• Journal of the Korean Mathematical Society
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• v.48 no.1
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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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• v.47 no.2
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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.

• Honam Mathematical Journal
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• v.34 no.1
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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.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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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.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.172-185
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• 2021

As the era of autonomous driving approaches, it is expected to have a significant impact on our lives. When autonomous driving cars emerge, it is necessary to develop an index that can evaluate autonomous driving cars as it enhance the productive value of the car by reducing the burden on the driver. This study analyzed how the autonomous driving era affects commuting time and commuting time satisfaction among office goers using a car in Gyeonggi-do. First, a nonlinear relationship (V) was derived for the commuting time and commuting time satisfaction. Here, the factors affecting commuting time satisfaction were analyzed through a binomial logistic model, centered on the sample belonging to the nonlinear section (70 minutes or more for commuting time), which is likely to be affected by the autonomous driving era. The analysis results show that the variables affected by the autonomous driving era were health, sleeping hours, working hours, and leisure time. Since the emergence of autonomous driving cars is highly likely to improve the influencing variables, long-distance commuters are likely to feel higher commuting time satisfaction.

• The Pure and Applied Mathematics
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• v.22 no.2
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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.

• Communications of the Korean Mathematical Society
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• v.20 no.1
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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.

• Journal of Families and Better Life
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• v.21 no.2
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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.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.3
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• pp.437-451
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• 2011

The purpose of this study is to identify the factors that influence commuting patterns of Seoul residents after the construction of new towns. To find the determinants of commuting time for residents with jobs in Seoul, a multiple regression analysis is performed using household survey data. Overall, the findings present a plausible picture of the spatial configuration in Seoul, where younger residents with growing families move out to the suburbs to become owners of apartment homes, and drive or use mass transportation to get to work. As they get older and wealthier, other things being equal, they gravitate towards the city centre in order to reduce the time wasted on commuting. While their occupations appear to play little role, it seems that the entrapment hypothesis on female workers is supported as well. In addition, excess commuting is still prevalent due to jobs-housing mismatch in Seoul, although it is less severe than in the past. Based on these results, planners should devise better strategies to solve the inefficient commuting problem.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.1
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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.