基于驾驶员偏好的最优路径选择

现实生活中,驾驶员往往依据自身偏好来选择路径,对不同的路径属性有不同的要求,且对其属性值存在一个可接受范围,而不是一个精确值. 本文对存在驾驶员偏好的最优路径选择问题进行了研究,提出了一种能够综合反映驾驶员偏好的最优路径选择方法. 首先基于可能度和区间数相离度的多属性决策方法,建立驾驶员偏好与路径属性总偏差最小的优化模型,并解出路径属性权重;其次算出各路径的综合属性值,建立路径间的可能度矩阵及其排序向量,据此选出最优路径;最后以算例进行验证,结果表明本文给出的路径选择方法具有很好的可行性和适用性.     

Collision-avoidance under COLREGS for unmanned surface vehicles via deep reinforcement learning

ABSTRACT

Collision avoidance for unmanned surface vehicles (USVs) is significant for the fulfillment of autonomous navigation. Generally, classical collision-avoidance algorithms are proposed for relatively simple encounter situation, in this scenario only two USVs are stressed. Furthermore, to generate the rational manoeuvre operations, it is necessary that USVs should abide by International Regulations for Preventing Collision at Sea (COLREGS). However, COLREGS has not paid attention to rules for multi-USV collision-avoidance problem. Furthermore, those collision-avoidance rules in COLREGS have not been quantified for USVs. Following that, this paper utilizes deep reinforcement learning (DRL) algorithm to resolve collision-avoidance for USVs even in complex encounter situations. Within our DRL algorithm, related COLREGS is quantified properly and integrated into the DRL model, and then encounter situation of USVs is formulated as environmental observation value, accordingly a set of decision making is reached by decision-making neural network, and the reward function is designed for updating network parameters iteratively. Consequently, collision avoidance for USVs can be achieved eventually. By employing our DRL algorithm, collision avoidance for USVs under generous complex scenarios are resolved with the aid of corresponding intelligent decision-making operations. Simulation results verify the effectiveness of our DRL algorithm.     

基于市民生活行为学的交通行为研究综述

对交通行为的研究应该打破传统研究方法，转向基于市民生活行为学(狭义：生活导向型方法论)的研究方法。市民生活行为学侧重于考量生活选择之间的相互依存关系，不仅主张交通行为是各种生活选择的结果，也主张生活选择受交通行为的影响。这些主张既有理论基础也有实证依据，因此，涉及市民生活的各种决策需要不同部门的沟通与合作，这种沟通与合作需要有共同语言。市民生活行为学既为跨部门交通规划与管理提供全新的理论，也是服务于跨部门城市与区域政策(公共政策)的全新理论。市民生活行为学作为跨学科的理论体系，有望成为支持跨部门决策的通用语言。本文首先介绍市民生活行为学及其在交通行为研究的应用。其次，针对生活方式、汽车依赖、家庭能源消耗、信息通信技术与生活、健康与生活选择、旅游行为、老年人出行、年轻人风险行为、自然灾害应对及生涯流动在内的10个与交通行为密不可分的热点话题，介绍了基于市民生活行为学的交通行为研究进展。最后，提出基于市民生活行为学的交通行为研究的挑战与展望。     

分段式尾压浪板对高速船阻力性能的影响

基于CFD技术,以排水型高速船Model 5b为模型,寻求改善高速船阻力性能的尾压浪板新形式。首先尾压浪板新形式的确定在静水条件下进行,然后在波浪条件下验证该压浪板的阻力性能。基于CFD软件建立三维数值波浪水池,静水条件下采用切割体网格技术预报船模的阻力性能。波浪条件下数值水池入口采用直接造波方法,尾部采用人工阻尼消波方法,自由面采用VOF方法处理,采用重叠网格技术预报船模的阻力性能以及运动响应。确定一种比常规压浪板阻力性能优良的分段式压浪板,为船舶节能附体的研究提供参考。     

A new rule-based integrated decision making approach to container transshipment terminal selection

The choice of the port or terminal to perform transshipment operations is a critical decision for container transportation companies (i.e. shipping line companies). This choice is not only affected by transshipment costs but also by the location, infrastructure, equipment, and technologies of the alternative terminals. In this study, a rule-based integrated multi-criteria group decision making approach is proposed in order to support such complex decision processes which involve substantial uncertainties and subjectivities. The proposed approach involves simple mathematics and provides a flexible modeling approach close to human reasoning that is able to consider uncertain information and relationships of arbitrary complexity. To prioritize the sub-criteria affecting the choice of the most appropriate terminal and to assess alternatives with respect to these sub-criteria, the Analytic Hierarchy Process (AHP) based on absolute measurement is used. Then, to determine the most appropriate terminal, a Fuzzy Rule-Based System is developed, which adopts the scores of criteria (i.e. the total scores of sub-criteria) obtained by AHP as input. In order to demonstrate the applicability and effectiveness of the proposed approach, an application is presented for the choice of the most appropriate container transshipment port in Turkey for a shipping line company.     

Calculation of the freight revenues in Turkey-focused maritime transportation

The Central Bank of the Turkish Republic (TCMB) in Turkey has announced the data of freight revenues. The data that have been announced depends on the information obtained from the port customs and compiled by the Turkish Statistical Institute (TUIK). Because of the distinctive structure of the freight market, certain requisite generalizations and projections are used for data calculation. Accordingly, calculations that depend on generalizations and predictions are likely to weaken the effectiveness of the decisions already made or going to be made. The aim of this study is to calculate more realistically the real freight revenues of ships that have carried out loading or discharging operations in Turkish ports. In accordance with this purpose, the volume of freight revenues and their distribution between Turkish and foreign flagged ships is calculated. A Microsoft SQL-based algorithm is developed in order to do the calculation. Within the scope of the study, the total fright revenue of Turkey-oriented shipping industry is calculated to be USD 5.8 billion. Proportionately, 79.53% of the revenue belongs to foreign flagged ships, 12.70% of it belongs to foreign flagged ships with Turkish owners, and only 7.78% of it belongs to Turkish flagged ships.     

A behavioural comparison of route choice on metro networks: Time,transfers, crowding,topology and socio-demographics

Understanding travellers’ behaviour is key element in transportation planning. This article presents a route choice model for metro networks that considers different time components as well as variables related to the transferring experience, train crowding, network topology and socio-demographic characteristics. The route choice model is applied to the London Underground and Santiago Metro networks, to make a comparison of the decision making process of the users on both cities. As all the variables are statistically significant, it is possible to affirm that public transport users take into account a wide variety of elements when choosing routes. While in London the travellers prefer to spend time walking, in Santiago is preferable to spend time waiting. Santiago Metro users are more willing to travel in crowded trains than London Underground users. Both user groups have a similar dispreference to transfers after controlling for the time spent on transfer, but different attitudes to ascending and descending transfers. Topological factors presented on a distorted Metro map are more important than actual topology to passengers’ route choice decisions.     

有效的阅读是学好英语的关键

本文从目前大学生学习英语的困惑入手,论述了兴趣是学好英语的根本;分析了大量阅读对英语学习至关重要的原因;并提出了有效阅读是培养大学生学习英语的自信心以及获得成功的关键。     

智能管理系统的概念结构

智能管理系统是一个由核心、若干业务处理主体、若干智能支持机制组成的具有自动决策、自动处理、自适应能力的面向解决管理问题的系统。本文研究了智能管理系统的概念、结构、工作原理、能力、智能支持机制。     

绿色交通原则指导下的城市轨道网规划综合评价

为在轨道交通线网规划方案中选取最佳方案，根据绿色交通原则，建立了综合评价指标体系．利用层次分析法提出了合成权重的优化算法，进而用信息熵技术和已知方案的信息修正合成权重，用基于理想解的排序方法评选出最优方案．以某城市轨道交通规划为例说明了综合评价决策方法的应用过程，所得结果与专家评审意见一致．