The Influence of Fatigue, Recovery, and Environmental Factors on the Body Stability of Construction Workers : 피로, 회복 및 환경 요인이 건설 노동자의 신체 안정성에 미치는 영향

다국어 초록 (Multilingual Abstract)

The Influence of Fatigue, Recovery, and Environmental Factors on the Body Stability of Construction Workers A case study of masonry work JO DAEHWI Construction Engineering and Management/Materials Major Department of Architectural Engineering Graduate School, Dankook University Advisor：Professor Kim Hyunsoo In the construction industry, falls, slips, and trips (FST) account for 42.3% of all accidents. The primary cause of FST incidents is directly related to the deterioration of workers’ body stability. To prevent FST-related accidents, it is crucial to understand the interaction between physical fatigue and body stability in construction workers. Therefore, this study investigates the impact of fatigue on body stability in various construction site environments using Dynamic Time Warping (DTW) analysis. We conducted experiments reflecting six different fatigue levels and four environmental conditions. The analysis process involves comparing changes in DTW values derived from acceleration data obtained through wearable sensors across varying fatigue levels and construction environments. The results reveal the following changes in DTW values across different environments and fatigue levels: for non-obstacle, obstacle, water, and oil conditions, DTW values tend to increase as fatigue levels rise. In our experiments, we observed a significant decrease in body stability against external environments starting from fatigue Levels 3 or 4 (30% and 40% of the maxi-mum failure point). In the non-obstacle condition, the DTW values were 9.4 at Level 0, 12.8 at Level 3, and 23.1 at Level 5. In contrast, for the oil condition, which exhibited the highest DTW values, the values were 10.5 at Level 0, 19.1 at Level 3, and 34.5 at Level 5. These experimental results confirm that the body stability of construction workers is influenced by both fatigue levels and external environmental conditions. Further analysis of recovery time, defined as the time it takes for body stability to return to its original level, revealed an increasing trend in recovery time as fatigue levels increased. This study quantitatively demonstrates through wearable sensor data that, as fatigue levels increase, workers experience decreased body stability and longer recovery times. The findings of this study can inform individual worker fatigue management in the future. Keywords: FSTs (falls; slips; and trips); fatigue; body stability; Inertial Measurement Unit (IMU); Dynamic Time Warping (DTW)

목차 (Table of Contents)

• Abstract ⅰ
• Contents iii
• List of Tables v
• List of Figures vi
• Ⅰ. Introduction 1
• 1.1 Introduction 1
• 1.2 literature review 3
• Ⅱ. Methodology 7
• 2.1 Methodology 7
• 2.2 Experimental design 10
• 2.3 Body Stability Analysis Using the DTW Algorithm 17
• 2.4 Body Stability Recovery Based on Fatigue Levels 20
• Ⅲ. Results 22
• 3.1 Investigation of Body Stability Changes Due to Fatigue in Various Construction Environments Using DTW Analysis 25
• 3.2 Results of Body Stability Recovery Analysis for Six Fatigue Levels 26
• 3.3 Comparative Analysis of Fatigue Levels and Working Environment Conditions on Overall Worker Stability and Recovery Time 29
• Ⅳ. Discussion 31
• 4.1 Changes in Body Stability According to Fatigue Levels and Hazard Types 31
• 4.2 Impact of Fatigue Levels and Hazard Proximity on Worker Body Stability in Construction Environments 35
• 4.3 Contributions and practical applications 38
• 4.4 Limitations 39
• 4.5 Future Research 41
• Ⅴ. Conclusions 42
• 5.1 Conclusion 42
• References 44
• 국문 초록 53
• 감사의 글 55