• Title/Summary/Keyword: science drawing

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Mechanism of Fiber Structure Development in High-Speed In-Line Drawing Process of Poly(ethylene Terephthalate) (II) -Studies on Structure Evolution and Property of Obtained Fibers- (폴리에틸렌테레프탈레이트의 고속 In-Line 연신공정내에서의 섬유형성 메커니즘에 대한 연구 (II) -구조물성분석에 의한 섬유내 고유 고차구조형성기구 해석 -)

  • Hahm, Wan-Gyu;Ito, Hiroshi;Kikutani, Takeshi
    • Proceedings of the Korean Fiber Society Conference
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    • 2007.11a
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    • pp.147-150
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    • 2007
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A cellular automaton model for graph drawing on a hexagonal grid (육각 셀룰러 오토마타를 이용한 그래프 그리기)

  • Ko, Sang-Ki;Han, Yo-Sub
    • Proceedings of the Korean Information Science Society Conference
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    • 2011.06b
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    • pp.485-487
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    • 2011
  • 우리는 그래프 그리기를 위한 셀룰러 오토마타 모델을 제안한다. 셀룰러 오토마타는 간단한 전이 규칙들의 집합을 정의함으로써 비교적 복잡한 자연현상이나 사회현상을 재현해낼 수 있는 특징을 갖고 있다. 우리는 기존에 Eades가 제안했던 하중-기초 그래프 그리기 알고리즘을 기반으로 하여 육각형 격자상에서의 그래프 그리기를 위한 셀룰러 오토마타 모델을 제안한다. 제안된 모델은 기존의 알고리즘에 비해 더 효율적인 연산과정을 거치게 되며 보다 대칭적인 그래프를 그려준다.

A study on the Realtime Update of the Digital-Map by the General Survey Map (일반측량성과도에 의한 수치지도의 수시갱신방법 연구)

  • Lee, Sang-Gil;Kwon, Jay-Hyoun;Jeon, Jae-Han
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.3
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    • pp.19-26
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    • 2007
  • The renewal update of the digital map constructed through NGIS has been conducted for the enhancement of usage, maintenance so that the latest data is guaranteed. The total update has been done every five years for five regions of the country using aerial photographs and satellite images. By launching the third phase of NGIS, the updating plan was changed from total to total or partial update including the real time update scheme. Furthermore, the update period was improved from five to two years and four years for a large and a small city, respectively. Therefore, it is necessary to develope a matching technique which combines various geographic information (such as drawing map, surveying drawing and map) with exact position on the digital map. In this study, we developed a matching algorithm based on central point and suggested a method which uses general surveying drawing for revision/update of the digital map. The general survey is conducted when a civilian development on lands are approved. Thus, the outcome from the survey, which is the general survey drawing, contains the latest various contents such as road, building, water pipe and manhole. A consistent and efficient method using the general survey drawing for near real time update of the digital map by applying the developed matching algorithm is presented.

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Simulation and Experimental Investigation of Reverse Drawing Process for Manufacture of High-Capacity Aluminum Liner (대용량 알루미늄 라이너의 성형을 위한 역 드로잉 공정 해석 및 실험)

  • Lee, Seungyun;Cho, Sungmin;Lee, Sunkyu;Lyu, Geunjun;Kim, Soyoung;Kang, Sunghun
    • Journal of the Korean Institute of Gas
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    • v.20 no.4
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    • pp.78-84
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    • 2016
  • In this work, finite element investigations were carried out to optimize reverse drawing process design for manufacture of high-capacity aluminum liner used in fuel cell vehicle. The tensile tests with aluminum alloy Al6061 annealed at $350^{\circ}C$ were carried out to obtain the flow stresses. In order to estimate more accurate flow stresses after necking, the flow stresses were estimated from the comparison of load vs. displacement curves which were obtained from experimental and simulation results of tensile tests. In case of finite element analyses of reverse drawing processes, it was focused on the effects of process designs such as punch and die designs, blank holding force, drawing ratio and the clearance between the punch and blank holder on the generation of wrinkle and fracture of the blank and partially heated punch. However, it was revealed that experimental results still show the fracture at the end of 2nd drawn cup, although partially heated punch is used. Nevertheless, the drawn cup can be used because the sufficient length of the drawn cup for the next flow forming process and spinning process was obtained.

Effect of Shear Deformation During Drawing on Inhomogeneous Microstructures and Textures in High Purity Copper Wires After Annealing (고순도 구리 선재의 어닐링 후 불균질 미세조직과 집합조직에 미치는 신선 시 전단 변형의 영향)

  • Park, Hyun;Kim, Sang-Hyeok;Kim, Se-Jong;Lee, Hyo-Jong
    • Korean Journal of Metals and Materials
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    • v.56 no.12
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    • pp.861-869
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    • 2018
  • To determine the origin of the inhomogeneous microstructure and texture observed in drawn and annealed high purity copper wires, two kinds of drawing process conditions and their influence was investigated. The regular condition, based on a symmetric die, and a condition designed intentionally to produce an inhomogeneous shear deformation using an asymmetric die were employed. The difference in intensity of <111>-<100> distributed texture between the two wires confirmed that the wire drawn under the asymmetric die condition experienced a higher amount of shear deformation. The extensive shear strain in the wire drawn under the asymmetric die condition gave rise to inhomogeneous primary and secondary recrystallization behavior. After annealing at $200^{\circ}C$, grains with <100> texture, which were larger than the surrounding recrystallized grains, were extensively present on one half circle of the wire drawn under the asymmetric die condition, while larger grains with <100> were sparsely observed around the middle region of the wire drawn under the regular condition. Interestingly, the area where the larger grains with <100> texture existed was identical to the area where the high shear strain occurred during drawing in both wires. During annealing at $400^{\circ}C$, grains with <112> texture started to grow abnormally at the center of both wires as a result of secondary recrystallization. After annealing at $900^{\circ}C$ grains with <112> due to secondary recrystallization occupied the entire region of the wire drawn under the regular condition. On the other hand, in the wire drawn under the asymmetric die condition and then annealed at $900^{\circ}C$, the <100> oriented grains as a result of the normal grain growth of the larger <100> grains which were observed after annealing at $200^{\circ}C$, coexisted with the abnormally grown <112> grains. These results indicate that dynamic recrystallization induced by the shear strain during drawing plays an important role in the inhomogeneity of the microstructure and texture of wires after annealing.

The Preconceptions about Shape, Color and Gravity of the Earth in the Third Grade Students (지구의 모양, 색깔, 중력에 대한 3학년 학생들의 선개념)

  • Kang, In-Suk;Jeong, Jin-Woo;Kim, Yun-Ji
    • Journal of Korean Elementary Science Education
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    • v.27 no.1
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    • pp.31-41
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    • 2008
  • The purpose of this research is to investigate the preconceptions of the Earth for 3rd grade students in elementary school. For this study, We interviewed with 30 students and children responded the questions with drawing the pictures. Through the study, We could find as followings. First, they thought that the shape of Earth is sphere only except one who had double conceptions of sphere and flat. Second, the color of the earth seems to be blue because of sea, but mostly answered, it seems to be green more than brown because of continent. Third, the conceptions of the gravity showed us 43% which is the kinds of scientific conceptions for the Earth.

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