• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.160-166
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• 2016

Crew fatigue has been recognized as a major cause of maritime accidents. Systematic study on crew fatigue has a direct impact on the human factor, but the various measures being taken to prevent human error account for most of the causes of marine accidents situation are still insufficient. In this study, 128 people who have a variety of career and job types boarded the T/S Hanbada were analyzed the changes of fatigue during the 87-days a Maritime Silk Road Sailing Expedition. Crew fatigue was measured by period of time onboard classified as mental, physiological and physical changes through survey responses and individual interviews of nurses. Also, it was identified the fatigue factor through quantitative statistical analysis. As a result of repeated measures analysis of variance for the changes of fatigue in position and gender criteria in accordance with boarded period, the position-specific analysis was that Professor Rating group has appeared to feel more mental and physical fatigue than the student population. Also, the results of fatigability about the sex-specific analysis have been found that women feel more physical fatigue than men.

• Korean Security Journal
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• no.62
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• pp.205-221
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• 2020

The purpose of this study was to examine the effects of emotional labor on fatigue in regular private participation of sports workers, and to provide basic data to improve the welfare and working environment of private security guards, the core of private security industry. The survey response of 260 private security guards was used as the final analysis data, and the following conclusions were drawn through statistical tests of factor analysis, t-test, correlation analysis, and multiple regression analysis using the SPSS Windows 18.0 statistical program. First, the private security guards who regularly participate in sports showed lower sub-variability of fatigue, physical, exhaustion, and nervous system fatigue than private security guards who did not participate in sports. Second, it was found that fatigue was lower as the inner variables became higher, and that as the surface behavior became higher, the fatigue factor was lower. In conclusion, regular exercise participation can reduce emotional labor and improve fatigue of civil security personnel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5413-5421
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• 2015

The aim of this study was to identify the influences of sleep quality, depression and fatigue on job stress of geriatric hospital workers. The subjects were 175 workers from 6 geriatric hospitals. Data were collected on March, 2015 using a structured questionnaire. The data were analyzed by using SPSS/WIN 21.0 program. The job stress was negatively correlated with sleep quality(r=-.364, p<.001), positively correlated with depression(r=.376, p<.001) and fatigue(r=.646, p<.001). The multiple regression analysis revealed that the most powerful predictor of job stress was fatigue(${\beta}=.581$, p<.001). These results indicate that fatigue affect job stress of the geriatric hospital workers. Therefore, it is necessary to prepare tailored fatigue management program and working conditions that can reduce job stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2465-2471
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• 2012

For the steel structures those are used in harsh sea environments, corrosion fatigue is a challenging issue in connection with design life. In this research, in order to investigate the influence of cathodic overprotection on the corrosion fatigue crack propagation behavior, corrosion fatigue crack propagation test under the condition of -950mV vs SCE was conducted by using of high tensile TMCP steel plate and the relationships between da/dN-${\Delta}K$ were obtained. At this test, when ${\Delta}K$ is low, the crack propagation rates were accelerated compared to those of seawater condition, however, when ${\Delta}K$ is high, the crack propagation rates were lower than those of seawater condition. As the cause for the acceleration and deceleration of corrosion fatigue crack propagation rates under the condition of cathodic overprotection, the role of hydrogen and calcareous deposits are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.599-606
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• 2022

Strain gauges and the bridge weigh-in-motion (BWIM) method are the representative field measurement methods used for fatigue evaluationsof a steel bridge-in-service. For a fatigue reliability evaluation to assess fatigue damage accumulation, the effective stress range and the number of stress cycles applied as the fatigue details can be estimated based on the AASHTO Manual for Bridge Evaluations with the field measurement data of the target bridge. However, the procedure for estimating the effective stress range and the stress cycles from field measurement data has not been explicitly presented. Furthermore, studies that quantitatively compare differences in fatigue evaluation results according to the field measurement data type or processing method used are still insufficient. Here, a fatigue reliability evaluation is conducted using strain and BWIM data that are measured simultaneously. A frame model and a shell-solid model were generated to examine the effect of the accuracy of the structural analysis model when using BWIM data. Also, two methods of handling BWIM data when estimating the effective stress range and average daily cycles are defined. As a result, differences in evaluation results according to the type of field measurement data used, the accuracy of the structural analysis model, and the data handling method could be quantitatively confirmed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2063-2068
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• 2013

Ship and offshore structures, those are to be used under the seawater conditions are prone to corrosion. In this research, the effect of rust existence on the fatigue strength at structural member of ship and offshore structure was investigated. For this purpose, fatigue tests for the rust removed specimen were conducted. In addition, the comparison of fatigue strength between rust removed specimen and rusted specimen was conducted. With these test results, fatigue strength share effect was investigated. Finally, at this research, it was found that there is fatigue strength share effect on the rust. In comparison of fatigue strength reduction factor, fatigue strength of the rust removed specimen is 18.1% lower than that of the rusted specimen. From the above, it was known that as far as there are not any harmful ingredients in it, rust on the steel plate is beneficial in an aspect of fatigue strength.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.559-569
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• 2020

This study was conducted to examine relationships among job environment, psychological work demand, fatigue, musculoskeletal symptoms, then to investigate the factors influencing musculoskeletal symptoms of care workers in long-term care hospitals. A total of 128 care workers recruited from three long-term care hospitals in S city. Self-reported questionnaire survey was conducted from April to May, 2020. The results were as follows: The musculoskeletal symptoms of the care workers were the sum of the frequency of symptom occurrence, duration of symptoms, and intensity of pain in the three parts of the shoulder, hand/wrist/finger, and waist. The average score was 11.41±9.50 points out of 42. According to the hierarchical regression analysis, their musculoskeletal symptoms were significantly influenced by working department(β=.18, p=.034), psychological work demand(β=.21, p=.013) and fatigue(β=.25, p=.003), explained 21.6% of the total variance(F=6.87, p<.001). Based on our results, in order to reduce musculoskeletal symptoms of care workers in nursing hospitals, it is necessary to develop and apply an intervention program that can reduce psychological work demand and fatigue in consideration of the severity of the patient in charge.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.201-207
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• 2010

Recently, about 600 cases of marine accidents occur annually in Korea. According to many studies and analyses on occurrence of marine accidents, 70~80% of marine accidents were caused by human factors. Among the human factors, navigation officers' fatigue is very important factor. Although navigation officers' fatigue serves as an important role in marine accidents, there is no method to exactly examine the degree of officers' fatigue. Accordingly, this study analyzed human factors according to types of marine accidents and extracted important five factors affecting navigation officers' fatigue through the questionnaire survey by means of literatures and 5-point scale. In addition, evaluation factors of marine accident risks caused by fatigue factors were divided and structured by using ISM. Lastly, it found out the importance of each fatigue factor drawn by AHP and decided marine accidents that were most highly caused by navigation officers' fatigue in order. At the result, weights were high as sleep time 0.385, stress 0.302, health condition 0.139, rest time 0.099, alcohol and drug 0.074 in fatigue factors, and death and injury 0.328, collision 0.308, grounding 0.195, sinking 0.094, fire accident 0.075 in evaluation factors of marine accident risks. Therefore, the control plan to lower marine accident risks should be prepared on the basis of high weight factors.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.643-653
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• 2020

This study is a descriptive research study to identify the relationship between cancer fatigue, quality of sleep, environmental sleep disturbance, and comfort perceived by hospitalized cancer patients. Data were collected with structured questionnaires from 113 cancer patients from a university hospital in J city, Gyengnam, from September 17 to November 5, 2019, and analyzed using SPSS 21.0, using independent t-test, one-way ANOVA, Scheffé test, Pearson's correlation coefficient, and stepwise multiple regression. The subjects' Comfort is significantly different depending on education level, Cancerous type, Radiation treatment status, Usual exercise status. The result showed that comfort was negatively correlated with cancer fatigue(r=-.609, p<.001), quality of sleep(r=-.478, p<.001), and environmental sleep disturbance(r=-.297, p=.001). The variables that had a significant effect on comfort were cancer fatigue(β=-.42, p<.001), subjective quality of sleep(β=-.30, p=.001), and cancer type(β=-.18, p<.015), and the explanatory power was 46.1%(F=27.24, p<.001). Based on these results, it is necessary to develop a program to improve the quality of sleep and to reduce the cancer fatigue by cooperating with medical and nursing staff in multidisciplinary ways to enhance the comfort of hospitalized cancer patients.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.224-225
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• 2021

해양사고의 주요 원인으로 언급되고 있는 피로요인은 장시간 소요되는 선박의 운항과정에서 발생할 수 있는 사고발생의 주된 요인이다. 이러한 피로의 유발 요인 중 하나인 음주운항으로, 이로 인한 해양사고는 대형 인명피해 뿐만 아니라 해양환경오염이라는 국가적 대재난으로 이어질 수 있다. 다행히 「해사안전법」 시행령 개정에 따라 주취운항 단속 기준 (혈중알콜농도 기준)이 기존 0.08%에서 2011년 0.05%, 2014년 0.03%로 강화됨에 따라 주취 운항의 위험성에 대한 인식은 개선되고 있으나, 최근 5년 동안 선박 음주 운항 단속 건수는 총 556건으로 나타났으며, 음주운항으로 인한 충돌, 좌초 등의 사고가 지속적으로 발생하고 있다. 본 발표에서는 음주운항이 선박운항에 미치는 영향을 알아보기 위해 선박운항 시뮬레이터 데이터 분석을 통한 음주운항 패턴 분석 결과를 소개하고자 한다.