Microstructural characterization of silicon carbide reinforced dissimilar grade aluminium explosive clads

Aluminium composites are inevitable in ship building, commercial and defence aircrafts construction due to their light weight, high strength to weight ratio, admirable properties and cost affordability. In this study, the microstructural characteristics of explosive cladded dissimilar grade aluminium (Al 1100-A1 5052) clad composites reinforced with silicon carbide (SiC) particles is presented. Microstructure taken at the interface by optical and scanning electron microscopes (SEM) revealed the formation of a silicon carbide layer between the dissimilar grade aluminium sheets. Though reaction layers were witnessed at few locations along the interface, the diffusion of atoms between the participant metals is not visible as confirmed by energy dispersive spectroscopy, elemental mapping, line analysis and X-ray diffraction (XRD). The variation in microhardness at various regions of the silicon carbide reinforced dissimilar aluminium explosive clad is reported. The increase in tensile strength of the SiC laced clad is also presented.     

Enhancing the explosive characteristics of a Semtex explosive by involving admixtures of BCHMX and HMX

A well-known ternary plastic explosive, Czech Semtex 1H, contains a mixture of PETN and RDX softened by SBR. In this work, BCHMX was used to replace PETN in Semtex 1H to form Sem-BC+RDX. In addition, another mixture based on BCHMX and HMX as energetic fillers bonded by the polymeric matrix of Semtex 1H (Sem-BC+HMX) was studied. The particle size distribution of each individual explosive was determined to obtain the optimum mixing conditions. Friction and impact sensitivities were determined. The velocity of detonation was reported practically and the detonation properties were calculated by EXPLO5 code. The explosive strength of each sample was measured by the ballistic mortar test. The conclusion confirms that the velocity of detonation of Sem-BC+HMX was the highest in comparison with the prepared samples. Sem-BC+RDX has the least impact and frictions sensitivities. Sem-BC+RDX has higher detonation velocity, detonation properties and explosive strength than Semtex 1H. Addition of BCHMX in Semtex 1H as a replacement for PETN is the candidate to produce a high performance advanced Czech plastic explosive.     

Clustering in defence-related procurement: the case of a Belgian naval construction cluster

ABSTRACT

This paper examines the importance of closer co-operation in defence-related procurement. Led by the decision that Belgium will lead the procurement of 12 Mine CounterMeasures Vessels (MCMV), the case of a potential Belgian naval construction cluster is discussed. The feasibility of a potential cluster is investigated by looking at key elements of a successful naval construction cluster, the Dutch naval construction cluster, and comparing those key elements to the current Belgian situation. Forming a sustainable Belgian naval construction cluster will be difficult. Most of the procurement process of the MCMVs is set on a European tender. In the long run, due to the absence of both a launching customer and leader firms, no party is able to carry the cluster with investments and knowledge spill-overs. In order to keep public support for large defence-related investments, clustering around the MCMV integration system and proactive cluster support is recommended.     

自组织特征映射网络在目标分类识别中的应用

为了在日趋复杂的空战环境中准确分析出目标的类型,以达到辅助决策之目的,采用自组织特征映射网络来对目标进行分类识别.首先提取影响目标识别的类特征,然后对其预处理.在此基础上建立SOM网络目标识别模型,并利用SOM网络算法实施无监督的自组织学习.在学习的过程中,通过不断调节网络节点间的权向量,来实现目标聚类.最后,通过仿真验证了该方法在目标分类识别中的可行性和实用性.     

杀爆弹对主战坦克毁伤评估仿真

在全面分析杀爆弹对主战坦克毁伤效应的基础上，针对冲击波和破片对坦克外部件的毁伤，利用计算机仿真方法进行杀爆弹对主战坦克毁伤评估。利用射击线技术构建了杀爆弹对主战坦克毁伤评估模型；基于蒙特卡洛随机模拟试验法，开发了计算程序，进行了以破片杀伤为主的杀爆弹对主战坦克毁伤效应仿真评估，得到了车体命中破片数随炸点坐标变化规律，以及坦克整体毁伤概率随杀爆弹终点速度变化规律。研究结果为主战坦克目标易损性分析与毁伤评估提供了重要参考。     

基于访问特征负载预测的负载均衡算法

为了提高web集群负载均衡的效果，结合web服务用户访问静动态内容的特征，提出了一种基于访问特征负载预测的负载均衡算法。首先建立网络带宽负载和CPU、内存综合性能负载的小波包一支持向量机回归混合预测模型；然后根据用户请求的类型，结合负载预测的结果对任务进行分配和调度。仿真结果表明：与传统的基于负载预测的负载均衡算法相比，基于访问特征负载预测的负载均衡算法能达到更好的负载均衡效果，从而有效提高web集群的整体性能。     

国民经济动员潜力的多元统计分析

选取了国民经济动员潜力的14个总指标进行因子分析，计算出各地区因子得分，并据此对各地区进行单项和综合因子排名，然后用聚类分析法将综合因子进行聚类，得出各地区潜力情况及分类，并就地区潜力进行了分析。     

系统评估效度分析的定量化方法

系统评估效度的定量化分析是评估后检验的有效方法,对于判断评估方法的相容性、评估结果的合理性具有重要意义。研究了等级相关系数法、兼容度优化法、肯德尔和谐系数法和模糊聚类法等4种效度分析方法的原理和步骤,分析了各种效度分析方法的优缺点,并通过实例验证了4种方法分析结果的一致性。     

防空导弹飞行试验的引战配合性能分析方法

提出了一种对防空导弹的引战配合性能进行量化评价的方法。利用飞行试验数据对导弹目标交会及战斗部杀伤目标过程进行了仿真。     

相似分布特性准则下的高斯混合项聚类-合并算法

针对高斯混合模型估计非高斯系统时高斯混合项呈指数级增长问题，提出一种基于相似分布特性准则的聚类-合并方法。通过分析高斯混合项的分布特性，基于扩展积分均方误差代价函数搜索最优置信范围，并对混合项进行高斯聚类，进而获得具有不同分布特性的高斯簇。为防止高斯簇间对高斯子项的重复利用，引入局部最近邻思想对交叉高斯项进行重新分配。采用并行多元素合并方法对高斯簇中的混合项进行合并，在保证无偏性基础上减少下一时刻混合项数量。仿真结果表明，改进算法在保证跟踪精度的同时还可有效提高算法效率。