Energy-aware load-balaning fault-tolerant routing scheme for ad hoc sensor networks

Most routing protocols for sensor networks try to extend network lifetime by minimizing the energy consumption, but have not taken the network reliability into account. An energy-aware, load-balancing and fault-tolerant routing scheme, termed as ELFR was propsed to adapt to the harsh environment. First a network robustness model was presented. Based on this model, the route discovery phase was designed to make the sensors to construct into a hop-leveled network which is mesh structure. A cross-layer design was adopted to measure the transmission delay so as to detect the failed nodes. The routing scheme works with acknowledge （ACK） feedback mechanism to transfer control messages to avoid producing extra control overhead messages. When nodes fail, the new healthy paths will be selected locally without rerouting. Simulation results show that our scheme is much robust, and it achieves better energy efficiency, load balancing and maintains good end-to-end delay.     

Measurements of car-body lateral vibration induced by high-speed trains negotiating complex terrain sections under strong wind conditions

Assessment of the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions is very important for research into the operation safety and comfort of passengers on high-speed trains. To assess the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions, we performed a field measurement when the train passes through typical sections of complex terrain along the Lanzhou–Xinjiang high-speed railway in China. We selected the lateral vibration conditions, including the roll angle and lateral displacement of car-body gravity centre through two typical representative sections (embankment–tunnel–embankment and embankment–rectangular transition–cutting) for analysis. The results show that the severe car-swaying phenomenon occurs when the high-speed train moves through the test section, and the car-body lateral vibration characteristic is related significantly to the state of the terrain and topography along the railway. The main causes for this car-swaying phenomenon may be the transitions between different windproof structures, and the greater the scale of the transition region between different windproof structures or landform changes, the more obvious the car-swaying phenomenon becomes. The lateral vibration of the car-body is relatively steady when the train is running through terrain with minor changes in topography, such as the windbreak installed on the bridge and embankment, but the tail car sways more violently than the head car. When the vehicle runs from the windbreak installed on the embankment into the tunnel (or in the opposite direction), the tail car sways more intensely than the head car, and the head car runs relatively stable in the tunnel.     

车门铰链布置设计

车门铰链作为车门系统的一个关键部件,对车门开关舒适性和驾乘人员出入车辆方便性起到重要作用。本文主要结合自身设计工作经验,对常用车门铰链的基本布置设计方法进行研究,希望能够使大家在同类车门铰链布置设计方面的理解和掌握有所助益。     

浅析别克陆尊发动机不能启动的原因

通过对别克陆尊发动机不能启动故障的检修,以发散思维分析查找造成故障的深层次原因,以及采取彻底排除故障的有效措施,为同型号车辆的相同故障检修提供指导性经验,亦可作为汽车制造厂家技术改进的依据。     

无人机技术在长江海事监管中的应用

为了打造长江干线全方位覆盖、全天候运行、具备快速反应能力的现代化水上安全监管和应急救助体系,将无人机技术引入海事监管过程当中。分析无人机应用于海事监管的优势,并研究其应用于海事监管的可行性。拓展无人机在海事监管业务中的应用,提出长江海事无人机系统建设思路。系统的建设分为实验阶段、大规模实施阶段和网络建设和应用阶段,目标是建成水-岸-空海事立体监管系统,提升长江海事监管水平。     

航运企业的投资决策

本文分析了航运企业的成本构成和投资决策的要素，提出了根据航运市场和造船市场的关系选择投资时机的观点及分散投资风险的方法。     

长大管棚在马垭口公路隧道浅埋段施工中的应用

介绍巫奉高速公路A15合同段马垭口隧道40 m长大管棚超前支护的施工技术,包括技术参数确定、施工工艺、进度情况、质量控制等。实践证明,长大管棚超前支护技术在浅埋、软岩、黄土等不良地质隧道施工中具有非常重要的意义。     

广州地铁4号线箱梁节段预制施工技术

广州市轨道交通4号线南延段(黄阁至冲尾)(预制4标)工程,对简支梁、连续梁节段箱梁在制梁场采用短线法预制施工。简要介绍短线台座法节段箱梁预制施工主要工艺和方法。     

西康铁路增建二线太峪滑坡勘察

太峪滑坡是西康二线控制线路方案的重要工点，在勘察中运用物探、钻探等综合勘探手段，查明了太峪滑坡的特征，进行了滑坡成因分析，评价其稳定性，为地质选线提供了依据。     

重庆单轨FAS及BAS系统车站级网络集成实践

重庆单轨地下车站FAS与BAS系统进行的网络集成,既保证了车站FAS、FAS互不干扰,又使两系统共用1套管理软件,并合用1条车站至控制中心(OCC)的数据传输通道,效果良好。