浅析吸引系数法及其应用

本文通过对吸引系数法的分析,澄清了一个各种刊物在表述吸引系数法时的混淆,并提出了一种吸引系数法的改进方法,使之能够运用于野战指挥通信网中话音和数据业务量的建模。     

过模慢波结构高频特性

对过模结构在提高功率容量方面的优点进行了理论分析;分别采用解析方法和有限元方法研究了理想无限长过模慢波结构及有限长过模慢波结构色散关系的特点,对比了这两种情况下TM01模色散特性的区别,结果表明两者在纵向波数取值及对应的频率上有所差别,这对于高功率微波器件高频结构的设计有重要的参考价值。     

可变落点的再入机动飞行器姿控系统设计

基于选择的姿态反馈控制系统结构,从姿控系统稳定性能提高的角度,设计了控制系统反馈参数,以适应可变落点引起的飞行器参数变化。通过机动飞行器的六自由度飞行弹道仿真,表明所设计的姿态反馈控制系统控制效果较好,可适应预定区域内的飞行落点变化要求。     

离散系统的绝对稳定性

给出了离散系统绝对稳定性问题的充分条件:约束条件下的矩阵不等式的正定解;基于这一思路可以构造控制器来镇定一类非线性系统;最后还给出了设计实例以说明结果的有效性。     

Influence of a liquid-filled compartment structure on the incoming shaped charge jet stability

Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compart-ment structure can resist the shaped charge warhead effectively.This paper presents experimental and theoretical investigations of the penetration ability of the residual shaped charge jet emerging from the liquid-filled compartment structure after the penetration process at different impact angles.On the basis of shock wave propagation theory,the influence of the liquid-filled compartment structure on jet sta-bility is analysed.The interferences of the liquid backflow caused by a reflected shock wave and a back plate on jet stability under different impact angles are also examined.In addition,the range of the disturbed velocity segments of the jet at different impact angles and the penetration ability of the re-sidual jet are obtained.A theoretical model is validated against the experimental penetration depths.     

A comprehensive review on material selection for polymer matrix composites subjected to impact load

Polymer matrix composites (PMC) are extensively been used in many engineering applications. Various natural fibers have emerged as potential replacements to synthetic fibers as reinforcing materials composites owing to their fairly better mechanical properties, low cost, environment friendliness and biodegradability. Selection of appropriate constituents of composites for a particular application is a tedious task for a designer/engineer. Impact loading has emerged as the serious threat for the composites used in structural or secondary structural application and demands the usage of appropriate fiber and matrix combination to enhance the energy absorption and mitigate the failure. The objective of the present review is to explore the composite with various fiber and matrix combination used for impact applications, identify the gap in the literature and suggest the potential naturally available fiber and matrix combination of composites for future work in the field of impact loading. The novelty of the present study lies in exploring the combination of naturally available fiber and matrix combination which can help in better energy absorption and mitigate the failure when subjected to impact loading. In addition, the application of multi attributes decision making (MADM) tools is demonstrated for selection of fiber and matrix materials which can serve as a benchmark study for the researchers in future.     

采用局域像素匹配的随机抽样一致改进算法

为提高图像拼接的配准精度和稳健性,提出基于局域像素匹配的随机抽样一致改进算法。在完成尺度不变特征变换算子或其他算子图像特征提取、特征匹配之后,利用独立于特征匹配点的局域像素,通过参考图像局域像素与映射的待拼接图像局域像素匹配,优选4对最佳特征匹配点,确定最佳单应矩阵。实验结果表明:与随机抽样一致经典算法相比,该方法未明显增加计算耗时,单应矩阵更准确,图像拼接稳健性更好。     

超远程火炮安全装药多指标优化分析

通过计算分别建立了超远程火炮全装药和小号装药内弹道多目标(指标)优化模型,采用基于空间测度为标准的TOPSIS方法对方案进行了综合优化、排序,从而获得确保发射安全的满意装药方案。计算实例表明:TOPSIS方法是一种解多指标优化问题的有效方法,多指标优化模型可作为内弹道设计方案优化工具。     

高电阻率地域电气接地系统综合方案

电气接地是保障电气系统正常运行和设备安全的重要措施。在高电阻率地域,将接地电阻降到设计值非常困难。论述了综合利用构筑物的导电结构、新型人工接地材料,通过接地系统的总体优化,在减小接地电阻的同时,降低接地系统造价。还重点探讨了地下指挥工程接地系统的设计问题。为接地系统优化设计和工程应用提供借鉴。     

粘土的结构性与超固结

土体中的结构性与超固结都可以使土体表现出超固结特性。通过结构性与超固结对土体力学性质影响比较,揭示了它们对土体力学性质的影响存在本质差异,需要将它们区分开来。基于土体中的结构性、超固结对土体固结特性的影响差异及粘土的正常固结线的唯一性,提出了粘土的结构性与超固结的定量描述方法,据此对原状粘土进行分类。土体的结构性主要包括土体的化学胶结等真正改变了土样结构的因素,用结构性参数来定量描述,而次固结、干缩作用可看成与超固结作用一致,一起用超固结参数来定量描述。