In this study, the mean time to failures of a system under shock models are derived. The system receives shocks according to a stochastic process. The expected system lifetime under homogeneous Poisson shock process, nonhomogeneous Poisson shock process, and a general renewal shock process are derived. Some numerical examples are presented.

Abstract
 1. 서론
 2. 충격모형과 시스템의 평균수명
  2.1 포아송 충격모형
  2.2 비제차 포아송 충격모형
  2.3 재생 충격모형
 3. 결론
 4. 참고문헌

• 유영관
• 박노국