1、estimated energy average period from spectral density distribution
2、Mean time to failure is the average continuously operational period — i.e. the average period between the end of one failure and the beginning of the next.
3、The average class hours of periodontal theory are 26.8 ( 12 - 53 ), and the average class hours of lab training are 29.6 ( 12 - 49 ), the average period clinical training is 4 - 8 weeks.
