• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.5
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• pp.420-427
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• 2008

For simulation of a fin unfolding motion for the various aerodynamic conditions, equations and moments applying to the unfolding fin were modelled. Aerodynamic roll moment consists of the static roll moment and the damping moment, which were obtained through wind tunnel tests and numerical analyses respectively. Panel method was used to compute the roll damping coefficient with deflected fin, whose angle was equivalent to angle of attack due to the deployment motion. Roll damping coefficient is a function of angle of attack, sideslip angle, and deployment angle but not of angular velocity of deployment. Simulation with aerodynamic damping model gave more similar deployment time compared to fin deployment test results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.283-292
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• 2009

Considering an integral equation governing the motion of unfolding fin, an algebraic equation was acquired to get estimated minimum deployment energy required for the successful fin unfolding under the given wind condition. To complete the integration of moment, some approximations had to be introduced particularly to frictional moment and aerodynamic damping for which deployment angular speed of the unfolding fin was modelled as a function of deployment angle only with assumed profile using expected maximum angular speed. Technique for the estimation of the minimum required deployment energy was finalized by introducing the ideal deployment angular speed representing work done by the fin unfolding device alone during fin unfolding and was confirmed by comparing results from simulation with various aerodynamic conditions and profiles of the hinge torque.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.726-736
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• 2012

This paper deals with Spin/Stall Recovery Parachute System from design to ground taxiing stage which would be deployed on the high speed taxi of turbo-prop airplane. In detail design phase, design parameters- riser length, parachute type, size, porosity, parachute canopy filling time, and deployment method- were considered based on the analytical disciplines such as aerodynamics, structures, and stability & control. Before the installation of Spin/Stall Recovery System of turbo-prop airplane, all control functions of this system were validated by the SBTB(System Breakout Test Box) in the laboratory. SBTB was used to confirm if it can detect faults, and simulate the firing of pyrotechnic devices that control the deployment and jettison of it. Once confirmed normal operation, deployment of parachute on the high speed taxiing were performed.

• (The)Study of the Eastern Classic
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• no.70
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• pp.91-117
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• 2018

This paper examines the persuasive style(論說類) proses of Myeonggog(明谷) Choi, seokjeong(崔錫鼎, 1646~1715). He is a disciple of Namguman(南九萬) and Parksechae(朴世采), and is a man who played an active part by political soron(少論) leader in the middle of the Joseon Dynasty. It is also a central figure that links the genealogy of the late Joseon Dynasty, which leads to Namguman(南九萬)-Choiseokjeong(崔錫鼎)-Chotaeeok(趙泰億). He wrote total 14 persuasive style prose. The time of creation is from around 1671 until the end of life. In this paper, the preoses to be analyzed are Sunukron(荀彧論), Bujadaegaron(夫子待賈論) and Muneongyebyeon(文言系辭辨). The reverse idea that reverses the existing discussion is outstanding, and the work which is unique in composition is Sunukron(荀彧論). Bujadaegaron(夫子待賈論) is a work that uses the ryubi(類比) to increase persuasiveness and converts the existing perspective. Muneongyebyeon(文言系辭辨) is a work that attempted to harmonize in the formality of vocabulary, sentence and composition while showing the logical perfection to dismiss the counter-argument's prerequisite. For example, Muneongyebyeon(文言系辭辨) consists of a total of five paragraphs in aspect of composition, each paragraph arranged in good order. In addition, this work presented sequential arguments, used the incremental method which emphasizes the importance of arguments as it moves backward.