• Journal of the Korean Mathematical Society
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• v.39 no.4
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• pp.621-651
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• 2002

An extended Steiner triple system of order v, denoted by ESTS(v), is said to be (f, k)-rotational if it admits an automorphism consisting of exactly f fixed elements and k cycles of length (equation omitted). In this paper, we obtain a necessary and sufficient condition for the existence of (f,2)-rotational extended Steiner triple systems with f=2 and f=3.

• Bulletin of the Korean Mathematical Society
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• v.48 no.6
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• pp.1235-1243
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• 2011

In this paper, we investigate sharing value problems related to a meromorphic function f(z) and f(qz), where q is a non-zero constant. It is shown, for instance, that if f(z) is zero-order and shares two valves CM and one value IM with f(qz), then f(z) = f(qz).

• Journal of the Korean Ceramic Society
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• v.31 no.2
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• pp.201-205
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• 1994

Glasses being prepared, measurements and investigations of glass transition temperature and IR edge optical absorption have been performed for the compositions of 56ZrF4-14BaF2-6LaF3-4AlF3-(20-x)NaF-xLiF. Values for transition temperature of these glasses decrease in proportion to increasing LiF mol%(x) in the range of 0

• Journal of applied mathematics & informatics
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• v.20 no.1_2
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• pp.479-483
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• 2006

For any fixed $\lambda\leq-\frac{1}{2}$, there exists $f(\eta){\in}C^1[0,+\infty)$ which satisfies the following nonlinear boundary value problem f'+ff'+$\lambda(l-f'^2)=0$ a.e.in $(0,+\infty)$, f(0)=0, f'(0) = 0, $f'(+\infty)=1$, which arises in boundary layer theory in fluid mechanics.

• Honam Mathematical Journal
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• v.41 no.4
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• pp.813-821
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• 2019

In this paper, we investigate Hyers-Ulam-Rassias stability of a functional equation f(x + ky) + f(x - ky) - k²f(x + y) - k²f(x - y) + 2(k² - 1)f(x) + (k² + k)f(y) + (k² - k)f(-y) - 2f(ky) = 0.

• Aerospace Industry
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• v.61
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• pp.23-25
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• 1998

미국의 워싱턴포스트지는 지난 5월 12일 중동의 아랍 에미레이트(UAE)가 차세대 전투기로 F-16 80대를 구매하기로 록히드마틴사와 전격 계약하였으며 사업규모는 60억불이라고 보도하였다. 이번에 결정된 차세대 전투기의 후보기종에는 프랑스의 라팔과 유럽연합의 유로파이터, 보잉의 F-15, 록히드 마틴의 F-16이 경합하였으며, ''''97년 9월에 F-15, 유로파이터는 탈락되고 F-16과 라팔기종중에서 최종적으로 성능, 안전성 및 실전사례 평가 등을 고려 결정된 것으로 알려졌다. 본 고에서는 이번 UAE의 대량 구매를 계기로 우리공군의 주력전투기인 F-16의 과거와 현재 그리고 미래에 대해 살펴보고자 한다.

• Journal of the Korean Mathematical Society
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• v.32 no.2
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• pp.279-287
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• 1995

Let $F$ be a set of distributions on R with the topology of weak convergence, and let $A$ be the $\sigma$-field generated by the open sets. We denote by $F_1^\infty$ the space consisting of all infinite sequence $(F_1, F_2, \cdots), F_n \in F and R_1^\infty$ the space consisting of all infinite sequences $(x_1, x_2, \cdots)$ of real numbers. Take the $\sigma$-field $F_1^\infty$ to be the smallest $\sigma$-field of subsets of $F_1^\infty$ containing all finite-dimensional rectangles and take $B_1^\infty$ to be the Borel $\sigma$-field $R_1^\infty$.

• Communications of the Korean Mathematical Society
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• v.15 no.4
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• pp.675-681
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• 2000

Let f : M longrightarrow M be a homotopically periodic self-map of a closed surface M. Except for M = $S^2$, the Nielsen number N(f) and the Lefschetz number L(f) of the self-map f are the same. This is a generalization of Kwasik and Lee's result to 2-dimensional case. On the 2-sphere $S^2$, N(f) = 1 and L(f) = deg(f) + 1 for any self-map f : $S^2$longrightarrow$S^2$.

• Animal Systematics, Evolution and Diversity
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• v.15 no.1
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• pp.1-9
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• 1999

As the 3rd series of the study on the family Lecithoceridae in Sri Lanka, 11 species of the genus Frisilia Walker, 1864, are recognized. Of these, 5 species, Frisilia thapsina, F, tricrosura, F. trizeugma, F. ancylosana, and F. neacantha are described as new to science, with illustrations fo their genitalia are given.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.3
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• pp.275-281
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• 2006

In this article, we establish the stability of the orthogonally cubic type functional equation 2f(x + 2y) + 2f(x - 2y) + 2f(2x)+7[f(x)+f(-x)] = 4f(x)+8[f(x+y)+f(x-y)], $x{\bot}y$ in which ${\bot}$ is the orthogonality in the sense in the R$\ddot{a}$tz.