空间站平均力矩平衡姿态的气动力矩影响

为了研究空间站平均力矩平衡姿态的影响因素,建立了空间站的姿态运动模型,分析了气动力矩对空间站平均力矩平衡姿态的影响。建立了空间站的动力学与控制模型,采用典型的比例微分控制器,分别得出了两种条件下的24组平均力矩平衡姿态(Average Torque Equilibrium Attitude,ATEA),结果表明气动力矩对ATEA的影响显著。为了保持空间站ATEA,需要提供周期性的控制力矩。气动力矩引起的空间站角动量卸载和积累效应不能被忽视。     

Asymmetric information and third-party intervention in civil wars

I study a two-period model of conflict with two combatants and a third party who is an ally of one of the combatants. The third party is fully informed about the type of her ally but not about the type of her ally’s enemy. In a signaling game, I find that if the third party is unable to give a sufficiently high assistance to her ally, then there exists a unique separating equilibrium in which the third party’s expected intervention causes her ally’s enemy to exert more effort than in the absence of third-party intervention; this worsens the conflict.     

高空远程滑翔UUV减速段弹道仿真与分析

高空远程滑翔UUV技术是一种集高空滑翔与水下航行于一体的综合技术研究,减速段弹道是高空远程滑翔UUV弹道流程中的重要部分.通过建立高空滑翔UUV的六自由度数学模型,在Matlab/Simulink环境下对减速段弹道进行了运动仿真与分析.采用火箭反推减速方案对UUV进行减速,根据UUV入水条件要求设置初始条件,仿真结果显示UUV能满足入水条件要求,证明了此方案的可行性.并对影响减速段弹道的因素:反推力的大小、反推力作用时间、反推火箭安装位置进行了仿真与分析,对以后的进一步研究具有指导意义.     

军事云环境下基于动态博弈的资源调度方法

针对军事云环境下联合指挥资源调度优化问题,综合考虑了多部队任务需求,多目标优化,多部队资源竞争等约束条件,运用动态博弈理论及方法,建立并提出了一种基于完全信息扩展博弈的资源调度模型及方法,提高了资源调度效率,兼顾了多部队利益,增加了联合作战效益。最后通过实验验证了其有效性及准确性。     

Inducing coordination in supply chains through linear reward schemes

Decentralized decision‐making in supply chain management is quite common, and often inevitable, due to the magnitude of the chain, its geographical dispersion, and the number of agents that play a role in it. But, decentralized decision‐making is known to result in inefficient Nash equilibrium outcomes, and optimal outcomes that maximize the sum of the utilities of all agents need not be Nash equilibria. In this paper we demonstrate through several examples of supply chain models how linear reward/penalty schemes can be implemented so that a given optimal solution becomes a Nash equilibrium. The examples represent both vertical and horizontal coordination issues. The techniques we employ build on a general framework for the use of linear reward/penalty schemes to induce stability in given optimal solutions and should be useful to other multi‐agent operations management settings. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

可控翼伞系统的滑翔与稳定性分析

可控翼伞系统在飞行器回收领域有广阔的应用前景。本文就可控翼伞系统建立了六自由度数学模型,并用该模型对40m~2可控翼伞系统的滑翔和稳定性进行了仿真计算和分析,研究结果对可控翼伞系统设计和实验有一定参考价值。     

潜艇定深运动的自适应模糊控制研究

针对潜艇定深运动过程中存在非线性、时变参数、复杂干扰的特点,提出了一种基于神经网络的自适应模糊控制器,并采用学习速率自调整的EBP算法对模糊控制器进行了在线调整.仿真结果表明,该控制器能辨别出潜艇的平衡舵角,与常规的PID控制相比,具有抗干扰能力强、响应速度快、精度高等优点.     

高超声速滑翔再入飞行器的可达区快速预测

防御方对来袭滑翔再入飞行器进行可达区的预测存在先验信息量不足且时效性要求高等难题。为此提出一种基于最优化飞行假设的可达区快速预测方法:仅需已知目标当前位置、速度与最大升阻比(可基于雷达探测数据通过实时弹道估计获得),基于平衡滑翔假设和最大横程的埃格斯解分别获得目标最大纵程和横程终点坐标,在经纬度二维平面内,可达区即可近似为以两个最大横程终点间线段为短轴、最大纵程终点到短轴距离为半长轴的半椭圆区域。仿真结果表明,与传统的数值优化方法和常倾侧角方法相比,提出的方法具有利用先验信息少、精度较高和运算量小的优点,可满足实时性要求。     

Oligopolistic contracting: Channel coordination under competition

We study contracts between a single retailer and multiple suppliers of two substitutable products, where suppliers have fixed capacities and present the retailer cost contracts for their supplies. After observing the contracts, the retailer decides how much capacity to purchase from each supplier, to maximize profits from the purchased capacity from the suppliers plus his possessed inventory (endowment). This is modeled as a noncooperative, nonzero‐sum game, where suppliers, or principals, move simultaneously as leaders and the retailer, the common agent, is the sole follower. We are interested in the form of the contracts in equilibrium, their effect on the total supply chain profit, and how the profit is split between the suppliers and the retailer. Under mild assumptions, we characterize the set of all equilibrium contracts and discuss all‐unit and marginal‐unit quantity discounts as special cases. We also show that the supply chain is coordinated in equilibrium with a unique profit split between the retailer and the suppliers. Each supplier's profit is equal to the marginal contribution of her capacity to supply chain profits in equilibrium. The retailer's profit is equal to the total revenue collected from the market minus the payments to the suppliers and the associated sales costs.     

涡轮增压机组的功率平衡计算方法

介绍了舰船蒸汽动力装置中增压锅炉的计算特性,并在对已有的一些相关计算模型分析的基础上,描述了涡轮增压机组的功率平衡计算难题。针对该难题给出了涡轮增压机组的功率平衡计算流程和计算中有关问题的处理方法,在确保计算完备可行的前提下,该方法适合于工程应用。