• Safety and Health at Work
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• v.14 no.1
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• pp.100-106
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• 2023

Background: Our study aimed to investigate the mediating role of work-family conflict (WFC) on the relationship between long commutes and workers' anxiety and insomnia. Methods: Our study measured the two dimensions of WFC, time-related, and strain-related, which were considered multiple mediators. The mediating effect of WFC on anxiety and insomnia was investigated by decomposing the total effect into a direct effect (long commuting time → anxiety or insomnia) and an indirect effect (long commuting time → WFC → anxiety or insomnia). The combined indirect effect (joint indirect effect) of strain-related WFC and time-related WFC was estimated. The effects were presented as odds ratios and 95% confidence intervals (CIs). Results: The direct effect of 120 min or longer of commuting time was 1.39 (95% CI: 1.17-1.65) times increase in the odds of anxiety and 1.64 (95% CI: 1.41-1.90) times increase in the odds of insomnia than those whose commuting time was less than 60 min. In the case of indirect effects, those whose commuting time was 120 min or longer had 1.13 times higher odds of anxiety (95% CI: 1.07-1.18) and 1.12 times higher odds of insomnia (95% CI: 1.07-1.17) via WFC. The joint indirect effects accounted for 26.4% and 18.5% of the total effect on anxiety and insomnia, respectively. The longer the commuting time, the stronger both direct and indirect effects. Conclusions: Our findings highlight the mediating effect of WFC on the relationship between long commuting times and workers' anxiety and insomnia.

• Honam Mathematical Journal
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• v.36 no.1
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• pp.157-165
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• 2014

In this paper, we obtain some common fixed point theorems of single and multivalued maps under hybrid contractive conditions satisfying weakly commuting in IFMS. Our results extend previous ones in IFMS.

• Bulletin of the Korean Mathematical Society
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• v.54 no.5
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• pp.1669-1675
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• 2017

The group of automorphisms of the first Weyl algebra acts on commuting ordinary differential operators with polynomial coefficient. In this paper we prove that for fixed generic spectral curve of genus two the set of orbits is infinite.

• Communications of the Korean Mathematical Society
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• v.33 no.4
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• pp.1097-1102
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• 2018

Let A and B be matrices which are polynomials in r pairwise commuting nilpotent matrices over a field. We give a sufficient condition for the null space of $A^i$ to equal that of $B^i$ for all i, in particular, for A and B to be similar.

• Journal of the Chungcheong Mathematical Society
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• v.32 no.4
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• pp.475-490
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• 2019

Let C^(q) be the q-commuting arithmetic table of (x + y)ⁿ with noncommuting variables. We study sequential properties of diagonal sums of C^(q) with various q > 0. One of our results shows that each diagonal sum plays like Fibonacci number with some minor conditions.

• Journal of the Chungcheong Mathematical Society
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• v.33 no.4
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• pp.413-427
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• 2020

In this work we study 0-commuting matrix C(0) under relationships with the Pascal matrix C(1). Like kth power C(1)k is an arithmetic matrix of (kx+y)n with yx = xy (k ≥ 1), we express C(0)k as an arithmetic matrix of certain polynomial with yx = 0.

• East Asian mathematical journal
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• v.39 no.3
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• pp.279-290
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• 2023

We study divisibilities of elements in the q-commuting matrix C^(q). We first make a coefficient matrix Ĉ of C^(q) which is independent of q, study divisibilities over Ĉ and then retrieve our findings to C^(q). Finally we partition the C^(q) into 2 × 2 block matrices.

• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.102-115
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• 2004

As a household's residential location is closely related to its workplace and place of education, the urban exodus of city dwellers changes their ways of commuting to workplace and attending school. This paper examines the influence of urban exodus on the change of a way of life through relations between residential location and modes of commuting. Despite moving to the countryside, exurban migrants still want to experience rural health without abandoning the city lifestyle. However, they are faced with various difficulties in commuting to workplace and attending school, because suburban and exurban areas have poor accessibility to the central city. In order to overcome these problems, most of them choose "the residential segmentation of the family" through which the head of the family commutes to the city from his or her family home in exurban areas and children go to school from their second home in the central city, or try "to link commuting to workplace with attending school".

• Journal of Korean Society of Transportation
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• v.11 no.1
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• pp.5-22
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• 1993

This study examines the 1980 Census and the 1987 Travel Survey data sets, in order to identify commuting trends in the Seoul Metropolitan Area. The commuting field of Seoul includes the cities and counties contiguous to Seoul, as well as Inchon, Suwon and Ansan City and Paju County. The study finds little support for the expansion of the commuting field toward distant counties of Kyonggi Province; instead an intensification of commuting within the field is more salient. The most prominent trend, within the city limit of Seoul, is that journey-to-work toward the city center has decreased whereas peripheral journeys increased considerably. The work trips have increased most in the southwestern sector of the city; a moderate increase in the northeastern and southwestern sectors; and decreases in the center and the northwestern sector of the city. Factorial analyses of the work trip data also reveal the emergence of sub-regions of journey-to-work in the peripheries of the city. Such a spatial pattern of commuting changes resemble that of population changes, and correspond in part to the layout of the subway system.

• Bulletin of the Korean Mathematical Society
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• v.59 no.6
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• pp.1567-1594
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• 2022

In this article, we first introduce the notion of commuting Ricci tensor and pseudo-anti commuting Ricci tensor for Hopf hypersurfaces in the homogeneous nearly Kähler 𝕊³ × 𝕊³ and prove that the mean curvature of hypersurface is constant under certain assumptions. Next, we prove the nonexistence of Ricci soliton on Hopf hypersurface with potential Reeb vector field, which improves a result of Hu et al. on the nonexistence of Einstein Hopf hypersurfaces in the homogeneous nearly Kähler 𝕊³ × 𝕊³.