A statistical analysis on earthquake activity in the Kashi-Wuqia intersection area triggered by earth tide is done by Schusters test and the Permutation test on daily and monthly scales. The north-south,east-west comp...A statistical analysis on earthquake activity in the Kashi-Wuqia intersection area triggered by earth tide is done by Schusters test and the Permutation test on daily and monthly scales. The north-south,east-west component of the tidal force and tidal body stress are chosen as the tidal curve in the daily scale. The results show that most of the earthquakes occurred near the maximum 0° of the three kinds of tidal curves,the predominant tidal phases of the earthquake are- 5. 86°,6. 60° and- 15. 52°,and the frequency of the earthquakes increases with the increase of the tide; with three kinds of tidal curves( the north-south,east-west component of the tidal force and tidal body stress),the p S of Schusters test for all the earthquakes is 10. 52%,2. 40% and 2. 06%,and the p P of the Permutation test is 10. 90%,2. 40% and 2. 06%,and the results of p S and p P based on the east-west component of the tidal force and tidal body stress are below the threshold of 0. 05 that tidal triggering of earthquakes. In the monthly scale,both the p S and p P are very low( close to 0),far below the threshold of 0. 05 of tidal triggering of earthquakes,and the predominant tidal phase for earthquake triggering is- 18. 95°,close to the maximum 0°( new moon and full moon) of the earth tide in monthly scale. Regarding the statistical test result of tidal triggering of earthquakes,a preliminary explanation is given as to why the trigger effect in the east-west direction is greater than that in north-south direction.展开更多
Group navigation is of great importance for many animals, such as migrating flocks of birds or shoals of fish. One theory states that group membership can improve navigational accuracy compared to limited or less accu...Group navigation is of great importance for many animals, such as migrating flocks of birds or shoals of fish. One theory states that group membership can improve navigational accuracy compared to limited or less accurate individual naviga- tional ability in groups without leaders （＂Many-wrongs principle＂）. Here, we simulate leaderless group navigation that includes social connections as preferential interactions between individuals. Our results suggest that underlying social networks can reduce navigational errors of groups and increase group cohesion. We use network summary statistics, in particular network motifs, to study which characteristics of networks lead to these improvements. It is networks in which preferences between individuals are not clustered, but spread evenly across the group that are advantageous in group navigation by effectively enhancing long-distance information exchange within groups. We suggest that our work predicts a base-line for the type of social structure we might expect to find in group-living animals that navigate without leaders展开更多
基金sponsored by the Earthquake Situation Tracking Task of 2013(2013020119)the Fund of Earthquake Administration of Xinjiang Uygur Autonomous Region,China(201304)
文摘A statistical analysis on earthquake activity in the Kashi-Wuqia intersection area triggered by earth tide is done by Schusters test and the Permutation test on daily and monthly scales. The north-south,east-west component of the tidal force and tidal body stress are chosen as the tidal curve in the daily scale. The results show that most of the earthquakes occurred near the maximum 0° of the three kinds of tidal curves,the predominant tidal phases of the earthquake are- 5. 86°,6. 60° and- 15. 52°,and the frequency of the earthquakes increases with the increase of the tide; with three kinds of tidal curves( the north-south,east-west component of the tidal force and tidal body stress),the p S of Schusters test for all the earthquakes is 10. 52%,2. 40% and 2. 06%,and the p P of the Permutation test is 10. 90%,2. 40% and 2. 06%,and the results of p S and p P based on the east-west component of the tidal force and tidal body stress are below the threshold of 0. 05 that tidal triggering of earthquakes. In the monthly scale,both the p S and p P are very low( close to 0),far below the threshold of 0. 05 of tidal triggering of earthquakes,and the predominant tidal phase for earthquake triggering is- 18. 95°,close to the maximum 0°( new moon and full moon) of the earth tide in monthly scale. Regarding the statistical test result of tidal triggering of earthquakes,a preliminary explanation is given as to why the trigger effect in the east-west direction is greater than that in north-south direction.
文摘Group navigation is of great importance for many animals, such as migrating flocks of birds or shoals of fish. One theory states that group membership can improve navigational accuracy compared to limited or less accurate individual naviga- tional ability in groups without leaders （＂Many-wrongs principle＂）. Here, we simulate leaderless group navigation that includes social connections as preferential interactions between individuals. Our results suggest that underlying social networks can reduce navigational errors of groups and increase group cohesion. We use network summary statistics, in particular network motifs, to study which characteristics of networks lead to these improvements. It is networks in which preferences between individuals are not clustered, but spread evenly across the group that are advantageous in group navigation by effectively enhancing long-distance information exchange within groups. We suggest that our work predicts a base-line for the type of social structure we might expect to find in group-living animals that navigate without leaders
