• Korean Security Journal
• /
• no.32
• /
• pp.205-225
• /
• 2012

This study is to present an improvement of facility security through the evaluation of facility security operation level. To fulfill the purpose of the study, a survey of some facilities was conducted and the result was analyzed as follows; First, although security personnels were deployed in the facilities, the level of security personnel operation was relatively low. Second, job education training level was relatively proper, that is relevant to the result that show the level of service mind and the working mind of security personnel were proper, also relevant to the relatively good work shift system. Third, although situation room was operated well, the level of restricted area set-up and access control of visitor were low, and the level of article inspection and vehicle access control were very low. Forth, the level of security manual application that include detailed security method and procedure was proper. But accident prevention and response manual application was lower than security manual application, that show preparation for fire and negligent-accident is passive. For the improvement of facility security, the high level part and low level part in the survey result could be merged. For example, we could specify factors that show low level in the survey such as security personnel operation, access control of visitor and vehicle, article inspection, accident prevention and response in the security manual and promote education circumstance that show high level.

• Journal of Science Education
• /
• v.39 no.2
• /
• pp.290-305
• /
• 2015

In this study, we analyzed exhibitions and programs of Daegu National Science Museum in terms of levels of science communication and domains of scientific literacy. Also, we surveyed visitors' perceptions on the exhibitions. As results of analysis on science communication level, 48.3% of exhibitions and programs corresponded to the 1st generation level, 49.0% corresponded to the 2nd generation level, and 2.7% corresponded to the 3rd generation level. In terms of domains of scientific literacy, the contents on 'design world' and 'the nature of technology' got a majority. Also, the results of visitors' perceptions on the exhibitions showed they preferred active exhibitions, that is the 2nd generation. It is recommended to develop more 3rd generation exhibitions and programs based on the paradigm shift about the role of science museums. And it is also recommended to carry out the task to raise consciousness of citizens about scientific literacy and science communication.

• The Journal of the Korea Contents Association
• /
• v.7 no.5
• /
• pp.156-165
• /
• 2007

The concepts of static seat allocation model has been used widely in the air transportation industry, and proven as a good concepts for managing perishable assets. The paper analyzed, in realistic environment, the volume of Accept Demand and Reject Demand through several times' simulation experiments at each fare level by using C-Program analyzing process applied to upward and downward models of demand, to analyze the change of fare level when upward and downward shifts of fare levels' demand happen at once. As a consequence, I concluded that the revenue of the case to consider the both shifts of demand at each fare level is bigger than that of the case to consider the single shift of demand at each fare level, except the case to downsize the seat allotment at very low price when supply is bigger than demand, with developing a general model concerned with plural fare levels.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.1
• /
• pp.27-35
• /
• 2005

This study was carried out to evaluate the characteristics of petroleum refinery workers' exposure to organic solvents. Exposure assessment was conducted by full shift-based long term personal sampling(TWA-P) and task-based short term personal sampling(STEL-P) strategy. Major organic solvents that workers can be exposed are various, varying from C3~C12, and this study focused on 11 kinds including benzene, considering toxicity and concentration level. In comparison with two sampling results, STEL-P shows a significant(p<0.001) excess of exposure level rather than TWA-P. As the potential risk index for benzene is calculated as 16, benzene should be set the highest priority for control in petroleum refinery industry. The tasks with the highest benzene exposure level were de-watering(AM;99.8 ppm), draining(AM;19.6ppm), sampling(AM;16.2ppm), and manual gauging(AM;15.02ppm). Petroleum refinery workers' exposure pattern to organic solvents differs by tasks performed, and some task has a high risk of temporary extreme exposure. Therefore, traditional 8-hour TWA sampling strategy have possibility of underestimation of exposure level of workers in petroleum refinery.

• Korean Journal of Adult Nursing
• /
• v.25 no.2
• /
• pp.157-169
• /
• 2013

Purpose: This study was to examine the impact of acculturation and social support on the mental health among Korean-American registered nurses. Methods: Data were collected with a convenience sample of 203 Korean-American registered nurses living in New York state and New Jersey state from 8th May to 25th August in 2012. The structured questionnaires measured the degree of acculturation, social support, and mental health. Data analysis was conducted using t-test, ANOVA, Pearson correlation efficient, and Stepwise multiple regression. Results: Lower level of integration and higher level of marginalization were associated with the lower mental health. Social support was also positively related to mental health and had mediating effect on the relationship between acculturation and mental health. The five variables, including participants' educational background, work shift, integration, marginalization, and social support were significant to predict the level of mental health among Korean-American registered nurses, accounting for 41% of the variability. Conclusion: The results imply that higher level of social support and strong identity of both home and host culture will enable Korean-American registered nurses to maintain sound mental health.

• Safety and Health at Work
• /
• v.11 no.2
• /
• pp.199-206
• /
• 2020

Background: In a wide range of industries, noise-induced hearing loss remains one of the most prevalent occupational problems. This study aimed to assess the noise exposure level and associated factors of hearing loss among textile workers in Yangon Region, Myanmar. Methods: A cross-sectional study was conducted at a Textile mill (Thamine), Yangon Region, from April to December 2018. In total, 226 workers who were randomly selected from 3 weaving sections participated in face-to-face interviews using a structured questionnaire. A digital sound level meter and pure-tone audiometer were used for the assessment of noise exposure level and hearing loss, respectively. Logistic regression analysis was performed to assess the associated factors of hearing loss. Results: In total workers, 66.4% were exposed to ≥85 dB(A) of noise exposure, and the prevalence of hearing loss was 25.7%. Age ≥35 years, below high school education, hearing difficulty, tinnitus, hypertension, > 9 years of service duration in a textile mill were positively associated with hearing loss. After adjusting confounding factors, age ≥35 years (adjusted odds ratio = 6.90, 95% confidence interval = 3.45-13.82) and tinnitus (adjusted odds ratio = 2.88, 95% confidence interval = 1.13-7.37) were persistently associated with hearing loss. Conclusion: Providing occupational hazard education and enforcement of occupational safety regulations should be taken to decrease the noise exposure level. The regular audiometry test should be conducted for assessment of hearing threshold shift. The employer needs to implement a hearing conservation program in workplace when noise exposure reaches or exceeds 85 dB(A) for 8 hours.

• Journal of Preventive Medicine and Public Health
• /
• v.27 no.3 s.47
• /
• pp.487-504
• /
• 1994

A cross-sectional study was performed to evaluate the effects of chronic low-dose solvent on neurobehavioral performance of 118 male car painters. A control group of 113 workers matched for age was selected from different sections of the factory. The mean age and the mean duration of employment were 33 years and 6.7 years in both groups. Mean years of education were 11.4 years in car painters and 11.8 years in controls. Each worker completed a medical and occupational questionnaire and four tests of Swedish performance evaluation system. These included simple reaction time, symbol digit, digit span and finger tapping speed. Althougth the mean duration of employment was 6.7 years, comparison of mean performance showed a significantly poorer performance on simple reaction time (p<0.05), symbol digit(p<0.01) and digit span(p<0.05) in car painters. In univariate analysis, age and educational level contributed to poorer performance on symbol digit and digit span. Smoking appeared to slow finger tapping speed in car painters. Performance of four tests of car painters exposed to high level of solvent was poorer than that of car painters exposed to low level. In multiple regression models, controlling for age, alcohol, smoking and shift work, solvent exposure was found to be associated with performance of simple reaction time, symbol digit and digit span and exposure to high level of solvent was related to poorer performance of symbol digit and digit span.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.6
• /
• pp.478-487
• /
• 2003

In this paper, a type and special feature of Multi-level inverter used in medium-voltage and high-capacity motor driver is introduced. Especially, a power quality and structural advantages of H-Bridge Multi-level inverter is described. It presented the specific structure of power circuit, design method, controller composition and PWM techniques of the cascaded H-Bridge Multi-level inverter which is developed. The feasibility of the developed product based on 3,300V lMVA 7-level H-bridge inverter was studied by experiments and we get conclusion that 1)generate of near-sinusoidal output voltage; 2)is low dv/dt at output voltage; 3)reduce the harmonic injection at input; Experiment demonstrate that it is very economical in productivity because of using the existing production technique and examination equipment, and has the reliability and a good maintenance due to the structure of Power Cell unit combination as well as low cost IGBT.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.44 no.2
• /
• pp.140-152
• /
• 2021

During the shift from gasoline vehicles to electric ones, auto parts manufacturing companies have realized the importance of improvement in the manufacturing process that does not require any layout changes nor extra investments, while maintaining their current production rate. Due to these reasons, for the auto part manufacturing company, I-company, this study has developed the simulation model of the PUSH system to conduct a process analysis in terms of production rate, WIP level, and logistics work's utilization rate. In addition, this study compares the PUSH system with other three manufacturing systems -KANBAN, DBR, and CONWIP- to compare the performance of these production systems, while satisfying the company's target production rate. With respect to lead-time, the simulation results show that the improvement of 77.90% for the KANBAN system, 40.39% for the CONWIP system, and 69.81% for the DBR system compared to the PUSH system. In addition, with respect to WIP level, the experimental results demonstrate that the improvement of 77.91% for the KANBAN system, 40.41% for the CONWIP system, and 69.82% for the DBR system compared to the PUSH system. Since the KANBAN system has the largest impacts on the reduction of the lead-time and WIP level compared to other production systems, this study recommends the KANBAN system as the proper manufacturing system of the target company. This study also shows that the proper size of moving units is four and the priority allocation of bottleneck process methods improves the target company's WIP and lead-time. Based on the results of this study, the adoption of the KANBAN system will significantly improve the production process of the target company in terms of lead-time and WIP level.

• Journal of the Ergonomics Society of Korea
• /
• v.33 no.4
• /
• pp.289-297
• /
• 2014

Objective: The purpose of this study is to identify the incidence risk of cardiovascular disease (CVD) in the workplace, and to suggest the prediction models for level of CVD incidence risk. Background: CVD can be caused by various factors related to personal habits such as diet and exercise, or genetics. However it can also be caused and aggravated by work, making the elimination of such risk factors at work crucial disease (KOSHA, 2013). Method: The distribution of CVD risk assessment levels of 162 workers was compared with the acquired medical examination data to discuss the necessity of assigning additional risk factors. Two alternative risk assessment models were given to enhance the accuracy of the evaluation; adjusting risk scores given in the KOSHA GUIDE H-1-2013 (alternative 1) and building a matrix of KOSHA GUIDE H-1-2013 and risk assessment results based on work condition levels (alternative 2). To verify the suggested models, medical examination results of 12 workers approved of convalescence were referred to. Results: The second alternative showed more relevance between the results and workers approved of convalescence in predicting the risk group when applied to actual heath examination data from the approved workers. The power of description of the new method for determining the risk of CVD incidence, 83.3%, is higher than that of KOSHA GUIDE H-1-2013, 25%. Conclusion: Results of this study imply that more approved workers had been from unmanaged normal groups than managed risk groups, raising the importance of CVD management. Application: The new prediction model considering working time and shift work developed in this study is expected to be a fundamental data for risk analysis and management of CVD in the workplace.