What is already known about this topic?The investigations and analyses limited to epidemiological characteristics are insufficient to analyze the spread patterns of norovirus outbreaks in schools.What is added by this...What is already known about this topic?The investigations and analyses limited to epidemiological characteristics are insufficient to analyze the spread patterns of norovirus outbreaks in schools.What is added by this report?Norovirus outbreaks in primary schools are a dynamic process that spreads through social networks.The use of a social network analysis method to measure and identify key nodes for simulating control evolution was proven effective.What are the implications for public health practice?Infected students exhibit priority connection characteristics at different developmental stages in the network topology.Identifying and deliberately targeting key nodes could destroy network connectivity and help reduce the spread of the outbreak.展开更多
Matrix-vector multiplication is the key operation for many computationally intensive algorithms. The emerging metal oxide resistive switching random access memory （RRAM） device and RRAM crossbar array have demonstra...Matrix-vector multiplication is the key operation for many computationally intensive algorithms. The emerging metal oxide resistive switching random access memory （RRAM） device and RRAM crossbar array have demonstrated a promising hardware realization of the analog matrix-vector multiplication with ultra-high energy efficiency. In this paper, we analyze the impact of both device level and circuit level non-ideal factors, including the nonlinear current-voltage relationship of RRAM devices, the variation of device fabrication and write operation, and the interconnect resistance as well as other crossbar array parameters. On top of that, we propose a technological exploration flow for device parameter configuration to overcome the impact of non-ideal factors and achieve a better trade-off among performance, energy, and reliability for each specific application. Our simulation results of a support vector machine （SVM） and Mixed National Institute of Standards and Technology （MNIST） pattern recognition dataset show that RRAM crossbar array based SVM is robust to input signal fluctuation but sensitive to tunneling gap deviation. A further resistance resolution test presents that a 6-bit RRAM device is able to realize a recognition accuracy around 90%, indicating the physical feasibility of RRAM crossbar array based SVM. In addition, the proposed technological exploration flow is able to achieve 10.98% improvement of recognition accuracy on the MNIST dataset and 26.4% energy savings compared with previous work. Experimental results also show that more than 84.4% power saving can be achieved at the cost of little accuracy reduction.展开更多
On January 13,2022,Zhuhai CDC received a notification that a coronavirus disease 2019(COVID-19)case was found in the fever clinic in nearby Zhongshan City.Zhuhai CDC promptly carried out large-scale population screeni...On January 13,2022,Zhuhai CDC received a notification that a coronavirus disease 2019(COVID-19)case was found in the fever clinic in nearby Zhongshan City.Zhuhai CDC promptly carried out large-scale population screening in three nearby counties.A total of 4 COVID-19 cases were found in Nanping County.34 cases were screened from close contacts,and 2 cases were reported from close contacts in other cities of Guangdong Province.The 20 cases were sequenced by Guangdong CDC and identified as the variant of concern(VOC)/Omicron variant BA.1.Since January 14,Zhuhai has carried out 8 rounds of nucleic acid screening for COVID-19 in the county where the cases occurred.Four large-scale nucleic acid screening tests for COVID-19 were conducted across the city,and no new community cases were reported after January 15.展开更多
基金Supported by the Medical Science and Technology Research Fund Project of Guangdong Province(A2021021).
文摘What is already known about this topic?The investigations and analyses limited to epidemiological characteristics are insufficient to analyze the spread patterns of norovirus outbreaks in schools.What is added by this report?Norovirus outbreaks in primary schools are a dynamic process that spreads through social networks.The use of a social network analysis method to measure and identify key nodes for simulating control evolution was proven effective.What are the implications for public health practice?Infected students exhibit priority connection characteristics at different developmental stages in the network topology.Identifying and deliberately targeting key nodes could destroy network connectivity and help reduce the spread of the outbreak.
基金This work was supported by the National Basic Research 973 Program of China under Grant No. 2013CB329000, the National Natural Science Foundation of China under Grant Nos. 61373026, 61261160501, the Brain Inspired Computing Research of Tsinghua University under Grant No. 20141080934, Tsinghua University Initiative Scientific Research Program, and the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions.
文摘Matrix-vector multiplication is the key operation for many computationally intensive algorithms. The emerging metal oxide resistive switching random access memory （RRAM） device and RRAM crossbar array have demonstrated a promising hardware realization of the analog matrix-vector multiplication with ultra-high energy efficiency. In this paper, we analyze the impact of both device level and circuit level non-ideal factors, including the nonlinear current-voltage relationship of RRAM devices, the variation of device fabrication and write operation, and the interconnect resistance as well as other crossbar array parameters. On top of that, we propose a technological exploration flow for device parameter configuration to overcome the impact of non-ideal factors and achieve a better trade-off among performance, energy, and reliability for each specific application. Our simulation results of a support vector machine （SVM） and Mixed National Institute of Standards and Technology （MNIST） pattern recognition dataset show that RRAM crossbar array based SVM is robust to input signal fluctuation but sensitive to tunneling gap deviation. A further resistance resolution test presents that a 6-bit RRAM device is able to realize a recognition accuracy around 90%, indicating the physical feasibility of RRAM crossbar array based SVM. In addition, the proposed technological exploration flow is able to achieve 10.98% improvement of recognition accuracy on the MNIST dataset and 26.4% energy savings compared with previous work. Experimental results also show that more than 84.4% power saving can be achieved at the cost of little accuracy reduction.
基金Zhuhai Science and Technology Program(ZH22036302200077PWC).
文摘On January 13,2022,Zhuhai CDC received a notification that a coronavirus disease 2019(COVID-19)case was found in the fever clinic in nearby Zhongshan City.Zhuhai CDC promptly carried out large-scale population screening in three nearby counties.A total of 4 COVID-19 cases were found in Nanping County.34 cases were screened from close contacts,and 2 cases were reported from close contacts in other cities of Guangdong Province.The 20 cases were sequenced by Guangdong CDC and identified as the variant of concern(VOC)/Omicron variant BA.1.Since January 14,Zhuhai has carried out 8 rounds of nucleic acid screening for COVID-19 in the county where the cases occurred.Four large-scale nucleic acid screening tests for COVID-19 were conducted across the city,and no new community cases were reported after January 15.
