• 한국경영과학회지
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• 제7권1호
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• pp.51-57
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• 1982

During the course of history, more and more reliable birth control methods have become available. Hence, to a certain degree, the possibility of avoiding any or additional children, and of spacing the family building process has arisen. The advancement of six predetermination technology, whereby couples can influence the sex of their children, gives couples, another decision variable. Assuming a rational acting couple, we present a general decision-theoretic model which describes the family building process and its optimization through maximizing the expected utility concerning the spacing, ordering, sex, and number of their children.

• 대한수학회논문집
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• 제22권2호
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• pp.183-194
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• 2007

For an irreducible binomial polynomial $f(x)=x^n-b{\in}K[x]$ with a field K, we ask when does the mth iteration $f_m$ is irreducible but $m+1th\;f_{m+1}$ is reducible over K. Let S(n, m) be the set of b's such that $f_m$ is irreducible but $f_{m+1}$ is reducible over K. We investigate the set S(n, m) by taking K as the rational number field.

• 대한수학회지
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• 제40권2호
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• pp.169-177
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• 2003

Recently, K. Watanabe Showed that the Hilbert-Kunz multiplicity of a toric ring is a rational number. In this paper we give an explicit formula to compute the Hilbert-Kunz multiplicity of two-dimensional toric rings. This formula also shows that the Hilbert-Kunz multiplicity of a two-dimensional non-regular toric ring is at least 3/2.

• 대한수학회지
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• 제49권1호
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• pp.49-67
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• 2012

In this paper we give asymptotic formulas for the number of ${\ell}$-cyclic extensions of the rational function field $k=\mathbb{F}_q(T)$ with prescribe ${\ell}$-class numbers inside some cyclotomic function fields, and density results for ${\ell}$-cyclic extensions of k with certain properties on the ideal class groups.

• Journal of Communications and Networks
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• 제16권4호
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• pp.458-464
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• 2014

In the future, an increasing number of heterogeneous networks will be connected with each other. Each of them has its own interest. Existing systems lack good incentive mechanisms to attract more networks to participate in cooperations. In this paper, we design an auction-based incentive mechanism for routing protocols applied in heterogeneous networking which is computationally efficient, individually rational, profitable, and truthful. Through several simulations, we evaluate the performance and validate the properties of our mechanism.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제18권2호
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• pp.141-155
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• 2011

We compute zeta functions of 1-solenoids. When our 1-solenoid is nonorientable, we compute Artin-Mazur zeta function and Lefschetz zeta function of the 1-solenoid and its orientable double cover explicitly in terms of adjacency matrices and branch points. And we show that Artin-Mazur zeta function of orientable double cover is a rational function and a quotient of Artin-Mazur zeta function and Lefschetz zeta function of the 1-solenoid.

• 전기의세계
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• 제15권5호
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• pp.6-12
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• 1966

As a power system gets complicated and the number of regulating points increases, the voltage reactive power control tends to be more complex and more difficult. In the past, we took only the voltage regulation into account for this voltage control problem. pay attention not only to the voltage regulation but also to the rational system operation which minimizes transmission losses. Considering the rehuirements mentioned above we aim developing a method of coordination of these regulating equipments and also present some preliminary discussions aboutcomputer control of power systems which is now frequently available with the progress of digital computer technique.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.513-516
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• 2008

The development of crash cushions is finally completed by full-scale vehicle crash tests. Since the current development of crash cushions is achieved by numerous repeated full-scale vehicle crash tests based on empirical and irrational methods, it requires a great amount of costs. In this research, the more rational procedure based on prototype design by static tests and computer simulation is suggested and it can minimize the number of full-scale vehicle crash tests.

• 대한수학회논문집
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• 제37권4호
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• pp.1259-1267
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• 2022

In this paper we present a full circle approximation method using parametric polynomial curves with algebraic coefficients which are curvature continuous at both endpoints. Our method yields the n-th degree parametric polynomial curves which have a total number of 2n contacts with the full circle at both endpoints and the midpoint. The parametric polynomial approximants have algebraic coefficients involving rational numbers and radicals for degree higher than four. We obtain the exact Hausdorff distances between the circle and the approximation curves.

• 호남수학학술지
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• 제43권4호
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• pp.627-639
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• 2021

Numerical techniques are used to determine the radius of convexity of the starlike functions related to cardioid shaped bounded domain. In addition, radius constants of certain starlikeness associated with right half plane of various starlike functions are computed.