First results of MWC SAS3 electromagnetic wave experiment on board of the Chibis-M satellite

The main goals of the Chibis-M mission are the testing of a new micro-satellite technology, the study of new physical processes related to lightning activity and the verification of possible monitoring techniques of Space Weather phenomena. In frames of the Chibis-M mission an electromagnetic wave complex MWC is installed on board of the satellite composed of electromagnetic sensors and SAS3 measuring unit. The obtained data show that the scientific instrumentation operates properly and produces interesting information. Here we present the first results of the first year of operation of the MWC in the ELF–VLF bands in different operation modes. An important conclusion is that basing on the experience of the first year it is possible to realize an effective and reliable Space Weather monitoring system using micro-satellites and simultaneously operating ground support equipments.     

航空发动机地面监控站开发标准初探

文章对国外发动机状态监控地面站的相关标准进行了深入分析,在此基础上构建了国内航空发动机地面监控站开发标准的框架,并给出了标准的主体内容以及相关标准体系建设的一些建议。     

计算机局域网安全隐患及防护

通过阐述目前的网络安全现状,分析可能存在的网络安全隐患,介绍现有比较成熟的安全技术,从而探讨保障企业网络安全的技术措施.     

核统计分析和监测方法处理多模式批处理过程

提出了一种解决批处理过程多种工作模式故障检测问题的方法。该方法从多种工作模式中提取各个模式相类似的信息,解决了该工作模式下故障检测建模问题;将核函数应用到算法中,利用核技术提高算法处理非线性数据故障检测的能力;将在每种工作模式下的数学模型进行分解,将反映相似信息和各个模式不同的信息进行分离,并分别建立故障检测模型,通过分析可以辨别出当前所处的工作模式,并且有效地检测故障的发生。     

航空发动机健康评估技术综述

健康评估技术是航空发动机健康管理的关键技术之一。详细阐述了航空发动机健康评估的研究内容,重点分析了发动机气路性能、结构以及机械系统健康评估的特点,并指出了开展航空发动机健康评估关键技术研究的重要性。     

Monitoring coastal sea level using reflected GNSS signals

A continuous monitoring of coastal sea level changes is important for human society since it is predicted that up to 332 million people in coastal and low-lying areas will be directly affected by flooding from sea level rise by the end of the 21st century. The traditional way to observe sea level is using tide gauges that give measurements relative to the Earth’s crust. However, in order to improve the understanding of the sea level change processes it is necessary to separate the measurements into land surface height changes and sea surface height changes. These measurements should then be relative to a global reference frame. This can be done with satellite techniques, and thus a GNSS-based tide gauge is proposed. The GNSS-based tide gauge makes use of both GNSS signals that are directly received and GNSS signals that are reflected from the sea surface. An experimental installation at the Onsala Space Observatory (OSO) shows that the reflected GNSS signals have only about 3 dB less signal-to-noise-ratio than the directly received GNSS signals. Furthermore, a comparison of local sea level observations from the GNSS-based tide gauge with two stilling well gauges, located approximately 18 and 33 km away from OSO, gives a pairwise root-mean-square agreement on the order of 4 cm. This indicates that the GNSS-based tide gauge gives valuable results for sea level monitoring.     

民用飞机短舱防冰系统冻雾天试验方法研究

民航规章25部1093(b)(2)条款要求短舱防冰系统在冻雾天环境中性能满足要求,通过构建开放式结冰条件模拟装置,对民用飞机短舱防冰系统在特定的地面冻雾条件下的性能进行了验证,试验对象是装机后的短舱防冰系统,在真实的飞机发动机运转条件下进行适航验证试验,表明短舱防冰系统对民航25部适航规章1093(b)(2)条款的符合性,详细给出了民用飞机短舱防冰系统地面冻雾天试验的方法。该试验方法成功在某型飞机上实施,试验方案科学合理,试验方法可以为其他型号飞机地面冻雾天试验提供参考。     

具有光纤神经系统的新颖复合材料结构的发展及展望

本文综合介绍了近年来国外迅速发展的具有光纤神经系统的新颖复合材料结构的研究成果及发展趋势。提出了埋设于复合材料内部的光纤系统将成为未来飞行器结构的“神经网络系统”而使结构成为“智能结构”等新概念。文章较详细地阐述了这种新颖结构在制造和使用过程中在应变、变形、固化、损伤、疲劳等检测方面的具体应用及发展趋势。     

基于最小不可识别损伤模型的传感器优化布置

提出了一种以不可识别损伤最小为目标的传感器优化布置方法。该方法在某种损伤情况下,建立结构的损伤模型,得到任意传感器潜在位置处的预测效应值,将使不可识别损伤模型数目减少到最小的布设方案做为最优方案。考虑到在求解最小不可识别损伤模型的个数的过程中计算量巨大,针对最小不可识别损伤模型个数的求解,编制了相应的优化算法。算例分析验证了此方法原理明确,操作简单,实用性较强。     

高级接收机自主完好性监视的可用性预测

高级接收机自主完好性监测(ARAIM)是单频RAIM的扩展。基于对垂直保护限值(VPL)和有效监视门限(EMT)的分析,给出了垂直方向ARAIM的VPL实时和预测算法;对LPV-200进近,从单星座ARAIM的可用性出发,研究了双星座、多故障情况下ARAIM的可用性;对世界范围内ARAIM的可用性进行仿真,给出仿真统计,并对中国西部航路区域ARAIM的可用性进行仿真,结果表明,在双星座双频情况下,可用性设置为99.9%时ARAIM的算法覆盖率可达100%,完全满足LPV-200进近对完好性的要求。