• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.328-337
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• 2015

Objectives: The purpose of this study is to investigate differences in concentration according to the position at the left or right shoulder within a 30 cm of radius of workers' respirators and provide basic data for the establishment of an industrial health policy. Methods: Personal samples were collected from a total of 65 workers from 27 manufacturing firms in South Gyeongsang-do Province from November 5, 2011 to December 30, 2012 after classifying the laborers into left- and right-side groups. The organic compound samples were collected and analyzed in accordance with the NIOSH Manual of Analytical Methods (NMAM) 1501. Results: In terms of the concentration of organic compounds collected from both left and right shoulders at the position of workers' respirators, isobutyl acetate was the highest with 145 ppm at the left shoulder, followed by ethyl acetate (133.5 ppm) and toluene (38.13 ppm). At the right shoulder, on the contrary, ethyl acetate (149.3 ppm) was the highest, followed by toluene (46.26 ppm), xylene (29.63ppm) and isopropyl alcohol (28.06 ppm). Overall, the right shoulder was higher than the left shoulder in terms of concentrations. Conclusions: For the measurement of the working environment, workers' personal samples should be collected at the place closest to the respirator. In terms of the reduction of error, the attachment of two sample media is expected to reduce errors in exposure assessment.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.425-433
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• 2014

The purpose of the study was to investigate the effect of CAD (Computer Aided Design) based alpine mono-ski bucket design on disabled ski athletes' kinematic characteristics. Two national team ski athletes with LW11 disabilities (Locomotion Winter Classification) category for sit ski participated in both pre and post experiment. Both of the subjects performed 3 trials of carved turn on a ski slope under two conditions. Where, subject "A" performed pre experiment with personal bucket and post experiment with the newly developed CAD based bucket whereas, Subject "B" as control subject performed both pre and post experiment with his personal bucket. For the experiment, 24 Infrared cameras were positioned on the ski slope which covered the path of the ski turn. Also, motion capture suit with reflective markers were worn by both subjects. In the result, decrement in medial/lateral displacement of COM, anterior/posterior displacement of COM, flexion/extension angle of trunk as well as velocity losing rate of COM was observed in subject "A" when using the newly developed CAD based bucket. In contrast, no larger effect on performance was observed when using personal buckets. In conclusion, the findings obtained from the study indicated effectiveness of newly developed CAD based bucket by reducing excessive movement of hip and trunk which is an important factor to perform an effective turn.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.179-189
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• 2001

This study was performed to identify the current status of work environment management and to provide appropriate recommendations for small scale industry with less than 5 workers from September, 2000 to October, 2000 in Seoul city and Gyoung-gi province. The 211 companies were surveyed by checklist included the elements of management of work environment, hazardous chemicals, MSDS, personal protective equipment, and ventilation system. The proportion of metal products manufacturing and printing industries are 25.6 % and 22.3%, respectively. The daily working hours in printing industry is longer than others. The industries that produce potentially hazardous agents, such as noise, dust, metal, organic solvents, radiation and chemical material are pulp, plating, machinery, and printing, respectively. In above industries, only 2.8 % of those recognised and had MSDS. The proportion of companies providing fire extinguishers, safety showers are found to be 13.3 %, 7.1 %, respectively. Only 24.2 % of companies provided personal protective equipment to the workers. The ventilation system was operated in most of companies. But local exhaust ventilation system is provided to 22.3 % of those, also had not been annually inspected. This study showed that the current status of occupational safety and health was not appropriate for workers in small scale industries. It is suggested that annual physical examination have to be performed, MSDS usage must become widespread, and employer and emplyees in small scale industry should be educated for the treatment and storage of hazardous chemicals to improve the occupational safety and health of the working environment. also, regulatory standard has to be applied to local exhaust ventilation system in small scale industry to improve the working condition.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1295-1299
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• 2003

The Mass Flow Controller(MFC) has become crucial in semiconductor manufacturing equipments. It is an important element because the quality and the yield of a semiconductor process are decided by the accurate flow control of gas. Therefore, the demand for the high speed and the highly accurate control of MFCs has been requested. It is hard to find an article of the control algorithm applied to MFCs. But, it is known that commercially available MFCs have PID control algorithms. Particularly, when the system detects the flow by way of heat transfer, MFC control problem contains the time delay and the nonlinearity. In this presentation, MFC control algorithm with the superior performance to the conventional PID algorithm is discussed and the superiority is demonstrated through the experiment. Fuzzy controller was utilized in order to compensate the nonlinearity and the time delay, and the performance is compared with that of a product currently available in the market. The control system, in this presentation, consists of a personal computer, the data acquisition board and the control algorithm carried out by LabWindows/CVI program on the PC. In addition, the method of estimating an actual flow from sensor output containing the time delay and the nonlinearity is presented. In conclusion, according to the result of the experiment, the proposed algorithm shows better accuracy and is faster than the conventional controller.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.273-297
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• 2016

With research findings that the righteous and advanced society relies on the microscopic personal experience related to the justice as well as the perilous reality of 70% of corporate employees in all industrial environment, this study samples employees in the manufacturing and construction industry, both of which take up 40% of all industries, to look into how the awareness of the justice within their organizations influences the organizational commitment through psychological capital and occupational satisfaction; and to understand the beginnings for the macroscopic change. As a result of verifying the interrelationship between the justice and psychological factors, distributive justice and interactive justice are in a positive relationship with the psychological capital while procedural justice shows no influence; the procedural justice and interactive justice are positive with the occupational satisfaction whereas the distributive justice shows no influence. Also psychological capital appears positive with the occupational satisfaction and organizational commitment while occupational satisfaction is positively related to the organizational commitment.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.567-572
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• 2002

The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS ). We can save much efforts and time in adjusting robots to newly defined workcells by using Off-Line Programming System. A proposed visual calibration scheme is based on position-based visual feedback. The visual calibration system is composed of a personal computer, an image processing board, a video monitor, and one camera. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test, and construction of simple silhouette figures. Then, camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection, which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.140-145
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• 2001

The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS). We can save much efforts and time in adjusting robots to newly defined workcells by using Off-Line Programming System. A proposed visual calibration scheme is based on position-based visual feedback. The visual calibration system is composed of a personal computer, an image processing board, a video monitor, and one camera. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test, and construction of simple silhouette figures. Then, camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection, which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.89-99
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• 1999

The automatic design of shell & tube type oil cooler can be used in real industrial environments. Since the automatic design system is intended to be used in small companies, it is designed to be operated well under environments of CAD package in the personal computer. It has adopted GUI in design system, and has employed DCl language. Design parameters to be considered in the design stage of shell and tube type oil cooler are type of oil cooler, outer diameter, thickness, length of tube, tube arrangement, tube pitch, flow rate, inlet and outlet temperature, physical properties, premissive pressure loss on both sides, type of baffle plate, baffle plate cutting ratio, clearance between baffle plate outer diameter and shell inner diameter and clearance between baffle plate holes. As a result, the automatic design system of shell & tube type oil cooler is constructed by the environment of CAD software using LISP. We have built database of design data for various kinds of shell & tube type oil coolers. The automatic design system have been assessed and compared with existing specification of design. Good agreement with Handbook of heat exchanger and design dta of real industrial environments has been found.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.89-99
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• 2017

The purpose of this study is to analyze safety and health managers' perceptual maps on the effective educational contents and its methods of workplace safety and health education. Self-administered survey was successfully conducted to 582 workers who were 339 in manufacturing, 68 in construction, and 175 in service & others by industry classification. Survey sites were recruited based on business size, incidence of occupational accident, and compliance of workplace safety and health education regulation. Questionnaire included personal factors, workplace factors, and needs of safety and health education at work. Male workers were 85.3% and more than 50% were in their 30s and had university education. Overall needs of educational contents and its methods were greater in manufacturing and services than construction. Two dimensional properties of effective educational contents perceived were 'knowledge structure' which divided to safety and health, and 'behavior outcomes' which divided to indirect and direct. Two dimensional properties of educational methods were 'class activity' which divided to experience-based and verbal-based and 'class participation' which divided to passive and active. Effective educational contents and its methods perceived by safety and health managers commonly included the characteristics of direct, case-based, and participation.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.17-27
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• 2020

To identify the relationship between types of employment(regular and non-regular group) and departments classification (administration, product and research group) and the levels of recognition of chemical substances, a total of 117 workers in cosmetics workplaces. Mainly, regular group and research group showed higher recognition of chemical substances (PPE, ventilation, chemical management, hazards in handling chemicals, skin contact) than non-regular group and administration, product group, but In some cases, production and administrative groups were high. Descriptive statistics(SAS ver9.2)was performed. the results of recognition of chemical substances were analyzed the mean and standard deviation by t-test, and anova, (P=0.05). These results cosmetics manufacturing workplaces have normal level of the perception of chemical substances. In most of the employment types, the regular workers showed high recognition, and the working departments showed high recognition in the research and production groups. Therefore, OEM and ODM cosmetics manufacturers regularly identify characteristics and needs of workplaces and workers, and suggest the development of experience and practiced education programs and risk assessment tools that can raise worker awareness.