• Title/Summary/Keyword: basic structure

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Development of a Basic Structure Design System for Machine Tools by Modular Construction Method (모듈러 구성법을 이용한 공작기계의 기본 구조설계 시스템 개발)

  • 임동휘;김석일
    • Korean Journal of Computational Design and Engineering
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    • v.5 no.2
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    • pp.136-143
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    • 2000
  • The appearance of new machine tools with higher flexibility is in need of a basic structure design system for establishing the systematic and rationalized design and manufacturing procedures. In this study. the basic structure design system for machine tools is realized based on the modular construction method. Machine tools are represented as a whole and modular complex with the directed graph, and all possible structural configurations and codes of machine tools for satisfying the machining requirement are derived from the DNA data and connecting patterns of basic structural elements. Especially the structural configurations of machine tools are visualized by the solid modeling techniques and 3-D graphics techniques.

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Calculation of Joule Heat and Temperature Distribution Generated on the Superconduction Magnet Structure for the KSTAR Operation Scenarios (KSTAR 운전시나리오에 대해 초전도자석 구조물에 발생되는 줄열 및 온도분포 계산)

  • Seungyon Cho;Jeong Woo Sa;Chang Ho Choi;KSTAR Team
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.56-59
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    • 2002
  • Since the KSTAR magnet structure should be maintained at cryogenic temperature of about 4.5 K, even a small amount of heat might be a major cause of the temperature rising of the superconducting magnet structure. The Joule heating by eddy current induced on the magnet structure during the KSTAR operation was found to be a critical parameter for designing the cooling scheme of the magnet structure as well as defining the requirements of the refrigerator for the cryogenic system. Based on the Joule heating calculation, it was revealed that the bulk temperature rising of the magnet coil structure was less than 1 K. The local maximum temperature especially at the inboard leg of the TF coil structure increase as high as about 21 K for the plasma vertical disruption scenario. For the CS coil structure maximum temperature of 8.4 K was obtained from PF fast discharging scenario.

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Electron Crystallography of CaMoO4 Using High Voltage Electron Microscopy

  • Kim, Jin-Gyu;Choi, Joo-Hyoung;Jeong, Jong-Man;Kim, Young-Min;Suh, Il-Hwan;Kim, Jong-Pil;Kim, Youn-Joong
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.391-396
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    • 2007
  • The three-dimensional structure of an inorganic crystal, CaMoO4 (space group I 41/a, a = 5.198(69) A and c = 11.458(41) A), was determined by electron crystallography utilizing a high voltage electron microscope. An initial structure of CaMoO4 was determined with 3-D electron diffraction patterns. This structure was refined by crystallographic image processing of high resolution TEM images. X-ray crystallography of the same material was performed to evaluate the accuracy of the TEM structure determination. The cell parameters of CaMoO4 determined by electron crystallography coincide with the X-ray crystallography result to within 0.033-0.040 A, while the atomic coordinates were determined to within 0.072 A.

Modeling of the triangle optimum shape in the surface of an Aluminum dome structure (알루미늄 돔 구조물에서 표면의 삼각형 최적 형상 모델링)

  • 이성철;조종두
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.647-650
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    • 1997
  • A complete dome structure is based on a basic dome modeling, and the basic dome modeling affects safety of the dome structure. In other to save the manufacture expenses, an optimum shape modeling of a dome structure is necessary work of before manufacture of the dome. In this study, modeling of the triangle optimum shape in the surface of an aluminum dome is more focused to optimize shape of the dome and save manufacture expenses. After being made the systematic procedure of the basic modeling, the programming work of the procedure is performed. The program is made by C language, and the trust of the program is proved by comparison between output data of the program and basic modeling in PATRAN.

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Airframe Durability Certification for Export Basic Trainer (수출형 기본 훈련기에 대한 기체구조물 내구성 입증)

  • Park, Taegyu;Park, Jeongkyu;Moon, Changoh
    • Journal of Aerospace System Engineering
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    • v.9 no.2
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    • pp.19-24
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    • 2015
  • Export basic trainer was designed to add armed configuration required by customer. Design configuration of main wing was changed to satisfy changed internal load caused by armed configuration. It was verified that design changed main wing airframe of export basic trainer satisfy the requirement through the structural detail analysis, structural ground test and flight test. This paper presents the durability test procensure and test result for the main wing of export basic trainer.

DIRECT SUM FOR BASIC COHOMOLOGY OF CODIMENSION FOUR TAUT RIEMANNIAN FOLIATION

  • Zhou, Jiuru
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.6
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    • pp.1501-1509
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    • 2020
  • We discuss the decomposition of degree two basic cohomology for codimension four taut Riemannian foliation according to the holonomy invariant transversal almost complex structure J, and show that J is C pure and full. In addition, we obtain an estimate of the dimension of basic J-anti-invariant subgroup. These are the foliated version for the corresponding results of T. Draghici et al. [3].

Algebraic Structure for the Recognition of Korean Characters (한글 문자의 인식을 위한 대수적 구조)

  • Lee, Joo-K.;Choo, Hoon
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.12 no.2
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    • pp.11-17
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    • 1975
  • The paper examined the character structure as a basic study for the recognition of Korean characters. In view of concave structure, line structure and node relationship of character graph, the algebraic structure of the basic Korean characters is are analized. Also, the degree of complexities in their character structure is discussed and classififed. Futhermore, by describing the fact that some equivalence relations are existed between the 10 vowels of rotational transformation group by Affine transformation of one element into another, it could be pointed out that the geometrical properting in addition to the topological properties are very important for the recognition of Korean characters.

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Calculation of Joule heating and temperature distribution generated in the KSTAR superconducting magnet structure

  • Seungyon Cho;Park, Chang-Ho;Sa, Jeong-Woo
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.78-83
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    • 2002
  • Since the KSTAR superconducting magnet structure should be maintained at a cryogenic temperature of about 4 K, even a small amount of heat might be a major cause of the temperature rise of the structure. The Joule heating by eddy currents induced in the magnet structure during the KSTAR operation was found to be a critical parameter for designing the cooling scheme of the magnet structure as well as defining the requirements of the refrigerator for the cryogenic system. Based on the Joule heating calculation, it was revealed that the bulk temperature rise of the magnet coil structure was less than 1 K. The local maximum temperature especially at the inboard leg of the TF coil structure increased as high as about 21 K for the plasma vertical disruption scenario. For the CS coil structure, the maximum temperature was obtained from the PF fast discharging scenario. This means that the vertical disruption and PF fast discharging scenarios are the major scenarios for the design of TF and CS coil structures, respectively. For the reference scenario, the location of maximum temperature spot changes according to the transient current variation of each PF coil.

Recent advances of 17O NMR spectroscopy

  • Lin, Yuxi;Kim, Hak Nam;Lee, Young-Ho
    • Journal of the Korean Magnetic Resonance Society
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    • v.23 no.2
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    • pp.56-60
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    • 2019
  • Study on the structure and dynamics of molecules at the atomic level is of great significance for understanding their function and stability as well as roles for various chemico-physical and biological processes. $^{17}O$ NMR spectroscopy has appeared as an elegant technique for investigating of the physicochemical and structural properties of oxygen-containing compounds such as metal organic frameworks and nanosized oxides. This method has drawn much attention as it provides unique insights into the properties of targets based on atomistic information of local oxygen environments which is otherwise difficult to obtain using other methods. In this mini review, we introduce and discuss the recent study and developments of $^{17}O$ NMR techniques which are tailored for the investigation on the structure and dynamics of water and inorganic materials.