• Title/Summary/Keyword: R123

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Development of a National R&D Knowledge Map Using the Subject-Object Relation based on Ontology (온톨로지 기반의 주제-객체관계를 이용한 국가 R&D 지식맵 구축)

  • Yang, Myung-Seok;Kang, Nam-Kyu;Kim, Yun-Jeong;Choi, Kwang-Nam;Kim, Young-Kuk
    • Journal of the Korean Society for information Management
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    • v.29 no.4
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    • pp.123-142
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    • 2012
  • To develop an intelligent search engine to help users retrieve information effectively, various methods, such as Semantic Web, have been used, An effective retrieval method of such methods uses ontology technology. In this paper, we built National R&D ontology after analyzing National R&D Information in NTIS and then implemented National R&D Knowledge Map to represent and retrieve information of the relationship between object and subject (project, human information, organization, research result) in R&D Ontology. In the National R&D Knowledge Map, center-node is the object selected by users, node is subject, subject's sub-node is user's favorite query in National R&D ontology after analyzing the relationship between object and subject. When a user selects sub-node, the system displays the results from inference engine after making query by SPARQL in National R&D ontology.

QUATERNIONIC HEISENBERG GROUP

  • Shin, Joonkook;Hong, Sungsook
    • Journal of the Chungcheong Mathematical Society
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    • v.16 no.1
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    • pp.123-135
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    • 2003
  • We shall study the automorphism group of the quaternionic Heisenberg group $\mathcal{H}_7(\mathbb{H})=\mathbb{R}^3{\tilde{\times}}\mathbb{H}$ which is important to investigate an almost Bieberbach group of a 7-dimensinal infra-nilmanifold and show that Aut$$(\mathbb{R}^3{\tilde{\times}}\mathbb{R}^4){\sim_=}Hom(\mathbb{R}^4,\mathbb{R}^3){\rtimes}O(J;2,2)$$.

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Exergy Analysis of Vapor Compression Cycle Driven by Organic Rankine Cycle (유기랭킨사이클로 구동되는 증기압축냉동사이클의 엑서지 해석)

  • Kim, Kyoung Hoon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.12
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    • pp.1137-1145
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    • 2013
  • In this study, exergy analysis of a thermally activated refrigeration cycle, a combined organic Rankine cycle (ORC), and a vapor compression cycle (VCC) were conducted. It is considered that a system uses a low-temperature heat source in the form of sensible heat, such as various renewable energy sources or waste heat from industries, and one of eight working fluids: R143a, R22, R134a, propane, isobutane, butane, R245fa, or R123. The effects of turbine inlet pressure and the working fluid selected on the exergy destructions (anergies) at various system components as well as the COP and exergy efficiency of the system were analyzed and discussed. The results show that the component of the greatest exergy destruction in the system varies sensitively with the turbine inlet pressure and/or working fluid.

Manufacturing technology and R&D status of high temperature superconducting wire (고온초전도선재 제초기술과 개발 동향)

  • Oh, S.S.;Ha, D.W.;Ha, H.S.;Park, C.;Song, K.J.;Ko, R.K.;Kwon, Y.K.;Ryu, K.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.67-73
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    • 2002
  • The development of high performance HTS wire is a key factor for various electrical applications of coils and cables. The purpose of this paper is to review and consider the main manufacturing technologies of HTS wire and its current status. A lot of efforts have been focused on the optimization of PIT parameters for Bi-2223/Ag wire. According to this, long Bi-2223 wires having Ic of 130 A were recently produced and their mass production has been underway in US. The current status performance of Bi-2223 wire is supposed to be used in power transmission cable because of its lower self-field property. Y-123 second generation conductor is extensively being developed throughout the world and many fabrication processes are competed with each other. 30 m-long Y-123 wire with Ic of 0.8 MA/$\textrm{cm}^2$ was recently fabricated using IBAD and PLD techniques in Japan. This result offers promise of scalable processing of practical multi-layer coated conductor.

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Magnetic Properties of $GdBa_2Cu_3O_{7-y}$ Bulk Superconductors Fabricated by a Top-seeded Melt Growth Process (종자 결정 성장법으로 제조된 $GdBa_2Cu_3O_{7-y}$ 벌크 초전도체의 자기적 특성)

  • Kim, K.M.;Park, S.D.;Jun, B.H.;Ko, T.K.;Kim, C.J.
    • Progress in Superconductivity
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    • v.14 no.1
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    • pp.39-44
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    • 2012
  • The fabrications condition and superconducting properties of top-seeded melt growth (TSMG) processed $GdBa_2Cu_3O_{7-y}$ (Gd123) bulk superconductors were studied. Processing parameters (a maximum temperature ($T_{max}$), a temperature for crystal growth ($T_G$) and a cooling rate ($R_G$) through a peritectic temperature ($T_P$) for the fabrication of single grain Gd123 superconductors were optimized. The magnetic levitation forces, trapped magnetic fields, superconducting transition temperature ($T_c$) and critical current density ($J_c$) of the Gd123 bulks superconductors were estimated. Single grain Gd123 bulk superconductors were successfully fabricated at the optimized processing condition. The $T_c$ of a TSMG processed Gd123 sample was 92.5 K and the $J_c$ at 77 K and 0 T was approximately $50kA/cm^2$. The trapped magnetic field contour and magnetic levitation forces were dependent on the top surface morphology of TSMG processed Gd123 samples. The single grain Gd123 samples, field-cooled at 77 K using a Nd-B-Fe permanent magnet with 5.27 kG and 30 mm dia., showed the trapped magnetic field contour of a single grain with a maximum of 4 kG at the sample center. The maximum magnetic levitation forces of the single grain Gd123 sample, field-cooled or zero field-cooled, were 40 N and 107 N, respectively.

SECOND ORDER PARALLEL TENSORS AND RICCI SOLITONS ON (LCS)n-MANIFOLDS

  • Chandra, Soumen;Hui, Shyamal Kumar;Shaikh, Absos Ali
    • Communications of the Korean Mathematical Society
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    • v.30 no.2
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    • pp.123-130
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    • 2015
  • The object of the present paper is to study the second order parallel symmetric tensors and Ricci solitons on $(LCS)_n$-manifolds. We found the conditions of Ricci soliton on $(LCS)_n$-manifolds to be shrinking, steady and expanding respectively.