• Journal of Information Technology Services
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• v.1 no.1
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• pp.45-55
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• 2002

This paper suggests a new approach to IT project management based on a regular project meeting results to consider the recent project environment. The greater part of recent IT projects are related to e-business transformation. Transforming to e-business is a new problem very different from those they have been worked, in several point of views. Under e-business era, therefore any IT project is being implemented in more complex, dynamic and uncertain environment than traditional. That is, project leaders must consider more factors to control projects including resources, quality, risks, and technologies, and human resources. The project organizations and software corporations thus need to develop and establish new concepts or methodologies to manage e-business projects. In this point of view, an entropy model in this study is introduced for estimating and managing the uncertainty in project control using multi-attributes of project meeting. This paper proposes a new frame work based on entropy model using project meeting results to consider eIT project environment with a small pilot study.

• Journal of the Korean Mathematical Society
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• v.55 no.1
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• pp.73-82
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• 2018

In this article we consider certain types of nonlinear matrix equations including the stochastic rational Riccati equation and show the existence and uniqueness of the positive definite solution by using Bhaskar-Lakshmikantham's coupled fixed point theorem.

• Communications of the Korean Mathematical Society
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• v.29 no.1
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• pp.195-204
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• 2014

We consider a functional difference equation and use fixed point theory to analyze the stability of its zero solution. In particular, our study focuses on the nonlinear delay functional difference equation x(t + 1) = a(t)g(x(t - r)).

• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.92-101
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• 1997

In this paper, modeling methods for 2D joints are proposed. Earlier methods for modeling 2D joints that use geometric relationships may not consider irregularities or dynamic effects of joints. In any case, it is important to consider irregularities or dynamic effects. To consider those, methods that use dynamic contacts are proposed. With the method, 2D joints that have irregularities or dynamic effects amy be model- ed and analyzed. 2D joints that are developed are revolute, translational, gear and point-follower joint.

• Communications of the Korean Mathematical Society
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• v.24 no.3
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• pp.361-366
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• 2009

In this paper we consider constructive function triples on the real numbers $\mathbb{R}$ and on (not necessarily commutative) integral domains D which permit the construction of a multitude of d-algebras via these constructive function triples. At the same time these constructions permit one to consider various conditions on these d-algebras for subsets of solutions of various equations, thereby producing geometric problems and interesting visualizations of some of these subsets of solutions. In particular, one may consider what notions such as "locally BCK" ought to mean, certainly in the setting provided below.

• Bulletin of the Korean Mathematical Society
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• v.47 no.1
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• pp.73-79
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• 2010

A pair of point vortices of the same strength but opposite sign is called a vortex dipole. We consider the limiting case where two vortices approach infinitely close while the ratio of the strength to the distance kept constant. The motion of such point vortex dipole on the ellipsoid of revolution is investigated geometrically to conclude that the trajectory draws a geodesic up to the leading order of perturbation, whose direction is determined by the initial orientation of the dipole. Related issues are also remarked.

• Bulletin of the Korean Mathematical Society
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• v.55 no.6
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• pp.1921-1930
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• 2018

We consider a functional difference equation and use fixed point theory to obtain necessary and sufficient conditions for the asymptotic stability of its zero solution. At the end of the paper we apply our results to nonlinear Volterra infinite delay difference equations.

• Journal of the Korean Data and Information Science Society
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• v.16 no.3
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• pp.657-663
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• 2005

Under the minimum risk point estimation formulation of Robbins(1959), we consider the sequential point estimation problem for normal population $N({\theta},\;{\theta})$ with unknown parameter ${\theta}$. In the case of completely unknown ${\theta}$, Stein's(1945) two-stage procedure is known to enjoy the consistency property, but it is not even first-order efficient. In the case when ${\theta}>{\theta}_L\;where\;{\theta}_L(>0)$ is known, the revised two-stage procedure is shown to enjoy all the usual second-order properties.

• Korean Management Science Review
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• v.20 no.2
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• pp.179-196
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• 2003

Function point model is the international standard method to measure the software size which is one of the most important factors to determine the software development cost. Function point model can successfully be applied only when the detailed specification of users' requirements is available. In the domestic public sector, however, the budgeting for software projects is carried out before the requirements of softwares ere specified in detail. Therefore, an efficient function point estimation method is required to apply function point model at the early stage of software development projects. The purpose of this paper is to compare various function point estimation methods and analyse their accuracies in domestic software projects. We consider four methods : NESMA model, ISBSG model, the simplified function point model and the backfiring method. The methods are applied to about one hundred of domestic projects, and their estimation errors are compared. The results can used as a criterion to select an adequate estimation model for function point counts.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.1
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• pp.1-17
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• 2013

In this paper, firstly, 'value', 'vertices', 'height' are discussed, which are used in the multiple contexts. Then 'sketch', 'mental math', 'zero point oneth place/zero point zero oneth place/zero point zereo zero oneth place', 'number of place', 'natural number part/decimal part' are discussed, which are not used consistently. Finally, middle school mathematics terms 'distance', 'number line', 'the value of the expression' are discussed which are used in elementary school mathematics textbooks/workbooks. From these discussions, the following four suggestions are proposed as conclusions. First, as a mathematical term 'value' and 'distance' should be emphasized. As 'distance' is a middle school term, there is a need to consider the 'height' as 'the length of the line segment' instead of 'distance'. Second, 'number of place' which can be replaced with other suitable term, 'the value of the expression' including 'value of $20{\times}4$', 'natural number part/decimal part', 'vertex of pyramid/vertex of cone', 'mental math' should not be used. Third, there is a need to consider the use of 'mixed decimal' and 'proper decimal'. In addition, there is a need to expand the use of 'sketch'. Fourth, there is a need to consider the confirmation of 'number line' as an elementary school mathematics term. In addition, there is a need to consider to specify that 'decimal first place', 'decimal second place', 'decimal third place' can be used equivalently with 'zero point oneth place', 'zero point zero oneth place', 'zero point zereo zero oneth place' respectively.