• Safety and Health at Work
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• v.9 no.2
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• pp.159-163
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• 2018

Background: Fatigue and sleepiness are inter-related and common among road transport drivers. In this study, sleep deprivation and fatigue among chemical transportation drivers were examined. Methods: A cross-sectional study surveying 107 drivers from three hazardous types of chemical production and transportation industries (nonflammable gases, flammable gases, and flammable liquids) was conducted. Data on sleep deprivation were collected using questionnaires of the Stanford Sleeping Scale and the Groningen Sleep Quality Scale. Fatigue was assessed using an interview questionnaire and a flicker fusion instrument. Results: Chemical drivers had a mean sleeping scale (Stanford Sleeping Scale) of 1.98 (standard deviation 1.00) and had a mean score of 1.89 (standard deviation 2.06) on the Groningen Sleep Quality Scale. High-risk drivers had higher scores in both the Stanford Sleeping Scale and the Groningen Sleep Quality Scale with a mean score of 2.59 and 4.62, respectively, and those differences reached statistical significance (p < 0.05). The prevalence of fatigue, as assessed through a critical flicker fusion analyzer, subjective fatigue question, and either of the instruments, was 32.32%, 16.16%, and 43.43%, respectively. Drivers who slept <7 hours and had poor sleep quality were found to have more fatigue than those who slept enough and well. Drivers who had a more sleepiness score resulted in significantly more objective fatigue than those who had a less sleepiness score. Conclusion: Sleep quality and sleeping hour can affect a driver's fatigue. Optimization of work-rest model should be considered to improve productivity, driver retention, and road safety.

• Journal of the Korean Dietetic Association
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• v.9 no.4
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• pp.326-335
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• 2003

This study was carried out to collect information to establish a framework for meal management and nutritional service for prevention of chronic degenerative disease in the industrial workers. We investigated the health concerned life-style, nutrient intakes, anthropometry and biochemical parameters in the male workers in Korea by work condition. Anthropometric parameters of height, weight, waist, hip and triceps skinfold thickness were measured and biochemical parameters including Urine pH, hemoglobin, blood glucose, total cholesterol, GOT, GPT, $\gamma$-GPT and blood pressure were determined for 101 subjects(50 office workers : 33.9yr, 51 laborers : 34.4yr). To assess the nutrient intakes and diet quality of workers, dietary intake was measured by one day 24-hour recall method. Result of anthropometric parameters of height(p<0.01), weight(p<0.05), hip(p<0.05), TSF(p<0.01) were significantly higher in office workers than in laborers. Biochemical parameters were not significantly difference in both of them. Average daily nutrient intakes of both groups was higher than the Korean RDA and report on 2001 National Health & Nutrition Survey. The calcium(p<0.01), iron(p<0.05), vitamin A(p<0.01), vitamin B1(p<0.01) and niacin(p<0.05) intakes in laborers were significantly higher than in office workers. Nutrition adequacy ratio(NAR), mean adequacy ratio(MAR) and index of nutritional quality(INQ) of laborers were higher than those of office workers. This results indicated that the onset possibility of chronic degenerative disease appeared higher in office workers. Therefore, meal menagement and nutritional service for prevention of chronic degenerative disease of industrial works needs to be more variant guidelines.

• Journal of the Korea Society for Simulation
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• v.30 no.4
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• pp.1-8
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• 2021

Deep learning is one of the most widely accepted methods for the forecasting of time series data which have the complexity and non-linear behavior. In this paper, we investigate the modification of a state-of-art WaveNet deep learning architecture and walk forward validation (WFV) in order to forecast electric power consumption data 24-hour-ahead. WaveNet originally designed for raw audio uses 1D dilated causal convolution for long-term information. First of all, we propose a modified version of WaveNet which activates real numbers instead of coded integers. Second, this paper provides with the training process with tuning of major hyper-parameters (i.e., input length, batch size, number of WaveNet blocks, dilation rates, and learning rate scheduler). Finally, performance evaluation results show that the prediction methodology based on WFV performs better than on the traditional holdout validation.

• Korean Journal of Biological Psychiatry
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• v.29 no.2
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• pp.46-55
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• 2022

Objectives Many studies have reported noticeable increases in the proportion of employees working either relatively short or relatively long hours. Such trends have been accompanied by an increasing concern that how much subjective mental well-being of employees would be influenced by their hours of work. The aim of this study was to investigate the association between work hours and clinically relevant depressive symptoms with demographic variables adjusted. Methods Participants were employees of a total of 56 private companies and local government organizations in Korea, aged 19 to 65 years. A self-report questionnaire that included items on working hour, job stress, levels of depression, and socio-demographic factors was administered to 15360 Korean employees, with 14477 valid responses. Hierarchical linear regression analyses, adjusted for sociodemographic factors, job related demographic factors, job stress, were used additionally to estimate the association between working hours and depressive scores. Results We found that working more than 40 hours per week correlated positively with the level of depressive symptoms after adjusting for demographic variables and the level of job stress. Furthermore, working 40 or fewer hours per week correlated negatively with the level of depressive symptoms. Being younger (β = -0.078, β = -0.099), being a female (β = 2.770, β = 1.268), and possessing a lower level of education (β = -0.315, β = -1.125) were significantly associated with higher level of depressive symptoms in all respondents. Conclusions Both of working excessively long or short hours is significantly associated with the prevalence of depressive symptoms. Establishing proper office hours for employees is critical to improving the quality of working conditions and maintaining good mental health in the workplace.

• Journal of radiological science and technology
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• v.45 no.3
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• pp.255-262
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• 2022

In this study, by analyzing the examination time for each procedure, the appropriate workload of radiologic technologist is analyzed based on the actual examination time in the current clinical setting by comparing with the examination time in the radiology field setting of the health insurance review and assessment service. In addition, this result is introduced into the calculation of relate value units; it was attempted to provide accurate and objective evidence in the field of radiology. From May 2020 to December 2021, the study retrospectively investigated the examination times recorded in the electronic medical record and picture archiving and communication system at 5 tertiary general hospitals and 1 general hospital. The total of 16 examination parts are applied in this study, including the head, sinuses, chest, ribs, abdomen, pelvis, cervical, thoracic, lumbar, shoulder, elbow, wrist, hip, femur, knee, and ankle. The minimum number of images that could be obtained per radiation generator was 3.6 images for one hour, and the maximum was 6.4 images. When 50% median of procedure time is calculated, the minimum number of images that could be obtained was 16.7 images and maximum was 35.3 images; in addition, minimum examination time is 1.7 minutes, and maximum time is 3.6 minutes. In conclusion, it is judged that there will be insufficient explanation time for basic infection instructions such as hand hygiene during the examinations in current clinical practice. It is believed that radiologic technologists will contribute to providing higher-quality of radiation examination services to the public by complying with guidelines for work and setting appropriate workload on their own.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.464-470
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• 2023

Objectives: This study evaluated occupational exposures to noise and heat stress during routine non-outage works in three coal-fired power plants in the Republic of Korea. Methods: The data were collected during the summer of 2020. Full shift noise exposure of 52 workers were measured using noise dosimeters. Heat stress of 16 worksites were measured for 70 minutes using wet-bulb globe temperature monitors. Results: The noise dosimetry results revealed time-weighted averages that ranged from 47.5 to 88.9 dBA. 2 out of 52 noise measurements exceeded 85 dBA. Based on the arithmetic mean, the coal service group showed the highest level at 80.2 dBA by job tasks. Noise exposures exceeding 85 dBA were measured in the coal service and plant operator group. Heat stress index measurements ranged from 20.3℃ to 37.2℃. 1 out of 9 indices measured in coal facilities and 4 out of 7 indices measured in boiler house exceeded 1 hour TWA during moderate work. Heat stress indices measured from boiler houses were significantly higher than those measured from coal equipment. Conclusions: The results show that overexposure to noise and heat stress may be encountered during routine non-outage work activities in coal-fired power plants. Appropriate actions should be taken to reduce future health outcome from occupational exposure to noise and heat stress in the industry.

• Korean Journal of Culture and Social Issue
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• v.13 no.2
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• pp.33-54
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• 2007

This study was performed to develop a group counseling program for the South Koreans and the North Korean defectors to identify mutual cultural characteristics and personal traits, and to acquire adaptation capacity for the other's culture and interpersonal relationship. And then we validated the effect of this group program. This program was based on the existing program even if that was not validated through research work. Actually this program was for encouraging the South Koreans and the North Korean defectors to acquire interpersonal ability through mutually dependent and cooperative work based on the equal status naturally and to adjust themselves to corresponding culture. Each session continued for 1.5 hour per week. And the sessions were done for 4 weeks. This research was analysed, and the results were compared with control group's results. The results showed that treatment group revealed significantly positive outcomes than control group. But, five participants among the North Korean defectors were dropped out in the course. So North Korean defectors' credibility got lowered.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.168-175
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• 2011

Construction accidents are major problem in Turkish Construction industry and especially fatally rates are very high. Current legislative system on occupational safety in Turkey enforces employers to implement safety measures as well as safety management systems. However level of consciousness in the industry is unsatisfactory and safety are perceived as extra cost and unnecessary expenditure. Moreover, especially in small residential building constructions which have a big share in the industry and unfortunately safety measures to mitigate or abate construction risks do not exist. The study focuses on small residential building construction sites and in the scope of this study, thirty building projects are examined. For each building project, project cost including labour and material costs, service and consultancy costs for mechanical, electrical systems as well as architectural and structural services, costs for supervision and finally general expenditures for construction site facilities were calculated. On the other hand, occupational safety costs for personal protective equipment, collective protective measures, consultancy and training were determined. Work breakdown structures were established and for each work item firstly occupational risks were evaluated and furthermore according to risk scores safety measures to be implemented were defined and related costs were calculated. The study gave results for total safety cost on average, in terms of percentage of total project cost (3.73% of total project cost), safety cost per man-hour (0.40 USD) and safety cost in terms of unit construction area (11.60 USD per square meter). Since safety management is a part of whole project management process, study gives suggestions and techniques to calculate safety costs and implement safety measures as a part of project management service for professionals. Authors believe that suggested approach may easily developed by the usage of more data to establish a model for estimation not only for building construction sites but also for all construction projects.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.8-13
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• 2024

Objectives: To evaluate the levels of exposure to organic compounds during aircraft disinfection and seat cover replacement operations. Methods: According to the working schedule, organic compounds were collected using activated carbon tubes and then analyzed by GC/FID and GC/MSD. Results: In the disinfection task, the main substances listed in the material safety data sheet (MSDS) of the disinfectant were not detected. However, 1-bromopropane, which had been used in the previous task of replacing seat covers, was detected at a level of 2.37 ppm at the measurement time. During seat cover replacement, bonding workers were exposed to 2.48 ppm on an eight-hour time-weighted average, and seat cover replacement workers were exposed to 0.22 ppm. Conclusions: It is necessary to ensure the reliability of MSDS. A work environment management system is necessary when different companies alternate working in the same place.

• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.623-630
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• 2020

Objective : A primary degenerative sagittal imbalance has been considered because of unique lifestyles such as the prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Previous papers have reported that sagittal imbalance disease is often seen distinctly in the farming districts of "oriental" countries such as Korea and Japan. However, this finding was only evaluated with the use of X-ray, and other factors such as magnetic resonance imaging (MRI), muscle volume, compression fracture, and laboratory results were not considered. Thus, using these, we evaluate the agricultural work-associated factors for Korean elderly spinal sagittal imbalance. Methods : We recruited 103 Korean participants who had a sagittal vertical axis (SVA) of >5 cm in this Korean Elderly Sagittal Imbalance Cohort Study. The following were evaluated : radiological parameters, MRI, compression fracture, vitamin D, parathyroid hormone, C-terminal telopeptide, osteocalcin, bone mineral density and muscle fatty change, muscle volume, and health-related quality of life from patients' survey. Moreover, in this survey, the farmers' annual working hours were investigated. Subsequently, we analyzed the associated factors for spinal sagittal imbalance depending on occupation. Results : A total of 46 participants were farmers, and the others were housewives, sellers, and office workers. The farmer group had more SVA (141 vs. 99 mm, p=0.001) and pelvic tilt (31° vs. 24°, p=0.004) and lesser lumbar lordosis (20° vs. 30°, p=0.009) and thoracic kyphosis (24° vs. 33°, p=0.03) than non-farmer group. A significantly positive correlation was noted between the working hour and SVA in the farmer group (p=0.014). The visual analogue scale score for back pain (8.26 vs. 6.96, p=0.008) and Oswestry Disability Index (23.5 vs. 19.1, p=0.003) in the farmer group were higher than that in the non-farmer group, but the Short Form-36 score was not significantly different between the two groups. The Mini-Mental State Exam score was significantly lower in the farmer group than in the non-farmer group (24.85 vs. 26.98, p=0.002). Conclusion : The farmer group had more sagittal imbalance and back pain in proportion to the working hours even though the muscle and bone factors and general laboratory condition were not significantly different between the two groups. These results supported that the long hours spent in the crouched posture while performing agricultural work were a risk factor for severe sagittal imbalance.