• Fisheries and Aquatic Sciences
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• 제5권3호
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• pp.156-164
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• 2002

Enteromorpha prolifera of the isomorphic diploid sporophyte and the haploid gametophyte generations inhabit rocks, tidal flats and tidal pools in the middle parts of intertidal zones. In this experiment, their thalli were observed by bare eyes from October and experienced $74\pm16.5cm$ maximum growth the following March and April. The rate of occurrence of the thalli per month was highest in March, while their biomass peaked at $1,464\pm41.5 g/m^2$ in Jangheung in April. Genetic similarity was investigated samples of E. prolifera collected from Muan, Wando, Jangheung, Yosu and Jinhae, at the south coast of Korea. Random amplified polymorphic DNA (RAPD) markers were used. For the RAPD analysis, 3 ng of the DNA extracted from the thalli using he phenol/chloroform method was amplified by PCR with a 25 {\mu}L$ reaction solution, arbitrary primers and 36 cycles. Among the 60 primers used, 31 yielded products, most of which showed diverse electrophoresis patterns. Similarities among the groups compared ranged from 0.37 to 0.58. We conclude that the use of RAPD analysis is appropriate to characterize the genetic variability of this commercial species along its geographical distribution.

• ALGAE
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• 제21권1호
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• pp.15-48
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• 2006

The genus Martensia (Delesseriaceae, Rhodophyta) is characterized by thalli composed of one to several blades that consist of proximal membranous sections and distal latticework. Nerves or veins are absent in the membranous sections. The life cycle of Martensia is accomplished by isomorphic alternation of generations. The gametophytes of Martensia are dioecious, and the male and female gametangial plants are morphologically similar. The type species of Martensia is M. elegans Hering. In this study, nine species were confirmed to occur in the subtidal regions of Jeju Island, Korea: M. albida sp. nov., M. australis Harvey, M. bibarii Y. Lee, M. elegans Hering, M. flammifolia sp. nov, M. fragilis Harvey, M. jejuensis Y. Lee, M. palmata Y. Lee, and M. projecta Y. Lee. Three of these, M. australis, M. fragilis, and M. elegans, are new records in the flora of Korea. The results of molecular analyses of the internal transcribed spacer (ITS) 1 region in the nrDNA showed that M. elegans is identical to M. australis, and M. fragilis coincides with M. bibarii. It may be a less effective tool for the species discrimination in Martensia.

• Journal of applied mathematics & informatics
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• 제13권1_2호
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• pp.413-424
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• 2003

L. H Encinas, A. J. Menezes and J. M. Masque in [3] proposed a classification of isomorphism classes of hyperelliptic curve of genus 2 over finite fields with characteristic different from 2 and 5. Y. Choie and D. Yun in [2] obtained the number of isomorphic classes of hyperelliptic curves of genus 2 over $F_{2-}$ using direct counting method. We have obtained isomorphism classes of hyperelliptic curves of genus 2 over $F_{2n}$ for odd n, represented by an equation of the form $y^2$ + $a_{5}$ y = $x^{5}$ + $a_{8}$ x + $a_{10}$ ( $a_{5}$ $\neq$0) [1]. In this paper we characterize hyperelliptic curves of genus 2 over $F_{2n}$ for even n, represented by an equation of the form $y^2$ + $a_{5}$ y = $x^{5}$ + $a_{5}$ x + $a_{10}$ ( $a_{5}$ $\neq$0).>0).

• 전자공학회논문지B
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• 제33B권1호
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• pp.25-37
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• 1996

실시간 컴퓨터 그래픽 처리를 위하여는 고속 연산(승산 및 가산)회로가 필요하다. 잉여수 체계(RNS:Residue Number System)는 병렬성과 고속성을 갖는 정수연산체계이고, 또한 순환군(cyclic group)은 가산과 승산이 동형인 잉여수 연산을 수행하므로 고속의 승산기와 가산기의 설계가 가능하다. 그러므로, 본 논문에서는 DRNS(Double Residue Number System)를 제안하고, 순환부호(circula- tive code)를 이용한 고속의 잉여수 승산기를 설계하여, 이를 그래픽 프로세서의 연산기로 사용하고자 한다. 설계된 승산기는 TTL소자 74s09, 74s32를 사용한 경우 87MHz속도의 연산이 가능하다.

• 한국경영과학회지
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• 제17권1호
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• pp.87-87
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• 1992

The Purpose of the current study is to understand population learning with coercive isomorphism in the Korean Business Groups. Can we observe isomorphic phenomena by coercive isomorphism? Why do these happen? What mechanisms are embedded in the coercive isomorphism. To answer these questions this study focused on the two Korea's largest Chaeblos the Samsung and Hyundai. An empirical study to compared daily routines used in these two Chaeboles and contents analysis on the founders' characteristics were performed. Three major mechanisms were suggested as main processes to impact the formation of the coercive isomorpism in the two Korean Chaebols. Research implications were discussed at the end of study.

• 대한수학회지
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• 제48권3호
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• pp.599-626
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• 2011

Let T = (V,A) be a tournament. With every subset X of V is associated the subtournament T[X] = (X, A ${\cap}$ (X${\times}$X)) of T, induced by X. The dual of T, denoted by $T^*$, is the tournament obtained from T by reversing all its arcs. Given a tournament T' = (V,A') and a non-negative integer ${\kappa}$, T and T' are {$-{\kappa}$}-hemimorphic provided that for all X ${\subset}$ V, with ${\mid}X{\mid}$ = ${\kappa}$, T[V-X] and T'[V-X] or $T^*$[V-X] and T'[V-X] are isomorphic. The tournaments T and T' are said to be hereditarily hemimorphic if for all subset X of V, the subtournaments T[X] and T'[X] are hemimorphic. The purpose of this paper is to establish the hereditary hemimorphy of the {$-{\kappa}$}-hemimorphic tournaments on at least k + 7 vertices, for every ${\kappa}{\geq}5$.

• 대한수학회보
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• 제57권1호
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• pp.207-218
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• 2020

Some modular representations of reflection groups related to Weyl groups are considered. The rational cohomology of the classifying space of a compact connected Lie group G with a maximal torus T is expressed as the ring of invariants, H*(BG; ℚ) ≅ H*(BT; ℚ)^W(G), which is a polynomial ring. If such Lie groups are locally isomorphic, the rational representations of their Weyl groups are equivalent. However, the integral representations need not be equivalent. Under the mod p reductions, we consider the structure of the rings, particularly for the Weyl group of symplectic groups Sp(n) and for the alternating groups A_n as the subgroup of W(SU(n)). We will ask if such rings of invariants are polynomial rings, and if each of them can be realized as the mod p cohomology of a space. For n = 3, 4, the rings under a conjugate of W(Sp(n)) are shown to be polynomial, and for n = 6, 8, they are non-polynomial. The structures of H*(BT^n-1; 𝔽_p)^A_n will be also discussed for n = 3, 4.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제9권1호
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• pp.69-96
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• 2005

Motivation for learning is important for positive learning outcomes as well as for measured achievement levels. When students come to our classes, they bring with them learning histories in which we as individual teachers, most likely, did not have an input. Our students do not only bring with them different levels of prerequisite leanings but also different levels of affect for what they will be learning. If we leave their final learning at the mercy of these entry characteristics, a test given the first day before the course will have almost isomorphic results with their achievement levels on the last day. The ones who had 'it' on the first day will be the ones who in the future will also have 'it', not too different from what the present situation is all over the world. These circumstances will tend to be the case ad infinitum, unless of course, we want to change the situation. This research clearly shows that effective instructional methodologies coupled with cooperative peer interactions not only have an impact on achievement but also on positive attitudes toward one's learning.

• 호남수학학술지
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• 제1권1호
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• pp.61-75
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• 1979

n-차원(次元) $C^{**}$ 다양체(多樣體)에서 얻어진 미분형식(微分形式)과 외미분(外微分)에 의하여 Rhan complex가 얻어지고 이것으로부터 얻어진 Cohomology를 Rham cohomology라 한다. n차원(次元) $C^{**}$ 다양체(多樣體)의 위상적(位相的) 구조(構造)만으로 정의(定義)되여진 Čech cohomology가 있는바 이것은 다양체(多樣體)의 피복(被覆)에 따라 그 cohomology 군(群)이 달라지는 것이 흠이다. 여기서는 Rham cohomology와 단순피복(單純被覆)을 취(取)하였을때의 Čech cohomology가 동형(同型)이 된다는 것의 증명(證明)의 개요(槪要)를 소개(紹介)하고 이것을 이용(利用) Rham cohomology ring과 Čech cohomology ring이 동형(同型)임을 증명(證明)한다. 그리고 이 de Rham 이론(理論)이 기하(幾何) 및 해석학(解析學)에 활용(活用)되는 일단(一端)을 기술(記述)하여 볼 예정(豫定)이다.

• Kyungpook Mathematical Journal
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• 제46권2호
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• pp.255-260
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• 2006

Let $m$ and $k$ be any positive integers, let $\mathbb{Z}_k$ the ring of integers of modulo $k$, let $G_m(\mathbb{Z}_k)$ the group of all $m$ by $m$ nonsingular matrices over $\mathbb{Z}_k$ and let ${\phi}_m(k)$ the order of $G_m(\mathbb{Z}_k)$. In this paper, ${\phi}_m(k)$ can be computed by the following investigation: First, for any relatively prime positive integers $s$ and $t$, $G_m(\mathbb{Z}_{st})$ is isomorphic to $G_m(\mathbb{Z}_s){\times}G_m(\mathbb{Z}_t)$. Secondly, for any positive integer $n$ and any prime $p$, ${\phi}_m(p^n)=p^{m^2}{\cdot}{\phi}_m(p^{n-1})=p{^{2m}}^2{\cdot}{\phi}_m(p^{n-2})={\cdots}=p^{{(n-1)m}^2}{\cdot}{\phi}_m(p)$, and so ${\phi}_m(k)={\phi}_m(p_1^n1){\cdot}{\phi}_m(p_2^{n2}){\cdots}{\phi}_m(p_s^{ns})$ for the prime factorization of $k$, $k=p_1^{n1}{\cdot}p_2^{n2}{\cdots}p_s^{ns}$.