采用GNSS数据中心提供GPS/BDS钟差数据作为实验数据,对二次多项式模型(the Quadratic PolynoMial(QP)model)、灰色模型(the Gray system Model(GM(1,1)))、时间序列模型(the ARIMA time series model)、卡尔曼滤波模型(KF)、小波神经网...采用GNSS数据中心提供GPS/BDS钟差数据作为实验数据,对二次多项式模型(the Quadratic PolynoMial(QP)model)、灰色模型(the Gray system Model(GM(1,1)))、时间序列模型(the ARIMA time series model)、卡尔曼滤波模型(KF)、小波神经网络模型(Wavelet Neural Network(WNN))五种模型钟差短期预报的效果进行分析和比较,总结了各模型预报钟差的优点与不足。展开更多
[Objective] Taken the Linjiang tourism as an example, tourism forecast system was established, difficulties related to the work of tourist area were solved. [Method] Dynamic predicted response model of Lijiang tourism...[Objective] Taken the Linjiang tourism as an example, tourism forecast system was established, difficulties related to the work of tourist area were solved. [Method] Dynamic predicted response model of Lijiang tourism market was established, through the gray correlation model GM (1, 1) and time-series method, using a computer simulation program for the actual model of operation, Lijiang tourism prospects were predicted and predicting results were evaluated. [Result] Total revenue of model gray parameter of Lijiang tourism a= 0.572 3 from 2009 to 2011, internal control parameters u=0.393 7, x(t+1) =-0.563 3exp(-0.572 3t)+0.688 0; total reception numbers of model gray parameter of Lijiang tourism a = 0.125 6, internal control parameters u = 344. 326 0, x(t+1)=3 102.483 5 exp(0.125 6 t)-2 741.283 5. Test results of two models showed that fitting degrees were good, and at the same time predicted that total revenue of Lijiang tourism reached 13 000 000 000, and total reception numbers reached 8 800 000. [Conclusion] This predicted system can carry out precision forecast for other tourist areas when cannot get all the information.展开更多
Grey system theory has been widely applied to many domains such as economy, agriculture, management, Social Sciences and so on. Based on the theory of grey system, this paper established GM（1,1） grey predict model f...Grey system theory has been widely applied to many domains such as economy, agriculture, management, Social Sciences and so on. Based on the theory of grey system, this paper established GM（1,1） grey predict model for the first time to forecast The number of Scitech novelty search item and The staff number of Sci-Tech Novelty Search. The predicting results are almost close to the actual values, which shows that the model is reliable so that the models could be used to forecast the two factors in the future years. The study will help the scientific management of Sci-Tech Novelty search work for Novelty search organizations.展开更多
Based on the situation that the statistic of the missile facilities＇ stability was small, and the conventional big example preview method was no longer of use. So, this article used the gray GM （1, 1） model to prev...Based on the situation that the statistic of the missile facilities＇ stability was small, and the conventional big example preview method was no longer of use. So, this article used the gray GM （1, 1） model to preview a facility＇ s stability .The gray GM （1, 1） model doesn＇ t need a large number of example statistics, and it is also accurate, so this model solved the problem in the analyze and preview of the stability of the missile＇ s electronic facility system, and it has possibility to imply to engineering use.展开更多
Ship motion,with six degrees of freedom,is a complex stochastic process.Sea wind and waves are the primary influencing factors.Prediction of ship motion is significant for ship navigation.To eliminate errors,a path pr...Ship motion,with six degrees of freedom,is a complex stochastic process.Sea wind and waves are the primary influencing factors.Prediction of ship motion is significant for ship navigation.To eliminate errors,a path prediction model incorporating ship pitching was developed using the Gray topological method,after analyzing ship pitching motions.With the help of simple introduction to Gray system theory,we selected a group of threshold values.Based on an analysis of ship pitch angle sequences over 40 second intervals,a Grey metabolism GM(1,1) model was established according to the time-series which every threshold corresponded to.Forecasting future ship motion with the GM(1,1) model allowed drawing of the forecast curve with effective forecasting points.The precision of the test results show that the model is accurate,and the forecast results are reliable.展开更多
The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived usi...The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived using the optimally weighted combination theory and the minimum sum of logarithmic squared errors as the objective function.Two typical anchor bolt pull-out engineering cases were selected to compare the performance of the proposed model with those of existing ones.Results showed that the optimal combination model was suitable not only for the slow P-s curve but also for the steep P-s curve.Its accuracy and stable reliability,as well as its prediction capability classification,were better than those of the other prediction models.Therefore,the optimal combination model is an effective processing method for predicting the maximum pull-out load of anchor bolts according to measured data.展开更多
文摘采用GNSS数据中心提供GPS/BDS钟差数据作为实验数据,对二次多项式模型(the Quadratic PolynoMial(QP)model)、灰色模型(the Gray system Model(GM(1,1)))、时间序列模型(the ARIMA time series model)、卡尔曼滤波模型(KF)、小波神经网络模型(Wavelet Neural Network(WNN))五种模型钟差短期预报的效果进行分析和比较,总结了各模型预报钟差的优点与不足。
基金Supported by National Social Science Foundation of China(08BMZ042)~~
文摘[Objective] Taken the Linjiang tourism as an example, tourism forecast system was established, difficulties related to the work of tourist area were solved. [Method] Dynamic predicted response model of Lijiang tourism market was established, through the gray correlation model GM (1, 1) and time-series method, using a computer simulation program for the actual model of operation, Lijiang tourism prospects were predicted and predicting results were evaluated. [Result] Total revenue of model gray parameter of Lijiang tourism a= 0.572 3 from 2009 to 2011, internal control parameters u=0.393 7, x(t+1) =-0.563 3exp(-0.572 3t)+0.688 0; total reception numbers of model gray parameter of Lijiang tourism a = 0.125 6, internal control parameters u = 344. 326 0, x(t+1)=3 102.483 5 exp(0.125 6 t)-2 741.283 5. Test results of two models showed that fitting degrees were good, and at the same time predicted that total revenue of Lijiang tourism reached 13 000 000 000, and total reception numbers reached 8 800 000. [Conclusion] This predicted system can carry out precision forecast for other tourist areas when cannot get all the information.
文摘Grey system theory has been widely applied to many domains such as economy, agriculture, management, Social Sciences and so on. Based on the theory of grey system, this paper established GM（1,1） grey predict model for the first time to forecast The number of Scitech novelty search item and The staff number of Sci-Tech Novelty Search. The predicting results are almost close to the actual values, which shows that the model is reliable so that the models could be used to forecast the two factors in the future years. The study will help the scientific management of Sci-Tech Novelty search work for Novelty search organizations.
文摘Based on the situation that the statistic of the missile facilities＇ stability was small, and the conventional big example preview method was no longer of use. So, this article used the gray GM （1, 1） model to preview a facility＇ s stability .The gray GM （1, 1） model doesn＇ t need a large number of example statistics, and it is also accurate, so this model solved the problem in the analyze and preview of the stability of the missile＇ s electronic facility system, and it has possibility to imply to engineering use.
文摘Ship motion,with six degrees of freedom,is a complex stochastic process.Sea wind and waves are the primary influencing factors.Prediction of ship motion is significant for ship navigation.To eliminate errors,a path prediction model incorporating ship pitching was developed using the Gray topological method,after analyzing ship pitching motions.With the help of simple introduction to Gray system theory,we selected a group of threshold values.Based on an analysis of ship pitch angle sequences over 40 second intervals,a Grey metabolism GM(1,1) model was established according to the time-series which every threshold corresponded to.Forecasting future ship motion with the GM(1,1) model allowed drawing of the forecast curve with effective forecasting points.The precision of the test results show that the model is accurate,and the forecast results are reliable.
基金The National Natural Science Foundation of China(No.51778485).
文摘The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived using the optimally weighted combination theory and the minimum sum of logarithmic squared errors as the objective function.Two typical anchor bolt pull-out engineering cases were selected to compare the performance of the proposed model with those of existing ones.Results showed that the optimal combination model was suitable not only for the slow P-s curve but also for the steep P-s curve.Its accuracy and stable reliability,as well as its prediction capability classification,were better than those of the other prediction models.Therefore,the optimal combination model is an effective processing method for predicting the maximum pull-out load of anchor bolts according to measured data.
