• Journal of applied mathematics & informatics
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• 제25권1_2호
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• pp.155-167
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• 2007

A graph G is called to be a 2-degree integral subgraph of a q-tree if it is obtained by deleting an edge e from an integral subgraph that is contained in exactly q - 1 triangles. An added-vertex q-tree G with n vertices is obtained by taking two vertices u, v (u, v are not adjacent) in a q-trees T with n - 1 vertices such that their intersection of neighborhoods of u, v forms a complete graph $K_{q}$, and adding a new vertex x, new edges xu, xv, $xv_{1},\;xv_{2},\;{\cdots},\;xv_{q-4}$, where $\{v_{1},\;v_{2},\;{\cdots},\;v_{q-4}\}\;{\subseteq}\;K_{q}$. In this paper we prove that a graph G with minimum degree not equal to q - 3 and chromatic polynomial $$P(G;{\lambda})\;=\;{\lambda}({\lambda}-1)\;{\cdots}\;({\lambda}-q+2)({\lambda}-q+1)^{3}({\lambda}-q)^{n-q-2}$$ with $n\;{\geq}\;q+2$ has and only has 2-degree integral subgraph of q-tree with n vertices and added-vertex q-tree with n vertices.

• Steel and Composite Structures
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• 제48권6호
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• pp.611-623
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• 2023

This work considered an optimal control formulation in the sense of Caputo derivatives. The optimality of the fractional optimal control problem. The tumor immune interaction in fractional form provides an excellent tool for the description of memory and hereditary properties of inter and intra cells. So the interaction between effector-cells, tumor cells and are modeled by using the definition of Caputo fractional order derivative that provides the system with long-time memory and gives extra degree of freedom. In addiltion, existence and local stability of fixed points are investigated for discrete model. Moreover, in order to achieve more efficient computational results of fractional-order system, a discretization process is performed to obtain its discrete counterpart. Our technique likewise allows the advancement of results, such as return time to baseline that are unrealistic with current model solvers.

• 대한수학교육학회지:수학교육학연구
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• 제12권1호
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• pp.49-70
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• 2002

There have recently been increasing exchanges between South and North Korea in many areas of society, involving politics, economics, culture, education. In response to these developments, research activities are more strongly demanded in each of these areas to help prepare for the final unification of the two parts of the nation. In the area of mathematics education, scholars have started to conduct comparative studies of mathematics education in South and North Korea. As a response to the growing demand of the time, in this thesis we compared the secondary mathematics education in South Korea with that in North Korea. To begin with, we examined the background of education, in North Korea, particularly predominant ideological, epistemological and teaching theoretical aspects of education in North Korea. Thereafter, we compared the mathematics curriculum of South Korea with that of North Korea. On the basis of these examinations, we compared the secondary school mathematics textbooks of South and North Korea, and we attempted to suggest a guideline for researches preparing for the unification of the mathematics curriculum of South and North Korea. As a communist society, North Korea awards the socialist ideology the supreme rank and treats all school subjects as instrumental tools that are subordinated to the dominant communist ideology. On the other hand, under the socialist ideology North Korea also emphasizes the achievement of the objective of socialist economic development by expanding the production of material wealth. As such, mathematics in North Korea is seen as a tool subject for training skilled technical hands and fostering science and technology, hence promoting the socialist material production and economic development. Hence, the mathematics education of North Korea adopts a so-called "awakening teaching method," and emphasizes the approaches that combine intuition with logical explanation using materials related with the ideology or actual life. These basic viewpoints of North Korea on mathematics education are different from those of South Korea, which emphasize the problem-solving ability and acquisition of academic mathematical knowledge, and which focus on organizing as well as discovering knowledge of learners' own accord. In comparison of the secondary school mathematics textbooks used in South and North Korea, we looked through external forms, contents, quantity of each area of school mathematics, viewpoints of teaching, and term. We have identified similarities in algebra area and differences in geometry area especially in teaching sequence and approaching method. Many differences are also found in mathematical terms. Especially, it is found that North Korea uses mathematical terms in Hangul more actively than South Korea. We examined the specific topics that are treated in both South and North Korea, "outer-center & inner-center of triangle" and "mathematical induction", and identified such differences more concretely. Through this comparison, it was found that the concrete heterogeneity in the textbooks largely derive from the differences in the basic ideological viewpoints between South and North Korea. On the basis of the above findings, we attempted to make some suggestions for the researches preparing for the unification in the area of secondary mathematics education.

• 대한수학회보
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• 제53권1호
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• pp.139-151
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• 2016

A k-total-coloring of a graph G is a coloring of $V{\cup}E$ using k colors such that no two adjacent or incident elements receive the same color. The total chromatic number ${\chi}^{{\prime}{\prime}}(G)$ of G is the smallest integer k such that G has a k-total-coloring. Let G be a planar graph with maximum degree ${\Delta}$. In this paper, it's proved that if ${\Delta}{\geq}7$ and G does not contain adjacent 5-cycles, then the total chromatic number ${\chi}^{{\prime}{\prime}}(G)$ is ${\Delta}+1$.

• 대한수학회보
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• 제50권2호
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• pp.353-373
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• 2013

In this paper, a class of delayed predator-prey models of prey migration and predator switching is considered. By analyzing the associated characteristic transcendental equation, its linear stability is investigated and Hopf bifurcation is demonstrated. Some explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using the normal form theory and center manifold theory. Some numerical simulations for justifying the theoretical analysis are also provided. Finally, biological explanations and main conclusions are given.

• 동아시아경상학회지
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• 제5권1호
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• pp.33-49
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• 2017

This article can see the analysis of the monetary market of Russia at the present stage, its main segments. An assessment is given to the regulation of mechanism by liquidity, the transactions of the Bank of Russia on the provision of liquidity and on absorption of liquidity, the transaction of fixed action and the transaction in the public market are analyzed. To determine the tendency of development of the monetary market and its segments. In the work using the methods of multivariate statistics, the tools of financial mathematics. To be analyzed the amount of data from the 2015 -2016 year, the 2013 year. (daily data). Hypothesis 1. The dynamics of the money market of Russia at the present stage of development of domestic economy is rather stable. Hypothesis 2.The many transactions of regulation to decrease the liquidity of by monetary movement, the control function. Also in the article consider the contour of the financial transaction. This article reveals the theoretical bases of analysis of profitability of credit operations.

• 호남수학학술지
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• 제35권2호
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• pp.225-234
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• 2013

Many studies of experimental economics have produced outcomes which contradict the predictions of Nash equilibrium, which relies heavily upon the premise of selfishness of an individual. In the games involving contexts of social conflicts represented by the prisoners' dilemma game, the experiments yields outcomes quite different from what are predicted by the conventional wisdom. In order to fill this gap between the conventional Nash Equilibrium and experimental outcomes, non-selfish (or other-regarding) motives of human behavior are introduced and then a new equilibrium concept, RAE-equilibrium is developed. It is also proved that an RAE-equilibrium exists under quite general conditions. Then it is applied to the prisoners' dilemma game that some of the experimental outcomes can be explained.

• 한국의상디자인학회지
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• 제18권2호
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• pp.145-159
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• 2016

This study developed the learning criteria for Science, Technology, Engineering, Arts & Mathematics to establish the theoretical background of the education pursued by STEAM. The learning criteria was developed on a basis of 6 kinds of Technology Home Economics textbooks by 2009 Amended Curriculum, and the factors of STEAM were extracted according to related contents. From the results of this study, the unit 'Dress and Self-expression' assimilated T.E.A.M with learning related to clothing psychology, consumer behavior, fashion design, and Korean fashion. The unit 'eco-friendly clothing and fixing clothes' was found to assimilate S.T.E.A.M. with learning related to clothes science and dress structure. Accordingly we can understand this unit also consists of the S. T. E. A. M assimilation such as clothes science, fashion marketing, dress structure, dress aesthetics, design and so on. Both units 'dress and self-expression' and 'eco-friendly clothing and fixing clothes' were found to consist of suggesting situations, creative planning and emotional experience following the learning criteria of STEAM. Therefore, these units will be the basic material for developing STEAM programs centering upon 'Home Economics' among the curriculum.

• The Journal of Asian Finance, Economics and Business
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• 제7권8호
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• pp.519-531
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• 2020

This research aims to identify the determinants of e-government satisfaction in Hanoi, Vietnam, and assess their impact. To collect data, we conducted an online questionnaire with citizens living in Hanoi in a time span of five weeks. We received 1,107 responses, divided into three groups: unaware, known, but not used, and used e-government. After leveraging past studies on satisfaction in different contexts, we arrived at six external variables that are of particular relevance to e-government satisfaction (i.e., efficiency, trust, reliability, convenience, citizen support, and transparency) as well as four control variables (i.e., age, gender, education level, and Internet frequency). We then applied both SPSS 22 and STATA 2016 to process and analyze the collected data and found that, while almost all external variables are statistically significant, all four control variables are not. Apart from convenience and trust, four factors - efficiency, reliability, citizens support, transparency - are important measures of system quality, information quality, service quality and relative benefits of e-government, which in turn positively and significantly impact citizens' satisfaction with the online public services. Furthermore, the efficiency variable has the most influence on customer satisfaction, and the level of impact on the dependent variable decreases in the following order: citizen support, reliability and transparency.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.927-938
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• 2021

Small and Medium Enterprises (SMEs) is one of several activators that drives the economy of Indonesia because SMEs provide jobs, increase Gross Domestic Product (GDP), and assure the delivery of products and services. However, Indonesian SMEs are not very competitive in the industrial world, and one of the causes is the low quality of products that undermine customer satisfaction. There are several factors presumed as influencing customer satisfaction, which among others include product knowledge, service quality, and competitive advantage. The objective of this research is to reveal the contribution of product knowledge and service quality to customer satisfaction with competitive advantage as the mediation variable. This research used a quantitative approach. The causal relationship across variables was examined with Structural Equation Modeling-Partial Least Squares (SEM-PLS). The sample of this research involved 140 respondents. Data was collected through a questionnaire and the items in the questionnaire were processed with a software called SmartPLS version 3.3.2. Results of this research indicate (1) product knowledge and service quality can increase competitive advantage and customer satisfaction in East Java SMEs; (2) competitive advantage can act as a mediator in the effect of service quality on customer satisfaction (3) product knowledge can increase customer satisfaction but the increase is not significant statistically.