Spare parts are very essential in most industrial companies. They are characterized by their large number and their high impact on the companies’ operations whenever needed. Therefore companies tend to analyze their ...Spare parts are very essential in most industrial companies. They are characterized by their large number and their high impact on the companies’ operations whenever needed. Therefore companies tend to analyze their spare parts demand and try to estimate their future consumption. Nevertheless, they face difficulties in figuring out an optimal forecasting method that deals with the lumpy and intermittent demand of spare parts. In this paper, we performed a comparison between five forecasting methods based on three statistical tools;Mean squared error (MSE), mean absolute deviation (MAD) and mean error (ME), where the results showed close performance for all the methods associated with their optimal parameters and the frequency of the spare part demand. Therefore, we proposed to compare all the methods based on the tracking signal with the objective of minimizing the average number of out of controls. This approach was tested in a comparative study at a local paper mill company. Our findings showed that the application of the tracking signal approach helps companies to better select the optimal forecasting method and reduce forecast errors.展开更多
介绍正交信号修正法的基本思想并详细推导该算法的实现步骤,将一种改进后的正交信号修正法(orthogonal signal correction,OSC)与偏最小二乘法(partial least square method,PLS)相结合,对原始数据通过OSC消除正交分量,利用PLS建立中长...介绍正交信号修正法的基本思想并详细推导该算法的实现步骤,将一种改进后的正交信号修正法(orthogonal signal correction,OSC)与偏最小二乘法(partial least square method,PLS)相结合,对原始数据通过OSC消除正交分量,利用PLS建立中长期负荷预测模型。该方法能有效地去除自变量系统中与因变量无关的正交数据信息,增强自变量、因变量之间的相关性,在有限的成分中提高成分解释能力。通过算例将PLS与OSC-PLS进行比较分析,结果表明,运用OSC-PLS进行中长期负荷预测,尽管预测模型提取的成分个数变少了,但模型成分的解释性却大幅度增强,预测精度明显提高,具有较强的实用性。展开更多
The primary physical factors,such as plateau meteorological factor,westerlies system,subtropical high and so on,which impact on summer precipitation over the southwest region of China,are analyzed.Then based on the re...The primary physical factors,such as plateau meteorological factor,westerlies system,subtropical high and so on,which impact on summer precipitation over the southwest region of China,are analyzed.Then based on the relationship between the physical factors and predictand,the predictive models of precipitation in Sichuan basin are developed.The forecast accuracy of operational experiments in recent years is improved.展开更多
文摘Spare parts are very essential in most industrial companies. They are characterized by their large number and their high impact on the companies’ operations whenever needed. Therefore companies tend to analyze their spare parts demand and try to estimate their future consumption. Nevertheless, they face difficulties in figuring out an optimal forecasting method that deals with the lumpy and intermittent demand of spare parts. In this paper, we performed a comparison between five forecasting methods based on three statistical tools;Mean squared error (MSE), mean absolute deviation (MAD) and mean error (ME), where the results showed close performance for all the methods associated with their optimal parameters and the frequency of the spare part demand. Therefore, we proposed to compare all the methods based on the tracking signal with the objective of minimizing the average number of out of controls. This approach was tested in a comparative study at a local paper mill company. Our findings showed that the application of the tracking signal approach helps companies to better select the optimal forecasting method and reduce forecast errors.
文摘介绍正交信号修正法的基本思想并详细推导该算法的实现步骤,将一种改进后的正交信号修正法(orthogonal signal correction,OSC)与偏最小二乘法(partial least square method,PLS)相结合,对原始数据通过OSC消除正交分量,利用PLS建立中长期负荷预测模型。该方法能有效地去除自变量系统中与因变量无关的正交数据信息,增强自变量、因变量之间的相关性,在有限的成分中提高成分解释能力。通过算例将PLS与OSC-PLS进行比较分析,结果表明,运用OSC-PLS进行中长期负荷预测,尽管预测模型提取的成分个数变少了,但模型成分的解释性却大幅度增强,预测精度明显提高,具有较强的实用性。
文摘The primary physical factors,such as plateau meteorological factor,westerlies system,subtropical high and so on,which impact on summer precipitation over the southwest region of China,are analyzed.Then based on the relationship between the physical factors and predictand,the predictive models of precipitation in Sichuan basin are developed.The forecast accuracy of operational experiments in recent years is improved.
