基于秘密共享的卫星网络组密钥管理方案

针对卫星网络组密钥管理的重要性,提出了一个可认证的基于门限秘密共享的组密钥管理方案．结合卫星网络的动态拓扑结构特点,将地面站作为组成员的身份注册中心,以实现对组成员的身份认证,确保节点的合法性．为了提高组密钥的生成效率,选取≠一1颗可见时间长的卫星构建组密钥份额分发中心,降低了组密钥联合生成过程中的通信量．组密钥协商无需安全信道,节省了系统资源．安全性及性能分析表明,该方案不仅具有较强的安全性,而且还具有计算和通信量小的优点．参数分析表明,门限值k与组密钥更新周期T是影响方案安全性的2个重要因子．     

舰载火箭炮子母弹射击火力分配模型

摘 要：由于舰载火箭弹的弹道特性与普通身管炮弹有着明显的差异,传统的舰炮射击效力计算及火力分配方法不适用于舰载火箭炮。结合舰载火箭弹弹道特点,分析了其射击误差,探讨了集群目标的简化处理方法,提出了一种基于蒙特卡洛法的舰载火箭炮对岸射击最优效力射火力分配计算模型。通过举例分析表明,该方法切实可行,利用该模型可以提高射击指挥员指挥决策的科学性。     

基于四元模糊数的鱼雷作战效能评估权重分析

权重计算是鱼雷作战效能评估中的一个关键问题,通常采用层次分析法计算指标权重.作为一种主观赋权方法,层次分析法忽略了专家经验的模糊性,基于此,提出了四元模糊数层次分析法确定指标权重.该方法将传统层次分析法判断矩阵的元素由一个确定的数推广到含有模糊信息的四元模糊数,并给出了方法模型和计算步骤.采用所提方法进行了鱼雷作战效能评估指标权重应用实例的计算,结果表明该方法是一种行之有效的权重计算方法.     

当前城中村消防安全问题分析及对策探讨

随着城镇化的快速发展,“城中村”火灾多发,形势严峻.对现阶段“城中村”的火灾特点进行了分析,结合工作实际,提出并分析了“城中村”存在的消防安全问题,就如何提升“城中村”抗御火灾能力提出了防火对策.     

学科类型、刺激对注意分配的影响

本研究从刺激类型、学科类型来探讨个体注意分配的差异。本研究采用2×2×2混合设计,其中学科(理科、文科)、性别(男生、女生)为组间变量、刺激类型(声刺激、光刺激)为组内变量;因变量为反应时。实验结果表明:不同学科类型学生的注意分配差异性显著,理科学生的注意分配反应时低于文科学生的注意分配能力;不同的刺激类型的注意分配差异显著,光选择反应的反应时低于声选择反应时;不同性别学生的注意分配能力的差异不显著。结论:学科类型、刺激类型影响个体的注意分配能力。     

基于删除平均的VI-CFAR检测器

针对MLVI-CFAR检测器在多个随机分布干扰目标背景下检测性能不好,以及OSVI-CFAR检测器在均匀环境和仅单滑窗存在干扰目标的环境下检测性能欠佳问题,提出了一种基于删除平均(CML)的VI-CFAR检测器(CMLVI-CFAR).仿真验证了CMLVI-CFAR检测器在均匀背景及多目标干扰环境下,都具有比MLVI和OSVI-CFAR检测器好的检测性能,并且其在杂波边缘背景下的虚警控制能力与前两者也基本一致,说明其在实际杂波环境中具有更强的鲁棒性和良好的应用潜力.     

A robust queueing network analyzer based on indices of dispersion

We develop a robust queueing network analyzer algorithm to approximate the steady-state performance of a single-class open queueing network of single-server queues with Markovian routing. The algorithm allows nonrenewal external arrival processes, general service-time distributions and customer feedback. The algorithm is based on a decomposition approximation, where each flow is partially characterized by its rate and a continuous function that measures the stochastic variability over time. This function is a scaled version of the variance-time curve, called the index of dispersion for counts (IDC). The required IDC functions for the external arrival processes can be calculated from the model primitives or estimated from data. Approximations for the IDC functions of the internal flows are calculated by solving a set of linear equations. The theoretical basis is provided by heavy-traffic limits for the flows established in our previous papers. A robust queueing technique is used to generate approximations of the mean steady-state performance at each queue from the IDC of the total arrival flow and the service specification at that queue. The algorithm's effectiveness is supported by extensive simulation studies.     

Effects of module number and firing condition on charge thermal safety in gun chamber

Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method.A two-dimensional cook-off model of modular charge in gun chamber is established and the cook-off process of modular charge in gun chamber is numerically simulated.Then the effects of module number and firing condition on charge thermal safety are evaluated by researching the cook-off response characteristics of modules.The results show that,under conditions of different module numbers the cook-off responses all occur on the module closest to the boundary of missile,and the single-base propellants located at the inner surface of cartridge ignite first.When the number of loaded module changes from 1 to 6,the cook-off response temperatures vary little,only in a small range of 478.1 K-482.4 K.The cook-off response times decrease logarithmically in the range of 211.2 s-166.7 s with the increasing length of residual air gap in gun chamber.The simulation results are well matched with the experimental data.Furthermore,different firing conditions have great influence on the cook-off response time,minor influence on the initial response position and little in-fluence on the response temperature.Under the three conditions of consecutive 32 launches with 5 rounds/min,43 launches with 1 round/min,and 41 launches with different firing frequencies,the cook-off response temperatures are 479.2 K,481.1 K and 479.9 K respectively and the response times are 709.2 s,211.2 s and 214.4 s respectively.The response position is near the middle area of the inner cartridge surface in the former condition and near the right area in the latter two conditions.     

Establishment,simulation and verification of firepower safety control model

On a narrow warship platform, the coordinated use of shipborne weapon systems may cause firepower conflicts, which seriously endangers the ship safety. Meanwhile, with directed-energy weapons mounted on ships, firepower conflicts between weapons become a “high probability event”. Aiming at the problem of firepower safety control, based on the research about the collision probability model of air crafts and space targets and according to the cone of fire model of conventional weapons and directed-energy weapons, this paper solved the firepower conflict probabilities between conventional weapons as well as between conventional weapons and directed-energy weapons respectively using the methods of probability theory, and established the firepower safety control model. Then the calculation of firepower conflict probability was carried out using the dimensionality reduction method based on the equivalent conversion of polar coordinates and the power series method based on Laplace transform. The simulation results revealed that the proposed model and calculation methods are effective and reliable, which can provide theoretical basis and technical support for resolution of firepower conflicts between weapons.     

早期可靠性数据的统计分析及其应用

在大型复杂产品研制过程中,通过原理样机的各类试验所获得的早期可靠性数据对产品早期可靠性的评估及可靠性设计具有重要意义。文中利用顺序约束模型研究了早期可靠性数据的处理方法,并将早期可靠性数据评估结果应用于可靠性增长计划的制定,从而有效减短了可靠性增长试验的时间。最后,给出了一个实际例子,以说明上述方法的应用。