• Korean Journal of Mathematics
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• 제11권2호
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• pp.147-153
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• 2003

We investigate some properties on right(resp. left) duo $po$-semigroups.

• 대한수학회보
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• 제36권1호
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• pp.139-146
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• 1999

It is known that a right nilpotent congruence $\beta$ on a finite algebra A is also left nilpotent [3]. The question on whether the left nilpotency class of $\beta$ in less than or equal to the right nilpotency class of $\beta$is still open. In this paper we find an upper limit for the left nilpotency class of $\beta$. In addition, under the assumption that 1 $\in$ typ{A}, we show that $(\beta]^k=[\beta)^k$ for all k$\geq$1. Thus the left and right nilpotency classes of $\beta$ are the same in this case.

• Korean Journal of Mathematics
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• 제14권2호
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• pp.241-248
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• 2006

We define a G-fuzzy congruence, which is a generalized fuzzy congruence, and characterize the G-fuzzy congruence generated by a left and right compatible fuzzy relation on a semigroup.

• 충청수학회지
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• 제24권3호
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• pp.449-456
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• 2011

In this paper, we considered the congruence relation, isomorphism and obtained some properties of HS-algebras.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제4권2호
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• pp.131-135
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• 1997

We give the relation between the semilattice congruence N and the set of prime ideals of the ordered $\Gamma$-semigroup M.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제12권4호
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• pp.253-274
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• 2005

An additive regular Semiring S is left inversive if the Set E+ (S) of all additive idempotents is left regular. The set LC(S) of all left inversive semiring congruences on an additive regular semiring S is a lattice. The relations $\theta$ and k (resp.), induced by tr. and ker (resp.), are congruences on LC(S) and each $\theta$-class p$\theta$ (resp. each k-class pk) is a complete modular sublattice with $p_{min}$ and $p_{max}$ (resp. With $p^{min}$ and $p^{max}$), as the least and greatest elements. $p_{min},\;p_{max},\;p^{min}$ and $p^{max}$, in particular ${\epsilon}_{max}$, the maximum additive idempotent separating congruence has been characterized explicitly. A semiring is quasi-inversive if and only if it is a subdirect product of a left inversive and a right inversive semiring.

• 대한수학회논문집
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• 제13권1호
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• pp.1-6
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• 1998

The paper refers to ordered semigroups in which $x^2 (x \in S)$ are left ideal elements. We mainly show that this $po$-semigroup is left regular if and only if S is a union of left simple subsemigroups of S.

• 한국지능시스템학회논문지
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• 제17권1호
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• pp.100-111
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• 2007

We introduce the concept of intuitionistic fuzzy G-equivalence relations (congruence), and we obtain some results. Furthermore, we prove that $IFC_G(K)$ is isomorphic to $IFN^*(K)$ for any group K. Also, we prove that($IFC_{G,({\lambda},{\mu})}/{\sim},\;*$) and ($IFNG_{({\lambda},{\mu})}(K),\;{\circ}$) are isomorphic.

• 의정연구
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• 제23권2호
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• pp.67-108
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• 2017

대의 민주주의에 있어 대표자가 얼마나 시민의 이념적 선호를 대변하는지는 매우 중요한 문제이다. 의회 혹은 정부와 시민 간의 이념적 일치는 주로 정당정치가 오래된 서구 민주주의 국가를 중심으로 연구되어 왔으나, 민주주의의 역사가 비교적 짧은 우리나라에서는 아직 많은 연구가 이루어지지 못했다. 본 논문은 2002년부터 2016년까지의 설문자료를 바탕으로 한국 정치공간의 시민과 대표 간 이념적 일치를 다양한 방식으로 개념화하고 측정하였다. 먼저 좌-우의 단차원적 공간으로 분석한 결과, 시민과 국회 간의 이념적 거리와 달리 시민과 정부 간의 거리는 2000년대 이후 꾸준히 증가하고 있는 것으로 나타났다. 이러한 여야 간 양극화와 정부의 대표성 악화는 민주주의의 규범적 측면에서 부정적이라 할 수 있다. 하지만 다차원적 공간에서 정부와 시민 간의 이념적 거리는 쟁점에 따라 다르게 나타났는데, 대북지원에서는 2008년 보수정권이 들어선 이후 점차 증가한 반면, 복지정책의 경우는 이전의 진보 정권에 비해 악화된 것으로 조사되었다. 이렇게 쟁점별로 이념적 일치가 다르게 나타난다는 점은 시민과 정당 모두에게 많은 점을 시사한다. 시민들에게는 단차원적 이념을 넘어 자신에게 가장 중요한 쟁점을 대변하는 대표자를 구별하는 능력이, 정당에게는 기존의 지지층과 함께 늘어나는 무당층을 대변하기 위해 효과적인 당 조직의 정비와 프로그램 마련이 요구되고 있는 것이다.

• 한국수학교육학회지시리즈A:수학교육
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• 제46권3호
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• pp.273-292
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• 2007

The purpose of this study was to find out how second, fourth and sixth graders understood the main contents related to spatial sense in the Seventh National Mathematics Curriculum. For this purpose, this study examined students' understanding of the main contents of congruence transformation (slide, flip, turn), mirror symmetry, cubes, congruence and symmetry. An investigation was conducted and the subjects included 483 students. The main results are as follows. First, with regards to congruence transformation, whereas students had high percentages of correct answers on questions concerning slide, they had lower percentages on questions concerning turn. Percentages of correct answers on flip questions had significant differences among the three grades. In addition, most students experienced difficulties in describing the changes of shapes. Second, students understood the fact that the right and the left of an image in a mirror are exchanged, but they had poor overall understanding of mirror symmetry. The more complicated the cubes, the lower percentages of correct answers. Third, students had a good understanding of congruences, but they had difficulties in finding out congruent figures. Lastly, they had a poor understanding of symmetry and, in particular, didn't distinguish a symmetric figure of a line from a symmetric figure of a point.