This work aimed to explore the switch tendency of bicycle use between cyclists and non-cyclists.The attitude based market segmentation approach was proposed to achieve the research objective.The filed investigations w...This work aimed to explore the switch tendency of bicycle use between cyclists and non-cyclists.The attitude based market segmentation approach was proposed to achieve the research objective.The filed investigations were conducted in Nanjing,China,to obtain travelers' actions and attitudes towards bicycle uses.The structural equation modeling(SEM) was used to identify the attitudinal factors indicating variables and to explore the interrelationships among them.The SEMs were developed separately for the cyclist group and the non-cyclist group.All respondents were clustered into eight distinct segments by six selected attitudinal factors.The mode switch tendency and attitude in each segment is different from others,indicating that different segments have particular policies or strategies to encourage cycling.Policy implications that best serve the potential bicycle users were discussed to reduce the number of cyclists who have high tendency to use other modes,and increase the possibility of using bicycle in the non-cyclists group with the moderate and high switch tendency.展开更多
This paper studies the consensus problems for a group of agents with switching topology and time-varying communication delays, where the dynamics of agents is modeled as a high-order integrator. A linear distributed c...This paper studies the consensus problems for a group of agents with switching topology and time-varying communication delays, where the dynamics of agents is modeled as a high-order integrator. A linear distributed consensus protocol is proposed, which only depends on the agent＇s own information and its neighbors＇ partial information. By introducing a decomposition of the state vector and performing a state space transformation, the closed-loop dynamics of the multi-agent system is converted into two decoupled subsystems. Based on the decoupled subsystems, some sufficient conditions for the convergence to consensus are established, which provide the upper bounds on the admissible communication delays. Also, the explicit expression of the consensus state is derived. Moreover, the results on the consensus seeking of the group of high-order agents have been extended to a network of agents with dynamics modeled as a completely controllable linear time-invariant system. It is proved that the convergence to consensus of this network is equivalent to that of the group of high-order agents. Finally, some numerical examples are given to demonstrate the effectiveness of the main results.展开更多
This paper mainly investigates dynamics behavior of HIV （human immunodeficiency virus） infectious disease model with switching parameters, and combined bounded noise and Gaussian white noise. This model is different...This paper mainly investigates dynamics behavior of HIV （human immunodeficiency virus） infectious disease model with switching parameters, and combined bounded noise and Gaussian white noise. This model is different from existing HIV models. Based on stochastic Ito lemma and Razumikhin-type approach, some threshold conditions are established to guarantee the disease eradication or persistence. Results show that the smaller amplitude of bounded noise and R0 〈 1 can cause the disease to die out; the disease becomes persistent if R0 〉 1. Moreover, it is found that larger noise intensity suppresses the prevalence of the disease even if R0 〉 1. Some numerical examples are given to verify the obtained results.展开更多
This paper mainly tends to utilize Razumikhin-type theorems to investigate p-th moment stability for a class of stochastic switching nonlinear systems with delay. Based on the Lyapunov-Razumik- hin methods, some suffi...This paper mainly tends to utilize Razumikhin-type theorems to investigate p-th moment stability for a class of stochastic switching nonlinear systems with delay. Based on the Lyapunov-Razumik- hin methods, some sufficient conditions are derived to check the stability of stochastic switching nonlinear systems with delay. One numerical example is provided to demonstrate the effectiveness of the results.展开更多
当前,高频换流器实时仿真在仿真精度和仿真灵活性上难以兼顾。为此采用了基于FPGA+PC的实时多速率协同仿真方法,全面展示了多速率协同仿真系统的仿真原理,以及硬件设计与实现。在30 k Hz/50 k Hz三相两电平逆变算例仿真的研究中,呈现了...当前,高频换流器实时仿真在仿真精度和仿真灵活性上难以兼顾。为此采用了基于FPGA+PC的实时多速率协同仿真方法,全面展示了多速率协同仿真系统的仿真原理,以及硬件设计与实现。在30 k Hz/50 k Hz三相两电平逆变算例仿真的研究中,呈现了换流器建模、算例模型分割和电路求解器实现。以离线精确模型为基准,将多速率协同仿真平台与PC实时仿真平台的实验结果从仿真波形、仿真误差及实时性方面进行比较。结果表明,在开关频率50 k Hz以下多速率仿真的速率转换误差收敛,电磁暂态仿真欧式范数误差达到1%左右,仿真平台仿真步长达到500 ns。该方法提高了高频换流器实时仿真精度、减小了仿真步长,为高性能协同仿真平台的设计提供了参考。展开更多
基金Projects(51208256,51178157)supported by the National Natural Science Foundation of ChinaProject(2012-K5-13)supported by the Ministry of Housing and Urban-Rural Development of China
文摘This work aimed to explore the switch tendency of bicycle use between cyclists and non-cyclists.The attitude based market segmentation approach was proposed to achieve the research objective.The filed investigations were conducted in Nanjing,China,to obtain travelers' actions and attitudes towards bicycle uses.The structural equation modeling(SEM) was used to identify the attitudinal factors indicating variables and to explore the interrelationships among them.The SEMs were developed separately for the cyclist group and the non-cyclist group.All respondents were clustered into eight distinct segments by six selected attitudinal factors.The mode switch tendency and attitude in each segment is different from others,indicating that different segments have particular policies or strategies to encourage cycling.Policy implications that best serve the potential bicycle users were discussed to reduce the number of cyclists who have high tendency to use other modes,and increase the possibility of using bicycle in the non-cyclists group with the moderate and high switch tendency.
基金supported by the National Natural Science Foundation of China(No.60674050,60736022,10972002,60774089,60704039)
文摘This paper studies the consensus problems for a group of agents with switching topology and time-varying communication delays, where the dynamics of agents is modeled as a high-order integrator. A linear distributed consensus protocol is proposed, which only depends on the agent＇s own information and its neighbors＇ partial information. By introducing a decomposition of the state vector and performing a state space transformation, the closed-loop dynamics of the multi-agent system is converted into two decoupled subsystems. Based on the decoupled subsystems, some sufficient conditions for the convergence to consensus are established, which provide the upper bounds on the admissible communication delays. Also, the explicit expression of the consensus state is derived. Moreover, the results on the consensus seeking of the group of high-order agents have been extended to a network of agents with dynamics modeled as a completely controllable linear time-invariant system. It is proved that the convergence to consensus of this network is equivalent to that of the group of high-order agents. Finally, some numerical examples are given to demonstrate the effectiveness of the main results.
基金supported by the National Natural Science Foundation of China(Grant Nos.11172233,11472212,11272258,and 11302170)the Natural Science and Engineering Research Council of Canada(NSERC)
文摘This paper mainly investigates dynamics behavior of HIV （human immunodeficiency virus） infectious disease model with switching parameters, and combined bounded noise and Gaussian white noise. This model is different from existing HIV models. Based on stochastic Ito lemma and Razumikhin-type approach, some threshold conditions are established to guarantee the disease eradication or persistence. Results show that the smaller amplitude of bounded noise and R0 〈 1 can cause the disease to die out; the disease becomes persistent if R0 〉 1. Moreover, it is found that larger noise intensity suppresses the prevalence of the disease even if R0 〉 1. Some numerical examples are given to verify the obtained results.
文摘This paper mainly tends to utilize Razumikhin-type theorems to investigate p-th moment stability for a class of stochastic switching nonlinear systems with delay. Based on the Lyapunov-Razumik- hin methods, some sufficient conditions are derived to check the stability of stochastic switching nonlinear systems with delay. One numerical example is provided to demonstrate the effectiveness of the results.
文摘当前,高频换流器实时仿真在仿真精度和仿真灵活性上难以兼顾。为此采用了基于FPGA+PC的实时多速率协同仿真方法,全面展示了多速率协同仿真系统的仿真原理,以及硬件设计与实现。在30 k Hz/50 k Hz三相两电平逆变算例仿真的研究中,呈现了换流器建模、算例模型分割和电路求解器实现。以离线精确模型为基准,将多速率协同仿真平台与PC实时仿真平台的实验结果从仿真波形、仿真误差及实时性方面进行比较。结果表明,在开关频率50 k Hz以下多速率仿真的速率转换误差收敛,电磁暂态仿真欧式范数误差达到1%左右,仿真平台仿真步长达到500 ns。该方法提高了高频换流器实时仿真精度、减小了仿真步长,为高性能协同仿真平台的设计提供了参考。
