Prediction of the forces acting on container carriers in muddy navigation areas using a fluidization parameter

To assess the safety of navigation in muddy areas, a comprehensive captive manoeuvring model test program was executed. Based on the results of this experimental program, a four-quadrant manoeuvring model was built with a separate set of coefficients for each combination of under-keel clearance and mud layer characteristics. The disadvantage of this model is that only conditions corresponding with the experimental ones can be simulated. A more consolidated mathematical model was needed. This was achieved with the introduction of a fluidization parameter that determines the corresponding hydrodynamically equivalent depth above a solid bottom. As a result, the under-keel clearance dependency of a given mathematical manoeuvring model can be reformulated in such way that the effect of any realistic muddy condition is included. In this article, the modelling of the hull forces, the propeller thrust and torque, and the forces acting on the rudder will be discussed.     

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.     

Optimal management of human resources in transhipment container ports

Human resources allocation plays a key role in transhipment maritime container terminals to achieve high levels of productivity and provide high quality services to shipping companies. The deep interest of container terminals in this issue can be supported by optimization methods. In this work, an optimization model is proposed to determine the optimal daily allocation of crane operators and trailer drivers. Different requirements are taken into account for permanent staff, external workers and personnel shortfall. Since workforce undermanning is a crucial factor for both shipping companies and container terminals, we aim to show that personnel shortfalls and operation delays can be significantly reduced if the model encompasses a longer-than-1-day planning horizon in a rolling horizon fashion.     

船舶轴带发电机系统建模与计算机仿真研究

以2700TEU的某集装箱船为母型,根据远洋船舶轴带发电机系统的工作原理和结构组成,建立系统各主要组成环节的数学模型,并利用MINIS通用仿真支撑平台实现了整个船舶轴带发电机系统的仿真。所建立的数学模型可以仿真轴带发电机系统的正常工作过程和过渡过程,达到了较高的仿真精度。     

洋山港集装箱滚装渡船船型方案探讨

针对洋山港建成国际集装箱深水港后的集装箱集疏运问题,及该航线特点,提出一种滚装渡船方案,从布置地位、性能要求等方面展开,对这种船型进行分析计算。结果表明：通过这种船型集疏运集装箱的过海成本较低。     

集装箱船配载问题的粒子群算法研究

针对集装箱船配载优化中的Bay位优选问题,提出以倒箱量、重心横向偏移和初稳性高为目标,以箱位与Bay位的一致和Bay位重量为约束条件的数学模型,提出一种多目标离散粒子群算法(MODPSO)求解之,得到该算法优化后的Pareto解集和Pareto解迭代过程中的变化趋势图,为集装箱船配载问题提供多种方案以供备选,从而达到在提高集装箱船装载效率、节约装载成本和时间、使集装箱船获得稳定航行状态等目标间取得更好平衡的目的。     

A slot reallocation model for containership schedule adjustment

Ship slot capacity is the main sale resource of container shipping lines. However, shipping lines often encounter situations, such as serious ship delays, that require adjustments of shipping schedules, causing the original delivery plans of some consignments to be altered. This study proposes an integer programming model for slot reallocation planning, based on a given adjusted schedule. Decisions regarding empty container repositioning are also examined. This model aims to maximise a company’s benefits from deliveries of consignments and movements of empty containers. Available slots are subject to port rotation changes, allowable port handlings and ship capacity. A case study of a deep ocean loop demonstrates optimal slot reallocation, and empty container repositioning is used for illustrative purposes. The reallocation characteristics due to benefit items and the model’s applicability to large-scale examples are discussed.     

船舶轴带发电机系统的建模与仿真

以1700TEU的某集装箱船为母型，研究了远洋船舶轴带发电机系统的工作原理并对其进行数学建模及仿真，所建立的数学模型可以仿真轴带发电机系统的正常工作过程及过渡过程的工况，达到了较高的稳态和动态仿真精度。     

环抱式港区建设期泥沙回淤数值模拟研究

在淤泥质海岸建港,泥沙回淤是必须考虑的首要问题。文中应用波流共同作用下的大范围泥沙数学模型,模拟计算了连云港港徐圩港区建设期不同布置方案下的泥沙回淤情况。研究结果表明：徐圩港区在建设期的回淤中,内航道所占比重较大,主要与港区水域面积有关。因此,在环抱式港区的建设过程中,应尽可能早地实施港区内的规划围垦项目,以达到防淤减淤的目的。     

基于多种群萤火虫算法的集装箱船结构优化

针对集装箱船结构优化问题,依据CCS规范建立以集装箱船舯剖面面积最小为优化目标,板厚、型材横截面积为离散设计变量的优化数学模型。提出一种多种群萤火虫算法,各种群设置不同的参数,提高搜索区域,多子群并行寻优、子群主群协作寻优提高算法寻优性能,对所建模型进行优化计算。优化算例表明,所提出的多种群萤火虫算法比标准萤火虫算法可以更快的收敛得到最优解,在满足所有约束条件情况下,集装箱船舯剖面面积最小约13.2%,验证了多种群萤火虫算法应用于集装箱船结构优化的有效性。     

基于多智能体仿真的集装箱港口作业效率研究

集装箱港口生产作业系统是复杂的离散事件系统,数学建模方法难以构建针对整个系统的模型,而基于过程的仿真模型通常缺乏对设备调度的灵活性。为准确描述我国集装箱港口的作业流程,分析内卡配置数量对港口作业效率的影响,提出了基于事件驱动的集装箱港口多智能体(Multi-Agent)仿真模型。仿真结果表明:岸桥平均装卸效率(GCR)随着内卡数量的增加先急剧增加后缓慢增加,船舶平均等待时间(AWT)和平均在泊时间(AST)与岸桥平均装卸效率呈明显负相关关系。     

基于最小偏差法的集装箱船船型优化

根据最小偏差法原理，建立了西江中小型集装箱船主要要素的多目标优化数学模型，运用遗传算法对该模型进行多目标优化。算例结果表明所建立的模型可行，能找到全局最优解，并在最优解基础上设计了实船。     

沿海内贸集装箱班轮航线优化研究

随着沿海内贸集装箱运输市场的快速发展,各大班轮公司如何把船舶安排到最佳航线上,使有限的船舶资源创造最大的经济利益,成为各大公司研究的课题。根据沿海几大干线港口之间的运量需求,建立非线性规划与整数规划相结合的混合模型,选择典型航线建立运输网络,并对其进行优化。该数学模型可应用于解决我国沿海内贸集装箱船舶运输航线配置问题,进而实现利润最大。     

Modelling and optimisation of online container stacking with operational constraints

Container transportation plays a critical role in the global shipping network and container terminals need to improve their operations to increase efficiency. Storage yard of a container terminal is a temporary area where the containers stay until they are shipped to their next destination. We concentrate on increasing the efficiency of the storage yard by developing online stacking policies for each incoming container. An unproductive move of a container, performed to reach another container stored underneath, is called reshuffling. The objective in container stacking problem is to minimise the number of reshuffles, thereby increasing the efficiency of terminal operations. Additional weight-related operational constraints bring additional complexity to the online stacking decisions. We propose a mathematical model for the optimal online assignment of an incoming export, transit, import or empty container. We also propose an optimal online stacking policy and compare it with a random policy through simulation. Additionally, lower bounds for the performance measures are obtained through simulation by relaxing the operational constraints of the problem in a third stacking policy. We present and discuss the computational results in terms of four main performance measures.     

大深度潜器潜浮运动的建模与仿真

大深度潜器潜浮运动是一种超大攻角运动,它无法用常规水中物体的运动数学模型描述.文章给出了一种新型数学模型来描述这种大深度潜器的潜浮运动,并论述了结合现代仿真技术的应用,使潜水器所受流体动力的数学描述变得便捷、可行.此外,文中还研究了在大深度环境下,潜器潜浮运动时,潜器所受浮力和重力随深度变化的数学描述.上述理论已应用于有关潜器潜浮运动系统的设计.     

偏好泊位约束下的集装箱港口离散泊位分配问题*

在集装箱码头中,泊位调度系统是影响码头作业调度的重要环节,而泊位分配问题又是其首要问题。为了揭示 泊位偏好对泊位分配问题的影响,重点从集装箱码头泊位分配问题和基于船舶泊位偏好问题两方面展开研究,为对泊位分 配和泊位偏好进行协同优化配置,建立泊位偏好约束下的多目标混合整数数学模型。并且采用CPLEX进行求解。通过算例 说明模型的有效性,并通过实验分析船舶对泊位的偏好的影响。结果对港口具有的实际应用价值,拓展了对离散型靠泊计 划的研究。     

深层搅拌法加固应天河套闸软基工程

太湖应天河套闸地基土性复杂，淤泥质粘土中富含有机质，土壤呈酸性。通过深层搅拌法加固套闸软基工程实例，分析了此条件下水泥土强度标准值的影响因素和取值方法，介绍了施工工艺和注意事项。工程实例表明，采取适当改进措施，深层搅拌法加固淤泥质酸性土可以达到预期的强度。     

基于MATLAB集装箱起重机防摇系统仿真

建立了一种新型集装箱堆场起重机防摇系统数学模型,对八绳防摇系统进行受力分析,通过等效简化建立了广义坐标下双起升场桥的载荷摇摆动力学数学模型,该模型能客观地再现八绳防摇系统的运行情况.同时在MATLAB的SIMULINK环境下对此模型进行了动态仿真研究,与普通集装箱场桥模型的比较表明,八绳防摇系统的摇摆幅度明显减小,具有较大的优越性.     

Estimation of CO2 reduction for Japanese domestic container transportation based on mathematical models

This research discusses domestic feeder container transportation connected with international trades in Japan. Optimal round trip courses of container ship fleet from the perspective of CO₂ emission reduction are calculated and analyzed to obtain basic knowledge about CO₂ emission reduction in the container feeder transportation system. Specifically, based on the weekly origin–destination (OD) data at a hub port (Kobe) and other related transportation data, the ship routes are designed by employing a mathematical modeling approach. First, a mixed integer programming model is formulated and solved by using an optimization software that employs branch and bound algorithm. The objective function of the model is to minimize the CO₂ emission subject to necessary (and partially simplified) constraints. The model is then tested on various types of ships with different speed and capacity. Moreover, it is also tested on various waiting times at hub port to investigate the effect in CO₂ emission of the designated fleet. Both the assessment method of container feeder transportation and the transportation’s basic insights in view of CO₂ emission are shown through the analysis.     

集装箱船舶大型化现状与未来发展预测

美国次贷危机对全球实体经济影响的加深以及国际石油价格的剧烈变化短期内可能改变集装箱船舶大型化的趋势,但是从长期看,全球集装箱船舶大型化的趋势仍将继续。本文利用相关数据,分析预测未来集装箱船舶大型化的发展状况。