抽吸地板上附面层速度分布进行了实验研究。实验结果与理论计算结果一致。在该地板上的高速列车模型风洞实验的结果与国外同类模型在移动带地板上的实验结果一致。利用均匀抽吸地板可有效地消除阻面层的影响，从而提高模型风洞实验气动力的试验精度。     

基于磁记忆的铁磁性构件定量无损检测研究

为提高磁记忆检测结果的稳定性,设计匀速采样系统,并且针对系统的实验结果进行分析。由实验结果得出提离值对系统稳定性的影响较小,扫描速度对检测结果稳定性的影响较大。