Integrated airline planning: Robust update of scheduling and fleet balancing under demand uncertainty

The airline schedule planning problem is defined as the sequence of decisions that need to be made to obtain a fully operational flight schedule. Historically, the airline scheduling problem has been sequentially solved. However, there have already been many attempts in order to obtain airline schedules in an integrated way. But due to tractability issues it is nowadays impossible to determine a fully operative and optimal schedule with an integrated model which accounts for all the key airline related aspects such as competitive effects, stochastic demand figures and uncertain operating conditions. Airlines usually develop base schedules, which are obtained much time in advance to the day of operations and not accounting for all the related uncertainty. This paper proposes a mathematical model in order to update base schedules in terms of timetable and fleet assignments while considering stochastic demand figures and uncertain operating conditions, and where robust itineraries are introduced in order to ameliorate miss-connected passengers. The proposed model leads to a large-scale problem which is difficult to be solved. Therefore, a novel improved and accelerated Benders decomposition approach is proposed. The analytical work is supported with case studies involving the Spanish legacy airline, IBERIA. The presented approach shows that the number of miss-connected passengers may be reduced when robust planning is applied.     

A novel approach for the modelling of air quality dynamics in underground railway stations

Indoor air quality in subterranean train stations is a concern in many places around the globe. However, due to the specificity of each case, numerous parameters of the problem remain unknown, such as the braking discs particle emission rate, the ventilation rate of the station or the complete particle size distribution of the emitted particles. In this study the problem of modelling PM₁₀ concentration evolution in relation with train traffic is hence addressed with a particle-mass conservation model which parameters are fitted using a genetic algorithm. The parameters of the model allow to reproduce the dynamics and amplitude of four field data sets from the French and Swedish underground contexts and comply with realistic bounds in terms of emissions, deposition and ventilation rate.     

公路工程施工管理质量研究

公路工程施工管理直接关系到工程项目的质量,在施工中加强管理控制是十分必要的,结合公路工程施工管理的特点,对影响公路工程管理质量的因素进行分析,并提出具体解决对策,对类似工程施工有一定的指导意义.     

连续配筋混凝土路面的技术应用

介绍连续配筋混凝土路面的基本概念,说明我国CRCP的结构设计理论和设计方法,可为该技术在我国的推广应用提供理论支撑.     

福州轨道交通建设安全管控平台的设计与应用

福州城市轨道交通建设规模不断增大，复杂的地质、环境条件以及众多工种施工的交叉作业和人员活动，给安全生产带来挑战。针对建设全过程安全管控的具体业务关系和需求分析，梳理和固化工作岗位、职责、流程、响应、整改等安全管理的事项和要求，强化对管控过程的追溯和考核管理。研究信息平台的业务需求、平台架构、网络拓扑、功能模块、数据库设计方法和实现思路，利用Ssm框架、Quartz框架、Encache技术以及SQLServer数据库技术，设计开发基于B/S模式的城市轨道交通安全管控信息系统，应用于在建的5条线路。信息平台的应用，可实现安全管理的标准化、科学化和精细化，极大地提高管理水平和工作效率。     

上海松江区现代有轨电车规划研究

现代有轨电车因其环保、舒适、高效、低造价、高品质等特点,在国际上得到广泛应用,我国多个城市也在规划和建设之中。但是,由于其在国内尚为一种全新的交通方式,没有标准或规范予以指导,规划及设计体系不完善,有些已建项目已呈现问题。文章结合上海松江区规划背景及交通特征,阐述有轨电车示范线T1、T2线的布局规划、建设的必要性及适应性,为即将开展有轨电车规划及建设的城市提供借鉴与参考。     

BIM技术在清华珠三角公建项目施工中的应用研究

随着科技的进步及项目管理水平的提高,BIM技术应运而生。本文以清华珠三角研究院粤港澳大湾区创新基地项目为依托,从应用目标、应用前准备工作、前期策划管理、技术管理、质量安全管理、物资设备管理、进度管理、经济成本管理等方面开展BIM技术在公建项目施工中的应用研究,结果表明:使用BIM技术,使项目管理走向精细化、全面化、高效化,并提高质量标准,增加安全保障,减少项目成本,提高项目利润率;同时与AI技术相结合,使BIM技术更加具有简便性,产出更大效益。     

Residential built environment and walking activity: Empirical evidence of Jane Jacobs’ urban vitality

This study intends to empirically verify Jacobs’ urban vitality theory, which was based on the observations of her New York City neighborhood in the mid-20th century. To examine the relationship between the residential built environment and walking activity, we used telephone survey data consisting of 1823 valid samples from across Seoul, a city characterized by a high population density and a well-established public transportation system. Respondents were asked questions about their residential location, their demographic and socioeconomic characteristics, and their walking activities. This study then used geographic information systems to measure objective indicators of built environment variables within 500-meter buffer areas based on the home addresses of the respondents. Then, this study constructed multilevel regression models with walking activity as the dependent variable. Our results indicated that walking activity is associated with Jacobs’ six conditions for urban vitality, including land use mix, density, block size, building age, accessibility, and border vacuums.     

车用摇枕铸钢件浇冒口切割打磨自动化系统的设计

铸钢件毛坯浇冒口切割及打磨时存在噪音大、弧光强烈、粉尘污染严重,增加了人工操作时的劳动强度,并严重影响操作人员的身体健康。本文针对这些问题,拟以铁路车辆摇枕铸钢件浇冒口切割及打磨为例,提出了单工位打磨、流水线式多工位合作的打磨清理方案,设计了自动化打磨单元,实现机械化、自动化操作,既提高了铸件打磨清理的质量和生产率,又大大改善了工人操作条件,减轻了工人的劳动强度,达到了“以机代人”的目的,对铸钢件实现绿色化乃至智能化生产具有重要意义。     

汽车前照灯闪烁问题分析及设计优化

汽车前照灯是整车照明的重要组成,随着时代的发展,汽车前照灯的设计也越来越简单化、多样化。本文针对某车型项目阶段出现的前照灯闪烁问题,从前照灯的控制逻辑展开,分析故障产生的原因,并研究优化方案。