1国际单位制(SI)、SI词头及其中文名称的简要历史1.1国际单位制及我国法定计量单位1875年,法国、英国、美国等17个国家签署了《米制公约》,确定米制作为国际通用的测量单位制。《米制公约》的签署对计量发展产生了深远影响,国际单位制...1国际单位制(SI)、SI词头及其中文名称的简要历史1.1国际单位制及我国法定计量单位1875年,法国、英国、美国等17个国家签署了《米制公约》,确定米制作为国际通用的测量单位制。《米制公约》的签署对计量发展产生了深远影响,国际单位制正是在米制的基础上逐渐发展并建立起来的。1954年,第10届国际计量大会(General Conference of Weights&Measures,CGPM)在米制的基础上决定采用长度单位米、质量单位千克、时间单位秒、电流单位安培、热力学温度单位开尔文和发光强度单位坎德拉作为国际实用单位制的基本单位。展开更多
State-space equations were applied to formulate the queuing and delay of traffic at a single intersection in this paper. The signal control of a single intersection was then modeled as a discrete-time optimal control ...State-space equations were applied to formulate the queuing and delay of traffic at a single intersection in this paper. The signal control of a single intersection was then modeled as a discrete-time optimal control problem, with consideration of the constraints of stream conflicts, saturation flow rate, minimum green time, and maximum green time. The problem cannot be solved directly due to the nonlinear constraints. However, the results of qualitative analysis were used to develop a first-phase signal control algorithm. Simulation results show that the algorithm substantially reduces the total delay compared to fixed-time control.展开更多
文摘1国际单位制(SI)、SI词头及其中文名称的简要历史1.1国际单位制及我国法定计量单位1875年,法国、英国、美国等17个国家签署了《米制公约》,确定米制作为国际通用的测量单位制。《米制公约》的签署对计量发展产生了深远影响,国际单位制正是在米制的基础上逐渐发展并建立起来的。1954年,第10届国际计量大会(General Conference of Weights&Measures,CGPM)在米制的基础上决定采用长度单位米、质量单位千克、时间单位秒、电流单位安培、热力学温度单位开尔文和发光强度单位坎德拉作为国际实用单位制的基本单位。
基金Supported by the National Natural Science Foundation of China (No. 60572005)
文摘State-space equations were applied to formulate the queuing and delay of traffic at a single intersection in this paper. The signal control of a single intersection was then modeled as a discrete-time optimal control problem, with consideration of the constraints of stream conflicts, saturation flow rate, minimum green time, and maximum green time. The problem cannot be solved directly due to the nonlinear constraints. However, the results of qualitative analysis were used to develop a first-phase signal control algorithm. Simulation results show that the algorithm substantially reduces the total delay compared to fixed-time control.
