Optimisation and heuristic approaches for assigning inbound containers to outbound carriers

Due to economical and/or geographical constraints, most of the time overseas containers cannot be directly shipped to their destinations. These containers visit transhipment ports where they are first unloaded and temporarily stored and then loaded onto smaller vessels (feeders) to be transported to their final destinations. The assignment of these containers to outbound vessels necessitates several factors to be taken into account simultaneously. In this paper, we develop a mathematical model to reflect multiple objectives with priorities and to assign these containers to different vessels at the transit container port terminal. Although we solve a single-objective (with the weighted sum of objectives) mathematical model to optimality, we also propose two heuristic approaches to solve this complex problem for a transit agency. The first heuristic is shipment based and has four variants differing in how the opportunity costs of the assignments are calculated. The second greedy heuristic is trip based, where the goal is to maximise the capacity utilisation of the vessels. The heuristics return very promising solutions in ignorable computational times. We also provide real-life cases and present our conclusions.     

混合蚁群算法求解集装箱箱位分配问题

集装箱船配载过程中的重要环节是合理的箱位分配,它对保证集装箱船装载后的航行性能及其码头装箱效率有重要的影响.随着集装箱船的大型化及待装船箱量的增加,该问题的求解较为困难.结合集装箱船配载中箱位分配的实际操作特点,提出了利用与禁忌算法相结合的混合蚁群算法来求解集装箱的箱位分配问题.仿真模拟试验表明该算法能够在不影响装箱难度的同时,大幅提高集装箱装船后船舶的航行性能.     

集装箱船冷藏集装箱水冷却系统设计

支线型集装箱船在布置数量较多的水冷式冷藏集装箱情况下,如何保证冷藏集装箱水冷却流量平衡分配并确保冷藏集装箱冷藏效果成为设计的关键点。文章结合某2200标准箱集装箱船实例,介绍了冷藏集装箱船的水冷却系统的设计、注意事项及试验方法。为今后大中型集装箱船冷藏箱冷却水系统应用提供设计依据。     

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.     

Model and algorithm for container ship stowage planning based on bin-packing problem

In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage planning problem increases due to its multi-ports nature. This problem is NP-hard problem. In order to reduce the computational complexity, the problem is decomposed into two sub-problems in this paper. First, container ship stowage problem （CSSP） is regarded as “packing problem”, ship-bays on the board of vessel are regarded as bins, the number of slots at each bay are taken as capacities of bins, and containers with different characteristics （homogeneous containers group） are treated as items packed. At this stage, there are two objective functions, one is to minimize the number of bays packed by containers and the other is to minimize the number of overstows. Secondly, containers assigned to each bays at first stage are allocate to special slot, the objective functions are to minimize the metacentric height, heel and overstows. The taboo search heuristics algorithm are used to solve the subproblem. The main focus of this paper is on the first subproblem. A case certifies the feasibility of the model and algorithm.     

Empty container reposition planning for intra-Asia liner shipping

This paper addresses empty container reposition planning by plainly considering safety stock management and geographical regions. This plan could avoid drawback in practice which collects mass empty containers at a port then repositions most empty containers at a time. Empty containers occupy slots on vessel and the liner shipping company loses chance to yield freight revenue. The problem is drawn up as a two-stage problem. The upper problem is identified to estimate the empty container stock at each port and the lower problem models the empty container reposition planning with shipping service network as the Transportation Problem by Liner Problem. We looked at case studies of the Taiwan Liner Shipping Company to show the application of the proposed model. The results show the model provides optimization techniques to minimize cost of empty container reposition and to provide an evidence to adjust strategy of restructuring the shipping service network.     

基于模拟减少集装箱船待港时间的实用方法(英文)

The main challenge for container ports is the planning required for berthing container ships while docked in port.Growth of containerization is creating problems for ports and container terminals as they reach their capacity limits of various resources which increasingly leads to traffic and port congestion.Good planning and management of container terminal operations reduces waiting time for liner ships.Reducing the waiting time improves the terminal’s productivity and decreases the port difficulties.Two important keys to reducing waiting time with berth allocation are determining suitable access channel depths and increasing the number of berths which in this paper are studied and analyzed as practical solutions.Simulation based analysis is the only way to understand how various resources interact with each other and how they are affected in the berthing time of ships.We used the Enterprise Dynamics software to produce simulation models due to the complexity and nature of the problems.We further present case study for berth allocation simulation of the biggest container terminal in Iran and the optimum access channel depth and the number of berths are obtained from simulation results.The results show a significant reduction in the waiting time for container ships and can be useful for major functions in operations and development of container ship terminals.     

Weekly container delivery patterns in liner shipping planning models

This paper addresses a fundamental question related to nearly all container liner shipping planning models: whether the implicit assumption of identical container delivery pattern every week is valid in a situation of identical shipping services and identical cargo demand every week. We prove that when the number of containers transported from one port to the next is formulated as a continuous variable, the resulting mathematical model with an identical container delivery pattern is equivalent to the model with general container delivery patterns which can be different in different weeks. When the number of containers transported is formulated as an integer variable, the model with an identical container delivery pattern is not equivalent to the model with general container delivery patterns. However, the difference between the optimal objective values of the two models is negligible for practical applications. In sum, little, if not nothing, is lost by assuming an identical container delivery pattern in liner shipping planning models.     

重箱堆场地下管网施工

重箱堆场作为集装箱码头后方的存储腹地，对集装箱的储运起着十分重要的作用。文章表明，在重箱堆场施工过程中，对地下管网施工，如何选择有效的施工方法，安排控制好相关工序的衔接，是保证重箱堆场工程有条不紊进行，确保施工进度与质量的重中之重。     

基于多目标混沌云粒子群算法的泊位-岸桥分配研究

为了提高集装箱港口泊位-岸桥分配效果和优化效率,以集卡运距和船舶在港时间最小为优化目标,建立了多目标离散泊位-岸桥分配模型,利用混沌云粒子群算法对泊位-岸桥分配模型进行求解,开发了粒子可行-整数化处理模块,内嵌于混沌云粒子群算法进化中,制定了粒子编码规则,设计了多目标函数的粒子历史极值和全局极值的计算方法,提出了基于混沌云粒子群优化算法求解多目标离散泊位-岸桥分配模型的新方法,数值算例结果证明了该模型和算法的可行性和实用性。     

船用冷藏集装箱技术中国专利综述

通过检索中国专利库，找到冷藏集装箱的全部539个中国专利申请，研究分析其中涉及船用的142个发明专利申请和5个实用新型专利的申请，分别设计并提出专利权人分析、设计并提出专利指数D1、D2、D3、D4和TD1专利时域分析、FD专利频域指数分析、TD2专利时域趋势分析，推导出了船用冷藏集装箱发明时域图，并且分析了重点专利个案。分析发现目前我国在船用冷藏集装箱行业在单一创新和融合创新情况下的存在的机遇与挑战，结合这些分析和对未来发展趋势的预估，提出了一种船用冷藏集装箱集群外部测控的设计思路。     

振动碾压与降水联合法在集装箱空箱堆场软基处理中的应用

结合上海港外高桥二期空箱堆场的地质条件和使用要求,提出振动碾压与降水联合的方法处理软地基,并采用土工格栅方法减小堆场地基的不均匀沉降,实际工程测试结果表明该方案能满足集装箱堆场自动化机械对场地沉降的要求。     

连续泊位调度与岸桥配置协同优化

连续泊位调度与岸桥配置协同优化是集装箱码头提升竞争力的关键因素.针对该问题构建一个混合整数规划模型,以构造算法为核心,通过调整船舶的分配次序,设计了一个新的启发式算法.通过VB6.0软件编程,进行了四组大规模仿真算例实验,结果显示60%的算例在新算法下可获得更优的解,平均改进7.37%,证明了模型和算法的有效性.     

Optimal reefer slot conversion for container freight transportation

Given a fleet of container ships of varying capacity, a cost-efficient approach for improving fleet utilization and reducing the number of delayed containers is to optimize the sequence of container ships in a given string, a problem which belongs to the large ship-deployment class. A string sequence with ‘uniformly’ distributed ship capacity is more likely to accommodate a random container shipment demand. The number of one’s total ship slots acts as a gauge of the capacity of the container ships. Meanwhile, there are two types of ship slots: dry slots and reefer slots. A dry slot only accommodates a dry container, while a reefer slot can accommodate either a dry or a reefer container. The numbers of dry and reefer slots for ships in a string are different. Therefore, in this study, we propose a model that considers both dry and reefer slots and use it to elucidate the optimal ship-deployment sequence. The objective is to minimize the delay of dry and reefer containers when the demand is uncertain. Furthermore, based on the optimal sequence deduced, the study also investigates the need to convert some dry slots to reefer slots for the container ships.     

Analysis of the continuous berth allocation problem in container ports using a genetic algorithm

The optimal usage of berths plays a key role in raising the efficiency of container terminals. The berth allocation problem in a container terminal is defined as the feasible allocation of berths to incoming ships such that the total time that elapses between the arrival of the ships to their exit from their berths is minimized. In the transportation literature, the latter problem is usually formulated as a mixed integer programming model. Optimization methods, like the branch and bound algorithm, are efficient ways to solve this model but become absolutely unusable when the size of the problem increases. An advanced search method such as GA may be suited to such a situation. In this paper, a genetic-based algorithm is proposed for the problem. Computational results for two test problems (a small and a large-sized problem) are also presented. The results from the small test are also compared with the results obtained from the branch and bound algorithm.     

Evaluating seaport operation and capacity analysis—preliminary methodology

The marine terminal in general and the container terminal in particular is the physical link between ocean and land modes of transportation. Port capacity is commonly defined as the amount of cargo that can be handled by a port per time period, usually a year. For containers it is the number of processed containers per year, for bulk cargo-tons or pallets per year and for Ro-Ro cargoes-autos per year. As the number of ships and the amount of cargo passing through the port increase, a point is reached at which some elements of the port system are functioning near or beyond their maximum productivity rate. The concept that should direct the terminal capacity analysis is controlled by the terminal activity that determines the lowest capacity rate per unit of time, during one cycle of operation. Four performance measures are introduced in order to establish a recommended methodology that quantifies the port's quality of operation and also functions as a tool for decision makers to justify a required investment. The methodology should become a standard that might turn into a requirement for examining every port's level of service.     

Experimental and numerical investigation of lashing bridge and container stack dynamics using a scaled model test

Previously reported container losses were generally attributed to extremely violent motions of containerships due to adverse weather conditions. However, most existing specifications or standards adopted for containers and lashing equipment meet the requirement of static conditions. Hence, further researches on safer container shipping under heavy sea states are required. Consequently, an experimental study method is proposed to measure the dynamic response of 1/10 scaled lashing bridge and container stack. The scaled model of the lashing bridge is constructed based on the similarity theory. Based on two dimensionless numbers, Froude's number and Cauchy's number, eleven container scaled models are employed. A series of experiments with controlled parameters are performed using a three-degrees shaking table (roll, pitch, heave) to present sufficient data to verify the effectiveness of the numerical model. The results of experiments, numerical simulations and calculations of the VERISTAR procedure (developed according to the BV rule) are compared. This study aimed to explore the mechanical behavior of the lashing bridge and container stack under predetermined driving excitations (roll and pitch) which simulated heavy sea states. According to the results, the model can predict conditions similar to real situations of the lashing bridge and container stacks while storages on the weather deck.     

Next generation mega container ports: implications of traffic composition on sea space demand

ABSTRACT

Demand for sea space brought about by increasing container-shipping traffic has important implications on how this space is managed and used. This is particularly important given the long-term nature, high-asset specificity, high- opportunity cost of investment, and significant economic impact of container port activity on a locality. The challenge is especially pressing for ports, which are facing constraints in seaside capacity where container traffic also has to co-exist with the needs of other types of ship traffic. This challenge is likely be multiplied for next generation container ports, which are expected to handle even larger traffic volumes. These ports are also likely to face competing sea space demands from other economic and social activities especially when they are concurrently major confluences of trade, logistics, and urban populations. This is the first research to investigate in detail the impact and importance of investigating sea space requirements from the perspective of cargo traffic composition and ship capacity. Results show that transshipment containers can generate much higher demand for sea space due to the higher volume of shipping capacity that accompanies such traffic. Sustainability issues and managerial and policy implications pertaining to the development of next generation container ports are provided.     

中小型集装箱船方形系数估算公式

在所收集的近百艘中小型集装箱船船型资料的基础上,作者对集装箱船方形系数与载箱数、傅汝德数的关系作了分析,并应用计算机回归得到一个能反映集装箱船特征的方形系数估算公式。此公式可应用于集装箱船的初步设计阶段。     

集装箱智能道口箱号识别系统中的字符识别技术

文章介绍的模式识别与结构分析组合及箱号校对的识别技术,很好地解决了集装箱智能道口箱号识别中的字符不完全在一个平面上与箱号横竖排列不定等问题。结果表明,这种方案能提高箱号识别的准确性及效率。