In order to prevent and control the spread of rumors, the implementation of immunization strategies for ignorant individuals is very necessary, where the immunization usually means letting them learn the truth of rumo...In order to prevent and control the spread of rumors, the implementation of immunization strategies for ignorant individuals is very necessary, where the immunization usually means letting them learn the truth of rumors.Considering the facts that there is always a delay time between rumor spreading and implementing immunization, and that the truth of rumors can also be spread out, this paper constructs a novel susceptible-infected-removed(SIR) model.The propagation dynamical behaviors of the SIR model on homogeneous networks are investigated by using the meanfield theory and the Monte Carlo method. Research shows that the greater the delay time, the worse the immune effect of the immunization strategy. It is also found that the spread of the truth can inhibit to some extent the propagation of rumors, and the trend will become more obvious with the increase of reliability of the truth. Moreover, under the influence of delay time, the existence of nodes' identification force still slightly reduces the propagation degree of rumors.展开更多
采用FPGA芯片进行数字信号处理时常需要数控振荡器(Numeric Control Oscillator,NCO)产生各种不同频率的时钟,然而随着工程中对NCO的工作频率需求的提高,实现NCO的加法器将会有过长的进位链,这样就限制了加法器的运行频率不能过高。为...采用FPGA芯片进行数字信号处理时常需要数控振荡器(Numeric Control Oscillator,NCO)产生各种不同频率的时钟,然而随着工程中对NCO的工作频率需求的提高,实现NCO的加法器将会有过长的进位链,这样就限制了加法器的运行频率不能过高。为了解决这一限制与需求的矛盾,采用一种基于预进位链优化的改进方法。经过对无预进位NCO、一级预进位NCO和二级预进位NCO的时序分析和实测数据进行对比,结果表明这种方法产生的NCO频率指标满足设计要求,可以将NCO的工作频率提高70.53%。展开更多
The architecture of carry chains in Field-Programmable Gate Array(FPGA) is introduced in this paper. The propagation delay time of the rising and falling edges in the carry chains are calculated according to the archi...The architecture of carry chains in Field-Programmable Gate Array(FPGA) is introduced in this paper. The propagation delay time of the rising and falling edges in the carry chains are calculated according to the architecture and they are predicted not equal in most cases. Tests show that the measuring results of the propagation delay time in EP3C120F484C8 N series FPGA of Altera are in line with the inference. The difference of propagation delay time results in different accuracies of Time-to-Digital Converter(TDC). This phenomenon shall be considered in the design of TDC implemented in FPGA. It can ensure better accuracy.展开更多
基金Projects(U21A20107, 52074239, 52174135) supported by National Natural Science Foundation of ChinaProjects(2022WLKXJ047, KYCX22_2617) supported by the Graduate Innovation Program and Postgraduate Research & Practice Innovation Program of Jiangsu Province, ChinaProject(NRF-2021R1A2C3011490) supported by the National Research Foundation of Korea。
基金Supported by the National Natural Science Foundation of China under Grant No.61402531the Natural Science Basic Research Plan in Shaanxi Province of China under Grant Nos.2014JQ8358,2015JQ6231,and 2014JQ8307+1 种基金the China Postdoctoral Science Foundation under Grant No.2015M582910the Basic Research Foundation of Engineering University of the Chinese People’s Armed Police Force under Grant Nos.WJY201419,WJY201605 and JLX201686
文摘In order to prevent and control the spread of rumors, the implementation of immunization strategies for ignorant individuals is very necessary, where the immunization usually means letting them learn the truth of rumors.Considering the facts that there is always a delay time between rumor spreading and implementing immunization, and that the truth of rumors can also be spread out, this paper constructs a novel susceptible-infected-removed(SIR) model.The propagation dynamical behaviors of the SIR model on homogeneous networks are investigated by using the meanfield theory and the Monte Carlo method. Research shows that the greater the delay time, the worse the immune effect of the immunization strategy. It is also found that the spread of the truth can inhibit to some extent the propagation of rumors, and the trend will become more obvious with the increase of reliability of the truth. Moreover, under the influence of delay time, the existence of nodes' identification force still slightly reduces the propagation degree of rumors.
文摘采用FPGA芯片进行数字信号处理时常需要数控振荡器(Numeric Control Oscillator,NCO)产生各种不同频率的时钟,然而随着工程中对NCO的工作频率需求的提高,实现NCO的加法器将会有过长的进位链,这样就限制了加法器的运行频率不能过高。为了解决这一限制与需求的矛盾,采用一种基于预进位链优化的改进方法。经过对无预进位NCO、一级预进位NCO和二级预进位NCO的时序分析和实测数据进行对比,结果表明这种方法产生的NCO频率指标满足设计要求,可以将NCO的工作频率提高70.53%。
文摘The architecture of carry chains in Field-Programmable Gate Array(FPGA) is introduced in this paper. The propagation delay time of the rising and falling edges in the carry chains are calculated according to the architecture and they are predicted not equal in most cases. Tests show that the measuring results of the propagation delay time in EP3C120F484C8 N series FPGA of Altera are in line with the inference. The difference of propagation delay time results in different accuracies of Time-to-Digital Converter(TDC). This phenomenon shall be considered in the design of TDC implemented in FPGA. It can ensure better accuracy.
