• 한국수학교육학회지시리즈B:순수및응용수학
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• 제6권1호
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• pp.33-37
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• 1999

We obtain a generalization of Behera and Panda's result on nonlinear scalar case to the vector version.

• 대한수학회보
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• 제53권2호
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• pp.541-550
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• 2016

In this paper, we introduce a quasi-Banach algebra of infinite matrices, which is inverse-closed in the Banach algebra B(${\ell}^2$) of all bounded operators on ${\ell}^2$.

• 대한수학회논문집
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• 제37권4호
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• pp.989-993
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• 2022

In this paper, we prove Pascal's hexagon theorem by elementary tools only. We follow the well-known route to prove the theorem by Bezóut's theorem, explaining all the details in elementary argument. In particular, we prove a toy version of Study's lemma.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.182-185
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• 1996

The purpose of slate estimation in power system is to estimate the best-fit Slate variables from the measurements contaminated by various kind of noise. But because the majority of state estimation modules in EMS lack the convergence characteristics, sometimes the desirable outputs can't be obtained. So, in this paper, the new algorithm using the load now output as initial values in the state estimation calculation is proposed to guarantee the convergence. And if the load now outputs were used as the initial values in the calculation, the change in each step would be small compared to the original method using the flat start point. And the Inverse Lemma is used in the algorithm to calculate the new stale in each iteration step for reducing the calculation time. The proposed algorithm was tested on the IEEE 14, 30, 118 bus systems. Eventually, we were able to verity that the differences between the results obtained by the original method and proposed method were relatively small, and the effectiveness of the proposed algorithm increased when applied to the bigger systems.

• 대한음성학회지:말소리
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• 제62호
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• pp.51-68
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• 2007

Two experiments were conducted to determine the exact locus of the frequency effect in speech production. Experiment 1 addressed the question as to whether the word frequency effect arise from the stage of lemma selection. A picture-word interference task was performed to test the significance of interactions between the effects of target frequency, distractor frequency and semantic relatedness. There was a significant interaction between the distractor frequency and the semantic relatedness and between the target and the distractor frequency. Experiment 2 examined whether the word frequency effect is attributed to the lexeme level which represent phonological information of words. A methodological logic applied to Experiment 2 was the same as that of Experiment 1. There was no significant interaction between the distractor frequency and the phonological relatedness. These results demonstrate that word frequency has influence on the processes involved in selecting a correct lemma corresponding to an activated lexical concept in speech production.

• Korean Journal of Mathematics
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• 제29권4호
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• pp.785-800
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• 2021

In this paper, we obtain a new boundary version of the Schwarz lemma for analytic function. We give sharp upper bounds for |f'(0)| and sharp lower bounds for |f'(c)| with c ∈ ∂D = {z : |z| = 1}. Thus we present some new inequalities for analytic functions. Also, we estimate the modulus of the angular derivative of the function f(z) from below according to the second Taylor coefficients of f about z = 0 and z = z₀ ≠ 0. Thanks to these inequalities, we see the relation between |f'(0)| and 𝕽f(0). Similarly, we see the relation between 𝕽f(0) and |f'(c)| for some c ∈ ∂D. The sharpness of these inequalities is also proved.

• 식물분류학회지
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• 제38권4호
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• pp.477-502
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• 2008

본 연구는 국내산 포아풀속(Poa L.) 17분류군에 대하여, 화서, 소수(spikelet)의 형태, 소화축(rachilla), 포영(glume), 호영(lemma), 내영(palea) 등의 소수의 외부형태학적 형질을 관찰하였다. 소수의 무성아(bulbil) 유무, 화서의 돌기 유무, 호영 기반(callus)의 털 유무 그리고 내영 표면의 털, 유두상 및 자상 돌기의 유무는 아속을 구분하는 형질로, 내영 용골(keel)의 유무, 내영 용골의 털 유무, 제1포영(lower glume) 맥수, 호영 측맥(lateral nerve)의 뚜렷함은 절을 구분하는 형질로, 소화의 개수, 소화축의 유무, 제1포영 맥수, 포영 맥 위의 자상돌기의 유무, 호영 표면의 털과 유두상 및 자상돌기의 유무 등은 종의 식별형질로서 가치를 지니는 것으로 판단되었다. 따라서 한국산 포아풀속 17분류군은 3아속(Ochlopoa, Poa, Stenopoa) 7절(Arenariae, Ochlopoa, Homalopoa, Poa, Pandemos, Tichopoa, Stenopoa)로 정리되었으며, 기존 분류체계에 포함되어 있지 않은 6분류군중 P. ullungdoensis(울릉포아풀), P. takeshimana(섬포아풀), P. matsumurae(가는포아풀)의 3분류군은 Poa아속 Poa절, P. nipponica(큰꾸러미풀), P. radula(좀꾸러미풀)의 2분류군은 Poa아속 Homalopoa절, P. viridula(청포아풀)은 Stenopoa아속 Stenopoa절에 속하였다. 또한 P. nemoralis(선포아풀)은 기존에 Stenopoa아속 Stenopoa절에 속하였지만 Poa아속의 특징을 보여 Poa아속 Poa절에 옮겨져야 한다고 판단되었다. 그리고 1955년 신종으로 발표된 P. ullungdoensis(울릉포아풀)은 최근까지 그 실체가 불분명하였으나, 본 연구에서 그 실체를 확인하였다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제24권3호
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• pp.129-145
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• 2017

In this paper, we establish lower estimates for the modulus of the non-tangential derivative of the holomorphic functionf(z) at the boundary of the unit disc. Also, we shall give an estimate below |f''(b)| according to the first nonzero Taylor coefficient of about two zeros, namely z = 0 and $z_0{\neq}0$.

• 대한수학회지
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• 제39권6호
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• pp.881-898
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• 2002

Our aim in this paper is to introduce a generalization of some notions in homological algebra. We define the concepts of chain U-complex, U-homology, chain (U, U')-map, chain (U, U')-homotopy and $\mu$-functor. We also obtain some interesting results. We use these results to find a generalization of Lambek Lemma, Snake Lemma, Connecting Homomorphism and Exact Triangle.

• 대한수학회보
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• 제50권4호
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• pp.1157-1171
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• 2013

In this paper, by using the $q$-difference analogue of lemma on the logarithmic derivative lemma to re-establish some estimates of Nevanlinna characteristics of $f(qz)$, we deal with the value distribution and uniqueness of certain types of $q$-difference polynomials.