• 호남수학학술지
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• 제40권3호
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• pp.591-600
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• 2018

In [4] Miyazaki and Motegi constructed one family of knots in $S^3$ which admits Dehn surgery producing a Seifert-fibered space over $S^2$ with four exceptional fibers. On the other hand, in [3] using doubly hyper Seifert twisted torus knots, the author constructed six families of knots in $S^3$ which admit Dehn surgery yielding a Seifert-fibered space over $S^2$ with four exceptional fibers. It is questioned in [3] whether or not the family of the knots constructed in [4] belongs to one of the six families of the knots in [3]. In this paper, we give the positive answer for this question.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (1)
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• pp.1-3
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• 2004

이 논문에서는 기존의 계층 링을 수정한 Torus Ring을 제안한다. Torus Ring은 계층 링과 완전히 동일한 복잡도를 가지면서도 지역 링간의 연결 방법만을 변경한 형태의 상호 연결 망이다. 이 연결 망은 역방향 인접 링에 대한 요청에서 흡수의 이득을 봉으로써 평균 흥 수를 감소시킨다. 또한 접근의 지역성을 고려하지 않은 균등분포의 가정 하에서도 평균 흡수의 기대 값에서 계층 링과 동일한 값을 가지며, 실제 병렬 프로그램이 수행되는 환경에서는 인접 링에 대한 통신 비율이 증가할 가능성이 크기 때문에 더 큰 흡수의 이익을 기대할 수 있다. 실험 결과 상호 연결 망의 요청과 응답의 지연 시간 단축되었으며, 이러한 응답 지연 시간의 단축이 수행 시간을 최대 7%까지 감소시키는 결과를 가져 왔다.

• 천문학회보
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• 제44권1호
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• pp.83.2-83.2
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• 2019

We study the stability of the magnetic structure in active region (AR) 12371 producing an M6.5 flare on June 22 2015. We first perform a nonlinear force-free fields (NLFFFs) extrapolation to derive three-dimensional (3D) magnetic fields based on time series of observed photospheric magnetic fields. The NLFFFs well describe an observed sigmoidal structure with the shape of a double arc magnetic configuration. Next, we examine three possible instabilities (kink, torus, and double arc) to investigate how the M6.5 flare is triggered in the double arc loops. Consequently, the double arc loops are stable against kink and torus instabilities, but possibly unstable against the double arc instability before the flare occurrence. Finally, we discuss a probable scenario for the M6.5 flare.

• ETRI Journal
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• 제43권1호
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• pp.64-73
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• 2021

Two-dimensional torus network nodes are typically interconnected using XY routing algorithm for transmitting a packet from a source node to a destination node. In XY routing, if all the paths are used efficiently, the throughput and latency can be improved. In this paper, to utilize all the paths efficiently, we propose a novel binary optical routing algorithm (BORA) to improve the throughput and latency. The throughput is calculated according to the injection rate and number of packets received at the destination. The XY routing algorithm and proposed BORA are implemented using objective modular network testbed in C++ simulation software and the results are analyzed and compared. In this paper, the simulation results show that the network latency reduces to 50% while using the proposed algorithm; moreover, the throughput is also improved.

• 대한수학회보
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• 제59권6호
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• pp.1409-1422
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• 2022

A 3-fold quotient terminal singularity is of the type $\frac{1}{r}(b,1,-1)$ with gcd(r, b) = 1. In [6], it is proved that the economic resolution of a 3-fold terminal quotient singularity is isomorphic to a distinguished component of a moduli space 𝓜_𝜃 of 𝜃-stable G-constellations for a suitable 𝜃. This paper proves that each connected component of the moduli space 𝓜_𝜃 has a torus fixed point and classifies all torus fixed points on 𝓜_𝜃. By product, we show that for $\frac{1}{2k+1}(k+1,1,-1)$ case the moduli space 𝓜_𝜃 is irreducible.

• 천문학회보
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• 제44권2호
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• pp.41.1-41.1
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• 2019

The stability analysis of coronal magnetic structures is important for studying the initiation of solar flares and eruptions. In order to understand the flare onset process, we first reconstructed the 3D coronal magnetic structures of active region 12371 with an M6.5 flare using a nonlinear force-free field (NLFFF) model based on vector magnetic fields. The NLFFFs successfully produce the observed sigmoidal structure which is composed of two branches of sheared arcade loops. The stability analysis were examined for three representative MHD instabilities: the kink, the torus, and the double arc instabilities. Our stability analysis shows that the two branches of sheared arcade loops are quite stable against the kink and torus instabilities, but unstable against the double arc instability before the flare occurrence. Finally, we discuss a probable onset process of the M6.5 flare.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2008년도 춘계학술발표대회
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• pp.573-576
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• 2008

본 논문은 분지수가 상수인 토러스를 피터슨-토러스 네트워크에 임베딩 가능함을 보인다. 토러스 T(5m, 2n)는 PT(m, n)에 연장율 5, 밀집율 5 그리고 확장율 1에 임베딩 가능함을 보였다. 추가로 토러스를 PT에 평균 연장율 3이하에 임베딩 가능함을 보였다. 널리 알려진 토러스 네트워크를 연장율과 밀집율을 5이하에 PT에 임베딩 함으로써 웜홀 라우팅 방식과 store-and-forward 방식 모두에서 임베딩 알고리즘이 사용 가능하고, 일대일 임베딩을 함으로써 시뮬레이션시 프로세서 작업 처리량을 최소화 하였다.

• 대한수학회논문집
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• 제19권1호
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• pp.155-158
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• 2004

We give a certain uniqueness properties for the fiber of the Hopf fibration on lens spaces.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2007년도 제33회 하계학술대회 초록집
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• pp.176-176
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• 2007

• 대한수학회논문집
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• 제11권1호
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• pp.201-207
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• 1996

If a torus has $L^p$-bounded second fundamental form then it is included in the lower part of the moduli space. That is, its conformal class is bounded.