• 대한수학회지
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• 제56권4호
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• pp.869-915
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• 2019

Let H be a Krull monoid with class group G such that every class contains a prime divisor. Then every nonunit $a{\in}H$ can be written as a finite product of irreducible elements. If $a=u_1{\cdot}\;{\ldots}\;{\cdot}u_k$ with irreducibles $u_1,{\ldots},u_k{\in}H$, then k is called the length of the factorization and the set L(a) of all possible k is the set of lengths of a. It is well-known that the system ${\mathcal{L}}(H)=\{{\mathcal{L}}(a){\mid}a{\in}H\}$ depends only on the class group G. We study the inverse question asking whether the system ${\mathcal{L}}(H)$ is characteristic for the class group. Let H' be a further Krull monoid with class group G' such that every class contains a prime divisor and suppose that ${\mathcal{L}}(H)={\mathcal{L}}(H^{\prime})$. We show that, if one of the groups G and G' is finite and has rank at most two, then G and G' are isomorphic (apart from two well-known exceptions).

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.13-15
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• 2006

다층퍼셉트론을 패턴인식 문제에 적용하는 경우 대부분 하나의 클래스 당 하나의 출력노드를 할당한다. 이 논문에서는 class 당 출력노드 수를 증가시키는 경우에 다층퍼셉트론의 성능이 향상되는 지 고립단어 인식 문제의 시뮬레이션을 통하여 고찰하였다. 시뮬레이션 결과 출력노드 수가 하나인 경우보다 증가시킨 경우 더 나은 성능을 얻었다.

• 대한수학회보
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• 제36권4호
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• pp.683-691
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• 1999

It has long been a question which homology class is represented by an embedded 2-sphere in a smooth 4-manifold. In this article we study the adjunction inequality, one of main results of Seiberg-Witten theory in smooth 4-manifolds, for an embedded 2-sphere. As a result, we give a criterion which homology class cannot be represented by an embedded 2-sphere in some cases.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.13-16
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• 2000

This paper presents a simple class-D stereo amplifier using 3-phase full bridge circuit configurations which is controlled by a new current control switching method. Although this class-D amplifier has an only one current control loop with the proposed switching method, a good performance can be obtained. In this paper, a strategy for driving stereo signal amplifier with 3-phase full bridge is discussed. With the experimental results, usefulness of the proposed amplifier is confirmed.

• 대한수학회지
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• 제33권1호
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• pp.121-136
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• 1996

Met $\tilde{M} = (\tilde{M}, \tilde{J}, <>)$ be an almost Hermitian manifold and M a submanifold of $\tilde{M}$. According to the behavior of the tangent bundle TM with respect to the action of $\tilde{J}$, we have two typical classes of submanifolds. One of them is the class of almost complex submanifolds and another is the class of totally real submanifolds. In 1990, B. Y. Chen [4], [5] introduced the concept of the class of slant submanifolds which involve the above two classes. He used the Wirtinger angle to measure the behavior of TM with respect to the action of $\tilde{J}$.

• 전자공학회논문지B
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• 제31B권8호
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• pp.47-56
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• 1994

The dynamic feedback is well-known to be much more powerful tool in control than the static one. This paper deals with the dynamic feedback linearization of the nonlinear systems which are not (static) feedback linearizable. The dynamic feedback linearization problem is however too difficult to solve at momemt. Thus we introduce a restricted class of the dynamic feedback (pure integrators followed by the static feedback) which is often used to study the problems using dynamic feedback and obtain the necessary and sufficient conditions of the linearization problem using this class of the dynamic feedback.

• 충청수학회지
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• 제25권1호
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• pp.91-95
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• 2012

In this paper, we show how to construct the first layer $k^{\alpha}_{1}$ of anti-cyclotomic ${\mathbb{{Z}}}_{3}$-extension of imaginary quadratic fields $k(=\;{\mathbb{{Q}}}(\sqrt{-d}))$ when the Sylow subgroup of class group of k is 3-elementary, and give an example. This example is different from the one we obtained before in the sense that when we write $k^{\alpha}_{1}\;=\;k({\eta}),{\eta}$ is obtained from non-units of ${\mathbb{{Q}}}({\sqrt{3d}})$.

• 산업공학
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• 제8권3호
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• pp.11-23
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• 1995

During the past few years, the productivity has been considered as one of the most important aims in developing softwares. Many practitioners and theorists are trying reuse ready made codes to increase the productivity of software development and the quality of their products. This paper introduces our experiences in developing a highly reusable class library and its reusing environment for building a database interface application. And the concepts, Structured Multi-Library and Dual Views of Class Inheritance, are also suggested, which consist our main conceptual framework in our work. Details in implementation are discussed in brief at the end.

• 대한수학회보
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• 제58권6호
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• pp.1463-1481
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• 2021

Divisibility properties of harmonic numbers by a prime number p have been a recurrent topic. However, finding the exact p-adic orders of them is not easy. Using class numbers of number fields and Bernoulli numbers, we compute the exact p-adic orders of harmonic type sums. Moreover, we obtain an asymptotic formula for generalized harmonic numbers whose p-adic orders are exactly one.

• 대한화학회지
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• 제50권6호
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• pp.506-514
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• 2006

연구는 교실 밖 화학체험학습 프로그램의 적용이 중학생들의 과학 탐구 능력과 과학 관련 태도에 미치는 영향을 알아보는 것이다. 교실 밖 화학체험학습 프로그램은 ‘재미있는 교실 밖 화학, ‘신나는 과학수업'을 위해 개발된 것으로 자연환경에 부합되는 화학체험 제재를 선정하여 자연에서 실험 소재를 구하고 일상생활 속에서 경험할 수 있는 자연친화적 화학실험으로 구성되었다. 교실 밖 화학체험학습 프로그램은 전일제 계발활동을 통하여 교실과 실험실을 벗어난 자연환경에서 적용하였다. D중학교 3학년 과학반 학생들을 대상으로 실험 집단과 비교 집단으로 나누어 실험 집단은 교실 밖 화학체험학습 프로그램에 참가시키고 비교 집단은 전통적 수업방식을 따랐다. 두 집단 사이의 과학 탐구 능력과 과학 관련 태도의 변화를 비교·분석하고 교실 밖 화학체험학습 프로그램에 대한 학생들의 반응을 알아보았다. 그 결과, 교실 밖 자연친화적 화학실험은 중학생들의 과학 탐구 능력과 과학 관련 태도를 향상시켰다. 또한 학생들의 70% 이상이 교실 밖 화학체험학습 프로그램에 긍정적인 반응을 보였으며 과학에 대한 관심과 흥미, 자발적 참여도가 높아졌다.