基于无偏灰色Verhulst模型的铁路货运量预测研究
Railway freight volume forecasting based onunbiased grey Verhulst model

铁路工程项目投资和效益的控制，铁路运输发展战略的制定以及铁路运输设施效益的提高都与铁路货运量密切相关，准确预测铁路货运量具有重要意义。根据无偏GM(1,1)模型直接建模法的思想对传统灰色Verhulst进行改进，即对原始序列作倒数生成，运用新生成的序列建立模型，便可得到无偏灰色Verhulst模型。改进后的模型消除了灰色Verhulst模型自身固有的偏差，用此模型预测兰州至中川铁路货运量，结果表明，无偏灰色Verhulst模型比传统灰色Verhulst模型和GM(1,1)模型的预测精度更高。
Controls of investment and benefits in railway engineering project, formulation of development strategy of railway transportation and efficiency of railway transport facilities are the four parts that are closely related to the railway freight volume. It is of great significance to predict railway freight volume accurately. According to the idea of direct modeling method of unbiased GM(1,1) model, a traditional grey Verhulst is improved ,that is reciprocal sequence of original is generated and unbiased grey Verhulst model is built by the newly generated one. This model can eliminates the inherent bias and can be used to forecast freight volume from Lanzhou to zhongchuan. The results show that, compared with traditional grey Verhulst model and GM(1,1) model, predictions of unbiased grey Verhulst model are more accurate