• Title/Summary/Keyword: Folded antenna

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Optimal Design of Stiffness of Torsion Spring Hinge Considering the Deployment Performance of Large Scale SAR Antenna (전개성능을 고려한 대형 전개형 SAR 안테나의 회전스프링 힌지의 강성 최적설계)

  • Kim, Dong-Yeon;Lim, Jae Hyuk;Jang, Tae-Seong;Cha, Won Ho;Lee, So-Jeong;Oh, Hyun-Ung;Kim, Kyung-Won
    • Journal of Aerospace System Engineering
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    • v.13 no.3
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    • pp.78-86
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    • 2019
  • This paper describes the stiffness optimization of the torsion spring hinge of the large SAR antenna considering the deployment performance. A large SAR antenna is folded in a launch environment and then unfolded when performing a mission in orbit. Under these conditions, it is very important to find the proper stiffness of the torsion spring hinge so that the antenna panels can be deployed with minimal impact in a given time. If the torsion spring stiffness is high, a large impact load at the time of full deployment damages the structure. If it is weak, it cannot guarantee full deployment due to the deployment resistance. A multi-body dynamics analysis model was developed to solve this problem using RecurDyn and the development performance were predicted in terms of: development time, latching force, and torque margin through deployment analysis. In order to find the optimum torsion spring stiffness, the deployment performance was approximated by the response surface method (RSM) and the optimal design was performed to derive the appropriate stiffness value of the rotating springs.

External Morphology of the Asian Ladybird-fly, Degeeria separata, with Scanning Electron Microscope (주사전자현미경을 이용한 무당벌레에 기생하는 무당벌레기생파리(Degeeria separata)의 외부형태적 특징)

  • Youn, Young-Nam;Kim, Nam-Sung;Kim, Ki-Duck;Park, Su-Jin;Seo, Mi-Ja;Chae, Soon-Yong
    • Korean Journal of Agricultural Science
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    • v.27 no.1
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    • pp.20-24
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    • 2000
  • External morphological characteristics of male and female of Degeeria separata, which was endoparasited in adult of the Asian ladybird, were studied by using the scanning electron microscopy (SEM). The antenna of Degeeria separata was consisted of three segment and arista. Aristae were about $750{\mu}m$ length and $30{\mu}m$ in diameter. The surface of antennae was covered with many sensilla. They were long or short, slender or thick, and straight or curved. Each three morphological types of sensilla were observed on the second and third segment of antennae. The mouthpart was sponging type. It was consisted with clypeus, labellum, labium, labrum, and maxillary palp. The labellum is $400{\mu}m$ width and double folded vertically. The leg consist of tarsus, tarsus claw, pulvilli, and empodium.

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