A combined tramp ship routing,fleet deployment,and network design problem

In this paper, a tramp ship routing model of fleet deployment in a hub-and-spoke network is presented. This model simultaneously determines the selection of hubs, the assignment of spokes to hubs, the deployment of feeder-containerships as well as containership routing between spokes and spokes, hubs and spokes, and hubs and hubs. Even though some parts have been studied, this complex combination of shipping problems has never been addressed. Because the problem is NP-hard, a genetic algorithm (GA) with local search is proposed. In the algorithm, a cut-off procedure is applied to fleet deployment in a sub-route strategy. A number of randomly generated problem instances are solved by both a mathematical program and the GA with local search. A simple but realistic heuristic algorithm is also developed. Both the GA with local search and the heuristic algorithm are used to solve a number of real case instances. A comparison of the results shows the efficiency of the GA with local search. The developed model can be used as a route-decision support tool for shipping companies that provide long-haul shipping services in a hub-and-spoke network.     

Cruise port centrality and spatial patterns of cruise shipping in the Asian market

This paper investigates the centrality of cruise ports in the Asian cruise shipping market while proposing the hubs and authorities centrality (HACC) metric as a directional synthesis of the hubs centrality and authorities centrality to explore cyclical and directional features of centrality in the cruise shipping network. With the development of the cruise shipping industry, research has been actively conducted with a particular focus on identifying the characteristics of hub ports. This paper employs social network analysis to investigate the HACC which is originally developed for analyzing the cruise port centrality problem. Empirical study implies that Ho Chi Minh City, Hong Kong, Nagasaki, Penang, Phuket, Port Klang, Shanghai, and Singapore (in alphabetical order) reflects particulars of cruise hub ports. One of the exceptional results of this paper is Ho Chi Minh City, Penang, Phuket, and Port Klang have demonstrated high HACC (refers to hub ports) while limited degree and betweenness centrality. In contrast, Busan and Keelung are not classified as hub ports.     

Spatial pattern of the global shipping network and its hub-and-spoke system

Port system is a research focus of transport geography, and most studies believe carriers are important factors in the development and concentration of the port system. Since the 1990s, carriers have played an important role in organizing the global shipping network and reorganizing the port system. But there isn’t a perfect method to evaluate carriers’ influence and the roles of each port in the maritime shipping networks. In this paper, we use the monthly schedule table of international carriers to describe and model the spatial pattern of the global shipping network and identify its hub-and-spoke system. The result shows that a hierarchical structure exists in the global shipping network. The North Hemisphere, especially the East Asia and the Southeast Asia, is a dominant region of the worldwide shipping network. East Asia, Southeast Asia, Northeast Europe, and East coast of the USA are the concentration regions of worldwide shipping lines. The ports of Hong Kong, Singapore, Shenzhen, Shanghai, and Kaohsiung etc have advanced capacity for maritime shipping and high potentials for being hub ports in the global shipping network. Today, the worldwide shipping network is transforming from the multi-port calling system to 44 regional hub-and-spoke systems. Meanwhile, the sub-networks with hub ports of Antwerp, Singapore, and Hong Kong have become the most important ones and dominate the whole global shipping network.     

Will China’s airline industry survive the entry of high-speed rail?

This study investigates the effects of high-speed rail (HSR) services on Chinese airlines. Our analysis suggests that the HSR service will be competitive in terms of network connectivity, total travel time and cost efficiency. On the other hand, growth of the Chinese airline industry has been unbalanced in terms of traffic distribution, airline network development, airport capacity and share of international traffic. While the long term prospects of Chinese airlines are bright, the carriers must develop effective hub-and-spoke networks and increase their competitiveness in international markets in order to achieve sustainable growth in the coming years. For the Chinese government, continued investment at hub airports and support to low-cost carriers are also necessary.     

A reactive container rerouting model for container flow recovery in a hub-and-spoke liner shipping network

This paper focuses on the container rerouting due to a disruption, aims at making the optimal container flow recovery plan for the affected liner shipping company. First, we make the initial effort to bring up with a basic framework of disruption management for liner shipping. Second, we present a compact integer linear programming model for addressing the container rerouting problem under the proposed framework in a hub-and-spoke liner shipping network, based on a given recovery vessel schedule that determines to omit a port of call. Other shipping companies’ services and other modes (roadway, railway, and airline) as candidate alternative means to transport the miss-connected containers are also incorporated in the proposed model. The container flow recovery plan would select the optimal alternative paths for the miss-connected containers balancing the trade-off between container transport costs and delivery delay penalty costs. Finally, a case study from a global liner shipping company is investigated and the computational results indicate the model can be solved effectively and efficiently for the real-scale problem. Thus, the proposed approach in this paper can supply real-time decision support tool for the liner shipping operators on handling the process of container flow recovery.     

Dynamic programming of port position and scale in the hierarchized container ports network

A hierarchized container ports network, with several super hubs and many multilevel hub ports, will be established, mainly serving transshipment and carrying out most of its business in the hub-spoke mode. This paper sums up a programming model, in which the elementary statistic units, cost and expense of every phase of any shipment are the straight objects, and the minimum cost of the whole network is taken as the objective. This is established based on a dynamic system to make out the hierarchical structure of the container ports network, i.e. the trunk hub and feeder hubs can be planned in a economic zone, then the optimal scale vector can also be obtained for all container ports concerned with the network. The vector is a standard measurement to decide a port's position and their scale distribution in the whole network.     

Dynamic programming of port position and scale in the hierarchized container ports network

A hierarchized container ports network, with several super hubs and many multilevel hub ports, will be established, mainly serving transshipment and carrying out most of its business in the hub-spoke mode. This paper sums up a programming model, in which the elementary statistic units, cost and expense of every phase of any shipment are the straight objects, and the minimum cost of the whole network is taken as the objective. This is established based on a dynamic system to make out the hierarchical structure of the container ports network, i.e. the trunk hub and feeder hubs can be planned in a economic zone, then the optimal scale vector can also be obtained for all container ports concerned with the network. The vector is a standard measurement to decide a port's position and their scale distribution in the whole network.     

Dynamics of change in the port system of the western Mediterranean

The ports of Mediterranean basin have experienced significant growth in container traffic over the last decade. In the western Mediterranean two distinct types of port have emerged: the established ports of the northern part of the basin which serve a gateway function and a set of new ports in the south which act as transhipment hubs. In this paper we explore the dynamics of change and reveal how growth is driven by shifts in individual trades. While the hub ports are integrated into Asian pendulum services, the gateway ports are experiencing growth because of new direct services to Asia and North America. We suggest that the distinctions between the transhipment hubs and the gateway ports are becoming blurred, especially because the gateway ports are also assuming greater transhipment roles. We also explore whether this new dynamism in the Mediterranean ports is reversing the long-standing hinterland domination of the ports of the northern range. We demonstrate that the gateway ports of the western Mediterranean continue to serve local and regional markets, with very limited penetration north of the Alps and Pyrenees. This is due in part to difficulties with rail services but also because of the continued efficiency of the northern range ports and their hinterland connections. We suggest that in the short run, at least, little change is likely.     

A model to identify airport hubs and their importance to tourism in Brazil

Air transportation in Brazil has been recently liberalized and one of the consequences of this process is the concentration of flights in a few hubs. During the years 2006-2007 two fatal accidents created unprecedented chaos in both land and air sides of the system with harmful consequences to tourism in Brazil. The consequences were more airport congestion and many episodes of flight delays and cancellations that lasted for several months. We argue that, among other factors, this state of blackout was a result of the increase in the degree of concentration in few airports, particularly Congonhas (in São Paulo) and Brasília. Using data obtained from a survey with Brazilian experts, a comparison was made with two existing methods (the one used by the US Federal Aviation Administration and the usual Herfindahl-Hirschman method) in order to calculate the number of hubs in Brazil. Due to the huge discrepancy obtained between data from the survey and the other two methods considered, a new mathematical method based on the Herfindahl-Hirschman Index was proposed to identify the number of hubs in a given network. Drawing from the examples of what happened to tourist destinations during and after the air transport crisis in Brazil, the article concludes discussing the need for a more accurate tool to identify and to monitor the concentration of flights at the Brazilian air transportation network and its importance to tourism.     

Spatial heterogeneity of ports in the global maritime network detected by weighted ego network analysis

More extensive attention has been paid to the heterogeneity of maritime transport network in topological rather than in spatial aspects. However, the importance of links and the roles of neighbors of a node has been ignored if not all. To fill this gap, this article introduced the approach of weighted ego network analysis (WENA) to visualize the spatial heterogeneity of the maritime network at global and local levels. The topological connectivity graph of the global marine network was derived, and its structural properties were analyzed. It is found out that the values of the degree of ports follow power-law distribution, which indicates that the global marine network is scale-free, that is, there are few well-connected ports and a majority of less connected ports. The spatial disparities of the network can be described by a core–periphery pattern. In global, most of the hubs or ports with extremely high values of degree locate in the big-three maritime regions including Far East, North America, and West Europe. Along the peripheral belts of the three regions, there are lots of less connected small ports. A different hierarchical structure of six continents was captured by WENA. It is found that Europe, Asia, North America, and Africa showcase a pyramid-shaped hierarchical structure with a scale-free feature similar to the entire network, while South America and Oceania exhibit the fusiform hierarchy like small-world networks. It is proposed that such spatial inequality and heterogeneity were caused by the geographical environments such as the hub-and-spoke organization, the embedded trade pattern, and the proximity of location. These findings help us to understand the characteristics of the international trade pattern and shed light on the strategies of development for the industry stakeholders.     

Port resources rationalization for better container barge services in Hong Kong

The manufacturing base in the Pearl River Delta of China is moving westwards, where the Pearl River system has extensive coverage. This makes container barge transport a new growth area for Hong Kong Port. Traditionally, Hong Kong Port has been the main gateway for containers transported through the Pearl River system, but this advantageous position is under challenge from the adjacent ports in South China, especially from Shenzhen Port, which is keen to take a bigger share of the new growth by improving the access of barges to its port facilities. While services at Shenzhen Port are improving, barge operators have been experiencing high congestion at Hong Kong Port. Improving the quality of barge container services becomes crucial for Hong Kong Port. In this study, we propose and investigate three improvement strategies: to enhance the consolidation of small container flows, to increase the efficiency of berth allocations for barges, and to optimize the overall utilization of port resources in Hong Kong. These strategies can be instrumental for keeping Hong Kong's status as the gateway for the Pearl River system and help maintain its competitiveness as an international shipping hub.     

基于改进蚁群算法的物流网络

文中将受容量限制的单分配轴-辐式网络抽象为一个三次变量的混合整数线性规划模型方程;提出了一种改进的蚁群算法,将6种局域搜索算子加入算法中,因此具有较高的全局搜索能力和局部搜索能力;同时提出“解对”的概念,对问题的构成进行分解优化,转化为确定问题,切实使本问题符合蚁群算法使用的前提和优势;最后,使用澳大利亚邮政的数据进行选址仿真实验,验证此算法模型在该应用中的求解效率和计算稳定性。     

基于航电一体化的梯级枢纽运行模式优化*

提出一种基于航电一体化的梯级枢纽运行模式优化研究方法。对整个航道进行断面划分,并在各枢纽处设置虚化断面,对航道天然断面和枢纽所在的虚化断面分别采用求解圣维南方程和考虑枢纽调度的水量平衡计算方法,确定断面水位和流量过程,实现全航道断面水力要素的同步计算,满足梯级通航枢纽联合调度对航道水位和口门区流速的高计算精度要求;并在此基础上构建梯级通航枢纽联合优化调度模型,渠化航道,改善口门区和引航道水流条件,同时优化发电策略,实现梯级通航和发电综合利用效益最大化。衢江梯级通航枢纽结果表明,构建模型具有较高的模拟精度,有效提高了梯级通航保证率和总发电量。     

Development of port service network in OBOR via capacity sharing: an idea from Zhejiang province in China

The ‘Silk Road Economic Belt and the 21st-Century Maritime Silk Road’ (One Belt One Road, OBOR) strategy initiated by the Chinese government has a significant impact on the business and logistics modes which involves Asia, Europe, Africa, and their adjacent seas. Many countries and ports are developing new strategies that are suitable for this economic environment. Compared with many ports in the world, the ports in Zhejiang province of China have a novel property. In addition to Ningbo-Zhoushan port, there are several other sea ports and river ports in that province. In this paper, we propose a concept of port service network that consists of a huge hub and multiple ports. Ports of small and medium sizes can share their capacities of different types of port service with the hub when the service capacities are integrated into the network. We develop a mixed integer nonlinear programming model to determine the optimal decisions in such a network with constraints on the budget to conduct integration. An optimization algorithm incorporated with a genetic algorithm is developed to solve large size problems. We provide managerial insights on the policies of government, including expanding port capacity, reducing fixed integration cost, and providing better financial condition.     

Port system evolution – the emergence of second-tier hubs

Some evidence has emerged of second-tier hubs inserting themselves between hubs and feeder ports, producing a new hierarchy of port networks. This article aims to establish the dynamics of this process based on illustrative cases in Asia, South America, and Europe. Findings reveal spatial factors to include a cluster of small ports with minimal sailing distance within a given range, suitable channel and berth depth, and ideally high capacity inland links. From the economic perspective, demand-side factors include a local captive market and aggregated demand to be captured from other ports, while supply-side factors include diseconomies of scale at traditional hubs, an increase in direct services, an increase in large feeder vessels calling from first-tier hubs which are then transhipped to smaller feeders for serving local ports, and an increase in overland servicing of local smaller ports. From a strategic perspective, vertical and horizontal integration in the shipping sector has produced extensive network economies, whereby shipping lines look to create group-specific port hierarchies, enhanced in the presence of aggressive management strategies and supportive policies. This finding suggests that proactive port stakeholders can in certain circumstances seize the opportunity to capture this role within their port range.     

基于混沌优化的港口集装箱运输网络优化

随着集装箱船舶大型化的发展,航运公司势必会尽可能的选择科学、合理的航线,以实现大型集装箱船的规模效益,降低单箱运输成本,从而获得更大的效益。这样集装箱港口出现了枢纽港与支线港的分离。本文以体现大型集装箱船的规模效益为前提,尝试将混沌优化这一理论应用到港口运输网络的优化中,寻找合理的港口集装箱运输线路及服务频率,为我国港口集装箱运输提供决策依据。     

The role of dry port in hub-and-spoke network under Belt and Road Initiative

Dry port plays increasingly an important role in the integration of inland regions with seaports, and cross-border inland ports especially in the context of Belt and Road Initiative (BRI) originally proposed by China. This paper studies a logistics network connecting the inland regions by dry ports based on a two-stage logistical gravity model. First, a basic logistical gravity model is developed to analyze the radiated inland regions from dry ports, where the logistical quality of dry ports is calculated by principal component analysis. Second, considering mutual impacts among dry ports, seaports and cross-border inland ports, the influence of logistical gravity on the network is examined by using a coefficient based on the Ordered Weighted Averaging Operator in multi-attribute decision theory. An improved logistical gravity model is further developed to investigate the logistical connections among various ports (e.g. dry ports, seaports and cross-border inland ports; hub and feeder ports). Then, a hub-and-spoke network can be established. Dry ports are potential to connect to the Silk Road Economic Belt and the 21st-Century Maritime Silk Road. So a Chinese case is used to verify the proposed method. The strategies of embedding inland regions in the BRI are discussed based on the experimental studies.     

调距桨桨毂机构与轴系系统的抗冲击有限元分析

针对某型调距桨桨毂机构建立有限元模型,考虑将瞬时冲击作用等效为静力载荷,以惯性力的形式施加于桨毂机构上,并基于模态叠加的思想,求解等效静力载荷,进而获得该阶次模态下桨毂机构各构件的应力响应结果,最终计算调距桨机构中螺栓连接件的等效冲击应力。     

Financial and environmental impacts of hypothetical Finnish dry port structure

One main theme of European Union’s in transport policy statements has been the increased role of railways in the reducing environmental impacts and costs of transport activity. One option to increase the modal share of rail transport is to utilize the dry port concept, particularly applicable to general cargo. At the Port of Gothenburg (Sweden) use of this concept in combination with rail transport has led to a reduction of CO₂ emissions, and lower transport energy costs. The main objective and motivation of this research work are to examine through analytical models, how this same dry port concept could be implemented in the Finnish transportation network, with estimates of the benefits being gained.The research method of this study is macro gravitational models of distribution. Main input data for the models are distances and population in the area. The approach aims to research, how relative transport costs behave by increasing the number of dry port distribution locations. For the actual computation work the authors apply linear integer programming. Based on the results, the authors argue that relative transport costs can decrease considerably by increasing the number of dry ports, up to the level of six locations. This is considerably less than what is the current situation in Sweden. The found solution also differs from Sweden as the fragmented Finnish seaport system enables using numerous seaports instead of one, which further decreases inland transportation distances and volumes considerably. At the same time forthcoming sulphur emission reduction regulation (for sea transports) might impact the transportation network structure by decreasing sea transport and the number of seaports used. This might lead to a further increase in land-based hinterland transport.     

集装箱枢纽港的成长模式探讨

港口(码头)达到满负荷营运通常需要5年以上的时间。一般说来,港口越大,其成长速度就越快。那些率先取得竞争优势的港口能够成功地成为地区性枢纽港,而那些不能率先取得足够货运量的港口往往会成为中小型的支线港口。只有某些具备适当前提条件的港口才能成为地区性集装箱枢纽港。此外,港口要成为地区枢纽港,还需具备地理位置、硬件和软件方面的条件。