Aircraft vulnerability modeling and computation methods based on product structure and CATIA

Survivability strengthening/vulnerability reduction designs have become one of the most important design disciplines of military aircraft now. Due to progressiveness and complexity of modern combat aircraft, the existing vulnerability modeling and computation methods cannot meet the current engineering application requirements. Therefore, a vulnerability modeling and computation method based on product structure and CATIA is proposed in sufficient consideration of the design characteristics of modern combat aircraft. This method directly constructs the aircraft vulnerability model by CATIA or the digital model database, and manages all the product components of the vulnerability model via aircraft product structure. Using CAA second development, the detailed operations and computation methods of vulnerability analysis are integrated into CATIA software environment. Comprehensive assessment data and visual kill probability Iso-contours can also be presented, which meet the vulnerability analysis requirements of modern combat aircraft effectively. The intact vulnerability model of one hypothetical aircraft is constructed, and the effects of redundant technology to the aircraft vulnerability are assessed, which validate the engineering practicality of the method.     

基于ASP的无组件文件上传方法研究与实现

利用HTTP协议的PUT、WebDAV和RFC1867三种上传文件机制，通过操作File以及利用ADO Stream对象的BinaryRead方法读取并从中截取出所需要的文件数据，再利用ADO Stream中提供的二进制文件操作方法保存，从而实现文件的上传。论述了基于ASP的文件上传原理及实现方法，开发了一套局域网内的资料更改管理系统，已应用于研制工作中。     

Multi-aspect radar target recognition method based on scattering centers and HMMs classifiers

A hidden Markov model (HMM)-based method for recognizing aerial targets according to the sequential high-range-resolution (HRR) radar signature is presented. Its recognition features are the location information of scattering centers extracted from the HRR radar echoes by the relax algorithm. The HMM is used to characterize the spatio-temporal information of a target. Several HMMs are cascaded in a chain to model the variation in the target orientation and used as classifiers. Computer simulations with the inverse synthetic aperture radar (ISAR) data are given to demonstrate that for an open-set recognition, average class-recognition rates of 84.50% and 89.88% are achieved, respectively, under two given conditions.     

浅议西安超市存在的问题及治理对策

自1999年天津家世界家乐购物广场进驻西安以来,短短几年,西安的超市有了长足发展,但在管理模式、经营理念、员工素质、防损降耗等方面还存在一些问题。针对这些问题,提出了业态整合、人性化管理、提高员工素质、全程服务等新的发展思路和治理对策。     

HDJT企业年金初探

介绍了企业年金的起源与发展以及建立企业年金的意义和作用，对建立企业年金的原则和具体程序进行了阐述，并对HDJT公司建立企业年金的可行性和必要性进行了分析。     

对自主招生学生工作管理的研究

北京信息职业技术学院自2006年开始对软件技术专业等五个专业实行自主招生.几年来,这些"特殊"学生身上的种种表现和每一点变化都引起系院各级领导和相关部门的注意.文章就软件技术专业自主招生学生的特点,对学生管理工作提出了若干设想,力图为探索设计"面向就业"的人才培养方案提供一些帮助.     

基于Ansys某型气密接头泄露率试验台的设计

创新性的构建气密接头试验台以对某型气密接头的各参数进行测量。通过控制电机的正反转、高压舱室和大气压的压力差,完成对钢丝绳与气密接头相对往返运动、接头两端的压差等工作状况的模拟,并利用Ansys对试验舱体仿真优化,利用最佳参数进行制造,取得了实际结果。     

采样机械臂关节月表环境适应性设计

文章针对月球表面采样任务对机械臂关节防尘、耐高低温和轻量化的特殊要求,提出一种由永磁同步电机驱动、2K-H行星减速器+谐波减速器传动的关节设计方案。该方案采用电机的齿槽转矩提供关节制动力矩,并采用前馈力矩补偿控制的方法消除齿槽转矩引起的速度波动,节省了制动器的配置;通过控制减速器传动侧隙、电机定子与壳体的过盈量及密封垫片厚度,实现关节在-100~160℃高低温环境的热匹配和防尘。仿真分析和样机试验结果验证了关节设计方案可满足月表采样的月面特殊环境要求。     

基于量子海鸥算法的运载火箭回收舱段时差定位方法

火箭回收舱段的准确定位是实现运载火箭可重复使用的关键技术之一。针对运载火箭回收舱段飞行轨迹的特点,基于多站到达时间差(TDOA)无源定位原理,通过在回收舱段上加装主动辐射源设计了火箭回收舱段定位系统。将时差非线性定位方程求解问题转化为时差似然函数的极值优化问题,通过引入量子编码理论、混沌映射和遗传反向学习机制改进海鸥算法(SOA),将其用于搜索回收舱段最优定位信息。仿真结果表明:改进的量子海鸥算法在火箭回收舱段定位解算的早期收敛速度、定位精度、全局搜索能力等方面均优于传统Chan算法和标准海鸥算法。     

用于硅微加速度计检测的差分频率电路设计

微机械加速度计以其具有体积小、成本低、易于集成和批量生产的特点越来越受到人们的关注。本文针对谐振式微加速度计微弱信号的检测问题,提出了一种新的微弱信号的检测方法,并且设计了相关的差分频率检测电路,该电路简单、精度高、易于集成、抗干扰性好,具有广阔的应用前景。