• Safety and Health at Work
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• 제3권1호
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• pp.31-42
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• 2012

Objectives: The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods. Methods: The psychological fatigue experienced by the workers was obtained through questionnaire surveys. Meanwhile, muscle activity has been analyzed using surface electromyography (sEMG) measurement. Lower extremities muscles include: erector spinae, tibialis anterior, and gastrocnemius were concurrently measured for more than five hours of standing. Twenty male production workers in a metal stamping company participated as subjects in this study. The subjects were required to undergo questionnaire surveys and sEMG measurement. Results: Results of the questionnaire surveys found that all subjects experienced psychological fatigue due to prolonged standing jobs. Similarly, muscle fatigue has been identified through sEMG measurement. Based on the non-parametric statistical test using the Spearman's rank order correlation, the left erector spinae obtained a moderate positive correlation and statistically significant ($r_s$ = 0.552, p < 0.05) between the results of questionnaire surveys and sEMG measurement. Conclusion: Based on this study, the authors concluded that prolonged standing was contributed to psychological fatigue and to muscle fatigue among the production workers.

• 대한산업공학회지
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• 제2권1호
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• pp.61-78
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• 1976

The purpose of this study is to establish the horizontal and vertical working area which is dependent on measuring value of workers, body in order to make easy and stable working environments, and then to design the size of machines, tools and instruments in production factory because of making the practical production conditions which is the most suitable to human characteristics. But there is necessity that we have to review numeric value of measurement periodically because the size of workers' body is variable according to periodic and social circumstances. The establishment of standard working area after measurement enable us to make the best working conditions and we can design standard working table, optimum size of all machines and tools in production activity. Therefore, we can also acknowledge the importance of studying on human engineering because human engineering is necessary to reduction of fatigue in working, saving workers from industrial accidents, fail-safe system, improvement of productivity with increase in efficiency and etc. Finally, this study informs us that numeric value of measurement is larger than that of Japan, but not than that of America and Germany. So we can establish standard working area which is the most suitable for Korean inherence after measurement of detailed parts for workers' body.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.803-807
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• 2000

This paper deals wi th the establishment of the method of non-contact surface roughness measurement by developed system. One of the most Important factor of determinating quality of a produced manufacture is surface roughness The tendency of manufacturing method is changing from small amount manufactures / high-volume production to large amount manufactures / low volume production, and the study of reducing time for surface roughness measurement has been actively investigated The non-contact surface roughness method by using laser which is different from contact method has been only used to the polished surface, so new surface roughness measurement method was adopted by virtue of Fraunhofer diffraction in the periodic surface for on-the-machine. in this paper, we establish the method of non-contact surface roughness measurement which can reduce measuring time in the periodic surface

• 한국콘텐츠학회논문지
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• 제2권4호
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• pp.76-84
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• 2002

The conventional database evaluation method is carried out by the way in which the person in charge of each specialty database(DB manager) composes the evaluation sheets for corretionㆍrevision on the already-constructed database in a manual method and carries out the measurement and re-education of DB workers based upon it. As a result, that way consumes much time on career information and measurement works about DB workers, causing low time and cost efficiency and lack of systematic management of DB workers, resulting in becoming the hindrance factor of databases quality improvement. This research provides on-line, red-time results of measurements about the efficiency of DB production and DB workers by combining the static measurement with dynamic measurement by DB manager, both of which utilize the System. Therefore, the DB manager can contribute to the improvement of DB quality by determining the continuation of DB production by DB workers or carrying out the re-education of DB workers without being affected by time or spacial constraints.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.157-165
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• 1999

Production and measurement of a super-polished few-ppm-scattering mirror substrate are investigated. In order to improve the surface roughness directly determining scattering, the super-polishing process using Bowl-Feed technique is tried. The surface quality of the super-polished substrate is estimated by the phase-measuring interferometer. For the reliable roughness measurement using the interferometer, data averaging method is applied so that the optimal data averaging condition, 30 phase-data averaging and 20 intensity-data averaging, minimizing the measurement error is experimently searched. Based on the optimal data averaging condition, surface roughness of home-made mirror substrate is measured to be less than $0.5{\AA}$ rms corresponding to 2-ppm total-integrated-scattering.

• 미생물학회지
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• 제28권4호
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• pp.318-323
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• 1990

The bacterial secondary production was measured at 6 sites of Lake Soyang in October, 1989 by $^{3}$H-thymidine incorporation rate. Verfication for the method of bacterial secondary production measurement showed that $^{3}$H-thymidine incorporated into DNA, RNA and protein by average percentage of 38.45, 42.27 and 20.07%, respectively. THe more increased incoporated $^{3}$H-thymidine, the more increasde DNA fraction, but protein fraction was generally low. Incorporation of rate of /usp 3/H-thymidine. $^{3}$H-leucine into protein correlated with protein fraction of incorporated $^{3}$H-thymidine. Conversion factors were calculated as follows; $1.83*10 ^{20}$ cells/moles of thymidine incorporated/hr and 1.69*10$^{22}$ cells/moles of leucine incorporated/hr.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.461-462
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• 2006

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.946-949
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• 2005

This paper deals with the algorithm development that inspects defects such as Bright Defect Dots, Dark Defect Dots, and Line Defect caused by the process of LCD(Liquid Crystal Display). While most of LCD production process is automated, the inspection of LCD panel and its appearance depends on manual process. So, the quality of the inspection is affected by the condition of worker. Especially, the more LCD size increases, the more the worker feels fatigued, which causes the probability of miss judgement. So, the automated inspection is required to manage the consistent quality of the product and reduce the production costs. In this paper, to solve these problems, we developed the imaging processing algorithm to inspect the defects in captured image of LCD. Experimental results reveal that we can recognize various types of defect of LCD with good accuracy and high speed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.379-381
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• 2021

정보통신기술이 점차 발전함에 따라 기존의 생산 시스템에 네트워크 및 컴퓨팅 기술을 적용하여 효율적인 생산 환경을 유지하는 연구가 많이 진행되고 있다. 고전적인 제어 시스템과 달리 이러한 스마트 생산 시스템은 생산 환경에 대한 데이터를 실시간으로 수집하여 통계화하고, 그 변화에 따라 유동적으로 작동할 필요가 있다. 본 논문에서는 네트워크 기반의 센서를 통해 실시간으로 데이터를 수집하고, 환경 변화에 효과적으로 대응할 수 있는 계측 시스템을 제시한다. 또한 이를 스마트팜에 적용하여 외부의 환경 변화에 대처하고 효과적인 생산 환경을 유지할 수 있음을 확인하였다.

• 대한기계학회논문집
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• 제18권5호
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• pp.1347-1354
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• 1994

This paper deals with the experimental research, including measurement and analysis and field survey, on the causes of occurring noise defective gear boxes in hoist production plant in order to reduce the fraction of their occurrence. In this reserch following investigations are performed : measurement and gear-boxes, examination of each machining process of production, measurement and analysis of dimensional accuracy of each part, comparative vibration test with exchanging inaccurate parts. From these investigations, it is found that the machining accuracy of pinion gear tooth thickness is the most sensitive factor of noise problem. By maintaining the tooth thickness error within 0.05 mm tolerance in the gear cutting process, the fraction of noise defective gear-boxes are greatly reduced to less than 2%, where the usual rate of it has been 20-50%.