• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.79-80
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• 2003

In existing method, the threshold has determined the points to be used in extrapolation and only pre-peak points were used to find t0. However, to reduce error in using this fitting method, in this study, finding t0is considered the correlation between fitting result and each profile in using iteration method. And the proposed method is compared with the existing method.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.310-317
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• 1999

Acoustic emission(AE) signal has been widely utilized to monitor the interaction at the head/disk interface. In this work the relationship between the AE signal and the state of contact between the slider and the disk is presented. Results of the FFT analyses of the AE signal could be used to better understand the interfacial interaction. Also, it was found that wear particles affect the AE signal. Therefore, the signal can be used to monitor the wear particle presence at the interface.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.718-723
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• 2003

The number of jet aircraft is increasing. The aircraft noise making people near airports nervous have become a serious social problem. The aircraft noise can be classified into two groups; noise being generated at take-off or landing and noise form run-up test on the ground. In this paper, we consider the aircraft noise from run-up test on the pound and we suggest the noise suppression system.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1-1
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• 2009

Recently, the FPD industry has faced the limit in market growth due to lack of new growth engine as a replacement of television. With sluggish market demand deepened by global economic crisis and persistent concern over panel oversupply, growth of the panel market has sharply slowed down, and profitability has been eroded. This also has tremendous effect on related industries including component, material and machine industries, spreading a sense of crisis across the whole FPD industry. Under this circumstance, for the FPD industry to take off once again, all involved in the FPD industry must cooperate and come up with innovative ideas, and identify the driving force to realize turbo-charged growth.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.82-85
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• 2003

This paper proposes a preprocessing method for tracking aircraft's take-off and lading. The method uses accumulative difference image technique for segmenting the object from the background, and obtains the centroid of the object exactly using centroid method. Then the moving object is analyzed and represented with the information such as feature point, velocity, and distance. A simulation result reveals that the proposed algorithm has good performance in segmenting and tracking the aircraft.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.2
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• pp.18-22
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• 2009

In this study, we surveyed the operating status of the Light Sport Aircraft(LSA) in Korea, and reviewed the minimum requirements of the airpark for LSA in other countries. Based on the information, we presented the airpark standards to ensure the safe take-off, landing, and operation of LSA in Korea.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.2
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• pp.68-71
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• 2009

In this paper, we presented the cases of tail strike of KAIRS, which is useful to establish the methods to decrease a risk, aircraft operation viewpoint.

• Korean Journal of Social Welfare Studies
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• v.47 no.4
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• pp.183-216
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• 2016

This study aims to investigate the career development experience of youth in late adolescence who entered a different university after taking a semester off (as known as Bansu in Korean), in depth, applying a phenomenological research method. For the research, this study selected seven adolescents as research participants to reveal the essential meaning of their experience, vividly. The data were analyzed by Giorgi's method to draw components of the experience of research participants. As a result of the research, the career development experience of youth in late adolescence who entered a different university after taking a semester off was systematized into 19 sub-categories and structured into four main categories: "high school years in which academic record was more important than aptitude", "the step away from the dream, being forced to proceed to college", "the time of study to take the exam again, which was an advantage and disadvantage at the same time" and "the wish unfulfilled even with the success of entering a different university." It turned out that the main topic was "the repeated way even after passing the repeat sign." They took the College Scholastic Ability Test (CSAT) once again and came back to the narrow way to enter a prestigious university, but they still compromised the standard made by the older generation. This study has significance for late adolescents' welfare and happiness in that it explored the in-depth meanings of the career development experience of youth who entered a different university by taking the CSAT again after taking a semester off. Lastly, based upon the situation of the increase in the number of students who take the CSAT again, this study suggested better measures for career development during adolescence and the promotion of their quality of life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.68-75
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• 2017

This paper presents the experimental and theoretical results of the dynamic responses of a pendular energy extractor in a two-dimensional wave channel. By adopting a wave maker with varying wave height and period, the dynamic responses of the pendular buoy were experimentally obtained. Furthermore, with the aid of the co-simulation of moving particle analysis and rigid dynamic analysis, the dynamic responses of the pendular system were evaluated. In order to validate the feasibility of the proposed wave power generator, the force tuning of the pendular system with restoring energy was carried out. The results provide proof of concept data for the development and design of a commercial model for horizontal wave power generators in the shoreline area.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.6
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• pp.649-654
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• 2010

A three-dimensional numerical study of the WIG-effect vehicle with a direct-underside-pressurization (DUP) system and a propeller is performed to analyze the aerodynamic forces and moments acting on the vehicle. The computational model includes all the compartments of a WIG-effect vehicle, including a propeller in the middle of the fuselage and an air chamber under the fuselage. The DUP system and propeller help considerably reduce the take-off speed and minimize the effect of the hump drag when the vehicle accelerates to take off on water. The airflow is accelerated by a propeller, and the air then enters the air chamber through a channel in the middle of the fuselage, this air helps increase the lift since the dynamic pressure of air is converted to static pressure. However, the air accelerated by the propeller produces excessive drag and creates yawing moment. It is found that the effect of yawing and rolling moments on static stability is negligible.