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船队规划的动态模型与算法 总被引:1,自引:0,他引:1
通过分析船队规划线性模型在实际应用中的优缺点,本文提出了用线性规划与动态规划相结合的算法求解连续若干年间船队最佳发展策略和最优航线配船问题。本方法不仅保留了船队规划线性模型的主要优点,节省计算时间,而且使规划结果中每年每种船型的造(购)船数量一定取整数值,更符合实际使用要求。文中给出了这一动态规划数学模型及其算法,并列出了一个计算实例。 相似文献
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分析航运公司船队规划的特点,考虑船舶技术经济指标随船龄的变化和市场的不确定性,建立基于不确定性的动态船队规划模型,并考虑到不确定性规划求解的复杂性,把带有模糊、随机参数的机会约束转化为它的清晰等价类并根据船队规划问题具有大规模、离散性和整数性等特点,采用离散粒子群算法进行求解,通过实例说明该方法的可行性. 相似文献
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不确定动态船队规划的数学模型研究 总被引:4,自引:1,他引:3
针对目前船队规划存在的不足(①没有考虑船舶的技术经济指标随船龄的变化;②在考虑市场不确定性因素时只对其作定性分析或敏感性分析而没有将营运参数作为不确定性函数考虑),重点研究了基于不确定性的动态船队规划模型,同时考虑到不确定性规划求解的复杂性.根据航运企业一定的满意度将模型转化为带有模糊、随机参数的机会约束数学模型并进一步转化为它的清晰等价类再进行船队规划求解.使其数学模型符合航运市场的特点,对航运企业投资决定有重大意义. 相似文献
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文中对船舶支线运输问题进行了研究,给出了船舶支线运输的界定,并且对船舶支线运输的特点进行了分析。针对单航次单喂给港的运输方式,一条船可以兼顾多条航线运输,建立了综合的整数规划模型,以船队总运输成本最低作为目标函数,系统的考虑了港口及航线条件约束,时间约束,求解后便同时解决了包括航线选择,船队组建,航线配船等问题。该模型简单实用,弥补了当前支线运输船队规划的不足,更好的满足实际需求。通过LNG支线运输船队规划实例验证,结果稳定可靠。 相似文献
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一、船队规划的原则与影响因素 1.船队规划 所谓船队规划就是根据航运市场研究的结果,依据一定的原则和方法,对规划期内船舶的购置、使用、更新和处理所作出的系统动态安排。其重点是确定船队 相似文献
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A dynamic model and algorithm for fleet planning 总被引:1,自引:0,他引:1
By analysing the merits and demerits of the existing linear model for fleet planning, this paper presents an algorithm which combines the linear programming technique with that of dynamic programming to improve the solution to linear model for fleet planning. This new approach has not only the merits that the linear model for fleet planning has, but also the merit of saving computing time. The numbers of ships newly added into the fleet every year are always integers in the final optimal solution. The last feature of the solution directly meets the requirements of practical application. Both the mathematical model of the dynamic fleet planning and its algorithm are put forward in this paper. A calculating example is also given. 相似文献
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舰船编队的电磁干扰(EMI)分析预测比单舰情况复杂,这是由于编队中各舰相对运动产生的不定因素对预测结果会产生一定的影响。具体讨论了编队中舰舰间距离、方位和雷达天线转动等不定因素的扰动对耦合度的影响,提出了在舰船编队电磁兼容性分析预测中应采用统计分析技术。 相似文献
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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. 相似文献
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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. 相似文献
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介绍情景规划法的概念、特点、相对优势及其与传统规划法的区别,为优化企业资源配置,指导企业行动方向,为未来不确定的情景准备预案和应对情景所需的资源,提出情景规划法在航运企业战略规划中的应用步骤:确定规划目标;分析主要外部影响因素;构建情景矩阵;详尽描述每个情景;量化每个情景对企业的影响,阐明相应的战略对策。 相似文献