基于残差决策的自动飞行控制系统远程实时故障诊断

针对自动飞行控制系统结构复杂、关联部件众多,发生故障时诊断时间长,从而影响飞机运行效率的问题,提出一种基于飞机通信寻址报告系统(ACARS)的远程实时故障诊断方案。首先,分析自动飞行控制系统的故障特点,设计搭建检测滤波器;然后,利用ACARS数据链实时发送的自动飞行控制系统的关键信息进行相关部件的残差计算,并根据残差决策算法进行故障诊断及定位;最后,针对不同故障部件残差间的差异大、决策门限无法统一的缺点,提出基于二次差值的残差决策改进算法,减缓了检测对象的整体变化趋势,降低了随机噪声和干扰的影响,避免了将瞬态故障诊断为系统故障的情况。实验仿真结果表明,基于二次差值的改进残差决策算法避免了多决策门限的复杂性,在采样时间为0.1 s的情况下,故障检测所需时间大约为2 s,故障检测时间大幅降低,有效故障检测率大于90%。     

Validation of performance of real-time kinematic PPP. A possible tool for deformation monitoring

Structural failures (bridge or building collapses) and geohazards (landslides, ground subsidence or earthquakes) are worldwide problems that often lead to significant economic and loss of life. Monitoring the deformation of both natural phenomena and man-made structures is a major key to assessing structural dynamic responses. Actually, this monitoring process is under real-time demand for developing warning and alert systems.One of the most used techniques for real-time deformation monitoring is the Global Navigation Satellite System (GNSS) real-time procedure, where the relative positioning approach, using a well-known reference station, has been applied.This study was conducted to evaluate the actual quality of the real-time kinematic Precise Point Positioning (PPP) GNSS solution for deformation monitoring, where it can be concluded that a promise tool is under development and should be taken into account on actual and near future real-time deformation monitoring studies and applications.     

基于消息队列的通信系统异步传送控制仿真

传统方法对通信系统异步传送控制效果不佳,存在信号干扰及传送时间间隔较长等问题。为此引入消息队列技术,提出一种新的传送控制方法来解决以上问题。对通信系统的空时信道进行空时编码设计,实现空时信道的编码增益与分集增益;利用空时编码实现通信系统中继节点的空间分集,根据空间分集结果制订异步空时传送方案;采用消息队列技术构建通信系统异步传送控制模型,实现通信系统的异步传送控制。为了验证所提方法异步传送控制效果,设计对比实验。实验结果表明,上述方法的传送时间间隔较短,抗干扰能力强,平均分集增益高,说明所提方法更适用于通信系统的异步传送控制。     

Looking at both sides of relationship dynamics in virtual communities: A social exchange theoretical lens

This study draws on social exchange theory to investigate the relationship dynamics of the member–community dyad in virtual community settings. Using a longitudinal design and multiple measurement sources, the findings indicate that social and task communication styles have unique effects on members’ community commitment velocity, which in turn influences member gratitude and entitlement behaviors. A moderated path analysis demonstrates that the effects of social and task communication styles on community commitment velocity are both positively moderated by attachment anxiety and attachment avoidance. It also reveals that members’ level of popularity augments the influence of community commitment velocity on member entitlement behavior.     

Scheduler-based state estimation over multiple channels networks

We investigate the remote state estimation problem for networked systems over parallel noise-free communication channels. Due to limited network capabilities in practical network environments, communication schedulers are implemented at the transmit side of each subchannel to promote resource efficiency. Specifically, the processed signals are transmitted only when it is necessary to provide the real-time measurements to the remote estimator. The recursive approximate minimum mean-square error estimator is established to restore the state vector of a target plant by utilizing the scheduled transmission signals. All the information coming from the individual subchannels, even if no measurement is sent, will contribute to improve the estimation performance in an analytical form. Finally, a numerical example is given to illustrate the effectiveness of the main results.     

相互作用模型在城市规划中的运用

城市增长是未来几个世纪备受关注的问题。为了保证城市可持续发展，有必要对城市的发展进行监控，但预测城市的发展趋势需要一些空间信息的支持、卫星图像能够提供可靠的信息用来评定城市增长的不同状态，而预测未来的建设区段则更加重要。本文构建了相互作用模型（interaction models），或者更精确地说叫潜力模型（potential model），以确定城市空间的扩展方向。该模型被运用于法国斯特拉斯堡地区的分析，采用了两张遥感数据影像，一张用于模型处理，一张用于检验结果。另外，模型还运用GIS技术以提高准确度，同时还考虑到了交通网络。     

透过立面材质谈保护——汉口原租界区近代建筑立面材质保护研究

论述了立面材质在历史地段保护工程中的重要作用,从立面材质层面对原租界近代建筑较为集中的一元片区的历史建筑和街区进行了全面调研.指出在旧城改造中,大量廉价人造材料覆盖做工精细、历尽沧桑的原有建筑立面的现状,致使材质特征被抹杀,场所精神被破坏等严重后果,由此,提出立面材质的保护意义和相关建议.     

CC—Link总线及其在电梯上的应用

本文对CC—Link现场总线的发展、技术及原理进行了阐述，并对其在电梯上的应用进行介绍。最后，笔者结合实例，介绍了CC—Link总线的特点。     

试论总监在工程项目中的沟通

叙述总监在工程项目中与相关各方沟通的重要性及沟通的方式方法 ,同时结合作者本人的经验探讨如何采取措施更好的与工程项目相关各方进行沟通。     

从人体工程学来谈建筑通道设计

人类社会就是在不断改造自然物,使之为人类自身服务的过程中发展起来的,在这个改造的过程中要解决的主要问题之一就是人和环境是否相互适应的问题.通道设计应充分遵循人体工程学的原理;为建筑环境的主要功能服务,使整体设计达到完美、协调、统一的目的,对人类有较高的舒适度及很好的生命保障功能.