• East Asian mathematical journal
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• v.33 no.2
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• pp.199-216
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• 2017

A rational number as operator is eventually that it is considered a mapping. Depending on how selecting domain (the target of operation by rational number) and codomain (including the results of operations by rational number), it is possible to see the rational in two aspects. First, rational numbers can be deal with functions if we choose the target of operation by rational number as a number field containing rationals. On the other hand, if we choose the target of operation by rational number as integral domain $\mathbb{Z}$, then rational numbers can be regarded as partial functions on $\mathbb{Z}$. In this paper, we regard the rational numbers with a view of partial functions, we investigate the theoretical background of the relationship between the multiplication of rational numbers and the composition of rational numbers as operators.

• East Asian mathematical journal
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• v.19 no.2
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• pp.251-259
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• 2003

The concepts of t-rational extensions and t-essential extensions of modules, where t a preradical for R-Mod, are introduced. The structures of such extensions are determined. Relations between maximal t-rational extensions and other concepts of modules are studied.

• Proceedings of the CALSEC Conference
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• 2002.01a
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• pp.470-472
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• 2002

개발은 신속하게, 코드는 믿을 수 있게 개발하기 위해서 필요한 사항들 찾기 어려운 오류를 자동으로 찾게 함 성능의 병목부분을 표시 테스트 되지 않은 코드를 찾아 줌 이것을 가능하게 하는 툴 = Rational PurifyPlus Rational PurifyPlus는 하나의 패키지 형식으로 업계 최고의 세 가지 제품으로 구성 Rational Purify Rational Quantify Rational PureCoverage(중략)

• Korean Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.135-139
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• 1998

The hodograph, which are usually defined as the derivative of parametric curve or surface, is useful far various geometric operations. It is known that the hodographs of Bezier curves and surfaces can be represented in the closed form. However, the counterparts of rational Bezier curves and surface have not been discussed yet. In this paper, the equations are derived, which are the closed form of rational Bezier curves and surfaces. The hodograph of rational Bezier curves of degree n can be represented in another rational Bezier curve of degree 2n. The hodograph of a rational Hazier surface of degree m×n with respect to a parameter can be also represented in rational Bezier surface of degree 2m×2n. The control points and corresponding weight of the hodographs are directly computed using the control points and weights of the given rational curves or surfaces.

• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.689-701
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• 2021

The purpose of this paper is to optimize the number of source places required for the unique representation of the destination using the tools of graph theory. A subset S of vertices of a graph G is called a rational resolving set of G if for each pair u, v ∈ V - S, there is a vertex s ∈ S such that d(u/s) ≠ d(v/s), where d(x/s) denotes the mean of the distances from the vertex s to all those y ∈ N[x]. A rational resolving set is called minimal rational resolving set if no proper subset of it is a rational resolving set. In this paper we study varieties of minimal rational resolving sets defined on the basis of its complements and compute the minimum and maximum cardinality of such sets, respectively called as lower and upper rational metric dimensions for power of a path P_n analysing various possibilities.

• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.717-734
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• 1996

For a scalar rational function, the spectral data consisting of zeros and poles with their respective multiplicities uniquely determines the function up to a nonzero multiplicative factor. But due to the richness of the spectral structure of a rational matrix function, reconstruction of a rational matrix function from a given spectral data is not that simple.

• Communications of the Korean Mathematical Society
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• v.12 no.4
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• pp.851-854
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• 1997

In this paper we will show that the pure subring R of F-rational ring S is F-rational when R is a one-dimensional ring, or S is a Gorenstein ring. And we will give a condition that a pure subring of an F-rational ring is to be F-rational.

• Journal of the Korean Home Economics Association
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• v.46 no.9
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• pp.7-19
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• 2008

This research aims to analyze rational decision behavior in different stages of purchasing for consumers buying household appliance goods and deals with differences in socio-demographic features and relevant variables among completely rational, intermediatedly rational, and irrational groups as well as variables differentiating those groups. First, one third of purchasers for Kimchi refrigerators was the rational consumer while a half of purchasers for side-by-side refrigerators and washing machines was. Second, there was no significant differences in satisfactions levels after purchase between rational and irrational groups among purchasers of side-by-side refrigerators but between completely and intermediately rational groups in the case of Kimchi refrigerators. Rational groups of consumers for Tromm washing machines rely on various places for purchase and also show the high level of intention for repurchase. Third, in studies of variables differentiating rationality in purchase behavioral patterns of consumers, rational choices turn out to prevail (1) among purchasers of married, college graduated, employers, and high income in the case of side-by-side refrigerators, (2) among buyers of male, old-aged, college graduated, non-employers, low, income, and hurrying to purchase in the case of Kimchi refrigerators, and (3) among buyers of old-aged, high income, not hurrying to purchase, and visiting numerous stores in the case of Tromm washing machines.

• Health Policy and Management
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• v.9 no.3
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• pp.53-69
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• 1999

In this study. we present a modified rational addiction model which incorporates social-psychological factors. This is done through a utility function which includes social-psychological factors as its component. We apply this model to a cigarette consumption function in Korea using the data from the Korean Household Panel Study(KHPS). The results provide relatively strong support for the rational addiction model. However. the impact of social-psychological factors and the short-run and long-run price elasticities are statistically insignificant.

• Bulletin of the Korean Mathematical Society
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• v.43 no.3
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• pp.645-652
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• 2006

The purpose of this paper is to describe some characterizations on rational and f-rational extensions of modules, to determine the forms of f-rational extensions of given f-torsion free module for a left exact radical t and investigate the maximal t-rational extensions of modules.