Based on the background of the medium term seismic gap, and the creep rate slow down after accelerated strain release, by using a method of gradually reducing the step length and the window length of scanning, the c...Based on the background of the medium term seismic gap, and the creep rate slow down after accelerated strain release, by using a method of gradually reducing the step length and the window length of scanning, the characteristics and criteria of a short term seismic gap have been studied from multi dimension space research. A new method for identifying a short term gap from 3 D axial stability collation has been advanced. Through the study of 26 earthquake examples in north and south west region of China, we found that a short term seismicity gap appeared in 9~16 months before a strong earthquake, this type of gap is different from the seismogenic gap, and will lasted 4~7 months, end at the time of 3~8 months before the mainshock . The ending is marked by the appearance of a significant earthquake in or near the gap (Sun and Cao, 1995) and of small earthquake in the gap.展开更多
By introducing element equivalence class that proposes dynamic characteristic into Pawlak Z rough sets theory, the first author of this paper improved Pawlak Z rough sets and put forward S-rough sets (singular rough ...By introducing element equivalence class that proposes dynamic characteristic into Pawlak Z rough sets theory, the first author of this paper improved Pawlak Z rough sets and put forward S-rough sets (singular rough sets). S-rough sets are defined by element equivalence class that proposes dynamic characteristic. S-rough sets have dynamic characteristic. By introducing the function equivalence class (law equivalence class) that proposes dynamic characteristic into S-rough sets, the first author improved S-rough sets and put forward function S-rough sets (function singular rough sets). Function S-rough sets have dynamic characteristic and law characteristic, and a function is a law. By using function S-rough sets, this paper presents law identification, law identification theorem, and law identification criterion and applications. Function S-rough sets are a new research direction of rough sets theory, and it is also a new tool to the research of system law identification.展开更多
文摘Based on the background of the medium term seismic gap, and the creep rate slow down after accelerated strain release, by using a method of gradually reducing the step length and the window length of scanning, the characteristics and criteria of a short term seismic gap have been studied from multi dimension space research. A new method for identifying a short term gap from 3 D axial stability collation has been advanced. Through the study of 26 earthquake examples in north and south west region of China, we found that a short term seismicity gap appeared in 9~16 months before a strong earthquake, this type of gap is different from the seismogenic gap, and will lasted 4~7 months, end at the time of 3~8 months before the mainshock . The ending is marked by the appearance of a significant earthquake in or near the gap (Sun and Cao, 1995) and of small earthquake in the gap.
基金the National Natural Science Foundation of China (Grant No. 60364001)the key Project of Chinese Ministry of Education (Grant No. 206089)the Natural Science Foundation of Shandong Province of China (Grant No. Y2007H02)
文摘By introducing element equivalence class that proposes dynamic characteristic into Pawlak Z rough sets theory, the first author of this paper improved Pawlak Z rough sets and put forward S-rough sets (singular rough sets). S-rough sets are defined by element equivalence class that proposes dynamic characteristic. S-rough sets have dynamic characteristic. By introducing the function equivalence class (law equivalence class) that proposes dynamic characteristic into S-rough sets, the first author improved S-rough sets and put forward function S-rough sets (function singular rough sets). Function S-rough sets have dynamic characteristic and law characteristic, and a function is a law. By using function S-rough sets, this paper presents law identification, law identification theorem, and law identification criterion and applications. Function S-rough sets are a new research direction of rough sets theory, and it is also a new tool to the research of system law identification.