Based on previous research work,we present a spectrum deviation method to recognize a foreshock or generalized foreshock in this paper. The criterion to determine whether an event is a foreshock is a wide spectrum for...Based on previous research work,we present a spectrum deviation method to recognize a foreshock or generalized foreshock in this paper. The criterion to determine whether an event is a foreshock is a wide spectrum for an ordinary event,however,a moderate earthquake with foreshock or generalized foreshock has the characteristics of a narrow frequency band,and it deviates to the low frequency. It may be explained by metastable extension in the rupture source or related area of the main shock or regional fragmentation damage and crack nucleation process. The calculation results of two foreshocks,the M_S4. 7 event which occurred before the Yushu M_S7. 1 earthquake on April 14,2010 and the M_S5. 3 event which occurred before the Yutian M_S7. 3 earthquake on February 12,2014,show that the spectra of foreshocks shift,and they are quite different from the nonforeshock seismic spectrum of equivalent size. Therefore,this result can verify the validity of the spectrum deviation method.展开更多
The moving-mean method is one of the conventional approaches for trend-extraction from a data set. It is usually applied in an empirical way. The smoothing degree of the trend depends on the selections of window lengt...The moving-mean method is one of the conventional approaches for trend-extraction from a data set. It is usually applied in an empirical way. The smoothing degree of the trend depends on the selections of window length and weighted coefficients, which are associated with the change pattern of the data. Are there any uniform criteria for determining them? The present article is a reaction to this fundamental problem. By investigating many kinds of data, the results show that: 1) Within a certain range, the more points which participate in moving-mean, the better the trend function. However, in case the window length is too long, the trend function may tend to the ordinary global mean. 2) For a given window length, what matters is the choice of weighted coefficients. As the five-point case concerned, the local-midpoint, local-mean and global-mean criteria hold. Among these three criteria, the local-mean one has the strongest adaptability, which is suggested for your usage.展开更多
The application of frequency distribution statistics to data provides objective means to assess the nature of the data distribution and viability of numerical models that are used to visualize and interpret data.Two c...The application of frequency distribution statistics to data provides objective means to assess the nature of the data distribution and viability of numerical models that are used to visualize and interpret data.Two commonly used tools are the kernel density estimation and reduced chi-squared statistic used in combination with a weighted mean.Due to the wide applicability of these tools,we present a Java-based computer application called KDX to facilitate the visualization of data and the utilization of these numerical tools.展开更多
In the measurement of liquid level in industrial site environment,noise interference can affect the measurement accuracy.In order to improve the measurement accuracy of liquid level in the viscous state,a nuclear radi...In the measurement of liquid level in industrial site environment,noise interference can affect the measurement accuracy.In order to improve the measurement accuracy of liquid level in the viscous state,a nuclear radiation level measurement system based on the least mean square(LMS)filtering correction method is designed.The system uses STM32F103 as the control core and adopts HART bus HT1200M chip for remote signal transmission and reception.The adaptive LMS algorithm can be used for more accurate filtering,calculating iterative weight vector,updating weighted coefficient,effectively removing system measurement noise and improving the measurement accuracy.The results show that the nuclear radiation level gauge based on normalized LMS can correct the measurement system accuracy in adaptive rules,improve the measurement accuracy to meet the requirements of industrial field environment for liquid level measurement and enhance the industrial automation control degree.展开更多
高水平体育赛事已成为体育事业发展的重要助推手段和城市软实力展示的重要媒介,受到了全世界的重视。面对频繁举办的各类体育赛事,其竞争力评价对城市、主办者、参与者都具有重要意义。为科学评价我国体育赛事的竞争力水平,从基础竞争...高水平体育赛事已成为体育事业发展的重要助推手段和城市软实力展示的重要媒介,受到了全世界的重视。面对频繁举办的各类体育赛事,其竞争力评价对城市、主办者、参与者都具有重要意义。为科学评价我国体育赛事的竞争力水平,从基础竞争力和核心竞争力两个子系统出发构建马拉松赛事竞争力评价指标体系,采用结构熵权法和均方差决策法进行主客观联合赋权,并以我国13个顶级马拉松赛事为例,完成其竞争力综合评价的实证研究。研究发现:(1)经本研究构建评价指标体系实证所得出的我国顶级马拉松赛事竞争力排序与Ga WC(Globalization and World Cities)组织的世界城市排名结果具有较高匹配度,且这一结果较好契合现状认知,表明该评价指标体系和方法可为其他同类体育赛事竞争力的评价研究提供借鉴。(2)实证中马拉松赛事的基础竞争力与举办城市本身的社会经济实力密切相关,香港、北京、上海和广州等国际一流城市举办的马拉松赛事基础竞争力远远高于衡水等欠发达城市。(3)总体上第三方参度与和赛事水平在马拉松赛事核心竞争力中起着关键作用,台北、厦门、兰州等经济总量不大或中等偏上的城市马拉松赛事的核心竞争力排名比较靠前。(4)我国顶级马拉松赛事的综合竞争力排名从高到低为:香港、北京、广州、台北、上海、杭州、兰州、重庆、厦门、太原、深圳、东营和衡水。(5)我国顶级马拉松赛事竞争力可分为五个等级:香港、北京、广州和上海的马拉松赛事为高水平均衡型;台北和兰州的马拉松赛事为高水平单一型;杭州、重庆、太原和深圳的马拉松赛事为中等水平均衡型;厦门和东营的马拉松赛事为中等水平单一型;衡水马拉松赛事为低水平单一型。等级划分基础上还针对政府、组织者和参与者提出了发展运营、赛事组织、参与选择等方面的对策建议。展开更多
基金sponsored by the National Key Technology Support Program of China entitled "Application of Digital Seismic Technology to Mid-and Short-term Prediction of Strong Earthquake"(2012BAK19B02-01)
文摘Based on previous research work,we present a spectrum deviation method to recognize a foreshock or generalized foreshock in this paper. The criterion to determine whether an event is a foreshock is a wide spectrum for an ordinary event,however,a moderate earthquake with foreshock or generalized foreshock has the characteristics of a narrow frequency band,and it deviates to the low frequency. It may be explained by metastable extension in the rupture source or related area of the main shock or regional fragmentation damage and crack nucleation process. The calculation results of two foreshocks,the M_S4. 7 event which occurred before the Yushu M_S7. 1 earthquake on April 14,2010 and the M_S5. 3 event which occurred before the Yutian M_S7. 3 earthquake on February 12,2014,show that the spectra of foreshocks shift,and they are quite different from the nonforeshock seismic spectrum of equivalent size. Therefore,this result can verify the validity of the spectrum deviation method.
文摘The moving-mean method is one of the conventional approaches for trend-extraction from a data set. It is usually applied in an empirical way. The smoothing degree of the trend depends on the selections of window length and weighted coefficients, which are associated with the change pattern of the data. Are there any uniform criteria for determining them? The present article is a reaction to this fundamental problem. By investigating many kinds of data, the results show that: 1) Within a certain range, the more points which participate in moving-mean, the better the trend function. However, in case the window length is too long, the trend function may tend to the ordinary global mean. 2) For a given window length, what matters is the choice of weighted coefficients. As the five-point case concerned, the local-midpoint, local-mean and global-mean criteria hold. Among these three criteria, the local-mean one has the strongest adaptability, which is suggested for your usage.
文摘The application of frequency distribution statistics to data provides objective means to assess the nature of the data distribution and viability of numerical models that are used to visualize and interpret data.Two commonly used tools are the kernel density estimation and reduced chi-squared statistic used in combination with a weighted mean.Due to the wide applicability of these tools,we present a Java-based computer application called KDX to facilitate the visualization of data and the utilization of these numerical tools.
基金National Natural Science Foundation of China(Nos.61761027,61261029)
文摘In the measurement of liquid level in industrial site environment,noise interference can affect the measurement accuracy.In order to improve the measurement accuracy of liquid level in the viscous state,a nuclear radiation level measurement system based on the least mean square(LMS)filtering correction method is designed.The system uses STM32F103 as the control core and adopts HART bus HT1200M chip for remote signal transmission and reception.The adaptive LMS algorithm can be used for more accurate filtering,calculating iterative weight vector,updating weighted coefficient,effectively removing system measurement noise and improving the measurement accuracy.The results show that the nuclear radiation level gauge based on normalized LMS can correct the measurement system accuracy in adaptive rules,improve the measurement accuracy to meet the requirements of industrial field environment for liquid level measurement and enhance the industrial automation control degree.
文摘高水平体育赛事已成为体育事业发展的重要助推手段和城市软实力展示的重要媒介,受到了全世界的重视。面对频繁举办的各类体育赛事,其竞争力评价对城市、主办者、参与者都具有重要意义。为科学评价我国体育赛事的竞争力水平,从基础竞争力和核心竞争力两个子系统出发构建马拉松赛事竞争力评价指标体系,采用结构熵权法和均方差决策法进行主客观联合赋权,并以我国13个顶级马拉松赛事为例,完成其竞争力综合评价的实证研究。研究发现:(1)经本研究构建评价指标体系实证所得出的我国顶级马拉松赛事竞争力排序与Ga WC(Globalization and World Cities)组织的世界城市排名结果具有较高匹配度,且这一结果较好契合现状认知,表明该评价指标体系和方法可为其他同类体育赛事竞争力的评价研究提供借鉴。(2)实证中马拉松赛事的基础竞争力与举办城市本身的社会经济实力密切相关,香港、北京、上海和广州等国际一流城市举办的马拉松赛事基础竞争力远远高于衡水等欠发达城市。(3)总体上第三方参度与和赛事水平在马拉松赛事核心竞争力中起着关键作用,台北、厦门、兰州等经济总量不大或中等偏上的城市马拉松赛事的核心竞争力排名比较靠前。(4)我国顶级马拉松赛事的综合竞争力排名从高到低为:香港、北京、广州、台北、上海、杭州、兰州、重庆、厦门、太原、深圳、东营和衡水。(5)我国顶级马拉松赛事竞争力可分为五个等级:香港、北京、广州和上海的马拉松赛事为高水平均衡型;台北和兰州的马拉松赛事为高水平单一型;杭州、重庆、太原和深圳的马拉松赛事为中等水平均衡型;厦门和东营的马拉松赛事为中等水平单一型;衡水马拉松赛事为低水平单一型。等级划分基础上还针对政府、组织者和参与者提出了发展运营、赛事组织、参与选择等方面的对策建议。
