• Title/Summary/Keyword: 종이 접기

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Design of a reconfigurable paper antenna using the origami method (종이접기 방식을 사용한 방사패턴 가변형 종이 안테나 설계)

  • Park, Dong-Kook
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.7
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    • pp.642-646
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    • 2016
  • A wearable antenna made using conductive tape on paper is presented in this paper. The proposed antenna is composed of a half-wavelength conducting dipole strip and a parasitic conducting strip on the A4 copy paper. The antenna is fed at the center of the dipole strip by an SMA connector. The configuration of the proposed antenna changes according to the origami method. Therefore the radiation patterns of the antenna vary according to whether or not the paper is folded. This approach solves the problem that the reception ratio of the signal decreases because of null points in the antenna radiation pattern. The reflection coefficient and the radiation pattern of the proposed antenna at 900 MHz are evaluated using an EM simulation and measurements. It was shown that the proposed paper antenna has reconfigurable characteristics at 900 MHz when utilizing the origami method.

Analysis of Problem Posing Strategy of Mathematics Gifted Students in an Origami Program (종이접기 프로그램에서 수학영재학생들의 문제 만들기 전략 분석)

  • Yim, Geun-Gwang
    • Journal of Gifted/Talented Education
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    • v.20 no.2
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    • pp.461-486
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    • 2010
  • By learning math, constructing math problems helps us to improve analytical thinking ability and have a positive attitude and competency towards math leaning. Especially, gifted students should create math problems under certain circumstances beyond the level of solving given math problems. In this study, I examined the math problems made by the gifted students after the process of raising questions and discussing them for themselves by doing origami. I intended to get suggestions by analyzing of problem posing strategy and method facilitating the thinking of mathematics gifted students in an origami program.

Comparison of Yield, Physico-chemical and Sensory Characteristics for Chicken Surimi Manufactured by Alkaline Adjustment with Different Raw Materials (원료육 종류에 따라 알칼리 조절법으로 제조한 계육 수리미의 수율, 이화학적 및 관능적 특성 비교)

  • Jin, Sang-Keun;Kim, Il-Suk;Kim, Dong-Hoon;Jeong, Ki-Jong;Choi, Yeung-Joon
    • Food Science of Animal Resources
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    • v.26 no.4
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    • pp.431-440
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    • 2006
  • This study was carried out to compare of yield, physico-chemical and sensory characteristics for chicken surimi manufactured by alkaline (pH 11) adjustment with different raw materials. Four experimental groups were surimi with chicken breast (T1) and chicken leg (T2) by spent hen, SF-MDCM (T3) and JY-MDCM (T4). Yield was higher in order of T1>T2>T3>T4 (p<0.05). The yield, physico-chemical and sensory characteristics of T1 were significantly higher than those of other treatments. Especially, $L^*$ and W value, shear force, textural properties, folding test, breaking force, gel strength, breaking $force{\times}deformation$, flavor, color and overall acceptability were higher in T1 but ar value, cooking loss, collagen and myoglobin content of T1 were lower than those of other treatments (p<0.05). Deformation, aroma, juiciness, tenderness were higher but met-myoglobin and yield of T4 were lower than those of T2 and T3 (p<0.05). Crude fat cooking loss and met-myoglobin content were higher in T2 but $b^*$ value, brittleness, hardness, gumminess, chewiness, folding test, breaking $force{\times}deformation$ and aroma of T2 were lower than those of other treatments (p<0.05). pH, collagen and moisture content and br value were higher but crude protein, folding test, $L^*$ and W value, cohesiveness, tenderness of T3 were lower than those of other treatmene (p<0.05). Correlation coefficients (r>0.8) between folding test and other items was positive in crude protein $L^*$ value, shear force and cohesiveness but negative in moisture content (p<0.05).

Emerging Technologies of Elastomers (엘라스토머의 새로운 도약)

  • Jeong, Kwang-Un;Jin, Kwang-Yong;Nah, Chang-Woon;Lee, Myong-Hoon
    • Elastomers and Composites
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    • v.43 no.2
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    • pp.63-71
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    • 2008
  • Up to now, most of researches and practical applications of polymeric elastomers have been focused on rubber, a type of elastomeric materials. Therefore, it has been widely accepted that rubber industry is tire industry. In this review, we would like to illuminate new emerging technologies of elastomers. Among many examples, there are actuators which can transform their mechanical shapes with respect to the surrounding environments. Paper folding (so called "origami" in Japanese) technology can be another good example. Utilizing paper folding technology, three-dimensional (3D) architectures containing multi-functions can be constructed from programmed 2D structures. Elastomer microlens can also be fabricated using lithography technologies combined with chemical reactions.

Folding Analysis of Paper Structure and Estimation of Optimal Collision Conditions for Reversal (종이구조물의 접기해석과 반전을 위한 최적충돌조건의 산정)

  • Gye-Hee Lee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.4
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    • pp.213-220
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    • 2023
  • This paper presents a model simulating the folding process and collision dynamics of "ddakji", a traditional Korean game played using paper tiles (which are also referred to as ddakji). The model uses two A4 sheets as the base materials for ddakji. The folding process involves a series of boundary conditions that transform the wing part of the paper structure into a twisted configuration. A rigid plate boundary condition is also adopted for squeezing, establishing the shape and stress state of the game-ready ddakji through dynamic relaxation analysis. The gaming process analysis involves a forced displacement of the striking ddakji to a predetermined collision position. Collision analysis then follows at a given speed, with the objective of overturning the struck ddakji--a winning condition. A genetic algorithm-based optimization analysis identifies the optimal collision conditions that result in the overturning of the struck ddakji. For efficiency, the collision analysis is divided into two stages, with the second stage carried out only if the first stage predicts a possible overturn. The fitness function for the genetic algorithm during the first stage is the direction cosine of the struck ddakji, whereas in the second stage, it is the inverse of the speed, thus targeting the lowest overall collision speed. Consequently, this analysis provides optimal collision conditions for various compression thicknesses.