• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.81-89
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• 2022

It is necessary to increase the surface hardness and improve the wear resistance and peeling resistance through the surface treatment and performance evaluation of the mold steel. As a result of vacuum heat treatment analysis, residual austenite measurement and surface treatment wear test, retained austenite should be removed by sub-zero treatment, and retained austenite was completely removed by treatment at -196℃. The TiMon film coated on the sub-zero treated STD11 specimen showed the lowest coefficient of friction.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.173-182
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• 2020

Since 2000, Korea has seen a big trend in the market, as the EU tightened regulations on environment due to global warming, high oil prices and aging rural population distribution, strengthening the need for multi-purpose electric moto vehicles for small farmers based on eco-friendly energy. Multi-purpose electric motor vehicles for rural small businesses will be a very innovative means of transportation, not only maintained at a low cost and to reduce greenhouse gases through the activation of eco-friendly energy, but also be a very innovative means of transportation for reducing the labor intensity of the aging farming industry and transporting night work and logistics. In this paper, with the implementation of eco-friendly energy policies, small and medium-sized rural small business owners can easily operate on unpaved roads and well-drawn farming environments, while the intensity of labor can be reduced when transporting crops also can simply replace parts at a low cost in the event of an accident. To propose rural multi-purpose modular electric vehicles, the existing literature is reviewed and 12 modular parts are presented by benchmarking electric vehicles at home and abroad. This paper is thought to be helpful for the research of the industry as well as the design industry of modular electric vehicles.

• Culinary science and hospitality research
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• v.16 no.3
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• pp.130-146
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• 2010

This research examines difference in learning motivation and self-regulated learning according to the general characteristics of the students in hotel and food service related departments at vocational colleges, and subsequently identifies correlation between the two attributes. The research conducted a survey for 300 students in hotel and food service related departments at three vocational colleges in Daegu region, and 267 copies were used for the final analysis. In terms of learning motivation, students in the age between 20 and 24 indicated 'employment after graduation' as the strongest motivation while relatively older students indicated 'joy of learning' as their motivation. It turned out that students who showed strong motivation in terms of 'employment after graduation' and 'fun of college life' acquired more professional certificates. Next, regarding self-regulated learning, female students showed higher ability than male students. Students in higher grade, with older age, and with field practice experience showed more strength in self-regulated learning. Students with higher levels of a cognitive strategy, meta cognition and achievement value acquired more professional certificates. Learning motivation and self-regulated learning showed positive correlation with an exception of 'amotivation' among learning motivations. 'Amotivation' demonstrated negative correlation with all the factors of self-regulated learning ability.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.1
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• pp.1-14
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• 2019

Objectives: There are few studies which reflects of each generation's own features, of the New Middle Age and the Elderly's hearing status and their quality of life even though the population of old age has been weighted as baby boom generation's entering into old age. This study is to identify the effects of the new middle age and the elderly's hearing status on their quality of life and to prepare the customized health policies for their health promotion and quality of life improvement as well as the base line data for hearing enhancement programs. Methods: This study was analyzed using the data of the 7th term of the National Health and Nutrition Survey of the Disease Management headquarters. Out of 8,150 adults over the age of 50 who participated in the hearing test, 3,306 were selected and analyzed. Results: At the result of identifying the correlation of hearing status and the quality of life between the New Middle Age and the Elderly, it was confirmed that hearing loss affects low quality of life. The average of quality of life between the New Middle Age and the Elderly was 0.95 and 0.85 each, resulting in higher quality of life in New Middle Age than in the Elderly. The factors affecting the quality of life of the New Middle Age were the level of the education, household income, the type of health insurance, subjective health status. The factors affecting the quality of life of the Elderly were gender, the type of health insurance, subjective health status. Conclusion: Hearing loss of the New Middle Age and the Elderly affects their low quality of life. Therefore the development and the provision of policy program is needed, so as to maintain and manage hearing through age-specific health education. It is expected that the second half of the New Middle Age's life will be much happier, if not taking the treatment-oriented approach of hearing loss only but strengthening the education needed for the maintenance and the management of healthy hearing at their work place, where 50 and 60 generations' workforce has been increased.

• The Journal of Korean Institute for Practical Engineering Education
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• v.5 no.1
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• pp.73-79
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• 2013

This paper presents several case studies of asian colleges's co-op program for successful operation of KOREATECH IPP(Industry Professional Practice) program. The IPP program is a new educational model that combines academic study and industrial work through university-industry cooperation. The IPP experience will lead the university graduates to improve their employment competencies and will be a key to solve the problems of the labor mismatch between university and industry. We will discuss and analyze the strengths and the weaknesses of the Co-op programs of the Kyoto sangyo university, the Hong Kong polytechnic university and the suranaree university in thailand. Based on these case studies, we summarized several benchmarking points for the successful operation of IPP program.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.1-7
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• 2006

Nowadays, out of other transmission parts, the sleeve is getting more and more important part for exact and smooth shifting from gear ratio change whenever drivers are needed. To exact and smooth shifting when drivers are needed, all the parts connected with gear shifting should be machined exactly and having dimensions designers are intended. Especially, in case of the sleeve that the most important functional part to shift from gear ratio change that drivers are intended, it needs high precision grade and quality in both sides runout and outer dia runout as well as inner spline small dia & large dia. Because it's assembled with the synchro hub spline and shifted directly with the mating cone. So, it should be applied the hear treatment(hereinafter referred to H.T.M.T) to prevent the friction and percussion loss from shifting with mating cone. At this time, the deformation problems are raised from almost H.T.M.T. process and it makes the inferior part.

• Health Policy and Management
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• v.28 no.2
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• pp.162-167
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• 2018

Background: In this research, we conducted an analysis to grasp the relationship between hearing and quality of life and to prepare effective troubleshooting. Methods: In this study, we analyzed using the data of the 6th term of the National Health and Nutrition Survey of the Disease Management Headquarters. And, out of 7,380 people, 3,598 adults over the age of 40 years who participated in the hearing test were selected as final research subjects and analyzed. Results: It was confirmed that the result of the analysis affects the quality of life based on hearing. The quality of life associated with hearing loss was unpleasant, motor ability, anxiety/depression, and everyday life affected in order of self management. And factors having an effect on the quality of life of the study subjects were found to be gender, elderly, unmarried, low hearing, low household income, absence of economic activity, and low teaching standards. Conclusion: The conclusion is that strengthening education for realistic management and prevention rather than treatment for unconditional hearing impairment will overcome low self esteem and loneliness and alleviate any uncomfortable life that people with hearing loss give. It is expected to be possible.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1868-1870
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• 2006

Neural network is used in many fields of control systems, but input-output patterns of a control system are not easy to be obtained and by using as single feedback neural network controller. And also it is difficult to get a satisfied performance when the changes of rapid load and disturbance are applied. To resolve those problems, this paper proposes a new algorithm which is the neural network controller. The new algorithm uses the neural network instead of activation function to control object at the output node. Therefore, control object is composed of neural network controller unifying activation function, and it supplies the error back propagation path to calculate the error at the output node. As a result, the input-output pattern problem of the controller which is resigned by the simple structure of neural network is solved, and real-time learning can be possible in general back propagation algorithm. Application of the new algorithm of neural network controller gives excellent performance for initial and tracking response and it shows the robust performance for rapid load change and disturbance. The proposed control algorithm is implemented on a high speed DSP, TMS320C32, for the speed of 3-phase induction motor. Enhanced performance is shown in the test of the speed control.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.211-216
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• 2016

Al alloys are useful materials having high specific strength and are used in machining of parts having thin-walled structures for weight reduction in aircraft, automobiles, and portable devices. In machining of thin-walled structures, it is difficult to maintain dimensional accuracy because machining deformation occurs because of cutting forces and heat in the cutting zone. Thus, cutting conditions and methods need to be investigated and cutting signals need to be analyzed to diagnose and minimize machining deformation and thereby enhance machining quality. In this study, an investigation on cutting conditions to minimize machining deformation and an analysis on characteristics of cutting signals when machining deformation occurs are conducted. Cutting signals for the process are acquired by using an accelerometer and acoustic emission (AE) sensor. Signal characteristics according to the cutting conditions and the relation between machining deformation and cutting signals are analyzed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.4
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• pp.325-329
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• 2014

This paper proposes a method to predict chatter vibration generated in milling processes and to enhance machining quality and surface finish. Chatter vibration is a common problem in the milling of thin walls and floors. It causes a poor surface finish, or even marks, to appear on the final machined surface. Therefore, an effective method is necessary to predict chatter vibration in machine tools. In this investigation, chatter vibration is measured by an accelerometer, microphone, and Acoustic Emission (AE) sensor in a machining operation. Based on the results of the experiment, a microphone can be applied for the prediction of chatter vibration in milling processes.