桥梁健康监测系统中的大数据分析与研究

由于分布在桥梁上的传感器长时间连续地采集数据,传输的数据量非常大,传统的桥梁健康监测系统不能够完全应对海量监测数据,为此,提出了一种基于K线图时间片驱动的滑动窗口数据流处理模型,对传感器网络中的数据流进行快速有效地采集,并且能够减少桥梁监测的数据存储量。基于单一服务器节点的索力统计评估系统,在分析海量数据时存在计算瓶颈,利用集群的分布式并行计算,提出了基于Map/Reduce的索力并行处理模型,实验结果表明,在该模型下处理索力监测历史大数据,可以明显减少专家系统的分析评估时间。     

EVALUATION ON THE EFFECT OF A SHORT-TERM INTERVENTION OF SEXUAL/REPRODUCTIVE HEALTH EDUCATION AMONG RURAL MIDDLE SCHOOL STUDENTS

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铁道信号系统安全计算机状态监测方法

基于隐马尔科夫模型(Hidden Markov Model,HMM)提出了状态监测和故障诊断的原理与基本流程。通过观测数据的提取与降维,正常态模型训练与改进,故障态模型训练等一系列措施,实现了两模冗余安全计算机的状态监测,对正常态与时钟偏离1%～10%等7种不同条件进行监测。监测结果表明:对数似然概率均值从-228.98降至-1 385.60,健康状态不断恶化。对1号处理单元(PU1)故障状态进行仿真监测时,将PU1故障与PU1故障态、正常态、安全容错管理单元(FTSM)故障态、通信控制器(CC)故障态以及系统受扰故障态进行比较,得到对数似然概率均值分别为-161.95、-13.72、-14.13、-40.17及-35.69,证明了系统所发生的故障是因PU1所致。监测方法能够有效实现安全计算机健康状态的检测,为铁道信号安全计算机监测技术提供理论支撑。     

用新陈代谢极限学习机实现电池健康状态估算

针对因电池内部电化学反应的复杂性、算法泛化性差或可用已知数据量少导致的锂离子电池SOH估算精度下降的问题,提出使用极限学习机(ELM)构建强泛化性电池退化状态模型来描述不同电池的共性退化规律;引入新陈代谢机制来更新退化状态模型的输入数据进而实现对SOH的新陈代谢估算,在保证估算精度的同时降低对输入数据量的需求.利用两种...     

Environment–person interactions enabling walking in later life

Traditionally, theory suggests the ageing individual is strongly influenced by the environment and has difficulties in overcoming distance and space. Recently, however, theory has moved to suggest that older people possess greater agency, being more capable of selecting and mastering their environments and spaces according to their needs and preferences. This paper suggests that both opposing theories are correct for differing groups. Observations and surveys of older people (n = 365) in public space examined how far person–environment agency is present in active use of outdoor space, measured by confidence to use and explore space, in three locations (urban shopping centres, suburban residential area and an area of shared space). In all three areas, dominance of the space was associated with being male and having higher levels of reported health, confidence and higher socio-economic status. Only 11% of participants walked at least as fast as the UK department for transport guidance on crossing speeds.     

Travel mental budgeting under road toll: An investigation based on user equilibrium

With the approach of introducing the conceptions of mental account and mental budgeting into the process of travelers’ route choice, we try to identify why the usages of tolled roads are often overestimated. Assuming that every traveler sets a mental account for his/her travel to keep track of their expense and keep out-of-pocket spending under control, it addresses these questions such that “How much money can I spend on the travel?” and “What if I spend too much?”. Route tolls that exceed the budget are much more unacceptable compared to those within budget due to the non-fungibility of money between different accounts. A simple network with two nodes and two routes is analyzed firstly, the analytical solutions are obtained and the optimal road tolls supporting the user equilibrium as a system optimum are also derived. The proposed model is then extended to a generalized network. The multiclass user equilibrium conditions with travel mental budgeting are formulated into an equivalent variational inequality (VI) problem and an equivalent minimization problem. Through analyses with numerical examples, it is found that the main reason that the usages of high tolled roads are often overestimated is due to the fact that travelers with low and moderate out-of-pocket travel budget perceive a much higher travel cost than their actual cost on the high tolled roads.     

无风撑系杆拱桥健康监测系统设计

随着我国桥梁技术的不断发展以及人们对美观要求的不断提升,各种新颖桥梁被设计建造出来,针对大跨径桥梁有必要建立与其配套的健康监测系统.结合中承式无风撑系杆拱桥受力特点、振动特性、易损部位,设计监测系统硬件布设方案;该监测系统包括硬件布置、数据采集、数据传输、数据存储、状态评估以及预警信息发布.基于监测系的采集数据,可对桥...     

多传感信息融合的闸门状态监测系统研究

船闸是水运交通的重要枢纽,而闸门是其重要组成部分,一旦闸门发生故障会给航道运输带来巨大损失,因此对于闸门的状态监测十分必要.现有方法以振动监测最为常见,主要监测闸门运行时的振动情况,但该方法监测量单一,缺少振动引起的闸门形变、倾斜情况和开合状态监测.针对该问题,以有限元分析为指导,以振动监测为基础,研制了一种多传感融合...     

增强海员健康意识 保证海上航行安全

在研究WHO的健康的定义和STCW 95公约对于海员健康要求的基础上,提出了增强海员健康意识,提高海员身体素质是保证海上航行和人命财产安全的重要条件之一。     

Towards a driver fatigue test based on the saccadic main sequence: A partial validation by subjective report data

Developing a valid measurement of mental fatigue remains a big challenge and would be beneficial for various application areas, such as the improvement of road traffic safety. In the present study we examined influences of mental fatigue on the dynamics of saccadic eye movements. Based on previous findings, we propose that among amplitude and duration of saccades, the peak velocity of saccadic eye movements is particularly sensitive to changes in mental fatigue. Ten participants completed a fixation task before and after 2 h of driving in a virtual simulation environment as well as after a rest break of fifteen minutes. Driving and rest break were assumed to directly influence the level of mental fatigue and were evaluated using subjective ratings and eye movement indices. According to the subjective ratings, mental fatigue was highest after driving but decreased after the rest break. The peak velocity of saccadic eye movements decreased after driving while the duration of saccades increased, but no effects of the rest break were observed in the saccade parameters. We conclude that saccadic eye movement parameters—particularly the peak velocity—are sensitive indicators for mental fatigue. According to these findings, the peak velocity analysis represents a valid on-line measure for the detection of mental fatigue, providing the basis for the development of new vigilance screening tools to prevent accidents in several application domains.