In this paper, according to the theory and method of time-series analysis, the grow ing rings ARIMA model of wood properties variation pattern for Larix olgensis plantation was studied. The model recognition and param...In this paper, according to the theory and method of time-series analysis, the grow ing rings ARIMA model of wood properties variation pattern for Larix olgensis plantation was studied. The model recognition and parameter estimation were discused. The ARIMA model of wood growth ring density, growth ring widith and late wood percentage was obtained. Appling the ARIMA model which obtained from actual test fitted the variation pattem of wood growth ring for Larix olgensis. The result indicated it was an effective method that applied the ARIMA model to study wood growth ring properties variation pattem. By comparing with the actual variation pattem from test data the goodness of fit was good.展开更多
根据城市道路短时交通流特征,在ARIMA(autoregressive integrated moving average model)模型和SARIMA(seasonal autoregressive integrated moving average model)模型的基础上,提出一种既满足城市道路日周期性和周周期性的短时交通流...根据城市道路短时交通流特征,在ARIMA(autoregressive integrated moving average model)模型和SARIMA(seasonal autoregressive integrated moving average model)模型的基础上,提出一种既满足城市道路日周期性和周周期性的短时交通流预测模型DSARIMA(double seasonal autoregressive integrated moving average model)模型,并根据城市道路工作日与非工作日交通流特点,提出该模型的预测算法。该算法采用两种方式利用ARIMA模型进行交通流预测,一种方式采用当前时刻前N1段时间进行预测,另一种方式采用当前时刻前N2天同一时段的交通流进行预测,并用改进的贝叶斯模型算法根据两种预测结果与实际值的误差来确定该种方式的权值,最后的预测结果为两种方式预测结果与其权值乘积之和。实验结果表明,该模型在交通流预测上,相比ARIMA模型和SARIMA模型预测具有更好的平稳性与更高的预测精度。展开更多
文摘In this paper, according to the theory and method of time-series analysis, the grow ing rings ARIMA model of wood properties variation pattern for Larix olgensis plantation was studied. The model recognition and parameter estimation were discused. The ARIMA model of wood growth ring density, growth ring widith and late wood percentage was obtained. Appling the ARIMA model which obtained from actual test fitted the variation pattem of wood growth ring for Larix olgensis. The result indicated it was an effective method that applied the ARIMA model to study wood growth ring properties variation pattem. By comparing with the actual variation pattem from test data the goodness of fit was good.
