Since 1991, air pollution has gained special attention in Taiwan after a petrochemical complex was constructed in Mailiao Township, Yunlin County. We explored the association between the magnitude of PM2.5 and meteoro...Since 1991, air pollution has gained special attention in Taiwan after a petrochemical complex was constructed in Mailiao Township, Yunlin County. We explored the association between the magnitude of PM2.5 and meteorological factors during 2012-2016. Our findings revealed that 1) mean PM2.5 levels gradually decreased from 30.70 μg/m3 in 2013 to 25.36 μg/m3 in 2016;2) wind speed is the main determinant of air quality—air quality significantly improved when it was faster than 4 m/sec;and 3) wind direction is another determinant of air quality—when the wind direction was southerly, air quality improved. Elevated PM2.5 levels were defined as those hourly levels higher than the third quartile (36 μg/m3). The significantly negative predictive factors for elevated PM2.5 levels were the summer or autumn seasons, rainfall, increased wind speed, and wind direction from 150° to 230° from the north. The significantly positive predictive factors for elevated PM2.5 levels were working hours from 6 a.m. to 2 p.m., a temperature between 11°C and 25°C, relative humidity between 40% and 68%, and wind direction (e.g., northerly wind, northeasterly wind, and easterly wind). The predictive formula is attached in the Appendix. Therefore, people should protect themselves on these high-risk days.展开更多
The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes th...The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes the data source of index. Secondly, the weight of index is determined and the fuzzy comprehensive evaluation model is proposed. Finally, results of instance analysis show that the evaluation model is feasible and effective.展开更多
With an increasing urgent demand for fast recovery routing mechanisms in large-scale networks,minimizing network disruption caused by network failure has become critical.However,a large number of relevant studies have...With an increasing urgent demand for fast recovery routing mechanisms in large-scale networks,minimizing network disruption caused by network failure has become critical.However,a large number of relevant studies have shown that network failures occur on the Internet inevitably and frequently.The current routing protocols deployed on the Internet adopt the reconvergence mechanism to cope with network failures.During the reconvergence process,the packets may be lost because of inconsistent routing information,which reduces the network’s availability greatly and affects the Internet service provider’s(ISP’s)service quality and reputation seriously.Therefore,improving network availability has become an urgent problem.As such,the Internet Engineering Task Force suggests the use of downstream path criterion(DC)to address all single-link failure scenarios.However,existing methods for implementing DC schemes are time consuming,require a large amount of router CPU resources,and may deteriorate router capability.Thus,the computation overhead introduced by existing DC schemes is significant,especially in large-scale networks.Therefore,this study proposes an efficient intra-domain routing protection algorithm(ERPA)in large-scale networks.Theoretical analysis indicates that the time complexity of ERPA is less than that of constructing a shortest path tree.Experimental results show that ERPA can reduce the computation overhead significantly compared with the existing algorithms while offering the same network availability as DC.展开更多
Through analysis of satellite images from Google Earth, this article expounds the characteristics of large-scale geomorphic patterns of the complex longitudinal sand ridge zone in the Taklimakan Desert, and reduces th...Through analysis of satellite images from Google Earth, this article expounds the characteristics of large-scale geomorphic patterns of the complex longitudinal sand ridge zone in the Taklimakan Desert, and reduces the large-scale geomorphic patterns to six types: parallel pattern, "日"character-shaped and "乡" character-shaped pattern, comb-shaped pattern, fork-shaped pattern, toe-shaped pattern and miscellaneous pattern. And according to the large-scale geomorphic pattern type (or composition of pattern types) as well as some other factors, the article divides the complex longitudinal sand ridge zone into 55 subzones. Lastly, aiming at the genetic problems of the large-scale geomorphic patterns, the article suggests three connective types of the sand ridges in the complex longitudinal sand ridge zone, i.e., connecting or intersecting after natural elongation, connecting in a narrow place and connecting with the aid of intermediary.展开更多
文摘Since 1991, air pollution has gained special attention in Taiwan after a petrochemical complex was constructed in Mailiao Township, Yunlin County. We explored the association between the magnitude of PM2.5 and meteorological factors during 2012-2016. Our findings revealed that 1) mean PM2.5 levels gradually decreased from 30.70 μg/m3 in 2013 to 25.36 μg/m3 in 2016;2) wind speed is the main determinant of air quality—air quality significantly improved when it was faster than 4 m/sec;and 3) wind direction is another determinant of air quality—when the wind direction was southerly, air quality improved. Elevated PM2.5 levels were defined as those hourly levels higher than the third quartile (36 μg/m3). The significantly negative predictive factors for elevated PM2.5 levels were the summer or autumn seasons, rainfall, increased wind speed, and wind direction from 150° to 230° from the north. The significantly positive predictive factors for elevated PM2.5 levels were working hours from 6 a.m. to 2 p.m., a temperature between 11°C and 25°C, relative humidity between 40% and 68%, and wind direction (e.g., northerly wind, northeasterly wind, and easterly wind). The predictive formula is attached in the Appendix. Therefore, people should protect themselves on these high-risk days.
基金supported by the Natural Science Foundation of China(71704184)Projects of the of the National Social Science Foundation of China(15GJ003-245)Science Foundation of Equipment Research(JJ20172A05095)
文摘The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes the data source of index. Secondly, the weight of index is determined and the fuzzy comprehensive evaluation model is proposed. Finally, results of instance analysis show that the evaluation model is feasible and effective.
基金the National Natural Science Foundation of China(No.61702315)the Key R&D program(international science and technology cooperation project)of Shanxi Province China(No.201903D421003)the National Key Research and Development Program of China(No.2018YFB1800401).
文摘With an increasing urgent demand for fast recovery routing mechanisms in large-scale networks,minimizing network disruption caused by network failure has become critical.However,a large number of relevant studies have shown that network failures occur on the Internet inevitably and frequently.The current routing protocols deployed on the Internet adopt the reconvergence mechanism to cope with network failures.During the reconvergence process,the packets may be lost because of inconsistent routing information,which reduces the network’s availability greatly and affects the Internet service provider’s(ISP’s)service quality and reputation seriously.Therefore,improving network availability has become an urgent problem.As such,the Internet Engineering Task Force suggests the use of downstream path criterion(DC)to address all single-link failure scenarios.However,existing methods for implementing DC schemes are time consuming,require a large amount of router CPU resources,and may deteriorate router capability.Thus,the computation overhead introduced by existing DC schemes is significant,especially in large-scale networks.Therefore,this study proposes an efficient intra-domain routing protection algorithm(ERPA)in large-scale networks.Theoretical analysis indicates that the time complexity of ERPA is less than that of constructing a shortest path tree.Experimental results show that ERPA can reduce the computation overhead significantly compared with the existing algorithms while offering the same network availability as DC.
基金Supported by Major Orientation Foundation of the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX3-SW-342)
文摘Through analysis of satellite images from Google Earth, this article expounds the characteristics of large-scale geomorphic patterns of the complex longitudinal sand ridge zone in the Taklimakan Desert, and reduces the large-scale geomorphic patterns to six types: parallel pattern, "日"character-shaped and "乡" character-shaped pattern, comb-shaped pattern, fork-shaped pattern, toe-shaped pattern and miscellaneous pattern. And according to the large-scale geomorphic pattern type (or composition of pattern types) as well as some other factors, the article divides the complex longitudinal sand ridge zone into 55 subzones. Lastly, aiming at the genetic problems of the large-scale geomorphic patterns, the article suggests three connective types of the sand ridges in the complex longitudinal sand ridge zone, i.e., connecting or intersecting after natural elongation, connecting in a narrow place and connecting with the aid of intermediary.