为了提高支持向量回归(SVR,support vector regression)进行数据驱动预测的精度,针对SVR存在的参数优化问题,通过引入Tent混沌映射进行种群初始化、改进收敛方式、并结合模拟退火算法,改进了传统的灰狼优化算法(GWO,grey wolf optimizat...为了提高支持向量回归(SVR,support vector regression)进行数据驱动预测的精度,针对SVR存在的参数优化问题,通过引入Tent混沌映射进行种群初始化、改进收敛方式、并结合模拟退火算法,改进了传统的灰狼优化算法(GWO,grey wolf optimization)来优化SVR超参数,并基于改进后的GWO算法提出了一种IGWO-SVR预测模型;将提出的IGWO-SVR模型应用于NASA锂电池数据集仿真SOH预测以及实际生产中的车灯电流预测实验后,实验结果表明IGWO-SVR预测模型在NASA锂电池数据集上进行预测的误差相较GWO-SVR模型降低了23%,相较粒子群算法和遗传算法优化的SVR模型均存在明显优势,误差分别降低了39%和51%;在实际工作中使用IGWO-SVR模型进行车灯电流预测也取得良好效果,与实测值之间的相对误差达到2.67%,相较GWO-SVR模型误差降低了近7个百分点,证明了模型在实际应用中具有良好的价值。展开更多
Flight delay prediction remains an important research topic due to dynamic nature in flight operation and numerous delay factors.Dynamic data-driven application system in the control area can provide a solution to thi...Flight delay prediction remains an important research topic due to dynamic nature in flight operation and numerous delay factors.Dynamic data-driven application system in the control area can provide a solution to this problem.However,in order to apply the approach,a state-space flight delay model needs to be established to represent the relationship among system states,as well as the relationship between system states and input/output variables.Based on the analysis of delay event sequence in a single flight,a state-space mixture model is established and input variables in the model are studied.Case study is also carried out on historical flight delay data.In addition,the genetic expectation-maximization（EM）algorithm is used to obtain the global optimal estimates of parameters in the mixture model,and results fit the historical data.At last,the model is validated in Kolmogorov-Smirnov tests.Results show that the model has reasonable goodness of fitting the data,and the search performance of traditional EM algorithm can be improved by using the genetic algorithm.展开更多
Traffic flow prediction is an important component for real-time traffic-adaptive signal control in urban arterial networks.By exploring available detector and signal controller information from neighboring intersectio...Traffic flow prediction is an important component for real-time traffic-adaptive signal control in urban arterial networks.By exploring available detector and signal controller information from neighboring intersections,a dynamic data-driven flow prediction model was developed.The model consists of two prediction components based on the signal states(red or green) for each movement at an upstream intersection.The characteristics of each signal state were carefully examined and the corresponding travel time from the upstream intersection to the approach in question at the downstream intersection was predicted.With an online turning proportion estimation method,along with the predicted travel times,the anticipated vehicle arrivals can be forecasted at the downstream intersection.The model performance was tested at a set of two signalized intersections located in the city of Gainesville,Florida,USA,using the CORSIM microscopic simulation package.Analysis results show that the model agrees well with empirical arrival data measured at 10 s intervals within an acceptable range of 10%-20%,and show a normal distribution.It is reasonably believed that the model has potential applicability for use in truly proactive real-time traffic adaptive signal control systems.展开更多
文摘为了提高支持向量回归(SVR,support vector regression)进行数据驱动预测的精度,针对SVR存在的参数优化问题,通过引入Tent混沌映射进行种群初始化、改进收敛方式、并结合模拟退火算法,改进了传统的灰狼优化算法(GWO,grey wolf optimization)来优化SVR超参数,并基于改进后的GWO算法提出了一种IGWO-SVR预测模型;将提出的IGWO-SVR模型应用于NASA锂电池数据集仿真SOH预测以及实际生产中的车灯电流预测实验后,实验结果表明IGWO-SVR预测模型在NASA锂电池数据集上进行预测的误差相较GWO-SVR模型降低了23%,相较粒子群算法和遗传算法优化的SVR模型均存在明显优势,误差分别降低了39%和51%;在实际工作中使用IGWO-SVR模型进行车灯电流预测也取得良好效果,与实测值之间的相对误差达到2.67%,相较GWO-SVR模型误差降低了近7个百分点,证明了模型在实际应用中具有良好的价值。
基金Supported by the High Technology Research and Development Programme of China(2006AA12A106)~~
文摘Flight delay prediction remains an important research topic due to dynamic nature in flight operation and numerous delay factors.Dynamic data-driven application system in the control area can provide a solution to this problem.However,in order to apply the approach,a state-space flight delay model needs to be established to represent the relationship among system states,as well as the relationship between system states and input/output variables.Based on the analysis of delay event sequence in a single flight,a state-space mixture model is established and input variables in the model are studied.Case study is also carried out on historical flight delay data.In addition,the genetic expectation-maximization（EM）algorithm is used to obtain the global optimal estimates of parameters in the mixture model,and results fit the historical data.At last,the model is validated in Kolmogorov-Smirnov tests.Results show that the model has reasonable goodness of fitting the data,and the search performance of traditional EM algorithm can be improved by using the genetic algorithm.
基金Project(71101109) supported by the National Natural Science Foundation of China
文摘Traffic flow prediction is an important component for real-time traffic-adaptive signal control in urban arterial networks.By exploring available detector and signal controller information from neighboring intersections,a dynamic data-driven flow prediction model was developed.The model consists of two prediction components based on the signal states(red or green) for each movement at an upstream intersection.The characteristics of each signal state were carefully examined and the corresponding travel time from the upstream intersection to the approach in question at the downstream intersection was predicted.With an online turning proportion estimation method,along with the predicted travel times,the anticipated vehicle arrivals can be forecasted at the downstream intersection.The model performance was tested at a set of two signalized intersections located in the city of Gainesville,Florida,USA,using the CORSIM microscopic simulation package.Analysis results show that the model agrees well with empirical arrival data measured at 10 s intervals within an acceptable range of 10%-20%,and show a normal distribution.It is reasonably believed that the model has potential applicability for use in truly proactive real-time traffic adaptive signal control systems.
