• Transactions on Control, Automation and Systems Engineering
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• v.3 no.4
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• pp.272-282
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• 2001

Uncertainties are the main reasons of deterioration of contour control of industrial articulated robot arm. In this paper, a high-precision contour control method was proposed to overcome some main uncertainties, such as torque saturation, system delay dynamics, interference between robot links, friction, and so on. Firstly, each considered factor of uncertainties was introduced briefly. Then proper realizable objective trajectory generation was presented to avoid torque saturation from objective trajectory. According to the model of industrial articulated robot arm, construction of Gaussian neural network controller with considering system delay dynamic, interference between robot links and friction was explained in detail. Finally, through the experiment and simulation, the effectiveness of proposed method was verified. Furthermore, based on the results it was shown that the Gaussian neural network controller can be also adapted for the various kinds of friction and high-speed motion of industrial articulated robot arm.

• 대한공업교육학회지
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• v.30 no.2
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• pp.33-44
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• 2005

The purpose of this study is to suggest plans to improve the industrial high school through the inquiry of Competency-Based Education(CBE). The suggestions are as followings: (1) Selection and organization of the educational contents of industrial high school must be based on job analysis. (2) Instructional objectives must be defined as a performance objective and enabling objectives. (3) Instruction must be individualized in method, the instructional contents must be organized in the unit of module. (4) Evaluation system must be not knowledge based but performance-based. (5) Physical Environment of work shop must be organized based on facilities, equipments and machines abstracted by job analysis. (6) Competency-Based Teacher Education(CBTE) program is required to train competent teachers in practice.

• Journal of the Korean Society of School Health
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• v.14 no.2
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• pp.177-186
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• 2001

This study was conducted to contribute to the basic data for decisions on environment policy improvement in health promotion, and school sanitation for students in elementary, middle and high schools, by analysing their cognitions and attitudes toward school environmental sanitation. This study was carried out with 1200 male and female students in elementary, middle and high schools in industrial, residential and heavy traffic areas for one month, from July 10 to August 11, 2000. The results of the survey follows. The most serious environmental problems in schools are the toilets, quality of drinking water and the classroom conditions. As for the priority areas for improvement, toilets topped the list followed by the classroom environment, and then by the quality of drinking water. Lack of administrative and financial support, the headmasters' disinterest, lack of interest by the students and parents, lack of awareness among teachers and insufficient effort were cited as the main reasons.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.2
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• pp.117-128
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• 2020

The aim of this study was to examine price sensitivity of industrial products purchased via a group buying system and how industrial products for a group buying system differ from general industrial products, and then identify the major factors in selecting products and the important determinants in purchasing industrial products for school foodservices. The survey was conducted with 250 dietitians (teachers) in Gyeonggi-do Province, who were using industrial products for a group buying system and general industrial products. A paired t-test showed a difference in satisfaction between industrial products for a group buying system and general industrial products by factors, while statistically significant differences were found for red pepper paste, fermented soybean paste and soy sauce in all nine satisfaction factors, including product quality, packaging state, labeling, hygiene, item diversity, specification diversity, price appropriateness and supply. Moreover, analyzing price sensitivity for industrial products for a group buying system, using the PSM method with respect to the issue of high price, showed that the respondents considered that the current unit purchase prices were high for all items investigated. This study suggests that schools would purchase more industrial products for a group buying system, when the pricing of the products are considered with the purchase intention of dietitians (teachers).

• 대한공업교육학회지
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• v.30 no.2
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• pp.3-11
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• 2005

The purpose of this study is to measure the level of the key competencies of industrial high school students and to use it as the basic material so as to improve the key competencies. The subject was 359 industrial high school students(boys: 244, girls: 115) in Seoul, Daejeon, Gwangju, and Busan. The instrument used to measure the key competencies is that developed by Cheol-Young Jeong, which was partly revised with the help of a group of experts. The results of this study showed some of skills were below an average of 3.0, which were writting skill(M=2.85) and speaking skill(M=2.96) in communication skills, logical thinking(M=2.98) in problem solving skills, leadership skill(M=2.88) in interpersonal skills, and self-improvement skill(M=2.96) and the spirit of public service(M=2.93) in self-management and self-improvement skills. But technology skills were above an average of 3.0. And it appeared that technology skills(P=.023) depended on having a certificate or not, and so did communication skills(P=.020) and problem solving skills(P=.034) on the types of a course(employment or entrance into a college). So, to strengthen the key competencies which appeared below an average of 3.0 in this study, not only does the curriculum of industrial high schools need to be reorganized, but systematic strengthening program of key competencies should also be developed.

• Journal of vocational education research
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• v.36 no.2
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• pp.68-94
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• 2017

The purpose of this study is to provide basic data for the development of school education and employment policy by analyzing the differences between image of meister high school students anticipated by industrial HR managers and image actually perceived. For this, semantic differential method developed by Osgood (1957) was selected as the study tool. To find out images of meister high school students, validity of 50 adjectives suggested by Osgood and 21 additional adjectives used in previous studies was reviewed by 10 experts. Final 20 adjectives were selected by excluding adjectives that fail to satisfy validity of contents. Proportional sampling in metropolitan and non-metropolitan areas was done to select 350 final survey samples. A total of 600 surveys were distributed and 230 were returned. Return rate was 38.3%. The results of this study are as follows. First, image of meister high school students anticipated by industrial HR managers showed average score of 2.49, which indicates a positive image. In addition, factor analysis was performed to classify adjectives into groups, and they were divided into three factors including external factor, way of thinking factor, and internal (personality) factor. Second, image of meister high school students currently perceived by industrial HR managers showed average score of 3.24, which indicates a positive image. Third, image of meister high school students currently perceived by industrial HR managers was not as positive as image they anticipate.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.247-250
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• 2001

This paper presents a simple and cost effective circuit topology of single-ended type high frequency quasi-resonant PWM inverter using IGBTs, which can operate under wide soft switching operation range based on ZCS for main power switch as compared with a conventional active voltage-clamped ZVS-PWM high frequency quasi-resonant inverter developed previously. In principle, this new circuit topology can efficiently operate under a constant frequency PWM control-based power regulation scheme. In particular, it is noted that the zero current soft switching (ZCS) commutation can achieve for the main active power switch. On the other hand, the zero voltage soft switching (ZVS) commutation can also achieve for the auxiliary active power switch. The operating principle of this high-frequency Inverter treated here and its power regulation characteristics are illustrated on the basis of the simulation and feasible experimental results.

• Journal of Power Electronics
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• v.2 no.3
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• pp.181-188
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• 2002

The utility interfaced sinewave modulation Inverter for the solar photovoltaic power conditioner with a high frequency transformer is presented for residential applications. As compared with the conventional full-bridge hard switching slnewave PWM inverter with a high frequency link, the simplest single-ended edge-resonant soft switching sinewave inverter with a sinewave duty cycle pulse control scheme is implemented, resulting in size and weight reduction, low cost and high efficiency This paper presents a prototype system of the sinewave zero voltage soft switching sinewave inverter for solar power conditioner, along with its operating principle and unique features. In addition to these, this paper discusses a control implementation to deliver high quality output current. Major design of each component and the power loss analysis under actual power processing is also discussed and evaluated from an experimental point of view A newly developed utility-connected sinewave power conditioning circuit which achieves 92.5% efficiency under 4kW output is demonstrated.

• Journal of the Korea Safety Management & Science
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• v.16 no.2
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• pp.1-9
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• 2014

This study tried to propose plan to prevent human error of railroad driver among human error of railroad worker which takes great share in railroad accident. For this, in order to maintain correlation between the accident actually occurred after the opening of high-speed railroad and experience of accident that did not happened, survey on respondent was analyzed by conducting survey on KTX captain who is working in driving work of high-speed railroad, and instruction management team manager who manages KTX captain and captain. This thesis classified the factors by human factor, job factor, environment factor, organization factor, and established human error management model by comparing and analyzing how each factors have spatial interrelations with a railroad accident. The purpose of this study is to contribute to make safe railroad, and reliable railroad by preventing human error accident by minimizing human error of high-speed railroad drivers, and improving driving workers to cope accurately and fast with irregularities through various institutional improvement, improvement of driving facilities, improvement of operating room environment, and improvement of education system.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.1
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• pp.19-32
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• 2004

This study was conducted to evaluated musculoskeletal subjective symptoms and the degree of stress of industrial workers to present fundamental materials of preventive oriental medicine for improving their health and quality of life. During the medical examination with oriental medicine method, presence of subjective symptoms of musculoskeletal pain, Psychosocial Well-being Index(PWI) and life style were checked by using questionnaire method in 474 industrial workers. The collected data were analyzed with crosstabs, ANOVA and T-test. The results were as follows; 1. In general differences according to musculoskeletal subjective symptoms, education level of high school graduation had significantly higher distribution than that of below middle school or above university graduation in the pain present group. 2. In the musculoskeletal subjective symptoms and the degree of stress, all of Factor1, Factor2. Factor3, Factor4. and PWI had higher score in pain present group than in pain free group and the difference was statistically significant. 3. According to degree of stress and general character of subjects, single and education level of high school graduation had high score in Factor2, Factor3 and PWI. Factor1 and Factor3 was high in income group of low 1.49 million won. Factor2, Factor4, and PWI was high significantly in income group of 1.50 - 2.99 million won. In job type, manufacturing worker group had significantly high score in Factor3. 4. In degree of stress and life style difference, there was significant difference in PWI score in the field of alcohol chinking, smoking, exercise, obesity except sleeping hours. In the present study. as a result, it is found out that musculoskeletal subjective symptoms present group had higher score in psychosocial stress across the fields than symptom-free group and it is recommended that continuous studies on the relationship of job-related musculoskeletal disorders and psychosocial stress should be performed for improvement and prevention of mental and physical health of industrial worke