A network optimization-based approach for crowd management in large public gatherings

Effective crowd management during large public gatherings is necessary to enable pedestrians' access to and from the venue and to ensure their safety. This paper proposes a network optimization-based methodology to support such efficient crowd movement during large events. Specifically, a bi-level integer program is presented that, at the upper-level, seeks a reconfiguration of the physical layout that will minimize total travel time incurred by system users (e.g. evacuees) given utility maximizing route decisions that are taken by individuals in response to physical offerings in terms of infrastructure at the lower-level. The lower-level formulation seeks a pure-strategy Nash equilibrium that respects collective behavior in crowds. A Multi-start Tabu Search with Sequential Quadratic Programming procedure is proposed for its solution. Numerical experiments on a hypothetical network were conducted to illustrate the proposed solution methodology and the insights it provides.     

城市多模式公交网络出行时间可靠性模型研究

随着城市的发展,快速轨道交通和快速公交系统逐渐融入到常规公交系统中,构成了复杂的多模式公交网络,在此公交网络环境下乘客公交出行时间的稳定可靠程度直接影响到公交系统的服务性能,因此,本文以常规公交和地铁组成的典型多模式公交网络为研究对象,利用状态增广技术,建立了换乘约束条件下的出行时间可靠性模型,从而为评价和改善多模式公交网络服务性能提供决策支持。     

Routing and scheduling of RoRo ships with stowage constraints

Roll-on/Roll-off ships are used for international transport of vehicles and other rolling equipment. We consider the problem where a ship sails between two geographical regions, picking up cargo in the first and making deliveries to the second. Several variations are considered with optional cargoes, flexible cargo quantities, and ship stability restrictions. Decisions must be made regarding the route and schedule of the ship as well as the stowage of cargo onboard. The problem is modeled as a mixed integer program, which has been solved using Xpress. In addition, a tailor made heuristic procedure is built using components from tabu search and squeaky wheel optimization. Extensive computational results are presented, showing that the heuristic is able to handle realistically sized problem instances.     

一种多功能智能搜救小车的设计

由于灾害现场搜救人员难以迅速展开救援工作,设计出本小车,小车以STC89C52单片机为核心控制器,采用WIFI模块进行人机互交,体感、声感和光感模块辨别位置,机械手执行用户操作,红外和超声波组合进行避障。小车拥有成本低廉,操作方便,救援迅速等优点,具有较好的推广意义。     

对山区河流船舶搜救的思考

山区河流的航行条件相对恶劣,如发生船舶失事事故,难以开展有效的搜救及协调工作。文章针对山区河流特点和船舶失事特点,分析了山区河流流域船舶航行的安全隐患,并从多方面探讨了加强山区河流船舶搜救工作的措施。     

基于知识管理的网络办公系统的设计和开发

首先介绍了OA的演变过程和知识管理的基本概念,然后根据实际的开发经验提出了知识管理如何应用在OA中的一种框架和实现方法.     

基于引力搜索算法的多层甲板舱室分布设计方法

舰船舱室布置设计过程复杂繁琐,需耗费大量的人力与时间,而目前计算机辅助船舶设计技术仍以三维建模与绘图为主。为了使计算机获得根据输入的设计要求自主输出舱室分布设计方案的能力,提高舰船舱室布置设计效率,提出一种舱室分布设计方法。首先,针对舱室在舰船多层甲板上的分布问题搭建数学模型,依据设计规范、统计规律以及设计经验等,在分析舱室布置要求的基础上建立环境因素、通达性、重量分布和面积目标函数。然后,将引力搜索算法引入到模型中,从而形成一套舱室分布设计方法。通过算例进行试验,结果显示由所提出的方法得出的设计方案可较好地符合设计要求,证明该方法具有一定的合理性。     

土坡三维最危险滑动面搜索方法

文章基于均质土坡旋转椭球形滑动面的假设,提出了一种用遗传算法确定均质土坡三维最危险滑动面及其对应的最小稳定系数的方法。该方法模拟了生物遗传进化的过程,克服了传统方法容易陷入局部极小值的缺点,是一种全局优化算法。     

A method for solving the multi‐objective transit frequency optimization problem

Frequency setting takes place at the strategic and tactical planning stages of public transportation systems. The problem consists in determining the time interval between subsequent vehicles for a given set of lines, taking into account interests of users and operators. The result of this stage is considered as input at the operational level. In general, the problem faced by planners is how to distribute a given fleet of buses among a set of given lines. The corresponding decisions determine the frequency of each line, which impacts directly on the waiting time of the users and operator costs. In this work, we consider frequency setting as the problem of minimizing simultaneously users' total travel time and fleet size, which represents the interest of operators. There is a trade‐off between these two measures; therefore, we face a multi‐objective problem. We extend an existing single‐objective formulation to account explicitly for this trade‐off, and propose a Tabu Search solving method to handle efficiently this multi‐objective variant of the problem. The proposed methodology is then applied to a real medium‐sized problem instance, using data of Puerto Montt, Chile. We consider two data sets corresponding to morning‐peak and off‐peak periods. The results obtained show that the proposed methodology is able to improve the current solution in terms of total travel time and fleet size. In addition, the proposed method is able to efficiently suggest (in computational terms) different trade‐off solutions regarding the conflicting objectives of users and operators. Copyright © 2017 John Wiley & Sons, Ltd.