• Journal of environmental and Sanitary engineering
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• v.11 no.3
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• pp.1-7
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• 1996

Mandelic acid is the major metabolite and phenylglyoxylic acid is the minor metabolite of styrene in human. This study was conducted to investigate the correlation between exposure concentrations of styrene and concentration of the metabolites in urine The concentrations of metabolites in urine and exposure concentrations were measured in 60 workers who were occupationally exposed to styrene in FRP industry as well as paint industry and musical instrument manufacturing industry and the concentrations of metabolites in urine ware measured in 90 workers not occupationally exposed to styrene for review the background level in the unexposed population. The results obtained were as follows; 1. The mean exposure concentration is 16.6 $\pm $12.2 ppm (range 0.4-49.9ppm) in the styrene exposed workers. 2. The concentration of mandelic acid in urine collected at the end of shift from worker exposed 8 hours to 50ppm of styrene, based on extrapolation from correlation equations was 578.5 mg/g creatinine and 176.8 mg/g creatinine for next morning urine, the concentration of phenylglyoxylic acid in urine collected at the end of shift was 291.1 mg/g creatinine, 177.9 mg/g creatinine in next morning urine. In the sum of mandelic acid and phenylglyoxylic acid in the urine 870.2 mg/g creatinine in urine sampled at the end of shift corresponds to an exposure of 50ppm of styrene and 366.0 mg/g creatinine for next morning sample corresponds to 50ppm. 3. The correlation of the degree of exposed with sum concentration of mandeliacid and phenylglyoxylic acid in the urine was better(r=0.079 for end of shift, r=0.78 for next morning) than the correlation with single determinant measurement in urine(r=0.75 for mandelic acid at end of shift, r=0.73 for mandelic acid at next morning, r=0.69 for phenylglyoxylic acid at end of shift, r=0.62 for phenylglyoxylic acid at next morning). The monitoring of sum concentration of mandelic acid and phenylglyoxylic acid in urine is a valuable indicator of time weighted average daily exposure ti styrene. And the exposure standard of urinary metabolites produced by styrene should be set, in distinction urine at the end of shift from urine at next morning.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.1101-1107
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• 2005

Mold industry has the difficulty to employ young people as the successors of the skilled workers, because it has been regarded as a 3D-jobs(dirty, difficult, and dangerous). To overcome this situation, thus, manufacturing technologies maintained in the factory should be systemized, and engineering systems should support unskilled workers to do their jobs without any difficulty. As a research of developing the supporting system, this study proposes a decision support system that facilitates unskilled workers to easily select high quality NC-data, as well as to increase productivity. The proposed system is assumed to follow a CAM operation scenario that consists of next three steps: 1) identifying several process plans and enumerating feasible unit machining operations (UMOs) from material and part surface information, 2) creating all feasible NC-data based on UMOs using a commercial CAM system, 3) selecting the best NC data among the feasible NC data using four screening criteria, such as machining accuracy, machining allowance, cutting load, and processing time. A case study on the machining of a camera core mold is provided to demonstrate the proposed system.

• Physical Therapy Rehabilitation Science
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• v.10 no.1
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• pp.48-54
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• 2021

Objective: The purpose of this study is to investigate the effect of exercise programs according to various music tempo on pain, posture, and function of automobile parts manufacturing workers. Design: Two-group pretest-posttest design. Methods: This study was an exercise program tailored to the prevention and treatment of musculoskeletal diseases were performed for a total of 4 weeks and 3 times a week for 60 minutes. The exercise program consisted of customized exercises according to the characteristics of the subject's musculoskeletal system. The subject provided music during the exercise program, and the group who applied the fast tempo music listened to the music of 120~140 bpm, and the group who applied the slow tempo music listened to the music of the low tempo of 60~80 bpm. Results: Significant differences were found in pain and physical function before and after the fast tempo music group and the slow tempo music group (p<0.01). However, there was a significant difference in posture characteristics only in the fast tempo music group (p<0.01). In terms of pain, physical function, and posture characteristics, the fast tempo music group showed significant improvement compared to the slow music tempo group (p<0.05). Conclusions: A customized exercise program using fast-tempo music and slow-tempo music to workers in the automobile parts manufacturing industry, significant differences in pain, physical function, and posture characteristics applied with fast-tempo music were found. In the future, applying an exercise program with a fast tempo is expected to help improve musculoskeletal disorders.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.305-312
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• 1974

Studies on 66 industrial accidents happened in a battery manufacturing industry during a year of 1973 were carried out. The results obtained are follows, 1. Majority of employees of this industry was occupied by yong woman aged between 20-24. 2. Incidence rate, frequency rate and severity rate of the accidents was 36.8 per 1,000, 12.8 per 100,000 labour day and 0.3% respectively. Anual average days of lost due to accidents was 18.0 days. 3. Accidents happened more frequently in male than female, and happened most frequently in age between 30-34. 4. As to type of work, 47.9% of the accidents happened on hand operating workers. This was the same in both sex. 5. Accidents happened mainly during 2-3 hours latter from work starts in both morning and afternoon work, 6. 63.6% of the accidents happened on hands in both sexes and followed by lower extremities. 7 Surface wounds like as laceration, cut and abrasion were the main types of injury occupying 31.8% and followed by burn at 24.2%. 8. 54.5% of accidents needed 1-2 weeks to heal the injury and heavy injury needed more than 5 weeks was only 9.1%. 9. Accidents happened most frequently in employees who served between 2-3 years in this industry, but observing of sex difference. it was most frequent in male who served more than 4 years whereas less than 6 months in female.

• Safety and Health at Work
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• v.7 no.2
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• pp.156-160
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• 2016

Background: Workers in pesticide manufacturing industries are constantly exposed to pesticides. Genetic biomonitoring provides an early identification of potential cancer and genetic diseases in exposed populations. The objectives of this biomonitoring study were to assess DNA damage through comet assay in blood samples collected from industry workers and compare these results with those of classical analytical techniques used for complete blood count analysis. Methods: Samples from controls (n = 20) and exposed workers (n = 38) from an industrial area in Multan, Pakistan, were subjected to various tests. Malathion residues in blood samples were measured by gas chromatography. Results: The exposed workers who were employed in the pesticide manufacturing industry for a longer period (i.e., 13-25 years) had significantly higher DNA tail length ($7.04{\mu}m$) than the controls ($0.94{\mu}m$). Workers in the exposed group also had higher white blood cell and red blood cell counts, and lower levels of mean corpuscular hemoglobin (MCH), MCH concentration, and mean corpuscular volume in comparison with normal levels for these parameters. Malathion was not detected in the control group. However, in the exposed group, 72% of whole blood samples had malathion with a mean value of 0.14 mg/L (range 0.01-0.31 mg/L). Conclusion: We found a strong correlation ($R^2=0.91$) between DNA damage in terms of tail length and malathion concentration in blood. Intensive efforts and trainings are thus required to build awareness about safety practices and to change industrial workers' attitude to prevent harmful environmental and anthropogenic effects.

• Korean Journal of Labor Studies
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• v.17 no.1
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• pp.1-36
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• 2011

The purpose of this study is to analyze the effect to financial outcome and workers' outcome, using the manufacturing industry database of Human Capital corporate Panel from Korea Research Institute for Vocational Education & Training. Especially, this study used the typology of Lean production and Autonomous team production, that are the typical form of alternative work organization, to analyze. In the case of domestic manufacturing industry, individual participation practices, that have the main characteristics such as QC or suggestion system, is expanded. Therefore, with the reference of Lean production, Autonomous Team Production and the Taylor system are compared and analyzed, considering the characteristics of Socio-technical System. As a result, it is showed that the Lean production and Autonomous Team Production as a alternative work organization are more positive about the organizational performance and workers' outcome than the taylor system. However, when Lean production and Autonomous Team Production are compared, it is showed unsignificant distinction to the effect of organizational performance. Meanwhile, Lean production showed more negative effect on the every dependent variables such as working hours, income, job satisfaction, and organizational commitment as workers' performance than the Autonomous Team Production. Although the common ideas and belief is that the Lean Production is superior for the quality and organizational performance improvement, it is implied the possibility that there is some damaged workers' performance on the hidden side of that mechanism.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.198-207
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• 1994

In order to evaluate the effectiveness of environmental intervention of work place, metal mercury concentration in air and in urine of the total 43 workers for 3years from December 1991 to October 1993 in a fluorescent lamp manufacturing industry exposed to mercury, was measured before and after implementation of controls such as establishing exhaust ventilation at the department of exhaustion, coating the floor of work place with epostane, cleaning of the floor, improved housekeeping, and etc. The results were as follows. 1. Before the intervention(December 1991) 39.0% exceeded metal mercury Threshold Limit Value(TLV, $0.05mg/m^3$). After the intervention(October 1993) 10.0% exceeded TLV and geometric mean of mercury in air was $0.1mg/m^3$, and showed effectiveness rate of intervention to be 74.4% 2. After the intervention, geometric means of mercury concentrations in air were 0.013, $0.019mg/m^3$ and showed effectiveness rate of intervention to be 76.6%, 65.5% in A factory(right tube lamp)and at exhaustion department, respectively, A follow up survey fround statistically significant reductions in mercury concetration in air three years later. 3. Mercury concentration in urine of 11 workers(29.7%) exceeded warning level of $100{\mu}l/l$ before the intervention. After the intervention, of 3workers(8.8%) exceeded warning level and geometric mean of mercury concentration($26.5{\mu}l/l$) in urine was 2.4 times than that of before the intervention. Geometric means of mercury concentrations in urine of workers at exhaustion department, at sealing and aging department were 44.0, $77.7{\mu}l/l$, respectively and they decreased 2.3, 3.2 times than that of before the intervention.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.265-275
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• 2024

Smart factory is a remarkable development from traditional manufacturing systems to data-based smart manufacturing systems that can connect and process data continuously, collected from machines, production equipment to production and business processes, capable of supporting workers in making decisions or performing work automatically. Smart factory is the key and center of the fourth industrial revolution, combining improvements in traditional manufacturing activities with digital technology to help factories achieve greater efficiency, contributing to increased revenue and reduce operating costs for businesses. Besides, the importance of smart factories is to make production more quality, efficient, competitive and sustainable. Businesses in Vietnam are in the process of learning and applying smart factory models. However, the number of businesses applying the pine factory model is still limited due to many barriers and difficulties. Therefore, in this paper we conduct a survey to assess the needs and current situation of businesses in applying smart factories and propose some specific solutions to develop and promote application of smart factory model in Vietnamese businesses.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.16-25
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• 2023

There are various types of foreign object debris (FOD) in the aviation industry. Tools lost by workers can act as a risk factor throughout aircraft operation, manufacturing, and maintenance fields. Accidents caused by tools lost due to workers' carelessness continue to occur throughout the aviation industry. Aviation-related institutions such as FAA and EASA have established tool control regulations and systems to prevent FOD occurrence. However, in Korea, related regulations and procedures are insufficient. A systematic and effective tool control system is required for reliable manufacturing, airworthiness, operation, and maintenance of aircraft. In this paper, tool control regulations and procedures of domestic and foreign air traffic authorities and aviation industry-related organizations were studied. A wireless communication-based tool control system was proposed based on the NAS 412's tool control regulations certified by the National Standards Association.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.852-857
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• 2011

The shipbuilding industry needs automation and mechanization to solve reduction of skilled workers and labor shortage. Ship manufacturing process is the lack of automation than standardized manufacturing field. In this paper, we design and development an process automation system for hand rail production. Mechanical parts of the cutting process was designed with efficiency, productivity and reliability, CATIA and ANSYS, the stability of the mechanical structure was confirmed. System control using a PCNC controller to provide an open and scalable, and operate using touch-screen display control and monitoring of the system was performed. The automatic system successfully passed the driving test and processing test, and it showed an excellent performance.