HDA中的工程方法学原则

HDA(Hierarchical Development Architecture, 层次开发框架)是一个AO(Agent Oriented,面向Agent)方法定制的框架,用户可以在此框架的基础上针对具体项目应用,开发出所需要的AO方法.描述了如何在方法工程学指导下,将现有AO方法中的元模型提取出来,在HDA中组合成一种适用的新方法.     

基于危险模式的无线传感器网络IDS模型

网络安全是无线传感器网络需要解决的重要问题之一,构建基于传感器网络的入侵检测系统是其中重要的技术.简要阐述了基于人工免疫模型及危险模式的入侵检测系统的机理,提出了一种基于危险模式理论的无线传感器网络的入侵检测系统体系结构,并对该模型的特点进行了分析,为进一步深入的研究提出了设想.     

超低比转速离心泵内流场计算及分析

运用FLUENT流体计算软件及GAMBIT前处理软件,采用三维k-ε双模型方程计算了一台高速超低比转速离心泵的内部流场。计算区域为从诱导轮进口到蜗壳出口的整个流场,通过计算得到了泵内流场的流动规律,并结合传统的泵水力估算方法,估算了泵的扬程、轴功率及效率,最后对该高速超低比转速离心泵进行了水力验证试验。验证结果表明所采用的计算方法可行。     

添加微量铜对FeCoNbSiB合金非晶形成能力及磁性的影响

采用工业用硼铁为主要原料制备一种FeCoNbSiBCu大块非晶合金.采用差示扫描量热分析、X射线衍射分析、扫描电镜及能谱分析对合金的非晶形成能力进行研究.结果表明,通过添加微量Cu可以显著提高FeCoNbSiB合金玻璃形成能力,当添加Cu的原子比含量为0.5at%～0.7at%时,合金的非晶形成能力明显提高.采用振动样品磁强计对铸态样品的软磁性能进行研究.结果表明,当Cu的加入量为0.5at%时,非晶合金的软磁性能得到提高.     

PW-1模料的性能研究

研究了有机高分子聚合物PX为添加剂的PW-1模料,在不同的压注温度下的性能:如抗弯强度、线收缩率、热稳定性,也测定了其熔点和灰分作为参考。     

脉冲雷达频率稳定度问题的仿真研究

本文用蒙特卡罗计算机仿真法研究振荡信号频率起伏对脉冲雷达性能的影响。由于现代脉冲雷达存在明显的混叠效应,和由放大链引入附加噪声等情况,使其仿真方法要比连续波时复杂得多。本文提出的五阶ARMA滤波以及间隔取数据的办法可较好地解放混叠效应的仿真问题。文末举脉冲多普勒雷达为例,介绍仿习具体步骤和仿真结果。     

辊弯成形仿真分析与参数优化(英文)

辊弯成形工艺是一种在常温下将平板金属材料通过连续转动的成形辊成形为所需截面的加工方法.本文通过有限元模型建立了一套避免重大产品质量缺陷的设计方法.通过对真实产品的仿真,在设计中考虑了两个辊弯成形主要缺陷,即边波和回弹.设计结果表明,该设计方法能够有效地控制这两大质量问题.     

On the origin of satellite swarms

For a species to develop in nature basically two things are needed: an enabling technology and a “niche”. In spacecraft design the story is the same. Both a suitable technology and a niche application need to be there before a new generation of spacecraft can be developed. In the last century two technologies have emerged which had and still have a huge impact on the development of technical systems: Micro-Electronics (ME) and Micro-Systems Technology (MST). Many different terrestrial systems have changed dramatically since the introduction of ME and MST and many new systems have emerged. In the same period many nano-satellites have been built and launched and shown that they can perform in space. Still it is not clear what the specific role of these small satellites will be. Where will they go? What will they do? In this paper the authors will try to answer these questions and will refer to the OLFAR space born radio telescope as one of the niche applications for a nano-satellite swarm.     

Forest Fire Monitoring Methods and Applications of HJ-1A/B Satellites

Forest fire is a frequent natural disaster and spreads randomly across forestland.It can cause great damage and loss to forest resources,the ecological system and people’s life and property. It is necessary to monitor and detect forest fire at the beginning.     

Design and Experiments of Model-free Compound Controller of Flight Simulator

A model-free compound controller design method is proposed to achieve the wide frequency bandwidth requirement of flight simulators. The method based on quantitative feedback theory, acquires system uncertainty under different working conditions through closed-loop identification with power spectrum estimation. Then in controller designing, it makes a tradeoff between the strict requirements for magnitude-frequency characteristics and those for phase-frequency characteristics of flight simulators, by converting the indices of magnitude-frequency characteristics of flight simulators into quantitative feedback theory-based tracking specification bounds and using feedforward controller to attain the required phase-frequency characteristics. Simulation and experimental results indicate that, when used to design inner frame controller of flight simulator, the proposed method can fulfill the requirements for wide frequency bandwidth indices. Compared with other controller design methods, it has the property of model-free and transparency.