• Journal of the Korea Society for Simulation
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• v.17 no.2
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• pp.63-74
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• 2008

The design of best efficient production process is common requirements of the production strategy department and the process planning department to maximize the revenue and accomplish target production volumes in the production periods. And they use several general methods for that-line-balancing, removing of the bottle-neck process, facility ramp-up, increasing of the worker's utilization, etc. But, those methods have depended on analytic, static and arithmetic calculations, yet. So, irregular work-waiting time causing the delay time isn't include in extracting production capacity, especially in the line production process. The work-waiting time is changed irregularly along the variation of each machine and very important for calculate real product lead-time and forecasting target production volumes. At this thesis, i'm going to mention the importance of the delay time of conveyor system which can be extracted by discrete-event simulation. And suggest it as a new main variable that must be considered at designing new production system. Then experimented and tested that's effects in the H-company case, conveyor based line production process.

• Korean Journal of Social Welfare Studies
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• v.48 no.4
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• pp.221-249
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• 2017

This study aims to investigate determinants that affect job retention of injured workers depending upon types of return to work in order to suggest define the intervention priority for those who returned to original works and for those who did not. After constructing explaining variables based on literature reviews, determinants were verified analyzing 1,292 people using Panel Study of Worker's Compensation Insurance(PSWCI) data. The job retention period turned out to be 46.6 months for those who returned to original work and 34.2 month for those who returned to new works. Injured workers who return to new works tend to have more unemployment experiences. As a result of Cox proportional regression analysis, the longer it takes to return to work, the longer both groups tend to retain after the accident. Age, recuperation period, health status, psycho-social rehabilitation, education and occupational training also affect on job retention probability for those who return to new work. Based upon the analyzed result, setting up an adequate duration for return-to-work, intervention for injured workers who experienced vulnerable working condition before the accident and continuous case management after return-to-work are suggested.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.141-158
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• 2019

Objectives: An adverse outcome pathway is a biological pathway that disturbs homeostasis and causes toxicity. It is a conceptual framework for organizing existing biological knowledge and consists of the molecular initiating event, key event, and adverse output. The AOP concept provides intuitive risk identification that can be helpful in evaluating the carcinogenicity of chemicals and in the prevention of cancer through the assessment of chemical carcinogenicity predictions. Methods: We reviewed various papers and books related to the application of AOPs for the prevention of occupational cancer. We mainly used the internet to search for the necessary research data and information, such as via Google scholar(http://scholar.google.com), ScienceDirect(www.sciencedirect.com), Scopus(www.scopus. com), NDSL(http: //www.ndsl.kr/index.do) and PubMed(http://www.ncbi.nlm.nih.gov/pubmed). The key terms searched were "adverse outcome pathway," "toxicology," "risk assessment," "human exposure," "worker," "nanoparticle," "applications," and "occupational safety and health," among others. Results: Since it focused on the current state of AOP for the prediction of toxicity from chemical exposure at work and prospects for industrial health in the context of the AOP concept, respiratory and nanomaterial hazard assessments. AOP provides an intuitive understanding of the toxicity of chemicals as a conceptual means, and it works toward accurately predicting chemical toxicity. The AOP technique has emerged as a future-oriented alternative to the existing paradigm of chemical hazard and risk assessment. AOP can be applied to the assessment of chemical carcinogenicity along with efforts to understand the effects of chronic toxic chemicals in workplaces. Based on these predictive tools, it could be possible to bring about a breakthrough in the prevention of occupational and environmental cancer. Conclusions: The AOP tool has emerged as a future-oriented alternative to the existing paradigm of chemical hazard and risk assessment and has been widely used in the field of chemical risk assessment and the evaluation of carcinogenicity at work. It will be a useful tool for prediction, and it is possible that it can help bring about a breakthrough in the prevention of occupational and environmental cancer.

• Anxiety and mood
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• v.15 no.1
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• pp.45-52
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• 2019

Objective : The objective of this study is to determine the effects of fear of Middle East respiratory syndrome (MERS) on socio-psychological health during an outbreak of MERS and the post-traumatic stress as a mediator on the relationship between stress and socio-psychological health. Methods : Visual Analog Scale, Impact of Event Scale -Revised, Psychosocial well-being index short form was implemented for 150 medical persons who worked at the hospital in which exposure to MERS cases had been confirmed and 96 ordinary people. A Pearson correlation coefficient and a hierarchical multiple regression was carried out to confirm the effect of fear of MERS and the mediating effect of post-traumatic stress between fear and socio-psychological health. Results : The higher the fear, the lower the socio-psychological health in both healthcare workers and the public (r=0.32, p<0.01) and the higher post-traumatic stress (r=0.32, p<0.01). But, the research results showed that only healthcare workers had a partially mediating effect of post-traumatic stress in the relationship between fear and socio-psychological health (${\beta}=0.45$, t=6.33 p<0.001), (${\beta}$ value : 0.39>0.26). Conclusion : This study demonstrated that the post-traumatic stress can indirectly lead to a negative effect on the socio-psychological health of healthcare workers when under the fear of MERS and shows adverse effects on psycho-social wellbeing. This suggests that clinical intervention and psycho-social approach aiming at reducing post-traumatic stress is important to maintain mental health during crisis development.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.556-565
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• 2014

Objectives: This study is aimed at inquiring into the grasp of real condition of working environment and improvements by calculating the hypertension distribution consequent on job stress risk and exposure level of alleviating factors. In addition, this study is intending to estimate the hypertension distribution through socio-demographic factors and level of stressors occurring at working environment, such as high workload, low control, low support, job insecurity, long working hours, low income. Methods: This study estimated the hypertension distribution using the tertiary Korean Working Conditions Survey data, and conducted comparative analysis according to the category of individual questionnaire items using odds ratio. Result: As a result of study, it was found that in the event that working environment satisfaction is low and business & an immediate superior's attitudes are negative, the hypertension distribution was high. Particularly, it was found that physical risk factor musculoskeletal risk factor, and mental risk factor in a workplace were all increasing the hypertension distribution. Conclusions: With the aged workers' labor market participation ratio increasing, hypertension could be a major issue in the field of Occupational Safety and Health. Thus, it's necessary that the relevant employer should lower the hypertension distribution through creation of pleasant working environment and inducement of workers to improve in the relations with their superiors. As for the uppermost limit of this study, there is a limit to clarifying the mechanism of hypertension through multivariate statistics analysis because it's difficult to establish causal relationship by individual questionnaire item as the working conditions survey is made by cross-sectional study. In the follow-up research, this study is going to do research on the mechanism of hypertension through questionnaire supplementation and in-depth analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1265-1270
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• 2008

In the parts including a vehicle, standard and contents are different according to type of automobile. Although the parts are same, the quality and requirement all are different according to vehicle production version. Also the business is shared at each department in a production line. So if a part is changed, each team or the department must recognize information which is changed. But currently if the event can occur at like this each department, because of parts management through handwork, the unification of information is difficult. Therefore in this paper, we applied POP systems at the automobile part enterprise and constructed POP based the automobile part productive integrated management system. This system supported productive information from mechanical, equipment, worker, and products in real-time and data update also is processed automatically. When this system is introduced, work time and cost remarkably will be reduced.

• Anxiety and mood
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• v.6 no.1
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• pp.65-70
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• 2010

Objectives : Indirect contact with trauma may occur when a person empathically listens to detailed descriptions, exposing the person to intense emotional pain from trauma victims. Although less severe than direct trauma, indirectly traumatized persons may experience the same fear, rage, and despair as direct trauma victims. This phenomenon has been variously termed vicarious trauma, traumatic countertransference, burnout, compassion fatigue, and secondary traumatic stress. Using a psychiatric symptoms questionnaires, this study investigated the effects of indirect exposure to co-worker's trauma on the mental health of firefighters who had not directly experienced traumatic events in the previous year. Methods : We administered self-report questionnaires, such as the Impact of Event Scale-Revised (IESR) and Alcohol Use Disorder Identification Test (AUDIT), to firefighters working at two fire stations in a metropolitan city. We analyzed 188 of 232 collected surveys, after excluding falsely entered data (28 cases) and questionnaires by directly-traumatized victims (16 cases). Results : Alcohol consumption and posttraumatic stress disorder (PTSD) symptoms, as determined by the AUDIT and IES-R, were significantly higher in the indirectly-traumatized group. The ratio of high-risk members scoring higher than 23 in IES-R was larger in the indirectly traumatized group, although this was not statistically significant. Conclusion : Alcohol consumption was significantly higher in the indirectly traumatized group. This group also included more members at high risk for PTSD. Further research, with a larger group of indirectly traumatized firefighters and ongoing investigation of PTSD development and other psychiatric symptoms, is needed.

• Journal of Korean Neuropsychiatric Association
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• v.56 no.1
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• pp.28-34
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• 2017

Objectives The purpose of this study was to evaluate psychological effects of an outbreak of Middle East respiratory syndrome (MERS), a newly emerged infectious disease, on doctors. Methods After the MERS outbreak was over, we conducted an online survey of doctors who worked at the hospitals in which exposure to MERS cases had been confirmed or who were directly involved in MERS diagnosis and treatment. The Patient Health Questionnaires-9 (PHQ-9) and the Impact of Event Scale-Revised (IES-R) assessment methods were used to assess the severity of depressive and posttraumatic stress symptoms among the 64 doctors participating in the survey. Results The results of the survey indicate that 26.6% (n=17) of participants exhibited depressive symptoms and 7.8% (n=5) had post-traumatic stress symptoms. The doctors employed at hospitals with MERS cases had higher PHQ-9 and IES-R mean scores than those in doctors were not so employed. In contrast, there was no significant difference in those test scores between doctors who participated directly in MERS diagnosis and treatment and those doctors who did not. Conclusion The survey demonstrated that 28.1% (n=18) of doctors involved in MERS care suffered from depressive or posttraumatic stress symptoms, even though the MERS infection was being controlled. Working at a hospital with MERS cases was the primary determinant of the adverse psychological outcomes among doctors ; however, direct participation in the diagnosis and care of MERS patients was not significantly related to such outcomes.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3824-3836
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• 2021

Workers' safety from radiological exposure in a 1 ton/day capacity spent resin treatment facility was evaluated according to the operating times and outflow rate due to process related leakages. The conservative annual dose based on the operating times of the workers exceeded the dose limit by at least 7.38E+01 mSv for close work. The realistic dose range was derived as 1.62E+01 mSv-6.60E+01 mSv. The conservative and realistic annual doses for remote workers were 1.33E+01 mSv and 3.00E+00 mSv respectively, which were less than the dose limit. The MWR was identified as the major contributor to worker exposure within the 1 h period required for removal of radioactive materials. The dose considering both internal and external exposures without APF was derived to be 1.92E+01 mSv for conservative evaluation and 4.00E+00 mSv for realistic evaluation. Furthermore, the dose with APF was derived as 7.27E-01 mSv for conservative evaluation and 1.51E-01 mSv for realistic evaluation. Considering the APF for leakage from all parts, the dose range was derived as 1.25E+00 mSv-2.03E+00 mSv for conservative evaluation and 2.61E-01 mSv-4.23E-01 mSv for realistic evaluation. Hence, it was confirmed that radiological safety was secured in the event of a leakage accident.

• Journal of IKEEE
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• v.27 no.3
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• pp.225-233
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• 2023

This paper implements a system that monitors human body lifting information in the event of a marine accident. The monitoring system performs ultrasonic communication through a lifting device controller that transmits underwater environment information, and LoRa communication is performed on the water to provide GPS information within 10 km to the control center or mother ship. The underwater lifting controller transmits pneumatic sensor, gyro sensor, and temperature sensor information. In an environment where the underwater conditions increase by one atmosphere of water pressure every 10m in depth, and the amount of air in the instrument decreases by half compared to land, a model of a 60kg underwater mannequin is used. Using one 38g CO2 cartridge in the lifting appliance SMB(Surface Maker Buoy), carry out a lifting appliance discharge test based on the water level rise conditions within 10 sec. Underwater communication constitutes a data transmission environment using a 2,400-bps ultrasonic sensor from a depth of 40m to 100m. The monitoring signal aims to ensure the safety and safe human structure of the salvage worker by providing water depth, water temperature, and directional angle to rescue workers on the surface of the water.