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本文用模式识别方法(CORA—3修改方法)研究了云南及其邻近地区大地震的发生时间与中强地震活动特性的关系。结果表明(不分子集):M≥7.0级大震前1—2年内,5—5.9级地震频度有明显增强。前1年6—6.9级地震相对减弱,前2—4年内6—6.9级地震可增至一定水平。对于CORA—3修改算法在采用“CLUSTERS”算法和不用“CLUSTERS”算法所得识别分类结果基本一致。FH(future history test)试验表明,用1930—1986年为学习时段,1969—1986年为预测时段。得到D类识别率为0.6,N类误识率为0.38。
This paper studies the relationship between the occurrence time of large earthquakes in Yunnan and its adjacent areas and the characteristics of moderate-strong earthquakes by using pattern recognition method (CORA-3 modified method). The results show that: (no molecular subset): M≥7.0 large earthquakes 1-2 years ago, the magnitude of 5-5.9 earthquakes significantly increased. The magnitude 6-6.9 earthquakes in the previous year were relatively weakened, and the earthquakes of magnitude 6-6.9 in the preceding 2-4 years could be increased to a certain level. For the CORA-3 modification algorithm, the CLUSTERS algorithm is basically the same as the CLUSTERS algorithm. FH (future history test) tests show that the period of 1930-1986 is the learning period, and the period of 1969-1986 is the forecasting period. The recognition rate of D class is 0.6 and N class error rate is 0.38.