L+1容错恢复策略在复杂军事网络中的应用仿真

以标准3×3网格为基础网络,介绍了L+1容错恢复策略的概念和恢复原理,以海上舰艇编队作战系统网络为研究对象,使用Matlab-Simulink仿真工具,通过对阻塞概率、平均路径长度、路径重新分配概率和有效利用率4个指标的仿真,对比了该网络在无策略、备份多路和L+1容错恢复3种策略下网络的恢复程度,验证了L+1容错恢复策略的有效性和可行性。     

八轮MISTY1算法的相关密钥扩大飞来去器攻击

密钥扩展算法对分组密码的安全至关重要,目前各种攻击方法越来越关注密钥带来的影响.通过分析非线性函数FI和密钥扩展算法,并观察轮子密钥的排列方式,寻找到MISTY1算法一个包含290个弱密钥的、可应用于相关密钥扩大飞来去器攻击的弱密钥类.在弱密钥类的基础上,寻找到两条相互独立的相关密钥差分路径,从而构造了一个七轮MISTY1算法的相关密钥扩大飞来去器区分器,进而实现了对八轮MISTY1算法(不带最后FL层)的相关密钥扩大飞来去器攻击.攻击需要263个选择明文,攻击的计算复杂度是270.该攻击是第一个对不带最后FL层MISTY1算法的八轮攻击,且与同类攻击方法相比,攻击算法放宽了所需要的相关密钥的限制条件.     

单舰反导作战能力评估模型初探

水面舰艇海上作战的主要威胁来自于敌方反舰导弹的攻击,因而水面舰艇的反导作战能力成为其战斗能力和生存能力的重要指标之一.根据单舰反导武器系统的特点,建立了单舰在遭受单发导弹攻击和多发导弹攻击情况下的反导作战能力评估模型.     

Capacity investment decisions under risk aversion

This article studies the optimal capacity investment problem for a risk‐averse decision maker. The capacity can be either purchased or salvaged, whereas both involve a fixed cost and a proportional cost/revenue. We incorporate risk preference and use a consumption model to capture the decision maker's risk sensitivity in a multiperiod capacity investment model. We show that, in each period, capacity and consumption decisions can be separately determined. In addition, we characterize the structure of the optimal capacity strategy. When the parameters are stationary, we present certain conditions under which the optimal capacity strategy could be easily characterized by a static two‐sided (s, S) policy, whereby, the capacity is determined only at the beginning of period one, and held constant during the entire planning horizon. It is purchased up to B when the initial capacity is below b, salvaged down to Σ when it is above σ, and remains constant otherwise. Numerical tests are presented to investigate the impact of demand volatility on the optimal capacity strategy. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 218–235, 2016     

Concise RLT forms of binary programs: A computational study of the quadratic knapsack problem

The reformulation‐linearization technique (RLT) is a methodology for constructing tight linear programming relaxations of mixed discrete problems. A key construct is the multiplication of “product factors” of the discrete variables with problem constraints to form polynomial restrictions, which are subsequently linearized. For special problem forms, the structure of these linearized constraints tends to suggest that certain classes may be more beneficial than others. We examine the usefulness of subsets of constraints for a family of 0–1 quadratic multidimensional knapsack programs and perform extensive computational tests on a classical special case known as the 0–1 quadratic knapsack problem. We consider RLT forms both with and without these inequalities, and their comparisons with linearizations derived from published methods. Interestingly, the computational results depend in part upon the commercial software used. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

基于0-1规划的弹种决策与发射时序优化

对于身管发射武器系统,同一发射单元使用不同弹种完成作战任务时,需要确立合适的弹种决策与最佳的发射时机.提出用O-1变量来描述弹种决策变量.通过时弹种发射机制及武器系统控制特点进行分析,构造多种0-1变量用以描述武器系统作战时序之间的约束关系,建立了弹种发射时序的0-1规划模型,并用LINGO软件实现了0-1规划的求解.给出了典型应用实例,进行了仿真计算,结果表明,该方法简单可行.     

功能化离子液体的合成表征及其作为润滑剂的性质

通过两步法合成了含酯基官能团的咪唑类离子液体1-乙酸乙酯基-3-甲基咪唑四氟硼酸盐,用核磁共振、红外光谱、元素分析对其进行了结构表征,证明了该合成方法的可靠性;对功能化离子液体的基本物化性质、熔点、热稳定性及其作为润滑剂的粘温性、蒸发损失、金属腐蚀性等进行了全面研究,并选择了含有相同烷基的1-丁基-3-甲基咪唑四氟硼酸盐传统离子液体进行对比,发现官能团的引入,使传统烷基咪唑类离子液体展现出不同的特性,同时发现两种离子液体均对金属表面有较强的腐蚀作用,为进一步开展功能化离子液体的摩擦学研究打下了基础。     

新型硫代双烯镍络合物合成及其对菁染料的光稳定作用

在合成中间体二(4-叔丁基苯基)羟乙酮基础上,进一步合成了双(1,2-二(4-叔丁基苯基)-1,2-二硫代双烯)镍络合物(DYE-02),利用核磁共振氢谱、红外光谱和元素分析等方法对中间体及DYE-02的结构进行了表征,并研究了DYE-02自身的光稳定性能及其对菁染料(Cy7)的光稳定作用.结果表明,与双(1,2-二苯基-1,2-二硫代双烯)镍络合物(DYE-01)相比,苯环上引入叔丁基后,DYE-02的最大近红外吸收波长在885nm,发生明显的红移,具备更好的自身光稳定性,并且能明显提高菁染料的光稳定性.     

1,4 -二乙炔苯与1,4-丁炔二醇的共聚及表征研究

本文以(Ph_3P)_2 PdCl_2为催化剂,用各种比例的对二乙炔苯(DEB)与1,4-丁炔二醇(BD)合成出共聚物及两种单体的均聚物。共聚物为褐黑色,不溶不熔。单体配比中DEB比例越高,共聚物交联度和比重越大,产率越高,溶胀度越小。单体摩尔比DEB/BD≥1/2时,共聚物最良溶剂为苯,溶度参数(δP)为9.15卡~(0.5)·cm~(-1.5),而DEB/BD=1/5时,共聚物最良溶剂为无水乙醇,8p=12.7卡~(0.5)·cm~(-1.5).对均聚物及共聚物做了红外光谱表征并讨论了聚合反应机理。     

Saudi Arabia's defence offset programmes: Progress,policy and performance

This paper discusses the performance of Saudi Arabia's defence offset programmes. The Kingdom is involved in some of the World's biggest defence offset agreements and a review of the problems it has faced and the policies it has introduced provides a useful insight into that part of the international defence market where trade and development meet.

The paper reviews the origins and development of Saudi Arabia's major defence offset programmes. Saudi policies towards defence offsets are outlined before assessing the practical impact of the programmes themselves. The author concludes that Saudi Arabia's offset projects have had only a minor impact on the Kingdom's economy to date and makes a number of policy recommendations which are designed to enhance the utility of the programmes in the Kingdom's drive to enhance and diversify the technological base of its economy.