Angular glint calculation and analysis of radar targets via adaptive cross approximation algorithm

Angular glint is a significant electromagnetic （EM） scattering signature of extended radar targets. Based on the adaptive cross approximation （ACA） algorithm accelerated method of moments （MoM） and the plane incident wave assumption, the narrowband, wideband and newly developed high-resolution range profile （HRRP） based angular glint calculation formulations are derived and applied to arbitrarily shaped three-dimensional （3D） perfectly electrical y conducting （PEC） objects. In addition, the near-field angular glint is emphasized, which is of great importance for radarseeker applications. Furthermore, with the HRRP based angular glint, an approach to rigorously determine range resolution cel s which own relatively smal er angular glint is provided. Numerical results are presented with new findings to demonstrate the usefulness of the developed formulations.     

一种环境激励下斜拉桥模型损伤识别方法

虚拟脉冲响应函数可表征环境激励下结构系统固有的动力特性,但桥梁试验模型空间变异的模糊性和测量过程中环境激励的随机性,使得虚拟脉冲响应函数同时具有随机不确定性和模糊不确定性,适用于随机-模糊统计原理处理.而Hilbert-Huang变换(HHT)是一种新的适用于非线性、非平稳信号且具有自适应性的数据处理方法.提出了基于HHT与虚拟脉冲响应函数随机模糊均值的结构损伤识别方法,并将4个Hilbert边际谱能量指标应用到室内斜拉桥模型的损伤识别中.结果表明:主梁损伤前后4种能量指标都发生了变化,且体现出相似的规律性,准确指示了较大程度损伤的损伤位置和程度,为大型桥梁结构在线监测提供了一种方法.     

煤层充水因素分析及矿井水害防治：以西山西铭煤矿为例

阐述了西铭矿的充水因素,包括含隔水层、充水水源、充水通道,对矿井主要水害提出了防治措施。     

基于S变换与PNN的电磁环境复杂度评估

针对复杂电磁环境定性分析和定量分级问题,提出基于广义S变换与PNN(概率神经网络)的电磁环境复杂度评估方法.应用广义S变换对电磁环境中受干扰的样本信号进行时频分析,同步提取时频域时域占用度,频域占用度和能量占用度评估参数,分析了各参数的物理意义,并给出了各评估参数的计算公式.同时增加频率重合度、调制格式相似度和背景噪声强度等评估参数,利用获取的参数训练PNN,并进行分类.仿真实验证明基于广义S变换与PNN的电磁环境复杂度评估方法在背景噪声大、训练样本数少的条件下能有效提取评估参数,并对电磁环境复杂度进行有效合理评估.     

武术运动员膝关节半月板损伤的分析及预防

随着武术运动的发展，武术运动员半月板损伤的问题日益突出，严重影响着运动员的技术水平、运动成绩和运动寿命，通过对有关资料的综合分析，着重从武术运动动作形态特征的角度，就武术运动员半月板损伤的多发动作和主要原因进行了探讨，以期为运动员的科学训练和有效预防提出建议。     

双环静电问题的分区分离变量解研究

本文研究了在球坐标系下用带电圆环面电荷密度表象、分区分离变量法解拉普拉斯方程及推广了的电磁边值关系，一般地求解任意取向轴线相交的带电双环静电问题，并由此给出了求解非对称静电问题的典型范例．     

SYT天然电磁波法在采空区探测中的应用

阐述了采用地球物理勘测方法--SYT天然电磁渡法确定采空区位置的做法,通过3种不同的处理方式,得出相应的地质图件,并对其进行分析研究,从而在地表对采空区的位置进行了确定.     

New Damage Localization Method for Bridges Using Vertical Support Reaction Data under Truck Load

The localization of damage for bridges to ensure their safety is investigated in this paper.Equivalent element concept is introduced into this study at the beginning.Support reaction data of each bearing under truck load are found to be able to lend themselves to indicate damage.A novel index termed as symmetrical support reaction difference index (SSRDI) is then developed.The reverse mapping between the local flexural stiffness change induced by damage and the SSRDI is generated.The proposed method based on SSRDI can be sensitive to tiny damages,and comparatively simple measurements are required during the application procedure.Another significant attraction of this method is that it can work in the presence of random uncertainties and actual support condition,which means it is suitable for real-world bridges.The effectiveness of the proposed method is demonstrated by numerical simulations performed on two kinds of bridges with reasonable damage severities.Its comparative advantage over the previous frequency method is also investigated.     

论行政赔偿范围的扩大

对我国目前的行政赔偿范围进行了反思。认为我国现行的《国家赔偿法》主要以列举方式确定的行政赔偿范围,极大限制了行政赔偿范围。建议采取“概括加否定排除式”的立法模式扩大行政赔偿范围,将行政规章以下的抽象行政行为、行政不作为行为和精神损害赔偿纳入行政赔偿范围。     

Calculation of angular glint in near field utilizing graphical electromagnetic computing

The angular glint in the near field plays an important role on radar tracking errors. To predict it more efficiently for electrically large targets, a new method based on graphical electromagnetic computing （GRECO） is proposed. With the benefit of the graphic card, the GRECO prediction method is faster and more accurate than other methods. The proposed method at the first time considers the special case that the targets cannot be completely covered by radar beams, which makes the prediction of radar tracking errors more self-contained in practical circumstances. On the other hand, the process of the scattering center extraction is omitted, resulting in possible angular glint prediction in real time. Comparisons between the simulation results and the theoretical ones validate its correctness and value to academic research and engineering applications.