超早强修补水泥混凝土早强机理研究

通过室内试验测试并分析了修补混凝土强度增长、收缩特性、新旧混凝土粘结强度等技术性能,并采用热重分析探讨了混凝土早强机理。结果表明,超早强系列修补混凝土能够满足6h通车要求,并且具有早期强度高、后期强度增长稳定无衰减、干缩及温缩性好、新旧断面粘结强度高等优点;差热分析表明,修补剂的加入减少了氢氧化钙晶体数量,提高了修补混凝土的早期强度。最终试验路的4年成功应用验证了室内研究成果。     

遗传算法在区段站到发线的应用研究

为解决车站到发线的合理运用问题，采用遗传算建立了到发线运用的染色体结构和适应度函数，对这种复杂的非线性组合优化问题进行了仿真。     

基于交易费用的物流运作模式研究

从交易费用理论及物流运作模式着手,探讨了市场采购、物流自营,物流外包与物流内包的适应环境及运作对象。即:对于一般的物流活动应该从市场上进行采购,对于集成化的物流服务应该采用外部外包,当第三方物流市场走向垄断时,要积极寻求物流内包。     

新疆公路三级区划中环境参数的提出

自然环境条件对公路工程的影响，主要体现在路线选取、路基强度和稳定性、路面稳定性和耐久性、公路主要自然病害(包括冻融、翻浆、雪害、风沙害、崩塌、滑坡和地震灾害等)、施工条件和养护运营环境等5个方面，分析自然条件和公路工程的关系，提出公路区划中地质地貌环境参数和水热状况环境参数。阐述了环境参数的提出过程，为新疆公路自然区划三级区的划分提供依据。     

浅谈FAS双中心建设及设备维护

重点分析了西安局集团公司由2K数调主系统组网更新改造为FAS双中心网络的建设方法,并根据日常维护经验,列举了调度台通道故障处理、FASB简易故障判断及计表倒换试验、FASA和FASB系统与MSC之间的业务故障处理等.     

Life cycle emissions and cost model for urban light duty vehicles

The growth of vehicle sales and use internationally requires the consumption of significant quantities of energy and materials, and contributes to the deterioration of air-quality and climate conditions. Advanced propulsion systems and electric drive vehicles have substantially different characteristics and impacts. They require life cycle assessments and detailed comparisons with gasoline powered vehicles which, in turn, should lead to critical updates of traditional models and assumptions. For a comprehensive comparison of advanced and traditional light duty vehicles, a model is developed that integrates external costs, including emissions and time losses, with societal and consumer life cycle costs. Life cycle emissions and time losses are converted into costs for seven urban light duty vehicles. The results, which are based on vehicle technology characteristics and transportation impacts on environment, facilitate vehicle comparisons and support policy making in transportation. Substantially, more sustainable urban transportation can be achieved in the short-term by promoting policies that increase vehicle occupancy; in the intermediate-term by increasing the share of hybrid vehicles in the car market and in the long-term by the widespread use of electric vehicles. A sensitivity-analysis of life cost results revealed that vehicle costs change significantly for different geographical areas depending on vehicle taxation, pricing of gasoline, electric power and pollution. Current practices in carbon and air quality pricing favor oil and coal based technologies. However, increasing the cost of electricity from coal and other fossil fuels would increase the variable cost for electric vehicles, and tend to favor the variable cost of hybrid vehicles.     

基于虚拟化云技术的路局中心地震预警监测系统方案及联动研究

通过研究铁路地震预警监测系统现状和建设趋势,从资源共享、重复性建设、地震联动触发信号系统停车、牵引供电系统断电等多角度分析存在的问题,结合实际需求,提出铁路局中心系统采用虚拟化云技术的建设思路,并提出地震预警监测系统通过路局中心系统与信号RBC、牵引供电中心接口的联动触发策略。文中论述了采用虚拟化云技术搭建的地震预警监测铁路局中心系统功能、系统构成、硬件配置,从而解决各条铁路接入路局中心增加大量服务器等所带来的资源浪费严重、重复性建设等问题,为建设项目节省投资;阐述了通过路局中心系统与信号RBC、牵引供电中心接口的联动触发方案,为安全提供保障的同时尽可能节省建设投资和维护成本,更好地为铁路安全保驾护航。     

一种基于动态分析的突变和异常波动预警方法

针对模拟量的突变和异常波动预警,给出一种基于动态分析的、可以应用于各种模拟量的统一预警方法,该方法已被应用于CSM-TH型集中监测程序和智能分析系统中,在多条线700余站现场运行的7年中,收到良好效果,得到用户认可。     

Optimal bus fleet management strategy for emissions reduction

Transportation is a major cause for environmental degradation via exhaust emissions. For many transit-oriented metropolitan areas, bus trips often constitute a sizeable mode share. Managing the bus fleet, in particular updating buses to comply with the newer emissions standards, therefore, can have a substantial impact on transportation-induced air quality. This paper presents the approach of remaining life additional benefit–cost (RLABC) analysis for maximising the total net benefit by either early-retiring or retrofitting the current bus fleet within their lifespans. By referring to the net benefits for different bus types estimated by RLABC analysis, the most beneficial management scheme for the current bus fleet can be identified. Optimal bus fleet management (BFM) models based on the RLABC analysis for the operator and the government are developed. Then a government subsidy plan is produced to achieve win–win solutions, which will offer efficient and flexible management schemes. To illustrate the approach, the largest bus company in Hong Kong, which carries more than 23% of the total trips in Hong Kong, is taken as a case study example. Instead of adopting a fixed retirement plan, such as replacing buses at the age of 17 as is currently practised, the proposed method develops an optimal BFM scheme that progressively phases out buses or retrofits them. This study produces promising results to demonstrate the large benefit of this approach for optimal bus fleet management.     

Socially optimal electric driving range of plug-in hybrid electric vehicles

This study determines the optimal electric driving range of plug-in hybrid electric vehicles (PHEVs) that minimizes the daily cost borne by the society when using this technology. An optimization framework is developed and applied to datasets representing the US market. Results indicate that the optimal range is 16 miles with an average social cost of $3.19 per day when exclusively charging at home, compared to $3.27 per day of driving a conventional vehicle. The optimal range is found to be sensitive to the cost of battery packs and the price of gasoline. When workplace charging is available, the optimal electric driving range surprisingly increases from 16 to 22 miles, as larger batteries would allow drivers to better take advantage of the charging opportunities to achieve longer electrified travel distances, yielding social cost savings. If workplace charging is available, the optimal density is to deploy a workplace charger for every 3.66 vehicles. Moreover, the diversification of the battery size, i.e., introducing a pair and triple of electric driving ranges to the market, could further decrease the average societal cost per PHEV by 7.45% and 11.5% respectively.