Time delay is an problem of intemet congestion important parameter in the control. According to some researches, time delay is not always constant and can be viewed as a periodic function of time for some cases. In th...Time delay is an problem of intemet congestion important parameter in the control. According to some researches, time delay is not always constant and can be viewed as a periodic function of time for some cases. In this work, an internet congestion control model is consid- ered to study the time-varying delay induced bursting-like motion, which consists of a rapid oscillation burst and quies- cent steady state. Then, for the system with periodic delay of small amplitude and low frequency, the method of multiple scales is employed to obtain the amplitude of the oscillation. Based on the expression of the asymptotic solution, it can be found that the relative length of the steady state increases with amplitude of the variation of time delay and decreases with frequency of the variation of time delay. Finally, an effective method to control the bursting-like motion is pro- posed by introducing a periodic gain parameter with appropriate amplitude. Theoretical results are in agreement with that from numerical method.展开更多
Correlated firings among neurons have been extensively investigated;however,previous studies on retinal ganglion cell(RGC)population activities were mainly based on analyzing the correlated activities between the enti...Correlated firings among neurons have been extensively investigated;however,previous studies on retinal ganglion cell(RGC)population activities were mainly based on analyzing the correlated activities between the entire spike trains.In the present study,the correlation properties were explored based on burst-like activities and solitary spikes separately.The results indicate that:(1)burst-like activities were more correlated with other neurons’activities;(2)burst-like spikes correlated with their neighboring neurons represented a smaller receptive field than that of correlated solitary spikes.These results suggest that correlated burst-like spikes should be more efficient in signal transmission,and could encode more detailed spatial information.展开更多
基金supported by the National Natural Science Foundation of China(11032009)the Fundamental Research Funds for the Central UniversitiesShanghai Leading Academic Discipline Project(B302)
文摘Time delay is an problem of intemet congestion important parameter in the control. According to some researches, time delay is not always constant and can be viewed as a periodic function of time for some cases. In this work, an internet congestion control model is consid- ered to study the time-varying delay induced bursting-like motion, which consists of a rapid oscillation burst and quies- cent steady state. Then, for the system with periodic delay of small amplitude and low frequency, the method of multiple scales is employed to obtain the amplitude of the oscillation. Based on the expression of the asymptotic solution, it can be found that the relative length of the steady state increases with amplitude of the variation of time delay and decreases with frequency of the variation of time delay. Finally, an effective method to control the bursting-like motion is pro- posed by introducing a periodic gain parameter with appropriate amplitude. Theoretical results are in agreement with that from numerical method.
基金supported by the grants from the State Key Basic Research and Development Plan(No.2005CB724301)National Natural Science Foundation of China(Grant No.30670519).
文摘Correlated firings among neurons have been extensively investigated;however,previous studies on retinal ganglion cell(RGC)population activities were mainly based on analyzing the correlated activities between the entire spike trains.In the present study,the correlation properties were explored based on burst-like activities and solitary spikes separately.The results indicate that:(1)burst-like activities were more correlated with other neurons’activities;(2)burst-like spikes correlated with their neighboring neurons represented a smaller receptive field than that of correlated solitary spikes.These results suggest that correlated burst-like spikes should be more efficient in signal transmission,and could encode more detailed spatial information.
