挠度法求残余预应力的试验研究

在役预应力构件的残余预应力是反映构件使用安全状况和承载力的参数,用各种规范的设计公式计算残余预应力都有误差。挠度法的现场检测可以求出在役构件的残余预应力,步骤是测量挠度,求出刚度,然后代入残余预应力与刚度的关系式即可计算出残余预应力。文中列出了测量挠度的方法和步骤,刚度的计算也有详细的过程,还给出了试验构件的残余预应力与刚度的关系式。     

VBA在Excel水文数据处理中的应用研究

文中在对基于VBA在Excel水文数据处理的基础上,对水文数据的处理过程、成果数据格式及大量报表的合理统计进行了阐述,重点对VBA与Excel的交互、文件与文件数据的交互、数据的流程化管理技术做了探讨。实践表明,VBA在Excel中的开发可以对海量水文数据进行处理,在处理过程中公共参数的设置都可自动化完成,使处理速度大大地提高。     

日照港船舶引航系统的设计与应用

根据日照港的实际情况,综合应用高精度GPS定位技术、电子海图显示与信息系统、图像处理技术、船舶自动识别技术、信息融合技术、数据库管理系统等先进技术设计并实现了船舶引航系统,介绍了系统的主要结构、功能及技术特点。实践表明,该系统能够满足船舶引航需要,保障船舶航行安全。     

数字地下空间与工程的空间分析与知识发现

建立完善的空间数据分析理论和方法体系,集成先进的空间数据分析工具,增强数字地下空间与工程的空间分析能力,使数据型数字地下空间与工程上升为分析型信息系统,是数字地下空间与工程技术与应用的发展目标和趋势。首先论述数字地下空间与工程特有的空间分析功能,如三维图形剖切、实体切割、管线碰撞分析、三维最小距离、对象属性查询等;然后论述数据分析领域迅速发展的新技术——数据挖掘与知识发现。     

高原公路水土流失预测

以香日德-花石峡高原项目区土壤侵蚀现状为例,结合3种土壤侵蚀的特点,按照水土保持技术规范,提出分区、分类的高原公路水土流失预测方法,并详细分析预测结果,提出相应的监测和治理建议.     

A time-dependent freight tour synthesis model

This paper introduces a model of urban freight demand that seeks to estimate tour flows from secondary data sources e.g., traffic counts, to bypass the need for expensive surveys. The model discussed in this paper, referred as Freight Tour Synthesis (FTS), enhances current techniques by incorporating the time-dependent tour-based behavior of freight vehicles, and the decision maker’s (e.g., metropolitan planning agency planner) preferences for different sources of information. The model, based on entropy maximization theory, estimates the most likely set of tour flows, given a set of freight trip generation estimates, a set of traffic counts per time interval, and total freight transportation cost in the network. The type of inputs used allows the assessment of changes in infrastructure, policy and land use. The ability of the model to replicate actual values is assessed using the Denver Region (CO) as a case study.     

基于细-宏观数据交互的桥梁水毁数值仿真

为精细化探究桥梁水毁倒塌机理，基于计算流体力学与泥沙动力学数值仿真，得到桥梁冲刷形态演变与波流力时程数据，构建桥梁水毁全过程的连续倒塌数值模型；通过开发细-宏观数据交互接口，将冲刷所致边界条件改变与波流力对桥梁结构作用效应实时传递至结构域桥梁连续倒塌数值模型，高精度连续仿真冲刷发展与波流力作用下桥梁水毁全程力学响应与结构形态演化；最后，通过河源东江大桥倒塌案例分析，验证该仿真方法与数据交互接口的正确性和有效性。结果表明：河源东江大桥连续倒塌可能由冲刷掏空基础后倾斜、拱脚薄弱节点失效以及非制动墩承受不平衡水平推力所致；所提出的仿真方法可实现冲刷仿真、波流力计算与结构倒塌分析的同步交互实施，可为从水文源头探究桥梁水毁失效机理与倒塌模式提供精准高效的分析工具，为桥梁抗水设计、评估以及未来规范修订提供理论基础与技术手段。     

Myopic loss aversion in the response of electric vehicle owners to the scheduling and pricing of vehicle charging

Upward expectations of future electric vehicle (EV) growth pose the question about the future load on the electricity grid. While existing literature on EV charging demand management has focused on technical aspects and considered EV-owners as utility maximizers, this study proposes a behavioural model incorporating psychological aspects relevant to EV-owners facing charging decisions and interacting with the supplier. The behavioural model represents utility maximization under myopic loss aversion (MLA) within an ultimatum game (UG) framework where the two players are the EV-owner and the electricity supplier. Experimental economics allowed testing the validity of the behavioural model by designing three experiments where a potential EV-owner faces three decisions (i.e., to postpone EV charging to off-peak periods for a discount proposed by the supplier, the amount of discount to request for off-peak charging at times decided by the supplier, and the amount of discount to accept for supplier-controlled charging) under two contract durations (i.e., short-term, long-term). Findings from the experiments show that indeed potential EV-owners perform charging decisions while being affected by MLA resulting from monetary considerations and the UG participation, and that presenting long-term contracts help potential EV-owners to curtail MLA behaviour and minimise cost even though the assumption of utility maximization is violated.     

Implausible OECD motor vehicle travel data

To assess the fuel efficiency of motor vehicles in a given country, an estimate of kilometers traveled is required. Examination of kilometers per liter among countries contributing data to OECD revealed implausible results for several. Also kilometers per vehicle were anomalous. The kilometers per vehicle based on a stratified random sample of U.S. travel varied substantially from the numbers reported by OECD during 2000–2014. OECD motor vehicle travel data are unusable.