Development of a subway operation incident delay model using accelerated failure time approaches

This study aims to develop a subway operational incident delay model using the parametric accelerated time failure (AFT) approach. Six parametric AFT models including the log-logistic, lognormal and Weibull models, with fixed and random parameters are built based on the Hong Kong subway operation incident data from 2005 to 2012, respectively. In addition, the Weibull model with gamma heterogeneity is also considered to compare the model performance. The goodness-of-fit test results show that the log-logistic AFT model with random parameters is most suitable for estimating the subway incident delay. First, the results show that a longer subway operation incident delay is highly correlated with the following factors: power cable failure, signal cable failure, turnout communication disruption and crashes involving a casualty. Vehicle failure makes the least impact on the increment of subway operation incident delay. According to these results, several possible measures, such as the use of short-distance and wireless communication technology (e.g., Wifi and Zigbee) are suggested to shorten the delay caused by subway operation incidents. Finally, the temporal transferability test results show that the developed log-logistic AFT model with random parameters is stable over time.     

计算机网络安全应急响应技术的分析与研究

结合实际工作经验和研究成果,在分析安全应急响应技术发展动态的基础上,对网络入侵检测、事件隔离与应急恢复、取证、网络陷阱及诱骗等应急响应关键技术进行了分析和研究。构建了一个网络安全应急响应系统,并对系统的工作机制进行了分析。     

天津轻轨应急预案管理系统研究与设计

应急预案是描述应急响应事件处置的领域知识,是应急管理系统的基础,应急预案数字化是解决计算机理解和识别预案问题。通过对天津轻轨应急预案文本系统分析和研究,以重用ABC本体模型和基于工作流等技术基础上,实现应急预案本体,并设计出天津轻轨应急预案管理系统,以提高天津轻轨突发事件的应急处置能力,更好地保障城市轨道交通的安全运营。     

Dynamic probabilistic analysis of accidents in construction projects by combining precursor data and expert judgments

Construction accident occurrences are essentially rare, stochastic, and dynamic. This study proposes a method for accident prediction that fully captures these natures based on historical data and prior knowledge. The method utilizes the relatively high occurrence frequency of precursor events and the dependency between precursors and accidents. The modeling approach consists of three steps: (1) characterize the stochastic occurrences of precursor events over time based on precursor data; (2) estimate the failure rate of the Poisson model which is assumed to be a prior distribution of accident occurrences; and (3) elicit the expert knowledge about the stochastic dependency between near miss occurrences and accident occurrences. A copula-based Markov model is used to develop the time series model of precursors while a copula-based protocol is proposed to aid expert judgment elicitation and quantification. The probability of accident occurrence is then dynamically updated according to the observed historical near miss numbers. The proposed method is applied to a metro construction project. A five-year long near miss data were collected and used as accident precursor data, while three experts were invited to provide relevant information. The developed accident model is used to predict the accident-prone periods, which are consistent with the months that the observed near miss occurrence frequency deviates significantly from normality. Thus, the model can be used to support the planning of necessary safety improvement programs before the accident risk increased.     

Overcoming organizational challenges to secure knowledge management

Incident management systems have the potential to improve security dramatically but often experience problems stemming from organizational, interpersonal and social constraints that limit their effectiveness. These limits may cause underreporting of incidents, leading to erroneous perceptions of the actual safety and security situation of the organization. The true security situation may be better understood and underreporting may be reduced if underlying systemic issues surrounding security incident management are taken into account. A dynamic simulation, based on the parallel experience of industrial incident management systems, illustrates the cumulative effects of rewards, learning, and retributions on the fate of a hypothetical knowledge management system designed to collect information about events and incidents. Simulation studies are part of an ongoing research project to develop sustainable knowledge and knowledge transfer tools that support the development of a security culture.

支持计算机取证的入侵检测系统的设计与实现

首先分析了入侵检测和计算机取证的概念,然后给出了一个支持计算机取证的网络入侵检测系统的设计,最后对该系统的各关键模块做了简单的介绍。     

对应急响应的思考

本文先介绍应急响应的一般流程,然后着重介绍一种突发事件的定义方法,并由此寻求事件发生后的解决思路和指导思想,探讨一些解决方法。     

基于ITIL的IT服务管理系统的应用

良好的IT服务管理,使组织提升信息系统的管理效率和质量以满足变化的业务需要。IT基础架构库(ITIL)经过二十余年的改进和发展,已经演变为实施IT服务管理的最佳框架。然而组织在建立和实施IT服务管理系统时,在流程划分和模块实施等方面仍然存在诸多混淆。文章在总结ITIL和IT服务管理的框架、核心流程以及实施的基础上,以某广电公司基于ITIL的IT服务管理项目为案例,对IT服务管理的系统逻辑框架、工作流程以及事件管理这一关键流程的建立和实施进行了研究。     

电磁波入射角对小型机载天线罩透波率的影响测试

机载天线罩良好的透波率是保证天线系统高效工作重要因素,透波率的除了受天线罩本身状况影响外,还与电磁波的方向、频率、极化等因素有关。为解决天线罩透波率测试系统构建复杂、实现困难、测试误差大等问题,构建了一种天线罩透波率测试系统,并对不同电磁波频率、入射角下天线罩透波率进行测试,通过对平面螺旋天线罩的实测表明：低频段不同的入射角对天线罩透波率造成的影响较小,高频段大入射角时对透波率影响较大。     

车辆异常行为智能识别系统在高速公路事故处理上的应用

全面分析了车辆异常行为的识别及交通流参数采集处理方法,提出构建具备二级报警机制的交通事件自动识别系统框架模型.该系统可充分利用高速公路目前已有的监测设备作为系统数据采集的前端设备,提高交通事件检测的准确性和可靠性,减少二次事故的发生.