• Title/Summary/Keyword: conceptual lightness

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Optimum Design of Bracket for Satellite Antenna (위성안테나 브레켓의 최적설계)

  • Hwang, Tae-Kyung;Lim, O-Kaung;Lee, Jin-Sick;Lee, Jong-Ok
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.451-455
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    • 2003
  • Major concern in modern industry is how to reduce the time and cost for product efficient production. Among many mechanical parts of a satellite, bracket plays an important role to support the load when the satellite is launched to space. so enough strength and stiffness. A designer could add unnecessary material and strength it so as not to fail when it used. But if mechanical part of satellite is over-designed, cost will rise and it also goes against to the aim of lightness. To achieve lightness and enough strength and stiffness, optimization algorithm should be introduced in design process. In this study, conceptual design of bracket is carried out to increase the performance of satellite. Some parameter which could change the weight of this part are selected as design variables. Total weight of bracket is to be minimized while displacement and stress should not exceed limit. Size optimization is done with 3D solid element and PLBA, the RQP algorithm. The weight of 0.262kg of initial model is reduced to 0.241kg after optimization process, so 9.8% of weight reduction is obtained.

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A Study on Conceptual Structural Design for the Composite Wing of A Small Scale WIG Flight Vehicle (소형 WIG선의 복합재 주날개 구조 개념 설계에 관한 연구)

  • Kong, Chang-Duk;Park, Hyun-Bum;Kim, Ju-Il;Kang, Kuk-Jin;Park, Mi-Young
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.179-184
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    • 2005
  • In the present study, conceptual design of the main wing for 20 seats WIG{wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The high stiffness and strength Carbon-Epoxy material was used for the major structure and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, firstly the design load was estimated with maximum flight load, and then flanges of the front and the rear spar from major bending load and the skin structure and the webs of the spars were preliminarily sized using the netting rules and the rule of mixture. In order to investigate the structural safety and stability, stress analysis was performed by Finite Element Codes such as NASTRAN/PA TRAN[6] and NISA II [7]. From the stress analysis results, it was confirmed that the upper skin structure between the front spar and rear spar was very unstable for the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich structure at the upper skin and the web were added. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed. Moreover, in order to fix the wing structure at the fuselage, the insert bolt type structure with six high strength bolts was adopted for easy assembly and removal.

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Development and Application of Tutorial for Conceptual Change on Object Recognition of Scientific Gifted in Elementary School (초등과학 영재의 물체 인식 개념 변화를 위한 튜토리얼의 개발과 적용)

  • Lee, Ji-Won;Kim, Jung-Bok
    • Journal of Korean Elementary Science Education
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    • v.30 no.3
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    • pp.340-352
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    • 2011
  • The purpose of this study was to analyze effects of teaching materials for elementary science gifted conception about object recognition. Elementary science gifted have misconceptions that they can see in lightness. They can not explain how a shadow is made. This paper reports in-depth investigation on elementary science gifted's understanding of object recognition focusing on process of light. A program is developed to elementary science gifted in the subject matter. The tutorial emphasizing the process of light consists of pre-test, worksheet, and post-test. The Tutorial has 4 steps; darkness and light, light on things, light reached eyes, structure of the eyes. Each steps has 2~4 experiments. Through the tutorial, we expect their misconceptions can be changed into scientific conceptions. For the research and analysis, a questionnaire is posed to 39 elementary science gifted at M Elementary School in D Metropolitan City. The first method of product analysis makes a comparative study of pre-test, post-test score, and hake gain each test. As a result, total score of all student was raised. And hake gain of pre-test(II) is 0.6, hake gain of post-test is 0.68. It is Medium gain. Also, elementary science gifted could understand how we see through the tutorial emphasizing process of light. And their misconceptions can be changed into scientific conceptions.

A study on the expression of Nomadics displaying in modern fashion - As the central with the Nomadism of Gilles Delleuze - (현대패션에 나타난 노마드적 표현특성에 관한 연구 - 들뢰즈의 노마디즘을 중심으로 -)

  • Jang, Yoonee;Um, So Hee
    • The Research Journal of the Costume Culture
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    • v.21 no.1
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    • pp.66-80
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    • 2013
  • Nomadism means 'divide share' and 'drift where allocated'. The word to express a variety of modern people without being tied to a fixed time and place, constantly moving to new areas and explore the possibility. The progress of this study, first, to research on the conceptual study of Nomadism through Deleuze's theory of art and to organize Nomadism patterns and design paradigms in modern society. Second is to analyze and investigate cases of Nomadism based on the theoretical background in a way to reinterpret to the contemporary fashion, and to suggest the formative characteristics and inherent expressiveness of Nomadism expressed in modern fashion. Theoretical considerations made through the collection data were select from ready-to-wear women's collections 2005 S/S~2013 S/S presented in 'Style.com'. The results of the analysis of the formative characteristics of Nomadism in the $21^{st}$ century fashion are 'mixed expressions of time space and gender', 'pursuit of diversity through self-dismantling', 'clothing systemization of mobile and deformable' and 'temporary amusement, lightness, an expression of the ride rules'. The inherent expressiveness of Nomadism through these types of figurative representation are 'unbounded fashion', 'multi-center, multi-functional' and 'emotional directivity'. As such, philosophy and artistic trends started Nomadism is harmoniously expressed in terms of the design transcending the boundaries of existing stereotypes.

Structural Design and Analysis for Carbon/Epoxy Composite Wing of A Small Scale WIG Vehicle (소형 위그선의 탄소/에폭시 복합재 주익의 구조 설계 및 해석에 관한 연구)

  • Park, Hyun-Bum;Kang, Kuk-Jin;Kong, Chang-Duk
    • Composites Research
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    • v.19 no.5
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    • pp.12-19
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    • 2006
  • In this paper, conceptual structural design of the main wing for a small scale WIG(Wing in Ground Effect) among high speed ship projects, which will be a high speed maritime transportation system for the next generation in Rep. of Korea, was performed. The Carbon/Epoxy material was selected for the major structure, and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for the present study, firstly the design load was estimated through the critical flight load case study, and then flanges of the front and rear spars from major bending loads and the skin and the spar webs from shear loads were preliminarily sized using the netting rule and the rule of mixture. Stress analysis was performed by a commercial FEA code, NASTRAN. From the stress analysis results for the first designed wing structure, it was confirmed that the upper skin between the front spar and the rear spar was unstable fer the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich type structure at the skin and the web were added. After design modification, the structural safety and stability for the final design feature was confirmed. In addition to this, the insert bolt type structure with eight high strength bolts to fix the wing structure to the fuselage was adopted for easy assembly and removal as well as in consideration of more than 20 years fatigue life.