Optimal index shooting policy for layered missile defense system

In order to cope with the increasing threat of the ballistic missile(BM)in a shorter reaction time,the shooting policy of the layered defense system needs to be optimized.The main decisionmaking problem of shooting optimization is how to choose the next BM which needs to be shot according to the previous engagements and results,thus maximizing the expected return of BMs killed or minimizing the cost of BMs penetration.Motivated by this,this study aims to determine an optimal shooting policy for a two-layer missile defense(TLMD)system.This paper considers a scenario in which the TLMD system wishes to shoot at a collection of BMs one at a time,and to maximize the return obtained from BMs killed before the system demise.To provide a policy analysis tool,this paper develops a general model for shooting decision-making,the shooting engagements can be described as a discounted reward Markov decision process.The index shooting policy is a strategy that can effectively balance the shooting returns and the risk that the defense mission fails,and the goal is to maximize the return obtained from BMs killed before the system demise.The numerical results show that the index policy is better than a range of competitors,especially the mean returns and the mean killing BM number.     

基于偏好DEA模型的应急资源优化配置

从应急系统中应急资源的投入产出的整体相对效率考虑, 提出了新的资源优化配置的非参数DEA模型,对应急系统中应急资源总体利用情况进行了评价.在此基础上,考虑到决策者的偏好信息,构造了偏好的DEA资源配置决策模型.最后,通过对一个算例的具体分析,清楚地表明,在资源总量控制的情况下,利用本文提出的非参数偏好DEA模型对应急资源进行统筹安排和合理配置,可以大大提高应急系统的整体相对效率.     

An impact angle constraint integral sliding mode guidance law for maneuvering targets interception

An integral sliding mode guidance law(ISMGL)combined with the advantages of the integral sliding mode control(SMC)method is designed to address maneuvering target interception problems with impact angle constraints.The relative motion equation of the missile and the target considering the impact angle constraint is established in the longitudinal plane,and an integral sliding mode surface is constructed.The proposed guidance law resolves the existence of a steady-state error problem in the traditional SMC.Such a guidance law ensures that the missile hits the target with an ideal impact angle in finite time and the missile is kept highly robust throughout the interception process.By adopting the dynamic surface control method,the ISMGL is designed considering the impact angle constraints and the autopilot dynamic characteristics.According to the Lyapunov stability theorem,all states of the closed-loop system are finally proven to be uniformly bounded.Simulation results are compared with the general sliding mode guidance law and the trajectory shaping guidance law,and the findings verify the effectiveness and superiority of the ISMGL.     

Finite-Time and Fixed-Time Synchronization of Inertial Neural Networks with Mixed Delays

This paper considers the drive-response synchronization in finite-time and fixed-time of inertial neural networks with time-varying and distributed delays(mixed delays). First, by constructing a proper variable substitution, the original inertial neural networks can be rewritten as a first-order differential system. Second, by constructing Lyapunov functions and using differential inequalities,some new and effective criteria are obtained for ensuring the finite-time synchronization. Finally, three numerical examples are also given at the end of this paper to show the effectiveness of the results.     

Timing Prediction Error Volatility and Dynamic Asset Allocation

We solve a portfolio selection,problem in which,return predictability,risk predictability and transaction cost are incorporated.In the problem,both expected return,prediction error volatility,and transaction cost are time-varying.Our optimal strategy suggests trading partially toward a dynamic aim portfolio,which is a weighted average of expected future tangency portfolio and is highly influenced by the common fluctuation of prediction error volatility(CPE).When CPE is high,the investor would invest less and trade less frequently to avoid risk and transaction cost.Moreover,the investor trades more closely to the aim portfolio with a more persistent CPE signal.We also conduct an empirical analysis based on the commodities futures in Chinese market.The results reveal that by timing prediction error volatility,our strategy outperforms alternative strategies.     

Optimal Grading Policies in the Online Acquisition of Used Products

Although online reverse commerce(recommerce)is convenient and efficient,it is not without caveats.It limits recommerce firms’flexibility to offer personalized prices and may cause mismatched grading between the firms and sellers of used products.This study examines a recommerce firm’s decision on grading criteria and prices.We find that the firm’s optimal policy exhibits two distinctly different patterns depending on the trade value of the product.We demonstrate that sellers’overestimate and underestimate errors have qualitatively different effects on firm profitability,and the effects crucially rely on the type of optimal policy.These findings can apprise firms on how to preset sorting criteria and prices as well as reduce grading errors.     

Evolutionary game analysis of problem processing mechanism in new collaboration

This paper analyzes a problem processing mechanism in a new collaboration system between the main manufacturer and the supplier in the"main manufacturer-supplier"mode,which has been widely applied in the collaborative development management of the complex product.This paper adopts the collaboration theory,the evolutionary game theory and numerical simulation to analyze the decision-making mechanism where one upstream supplier and one downstream manufacturer must process an unpredicted problem without any advance contract in common.Results show that both players'decision-makings are in some correlation with the initial state,income impact coefficients,and dealing cost.It is worth noting that only the initial state influences the final decision,while income impact coefficients and dealing cost just influence the decision process.This paper shows reasonable and practical suggestions for the manufacturer and supplier in a new collaboration system for the first time and is dedicated to the managerial implications on reducing risks of processing problems.     

地面站系统服务能力评估指标及其计算方法

针对地面站系统服务能力评估问题,研究了其评估指标及其计算方法.首先从卫星、地面站两个方面建立了地面站系统服务能力评估指标,并就各个指标以及指标的应用进行了分析.然后给出了两种指标计算方法:FCFS(First Come First Service)方法和启发式方法.最后通过实例仿真,表明该指标及方法能够较好的解决地面站系统服务能力评估问题中的是否增建新地面站、是否在某地面站中增加天线等重大决策问题.     

飞机朝后座椅的保护作用模型研究

为了进一步提高民航旅客运输的安全性和减少飞机事故的伤亡率,对飞机座椅朝后这一新概念,从安全防护的改善方面进行了系统分析和定量的描述,建立了冲撞缓冲效果的估算模型,进行了相关的简单试验,并分析了空难幸存案例,从中得出结论,如果把飞机座椅朝后安装,可以主动地、大幅度地提高事故中对人体的防护能力,减少伤害率.另外,通过比较发现,由此带来的改善,并不减少飞机原有的性能指标,也不增加成本和维护的复杂性.最后提出了分级布置飞机客舱座椅的建议,以便保留部分朝前的座椅供一些有偏好的旅客进行选择,使所有的座椅安全性都有所提高,起到了系统优化的作用.此模型为新一代面向用户的飞机设计,提供了一个系统安全分析的基础.     

Metropolis-Hastings自适应算法及其应用

首先阐述Metropolis-Hastings算法实现的具体步骤,然后证明由此产生的Markov链满足细致平衡条件,从而以目标分布为不变分布.接下来给出几个计算实例,以说明提议函数及其方差的选取对采样结果的影响,并由此推出一种改进的自适应算法用以寻找合适的提议函数及其方差.最后,通过贝叶斯Logistic模型的例子说明M-H方法在贝叶斯分析中的应用,同时也检验M-H自适应算法的效果.