• 대한수학회지
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• 제48권1호
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• pp.83-104
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• 2011

In this note, compound-commuting additive maps on matrix spaces are studied. We show that compound-commuting additive maps send rank one matrices to matrices of rank less than or equal to one. By using the structural results of rank-one nonincreasing additive maps, we characterize compound-commuting additive maps on four types of matrices: triangular matrices, square matrices, symmetric matrices and Hermitian matrices.

• Kyungpook Mathematical Journal
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• 제47권2호
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• pp.277-281
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• 2007

There are many papers on linear operators that preserve commuting pairs of matrices over fields or semirings. From these research works, we have a motivation to the research on the linear operators that preserve commuting pairs of matrices over nonnegative integers. We characterize the surjective linear operators that preserve commuting pairs of matrices over nonnegative integers.

• 호남수학학술지
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• 제34권1호
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• pp.77-84
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• 2012

In this paper, we define the weakly commuting mapping and prove the fixed point theorem for weakly commuting mappings under some conditions on intuitionistic fuzzy metric spaces.

• 대한수학회보
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• 제36권2호
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• pp.351-355
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• 1999

If ($H_1$, $H_2$) is a doubly commuting pair of hyponormal operators on a Hilbert spaces H, then there exists a commuting pair ($T_1$,$T_1$) of contractions on H such that $H_i$=$H_i^*$$T_i$ for each i=1,2.

• 한국ITS학회 논문지
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• 제20권5호
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• pp.172-185
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• 2021

자율주행시대가 우리 삶에 다가오면서 삶의 변화에 많은 영향을 미칠 것으로 예상된다. 자율주행자동차가 등장하면 운전자의 부담을 줄임으로 차내에서 생산적 가치가 확장되는 만큼 이를 평가할 수 있는 지표개발이 필요하다. 이번 연구는 경기도 직장인 중 승용차를 이용하는 통근자를 대상으로 자율주행 자동차가 통근시간 및 통근시간 만족도에 어떠한 영향을 미치는지 분석하였다. 통근시간 및 통근시간 만족도는 비선형 관계(V)가 도출되었다. 여기서, 자율주행시대에 영향받을 가능성이 높은 비선형 구간인 통근시간 70분 이상영역을 중심으로 이항로지스틱 모형을 통해 분석하였다. 분석결과 자율주행시대의 영향변수로는 건강도, 수면시간, 근무시간, 여가시간 등이 도출되었다. 자율주행자동차의 등장은 이러한 변수를 개선시킬 가능성이 높으므로 장거리 통근자의 통근시간 만족도는 개선될 가능성이 높다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제22권2호
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• pp.127-138
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• 2015

The object of this paper is to emphasize the role of 'common limit range property' and utilize the same with variants of R-weakly commuting mappings for the existence of common fixed point under strict contractive conditions in metric spaces. We also furnish some interesting examples to validate our main result. Our results improve a host of previously known results including the ones contained in Pant [Contractive conditions and common fixed points, Acta Math. Acad. Paedagog. Nyhàzi. (N.S.) 24(2) (2008), 257-266 MR2461637 (2009h:54061)]. In the process, we also derive a fixed point result satisfying $\phi$-contractive condition.

• 대한수학회논문집
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• 제20권1호
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• pp.23-34
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• 2005

Let R be a ring with left identity. Let G : $R{\times}R{\to}R$ be a symmetric biadditive mapping and g the trace of G. Let ${\alpha}\;:\;R{\to}R$ be an endomorphism and ${\beta}\;:\;R{\to}R$ an epimorphism. In this paper we show the following: (i) Let R be 2-torsion-free. If g is (${\alpha},{\beta}$)-skew-commuting on R, then we have G = 0. (ii) If g is (${\beta},{\beta}$)-skew-centralizing on R, then g is (${\beta},{\beta}$)-commuting on R. (iii) Let $n{\ge}2$. Let R be (n+1)!-torsion-free. If g is n-(${\alpha},{\beta}$)-skew-commuting on R, then we have G = 0. (iv) Let R be 6-torsion-free. If g is 2-(${\alpha},{\beta}$)-commuting on R, then g is (${\alpha},{\beta}$)-commuting on R.

• 가정과삶의질연구
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• 제21권2호
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• pp.213-220
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• 2003

In this study, I analyzed dual-career commuting couples time use. Concretely, this study compared the husband with the wife on the becoming a commuter family, the living apart on weekdays. And it examined time use on weekdays and weekends by the time amount of each activities and the ratio of actor on each hour. The survey participants included 131 married people who were dual-career commuting couple and who were maintained separate residence and work place. The major findings are as follows: First, weekday separation of the dual-career commuting couples is largely due to career. This kind separation is mostly due to sociostructural labor market factor and individual factor to increasing working women. Second, 94.6%(53) of male participants were resident living apart from their family on weekdays. Third, the most wives mentioned some kind of emotional liberation such as freedom on weekdays. Finally, there was gender difference in the time spent on each activities when dual-career commuting couples are living together and they are apart. Especially the most gender difference on weekdays is household work time and leisure time.

• 한국경제지리학회지
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• 제14권3호
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• pp.437-451
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• 2011

본 연구에서는 서울의 인구집중 해소와 함께 자족기능을 갖춘 도시의 개발을 목적으로 수도권 1기 신도시 건설계획이 수립된 이후 20여년이 경과한 시점에서 그간 서울시 거주자의 통근통행패턴에 어떤 변화가 있었는지 살펴보았다. 우선 통근시간에 영향을 주는 요인을 판별하기 위해 가구통행실태조사 자료를 이용하여 다중회귀분석을 실시한 후, 초과통근 실태를 분석하여 서울시의 직주 불일치 정도를 알아보았다. 분석결과에 따르면, 통근자들은 소득이 높아질수록 통근시간이 늘어나다가 일정 수준에 다다르면 통근시간이 줄어드는 양상을 보였다. 또한 서울시의 통근비용이 최소화되는 경우에 비해 상당한 수준의 초과통근이 이루어지고 있는 것으로 나타났다. 전체적으로 서울의 직주 불일치가 과거에 비해 완화된 것으로 나타나나, 행정구별로는 여전히 직주 불일치도의 격차가 심하였다. 수도권 신도시 건설 이후 서울 거주자들의 통근패턴 변화와 현재의 직주불일치 정도를 파악한 본 연구 결과를 통해 비효율적 통근 문제의 해결책을 모색하고, 지속가능한 도시개발을 가능케 하는 정책이 수립될 수 있을 것이다.

• 한국농공학회논문집
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• 제62권1호
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• pp.29-38
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• 2020

Although educational facilities are important considerations from a social equity standpoint, the educational environment generally found in rural areas has been continuously deteriorated due to numerous social problems following birth rate declines and school abolition numbers. The purpose of this study is to evaluate the commuting accessibility changed by the abolition of elementary schools. The village-level accessibility is assessed following physical accessibility criteria based on legally defined commuting distances. Moreover, this study shows the implications of commuting accessibility by school district zones through comparing the minimum commuting distances with real commuting distance. The target area is the Gangwon state, the coverage area in which for schools is the widest in South Korea (44.1 ㎢/school). We evaluated the commuting distances to the nearest elementary school for 992 rural villages and 74 urban villages. Of the 1,066 villages in urban and rural areas evaluated, most of the villages (about 77%) are exposed to commutes to elementary schools were the marginal distance is over 1,000 meters. The annual rate of increase of commuting distance for 1,066 villages in Gangwon state has steadily increased by 2.8%p since 2000, average commuting distance from 2.8 km to 3.6 km. By the designation of the school districts, elementary school students have to go to a faraway school located within administrative district, even though there is a school nearby. It is expected that the results of this study will be made use of as basic data for the establishment of policies such as a reasonable basis for closing schools measurements considering the locally unique environment.