A probabilistic framework for weather-based rerouting and delay estimations within an Airspace Planning model

In this paper, we develop a novel severe weather-modeling paradigm to be applied within the context of a large-scale Airspace Planning and collaborative decision-making model in order to reroute flights with respect to a specified probability threshold of encountering severe weather, subject to collision safety, airline equity, and sector workload considerations. This approach serves as an alternative to the current practice adopted by the Federal Aviation Administration (FAA) of adjusting flight routes in accordance with the guidelines specified in the National Playbook. Our innovative contributions in this paper include (a) the concept of “Probability-Nets” and the development of discretized representations of various weather phenomena that affect aviation operations; (b) the integration of readily accessible severe weather probabilities from existing weather forecast data provided by the National Weather Service; (c) the generation of flight plans that circumvent severe weather phenomena with specified probability threshold levels, and (d) a probabilistic delay assessment methodology for evaluating planned flight routes that might encounter potentially disruptive weather along its trajectory. Additionally, we conduct an economic benefit analysis using a k-means clustering mechanism in concert with our delay assessment methodology in order to evaluate delay costs and system disruptions associated with variations in probability-net refinement-based information. Computational results and insights are presented based on flight test cases derived from the Enhanced Traffic Management System data provided by the FAA and using weather scenarios derived from the Model Output Statistics forecast data provided by the National Weather Service.     

基于一卡通平台的离校注销系统设计与实现

本文是在研究校园一卡通平台的基础上,分析现有离校流程中存在的问题,提出基于一卡通平台的离校注销系统的设计与实现方案,使得每个用户拥有符合自己情况的离校流程,用户仅需持一卡通到他所需办理的部门办理手续,取代了原有的每个用户都要跑一遍的离校转单,简化离校手续办理流程,且减少了各部门的工作量,同时为学校各个部门提供统一准确的人员离校信息及统计结果,为建立全校统一人员数据中心提供强有力的保障,有效促进数字化校园的建设.     

基于软交换的轨道交通专用通信系统的发展

阐述了轨道交通专用通信网的发展现状和问题;结合当前轨道交通规模化建设、网络化运营和智能化管理的需求,分析城市轨道交通发展软交换技术的优势;指出了基于软交换技术的IP网是未来城市轨道交通专用通信网的发展方向;在此基础上进一步论述了城市轨道交通通信专网建设软交换网络体系的网络规划,网络演进策略和旧网改造思路。     

A hybrid simulation-assignment modeling framework for crowd dynamics in large-scale pedestrian facilities

This paper presents a hybrid simulation-assignment modeling framework for studying crowd dynamics in large-scale pedestrian facilities. The proposed modeling framework judiciously manages the trade-off between ability to accurately capture congestion phenomena resulting from the pedestrians’ collective behavior and scalability to model large facilities. We present a novel modeling framework that integrates a dynamic simulation-assignment logic with a hybrid (two-layer or bi-resolution) representation of the facility. The top layer consists of a network representation of the facility, which enables modeling the pedestrians’ route planning decisions while performing their activities. The bottom layer consists of a high resolution Cellular Automata (CA) system for all open spaces, which enables modeling the pedestrians’ local maneuvers and movement decisions at a high level of detail. The model is applied to simulate the crowd dynamics in the ground floor of Al-Haram Al-Sharif Mosque in the City of Mecca, Saudi Arabia during the pilgrimage season. The analysis illustrates the model’s capability in accurately representing the observed congestion phenomena in the facility.     

规范化安全评估与港口船舶交通安全

港口船舶交通是海上交通运输系统的一个子系统。该系统所具有的危险性，可能造成的损失，人们可接受的风险值究竟如何，所有这些都依赖于有效和合理的安全评价。规范化安全评估(FSA)是近年来国外已在不断推广应用的一种安全评估方法。在简要介绍FSA特点与实施步骤的基础上，文中根据港口船舶交通安全评估的实际情况与需要，采用人工神经网络的方法对港口船舶交通系统的模型和技术路线进行了论述，并就相应人为因素的研究提出一些建议，以改进港口船舶交通安全工作和提高其安全水平。     

京张高铁八达岭地下车站BIM设计应用

八达岭长城站是我国第一座深埋地下的高铁车站,车站由80多种洞室组成,传统二维设计难以准确表达其错综复杂的空间位置。为了提高设计效率和信息交流的准确性,采用BIM设计,解决了轨道交通工程在设计、施工、运营中的难题。基于三维碰撞检查、正向智能设计,加深了对BIM设计应用方式和铁路BIM相关标准的认识。     

Learning Frontiers in the Practice of Integrated Coastal Management

Since the Rio conference in 1992 investments in integrated coastal management (ICM) have increased dramatically. National and subnational governments have undertaken many initiatives to protect and develop coastal areas. Extensive field experience has advanced understanding of the operational attributes of ICM. This article reviews the principles and operational attributes of ICM that have become well accepted, particularly from the perspective of international ICM donors and professionals. A common understanding of the fundamentals of ICM provides a base from which targeted and systematic study and assessment of ICM can be conducted. Several thematic areas are suggested where there are currently important needs and opportunities for collective study and learning in ICM. The important role of donors is emphasized in supporting collaborative learning initiatives that advance understanding of ICM, and improve and expand the practice.     

轨道交通梁式桥BIM辅助设计软件开发研究

为了满足轨道交通桥梁设计中的专业计算和建模需求,解决BIM桥梁正向设计实施困难的问题,结合轨道交通项目梁式桥的设计流程和操作习惯,提出以数据为依托的参数化解决方案。选取Bentley公司的Microstation软件进行轨道交通梁式桥设计程序开发,所开发的程序具有地质和线路专业资料获取、桥梁墩台及基础等构件管理、孔跨布置、墩台计算、一键式BIM模型创建、一键式计算和工程量清单输出等功能,为轨道交通桥梁BIM正向设计提供了有效的工具支撑。     

A piecewise-constant congestion taxing policy for repeated routing games

In this paper, we consider repeated routing games with piecewise-constant congestion taxing in which a central planner sets and announces the congestion taxes for fixed windows of time in advance. Specifically, congestion taxes are calculated using marginal congestion pricing based on the flow of the vehicles on each road prior to the beginning of the taxing window (and, hence, there is a time-varying delay in setting the congestion taxes). We motivate the piecewise-constant taxing policy by that users or drivers may dislike fast-changing prices and that they also prefer prior knowledge of the prices. We prove for this model that the multiplicative update rule and the discretized replicator dynamics converge to a socially optimal flow when using vanishing step sizes. Considering that the algorithm cannot adapt itself to a changing environment when using vanishing step sizes, we propose adopting constant step sizes in this case. Then, however, we can only prove the convergence of the dynamics to a neighborhood of the socially optimal flow (with the size of the neighbourhood being of the order of the selected step size). The results are illustrated on a nonlinear version of Pigou’s famous routing game.