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1.
沈振 《中国水运》2010,(6):65-67
为准确预测上海水运和远洋货运量,更好地建设上海国际航运中心,文中通过对上海1999~2009年水运和远洋货运量的统计分析和研究,应用灰色系统中的GM(1,1)模型,建立了上海水运和远洋货运量预测模型,通过预测模型运行并与历史数据进行比较,确认预测模型准确度较高;最后以此预测模型对上海2012~2019年的水运和远洋货运量进行了预测。  相似文献   

2.
组合预测方法在我国公路货运量预测中的应用   总被引:2,自引:0,他引:2  
科学准确地预测公路货运量是制定公路网规划的基础。文中运用灰色Verhulst模型和一次指数平滑模型相结合的组合预测模型对我国的公路货运量进行预测。结果表明,组合预测模型能够提高我国公路货运量的预测精度。  相似文献   

3.
为寻求更高精度的预测方法预测长江经济带未来一段时间的集装箱需求量,从经济总量水平、产业结构、国际国内贸易发展等方面提取长江干线港口集装箱需求预测的主要影响因素,构建基于遗传算法-支持向量机(GA-SVM)的预测模型对长江干线港口集装箱需求量进行预测,提高货运量预测精确度。结果表明:此模型对长江干线港口集装箱需求量的预测具有较强的实用性,可为长江干线港口集装箱需求预测提供一种新的途径和方法。  相似文献   

4.
通过对重庆水运发展现状的研究,根据马尔科夫理论及灰色预测模型,将灰色GM模型与马尔科夫状态转移矩阵相结合,建立了预测重庆水运货运量的灰色马尔科夫模型,并通过实际预测发现,该模型的预测精度明显高于灰色预测模型的预测结果,并预测了2011—2012年重庆市水运货运量。  相似文献   

5.
通过对长三角地区水运货运量的分析和研究,应用灰色系统中的GM(1,1)模型及其残差周期修正方法,建立了经残差修正后的预测模型,通过运行预测模型并与原历史数据进行比较,确认预测模型准确度较高;最后以此预测模型对长三角地区2012—2019年的水运货运量进行了预测。  相似文献   

6.
港口物流量建模与预测是当前的研究热点,传统神经网络无法有效反映港口物流量的变化特点,使得港口物流量预测结果不可信,为了提高港口物流量预测的准确性,提出了遗传算法优化神经网络参数的港口物流量预测模型。首先对港口物流量建模与预测的研究进展进行分析,分析当前港口物流量预测模型的局限性,然后针对神经网络参数优化问题,引入遗传算法对其进行搜索,得到最优的神经网络模型,最后将优化后的神经网络模型引入到港口物流量建模与预测,并进行港口物流量预测的仿真分析。结果表明遗传算法优化神经网络的港口物流量预测准确性高,可以对港口物流量变化特点进行长时间分析,获得了比传统神经网络更优的港口物流量预测结果。  相似文献   

7.
采用BP神经网络建立了乌江银盘枢纽工程河段货运量的预测模型,并对货运量进行了实际预测,分析认为神经网络预测结果较戴尔斐法和GM(1,1)法更为合理。  相似文献   

8.
以某港口1997-2007年集装箱吞吐量为原始数据,建立了回归分析、3次指数平滑及灰色系统方法的港口集装箱吞吐量单项预测模型。鉴于单项预测模型的局限性,以误差平方和极小化为最优化准则,进行了多模型组合预测,并辅以实例进行分析和验证,通过误差的分析表明该模型能够改善预测精度,可以作为未来港口集装箱吞吐量预测的工具。  相似文献   

9.
通过多元回归、时间序列模型以及灰色预测模型,对青岛市的近20 a对外贸易总额和吞吐量进行分析预测。充分考虑与港口货物吞吐量相关的六种因素指标,构建多元回归方程,运用Eviews软件对各因素的数据进行处理,建立ARIMA模型并对提取的三个指标进行预测,从而对回归模型中的对外贸易进出口总额(因变量)进行总预测,以了解青岛港的运输需求量;采用灰色预测模型并运用MATLAB软件对青岛港的货物吞吐量预测,分析青岛港港口的运输承载力。运用数学模型对港口吞吐量进行科学的评价和预测,能为青岛港制定中长期发展战略提供基本依据,对港口的持续发展的具有一定的现实意义。  相似文献   

10.
组合预测模型在宁波港集装箱吞吐量预测中的应用   总被引:2,自引:0,他引:2  
港口吞吐量预测是港口规划过程中的关键环节,直接关系到港口规划的科学合理性。本文根据宁波港集装箱吞吐量的历史数据,建立了时间序列的三次指数平滑模型、灰色系统预测模型等单项预测模型。鉴于单项预测模型的局限性,提出了组合预测模型,采用线性规划的方法确定其最优组合的权重,并对宁波港集装箱吞吐量加以预测和分析。  相似文献   

11.
以杭嘉湖航道网改造工程为实例,采用敏感性分析和概率分析的方法,分别按改扩建项目和新建项目,探讨不同收费方式下内河航道工程的财务效益。研究结果表明,运量大的长湖申线有一定的财务效益,项目自身具有生存能力,但运量小的六平申线,财务效益差,投资决策应注重其社会效益。  相似文献   

12.
Logistics integration and network orientation in the port and maritime industry have redefined the functional role of ports in value chains and have generated new patterns of freight distribution and new approaches to port hierarchy. Existing models on the spatial and functional evolution of ports and port systems only partially fit into the new freight distribution paradigm. This paper aims to add to existing literature by introducing a port regionalization phase in port and port system development. It is demonstrated that the regionalization phase and associated hinterland concepts demand new approaches to port governance and a functional focus that goes beyond the traditional port perimeter.  相似文献   

13.
Port regionalization: towards a new phase in port development   总被引:7,自引:0,他引:7  
Logistics integration and network orientation in the port and maritime industry have redefined the functional role of ports in value chains and have generated new patterns of freight distribution and new approaches to port hierarchy. Existing models on the spatial and functional evolution of ports and port systems only partially fit into the new freight distribution paradigm. This paper aims to add to existing literature by introducing a port regionalization phase in port and port system development. It is demonstrated that the regionalization phase and associated hinterland concepts demand new approaches to port governance and a functional focus that goes beyond the traditional port perimeter.  相似文献   

14.
Spatial computable general equilibrium (SCGE) theory has been applied to an international trade model to evaluate tariff and fiscal policies of a country. Those models can not be applied for the evaluation of transport policies such as port development and tax/subsidy policy against transportation sectors, since they do not deal with ocean freight and ocean carriers explicitly in the model. Ocean freight often varies with the changes of competitive conditions and/or demand/ supply balances in the short run, while it should reflect the actual expenditure of the carriers in the long run. The model proposed here considers the profit maximization behaviour of ocean carriers, and deals with ocean freight explicitly. The model is applied to four major economic regions; Japan, USA, EU and Asia. A multi-level function composed of the Cobb-Douglas function is adopted to produce reliable parameters of the production function for many industries.  相似文献   

15.
Spatial computable general equilibrium (SCGE) theory has been applied to an international trade model to evaluate tariff and fiscal policies of a country. Those models can not be applied for the evaluation of transport policies such as port development and tax/subsidy policy against transportation sectors, since they do not deal with ocean freight and ocean carriers explicitly in the model. Ocean freight often varies with the changes of competitive conditions and/or demand/ supply balances in the short run, while it should reflect the actual expenditure of the carriers in the long run. The model proposed here considers the profit maximization behaviour of ocean carriers, and deals with ocean freight explicitly. The model is applied to four major economic regions; Japan, USA, EU and Asia. A multi-level function composed of the Cobb-Douglas function is adopted to produce reliable parameters of the production function for many industries.  相似文献   

16.
基于SD 仿真的广西北部湾港集疏运系统协调发展研究*   总被引:1,自引:0,他引:1  
为分析港口集疏运系统的行为特征和发展趋势,首先依据协同论等相关理论,对港口集疏运系统协调发展内涵进行了界定。其次以广西北部湾港口为研究对象,运用系统动力学的原理及仿真方法,在系统分析和因果反馈分析的基础上建立了港口集疏运协调发展的系统动力学模型,包括港口吞吐需求、吞吐能力、集疏运结构及货源结构4个子模块。模型结构与行为等检验方式验证了该模型的有效性。最后基本模拟和政策模拟结果分析为港口集疏运发展决策提供理论依据和指导。  相似文献   

17.
Cargo ship designs offered by shipbuilders differ in characteristics such as deadweight, speed, fuel consumption and cargo equipment. The best vessel for high freight markets and high fuel prices may not be the best for low freight markets and low fuel prices. A model has been developed to compare by simulation a number of multi-purpose general cargo vessels suitable for the trade of a Turkish shipowner. The model simulates the operation of each vessel under a variety of operating scenarios, e.g. fuel prices and freight profiles over the ships' lives, and estimates the distribution of resulting net present values. The techno-economic simulation model incorporates variables including ship size, speed, first cost, fuel consumption, load factor and port days.

Results are presented for six standard vessels of around 20 000 dwt operating over a long and a short route. Although the ranking of the six varies with assumptions, one design is shown to be superior under most operating conditions.  相似文献   

18.
International containerized freight movement is a vital part of the supply chain for many companies, and a critical element of moving consumer goods to points of retail sale within the U.S. Containerized imports also present a clear security concern (e.g., terrorists attempting to ship “dirty bombs,” chemical, biological or even nuclear weapons, into the U.S. in a shipping container). The goal of the research presented here is to create a modeling tool for analyzing flows of U.S. imports and exports of containerized freight, and the potential changes in those flows under a variety of conditions (e.g., port disruptions, extensive security-related delays, etc.). Our focus is on movements through maritime container ports, and not overland movements between the U.S. and Canada or Mexico.The network model, referred to as the System for Import/Export Routing and Recovery Analysis (SIERRA), represents container movements between the U.S. and 46 other countries that account for the vast majority of U.S. imports and exports. The SIERRA model is a network equilibrium model that predicts flows between foreign countries and North American ports, the total volumes handled (import and export) by each port, the modal volumes (truck and rail) moving domestically into and out of each port, and volumes between each port and a set of transportation analysis zones within the U.S.  相似文献   

19.
The Belgian government intends to shift part of its funding away from Antwerp and towards other seaports, particularly Ghent and Zeebrugge. In the long run, this policy change will undoubtedly influence the port choice and probably cause a traffic diversion at the expense of Antwerp. This will have a great influence on the structure of inland transportation.

The impact of port choice on inland transportation is the central theme of this paper. To this end a disaggregated model of the demand for freight transport is constructed.  相似文献   

20.
Literature has focused on studying port choice independently or as an element of a supply chain without considering the joint selection with the country of origin/destination of the imports/exports. However, the characteristics and location of a port may make it more attractive to mobilise more freight from/to some particular countries rather than others, making the port choice decision dependent on the country of origin/destination of the cargo. This article proposes advanced econometric models to evaluate simultaneously port choice and the country of origin/destination choice for Colombian imports and exports. Findings suggest that for imports and exports domestic freight rate is the most important variable for the joint choice process. Also, for exports, maritime transit time is more relevant than for imports, while for the frequency of shipping lines the opposite is true. The existence of a trade agreement and the gross domestic product per capita also have a significant influence on the election of a country for exports/imports.  相似文献   

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