• Bulletin of the Korean Mathematical Society
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• v.47 no.1
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• pp.17-27
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• 2010

A Cayley map is a 2-cell embedding of a Cayley graph into an orientable surface with the same local orientation induced by a cyclic permutation of generators at each vertex. In this paper, we provide classifications of prime-valent regular Cayley maps on abelian groups, dihedral groups and dicyclic groups. Consequently, we show that all prime-valent regular Cayley maps on dihedral groups are balanced and all prime-valent regular Cayley maps on abelian groups are either balanced or anti-balanced. Furthermore, we prove that there is no prime-valent regular Cayley map on any dicyclic group.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.145-158
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• 2005

We formulate a stochastic control problem on proportional reinsurance that includes impulse and regular control strategies. For the first time we combine impulse control with regular control, and derive the expected total discount pay-out (return function) from present to bankruptcy. By relying on both stochastic calculus and the classical theory of impulse and regular controls, we state a set of sufficient conditions for its solution in terms of optimal return function. Moreover, we also derive its explicit form and corresponding impulse and regular control strategies.

• The Journal of Korean Society for School & Community Health Education
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• v.23 no.2
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• pp.65-76
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• 2022

Objectives: The purpose of this study is to investigate the factors that affect the smoking type among those who have used regular cigarettes, liquid or cigarette-type e-cigarettes. Methods: The subjects of analysis were 6,081 people who had smoked regular cigarettes or e-cigarettes. For data analysis, SPSS ver.25.0 statistical package program was used. Multinomial logistic regression analysis was performed to find out the factors affecting smoking type. Results: Factors affecting the experience of using e-cigarettes compared to regular cigarette smoking are gender and class. Academic performance, living with family members, drinking experience, and secondhand smoke in school. The factors influencing dual use compared to regular cigarette smoking were gender, class, academic performance, economic status, living with family, drinking experience, and experience of secondhand smoke in school. Smoking cessation attempts had an effect on dual use compared to regular cigarette smoking. Conclusion: Smoking cessation experience had a greater effect on e-cigarette use than regular cigarette smoking.

• Communications of the Korean Mathematical Society
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• v.39 no.2
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• pp.363-372
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• 2024

In this paper, we introduce a weak version of coherent that we call regular coherent property. A ring is called regular coherent, if every finitely generated regular ideal is finitely presented. We investigate the stability of this property under localization and homomorphic image, and its transfer to various contexts of constructions such as trivial ring extensions, pullbacks and amalgamated. Our results generate examples which enrich the current literature with new and original families of rings that satisfy this property.

• Journal of Korean Public Health Nursing
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• v.33 no.2
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• pp.270-283
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• 2019

Purpose: The aim of this study was to identify the job insecurity, job satisfaction, and organizational commitment of non-regular visiting nurses working at public health centers, and evaluate the effects of job insecurity on the job satisfaction and organizational commitment. Methods: This study was a descriptive survey study. One hundred forty-three visiting nurses, who were non-regular hired by 16 public health centers in B city, were selected using a convenient sampling method. Results: The results were analyzed using SPSS/Win 21.0. A feeling of helplessness (among job insecurity factors) and retention intention significantly affected the job satisfaction of non-regular visiting nurses, and their explanation power was 20%. Retention intention, a feeling of helplessness, and age significantly influenced the organizational commitment, and their explanation power was 26%. Conclusion: Therefore, it would be necessary to stabilize the employment type, provide appropriate promotion and compensation for nurses according to their work performance, and reduce the number of non-regular employees to increase the job satisfaction and organizational commitment of non-regular visiting nurses.

• Bulletin of the Korean Mathematical Society
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• v.59 no.3
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• pp.617-642
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• 2022

For positive integers n and d with d < n, an n × n array A based on 𝒳 = {0, 1, …, nd} is called a sparse anti-magic square of order n with density d, denoted by SAMS(n, d), if each non-zero element of X occurs exactly once in A, and its row-sums, column-sums and two main diagonal-sums constitute a set of 2n + 2 consecutive integers. An SAMS(n, d) is called regular if there are exactly d non-zero elements in each row, each column and each main diagonal. In this paper, we investigate the existence of regular sparse anti-magic squares of order n ≡ 1, 5 (mod 6), and prove that there exists a regular SAMS(n, d) for any n ≥ 5, n ≡ 1, 5 (mod 6) and d with 2 ≤ d ≤ n - 1.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.333-339
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• 2003

In this paper, we develop the probability matching priors for the parameters of non-regular Pareto distribution. We prove the propriety of joint posterior distribution induced by probability matching priors. Through the simulation study, we show that the proposed probability matching Prior matches the coverage probabilities in a frequentist sense. A real data example is given.

• Korean Journal of Mathematics
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• v.20 no.2
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• pp.177-184
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• 2012

In this paper, we study the four different types of relations, $\mathcal{P}(X,T)$, $\mathcal{R}(X,T)$, $\mathcal{L}(X,T)$, and $\mathcal{S}(X,T)$ in a transformation (X,T), and obtain some of their properties. In particular, we give a relationship between $\mathcal{R}(X,T)$ and $\mathcal{S}(X,T)$.

• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.119-133
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• 2011

This paper proposes an infeasible interior-point algorithm with full-Newton step for linear programming. We introduce a special self-regular proximity to induce the feasibility step and also to measure proximity to the central path. The result of polynomial complexity coincides with the best-known iteration bound for infeasible interior-point methods, namely, O(n log n/${\varepsilon}$).

• Journal of the Korean Mathematical Society
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• v.56 no.2
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• pp.475-484
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• 2019

We study the set of critical exponents of discrete groups acting on regular trees. We prove that for every real number ${\delta}$ between 0 and ${\frac{1}{2}}\;{\log}\;q$, there is a discrete subgroup ${\Gamma}$ acting without inversion on a (q+1)-regular tree whose critical exponent is equal to ${\delta}$. Explicit construction of edge-indexed graphs corresponding to a quotient graph of groups are given.