In this study,the relationship between space mean speed(SMS),flow rate and density of pedestrians was investigated in different pedestrian facilities,including 1 walkway,2 sidewalks,2 signalized crosswalks and 2 mid-b...In this study,the relationship between space mean speed(SMS),flow rate and density of pedestrians was investigated in different pedestrian facilities,including 1 walkway,2 sidewalks,2 signalized crosswalks and 2 mid-block crosswalks.First,statistical analysis was performed to investigate the normality of data and correlation of variables.Regression analysis was then applied to determine the relationship between SMS,flow rate,and density of pedestrians.Finally,two prediction models of density were obtained using genetic programming(GP)and group method of data handling(GMDH)models,and k-fold and holdout cross-validation methods were used to evaluate the models.By the use of regression analysis,the mathematical relationships between variables in all facilities were calculated and plotted,and the best relationships were observed in flow rate-density diagrams.Results also indicated that GP had a higher R2 than GMDH in the prediction of pedestrian density in terms of flow rate and SMS,suggesting that GP was better able to model SMS and pedestrian density.Moreover,the application of k-fold cross-validation method in the models led to better performances compared to the holdout cross-validation method,which shows that the prediction models using k-fold were more reliable.Finally,density relationships in all facilities were obtained in terms of SMS and flow rate.展开更多
This study was originally aimed at suggesting a two-dimensional program for the Steam Assisted Gravity Drainage(SAGD)process based on the correlations proposed by Heidari and Pooladi,using the MATLAB software.In fact,...This study was originally aimed at suggesting a two-dimensional program for the Steam Assisted Gravity Drainage(SAGD)process based on the correlations proposed by Heidari and Pooladi,using the MATLAB software.In fact,the work presented by Chung and Butler was used as the basis for this study.Since the steam chamber development process and the SAGD production performance are functions of reservoir properties and operational parameters,the new model is capable of analyzing the effects of parameters such as height variation at constant length,length variation at constant height,permeability variation,thermal diffusivity coefficient variation and well location on the production rate and the oil recovery among which,the most important one is the thermal diffusivity coefficient analysis.To investigate the accuracy and authenticity of the model outcomes,they were compared with the results obtained by Chung and Butler.The privilege of this method over that proposed by Heidari and Pooladi lies in its ability to investigate the effect of thermal diffusivity coefficient on recovery and analyzing the effect of temperature distribution changes on thickness diffusivity.Based on the observations,results reveal that the proposed model gives more accurate predictions compared to the old model proposed by Chung&Butler.展开更多
文摘In this study,the relationship between space mean speed(SMS),flow rate and density of pedestrians was investigated in different pedestrian facilities,including 1 walkway,2 sidewalks,2 signalized crosswalks and 2 mid-block crosswalks.First,statistical analysis was performed to investigate the normality of data and correlation of variables.Regression analysis was then applied to determine the relationship between SMS,flow rate,and density of pedestrians.Finally,two prediction models of density were obtained using genetic programming(GP)and group method of data handling(GMDH)models,and k-fold and holdout cross-validation methods were used to evaluate the models.By the use of regression analysis,the mathematical relationships between variables in all facilities were calculated and plotted,and the best relationships were observed in flow rate-density diagrams.Results also indicated that GP had a higher R2 than GMDH in the prediction of pedestrian density in terms of flow rate and SMS,suggesting that GP was better able to model SMS and pedestrian density.Moreover,the application of k-fold cross-validation method in the models led to better performances compared to the holdout cross-validation method,which shows that the prediction models using k-fold were more reliable.Finally,density relationships in all facilities were obtained in terms of SMS and flow rate.
文摘This study was originally aimed at suggesting a two-dimensional program for the Steam Assisted Gravity Drainage(SAGD)process based on the correlations proposed by Heidari and Pooladi,using the MATLAB software.In fact,the work presented by Chung and Butler was used as the basis for this study.Since the steam chamber development process and the SAGD production performance are functions of reservoir properties and operational parameters,the new model is capable of analyzing the effects of parameters such as height variation at constant length,length variation at constant height,permeability variation,thermal diffusivity coefficient variation and well location on the production rate and the oil recovery among which,the most important one is the thermal diffusivity coefficient analysis.To investigate the accuracy and authenticity of the model outcomes,they were compared with the results obtained by Chung and Butler.The privilege of this method over that proposed by Heidari and Pooladi lies in its ability to investigate the effect of thermal diffusivity coefficient on recovery and analyzing the effect of temperature distribution changes on thickness diffusivity.Based on the observations,results reveal that the proposed model gives more accurate predictions compared to the old model proposed by Chung&Butler.
