• Title/Summary/Keyword: class field

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Fault characteristic analysis of a modularized HTS field coil-based 12 MW class SCSG (모듈화된 계자코일을 가지는 12 MW급 초전도 발전기의 고장 특성 분석)

  • Go, Byeong-Soo;Sung, Hae-Jin;Park, Minwon;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1108-1109
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    • 2015
  • In general, when a high-temperature superconducting (HTS) field coil breaks down, the overall field coils of a superconducting synchronous generator (SCSG) are also stopped working, because of the HTS field coils are connected in series. Therefore, the HTS field coils have to be modularized. The modularized HTS field coil is operated individually. Therefore, even if the HTS field coils are broken-down, the generator still operates under the fault conditions. But the output power and torque of the generator will be affected. This paper deals with the fault characteristics analysis of a 12 MW class SCSG with the modularized HTS field coils when the coils were broken-down. The steady-state and transient state characteristics of the modularized 12 MW class SCSG were analyzed and compared. The fault characteristics analysis results of the 12 MW class superconducting generator for the wind turbines were discussed in detail.

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IMAGINARY BICYCLIC FUNCTION FIELDS WITH THE REAL CYCLIC SUBFIELD OF CLASS NUMBER ONE

  • Jung, Hwan-Yup
    • Bulletin of the Korean Mathematical Society
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    • v.45 no.2
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    • pp.375-384
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    • 2008
  • Let $k={\mathbb{F}}_q(T)$ and ${\mathbb{A}}={\mathbb{F}}_q[T]$. Fix a prime divisor ${\ell}$ q-1. In this paper, we consider a ${\ell}$-cyclic real function field $k(\sqrt[{\ell}]P)$ as a subfield of the imaginary bicyclic function field K = $k(\sqrt[{\ell}]P,\;(\sqrt[{\ell}]{-Q})$, which is a composite field of $k(\sqrt[{\ell}]P)$ wit a ${\ell}$-cyclic totally imaginary function field $k(\sqrt[{\ell}]{-Q})$ of class number one. und give various conditions for the class number of $k(\sqrt[{\ell}]{P})$ to be one by using invariants of the relatively cyclic unramified extensions $K/F_i$ over ${\ell}$-cyclic totally imaginary function field $F_i=k(\sqrt[{\ell}]{-P^iQ})$ for $1{\leq}i{\leq}{\ell}-1$.

HILBERT 2-CLASS FIELD TOWERS OF IMAGINARY QUADRATIC FUNCTION FIELDS

  • Ahn, Jaehyun;Jung, Hwanyup
    • Journal of the Chungcheong Mathematical Society
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    • v.23 no.4
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    • pp.699-704
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    • 2010
  • In this paper, we prove that the Hilbert 2-class field tower of an imaginary quadratic function field $F=k({\sqrt{D})$ is infinite if $r_2({\mathcal{C}}(F))=4$ and exactly one monic irreducible divisor of D is of odd degree, except for one type of $R{\acute{e}}dei$ matrix of F. We also compute the density of such imaginary quadratic function fields F.

FORMULAS OF GALOIS ACTIONS OF SOME CLASS INVARIANTS OVER QUADRATIC NUMBER FIELDS WITH DISCRIMINANT D ≡ 1(mod 12)

  • Jeon, Daeyeol
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.4
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    • pp.799-814
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    • 2009
  • A class invariant is the value of a modular function that generates a ring class field of an imaginary quadratic number field such as the singular moduli of level 1. In this paper, using Shimura Reciprocity Law, we compute the Galois actions of some class invariants from the generalized Weber functions $\mathfrak{g}_0,\mathfrak{g}_1,\mathfrak{g}_2$ and $\mathfrak{g}_3$ over quadratic number fields with discriminant $D{\equiv}1$ (mod 12).

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Field Education Model for Assistant Nurses using Edutech: Flipped Class

  • EunJoo LEE;Yong KIM
    • Fourth Industrial Review
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    • v.3 no.2
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    • pp.19-26
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    • 2023
  • Purpose - This study is to suggest a model of field education in the Assistant Nurses curriculum using edutech and to produce competent Assistant Nurses students reflecting the requirements of various medical fields. This model expects to upgrade the quality of the field education and to provide an Assistant Nurses school with standardized field education tools using edutech. Research design, data, and methodology - Throughout the review of the related thesis, most of them were studied on Assistant Nurses' job satisfaction, conflicts with other jobs in hospitals, and Assistant Nurses' job area in nursing hospitals. To study the current field education for Assistant Nurses students in hospitals, it used interviewing the heads of the hospital nursing department and reflecting on their interview results to develop the model of field education. Result - The field education model with edutech is processed with flipped class. Each area in flipped class is designed by applications and webs which is friendly to both teachers and students. Conclusion - This study presents a simple and easy process of field education using edutech. In the next study, it needs to find the precious results of comparison between students educated by the new model in field education in the Assistant Nurses' curriculum or not.

RELATIVE INTEGRAL BASES OVER A RAY CLASS FIELD

  • Choi, So-Young
    • Bulletin of the Korean Mathematical Society
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    • v.43 no.1
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    • pp.77-80
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    • 2006
  • Let K be a number field, $K_n$ its ray class field with conductor n and L a Galois extension of K containing $K_n$. We prove that $L/K_n$ has a relative integral basis (RIB) under certain simple condition. Also we reduce the problem of the existence of a RIB to a quadratic extension of $K_n$ under some condition.

A Survey on the Consciousness of Middle School Students in Jeju City on the Environmental Education (제주시 지역 중학교 학생들의 환경교육에 대한 의식 조사)

  • Zhin, Kook-Lhim;Oh, Soon-Ja;Koh, Seok-Chan
    • Journal of Environmental Science International
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    • v.17 no.12
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    • pp.1315-1324
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    • 2008
  • This study was investigated on the consciousness of middle school students in Jeju city about the environmental education through questionnaire, in order to understand the actual conditions of environmental education and to find out the solutions about them. Middle 'school students responded that environmental education in school was taken at the class for the special activity or voluntary service, not in regular class and was worked as in the form of the field trip. They generally obtain the knowledge and informations on the environmental problems from mass media such as TV, radio and newspaper than from regular environment class in school. And 36.0% of students perceive that environmental education is needed as a regular class and 31.3% of students perceive that the regular class in school is effective to the environmental education. These results suggest that many students are interested in the regular environment class in school. However, the most of students responded that the regular environment class in school is not worked or is not worked at all, suggesting that the environmental education in middle school is not worked effectively. Most of students prefer to take the environment class in the form of observation or field trip, and they think that observation or field trip is more effective to obtain environmental informations. In conclusion, the special activity such as observation or field trip needs to be supplemented to regular environment class in order to improve the environmental education in middle school more effectively.