• Title/Summary/Keyword: ECCD

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A Document Classification System Using Modified ECCD and Category Weight for each Document (Modified ECCD 및 문서별 범주 가중치를 이용한 문서 분류 시스템)

  • Han, Chung-Seok;Park, Sang-Yong;Lee, Soo-Won
    • The KIPS Transactions:PartB
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    • v.19B no.4
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    • pp.237-242
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    • 2012
  • Web information service needs a document classification system for efficient management and conveniently searches. Existing document classification systems have a problem of low accuracy in classification, if a few number of feature words is selected in documents or if the number of documents that belong to a specific category is excessively large. To solve this problem, we propose a document classification system using 'Modified ECCD' feature selection method and 'Category Weight for each Document'. Experimental results show that the 'Modified ECCD' feature selection method has higher accuracy in classification than ${\chi}^2$ and the ECCD method. Moreover, combining the 'Category Weight for each Document' feature value and 'Modified ECCD' feature selection method results better accuracy in classification.

Evaluation of ECCD power requirement for neoclassical tearing modes suppression in the CFETR hybrid scenario

  • L.H. He;P.W. Zheng ;T. Yu
    • Nuclear Engineering and Technology
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    • v.55 no.8
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    • pp.2941-2951
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    • 2023
  • The optimal minimum ECCD power is evaluated numerically for completely suppressing the 3/2 and 2/1 NTMs in the CFETR hybrid scenario. For two typical frequencies of ECCD sources launching from two upper launcher (UL) ports, fec = 210 GHz and 240 GHz with O1-mode, UL1: (Ri, Zi) = (8.47, 5.7) m and UL2: (Ri, Zi) = (8.2, 4.5) m, higher frequency of ECCD source launching from the UL2 port is better than that low frequency counterpart from the UL1 port. Using 240 GHz ECCD source launching from the UL2 port, the minimum power required to fully suppress the two NTMs with precise ECCD alignment is 12.4 MW and 16.7 MW, respectively. When good alignment cannot be achieved, the results suggest that the misalignment should not exceed 0.02α, preferably 0.015α, corresponding to 4.4 cm and 3.3 cm. Considering engineering difficulty of high-frequency gyrotron sources, the optimal minimum ECCD power with the 210 GHz source launching from the UL2 port is 17.9 MW and 20.6 MW for completely suppressing the 3/2 and 2/1 NTMs, respectively. In view of this, it is a good choice to select the 210 GHz ECCD source launching from the UL2 port in the short and medium term.

High Frequency Electroporation-Transformation System for Coryneform Bacteria (전기장 충격법에 의한 코리네헝 세균의 고효율 헝질전환)

  • 노갑수;김성준
    • KSBB Journal
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    • v.5 no.3
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    • pp.299-306
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    • 1990
  • Escherkchla coli/Cownebacterium glutamicum shuttle vectors, pECCGl and pECCG2 were constructed by joining a 3.0 kb C. glutamicum cryptic plasmid pCBl and a 3.94 kb E. coli plasmid pACYC177. Using the plasmid pECCGl, various parameters involved in electroporation system including electric field strength, resistance, DNA concentration, cell concentration and growth stage were investigated independently and optimized for the high efficiency transformation of coryneform bacteria. Transformation efficiencies of 106 transformants/$\mu\textrm{g}$ of plasmid DNA were achieved with Corynebacterium glutamicum.

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Analysis of Dielectric Coated Electromagnetically Coupled Coaxial Dipole Array (ECCDA) Antenna (유전체가 입혀진 전자기 결합 동축 다이폴 어레이 안테나의 해석)

  • Koo Sung-Mo;Yiug Woo-Suk;Lee Chang-Won
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.4
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    • pp.317-324
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    • 2004
  • Electromagnetically coupled coaxial dipole (ECCD) array antenna with and without short-ended termination is investigated theoretically. The integral equations are derived for the structure by use of the Fourier transform and mode expansion of radial waveguide. The integrals appearing in the integral equations are evaluated along the branch cut instead of real axis for a faster convergent integral. The effects of slots and dipoles, short-ended termination length, and dielectric coating on the radiation characteristics are presented. Radiation pattern of the structure is also investigated. The results of the present method are compared with those of the commercial EM simulator and good agreement is found.

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