표제지
초록
Abstract
목차
기호 설명 13
1장 서론 14
1.1. 연구 배경 14
1.2. 연구 대상 16
2장 이론 연구 18
2.1. 이상탐지 방법론 18
2.2. 기계학습 기반 이상탐지 기법 19
2.2.1. Isolation Forest(IF) 19
2.2.2. Local Outlier Factor(LOF) 20
2.2.3. One-Class SVM (OC SVM) 20
2.2.4. Principal Component Analysis(PCA) 21
2.2.5. LSTM Auto Encoder(LSTM-AE) 22
3장 공기건조기 이상탐지 방안 23
3.1. 공기건조기 구조 및 고장원인 분석 23
3.2. 수집 데이터 현황 23
3.3. 작동 on 데이터 셋 분리 26
3.4. 정상데이터 셋 확보 27
3.5. 변수 선정 (Feature selection) 28
3.6. 학습/테스트 데이터 셋 확보 30
3.7. 알고리듬별 모델 구축 31
3.8. 이상스코어 임계치(Threshold) 선정 32
3.9. 이상 연속발생횟수(frequency) 기준 정의 33
4장 연구결과 34
4.1. 알고리듬별 성능 검증 34
4.1.1. 건조통 고장 35
4.1.2. 캠모터 고장 36
4.1.3. 히터 off 37
4.1.4. 알고리듬 검증 결과 39
4.2. 부대별 최종 모델 확보 39
5장 결론 44
참고문헌 46
Table 1. Algorithm parameter 32
Table 2. Performance score of algorithms 39
Table 3. Performance of best model on each army unit 41
Table 4. Performance of best model on each army unit 43
Figure 1. Supervised Learning 15
Figure 2. Unsupervised Learning 15
Figure 3. K-SAM 16
Figure 4. Structure of Air Dryer 24
Figure 5. Data Pattern 24
Figure 6. Dry On Pattern 25
Figure 7. Inner temperature/Inner humidity(example) 25
Figure 8. Inner humidity pattern on dryer on 26
Figure 9. Degree of inner humidity 26
Figure 10. Changing dryer unit on operation 27
Figure 11. Short cycle of on/off operation 27
Figure 12. Hunting 28
Figure 13. Data cleansing by inner temperature change rate 28
Figure 14. Pearson correlation (ooo army unit) 29
Figure 15. Failure of dryer unit 30
Figure 16. Failure of cam motor 31
Figure 17. Heater off 31
Figure 18. Best threshold by using bootstrap method 33
Figure 19. Effect of setting the continuous frequency 33
Figure 20. Example of good performance model 34
Figure 21. Test result of failure of dryer unit for A unit & B unit 35
Figure 22. Test result of failure of dryer unit for C unit & D unit 35
Figure 23. Test result of failure of dryer unit for E unit & F unit 36
Figure 24. Test result of failure of cam motor for A unit & B unit 36
Figure 25. Test result of failure of cam motor for C unit & D unit 37
Figure 26. Test result of failure of cam motor for E unit & F unit 37
Figure 27. Test result of failure of heater off for A unit & B unit 38
Figure 28. Test result of failure of heater off for C unit & D unit 38
Figure 29. Test result of failure of heater off for E unit & F unit 38
Figure 30. Performance of final model for A unit & B unit 40
Figure 31. Performance of final model for C unit & D unit 42
Figure 32. Performance of final model for E unit & F unit 42