• Kyungpook Mathematical Journal
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• 제28권1호
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• pp.97-106
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• 1988

In the first section of this paper two common fixed point results for four nonlinear mappings which are pairwise commuting and only two of them being continuous have been given on a complete metric space and on a compact metric space respectively which generalize the results of Mukherjee [2] and Yeh [4]. Further two common fixed point theorems have been established for two finite families of non linear mappings, with only one family being continuous. In another section we extend Theorem 3 and Theorem 4 of Mukherjee [2] for common fixed point of four continuous mappings on a Hausdorff space and on a compact metric space respectively. In the same spaces, these two results have been further generalized for two finite families of continuous mappings.

• 교육시설
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• 제11권5호
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• pp.5-13
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• 2004

To develop a master plan of a university campus, we need to know how students view and use their campus. For this purpose, the well-known Linch's(1960) cognitive mapping methods are used to figure out the image of Yonsei University and its surrounding area which is perceived by the students of Yonsei University. Major findings are that the cognition levels for the edge which divides Yonsei University from the surroundings and the paths which the students commute along are relatively high. The students mainly use campus space near the main gate rather than the space deep inside of the university, which shows they use the campus space unevenly. Therefore, when considering a new master plan of Yonsei University, it is needed to develop methods which increase the even use of the campus space such as developing new commuting paths.

• 산업공학
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• 제16권1호
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• pp.44-53
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• 2003

Ready-Mixed Concrete transportation business has been managed by the manual operation and intuitive decision making. This study is on the process improvement on ordering process, and allocation/transportation of trucks commuting between the batching plant and construction sites. Processes of order collection, job dispatch and allocation, and on-time-delivery are analysed and improved. The logistics control system, with GPS system, was developed and implemented based on the reconstructed processes. Performances are evaluated after improved business process and logistics system was applied, and it is shown that waiting time loss is decreased by 55%, and that efficiency is increased by 15%.

• 한국재난정보학회:학술대회논문집
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• 한국재난정보학회 2015년 정기학술대회
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• pp.175-185
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• 2015

본 연구에서는 TOD는 대중교통수단의 분담율 제고가 목적인데 이를 위한 정책대안의 모색에 필요한 새로운 분석기법을 제시하였다. 교통수단의 결정요인은 개인 특성과 라이프스타일 그리고 도시공간특성인데 이 요인들은 상호의존적으로 복합적 결합작용은 한다. 또한 개인과 그룹 및 지역 특성은 서로 다른 차원에서 상호의존성을 갖는다. 전통적 회귀분석과는 달리 위계적 분석모형은 요인들 간의 상호의존성과 복합결합적 영향관계를 규명하는 장점이 있다. 이러한 분석 기법에 의한 결과는 보다 효율적인 TOD정책 대한의 모색에 많은 기여를 할 것으로 기대된다.

• 대한수학회지
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• 제49권4호
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• pp.855-865
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• 2012

Recently, we have introduced a group invariant, which is related to the number of elements $x$ and $y$ of a finite group $G$ such that $x{\wedge}y=1_{G{\wedge}G}$ in the exterior square $G{\wedge}G$ of $G$. This number gives restrictions on the Schur multiplier of $G$ and, consequently, large classes of groups can be described. In the present paper we generalize the previous investigations on the topic, focusing on the number of elements of the form $h^m{\wedge}k$ of $H{\wedge}K$ such that $h^m{\wedge}k=1_{H{\wedge}K}$, where $m{\geq}1$ and $H$ and $K$ are arbitrary subgroups of $G$.

• 대한안전경영과학회지
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• 제19권4호
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• pp.253-260
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• 2017

Due to dramatic changes in the trend of corporate management in economics, labor and government, companies are being asked to adapt creative and innovative organizational culture in order to keep sustainability. Under the circumstances, flexible working hour becomes one of very effective method for organization culture improvement. Recently, M company has introduced the new policy of working hours that employees can choose a couple of different time options depending on their personal situations. And it turns out to be very effective to work & life balance, increasing organizational vitality, improving efficiency of business and productivity, recruitment of core human resources, and prevention of deviation; both team and personal performance levels has significantly improved. Therefore, it is highly recommended to adapt flexible working policies for companies seeking for a long term, sustainable corporate vision.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.645-656
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• 2008

The operation of express train on the Seoul Metropolitan Subway Network is centered on the Kyungbu and Kyungin lines and the short section between Dongducheon station and Ganyung station which is 20.7km long. It is true that the needs of many customers who want to reduce their commuting hours by express train is not satisfied. This paper proposes that the operation of express trains be enlarged to Sungbuk station on Kyungwon line which comes to 34.9 km long, and to Yangsu station from Youngsan station on Jungang line. The type of operation is mixed one with high and low speed trains, which operates express train by use of existing siding tracks without improving facilities such as extra building of sidings. This pragmatic study is to apply the goal of reducing running time as express train and to suggest the selection of appropriate stops, effectivenes analysis of express train operation and formation of train diagrams to actual operation.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제26권3호
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• pp.111-131
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• 2019

We introduce (CLRg) property for hybrid pair $F:X{\times}X{\rightarrow}2^X$ and $g:X{\rightarrow}X$. We also introduce joint common limit range (JCLR) property for two hybrid pairs $F,G:X{\times}X{\rightarrow}2^X$ and $f,g:X{\rightarrow}X$. We also establish some common coupled fixed point theorems for hybrid pair of mappings under generalized (${\psi},{\theta},{\varphi}$)-contraction on a noncomplete metric space, which is not partially ordered. It is to be noted that to find coupled coincidence point, we do not employ the condition of continuity of any mapping involved therein. As an application, we study the existence and uniqueness of the solution to an integral equation. We also give an example to demonstrate the degree of validity of our hypothesis. The results we obtain generalize, extend and improve several recent results in the existing literature.

• Kyungpook Mathematical Journal
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• 제60권4호
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• pp.711-721
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• 2020

The concepts of an Amitsur ring and a hereditary Amitsur ring, which were introduced and studied by S. Tumurbat in a recent paper, are generalized. For a positive integer n, a ring A is said to be an n-Amitsur ring if γ(A[Xn]) = (γ(A[Xn]) ∩ A)[Xn] for all radicals γ, where A[Xn] is the polynomial ring over A in n commuting indeterminates. If a ring A satisfies the above equation for all hereditary radicals γ, then A is said to be a hereditary n-Amitsur ring. Characterizations and examples of these rings are provided. Moreover, new radicals associated with n-Amitsur rings are introduced and studied. One of these is a special radical and its semisimple class is polynomially extensible.

• East Asian mathematical journal
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• 제38권5호
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• pp.549-581
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• 2022

Let M be a semi-invariant submanifold with almost contact metric structure (𝜙, 𝜉, 𝜂, g) of codimension 3 in a complex space form M_n+1(c), c≠ 0. We denote by S and R_𝜉 be the Ricci tensor of M and the structure Jacobi operator in the direction of the structure vector 𝜉, respectively. Suppose that the third fundamental form t satisfies dt(X, Y) = 2𝜃g(𝜙X, Y) for a certain scalar 𝜃(≠ 2c) and any vector fields X and Y on M. In this paper, we prove that M satisfies R_𝜉S = SR_𝜉 and at the same time R_𝜉𝜙 = 𝜙R_𝜉, then M is a Hopf hypersurface of type (A) provided that the scalar curvature s of M holds s - 2(n - 1)c ≤ 0.