Because of the difficulty to obtain the traffic flow information of lanes at non-detector intersections in most metropolises of the world,based on the relationships between the lanes of signal-controlled intersections...Because of the difficulty to obtain the traffic flow information of lanes at non-detector intersections in most metropolises of the world,based on the relationships between the lanes of signal-controlled intersections,cluster analysis and stepwise regression are integrated to predict the traffic volume of lanes at non-detector isolated controlled intersections.First cluster analysis is used to cluster the lanes of non-detector isolated signal-controlled intersections and the lanes of all signal-controlled intersections with detectors.Then, by the results of cluster analysis,the traffic volume samples are selected randomly and stepwise regression is used to predict the traffic volume of lanes at non-detector isolated signal-controlled intersections.The method is tested by the traffic volume data of lanes of the road network of Nanjing city.The problem of predicting the traffic volume of lanes at non-detector isolated signal-controlled intersections was resolved and can be widely used in urban traffic flow guidance and urban traffic control in cities without enough intersections equipped with detectors.展开更多
目前,道路机动车辆逐年增多,如此发展下去,直至可预见的将来,在德、荷、比等人口高密度的欧洲国家里,将导致城市道路无休止的堵塞,周围环境严重的污染和噪声等级的明显升高。为了摆脱上述困境,建议推行运输分类制度(Transport Class Sys...目前,道路机动车辆逐年增多,如此发展下去,直至可预见的将来,在德、荷、比等人口高密度的欧洲国家里,将导致城市道路无休止的堵塞,周围环境严重的污染和噪声等级的明显升高。为了摆脱上述困境,建议推行运输分类制度(Transport Class System),这一制度是通过可替换的标准车(货)厢,来实施运输车辆“结构”布局的革新。展开更多
Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research...Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research status of the combined cycle engine technology,including basic principle,research programs and classification of structure is firstly discussed in this paper.Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design.Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms,in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles.展开更多
基金The National Natural Science Foundation of China(No.50378016).
文摘Because of the difficulty to obtain the traffic flow information of lanes at non-detector intersections in most metropolises of the world,based on the relationships between the lanes of signal-controlled intersections,cluster analysis and stepwise regression are integrated to predict the traffic volume of lanes at non-detector isolated controlled intersections.First cluster analysis is used to cluster the lanes of non-detector isolated signal-controlled intersections and the lanes of all signal-controlled intersections with detectors.Then, by the results of cluster analysis,the traffic volume samples are selected randomly and stepwise regression is used to predict the traffic volume of lanes at non-detector isolated signal-controlled intersections.The method is tested by the traffic volume data of lanes of the road network of Nanjing city.The problem of predicting the traffic volume of lanes at non-detector isolated signal-controlled intersections was resolved and can be widely used in urban traffic flow guidance and urban traffic control in cities without enough intersections equipped with detectors.
文摘目前,道路机动车辆逐年增多,如此发展下去,直至可预见的将来,在德、荷、比等人口高密度的欧洲国家里,将导致城市道路无休止的堵塞,周围环境严重的污染和噪声等级的明显升高。为了摆脱上述困境,建议推行运输分类制度(Transport Class System),这一制度是通过可替换的标准车(货)厢,来实施运输车辆“结构”布局的革新。
文摘Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research status of the combined cycle engine technology,including basic principle,research programs and classification of structure is firstly discussed in this paper.Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design.Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms,in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles.
