“江苏30米级巡逻船”主机选型

国内高速巡逻艇上的主推进机组一般选用进口高速柴油机组，近年来很多进口高速柴油机进入国内市场，如何为巡逻艇选择合适的机型成为巡逻艇设计和建造的关键。本文主要介绍了“江苏30米级巡逻船”的主机选型的方法，并为高速巡逻艇的主机选型提供了借鉴。     

妈湾跨海通道工程隧道选线快速评价模型研究

为解决滨海地区跨海隧道选线难题,依托妈湾跨海通道工程,在分析影响海底隧道建设安全的地质因素的基础上,从隧道线位地质适应性角度出发,综合考虑地质条件、设计方案、施工方法等因素,基于打分制提出选线快速评价模型。模型包含平面曲率半径、纵坡坡度、抗浮安全系数、隧道埋深、与平面控制因素水平距离、差异沉降6项评价指标。选线快速评价模型前5项指标不满足设计要求时采用一票否决制,差异沉降指标考虑地下水位、土层性质、土层厚度、先期固结压力、车辆荷载等因素的影响,依据分层总和法计算隧道沉降; 同时,结合经验法推导出沉降曲率半径计算公式,并将沉降曲率半径划分为5个等级,从而构建出妈湾跨海通道工程隧道选线快速评价模型,并将其嵌入到三维参数化选线分析平台,实现隧道地质参数快速选取和隧道线位快速评价。采用选线快速评价模型对妈湾跨海通道3条盾构线位进行选线评价,评分分数分别为79.3、71.3、84.1,对隧道选线设计具有一定的参考意义。     

Airport taxi planning: Lagrangian decomposition

The airport taxi planning (TP) module is a decision tool intended to guide airport surface management operations. TP is defined by a flow network optimization model that represents flight ground movements and improves aircraft taxiing routes and schedules during periods of aircraft congestion. TP is not intended to operate as a stand‐alone tool for airport operations management: on the contrary, it must be used in conjunction with existing departing and arriving traffic tools and overseen by the taxi planner of the airport, also known as the aircraft ground controller. TP must be flexible in order to accommodate changing inputs while maintaining consistent routes and schedules already delivered from past executions. Within this dynamic environment, the execution time of TP may not exceed a few minutes. Classic methods for solving binary multi‐commodity flow networks with side constraints are not efficient enough; therefore, a Lagrangian decomposition methodology has been adapted to solve it. We demonstrate TP Lagrangian decomposition using actual data from the Madrid‐Barajas Airport. Copyright © 2011 John Wiley & Sons, Ltd.     

International experience with speed limits during and prior to the energy crisis of 1973–4

This paper presents an artificial neural network (ANN) based method for estimating route travel times between individual locations in an urban traffic network. Fast and accurate estimation of route travel times is required by the vehicle routing and scheduling process involved in many fleet vehicle operation systems such as dial‐a‐ride paratransit, school bus, and private delivery services. The methodology developed in this paper assumes that route travel times are time‐dependent and stochastic and their means and standard deviations need to be estimated. Three feed‐forward neural networks are developed to model the travel time behaviour during different time periods of the day‐the AM peak, the PM peak, and the off‐peak. These models are subsequently trained and tested using data simulated on the road network for the City of Edmonton, Alberta. A comparison of the ANN model with a traditional distance‐based model and a shortest path algorithm is then presented. The practical implication of the ANN method is subsequently demonstrated within a dial‐a‐ride paratransit vehicle routing and scheduling problem. The computational results show that the ANN‐based route travel time estimation model is appropriate, with respect to accuracy and speed, for use in real applications.     

北京南站高架桥西侧立交的选型与设计

高架桥西侧立交是北京南站近期实施方案中新建的六座节点立交之一。该文结合立交用地条件、远期的交通量预测结果,研究并确定了立交形式,为城市路网中同类立交选型提供了一些方法和经验。     

对港口起重机钢结构抗脆断设计的研究

港口起重机的钢结构是起重机的重要组成部分,是整台起重机的骨架.《起重机设计规范》(GB3811-83)对钢结构提出了抗屈服、抗失稳和抗疲劳失效的安全性核算要求,但不能保证抗脆性破坏的安全性;在F.E.M标准《欧洲起重机械设计规范》(1998年修订版)中对钢结构抗脆性破坏提出了钢材质量选择办法.本文针对现行起重机钢结构设计,从防止结构脆断的角度就如何合理选用钢材等级做一些探讨.     

用于地面带电自动过分相的智能选相真空断路器的研究

真空断路器是地面带电相分段自动转换装置的关键设备。通过对自动过分相系统暂态过程的分析，研究开发了采用永磁操作机构的智能选相真空断路器。现介绍研制采用的单稳态永磁操作机构、高压真空灭弧室、断路器同步关合技术的具体实施方案，以及智能选相真空断路器成功应用于地面带电自动过分相技术的现状。     

一种优化模型在登陆兵上船地域选择中的应用

由于在选择登陆兵上船地域过程中存在大量不确定和模糊因素，提出一种基于突变理论的优化选择模型。在简要介绍突变理论基本原理的基础上，建立上船地域优选突变评价指标体系，根据归一公式进行量化递归运算，分别计算出不同方案的总突变隶属函数值，从而确定最优上船地域，并用实例验证了该模型的合理性和可行性。     

西成铁路西安至江油段建设模式方案研究

随着我国铁路网规模及密度的扩大,合理确定铁路建设模式方案对铁路的建设成本、运营效益至关重要。针对西成铁路西安至江油段通道客货运输需求特点及项目定位,分析提出不同建设模式方案,并进行综合比选研究,提出项目采用客运专线建设模式的推荐意见。同时,探索提出关于建设模式方案研究的一点体会。