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1. chinaXiv:202109.00058 [pdf]

Subjects: Mathematics >> Applied Mathematics

 In the early days of the epidemic of coronavirus disease 2019 (COVID-19), due to insufficient knowledge of the pandemic, inadequate nucleic acid tests, lack of timely data reporting, etc., the origin time of the onset of COVID-19 is difficult to determine. Therefore, source tracing is crucial for infectious disease prevention and control. The purpose of this paper is to infer the origin time of pandemic of COVID-19 based on a data and model hybrid driven method. We model the testing positive rate to fit its actual trend, and use the least squares estimation to obtain the optimal model parameters. Further, the kernel density estimation is applied to infer the origin time of pandemic given the specific confidence probability. By selecting 12 representative regions in the United States for analysis, the dates of the first infected case with 50% confidence probability are mostly between August and October 2019, which are earlier than the officially announced date of the first confirmed case in the United States on January 20, 2020. The experimental results indicate that the COVID-19 pandemic in the United States starts to spread around September 2019 with a high confidence probability. In addition, the existing confirmed cases are also used in Wuhan City and Zhejiang Province in China to infer the origin time of COVID-19 and provide the confidence probability. The results show that the spread of COVID-19 pandemic in China is likely to begin in late December 2019.

2. chinaXiv:202109.00057 [pdf]

Subjects: Psychology >> Physiological Psychology

 作业中断会对中断后行为绩效产生影响，探讨不同疲劳状态下中断对作业绩效影响的认知机制将有助于完善和发展中断的认知理论。本研究采用事件相关电位(ERP)，通过在不同心理疲劳状态下执行数学题任务中断、暂停中断和不中断的空间2-back任务，结合行为数据和ERPs结果，分析作业中断对任务绩效的影响以及心理疲劳在其中的调节作用。实验结果发现，中断后诱发的P200和P300振幅显著提高，作业中断使得主任务的注意力资源下降，任务中断的无关信息干扰了主任务工作记忆，而疲劳状态则进一步加剧了中断对注意资源、工作记忆及行为绩效的负面效应。本研究在揭示作业中断认知过程及疲劳对其影响机理的同时，也支持了中断的目标记忆模型。