Optimal seat allocation for flights with one intermediate stop

During the time prior to departure of a flight with an intermediate stop decisions must be made concerning the allocation of reserved seats to passengers requesting space on the full or partial spans of the flight. The paper presents a model for finding the maximum allowable allocation of seats on the various spans at each time prior to departure such that a maximum expected contribution to profit for the flight is obtained.The model utilizes the time distribution of reservations and cancellations for both spans. Consideration is given to the effects of waitlists, standbys and overbookings. A Bayesian reassessment of probabilities is incorporated in a sequential decision procedure. A computer program was written to perform the calculations, and the results of a short sample problem which was run to test the validity of the model are presented.     

An intelligent baggage-tracking system for airport security

The proposed baggage-tracking system is designed to improve airport security and expedite the retrieval of baggage belonging to passengers suspected of posing a threat to the safe flight of an aircraft. As passengers check in, the dimensions of each piece of their luggage are obtained via a non-invasive laser-light-sensor system, and are input to the computer. The weight of the luggage is also input to the computer. Based on a codebook associated with the flight, date, weight, dimensions, type of aircraft, the number of passengers booked for this flight and the weight and balance constraints, the computer assigns the luggage to a specific container and a specific location within the container. Furthermore, a special tag is issued by the computer. The tag denotes the container number and the position within the container of the luggage. Each tag contains an antenna responding to a very narrow band of frequencies. The antenna frequency of the tag is also input to the computer. If the passenger does not board the aircraft, this information is used to remove the passenger's luggage within a relatively short time.     

Personnel scheduling in a complex logistic system: a railway application case

In complex logistic systems, such as transportation systems, dealing with personnel scheduling is a non-trivial task. Duties have to be created and assigned to workers in a way to optimize a certain objective function. In this paper, in particular, we consider the case of scheduling train drivers on a railway subnetwork. Train driver scheduling involves the construction of feasible duties from a set of trips to be carried out by a number of train drivers. Each duty consists of a sequence of trips to be carried out by a single train driver on a single day. The duties should be such that: each trip is covered by at least one duty, each duty satisfies feasibility constraints, additional constraints involving the complete schedule are satisfied, one or several objectives are met. In this paper we focus on minimizing the number of duties and on maximizing the robustness of the obtained schedule for outside disruptions. We present an implicit column generation solution approach. We describe a heuristic procedure to find an initial feasible solution together with a heuristic branch-and-price algorithm based on a dynamic programming algorithm for the pricing-out of columns. We tested our approach on the timetable of the Intercity train series 500, 700, 1600 and 1700 of NS Reizigers, the largest Dutch operator of passengers trains.     

Airline planning benchmark problems—Part II: Passenger groups,utility and demand allocation

This paper is the second of two papers entitled “Airline Planning Benchmark Problems”, aimed at developing benchmark data that can be used to stimulate innovation in airline planning, in particular, in flight schedule design and fleet assignment. The former has, to date, been under-represented in the optimisation literature, due in part to the difficulty of obtaining data that adequately reflects passenger choice, and hence schedule revenue. Revenue models in airline planning optimisation only roughly approximate the passenger decision process. However, there is a growing body of literature giving empirical insights into airline passenger choice. Here we propose a new paradigm for passenger modelling, that enriches our representation of passenger revenue, in a form designed to be useful for optimisation. We divide the market demand into market segments, or passenger groups, according to characteristics that differentiate behaviour in terms of airline product selection. Each passenger group has an origin, destination, size (number of passengers), departure time window, and departure time utility curve, indicating willingness to pay for departure in time sub-windows. Taking as input market demand for each origin–destination pair, we describe a process by which we construct realistic passenger group data, based on the analysis of empirical airline data collected by our industry partner. We give the results of that analysis, and describe 33 benchmark instances produced.     

基于人工蜂群算法的轨道交通列车行车间隔优化

轨道交通运营组织作为轨道交通运营企业管理的核心,在降低企业运营成本、提升服务水平和旅客出行效率方面起着非常重要的作用。提出一种基于人工蜂群（ABC）优化算法的列车行车间隔优化策略,在考虑运营企业和旅客各自利益的基础上,以列车发车间隔为决策变量,建立旅客平均候车时间最小和列车等候时间最大的双目标非线性规划模型。采用ABC算法对模型进行优化求解,结合京津城际铁路某日不同时段客流基础数据进行仿真,实例验证了所提算法和模型的有效性。     

Generation of optimal schedules for metro lines using model predictive control

This paper presents a new methodology for computation of optimal train schedules in metro lines using a linear-programming-based model predictive control formulation. The train traffic model is comprised of dynamic equations describing the evolution of train headways and train passenger loads along the metro line, considering the time variation of the passenger demand and all relevant safety and operational constraints for practical use of the generated schedule. The performance index is a weighted sum of convex piecewise-linear functions for directly or indirectly modelling the waiting time of passengers at stations, onboard passenger comfort, train trip duration and number of trains in service. The proposed methodology is computationally very efficient and can generate optimal schedules for a whole day operation as well as schedules for transition between two separate time periods with known schedules. The use and performance of the proposed methodology is illustrated by an application to a metro line similar to the North-South line of São Paulo Underground.     

动车组自动报站功能测试方法

动车组自动报站功能由旅客信息系统实现,主要负责列车即将到站、到站停稳、起步离站,三个时刻进行语音和文本的自动播报,从而向旅客传递列车的运行站点信息。当完成报站功能的开发或者修改,车次线路信息的增加或者修改时,均需要对修改内容进行验证。目前动车组旅客信息系统自动报站功能的测试方法较少,传统的测试方法由测试人员添乘跟车,在列车运行过程中对每一站的语音和文字播报进行观察,从而完成本车次的报站功能验证工作。这种测试方法效率非常低,依赖现场作业环境,并且测试回归性差。为了确保自动报站功能在运行过程中的稳定性,提升测试效率,采用GPS模拟软件,根据用户测试指令模拟列车实时位置,计算列车当前位置与一下站的距离；采用MVB数据收发装置,根据用户测试指令,模拟发送列车开关门信号、列车速度信号,完成以MVB为通讯方式的旅客信息系统自动报站测试；借助动车组自动报站功能的测试方法,可以提升测试效率,为自动报站功能稳定运行提供保障。     

A conceptual solution to the aircraft gate assignment problem using 0, 1 linear programming

The U.S. commercial airline movement to “hub” operations has increased rapidly over the past several years. This trend will grow with the introduction of the Wayport concept. These giant “people exchange” facilities will feature multiple runways and massive concourses. While the Wayport developers may automate the ground movement of passengers, the sheer size of the facilities and the anticipated close scheduling of flights will confront the passenger with a problem of new dimension in getting from arrival gate to departure gate. One thing that could help alleviate the situation would be “sensible” assignment of flights to gates - sensible in that the assignment would take into account the communion of interest of the passengers. Other things being equal, the positioning of incoming flights should take into account the distribution of passengers among connecting flights. The larger the number of passengers arriving on flight X for destination A, the closer flight X should be positioned to the flight departing for A. This inquiry looks conceptually at this problem, reducing the distance passengers must walk from gate to gate. The criterion selected is minimization of the total passenger-distance travel for a given arrival-departure cycle. The problem can be conveniently cast as a 0,1 Linear Programming (LP) problem. The author discusses derivation of problem parameters and then solves several representative problems. A unique feature of the LP approach is the availability with the optimal solution of cost factors and assignments for suboptimal solutions. Minor changes in the input data do not require reworking the problem. Although the solution is characterized as conceptual, some ideas are given for practical use of the solution methodology in a dynamic airport environment.     

卧铺车厢旅客信息管理系统设计

为了改善我国铁路卧铺列车当前落后的旅客信息管理现状,设计了一种基于嵌入式的旅客信息管理系统,其包括手持信息采集终端、旅客信息管理终端和到站提醒模块。系统采用二维码识别、ZigBee无线传输、CAN总线、Linux等技术,以实现卧铺旅客信息自动采集、无线传输、汇总更新、到站提醒等功能。测试结果表明,该设计能把车厢内如铺位使用情况、旅客目的到站、列车即将到达站等信息显示在旅客信息管理终端中,有效地提高了列车员的工作效率和准确率,具有较好的工程应用和推广价值。     

基于贝叶斯网络的航班串运行脆弱性研究

为研究航班串中某一关键航班发生进离港延误对该航班串中其它航班进离港准点率造成的影响,采用贝叶斯网络对航班串运行进行建模,识别并评价关键航班的脆弱性,并提出降低航班串运行脆弱性的建议。在受到管制、天气、军事活动、航班在机场异常过站以及其它异常情况等不确定因素影响下,研究航班串进离港准点率关系,并找出航班串运行时的脆弱节点以及评价关键航班的延误状态。通过对比分析增加关键航班过站时间航班串运行前后的进离港准点率,结果表明,增加关键航班过站时间可以降低航空公司航班串运行脆弱性。     

基于编织算法的复线高速磁浮列车运行图铺画方法

根据高速磁浮线路结构和运行控制系统的特点,建立了复线高速磁浮列车运行图编制模型,设计了编织算法对模型进行求解。该算法严格按照列车在各车站的发车时间顺序,对上、下行列车运行线如同“织毛衣”般交叉铺画,在遇到列车冲突时通过更改列车路由和增加发车间隔等方法予以及时化解,逐步得到整体优化的列车运行图。算例分析表明,该方法优化速度快,能够有效地进行高速磁浮列车运行图的铺画。     

利用数字影像中直线的结构特征检测直线段

在数字影像中,理想的直线段由呈阶梯状排列的游程所构成。论文利用这一特征提出了一种检测直线段的新方法,它以逐行或逐列搜索带有缝隙的游程作为基础,搜索时能根据已取得的部分直线段预测下一段游程的起始像素位置,检测速度较快,获取的直线段较长,所得结果非常适合于用作为基元以合并成完整的直线。该算法的原理还可用来快速确定表格框线的转角。     

基于换乘导向的大型客运枢纽高铁列车接续优化

针对高速铁路成网条件下的客运枢纽高铁列车接续优化问题,分析了枢纽内的旅客换乘过程,提出了中长途客流的换乘满意度概念;以平均换乘满意度和枢纽车站列车到发均衡性为优化目标,以大站合理发车时间、合理终到时间、车站作业间隔时间、旅客换乘时间、车站到发线能力等为约束条件,建立了基于换乘协同的大型客运枢纽高速列车接续优化模型。设计了改进染色体编码方式和选择策略的遗传算法对算例进行了求解。改进后的遗传算法同基本遗传算法、基本模拟退火算法相比,目标函数中所求的平均换乘满意度分别增加了5.10%、2.93%,枢纽车站列车到发均衡性分别提高了0.27%、2.31%,算例结果验证了改进遗传算法的有效性和稳定性,表明所提方法可以有效地提高大型枢纽高铁列车的接续质量。     

Learning to detect subway arrivals for passengers on a train

The use of traditional positioning technologies, such as GPS and wireless local positioning, rely on underlying infrastructure. However, in a subway environment, such positioning systems are not available for the positioning tasks, such as the detection of the train arrivals for the passengers in the train. An alternative approach is to exploit the contextual information available in the mobile devices of subway riders to detect train arrivals. To this end, we propose to exploit multiple contextual features extracted from the mobile devices of subway riders to precisely detecting train arrivals. Following this line, we first investigate potential contextual features which may be effective to detect train arrivals according to the observations from 3D accelerometers and GSM radio. Furthermore, we propose to explore the maximum entropy (MaxEnt) model for training a train arrival detector by learning the correlation between contextual features and train arrivals. Finally, we perform extensive experiments on several real-world data sets collected from two major subway lines in the Beijing subway system. Experimental results validate both the effectiveness and efficiency of the proposed approach.     

基于深度全连接神经网络的离港航班延误预测模型

针对提升离港航班延误预测精确度困难的问题,提出一种基于深度全连接神经网络（DFCNN）的离港航班延误预测模型。首先,在考虑航班信息、机场气象与航班延误历史的基础上,考虑航班网络结构对预测模型的影响;然后,从激活函数、输入数据项及延误时间阈值三个维度进行实验,以对模型抑制梯度弥散与提升学习表现能力的能力进行了优化与验证;最后,通过调控神经网络层数的纵向拓展方式与随机丢失层的Dropout参数,提升模型的泛化能力。实验结果表明：所提模型使用tanh、指数线性函数（ELU）,预测精确度比使用线性整流函数（ReLU）分别提升了1.26、1.28个百分点;考虑航班网络结构后,所提模型采用ELU函数计算时,预测精确度比未考虑航班网络结构时提升了3.12个百分点;在时间阈值为60 min时,通过调控Dropout参数,模型的损失值不断降低;在5层隐含层网络和Dropout参数为0.3时,所提模型可以取得92.39%的预测精确度。因此,所提模型能够对国内航班延误做出较为准确的判断。     

Train scheduling and circulation planning in urban rail transit lines

This paper proposes a two-stage optimization approach to optimize the train schedule and circulation plan with consideration of passenger demand for an urban rail transit line. A train scheduling model is based on the operation of train services, which results a mixed integer nonlinear programming problem. Moreover, a train circulation model is formulated to adjust the departure and arrival times obtained by the train scheduling model to reduce the number of trains required, which results in a mixed integer linear programming problem. The case study based on the Beijing Yizhuang line illustrates the effectiveness of the proposed model and solution approach.     

Analysis of Departure Times in Discrete and Continuous Tandem Production Lines

We study the departure times in tandem production lines where the products passing through the lines are either discrete entities or continuous fluid. We call these discrete tandem (DT) or continuous tandem (CT) lines, respectively. We apply sample path analysis techniques to relate the departure time in a DT line to the departure time in a CT line where both lines have equivalent model parameters. We show that the departure time of a quantity q, produced at a machine in a DT line governed by the communication blocking mechanism, converges to the departure time of the same quantity at the same machine in the corresponding CT line as the size of the products in the DT line becomes infinitesimally small. Since continuous fluid models are used in both queueing and control systems to approximate the behavior of discrete systems, this asymptotic result enhances the understanding and the use of such models. Finally, our result also leads to an alternative proof for the convexity of the departure time in CT lines.     

旅客列车全自动报站多媒体系统

介绍了一种由下位单片机、上层PC机、通过串行通信组成的列车全自动报站多媒体系统的原理及组成和软、硬件设计。谊系统能自动识别列车所到达站点．并以多媒体形式介绍相关的交通和旅游信息，方便了旅客，改善了乘车环境，是列车报站的发展方向。     

协同决策起飞排序系统

为弥补目前国内民航空中交通运输自动化系统相对缺失的状态,实现空中交通运输参与部门协同决策航班数据,完成自动化航班起飞排序,协助管制员进行起飞调度决策,提出了协同决策起飞排序系统的总体框架.阐述了该系统的工作流程、核心模块结构设计、航班起飞约束条件和自动化起飞排序调度算法.根据用户角色职责制定用户权限,参与信息共享和航班数据协同决策.设计基于滚动时域方法的航班起飞协调调度算法,加以尾流和空中流量控制等安全约束,得到优化的待起飞航班序列,并采用时隙表方式直观的将航班序列展示给用户.最后,介绍了该系统的实际运行状况,结果表明,系统可以完成多用户协同决策、实现航班起飞管理自动化、为管制员决策提供依据.