• 한국안전학회지
• /
• 제27권3호
• /
• pp.125-130
• /
• 2012

According to the Korea National Statistical Office data in 2010, the population over ages of 65 years would possess to 11.3% whole population of Korea in 2011 denoting Korea is already in the aging society. Old age is associated with inevitable time-dependent losses in physical capabilities. However the maintenance of physical capabilities is essential for continuing independence in old age. The work ability index(WAI) was constructed to reveal how well a worker is able to perform his work. This study focused on the discovery of an industrial and age-related influences on the work ability and job stress of workers in the shipbuilding, house managing, apartment construction industry. For this, the study conducted a job stress test using the Korean Occupational Stress Questionnaire Short Form, and employee performance evaluations using the Work Ability Index (WAI) of the Finnish Institute of Occupational Health (FIOH) on 3,228 workers in the shipbuilding, house managing and apartment construction industry. SPSS 12.0 K statistics program was used for statistics analysis and significance was verified with the Kruskal-Wallis test, a corporate body of nonparametric statistical analysis. As a result, employee performance had significant differences, depending on age, an industrial and years of service. The mean WAI score of the shipbuilding industry was lower than that of the other industry. Additionally, it was found that employee work ability decreased more as job stress increased.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2018년도 춘계학술대회
• /
• pp.36-37
• /
• 2018

이 연구는 선내시스템 원격모니터링 서비스 중 하나인 화재안전모듈에서 화재안전지수에 따른 대응가이던스 개발에 대한 연구로, 서비스 선박 중 하나인 여객선을 대상으로 화재센서 위치에 따른 구역을 식별하고, 구역에 따른 대응가이던스 개발에 대한 연구를 수행하였다.

• 한국안전학회지
• /
• 제38권6호
• /
• pp.1-8
• /
• 2023

The health state of the oil transformer is evaluated by the age of use and the state of internal defects. Mineral Oil, used as an insulator for oil transformers, creates specific gases and compounds through chemical reactions caused by heat, moisture, and partial discharge inside the transformer. It is possible to determine the aging and defect of the transformer through these gases and compounds. So, it is an important indicator to evaluate the health of a transformer. In this study, factors for assessing the health of transformers were hierarchically categorized, and key factors for each hierarchy were selected for design weighting. These weights were determined through surveys conducted with experts in the fields of transformer design, operation, and quality. For the health of a transformer, defect-related factors are approximately three times more important than factors related to aging. Additionally, defect-related factors showed a higher weighting for gases generated at high temperatures. Furthermore, Furan was determined to have a high weight, directly associated with insulating paper aging. Based on these findings, a health index was proposed, and a comparative analysis was conducted by categorizing 40 operational transformers into normal and comparison groups to evaluate and validate it.

• 교통기술과정책
• /
• 제10권6호
• /
• pp.42-51
• /
• 2013

• 한국구조물진단유지관리공학회 논문집
• /
• 제23권6호
• /
• pp.70-76
• /
• 2019

본 논문은, 시설물안전법의 적용을 받지 않아 안전사각 지대에 놓여 있는 중소규모 교량들의 유지관리 전략 수립시 기초자료로 활용할 수 있는, 중소규모 교량 성능평가 우선순위 결정 방안을 제시하기 위해 실시하였다. 이를 위해 취약도와 영향도를 기반으로 하는 위험도 지수를 산출하고, 산출된 위험도 지수에 따라 이들 교량들을 성능평가 즉시실시교량, 단기실시교량 및 관찰교량으로 구분하여 제안하고, 실제 공용중에 있는 중소규모 교량에 적용하여 제안한 방안의 현장 적용성을 확인하였다. 연구결과, 여기서 제시된 방안은 향후 중소규모 교량의 유지관리 전략 수립에 적절히 활용되어 중소규모교량 사고 방지 및 유지관리 예산절감에 기여할 수 있을 것으로 판단되었다.

• Earthquakes and Structures
• /
• 제18권1호
• /
• pp.73-82
• /
• 2020

With the coal mining depth increasing, both stress and gas pressure rapidly enhance, causing coal and gas outburst risk to become more complex and severe. The conventional method for prediction of coal and gas outburst adopts one prediction index and corresponding critical value to forecast and cannot reflect all the factors impacting coal and gas outburst, thus it is characteristic of false and missing forecasts and poor accuracy. For the reason, based on analyses of both the prediction indicators and the factors impacting coal and gas outburst at the test site, this work carefully selected 6 prediction indicators such as the index of gas desorption from drill cuttings Δh₂, the amount of drill cuttings S, gas content W, the gas initial diffusion velocity index ΔP, the intensity of electromagnetic radiation E and its number of pulse N, constructed the Bayes discriminant analysis (BDA) index system, studied the BDA-based multi-index comprehensive model for forecast of coal and gas outburst risk, and used the established discriminant model to conduct coal and gas outburst prediction. Results showed that the BDA - based multi-index comprehensive model for prediction of coal and gas outburst has an 100% of prediction accuracy, without wrong and omitted predictions, can also accurately forecast the outburst risk even for the low indicators outburst. The prediction method set up by this study has a broad application prospect in the prediction of coal and gas outburst risk.

• 한국환경과학회지
• /
• 제28권12호
• /
• pp.1133-1145
• /
• 2019

Successful launch requires state-of-the-art launch vehicle technology and constant test operations, However, the meteorological threat to the launch vehicle flight trajectory is also an important factor for launch success. Atmospheric stability above the Naro Space Center at the this time is very important, especially because the initial flight operation can determine the success of the launch. Moreover, during the flight of launch vehicle with rapid pressure and thrust into the atmosphere, convection activity in the atmosphere may create environmental conditions that cause severe weather threats such as thunderstorms. Hence, studies of atmospheric instability characteristics over the Naro Space Center are a necessary part of successful launch missions. Therefore, the main aims of this study were to (1) verify the atmospheric stability index and convection activity characteristics over the Naro Space Center using radiosonde data observed from 2007 to 2018 by the Naro Space Center, (2) analyze changes in the atmospheric stability index according to monthly and seasonal changes, and (3) assess how the calculated atmospheric stability index is related to actual thunderstorm occurrence using statistical analysis. Additionally, we aimed to investigate the atmospheric characteristics above the Naro Space Center through the distribution chart of the atmospheric stability index during summer, when convection activity is highest. Finally, we assessed the relationship between lightning occurrence and unstable atmospheric conditions, through predictability analysis performed using the lightning observation data of the Korea Meteorological Administration.

• 대한안전경영과학회지
• /
• 제17권2호
• /
• pp.55-66
• /
• 2015

In the perspective of industrial health management, it is important for the employee to decrease their job stress, to improve their productivity and quality of labor. In this study, the job stress, and it's influence on PWI(Psychosocial Wellbeing Index) were investigated by the questionnaire survey of 138 industrial workers who had studied assistive technology in college. The contents of questionnaire consist of the demographic characteristics, job-related characteristics, job stress and psycho-social stress. We evaluated job stress by KOSS-SF(Korean Occupational Stress Scale-Sort Form) and psychosocial stress by PWI-SF(Psychosocial Well-being Index-Short Form). To analyze the results, we evaluated the exposure level of KOSS and PWI by demographic characteristics and job-related characteristics using significance tests. Also, we estimated the relationship among demographic characteristics, job-related characteristics, job stress and psychosocial stress, using correlation analysis. As a results, all workers were found to be in a group under the high risky stress. It showed that the scale index of female's job non-autonomy and pwi were much larger than those of male's. Therefore, to guarantee job autonomy of female workers should be more emphasized, to improve their working environment. Job type had significant relationships with many job stress category; physical environment, job demand, job instability and organization culture. Regarding pwi, the scale index of the workers who is in charge of the civil service such as contacting the disabled and the aged in person, were much larger than that of the other workers. Accordingly, the job stress management program including physical environment, job demand, job instability and organization culture, should be suggested, to decrease the stress of the workers in charge of the disabled and the elders service. The strongest predictors of pwi was organization system through maximum positive relations between organization system and pwi. Therefore, it indicates that improvement of organization system such as a fair merit rating, a manpower supply, demand plan and department cooperation is urgently needed to reduce pwi.

• 해양환경안전학회지
• /
• 제24권7호
• /
• pp.907-915
• /
• 2018

다양한 산업분야에서 중금속의 사용이 증가할수록, 중금속으로 인한 환경오염과 생물학적 위해성에 대한 우려의 목소리가 커지고 있다. 통계 지수는 배경농도 값과의 비교를 통해 중금속 오염농도를 정규화 시킴으로써 토양 오염의 정도를 수치화하고, 단계 별로 오염 정도를 판단 할 수 있어 많이 사용된다. 본 연구에서는 농축인자(Enrichment factor, EF), 축적 계수(accumulation index), 잠재적 생물학적 위험 지표(potential ecological risk index)등을 이용하여 중공업 근처 토양 내 중금속 오염가능성을 평가하였다. 연구결과, 중금속의 오염 정도는 정부 가이드라인에 비하여 낮은 수준이었으나, 특정 위치에서 아연, 구리, 납 등의 중금속 오염이 관찰 되었다. 농축인자, 축적계수, 생물학적 위험 지표를 통해 일부 토양 내 중금속 오염이 우려할 수준이며, 주변에 존재하는 인위적 오염원에 의한 오염가능성이 있음을 확인하였다. 연구대상지의 추가 시료채취 및 추정되는 오염원의 시료 확보 후, 동위원소 분석 및 x-ray 기반 분석을 통해 오염원 추적연구가 필요할 것으로 판단된다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제44권6호
• /
• pp.599-605
• /
• 2021

The International Electrotechnical Commission (IEC) 62494-1 has defined the exposure index (EI) that have a proportional relationship with the dose incident on the image receptor, and target exposure index (EI_T), deviation index (DI). In this study, an appropriate EI_T for skull radiography was established through the diagnostic reference level (DRL) and changes in DI were confirmed. Entrance surface dose (ESD) and EI were obtained using the computed radiography system displayed the EI as per IEC on console and skull phantom by experiment based on the national average exposure conditions announced in 2012 and 2019. And appropriate EI_T was established by applying the DRL in 2012 and 2019. As a results, the EI_T is changed according to the change in the DRL, and the exposure condition that becomes the ideal DI according to the change in the EI_T also has a difference of about 1.41 times. DRL is recommended to optimize the patient dose, however it is difficult to measure in real time at medical institutions whereas EI and DI are displayed on the console at the same time as exposure. When the EI_T is set based on the DRL and the DI is closed to an ideal value, it is useful as a patient dose management tool. Therefore, when the EI_T is periodically managed along with the revision of the DRLs, the patient dose can be optimized through the EI, EI_T and DI.