• Korean Journal of Occupational Health Nursing
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• v.12 no.1
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• pp.5-18
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• 2003

The purpose of this study was to survey working conditions of women workers. We conducted a field survey of 504 manufacturing company with many women working from May 13 to June 29, 2002. We focused on only 3 categories of metal, textile and electronics industry. The result were as follows : 1. Subjects were constituted metal 27.0%, textile 37.9% and electronics industry 35.1%. Size distribution was small scale(<50 workers) 38.1%, medium(50-299 workers) 50.2% and large(${\geq}300$ workers) company 11.7%. Women workers' proportion was 43.6% of total workers, 63.8% of total contractors. 2. A medical examination enforcement of contractors workers was very poor in comparison with that of employees(p<0.001). 3. A 53.8% of total companies have conducted shiftwork system and 2-crew 2-shift(12 hours shift system) ranked first, 56.1%(151 companies). 4. Only 61.3% of total companies conducted more than 90 days as legal standard of a maternity leave and only 2.6% of total companies had a day nursery. In conclusion, many strategies for women workers are needed by companies and government. For example, the raising of understanding about maternity protection, social support insurancing of woman worker and occupational health system improvement for contractors and small size companies.

• Journal of Labour Economics
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• v.41 no.4
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• pp.63-105
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• 2018

This paper analyzes the effects of three factors on the firm-size wage premium which have not been considered in previous studies: the worker compositions within firms, the wage differentials between contractors and subcontractors, and the performance pay and rent-sharing behaviors of firms. The main results are as follows. First, even after controlling for the various worker characteristics, the differences in shares of highly educated workers, managers, and professionals between large and small firms make the size-wage premium larger. Secondly, wage differentials between contractors and subcontractors also affect the size-wage premium in the manufacturing sector. Thirdly, high performance pay and active rent-sharing behaviors of large manufacturing firms make the size-wage premium larger. These results imply that a positive matching effect among skilled workers, a structural problem between contractors and subcontractors, and differences in rent-sharing behaviors between large and small firms have affected the firm-size wage premium in the South Korean labor market.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.43-57
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• 1996

To characterize worker's exposure to glass fibers, to find the correlation between airborne total dust concentrations and fiber concentrations and to recommend an appropriate evaluation method for worker's exposure to fibrous dusts in glass wool industry, we carried out this study. Average respirable fiber levels at five factories were 0.013-0.056 f/cc, and fairly below the OSHA PEL, 1 f/cc. A factory showed the lowest airborne fiber level, 0.013 f/cc, which was different significantly from those of other factories of which average fiber concentration was 0.046 f/cc. The cutting and grinding operations of insulation products resulted in higher airborne fiber cocentrations than any other processes(p<0.05). To characterize airborne fiber dimension, fiber length and diamter were determined using phase contrast microscope. The geometric means of airborne fiber lengths were $42-105 \mu m$. One factory had airborne fibers whose length distribution(GM = $105 \mu m$) was different from those of other factories(GM = $42-50 \mu m$). The percentages of respirable fibers less thinner than 3 gm were 38.9-90.9% at four factories, and two factories of them had the higher percentages than others. The findings explain for variation of airborne fiber diameters between factories. On the other hand, between the processes were the difference of fiber-length distributions observed. The cutting and grinding operations showed shorter fiber-length distributions than the fiber forming one. However, fiber-diameter distributions or respirable fiber contents were similar in all processes. The airborne fiber concentrations and the dust concentrations had relatively weak correlation(r=0.25), thus number of fibers couldn't be expected reliably from dust amount. Fiber count is appropriate for assessing accurate exposures and health effects caused by fibrous dusts including glass fibers. Ministry of Labor have established occupational exposure limit to glass fibers as nuisiance dust, but should establish it on the basis of respirable fiber concentration to provide adequate protection for worker's health

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.208-218
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• 2014

Objectives: The major objective of this study was to develop and validate a tier 1 exposure model utilizing worker exposure monitoring data and characteristics of worker activities routinely performed at construction sites, in order to estimate worker exposures without sampling. Methods: The Registration, Evaluation, Authorization and Restriction of Chemicals(REACH) system of the European Union(EU) allows the usage of exposure models for anticipating chemical exposure of manufacturing workers and consumers. Several exposure models have been developed such as Advanced REACH Tools(ART). The ART model is based on structured subjective assessment model. Using the same framework, a tier 1 exposure model has been developed. Worker activities at construction sites have been analyzed and modifying factors have been assigned for each activity. Korean Occupational Safety and Health Agency(KOSHA) accrued work exposure monitoring data for the last 10 years, which were retrieved and converted into exposure scores. A separate set of sampling data were collected to validate the developed exposure model. These algorithm have been realized on Excel spreadsheet for convenience and easy access. Results: The correlation coefficient of the developed model between exposure scores and monitoring data was 0.36, which is smaller than those of EU models(0.6~0.7). One of the main reasons explaining the discrepancy is poor description on worker activities in KOSHA database. Conclusions: The developed tier 1 exposure model can help industrial hygienists judge whether or not air sampling is required or not.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.190-199
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• 2017

The purpose of this study is to propose the standard of health-related fitness evaluation according to the working styles of male manufacturing workers. The subjects were 15,329 male manufacturing workers aged from 40 to 59 years old who had taken a health-related fitness test by K Institution. Health-related fitness components are cardiorespiratory endurance, muscular strength, muscular endurance, flexibility and body composition. We measured Vo2max, grip strength, sit-up, trunk flexion forward, and body fat percentage to ascertain each component. Data were analyzed with Two-way ANOVA, T-test, One-way ANOVA(Scheffe) and Percentile using SPSS version 18.0 program. The analysis results are as follows. First, the health-related fitness of manufacturing workers varied significantly according to their working styles(maximum oxygen uptake : F=88.67(p<.001), grip strength : F=20.09(p<.001), sit-up : F=42.06(p<.001), trunk flexion forward : F=69.44(p<.001), body fat percentage : F=136.75(p<.001)).Therefore, the evaluation standard was set based on the percentile of health fitness items. Second, the average Vo2max, grip strength, and trunk flexion forward of blue-collar workers were higher than those of white-collar workers at all ages. On the other hand, the average sit-up and body fat percentage of white-collar workers were higher than those of blue-collar workers at all ages. Third, these evaluation criteria differed greatly when compared with the results of the National Physical Fitness Survey. Therefore, we have confirmed that the evaluation criteria should be applied differently according to the working style of a worker when evaluating his health-related fitness.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.118-123
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• 2008

Weakness process can be called ferrule array and epoxy filling process at connector manufacturing process, and a lot of problems happen as think as general manufacturing process at early investment. Wished to improve this and working environment mend of worker on childhood(planning phase) and problem that is happened at done ferrule array and epoxy injection by emphasis target. By ferrule sorting and Improvement of epoxy filling process, bring authoritativeness elevation of product by fraction defective decrease of product by sized work along with productivity elevation. On the other hand, working jigs are various in characteristics of optical connector manufacturing line. There have been lots of restriction in practice because the applicability of this system is only for single type model though the network should be smooth between lines. Thus, it is not only needed the recognition of necessity in industrial line but also the development of automation system arraying ferrule and filling epoxy in the manufacturing process. It is found that the present system development enhances productivity fairly and prevents industrial disaster in the optical connector manufacturing system.

• Korean Journal of Occupational Health Nursing
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• v.6 no.2
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• pp.79-95
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• 1997

The purposes of this study were to develop a job stress measurement tool and to identify the job stress according to the characteristics of worker and work condition at the small and medium-sized plants. Data were collected through face-to-face survey for April-May, 1997. Subjects were 180 workers at 36 small and medium-sized plants located near Seoul. Data were analyzed by item analysis, factor analysis, and ANOVA. The results were as follow : 1, Number of items of job stress measurement were 33 and Cronbach's $\alpha$ was .9262 except 13 items with low values of Cronbach's coefficient. Factor analysis was done in order for construct validity and 8 factors were extracted and cumulative percent of variance was 65.6%. 2. The job stress scores of male, the younger, 2-shift workers, and over-time workers were significantly higher than those of female, the older, 1-shift workers, and 48 hour workers per week. 3. There were no significant difference between job stress scores and the groups by number of worker, and the types of manufacturing. The stress measurement tool is valid and very reliable to measure worker's stress. Furthermore, the job stress managent program for health promotion of the workers at the vulnerable work condition is needed more and more.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.74-80
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• 2007

In manufacturing industry, machining technology for metal cutting processes has been considered traditional and economic dimensions such as production cost, production time and quality of a final product. However, owing to governmental regulations and the change of owner's cognizance, the safety of the workers becomes important in those fields. In this paper, the operation planning system developed as a key component of CAPP(Computer Aided Process Planning) system is introduced for milling operations. The main issue in the system is to determine the cutting conditions in achieving a balanced consideration of productivity and worker's safety. For this reason, the system performs the modification process of standard cutting conditions to satisfy those requirements. Related to machining safety in metal cutting, representative and habitual mistakes that operators perform without considering carefully the characteristic of machine or work piece are described and then the detailed algorithm and functions of the developed system is introduced and discussed.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.55-61
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• 2007

The purpose of this study is to assess the welfare level for shift workers by means of their satisfactions to the jobs in manufacturing environment. As a measurement tool of job satisfaction, we use the JDI(Job Descriptive Index) which can ensure reliability and are widely used. Measurement factors are investigated by means of the duty, payment, promotion, supervisor, co-workers, and general job satisfaction of shift workers. For the application of job satisfaction, 109 workers, 12-hour shift workers in domestic five companies related with manufacturing industry are considered. They treat general facilities in night shift work. The result of this study may be used as a strategic data of welfare policy for improving the welfare level of shift workers.

• Korean Journal of Computational Design and Engineering
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• v.10 no.3
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• pp.199-209
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• 2005

In this paper, a digital simulation model for an automotive assembly line is constructed by adapting a digital manufacturing methodology. Applied methodology is a simulation for a plant level of the assembly production line. The first significance of this methodology is a validation of the production planning based on various scenarios. The second is pre-verification for the new production plan or production method. The third is a visualization of the production process. Several models were implemented and those models were verified. Then, it was possible to find a most efficient production scenario and production method.