Intelligent vehicles can effectively improve traffic congestion and road traffic safety.Adaptive cruise followingcontrol(ACFC)is a vital part of intelligent vehicles.In this paper,a new hierarchical vehicle-following ...Intelligent vehicles can effectively improve traffic congestion and road traffic safety.Adaptive cruise followingcontrol(ACFC)is a vital part of intelligent vehicles.In this paper,a new hierarchical vehicle-following control strategy is presented by synthesizing the variable time headway model,type-2 fuzzy control,feedforward+fuzzy proportion integration(PI)feedback(F+FPIF)control,and inverse longitudinal dynamics model of vehicles.Firstly,a traditional variable time headway model is improved considering the acceleration of the lead car.Secondly,an interval type-2 fuzzy logic controller(IT2 FLC)is designed for the upper structure of the ACFC system to simulate the driver's operating habits.To reduce the nonlinear influence and improve the tracking accuracy for the desired acceleration,the control strategy of F+FPIF is given for the lower control structure.Thirdly,the lower control method proposed in this paper is compared with the fuzzy PI control and the traditional method(no lower controller for tracking desired acceleration)separately.Meanwhile,the proportion integration differentiation(PID),linear quadratic regulator(LQR),subsection function control(SFC)and type-1 fuzzy logic control(T1 FLC)are respectively compared with the IT2 FLC in control performance under different scenes.Finally,the simulation results show the effectiveness of IT2 FLC for the upper structure and F+FPIF control for the lower structure.展开更多
The unmanned aerial vehicles( UAV) has been becoming more and more important in the aviation industry.Despite the superior performance and advanced technology,major accident of UAV happens frequently due to the impact...The unmanned aerial vehicles( UAV) has been becoming more and more important in the aviation industry.Despite the superior performance and advanced technology,major accident of UAV happens frequently due to the impact of their systems,long distance of remote control and skill of manipulator technology.According to the application of engineering application,failure mode effects and criticality analysis( FMECA),failure reporting analysis and corrective action comprehensive analysis systems( FRACAS)and fault tree analysis( FTA)( 3 F) were combined.And also a set of user-friendly,more time,more efficient and accurate reliability analysis system were explored.展开更多
Under the development situation of the new era, the state-owned enterprises should adjust their own development direction and comprehensively improve their comprehensive level. Financial management is a very basic and...Under the development situation of the new era, the state-owned enterprises should adjust their own development direction and comprehensively improve their comprehensive level. Financial management is a very basic and important link in enterprise management, which has a significant impact on the development of the whole enterprise. With the rapid development of our society and the gradual improvement of our economic level, many market enterprises are constantly reforming and developing in different directions. State-owned enterprises should also follow the trend of the times to reform and upgrade. Financial management reform is one of the important links. Among them, centralized accounting and integration of business and finance is the current focus of state-owned enterprises. This paper mainly focuses on the two, combining with the actual situation of the current state-owned enterprises, analyzes the existing problems and puts forward solutions, hoping to promote the improvement of the financial management level of the state-owned enterprises.展开更多
We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying （PDM-QPSK） signal transmission over fiber, wireless and fiber at Wband （75-110 GH...We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying （PDM-QPSK） signal transmission over fiber, wireless and fiber at Wband （75-110 GHz）. The generation of polarization multiplexing millimeter-wave （mm-wave） wireless signal is based on the photonic technique. After 20-km fiber transmission, polarization diversity and heterodyne beating are implemented to convert the polarization components of the polarization-multiplexing signals from the optical baseband to W-band so that up to 16 Gb/s mm-wave signals can be delivered over 2-m 2~2 multiple-input multiple-output （MIMO） wireless link. At the receiver base station （BS）, polarization combination reconstructs the PDM-QPSK signal which is then launched into another 20-km fiber. In the experiment, coherent detection is introduced to improve receiver sensitivity and constant modulus algorithm （CMA） is applied for polarization de-multiplexing. The bit-error-ratio （BER） for 16-Gb/s PDM- QPSK signal delivery is below the forward-error-correction （FEC） threshold of 3.8× 10-3 with the optical signal-to-noise ratio （OSNR） above 11.8 dB.展开更多
With the launch of the U.S.Green Building Council’s Leadership in Energy and Environmental Design(LEED^(■))rating system,new building construction in the United States has rapidly begun adopting this guide as the st...With the launch of the U.S.Green Building Council’s Leadership in Energy and Environmental Design(LEED^(■))rating system,new building construction in the United States has rapidly begun adopting this guide as the standard for sustainable building.The rating system profoundly alters the design and operation of buildings,however,to date,little has been documented on the cumulative effects of the rating system across different phases of the project lifecycle:planning,architecture/design,engineering,construction and operational facility management(AEC+P+F).Further,the ability to gain efficiencies in the building phase itself is still unknown.Implications of the delivery system in LEED^(■)attainment also have not been clearly associated with the level of AEC+P+F integration.To pursue this goal,project participants are becoming involved earlier in the process;information exchanges take place throughout the project lifecycle;and the results of those frequent exchanges impact the value to the owner through focus on attainment of a particular green rating score.These features are confi guring a framework for green project delivery.This framework approaches lean thinking by generating value to the owner,improving the flow of information,and transforming the inputs required for the selection of materials and systems,to outputs in the form of a sustainability rating certification.This research focuses on exploring associations between LEED^(■)criteria,project lifecycle,the stakeholders’interests,lean process improvements and typical delivery systems used in building construction.The paper proposes a matrix of weighted indexes to explain and provide increased collaboration among project participants,improved efficiency throughout the project lifecycle,and new techniques which may be incorporated into the construction process.展开更多
基金the National Natural Science Foundation of China(61473048,61074093,61873321)。
文摘Intelligent vehicles can effectively improve traffic congestion and road traffic safety.Adaptive cruise followingcontrol(ACFC)is a vital part of intelligent vehicles.In this paper,a new hierarchical vehicle-following control strategy is presented by synthesizing the variable time headway model,type-2 fuzzy control,feedforward+fuzzy proportion integration(PI)feedback(F+FPIF)control,and inverse longitudinal dynamics model of vehicles.Firstly,a traditional variable time headway model is improved considering the acceleration of the lead car.Secondly,an interval type-2 fuzzy logic controller(IT2 FLC)is designed for the upper structure of the ACFC system to simulate the driver's operating habits.To reduce the nonlinear influence and improve the tracking accuracy for the desired acceleration,the control strategy of F+FPIF is given for the lower control structure.Thirdly,the lower control method proposed in this paper is compared with the fuzzy PI control and the traditional method(no lower controller for tracking desired acceleration)separately.Meanwhile,the proportion integration differentiation(PID),linear quadratic regulator(LQR),subsection function control(SFC)and type-1 fuzzy logic control(T1 FLC)are respectively compared with the IT2 FLC in control performance under different scenes.Finally,the simulation results show the effectiveness of IT2 FLC for the upper structure and F+FPIF control for the lower structure.
基金Naional Natural Science Foundntion of China(No.71761030)
文摘The unmanned aerial vehicles( UAV) has been becoming more and more important in the aviation industry.Despite the superior performance and advanced technology,major accident of UAV happens frequently due to the impact of their systems,long distance of remote control and skill of manipulator technology.According to the application of engineering application,failure mode effects and criticality analysis( FMECA),failure reporting analysis and corrective action comprehensive analysis systems( FRACAS)and fault tree analysis( FTA)( 3 F) were combined.And also a set of user-friendly,more time,more efficient and accurate reliability analysis system were explored.
文摘Under the development situation of the new era, the state-owned enterprises should adjust their own development direction and comprehensively improve their comprehensive level. Financial management is a very basic and important link in enterprise management, which has a significant impact on the development of the whole enterprise. With the rapid development of our society and the gradual improvement of our economic level, many market enterprises are constantly reforming and developing in different directions. State-owned enterprises should also follow the trend of the times to reform and upgrade. Financial management reform is one of the important links. Among them, centralized accounting and integration of business and finance is the current focus of state-owned enterprises. This paper mainly focuses on the two, combining with the actual situation of the current state-owned enterprises, analyzes the existing problems and puts forward solutions, hoping to promote the improvement of the financial management level of the state-owned enterprises.
基金supported by the National Natural Science Foundation of China(Nos.61177071and 61250018)the National"863"Program of China(Nos.2011AA010302 and 2012AA011302)+1 种基金the National Key Technology R&D Program of China(No.2012BAH18B00)the International Cooperation Program of Shanghai Science and Technology Association(No.12510705600)
文摘We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying （PDM-QPSK） signal transmission over fiber, wireless and fiber at Wband （75-110 GHz）. The generation of polarization multiplexing millimeter-wave （mm-wave） wireless signal is based on the photonic technique. After 20-km fiber transmission, polarization diversity and heterodyne beating are implemented to convert the polarization components of the polarization-multiplexing signals from the optical baseband to W-band so that up to 16 Gb/s mm-wave signals can be delivered over 2-m 2~2 multiple-input multiple-output （MIMO） wireless link. At the receiver base station （BS）, polarization combination reconstructs the PDM-QPSK signal which is then launched into another 20-km fiber. In the experiment, coherent detection is introduced to improve receiver sensitivity and constant modulus algorithm （CMA） is applied for polarization de-multiplexing. The bit-error-ratio （BER） for 16-Gb/s PDM- QPSK signal delivery is below the forward-error-correction （FEC） threshold of 3.8× 10-3 with the optical signal-to-noise ratio （OSNR） above 11.8 dB.
文摘With the launch of the U.S.Green Building Council’s Leadership in Energy and Environmental Design(LEED^(■))rating system,new building construction in the United States has rapidly begun adopting this guide as the standard for sustainable building.The rating system profoundly alters the design and operation of buildings,however,to date,little has been documented on the cumulative effects of the rating system across different phases of the project lifecycle:planning,architecture/design,engineering,construction and operational facility management(AEC+P+F).Further,the ability to gain efficiencies in the building phase itself is still unknown.Implications of the delivery system in LEED^(■)attainment also have not been clearly associated with the level of AEC+P+F integration.To pursue this goal,project participants are becoming involved earlier in the process;information exchanges take place throughout the project lifecycle;and the results of those frequent exchanges impact the value to the owner through focus on attainment of a particular green rating score.These features are confi guring a framework for green project delivery.This framework approaches lean thinking by generating value to the owner,improving the flow of information,and transforming the inputs required for the selection of materials and systems,to outputs in the form of a sustainability rating certification.This research focuses on exploring associations between LEED^(■)criteria,project lifecycle,the stakeholders’interests,lean process improvements and typical delivery systems used in building construction.The paper proposes a matrix of weighted indexes to explain and provide increased collaboration among project participants,improved efficiency throughout the project lifecycle,and new techniques which may be incorporated into the construction process.
