Robustness analysis metrics for worldwide airport network: A comprehensive study

Robustness of transportation networks is one of the major challenges of the 21st century. This paper investigates the resilience of global air transportation from a complex network point of view, with focus on attacking strategies in the airport network, i.e., to remove airports from the sys-tem and see what could affect the air traffic system from a passenger's perspective. Specifically, we identify commonalities and differences between several robustness measures and attacking strate-gies, proposing a novel notion of functional robustness: unaffected passengers with rerouting. We apply twelve attacking strategies to the worldwide airport network with three weights, and eval-uate three robustness measures. We find that degree and Bonacich based attacks harm passenger weighted network most. Our evaluation is geared toward a unified view on air transportation net-work attack and serves as a foundation on how to develop effective mitigation strategies.     

Operational modal analysis via image based technique of very flexible space structures

Vibrations represent one of the most important topics of the engineering design relevant to flexible structures. The importance of this problem increases when a very flexible system is considered, and this is often the case of space structures. In order to identify the modal characteristics, in terms of natural frequencies and relevant modal parameters, ground tests are performed. However, these parameters could vary due to the operative conditions of the system. In order to continuously monitor the modal characteristics during the satellite lifetime, an operational modal analysis is mandatory. This kind of analysis is usually performed by using classical accelerometers or strain gauges and by properly analyzing the acquired output. In this paper a different approach for the vibrations data acquisition will be performed via image-based technique. In order to simulate a flexible satellite, a free flying platform is used; the problem is furthermore complicated by the fact that the overall system, constituted by a highly rigid bus and very flexible panels, must necessarily be modeled as a multibody system. In the experimental campaign, the camera, placed on the bus, will be used to identify the eigenfrequencies of the vibrating structure; in this case aluminum thin plates simulate very flexible solar panels. The structure is excited by a hammer or studied during a fast attitude maneuver. The results of the experimental activity will be investigated and compared with respect to the numerical simulation obtained via a FEM-multibody software and the relevant results will be proposed and discussed.     

变结构控制在导弹总线网络控制中的应用研究

随着导弹数字控制技术和网络通信技术的发展,数据总线传输方案越来越受到重视.以数据总线为核心的导弹总线网络控制系统能够有效克服传统通信网络的弊端,改善系统性能,然而由于信息传输分时复用通信网络,系统延时是不可避免的.本文利用接收缓冲区,将时变延时转变为固定延时,并在此基础上,对导弹总线网络控制系统提出滑模预估控制器设计方法.仿真结果表明,这种设计方法是有效的.     

综合火力／飞行控制系统的一种自调整因子模糊控制

研究了综合火力／飞行控制系统（ＩＦＦＣＳ）模糊控制器因子的自调整问题。本文用降半凸函数和指数函数来描述量化因子及比例因子与误差ｅ的关系，提出了自调整因子模糊控制的一种设计方法，并进行了计算机仿真验证。仿真结果表明，这一方法的控制效果是较满意的。     

反馈系统的φ-稳定性、无源性及输出解的性质

本文在(?)-稳定性条件下研究了反馈系统的无源性和输出解的性质,给出了反馈系统无源性及输出解的稳定性,连续性和唯一性的新判据。     

Max＋PlusⅡ结合Matlab对数字系统进行联合设计与仿真

介绍一种Max PlusⅡ结合Matlab对数字系统进行联合设计与仿真的方法，这种方法通过Matlab来完成数字系统的原理方案仿真、模块设计和系统必要参数获取；通过比较Max Plus与Matlab的仿真结果差异来实现硬件模块的功能验证、模块之间时序关系的调整和系统功能的直观验证；最后以高速数字解调器载波恢复部分的设计为例讨论了该方法的具体应用。     

非线性飞行稳定性研究的新综合方法

本文提出“分歧和突变理论-时间历程-龙格库塔灵敏度分析”的综合方法,用其研究作为非线性系统的飞机稳定性。该方法利用分歧理论来确定飞机的全局稳定性,并由平衡面找出应予检验的平衡点,对这些平衡点,计算状态参数的时间历程,由此确定飞机运动的性质。最后,利用龙格-库塔灵敏度分析方法来研究动稳定性随时间的变化,由此可以解析地求得任意瞬间影响飞行稳定性的空气动力项,结构项及组合项。 利用上述方法所得到的有关稳定性的信息是全面的,它对飞机的操稳设计有重要参考价值。     

一种期刊管理自动化系统（PMAS）的模式

论述了期刊管理自动化的重要性，讨论了对期刊实行自动化管理的具体内容，其中包括期刊管理，期刊服务。文中还提出了组成这一自动化系统的模块化结构，最后探讨了采用微机网络实现其自动化的可能性。     

非均匀流场中燃油浓度测量的试验技术

本文设计了在非均匀流场中,能同时测量其速度分布、浓度分布和温度分布的取样感头,建立了相应的测试系统,分析讨论了该系统的测量精度及其影响因素。在常温和高温气流作用下,测量了非均匀流场中燃油浓度分布、速度分布及温度分布。燃油浓度在常温时误差在±10％以内,高温时误差在±6％以内。     

CCSDS-RS(255,223)码高速译码器的硬件实现研究

研究了空间通信用高速Reed-Solomon(255,223)码硬判决译码器的FPGA实现方法,提出一种新的纠错算法实现结构以最大程度提高译码器性能。设计中采用RiBM算法求解关键方程,并通过应用高速比特并行乘法器以及流水线和并行处理方法提高译码通过率。综合和测试验证结果显示,该译码器译码通过速率为1.7Gbit/s,译码延迟为296个时钟周期,优于目前同类型的RS译码器性能指标。