By increasing the number of testing points and proper arrangement of them,the accuracy of pile defect testing is improved,which is proved by the coring examination method,then the referenced steps of pile defect testing by the low strain reflective wave method is given.

After analyzing how to apply preemption-threshold-scheduling into real-time systems among which the recoveries of safety tasks may be executed at higher priority levels and the sizes of memories are limited,we research realization methods about memory backuprecovery on the Linux platform based on increment checkpoints for no-preemption task groups.

In order to avoid system blocked which is caused by software filter in digital input detection,a new method of digital input detection is designed by the clock tick and flag group in μC /OS-II.