不确定性在动态船队规划模型研究中的应用

通过分析传统船队规划问题,提出了利用鲁棒优化来建立不确定条件船队规划模型,在验证模型有效性时将已知概率的情景结合描述需求的不确定性,最后通过与需求确定情况相比较,说明本文的设计使得船队规划具有模型和解双重鲁棒性。     

Strategic fleet size planning for maritime refrigerated containers

In the present economic climate, it is often the case that profits can only be improved, or for that matter maintained, by improving efficiency and cutting costs. This is particularly notorious in the shipping business, where it has been seen that the competition is getting tougher among carriers, thus alliances and partnerships are resulting for cost effective services in recent years. In this scenario, effective planning methods are important not only for strategic but also operating tasks, covering their entire transportation systems. Container fleet size planning is an important part of the strategy of any shipping line. This paper addresses the problem of fleet size planning for refrigerated containers, to achieve cost-effective services in a competitive maritime shipping market. An analytical model is first discussed to determine the optimal size of an own dry container fleet. Then, this is extended for an own refrigerated container fleet, which is the case when an extremely unbalanced trade represents one of the major investment decisions to be taken by liner operators. Next, a simulation model is developed for fleet sizing in a more practical situation and, by using this, various scenarios are analysed to determine the most convenient composition of refrigerated fleet between own and leased containers for the transpacific cargo trade.     

一种混合优化的全局路径规划算法

针对全局路径规划研究中遗传算法存在搜索范围广而导致收敛速度慢的问题,本文提出一种混合优化的全局路径规划方法,完成对图像读取、处理后使用A*算法预处理缩小可行区域从而提高收敛速度。所提出的混合优化规划方法主要优化遗传算法的初始种群,在不影响最终路线的情况下,缩小初始种群的搜索范围,提高算法进行全局路径规划的速度,快速有效的规划出全局路线。另外本文给出一种评价体系对规划结果进行定量的避障评价,评价结果能够以数值形式对规划结果进行综合评价,评价结果显示通过混合优化算法规划出的路径具有更佳的安全性。     

虚拟目标算法在舰队协作中的应用

在海上军事领域,对上空导弹的精确定位﹑跟踪及打击是舰船制导领域重要的研究方向。同时,由于定位跟踪的目标有多个,需要舰队间协作,进行航路规划对多弹协同的弹道进行预测,其本质是一个多目标规划非线性问题。虚拟目标算法采用二维建模,多弹的路径规划引入条件约束,是解决弹道路径定位跟踪的有效算法。本文在分析海上导弹飞行能力﹑路径约束条件的基础上,利用虚拟算法设计导弹多目标的跟踪算法,最后给出了仿真结果。     

Multi-period liner ship fleet planning with dependent uncertain container shipment demand

This paper deals with a realistic multi-period liner ship fleet planning problem by incorporating stochastic dependency of the random and period-dependent container shipment demand. This problem is formulated as a multi-period stochastic programming model with a sequence of interrelated two-stage stochastic programming (2SSP) problems characterized ship fleet planning in each single period. A solution method integrating dual decomposition and Lagrangian relaxation method is designed for solving the developed model. Numerical experiments are carried out to assess applicability and performance of the proposed model and solution algorithm. The results further demonstrate importance of stochastic dependence of the uncertain container shipment demand.     

混合粒子群优化算法求解船队规划非线性模型研究

船队规划是非常复杂的决策,会受到很多因素的影响,客观、科学的得到优化结果非常重要。本文在线性模型的基础上,考虑船舶航速,并将船舶航行时间、成本等因素作为约束条件建立船队规划非线性模型,然后通过混合粒子群优化算法进行模型求解,最后进行仿真实验。实验结果表明,本文算法能够合理的规划船舶发展,并且船舶的限制率低。     

舰载无人机自动着舰动力学建模及控制算法

无人机在各个领域的应用已经越来越广泛。相比起传统的飞机,无人机不仅制造成本低,而且能够完成一些传统飞机无法完成的任务,比如远程侦测和军事打击等。但是无人机的发展和更大规模的应用仍然受到起飞和着舰技术的限制。自主轮式是未来发展的主要方向,此种方式的关键是自动控制算法的先进性和精确性。本文将在自主轮式的基础上,建立无人机起飞和着舰的数学模型,然后充分研究其动力学特性和控制算法。     

A dynamic model for marginal cost pricing of port infrastructures

ABSTRACT

A dynamic model for marginal cost pricing of port infrastructures links costs to system performance by combining a power-law function with time-dependent queueing analysis. Additionally, the model incorporates the marginal cost of capacity, including the effects of economies of scale. This allows the calculation of the marginal cost price under a dynamic framework. The model accounts for nonlinear behaviour of port demand, which is sensitive to price and service levels. The effects over time of cost and service levels on the port’s operational performance are quantified. The proposed model allows determining the optimal timing for capacity investment. The model is a starting point for the application of marginal cost pricing to ports. However, for practical application of such pricing method it is necessary to apply a system’s approach, as productivity and costs must be assessed at the terminal’s component level. This should allow the derivation of a marginal cost function at the terminal’s component level.     

顶推船队安全过弯的引航模型研究

根据船队在弯曲航段的运动特征，分析了船队过弯曲航道的数学模型；结合实船试验对模型进行了论证，得出船队过弯曲航道的一般规律。     

基于雷达网的舰艇编队作战能力评估模型

舰艇编队雷达网的作战能力很大程度上影响了编队的作战效能.利用定性和定量分析相结合的方法分析了影响舰艇编队雷达网作战能力的因素,建立了基于雷达网作战能力的编队综合作战能力指数模型.仿真结果表明,所建立的指数模型能反映编队装备体系效能与编队雷达网之间的关系,通过仿真计算几种舰艇编队编成模式下的综合作战能力指数,选择最优的编成模式.该模型对于辅助指挥员进行科学预测,合理编成编队,选择较好的配置方案,具有较好的指导意义.     

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.     

打造世界级油运"旗舰"--中远发展VLCC船队纪略

2001年,九届全国人大四次会议首次正式提出实施国家石油战略.2003年,十届全国人大会议审议了"关于我国政府应加快石油战略储备加强国家石油安全的提案",与会代表一致认为,我国要在21世纪与世界石油大国形成"制人而不制于人"的战略格局,加快石油战略储备步伐,建立一支海上油运"国家队"已成当务之急.     

Sea-going labour and Greek owned fleet: a major aspect of fleet competitiveness

This analysis aims to examine the current picture of maritime manpower in the Greek registered and owned fleet, as it has been formed during the post-war years. This objective entails the analysis of the current supply and demand for seafarers, the estimation of any shortfalls and their confrontation. Moreover, this study further investigates the contributory factors of the present employment trends, which simultaneously constitute special problems of the sea manpower of the Greek owned fleet and attempt some recommendations. In the context of the above mentioned objective, this analysis emphasizes issues such as recruitment, marine education and wastage. Furthermore, special consideration is given to the significance of labour costs for the development of the Greek owned fleet, particularly to subjects such as the various ways of reducing manning costs and their repercussions on the employment of Greek seamen. Finally, this analysis examines the trends of the state shipping policy concerning labour issues and proceeds to some recommendations.     

中国油运船队的战略选择——访大连远洋运输公司副总经理李玉平

目前,中国已成为全球第二大石油消费国和第三大石油进口国。进口原油中,有50%来自中东,22%来自非洲,12%来自东南亚。而且中国从这三个地区进口石油,不仅路途遥远,而且全部依赖海运。那么,如何才能建立起一支担负国家使命的油运船队?"国油国运"与油轮船队的国际化之间究竟是一种什么关系?大连远洋运输公司副总经理李玉平在接受本刊专访时,对此作了详细的阐释。     

反舰导弹轨迹规划算法研究与仿真

为实现对某舰载导弹的轨迹最优化设计,建立发射架动力学模型,并将其与轨迹优化模型相结合,得到导弹一体化的轨迹优化模型。采用Matlab软件对上述模型进行编程计算,得到发射架动态跟踪轨迹。计算结果表明,导弹在跟踪动态飞行攻击目标时,液压缸伸缩位移变化平顺,速度与加速度变化不大,并没有出现强烈的冲击现象,能够保证导弹外弹道的稳定性,提高其轨迹精度。     

基于改进A*算法的无人船路径规划研究

针对无人船路径规划过程中存在的规划结果所占内存较大、耗费时间较长、有较大概率生成"死区"的问题,提出基于改进A*算法的无人船路径规划方法.选取栅格法构建无人船行驶环境模型,采用A*算法确定代价函数,判断代价大小,以代价最小的节点作为下一个轨迹点,由此获取最优无人船行驶路径.为改进A*算法,利用无人船转弯半径下限、路径长...     

发展我国植物油船船队的难点及对策

从我国植物油进口的刚性需求、植物油船短缺影响运输发展及国家食用油安全角度阐述我国发展植物油船船队的必要性,指出发展植物油船船队的难点,提出发展我国植物油船船队对策：（1）加强货源控制;（2）与国有化学品航运企业合作,打造精品航线;（3）进行技术创新,建造专用植物油船.     

船舶物流路径规划的数学模型构建及求解

船舶物流路径规划的研究具有十分重要的经济价值,当前船舶物流路径规划方法无法找到最优的船舶物流路径规划方案,使得船舶物流运输的成本过高,为此本文设计了基于蚁群算法和粒子群算法的船舶物流路径规划方法。首先分析船舶物流路径规划研究的历史,建立船舶物流路径规划的数学模型,然后采用粒子群算法对船舶物流路径规划的数学模型进行求解,找到有效的船舶物流路径规划方案集合,并在此基础上采用蚁群算法对船舶物流路径规划方案集合进行搜索,找到最优的船舶物流路径规划方案,最后与单一蚁群算法、粒子群算法进行了船舶物流路径规划问题求解的仿真实验。本文方法避免了单一蚁群算法、粒子群算法求解速度慢,难以找到最优船舶物流路径规划方案不足,得到的船舶物流路径规划方案可以帮助企业节约物流运输成本。     

多功能挖泥配套辅助船舶的研究

疏浚作业是一项复杂的系统工程 ,如何合理配置其各组成单元 ,是一项很值得研究的工作。在分析系统组成的基础上 ,从减少挖泥船队投资规模、提高作业管理效率的角度 ,提出了吸扬式挖泥船队的编队方式 ,即挖泥船 (含水上排泥管系 ) +宿舍船 +多功能辅助船组成的挖泥船队 ,实现了吸扬式挖泥船队的最简化配置 ,并进一步就多功能辅助船舶的设计研究作了有益的探讨