• Journal of the Korean Vacuum Society
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• v.4 no.2
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• pp.119-123
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• 1995

Bridgman 방법으로 성장한 InSe: Co 단결정의 근적외 영역에서의 광흡수 특성을 상온에서 조사하였다. 1350, 1530, 1710nm 파장영역에서 Td 대칭을 갖는 Co2+ 이온의 4A2(4F)$\longrightarrow$4T1(4F)전이에 대응되는 3개의 흡수 peak를 관측하였다. 이 미세구조는 스핀-궤도 결합효과에 의하여 분리된 Co2+ 이온의 4T1(4F) 준위의 $\Gamma$6, $\Gamma$8, $\Gamma$7+$\Gamma$8 준위와 바닥상태 4A2(4F)의 $\Gamma$8 준위 사이의 전자전이에 기인하며, 결정장이론에 의하여 잘 설명되었다.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.2
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• pp.59-75
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• 2008

Purpose: This study was performed to determine the inhibitory effect of Polygonum multiflorum(PM) on melanin synthesis in B16F10. Methods: The Inhibitory effects of Polygonum multiflorum(PM) on melanin synthesis were determined by in-vitro assay. To elucidate inhibitory effects of Polygonum multiflorum on melanin synthesis, we determined the melanin release and melanin production in B16F10. And to investigate the action mechanism, we assessed the gene expression of tyrosinase, TRP-1, TRP-2, MMP-2, PKA, PKC, ERK-1 ERK-2, AKT-1, MITF in B16F10. Results: 1. PM inhibited melanin-release, melanin production in B16F10. 2. PM inhibited tyrosinase activity in vitro and in B16F10. 3. PM suppressed the expression of tyrosinase, TRP-1 in B16F10. 4. PM suppressed the expression of PKA in B16F10. 5. PM suppressed the expression of ERK-1, ERK-2, AKT-1 in B16F10. 6. PM suppressed the expression of MITF in B16F10. Conclusion: From these results, it may be concluded that PM possesses the antimelanogenetic effects.

• Phonetics and Speech Sciences
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• v.10 no.3
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• pp.9-18
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• 2018

This paper presents an acoustic and phonological study of the alveolar flaps in American English. Based on the Buckeye Corpus, the flapping tokens produced by twenty men are analyzed at both lexical and post-lexical levels. The data, analyzed with Pratt speech analysis, include duration, F2 and F3 in voicing during the flap, as well as duration, F1, F2, F3, and f0 in the adjacent vowels. The results provide evidence on two issues: (1) The different ways in which voiced and voiceless alveolar stops give rise to neutralized flapping stops by following lexical and post-lexical levels, (2) The extent to which the vowel features (height, frontness, and tenseness) affect flapping sounds. The results show that flaps are affected by pre-consonantal vowel features at the lexical as well as post-lexical levels. Unlike previous studies, this study uses the Praat method to distinguish flapped from unflapped tokens in the Buckeye Corpus and examines connections between the lexical and post-lexical levels.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.179-184
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• 1981

This paper has been prepared to compare the safety factor of Fellenius method and Bishop method which are most frequantly utilized for stability analysis of dam and natural slope. The results are as follows. 1. Safety factor obtained by Bishop method shows 11-29% higher in steady seepage state and 46-57% higher in no seepage flow than the one by Fellenius. 2. The ratio of safety factor between no seepage flow and seepage flow ($F_1-F_2/F_2$) increases as the slope becomes flatter. 3. The ratio of safety factor between Bishop method and Fellenius ($F_B-F_F/F_F$) decreases as the slope becomes flatter.

• Korean Journal of Mathematics
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• v.28 no.2
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• pp.159-168
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• 2020

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 + k³)f(y) + (k² - k³)f(-y) - 2f(ky) = 0.

• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1147-1165
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• 2010

In this paper we compare a torsion free sheaf F on $P^N$ and the free vector bundle $\oplus^n_{i=1}O_{P^N}(b_i)$ having same rank and splitting type. We show that the first one has always "less" global sections, while it has a higher second Chern class. In both cases bounds for the difference are found in terms of the maximal free subsheaves of F. As a consequence we obtain a direct, easy and more general proof of the "Horrocks' splitting criterion", also holding for torsion free sheaves, and lower bounds for the Chern classes $c_i$(F(t)) of twists of F, only depending on some numerical invariants of F. Especially, we prove for rank n torsion free sheaves on $P^N$, whose splitting type has no gap (i.e., $b_i{\geq}b_{i+1}{\geq}b_i-1$ 1 for every i = 1,$\ldots$,n-1), the following formula for the discriminant: $$\Delta(F):=2_{nc_2}-(n-1)c^2_1\geq-\frac{1}{12}n^2(n^2-1)$$. Finally in the case of rank n reflexive sheaves we obtain polynomial upper bounds for the absolute value of the higher Chern classes $c_3$(F(t)),$\ldots$,$c_n$(F(t)) for the dimension of the cohomology modules $H^iF(t)$ and for the Castelnuovo-Mumford regularity of F; these polynomial bounds only depend only on $c_1(F)$, $c_2(F)$, the splitting type of F and t.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.187-195
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• 1992

This study carried out to investigate selection response of pure line population of layer chicken. Data for two layer pure line of Single Comb White Leghorn were collected from 1986 to 1991. Primary selection criteria were egg number to 270 days of age (EN270), egg weight(BW270), body weight (BW270) at 270 days of age and the days of the 1st egg(SM). The results obtained in this study are summarized as follows ; 1. Mean phenotypic values of two strains were decreased by 1.94 day(K), 1.320ay(F) for SM and increased by 0.09g(K), -0.05g(F) for EW 270 and 0.56(K), -0.78(F) for EN270. 2. The ratio of a realized selection differential to expected selection differentials for SM (sexual maturity), EW 270, and BW 270 were not significantly decreased during 5 generations. 3. Heritability were estimated from sib analysis. The means of estimates were 0.28(F), 0.39(K) for BW270, and 0.25(F), 0.29(K) for EN270 and 0.51(F), 0.48(K) for EW270. 4. The genetic gains were estimated by method of selection index in retrospect on the basis of selection differentials. EN270 and EW270 were found to increase by 2.01(F), 2.25(K) and 0.54 (F), 0.65(K) per generation.

• Journal of Sericultural and Entomological Science
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• v.53 no.1
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• pp.12-18
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• 2015

This study was conducted to consider practical use of F2 hybrid and intervariety crossing for the improvement of silkworm eggs export and silkworm eggs manufacture. Now Kumokjam and Baegokjam come into wide use to sericulture farmers but comparison test of F1, F2 hybrid and intervariety have not been done. We weighed against the productivity among economical character. While larval period of F2 among them is most long time, pupation percentage and cocoon yield per 10,000 3rd molted larvae are lower than intervariety. With comparing F2 and intervariety, single cocoon weight of F2 is lower 9 ~ 21% than intervariety, and cocoon shell weight of F2 was lower 10 ~ 18% than intervariety. By number of cocoons per liter, F2 hybrid was lower and more irregular size than intervariety. In coparison with number of egg laid, F2 hybrid Baegokjam was 655 ea (14%) and Kumokjam 625 ea (40%) more than F1 hybrid. Also, F2 hybrid for filament grade went down than F1 hybrid. The advantage of egg production in F2 hybrid can reduce costs because there is no necessity for sex discrimination and germination control. But besides increase of number of egg laid, the productivity including economical characters was greatly lowered. Except for being a lot of laying eggs, cocoon productivity of the F2 was greatly reduced by degeneration of practical traits. Therefore the further studies are needed in order to increase utilization value of the F2 hybrid silkworm.

• Bulletin of the Korean Mathematical Society
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• v.51 no.5
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• pp.1281-1289
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• 2014

In this paper, we consider the differential equation $$F^{\prime}-Q_1=Re^{\alpha}(F-Q_2)$$, where $Q_1$ and $Q_2$ are polynomials with $Q_1Q_2{\neq}0$, R is a rational function and ${\alpha}$ is an entire function. We consider solutions of the form $F=f^n$, where f is an entire function and $n{\geq}2$ is an integer, and we prove that if f is a transcendental entire function, then $\frac{Q_1}{Q_2}$ is a polynomial and $f^{\prime}=\frac{Q_1}{nQ_2}f$. This theorem improves some known results and answers an open question raised in [16].

• Journal of applied mathematics & informatics
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• v.33 no.1_2
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• pp.173-183
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• 2015

A radio k-labeling f of a graph G is a function f from V (G) to $Z^+{\cup}\{0\}$ such that $d(x,y)+{\mid}f(x)-f(y){\mid}{\geq}k+1$ for every two distinct vertices x and y of G, where d(x, y) is the distance between any two vertices $x,y{\in}G$. The span of a radio k-labeling f is denoted by sp(f) and defined as max$\{{\mid}f(x)-f(y){\mid}:x,y{\in}V(G)\}$. The radio k-labeling is a radio labeling when k = diam(G). In other words, a radio labeling is an injective function $f:V(G){\rightarrow}Z^+{\cup}\{0\}$ such that $${\mid}f(x)=f(y){\mid}{\geq}diam(G)+1-d(x,y)$$ for any pair of vertices $x,y{\in}G$. The radio number of G denoted by rn(G), is the lowest span taken over all radio labelings of the graph. When k = diam(G) - 1, a radio k-labeling is called a radio antipodal labeling. An antipodal labeling for a graph G is a function $f:V(G){\rightarrow}\{0,1,2,{\ldots}\}$ such that $d(x,y)+{\mid}f(x)-f(y){\mid}{\geq}diam(G)$ holds for all $x,y{\in}G$. The radio antipodal number for G denoted by an(G), is the minimum span of an antipodal labeling admitted by G. In this paper, we investigate the exact value of the radio number and radio antipodal number for the circulant graphs G(4k + 2; {1, 2}).