针对混合攻击下的一类新型电力系统,本文提出了一种负荷频率安全控制方案,实现在欺骗与拒绝服务(denial of service,DoS)攻击下的闭环稳定与安全运行.首先,基于确认字符(acknowledgement character,ACK)技术提出了一种针对非周期性DoS...针对混合攻击下的一类新型电力系统,本文提出了一种负荷频率安全控制方案,实现在欺骗与拒绝服务(denial of service,DoS)攻击下的闭环稳定与安全运行.首先,基于确认字符(acknowledgement character,ACK)技术提出了一种针对非周期性DoS攻击的“阴阳”检测机制.其次,为保持系统控制性能并节约网络通信资源,提出了一种新颖的带宽感知事件触发机制.再次,建立了一个混合攻击下包含风力发电机组与电池储能系统的多区域电力系统切换模型.利用Lyapunov-Krasovskii泛函(Lyapunov-Krasovskii functional,LKF)理论与线性矩阵不等式(linear matrix inequality,LMI)技术,给出满足H∞性能的系统指数均方稳定充分条件,并导出了事件触发负荷频率安全控制器的设计准则.最后,通过仿真实验验证了所提DoS攻击检测机制和事件触发安全控制器的有效性与优越性.展开更多
Objective:Correctly understanding and evaluating the level of public risk perception toward public health emergencies not only helps experts and decision-makers understand the public’s preventative health behaviors t...Objective:Correctly understanding and evaluating the level of public risk perception toward public health emergencies not only helps experts and decision-makers understand the public’s preventative health behaviors to these emergencies but also enhances their risk information communication with the public.The aim of this study was to develop a risk perception scale for public health emergencies and test its validity and reliability during the coronavirus disease 2019(COVID-19)pandemic.Methods:Guided by the theoretical model of risk perception,an initial scale was generated through literature review,group meetings,resident interviews,and expert consultation.A pretest and item screening were then conducted to develop a formal risk perception scale for public health emergencies.Finally,the reliability and validity of the scale were validated through a questionnaire survey of 504 Chinese adults.Results:The final scale had 9 items.The content validity index of the scale was 0.968,and the content validity index of individual items ranged from 0.83 to 1.00.Three common factors,dread risk perception,severe risk perception,and unknown risk perception,were extracted for exploratory factor analysis,and together they explained 66.26%of the variance in the score.Confirmatory factor analysis showed that the model had a satisfactory fit,whereχ^(2)/df=1.384,the goodness-of-fit index(GFI)=0.989,root mean square error of approximation(RMSEA)=0.028,root mean square residual(RMR)=0.018,comparative fit index(CFI)=0.995,normed fit index(NFI)=0.982,and non-normed fit index(NNFI)=0.990.The correlations between dimensions ranged from 0.306 to 0.483(P<0.01).Cronbach’s a was 0.793 for the total scale and ranged between 0.687 and 0.801 for the individual dimensions.The split-half coefficient was 0.861 for the total scale and ranged from 0.727 to 0.856 for induvial dimensions.The test-retest coefficient was 0.846 for the total scale and ranged from 0.843 to 0.868 for induvial dimensions.Conclusion:The developed scale for the risk perception of public health emergencies showed acceptable levels of reliability and validity,suggesting that it is suitable for evaluating residents’risk perception of public health emergencies.展开更多
文摘Objective:Correctly understanding and evaluating the level of public risk perception toward public health emergencies not only helps experts and decision-makers understand the public’s preventative health behaviors to these emergencies but also enhances their risk information communication with the public.The aim of this study was to develop a risk perception scale for public health emergencies and test its validity and reliability during the coronavirus disease 2019(COVID-19)pandemic.Methods:Guided by the theoretical model of risk perception,an initial scale was generated through literature review,group meetings,resident interviews,and expert consultation.A pretest and item screening were then conducted to develop a formal risk perception scale for public health emergencies.Finally,the reliability and validity of the scale were validated through a questionnaire survey of 504 Chinese adults.Results:The final scale had 9 items.The content validity index of the scale was 0.968,and the content validity index of individual items ranged from 0.83 to 1.00.Three common factors,dread risk perception,severe risk perception,and unknown risk perception,were extracted for exploratory factor analysis,and together they explained 66.26%of the variance in the score.Confirmatory factor analysis showed that the model had a satisfactory fit,whereχ^(2)/df=1.384,the goodness-of-fit index(GFI)=0.989,root mean square error of approximation(RMSEA)=0.028,root mean square residual(RMR)=0.018,comparative fit index(CFI)=0.995,normed fit index(NFI)=0.982,and non-normed fit index(NNFI)=0.990.The correlations between dimensions ranged from 0.306 to 0.483(P<0.01).Cronbach’s a was 0.793 for the total scale and ranged between 0.687 and 0.801 for the individual dimensions.The split-half coefficient was 0.861 for the total scale and ranged from 0.727 to 0.856 for induvial dimensions.The test-retest coefficient was 0.846 for the total scale and ranged from 0.843 to 0.868 for induvial dimensions.Conclusion:The developed scale for the risk perception of public health emergencies showed acceptable levels of reliability and validity,suggesting that it is suitable for evaluating residents’risk perception of public health emergencies.
