浮摆式波浪发电平台系泊系统设计

针对一台自行设计的浮摆式波浪发电平台的运动特点与采能方式,对其系泊系统进行设计。系泊型式为"平台—连接缆—浮筒—锚链—锚"的悬链线单点浮筒系泊。以试验海域海况参数为依据,计算系统载荷,并采用准静力分析法对系泊系统各构件进行选型设计。设计的连接缆为钢丝绳,浮筒为圆柱型钢制浮筒,锚链为二级有档锚链,作业锚为AC-14锚。经检验,设计的系统符合安全要求和平台稳定性需求。     

xPON技术在铁路视频监控系统的应用前景简

xPON作为新一代光纤接入技术,在抗干扰性、带宽特性、接入距离、维护管理等方面均具有巨大优势,将成为一种主流宽带接入技术,并在铁路视频监控系统中有很广阔的应用前景.     

深水中承台悬吊钢套箱施工

南丫大桥横跨东莞水道南丫涌，6#-10#墩处在深水中，如何高效、安全地进行承台施工，是本工程的难点之一。介绍一种既简便又经济的施工技术，在深水中悬吊钢套箱，成功解决了该技术难题。     

Weight threshold estimation of falling UAVs (Unmanned Aerial Vehicles) based on impact energy

Different weight thresholds for drone operations have been specified by regulatory agencies in different countries, without detailed backgrounds of guidelines. Therefore, this paper aims to study weight thresholds by focusing different levels of injuries caused by the impact of the drones on human head of different weights dropped at various heights. The work covers drone free drop modelling, FEM (finite element method) based impact modeling, and comparable drop impact experiments. The analyses and experiments were conducted accordingly to two individual commercially-available groups: small and large drones in weights. Two well-established indicators defining head injuries due to impact, which are known as Head Injury Criterion (HIC) and Abbreviated Injury Scale (AIS), are used in the present weight threshold study. The proposed AIS level for the weight threshold estimation has been set at AIS level 3, which indicates major skull fracture, in the further analysis through the probability of fatality. The main focus of the present work is to perform a parametric study and to present a reliable model to estimate the weight thresholds of the drone operations based on HIC and AIS. In conclusion, the results obtained and presented in this paper have demonstrated and provided a comprehensive analysis of possible direct injuries of a falling drone impacting a human head, with relevant data of impact or injury levels associated with HIC and AIS obtained for a drone with different weights falling from various heights.     

Towards a generic benchmarking platform for origin–destination flows estimation/updating algorithms: Design,demonstration and validation

Estimation/updating of Origin–Destination (OD) flows and other traffic state parameters is a classical, widely adopted procedure in transport engineering, both in off-line and in on-line contexts. Notwithstanding numerous approaches proposed in the literature, there is still room for considerable improvements, also leveraging the unprecedented opportunity offered by information and communication technologies and big data. A key issue relates to the unobservability of OD flows in real networks – except from closed highway systems – thus leading to inherent difficulties in measuring performance of OD flows estimation/updating methods and algorithms. Starting from these premises, the paper proposes a common evaluation and benchmarking framework, providing a synthetic test bed, which enables implementation and comparison of OD estimation/updating algorithms and methodologies under “standardized” conditions. The framework, implemented in a platform available to interested parties upon request, has been flexibly designed and allows comparing a variety of approaches under various settings and conditions. Specifically, the structure and the key features of the framework are presented, along with a detailed experimental design for the application of different dynamic OD flow estimation algorithms. By way of example, applications to both off-line/planning and on-line algorithms are presented, together with a demonstration of the extensibility of the presented framework to accommodate additional data sources.     

高精度随动系统的变结构控制

陀螺稳定平台控制系统是控制平台框架系统快速跟踪陀螺仪的高精度随动系统,是保证平台正常工作和精度的重要系统。用传统的PID调节器可以满足工作在系统线性区的要求。由于放大器、电机等存在饱和特性,因而在系统启动和随大的干扰产生大偏角时,系统将进入非线性区,PID调节器将难以满足稳定性的要求。滑模变结构控制器对非线性具有很好的适应性,对系统启动初始偏角没有限制要求,本文将应用变结构控制的方法对平台的控制系统进行设计。     

桥梁深水基础施工方案研究

介绍钢围堰方案、钢平台方案和钢套箱方案3种主要的桥梁深水基础施工方案,对方案的优缺点进行了研究,并给出了3种方案各自的适用情况。     

基于乘客换乘量和停车泊位的BRT站台规模研究

快速公交系统(BRT)的研究在我国尚处起步阶段,目前已有一些城市引进了BRT,为了保证公交的快速通行,对BRT站台规模的研究日益重要。首先找出快速公交站台规模的影响因素,由此结合排队论的相关知识,从站台乘客换乘量和泊位对站台规模的影响进行了深入探讨,提出了基于乘客换乘量和基于泊位的站台规模计算模型。该模型可以计算出站台的最小面积和最小长度;再以最小宽度为验算指标,当指标冲突时,结合调整原则,最终得到合理设置的站台规模。     

地铁车站站台设计

根据相关规范和工作实践,对地铁车站站台设计的有关问题作了探讨.     

模板式钢套箱水下承台施工质量问题及其改进措施

以龙王庙特大桥承台施工为背景,介绍了模板式钢套箱施工的基本工序与施工过程中发生的质量问题,从钢套箱模板受力计算、施工细部措施等方面对承台施工过程中的质量问题进行了分析并提出了相应的改进措施,总结了模板式钢套箱水下承台施工的经验。