• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.37-44
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• 2013

Friction stir welding (FSW) is a solid state joining technique that has expanded rapidly since its development in 1991 and has numerous applications in a wide variety of industries. This paper introduces the basic principles of friction stir welding (FSW) and presents a survey of the latest technologies and applications in the field. The basic principles that are discussed include the terminology, tool/workpiece processes, FSW merits and process variants. In particular, the process variants including the rotation speed and traveling speed are discussed, which include the defect-free zone in an oxygen free copper and Al alloy, respectively. Multiple aspects of the FSW machine are developed, including a horizontal 2D FSW machine and a hybrid complex FSW machine. The latest applications are introduced, with an emphasis on the recent advances in the aerospace, automotive, and IT display industries. Finally, the direction for future research and potential applications are examined.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.505-517
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• 2016

The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD) was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is freestanding on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact loade-time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.

• Journal of Engineering Education Research
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• v.25 no.4
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• pp.35-41
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• 2022

In order to enhance basic competencies for freshmen at engineering college, whose learning ability is gradually declining, a new course was developed to review basic mathematics and physics through a process of collecting opinions from fellow professors. Tests in six fields of math and physics with the same problems showed the correct answer rate rose from 24.8% at the beginning of the semester to 59.0% at the end of the semester after operating the course developed. According to the survey, the students' self-evaluated confidence on the basic competencies in 16 fields of math and physics showed a significant increase. Students with high confidence in basic competencies also received high actual grades. General high school graduates' confidence point in basic competencies improved from 54.7 at the beginning to 75.3 points at the end of the semester, while specialized high school graduates' enhanced from 38.3 to 64.0 which is higher than that of general high school graduates at the beginning of the semester.

• Journal of Engineering Education Research
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• v.25 no.6
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• pp.38-46
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• 2022

In order to improve students' interest, class participation and class comprehension in engineering theory classes, a class applying review games as Jinjinga, Bingo, etc. were designed and developed. Through applying them to three engineering theory subjects, the specific effects of the strategy on students' understanding, interest, participation, and academic achievement were analyzed and the usefulness of each review game strategy was analyzed. Analyzing class data over the past 11 years, there was a clear correlation between performance of the students in the review game and their actual grades, which was found to be greater than the negative effect of absence rate on the test performance or grades. This study also researched students' perceptions compared to other general subjects not applying the review games. The results of a survey of the students who took the review game class showed the usual amount of usual studying hours increased, the burden of examination or the amount of studying hours for preparing the exam was reduced, and the class interest and achievement significantly increased compared to other subjects in the same major.

• 대한공업교육학회지
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• v.33 no.2
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• pp.192-217
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• 2008

This paper investigated the perceived criticalities and patterns of Korean Professional Engineer's competency regarding the working activities of automative product development, manufacturing, etc by using questionnaires responded to the survey which were applied to the automotive professors, experts and professional engineers (vocational parties) by e/mail, etc. This research investigated the following questions: First, what are the characteristic patterns, relevancy and perceived criticalities of Korean Professional Engineer's competencies? Second, What are the ranked priority of the Korean Professional Engineers' competencies? Are there any differency for each item, sub group of job, intelectual criterior of the competencies between relevancy and perceived criticalities according to the types of vocational parties, etc.? Accoring to the results; first, Professor group showed highest points among 3 groups per each item of the competencies by vocational parties Second, Chassis design group ranked top position among the 8 sub groups by vocational parties and, third, Problem Solving Knowledge ranked highest points than any others. Korean Professional Engineers are found to be positioned as key members, leaders and managers on surveying market, product planning, designing product & components, developing component parts, establishing shop with production equipment, managing quality control & material handling, organizing relevant meetings, developing human resources by training and learning, to back up finance with law matters, cooperating with concerned parties to achieve organizational goals, and to coordinate projects. etc, identifying ethical issues and business skills in order to survive and win to be competitive in various kinds of the automotive industry battle fields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.435-445
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• 2018

This study analyzed factors that should be considered in the process of export diversification strategy formulation and priorities of strategies. We reviewed the extant literature and interviewed six experts. Cross-sectional analysis of a literature review and interview results were used to determine the influencing factors of export. The data for this study were collected from a survey of 68 export experts in Automotive Parts enterprises. Data were analyzed using AHP. As a result of the analysis, the order of importance appeared in the order of internal capacity, correlation buyer effect, entry barriers, technology response, and competition environment. The regions with a high overseas level were product differentiation, centralization, and low cost, whereas those with a low level were in the order of low cost, product differentiation, and concentration. It is meaningful to review the alternatives for adoption of the export diversification strategy and establish a strategy appropriate to the situation. It is necessary to establish a customized strategy considering the characteristics of the global region, and not only internal competence but also mutual relationship with local buyers are important.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.139-147
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• 2019

In this paper, we propose to explore ways to create internal motivation to enhance the job disposition of Korean and Chinese employees. In order to achieve this goal, we would like to select parameters that may trigger an increasing number of internal motivations for interest in recent years: perceived organisational support, perceived provider support, and perceived peer support, and to explore the impact on job embeddedness. I would like to find out the effect of job embodiedness on involved beauty. The process also seeks to verify that China and South Korea are different. To verify the research theory of this research, we will use a questionnaire to researchers of automotive companies using VR technology in Gyeonggi-do, Korea and Hadong-seong, China, and conducted a survey. A total of 200 pairs of questionnaires were distributed to the study subjects, 195 of which were retrieved, 191 of which eliminated unfaithful responses were used for the final analysis. The collected data were used for frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, correlation analysis, structural equation analysis. The results of this study, identified through empirical analysis, can be summarized as follows: First, Perceived Organizational Support, Perceived Supervisor Support will have a positive impact on Job Embeddedness. Second, Job Embeddedness will have a positive influence on the Innovative Beehivior. Third, Perceived Organizational Support, Perceived Supervisor Support will have a partial positive effect on Innovative Behavior. Fourth, the formation process and influence of Job Embeddedness of corporate employees in Korea and China are partly different, the report showed.

• Resources Recycling
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• v.20 no.1
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• pp.14-27
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• 2011

In order to review the End-of Life Vehicle(ELV) recycling system and recycling business of dismantlers in Japan, scheme of the automobile recycling law, status of ELV recycling, exports of used cars, ELV marketing business of dismantler and upgrading of used parts net work were studied. On the other hand, field survey in details for dismantling works were conducted at West-Japan Auto Recycling Co.. Although the ELV recycling system has been operating smoothly without any noticeable trouble, recycling business is running under severe circumstance. Exports of used cars have been increasing day by day through worldwide 176 countries. Finally, reuse parts of ELV concerning innovation marketing was discussed.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.175-187
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• 1999

To investigate the risk perception of environmental issues, two consequtive surveys were conducted to environmental professionals using a standardized questionnaire from September to October in 1999. The number of subjects were 72 for the first survey and 68 for the second one. The questionnaire was consisted of items such as the degree of environmental pollution in Korea, risk perception of some issues on human health and ecosystem, and seriousness of the problems in the real situation in Korea. For the degree of environmental pollution in Korea, the average risk rating in the second test (7.4 point) was significantly higher than that in the first test (7.2 point). The risk perception on the general human health and ecosystem, and the seriousness in Korea situation were analyzed in the order of ′air pollution′, ′water pollution′,′soil contamination′,′waste′,′toxic chemical pollutants′,′food contamination′,′ocean contamination′, ′odor pollution′, and ′noise pollution′. Also ′toxic chemical pollutants′ problem was perceived to be the highest risk on general human health or ecosystem, and on present situation in Korea. ′Automotive vehicle exhaust′ problem was perceived to be the most severe environmental problems among specific 30 items. ′Industrial source air pollution′,′toxic air pollutants′, and ′domestic and industrial source pollutants to surface water′ were relatively severe environmental problems comparing to other problems. The pollution issues were classified into four categories by two aspects of perception; risk in general setting and seriousness in Korea situation. If the issues were highly serious in Korea and low risk perception in general setting then it is named "the Korea-specific group". Those that were all high score in two aspects, named "the Common group". Those that were all low in two aspects, named "the Nonsignificant group". And the issues were high risk perception in general setting and low seriousness in Korean situation, named "the Latent group".

• Elastomers and Composites
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• v.52 no.1
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• pp.35-47
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• 2017

A comprehensive survey of the available literature showed that in the last few decades, there has been a growing interest in the use of thermoplastic vulcanizates (TPVs). TPVs are the second largest group of soft thermoplastic elastomers (TPEs) after styrene-based block copolymers, and offer a wide range of potential and proven applications, including in mechanical rubber goods, under-the-hood applications in the automotive field, industrial hose applications, electrical applications, consumer goods, and soft touch applications. Over the last two decades, TPVs have shown a strong and steady market growth (~12% per year). Commercialized TPVs are commonly based on blends of ethylene propylene diene monomer (EPDM) rubber and polypropylene (PP), and to a lesser extent on combinations of butyl or nitrile rubber with PP. EPDM/PP TPVs are characterized by finely dispersed crosslinked EPDM rubber particles (particles size varying between 0.5 and $2.0{\mu}m$) distributed in a continuous thermoplastic PP matrix. If the rubber particles of such a blend are small enough and if they are vulcanized well enough, then the properties of the blend are generally improved. This review article introduces various topics and aspects relevant to EPDM/PP TPVs. The development of TPVs, the use of various types of crosslinking systems and co-agents as crosslinking agents for PP/EPDM blends, the morphology and rheology of TPVs, and their typical end-use applications are also reviewed.