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ARMA模型在预测船价指数中的应用 总被引:1,自引:0,他引:1
船价是造船行业中最重要的指标之一,目前市场预测船价指数方法均没有考虑船价的自身长期趋势,为此在预测船价指数中引入ARMA模型,充分考虑了时间序列自身的发展趋势,以得出更准确的船价预期. 相似文献
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利用多种方法对复航河流沿岸港区吞吐量发展水平作出预测。近期预测主要采用时间序列法、灰色模型法和修正指数曲线法,对各方法预测结果加权平均得出吞吐量预测值。远期预测时,利用灰色模型曲线和修正指数曲线构造复合曲线获得吞吐量预测值。最后在定性分析的基础上对吞吐量预测值作出修正。 相似文献
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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。文中根据苏州港集装箱吞吐量、货物吞吐量的历史数据,建立了时间序列的三次指数平滑模型预测模型,对苏州港集装箱吞吐量、货物吞吐量加以预测和分析,并提出了苏州港进一步发展的策略。 相似文献
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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
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港口集装箱吞吐量的合理预测对提高港口竞争力与经济效益具有决定意义。为了提高港口集装箱吞吐量预测精度,分别采用时间序列法中的三次指数平滑法、灰色GM(1,1)法和因果分析法中的多元回归分析法对集装箱吞吐量进行预测。在此基础上运用多元回归法进行吞吐量预测模型的组合分析,根据预测结果与实际吞吐量进行优化组合研究并建立预测综合模型。综合模型融合了前三种方法的优点,克服了单一预测方法的不确定性,改善预测效果,更加适合于南京港集装箱吞吐量的实际预测。 相似文献
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近年来国内外学者对波罗的海干散货运价指数(BDI)的预测建模做了许多分析和研究工作,笔者在认真研读相关文献的基础上,通过实证分析发现BDI指数收益率序列存在长记忆性,因此本文尝试引入ARFIMA模型来改进传统的ARMA预测模型。 相似文献
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目前我国部分地区货运量统计数据存在收集不全、统计口径不一致及社会经济环境变化大等问题,导致常规的时间序列预测法和回归预测法难以在这些地区应用。鉴于此,分析了国内外货运强度变化的规律,指出人均GDP和第三产业所占比例是影响货运强度的主要因子,提出了通过模糊聚类方法对地区货运发展阶段进行定位,找出其发展阶段所对应的货运强度值,进而提出依据人均GDP和第三产业所占比例进行货运量预测的方法。最后对邢台市的货运量预测进行了实证研究。 相似文献
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进口原油运输船型经济性分析 总被引:8,自引:0,他引:8
石油是世界海上运量最大的货种之一,约占海上总运输量的三分之一。加入WTO后,中国石油海上运输量,特别是进口原油运输量将大幅度地增加。针对这一现实情况,本文对世界原油运输船队的技术经济作了概括性分析,对原油进口航线作了介绍。建立了单船运输经济性测算模型。基于实船经济指标测算结果,以必要运费率为主,通过比较选出了优良船型。并定量测算出不同类型船舶在同一航线上营运的必要运费率及其差异。研究结果指出,随着进口原油量的大幅度增加,中国应大力发展VLCC和Suezmax船队,重点建设大型深水油轮码头。 相似文献
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内河航运是综合交通运输系统中不可缺少的运输方式,存在着很大的潜在优势.定量地把握未来内河运输的发展趋势,具有重大的现实意义.通过利用时间序列模型、logistic曲线与自回归模型等,对2010-2015年的上海内河货运量进行预测.在此基础上,对不同模型赋予不同的权重,建立了组合预测模型.研究表明:未来上海内河货运量将持续稳定地增长.为提高预测的精度,有必要综合地使用多个预测方法. 相似文献
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Jan A. Berg-Andereassen 《Maritime Policy and Management》1996,23(4):381-395
This paper tests two fundamental hypotheses concerning international maritime statistics. The first one deals with the question of stationary of the maritime market statistics. The second hypothesis tested is the assumption that the international maritime statistical time series are not distributed according to a normal of Guassian probability law, but rather belong to the same family of distributions with distinctly different critical parameters. Through well documented statistical methods, the paper concludes that the international freight rates observed on a day to day basis are generated by a random walk process. The paper finds that the shipping industry's conventioal wisdom is essentially correct. 'Last done' is as good a forecast of tomorrow's freight rate as any other generated by more sophisticated forecasting methods. Furthermore, freight rates and secondhand tonnage prices fluctuate closely together. The freight rates are generated by stochastic processes fully described by the Paretian family of distributions. The critical parameters of these distribution, the characteristic exponents, are such that the risk conscious ship operator can indeed reduce his exposure to risk by securing a correct set of freight rate contracts. 相似文献
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Jan A. Berg-Andereassen 《Maritime Policy and Management》2013,40(4):381-395
This paper tests two fundamental hypotheses concerning international maritime statistics. The first one deals with the question of stationary of the maritime market statistics. The second hypothesis tested is the assumption that the international maritime statistical time series are not distributed according to a normal of Guassian probability law, but rather belong to the same family of distributions with distinctly different critical parameters. Through well documented statistical methods, the paper concludes that the international freight rates observed on a day to day basis are generated by a random walk process. The paper finds that the shipping industry's conventioal wisdom is essentially correct. ‘Last done’ is as good a forecast of tomorrow's freight rate as any other generated by more sophisticated forecasting methods. Furthermore, freight rates and secondhand tonnage prices fluctuate closely together. The freight rates are generated by stochastic processes fully described by the Paretian family of distributions. The critical parameters of these distribution, the characteristic exponents, are such that the risk conscious ship operator can indeed reduce his exposure to risk by securing a correct set of freight rate contracts. 相似文献
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General economists, as well as Maritime economists, assume that the time series they forecast follow normal distribution, and data is independently and identically distributed around the mean. This paper contests this assumption with the aid of three sets of time series: (1) The Dry Cargo Freight Index, 1741–2005: in this series the data deviate from the mean by more than three standard deviations on no fewer than six occasions, and exhibited “fat tails”; (2) The time charter freight rates for a 10-year-old, 80?000 dwt vessel from 6 January 1989 to 26 December 2008: this series also exhibits skewness and kurtosis in a leptokurtic distribution; and (3) The Dry Cargo Time Charter Index from 1971 to 2004: this series diverged from the normal distribution four times. Next, we searched more recent data for short-term cycles using the V-statistic. One cycle was found to last 4 years (2005 to 2008), which is in accordance with theory. This cycle started on 29 July 2005 and ended when it reached the (lowest) level of $4000 on 1 December 2008. A new 4-year cycle started on 1 December 2008 and is forecast to last until the end of 2010. Short-term forecasting of the cycle using V-statistic is theoretically confirmed by the theory advanced by Hampton [1990, published in 1989, ‘Analysis and shipping cycles I and II’, Seatrade Journal, 19–23. Long and Short Shipping Cycles: The Rhythms and Psychology of Shipping Markets, Monograph, 2nd ed. (Cambridge: Cambridge Academy of Transport), March, p. 66]. 相似文献
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Peter Nielsen Liping Jiang Niels Gorm Malý Rytter Gang Chen 《Maritime Policy and Management》2014,41(7):667-682
This paper evaluates the influence of forecast horizon and observation fit on the robustness and performance of a specific freight rate forecast model used in the liner shipping industry. In the first stage of the research, a forecast model used to predict container freight rate development is presented by exploring the relationship between individual company’s rates and aggregated market rates, and thus assists in dealing with uncertainty and market volatility for a given business situation. In the second stage, a design of experiment approach is applied to highlight the influence of the forecast horizon and observation fit and their interactions on the forecast model’s performance. The results underline the complicated nature of creating a suitable forecast model by balancing business needs, a desire to fit a good model and achieve high accuracy. There is strong empirical evidence from this study; that a robust model is preferable, that overfitting is a true danger, and that a balance must be achieved between forecast horizon and the number of observations used to fit the model. In addition, methodological guidance has also been provided on how to test, design, and choose the superior model for business needs. 相似文献
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Jostein Tvedt 《Maritime Policy and Management》2003,30(3):221-230
The main result of this article is that freight rates and second hand prices in the dry bulk market seem to be stationary. By unit-root tests, an established tool for testing for random walk in economic time series, the random walk hypothesis can be rejected in most cases for the freight rate samples. This result is in contrast to the findings of a number of papers during the 1990s. However, the results confirm classical shipping market models that indicate stationarity in freight rates, which is not the case if the freight rates follow a random walk. By transforming all observations from US$ to Japanese yen detrended freight rates and prices seem to become stationary and volatility is reduced. 相似文献