5G技术在航运业中的应用趋势及对策建议

第5代移动通信(5th Generation Mobile Networks,5G)技术具有超大带宽、超低时延和超多连接等特性,将其与人工智能、物联网、大数据和高精度定位等关键技术高效融合,能加速推动航运业的信息化、智慧化发展。对此,分析5G的关键技术特征和产业链价值,论述5G等关键技术在智慧航运、智慧物流、智慧港口、智能制造和智慧金融等5大领域的创新趋势应用。在此基础上,提出全球航运企业运用5G促进自身发展的对策建议。     

The design and commissioning of a fully elastic model of a uniform container ship

Experimental hydroelasticity has not followed the rapid evolution of its computational counterpart. Hydroelastic codes have changed significantly in the past few decades, moving to more detailed modelling of both the structure and the fluid domain. Physical models of ships are, even today, manufactured with a very simplified structural arrangement, usually consisting of a hollow rectangular cross section. Appropriate depiction of the internal structural details ensures that properties relevant to antisymmetric vibration are scaled accurately from the real ship to the model. Attempts to create continuous, ship-like structures had limited success, as manufacturing constraints did not allow for much internal structural detail to be included. In this investigation, the first continuous model of a ship with a detailed internal arrangement resembling a container ship is designed, produced using 3D printing and tested in waves. It is demonstrated that the global responses of the hull in regular head waves agree well with theory and past literature, confirming that such a model can represent the behaviour of a ship. Furthermore, it is found that the model is capable of capturing local responses of the structure, something that would be impossible with “traditional” hydroelastic ship models. Finally, the capability of the model to be used to investigate antisymmetric vibrations is confirmed. The methodology developed here opens a whole new world of possibilities for experiments with models that are tailored to the focus of the investigation at hand. Moreover, it offers a powerful tool for the validation of modern state-of-the-art hydroelastic codes. Ultimately, it creates the next step in the investigation of dynamic responses of ship structures, which contribute significantly to accumulating damage of the hull. Better understanding of these responses will allow designers to avoid over-engineering and use of big safety factors to account for uncertainties in their predictions.     

中韩造船业国际竞争力对标分析

为迎接全球船舶行业面临的世界经济发展停滞和船海市场需求不足带来的严峻挑战,全面对标分析中国造船企业与世界一流的韩国造船企业之间的差距。对比2020年中韩造船三大指标和主要船型建造的实动工时与关键周期数据,对中韩造船企业在设计、生产、管理等三大方面的精细化、标准化、机制模式等关键性问题进行对标分析,找出原因并提出解决问题的建议。中国造船业应积极开展常态化、精细化的对标工作,准确研判新发展格局带来的新机遇、新挑战,明确主攻方向,聚焦关键环节,找准融入新发展格局的着力点和突破口。     

船舶云制造服务平台及运营模式研究

船舶制造由传统的制造模式向服务化制造的转变是未来船舶制造业的发展趋势。根据船舶制造特点及云制造理念,提出了船舶云制造服务的概念模型和信息模型,设计了船舶云制造的系统结构和云制造服务平台的架构及运营模式,以实现一定区域范围内,船舶制造资源与制造任务间最大限度的快速匹配,实现船舶制造过程和管理的服务化、集约化。     

甬江大桥钢箱梁拉索锚箱的制造工艺分析

介绍宁波甬江大桥钢锚箱构造的特点,重点分析锚箱的装配及焊接工艺,以及锚箱制作工艺的优化、控制焊接变形等各种工艺措施。     

Can regional transportation and land-use planning achieve deep reductions in GHG emissions from vehicles?

The Intergovernmental Panel on Climate Change estimates that greenhouse gas emissions (GHG) must be cut 40–70% by 2050 to prevent a greater than 2 °Celsius increase in the global mean temperature; a threshold that may avoid the most severe climate change impacts. Transportation accounts for about one third of GHG emissions in the United States; reducing these emissions should therefore be an important part of any strategy aimed at meeting the IPCC targets. Prior studies find that improvements in vehicle energy efficiency or decarbonization of the transportation fuel supply would be required for the transportation sector to achieve the IPCC targets. Strategies that could be implemented by regional transportation planning organizations are generally found to have only a modest GHG reduction potential. In this study we challenge these findings. We evaluate what it would take to achieve deep GHG emission reductions from transportation without advances in vehicle energy efficiency and fuel decarbonization beyond what is currently expected under existing regulations and market expectations. We find, based on modeling conducted in the Albuquerque, New Mexico metropolitan area that it is possible to achieve deep reductions that may be able to achieve the IPCC targets. Achieving deep reductions requires changes in transportation policy and land-use planning that go far beyond what is currently planned in Albuquerque and likely anywhere else in the United States.     

Impact evaluation of a mass transit fare change on demand and revenue utilizing smart card data

Transit fares are an effective tool for demand management. Transit agencies can raise revenue or relieve overcrowding via fare increases, but they are always confronted with the possibility of heavy ridership losses. Therefore, the outcome of fare changes should be evaluated before implementation. In this work, a methodology was formulated based on elasticity and exhaustive transit card data, and a network approach was proposed to assess the influence of distance-based fare increases on ridership and revenue. The approach was applied to a fare change plan for Beijing Metro. The price elasticities of demand for Beijing Metro at various fare levels and trip distances were tabulated from a stated preference survey. Trip data recorded by an automatic fare collection system was used alongside the topology of the Beijing Metro system to calculate the shortest path lengths between all station pairs, the origin–destination matrix, and trip lengths. Finally, three fare increase alternatives (high, medium, and low) were evaluated in terms of their impact on ridership and revenue. The results demonstrated that smart card data have great potential with regard to fare change evaluation. According to smart card data for a large transit network, the statistical frequency of trip lengths is more highly concentrated than that of the shortest path length. Moreover, the majority of the total trips have a length of around 15 km, and these are the most sensitive to fare increases. Specific attention should be paid to this characteristic when developing fare change plans to manage demand or raise revenue.     

Route choice stickiness of public transport passengers: Measuring habitual bus ridership behaviour using smart card data

This paper explores how we can use smart card data for bus passengers to reveal individual and aggregate travel behaviour. More specifically, we measure the extent to which both individual and bus routes exhibit habitual behaviour. To achieve this, we introduce a metric called Stickiness Index to quantify the range of preferences of users that always select to travel on the same route (high stickiness) to those with a more varied patterns of route selection (low stickiness). Adopting a visual analytic and modelling approach using a suite of regression models we find evidence to suggest that stickiness varies across the metropolitan area and over a 24-h period wherein higher stickiness is associated with high frequency users where there is substantial variability of route travel times across all alternatives. We argue that our findings are important in their capacity to contribute to a new evidence base with the potential to inform the (re)-design and scheduling of a public transit systems through unveiling the complexities of transit behaviour.     

产品设计由标准化迈向定制化

人类工业化历史经历了从手工作业到流水线生产再到柔性制造3个发展阶段,其中,大规模流水线生产是标准化运用的巅峰,因为流水线生产对标准化的要求最高,其对产品的设计标准化、工艺标准化和生产标准化等都提出了严格要求.然而,伴随着中国工业化程度的进一步加深,市场竞争愈发激烈,同质化产品越来越多,为了进一步提高自身产品的竞争力,越...     

轨道交通装备制造业发展趋势分析

在对"十一五"期间轨道交通装备制造业调研基础上,研究并构建由约束性和评价性两大类发展指标构成的轨道交通装备制造业发展指标体系,结合2006-2009年我国轨道交通装备制造业主要发展指标的实证研究与统计分析,对装备制造业发展趋势进行预测,为合理制定"十二五"期间轨道交通装备发展规划提供量化的科学依据.研究结果表明,随着轨道交通大规模建设的展开和相继投入运营,轨道交通装备制造业的主要经济效益快速增长,节能降耗取得明显成效,科技创新能力大幅度提高;"十二五"期间轨道交通装备将继续呈现大幅增长,动车组、大功率机车、货车的新造需求量与保有量相比将分别有60%,40%,30%以上的增长,城轨车辆的新造需求量与保有最相比将有90%以上的增长.