• Journal of Aerospace System Engineering
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• v.18 no.4
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• pp.34-42
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• 2024

This study developed a morphing technology applicable to unmanned aerial vehicles (UAVs) with diverse flight characteristics. Existing morphing technologies require additional mechanisms and driving devices, posing challenges in constructing features such as ribs and spars within the wing structure, leading to structural instability. To address this, we developed a Variable-Camber and Variable-Chord (VCC) morphing flap that could maintains a continuously transforming surface during deformation, altering both camber shape and chord length simultaneously. Furthermore, we conducted design and fabrication of UAV wings incorporating these morphing flaps, ensuring structural stability by developing specialized shapes. Furthermore, structural experiments were conducted to simulate flight loads, followed by actual flight tests to validate performances of both morphing mechanism and wings. Finally, wind tunnel tests were conducted to compare results with aerodynamic analysis, confirming the effective applicability of this morphing technology.

• Korean Security Journal
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• no.51
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• pp.293-313
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• 2017

The purpose of this study is to analyze the changes of regional clusters of national 16 areas on the assembly & demonstration in 2010 and 2015. The results of this study were as follows by using hierarchical cluster analysis. First, the regional clusters on the assembly & demonstration in 2010 were divided into three clusters in the first step: (1) Gwangju, Chungnam, Incheon, Chungbuk, Gyeongbuk, Daegu, Gangwon, Jeju, Daejeon, (2) Jeonnam, Gyeongnam, Busan, Jeonbuk, Ulsan, Gyeonggi, (3) Seoul. Second, the regional clusters on the assembly & demonstration in 2015 were divided into three clusters in the first step: (1) Ulsan, Gangwon, Chungbuk, Chungnam, Incheon, Gyeongbuk, Jeonnam, Gwangju, Jeju, Daegu, Daejeon, (2) Busan, Jeonbuk, Gyeongnam, (3) Seoul, Gyunggi. Third, The regional clusters on the assembly & demonstration were Busan, Jeonbuk, Gyeongnam of 'assembly & demonstration management area(labor related)', and Seoul, Gyeonggi of 'assembly & demonstration frequency areas' in 2015. This suggests that policing policies related to assembly & demonstration can be established and implemented flexibly in consideration of the degree of increase and decrease in assembly & demonstration by districts. Furthermore, it will be helpful to manage assembly & demonstration based on the 'police for human rights'.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.7-13
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• 2002

This paper introduced a new hybrid genetic algorithm, verified its performance, and applied it to the optimization of blade design and pitch control for 30kW pitch-controlled variable-speed horizontal-axis wind turbine system to determine the optimum blade chord and twist distributions that maximize the energy production for a given Weibull wind distribution and the optimum blade pitch angles that maintain constant power output.