• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.526-530
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• 1996

In this paper, three different types of commercially tools-P20, NC123K and ceramic-have been used to working austempered ductile iron(ADI). In the austempered condition the materials are hard, strong and difficult to machine. Thus, we selected a optimum tool material among three different types of used tools in machining of austempered ductile iron. It was used acoustic emission(AE) to know cutting characteristic for selected tool and flank wear land of the ceramic too. The obtained results are as follows; (1) The ceramic tool among three different types of tools is the best in machining austempered ductile iron. (2) In case of ceramic tool, the amplitude level of AE signal(AErms) is mainly affected bycutting speed in cutting speed in cutting condition and it is proportioned to cutting speed. (3) There have the relationship of direct proportion between the amplitude level of AE signal and flank wear land of the tool. (4) If it find the value of AErms at each cutting speed, the in-process detection to ceramic tool's wear is possible

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.688-696
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• 1995

Cemented carbides, best known for their superior mechanical properties such as high strength, high hardness and high wear resistance, have a wide range of industrial applications including metal working tools, mining tools, and wear resistance components. The cobalt has been used as a binder in the WC-based hard composites due to its outstanding wetting and adhesion characteristics even though its expensiveness. Therefore many studies attempted to find a better substitute for cobalt as binder to decrease production costs. This investigation is a pre-step to study dynamic fracture characteristic evaluation of a WC-Co hardmetal were evaluated by using the instrumented Charpy impact testing procedures. It was found that the dynamic characteristics of used strain amplifier were very important experimental factors to extract valid dynamic fracturing data in WC-Co specimens. It was suggested by showing some experimental examples that when we wished to evaluate dynamic fracture toughness for cemented carbide composites by using the instrumented Charpy impact testing procedure, a careful attention must be given to obtain valid results.

• Fire Science and Engineering
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• v.22 no.4
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• pp.105-114
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• 2008

This study analyzed recruiting system, competence requirement system, promotion system by competence verification, and expert training system in fire officials of the Tokyo Fire Department. The recruiting system is classified into expert and Grade 1, 2, and 3 and all grades are appointed as a fire fighter. According to the competence requirement system, while in office, fire officials who have a certain qualification defined in the recruiting system can change their recruiting classification according to their ability such as Grade $3{\rightarrow}$Grade 2 or 1 or expert, Grade $2{\rightarrow}1$ or expert, or Grade $1{\rightarrow}$expert. The promotion system requires working hard, capability suitable to their grade, and careful verification. Also, a variety of on-site training and qualification systems are provided to reinforce professionalism of staffs and executives.

• STI Policy Review
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• v.1 no.3
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• pp.17-24
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• 2010

Energy consumption is the largest contributing factor for the increase of $CO_2$ emissions and amounts for almost 85% of all emissions. The future energy consumption of Korea is projected to grow exponentially despite its heavy dependence on imported energy that represents 97% of its total energy supply. According to a recent OECD report the carbon emission level of Korea is currently ranked 9th in $CO_2$ emissions, and is growing by almost 3% every year. Against this background, the Korean government introduced the "low carbon green growth" policy in 2008. As the global challenges intensified in the wake of the world economic crisis, Korea has been working hard in raising the visibility of its efforts at the club governance meetings, in particular the G-20 summit. Because of cooperative efforts with major member countries, the G-20 summit agenda has been significantly diversified to include long-term issues such as climate change, development issues, and global health. To achieve an effective green recovery for a new green world economic order, the G-20 summit leaders should concentrate on a strategy of establishing green governance for a global STI cooperation. Korea as the host country is poised to leverage the Seoul G-20 summit to catalyze global efforts toward a new green economic order.

• Journal of the Korea Furniture Society
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• v.25 no.2
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• pp.112-121
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• 2014

The attempt of the contemporary society to overcome the environmental crisis is considered what the whole world is currently interested in. Since value of resources recycling has become emphasized even more, the field of design is, now, working hard to prove how much they are passionate about this eco-friendly design. Of all those activities that the field of design is involving in, a concept called 'upcycling' is receiving the greatest spotlight as a new trend. When it comes to upcycling, you should understand it as a both functional and aesthetic upgraded idea of conventional 'recycling' which would re-use waste resources. With this upcycling, you will have a chance to re-create an object of a new value, and it is a design concept which would consider environmental aspects but also social aspects. Since the year of 2000, the field of furniture design has been pursuing a new design trend which would intensively concern this upcycling concept. In the light of the present circumstances described on the above, this study conducts a case analysis on how upcycling of different materials is applied to furniture design since the year 2000. In doing so, the study improve understanding on furniture design as proposing new ways for you to look at the concerned design. Not only that, it also comes up with ideas and directions for new upcycling furniture design which could be demanded by the environmental industry.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.31.1-31.1
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• 2018

While astronomers are working hard to detect the earliest galaxies and to follow their evolution to redshift z~0, they remain baffled by the present-day dichotomy between disky, star forming (aka late-type) galaxies and quiescent, spheroidal (aka early-type) galaxies. The key is to find galaxies in transition from one class to the other, whose spectra indicate intense recent star formation that has now ended. We have identified thousands of such "post-starburst galaxies" and discovered that they are often the products of late-type galaxy-galaxy mergers. Their current kinematics, stellar populations, and morphologies are consistent with late- to early-type galaxy evolution. I will discuss recent work that suggests new connections between this violent history and the central supermassive black hole. In particular, the molecular gas reservoir of a post-starburst galaxy declines rapidly after the starburst ends and in a manner consistent with feedback from an active nucleus. Furthermore, a star is ~300x more likely to be tidally disrupted by the nucleus of a post-starburst galaxy than in other galaxies. Like the well-known black hole-bulge mass correlation, these surprising links between the properties of a galaxy on kpc scales and its supermassive black hole on pc scales require explanation.

• Korean Journal of Health Education and Promotion
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• v.29 no.5
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• pp.13-26
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• 2012

Objectives: The purpose of this study was to identify the relationship between resilience of migrant workers and their mental health for improving their quality of life and adaptation in Korean society. Methods: Data were collected from March 21 to May 7, 2011. The participants included 488 migrant workers who lived in Busan Metropolitan City or Gyoungnam province. Results: First, heavy working burdens and lack of rests, low wages, poor living environments, low economic status & deficiency of living necessities, hard physical labors, and conflicts with Korean workers had negative effects on mental health. Second, high perceived stress caused by usual 'living difficulties', high 'cutural shock', high feeling of 'social isolation', and high discomfort from 'lack of Korean language proficiency' gave negative effects on migrant worker's mental health. Third, the most important factor on the mental health was the 'cultural shock' among stressors. Even though many stressors existed among migrant workers, these negative effects on mental health were lessened by their high resilience level. Conclusions: This study highlights the importance of migrant workers in Busan, Korea. To improve their mental health, social support including financial supports and educational programs that foster resilience needed.

• Korean Management Science Review
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• v.34 no.2
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• pp.85-101
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• 2017

Currently, the SW industry is the center of digital economy and it is very important industry in terms of market scale and ripple effect. Due to the suffering from poor working environment of the SW industry and the disproportion of manpower supply due to the lack of experienced SW manpower, it is hard to create jobs of high quality for the SW professionals who can be applied to various convergence industries. In this study, we try to analyze the benchmarking cases of successful foreign industrial innovative clusters in order to promote sustainable development direction of SW industry and to create high quality SW jobs. First, the comparison criteria are derived from the viewpoint of creation of high quality SW jobs through an analysis of SW environment by using expert FGI (Focus Group Interview) technique. The critical success factors (CSFs) are derived by comparing and analyzing each industrial cluster cases in terms of SW job creation. This article presents the desirable implications of the cluster of SW industry that can generate SW jobs continuously from the viewpoint of ecosystem environment infrastructure. Through this study, we propose a meaningful direction of SW clusters for job creation, and solve the business inconsistency and suggest ways to increase the sustainability of core competence manpower.

• Knowledge Management Research
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• v.16 no.1
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• pp.21-54
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• 2015

A bunch of management studies have repeatedly revealed that the extent of knowledge sharing across organization contributes significantly to the firm's sustainable competitiveness. However, in reality, it is a hard fact that we must admit that many individuals working in competitive situations always feel reluctant to share knowledge. Especially, positive and negative emotions play an important role in changing individual' s intentions about knowledge sharing and knowledge utilization as well. Intention about knowledge sharing is usually hindered by in-group rivalries. Also employees feel negative in sharing their knowledge with colleagues when they expect to receive little support and recognition in return after doing that. These considerations point out the importance of individual's knowledge sharing and the role of knowledge management in order to assure competitiveness. Considering these facts, the main purpose of this study is to investigate why people is willing or unwilling to share their knowledge with others and utilize the knowledge in the competitive context where potential rivalry is still expected. In answering these research issues, we analyzed 258 valid questionnaires garnered from online community where a number of people has been actively interacting with registered members to share crucial knowledge about sensitive issues. Results revealed that the proposed research issues are adequately solved with significant statistical results.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.84-92
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• 2006

This paper deals with determination of motions of a humanoid robot using genetic algorithm. A humanoid robot has some problems of the structural instability basically. So, we have to consider the stable walking gait in gait planning. Besides, it is important to make the smoothly optimal gait for saving the electric power. A mobile robot has battery to move autonomously. But a humanoid robot needs more electric power in order to drive many joints. So, if movements of walking joint don't maintain optimally, it is hard to sustain the battery power during the working period. Also, if a gait trajectory doesn't have optimal state, the expected lift span of joints tends to be decreased. Also, if a gait trajectory doesn't have optimal state, the expected lift span of joints tends to be decreased. To solve these problems, the genetic algorithm is employed to guarantee the optimal gait trajectory. The fitness functions in a genetic algorithm are introduced to find out optimal trajectory, which enables the robot to have the less reduced jerk of joints and get smooth movement. With these all process accomplished by PC-based program, the optimal solution could be obtained from the simulation. In addition, we discuss the design consideration fur the joint motion and distributed computation of tile humanoid, ISHURO, and suggest its result such as structure of the network and a disturbance observer.