强制进化随机游走算法(random walk algorithm with compulsive evolution,RWCE)具有进化策略简单、控制参数少、全局搜索能力强等特点,是换热网络优化的一种有效方法。鉴于步长对RWCE算法跳出局部最优解有重要的影响,针对RWCE算法的步...强制进化随机游走算法(random walk algorithm with compulsive evolution,RWCE)具有进化策略简单、控制参数少、全局搜索能力强等特点,是换热网络优化的一种有效方法。鉴于步长对RWCE算法跳出局部最优解有重要的影响,针对RWCE算法的步长分布进行研究,通过分析大步长在局部极值跳出中的作用机理,建立了一种全新的步长组合生成方法,并据此提出了一种大步长激励的结构进化策略。最后,通过3个算例验证了结构进化策略的有效性,与文献结果进行对比,结果表明大步长激励的结构进化策略提高了算法的全局搜索能力。展开更多
On the basis of the earthquake （gL I〉3.0） catalog in North China from 1970 to 2009, the pattern of temporal and spatial distribution of medium-small earthquakes in Datong and its surrounding areas is studied by cor...On the basis of the earthquake （gL I〉3.0） catalog in North China from 1970 to 2009, the pattern of temporal and spatial distribution of medium-small earthquakes in Datong and its surrounding areas is studied by correlation analysis with a focus on its anomaly before moderate and strong earthquakes. With different spatial scales, temporal scales and time steps, the spatial distribution of earthquakes is converted to a sequence, then the correlation coefficients between the spatial distribution of medium-small earthquakes in a long-term and a longer time are calculated for the analysis of anomalies before moderate and strong earthquakes. In the study region center on the epicenter of the 1989 Datong- Yanggao earthquake （Ms5. 9） within a radius of less than 0.8~, with the time length of 3600 days, the longer time length of 3700 days, and the time step of 100 days, the correlation coefficient from 1980 to 2009 is steady between 0.94 and 1.00, but there were anomalies with values less than 0. 94 in the 2 years before the 1989 Datong-Yanggao earthquake （Ms 5.9）, the 1991 Datong earthquake （ Ms 5.8） and 1999 Hunyuan earthquake （Ms 5. 6 ）, which indicates the spatial distribution of a medium-small earthquake is very different from steady background seismicity. The implication for earthquake prediction from the anomaly of the correlation coefficient is also discussed with the three conclusions： （1） Before moderate and strong earthquakes in Datong and its surrounding areas, the obvious change of spatial distribution patterns of medium-small earthquake can be a kind of seismic precursor of the 2-year time scale for the prediction of an earthquake＇s time. （2） As the study region is restricted within a radius of less than 0. 8~, the result of correlation analysis is also good for the prediction of an earthquake＇s location. （3） The method of correlation analysis in this paper helps recognize the anomaly of spatial distribution of medium-small earthquake.展开更多
文摘强制进化随机游走算法(random walk algorithm with compulsive evolution,RWCE)具有进化策略简单、控制参数少、全局搜索能力强等特点,是换热网络优化的一种有效方法。鉴于步长对RWCE算法跳出局部最优解有重要的影响,针对RWCE算法的步长分布进行研究,通过分析大步长在局部极值跳出中的作用机理,建立了一种全新的步长组合生成方法,并据此提出了一种大步长激励的结构进化策略。最后,通过3个算例验证了结构进化策略的有效性,与文献结果进行对比,结果表明大步长激励的结构进化策略提高了算法的全局搜索能力。
基金The project was supported by the National Natural Science Foundation of China(Grant Nos.1157119111431006+3 种基金11371202)the Scientific Research Fund of Liaoning Provincial Education Department of China(Grant No.LSNQN201912)the Science and Technology Project of Hebei Science and Technology Department(Grant No.162176489)the Education and Teaching Research Project of Shenyang Agricultural University(Grant No.2018-84)
基金grant from Institute of Crustal Dynamics, China Earthquake Administration (No. ZDJ2011 - 01) and (No. ZDJ2010 - 26)
文摘On the basis of the earthquake （gL I〉3.0） catalog in North China from 1970 to 2009, the pattern of temporal and spatial distribution of medium-small earthquakes in Datong and its surrounding areas is studied by correlation analysis with a focus on its anomaly before moderate and strong earthquakes. With different spatial scales, temporal scales and time steps, the spatial distribution of earthquakes is converted to a sequence, then the correlation coefficients between the spatial distribution of medium-small earthquakes in a long-term and a longer time are calculated for the analysis of anomalies before moderate and strong earthquakes. In the study region center on the epicenter of the 1989 Datong- Yanggao earthquake （Ms5. 9） within a radius of less than 0.8~, with the time length of 3600 days, the longer time length of 3700 days, and the time step of 100 days, the correlation coefficient from 1980 to 2009 is steady between 0.94 and 1.00, but there were anomalies with values less than 0. 94 in the 2 years before the 1989 Datong-Yanggao earthquake （Ms 5.9）, the 1991 Datong earthquake （ Ms 5.8） and 1999 Hunyuan earthquake （Ms 5. 6 ）, which indicates the spatial distribution of a medium-small earthquake is very different from steady background seismicity. The implication for earthquake prediction from the anomaly of the correlation coefficient is also discussed with the three conclusions： （1） Before moderate and strong earthquakes in Datong and its surrounding areas, the obvious change of spatial distribution patterns of medium-small earthquake can be a kind of seismic precursor of the 2-year time scale for the prediction of an earthquake＇s time. （2） As the study region is restricted within a radius of less than 0. 8~, the result of correlation analysis is also good for the prediction of an earthquake＇s location. （3） The method of correlation analysis in this paper helps recognize the anomaly of spatial distribution of medium-small earthquake.
