基于WBS与多层次模糊综合评估的桥梁检测评估方法的研究

介绍了WBS方法在桥梁检测评估中的应用,提出了WBS方法与多层次模糊综合评估相结合的桥梁检测评估方法,并用实际工程加以了分析及验证.将WBS方法与多层次模糊综合评估相结合,使桥梁评估既便捷又科学,提高了桥梁检测评估的可靠度.     

公共交通系统营运可靠性研究

优先发展公共交通是大城市解决交通拥堵,实现城市交通可持续发展的一项重要措施,然而,公交营运水平的低下制约着公交的发展。本文借鉴可靠性理论对公共交通营运可靠性进行定义,并对公交营运时间和乘客服务可靠性分别进行了描述,据此建立起公交系统营运可靠性模型,然后采用随机模拟技术(即Monte Carlo模拟)进行求解,通过算例说明模型的可行性,最后通过分析可靠性模型得出大型活动期间改善公交营运的途径。     

水泥混凝土路面结构模糊随机可靠度设计方法研究

我国水泥混凝土路面设计经历了3个发展阶段：经验法、力学一经验法和可靠度设计法。由于荷载、环境作用和结构设计参数的随机性和模糊性，它们都将影响路面结构的可靠度水平。为了更好地发展现有路面设计理论，系统地分析了现有水泥混凝土路面设计规范，对路面结构可靠度进行了定义和讨论。采用模糊随机可靠度理论，对水泥混凝土路面结构可靠度设计方法进行了系统分析，研究提出了路面模糊随机可靠度的设计公式，讨论了各个设计变量的变异性，并结合具体设计提出了详细的步骤和思路。     

太阳能游船光伏逆变器控制系统EMC设计

从船舶环境和光伏逆变器的基本原理和功能出发,分别对太阳能游船EMC干扰源和干扰路径进行分析,通过信号滤波与保护、工艺设计和试验测试,实现高可靠性的太阳能游船光伏逆变器控制系统研究和设计,为太阳能游船的光伏逆变器控制系统研究提供基本EMC设计思路与实现技巧。     

深度模拟器液压系统仿真研究

介绍了深度模拟器总体结构及工作原理,针对深度模拟器控制系统中PID算法及其相关参数进行了仿真研究。以深度模拟器液压系统为模型,利用AMESim仿真软件工具,对整个液压系统进行了仿真分析并对系统各元器件的参数进行了优化,为深度模拟器的进一步研究提供了理论基础。     

舰艇编队信息融合中模糊C-均值算法改进研究

在分析舰艇编队信息处理融合的基础上,提出舰艇编队信息融合体系结构、模型和实现框架。针对原C-均值算法在处理数据时的不合理性,提出了改进的模拟C-均值算法,提高分类效果,满足信息融合的实时要求和可靠性要求。     

Comparing different contour methods with response-based methods for extreme ship response analysis

Environmental contours are often applied in probabilistic structural reliability analysis to identify extreme environmental conditions that may give rise to extreme loads and responses. They facilitate approximate long term analysis of critical structural responses in situations where computationally heavy and time-consuming response calculations makes full long-term analysis infeasible. The environmental contour method identifies extreme environmental conditions that are expected to give rise to extreme structural response of marine structures. The extreme responses can then be estimated by performing response calculations for environmental conditions along the contours.Response-based analysis is an alternative, where extreme value analysis is performed on the actual response rather than on the environmental conditions. For complex structures, this is often not practical due to computationally heavy response calculations. However, by establishing statistical emulators of the response, using machine learning techniques, one may obtain long time-series of the structural response and use this to estimate extreme responses.In this paper, various contour methods will be compared to response-based estimation of extreme vertical bending moment for a tanker. A response emulator based on Gaussian processes regression with adaptive sampling has been established based on response calculations from a hydrodynamic model. Long time-series of sea-state parameters such as significant wave height and wave period are used to construct N-year environmental contours and the extreme N-year response is estimated from numerical calculations for identified sea states. At the same time, the response emulator is applied on the time series to provide long time-series of structural response, in this case vertical bending moment of a tanker. Extreme value analysis is then performed directly on the responses to estimate the N-year extreme response. The results from either method will then be compared, and it is possible to evaluate the accuracy of the environmental contour method in estimating the response. Moreover, different contour methods will be compared.     

A copula-based approach for estimating the travel time reliability of urban arterial

Estimating the travel time reliability (TTR) of urban arterial is critical for real-time and reliable route guidance and provides theoretical bases and technical support for sophisticated traffic management and control. The state-of-art procedures for arterial TTR estimation usually assume that path travel time follows a certain distribution, with less consideration about segment correlations. However, the conventional approach is usually unrealistic because an important feature of urban arterial is the dependent structure of travel times on continuous segments. In this study, a copula-based approach that incorporates the stochastic characteristics of segments travel time is proposed to model arterial travel time distribution (TTD), which serves as a basis for TTR quantification. First, segments correlation is empirically analyzed and different types of copula models are examined. Then, fitting marginal distributions for segment TTD is conducted by parametric and non-parametric regression analysis, respectively. Based on the estimated parameters of the models, the best-fitting copula is determined in terms of the goodness-of-fit tests. Last, the model is examined at two study sites with AVI data and NGSIM trajectory data, respectively. The results of path TTD estimation demonstrate the advantage of the proposed copula-based approach, compared with the convolution model without capturing segments correlation and the empirical distribution fitting methods. Furthermore, when considering the segments correlation effect, it was found that the estimated path TTR is more accurate than that by the convolution model.     

基于语义挖掘的快递运输货品风险评价研究

为提高快递运输的风险监测管控能力，降低因快递货品风险导致城市安全事件发生的可 能性，本文基于语义挖掘方法将快递运输货品描述转化为风险的量化表征，为快递运输风险评价 提供可量化的客观指标依据。基于网络大数据资源提供的法院判决书数据，将物品词条与判决 结果相关联，通过隐狄利克雷分布模型挖掘物品风险主题，结合模糊均值聚类方法，实现对快递 货品语义风险的量化表征与柔性划分。与传统方法中依赖检视人员查验既定违禁品清单后的主 观判断方法不同，本文充分挖掘网络文本数据中的可迁移知识，并应用于种类繁多的快递运输货 品，有效避免人工评价造成的漏检、错检情况。研究结果表明，本文方法具有较高的准确率与较 低的误报率，获得的风险评价值不再是0或1的是非判断，有利于开展多样化、针对性的风险预警 及应对措施。     

基于模糊综合评价法的城市综合管廊结构健康评价方法研究

为解决城市综合管廊结构健康状况评估结果无法量化和指导运维的问题，通过分析模糊综合评价理论在交通隧道结构健康评价方法研究中的应用，依照类比思想，利用该理论建立城市综合管廊结构健康状况评价体系。首先，依据有关养护规定和调研结果，基于不同需求分别建立管廊结构的本体完好状况和本体结构状况评价指标体系； 其次，以交通隧道和综合管廊养护经验为基础，划分各指标的分级判定标准； 然后，采用层次分析法，计算评价指标的权重分配； 最后，采用柯西分布型隶属函数和矩阵型隶属函数确定各指标的隶属度，建立一级和二级模糊综合评价模型，赋予评价向量中各评语相应分值，将评价向量单值化，判定管廊结构健康状况。采用所提出的评价方法应用于实际工程，所得评价结果与经验评判得到的结果相同。