• Journal of the Korean Mathematical Society
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• v.32 no.3
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• pp.471-482
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• 1995

A complex n-dimensional Kaehlerian manifold of constant holomorphic sectional curvature c is called a comples space form, which is denoted by $M_n(c)$. A complete and simply connected complex space form consists of a complex projective space $P_nC$, a complex Euclidean space $C^n$ or a complex hyperbolic space $H_nC$, according as c > 0, c = 0 or c < 0. The induced almost contact metric structure of a real hypersurface M of $M_n(c)$ is denoted by $(\phi, \zeta, \eta, g)$.

• Journal of the Korean Magnetics Society
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• v.7 no.5
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• pp.250-257
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• 1997

The microstructure and magnetic properties of Fe-Nb-B-N thin film alloys, which produced by rf magnetron sputtering method in $Ar+N_2$ mixed gas atmosphere, were investigated. The $Fe_{70}Nb_{14}B_{11}N_5$ films, annealed at 59$0^{\circ}C$, exhibit soft magnetic properties: $4{\pi}M_s=16.5kG$ , $H_c=0.13Oe$ and ${\mu}_{eff}$ (1~10 MHz)=5, 000. The frequency stability of the Fe-Nb-B-N films has also been found to be good up to 10 MHz. The Fe-Nb-B-N thin film alloys annealed at 59$0^{\circ}C$ consist of three phase; fine crystalline $\alpha$-Fe phase with grain size of about 5~10 nm, Nb-B rich amorphous phase and Nb-nitride precipitates with the size of less than 3 nm. Annealed Fe-Nb-B films have two phases; $\alpha$-Fe grains with the size of about 10 nm and Nb-B rich amorphous phase. The addition of N decreased $\alpha$-Fe grain size due to the precipitation of NbN. The good magnetic properties of the Fe-Nb-B-N film alloys are due to fine $\alpha$-Fe grains resulting from the precipitation of NbN.

• The Pure and Applied Mathematics
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• v.30 no.3
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• pp.337-345
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• 2023

Different versions of the boundary Schwarz lemma for the 𝒩 (𝜌) class are discussed in this study. Also, for the function g(z) = z+b₂z²+b₃z³+... defined in the unit disc D such that g ∈ 𝒩 (𝜌), we estimate a modulus of the angular derivative of g(z) function at the boundary point 1 ∈ 𝜕D with g'(1) = 1 + 𝜎 (1 - 𝜌), where ${\rho}={\frac{1}{n}}{\sum\limits_{i=1}^{n}}g(c_i)={\frac{g^{\prime}(c_1)+g^{\prime}(c_2)+{\ldots}+g^{\prime}(c_n)}{n}}{\in}g^{\prime}(D)$ and 𝜌≠1, 𝜎 > 1 and c₁, c₂, ..., c_n ∈ 𝜕D. That is, we shall give an estimate below |g"(1)| according to the first nonzero Taylor coefficient of about two zeros, namely z = 0 and z ≠ 0. Estimating is made by using the arithmetic average of n different derivatives g'(c₁), g'(c₂), ..., g'(c_n).

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.627-633
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• 1995

This experiment was designed to evaluate the effect of various dietary vitamin $B_6$ levels on conversion from linoleic acid to arachidonic acid in various tissues in growing chicks. Growing chicks were fed the purified diet containing 7% safflower oil with different levels of vitamin $B_6$ (0, 4, 8, 40, 80 mg per kg diet) for 14 days. Feed intake and weight gain in chicks fed the vitamin $B_6$-free diet were markedly depressed. Esterified and free cholesterol concentrations in serum were significantly higher, while the serum triglyceride concentration was significantly lover in chicks fed the vitamin $B_6$-free diet compared to that fed diets with vitamin $B_6$. The liver triglyceride content was also lower in chicks fed the vitamin $B_6$-free diet. The liver and serum cholesterol ester fractions in chicks fed the vitamin $B_6$-free diet showed higher rate of $C_{18:2n6}$ and lower rates of $C_{18:3n6}$, $C_{20:3n6}$ and $C_{20:4n6}$ as compared with vitamin $B_6$ fed groups. In serum phospholipid fraction of chicks fed the vitamin $B_6$-free diet, rates of $C_{20:3n6}$ and $C_{20:4n6}$ were markedly lower. As dietary vitamin $B_6$ level was increased, the rate of $C_{20:4n6}$ was slightly increased, although it was statistically not significant. The fatty acid compositions of adipose tissue showed almost the same pattern as those in liver and serum. This result suggests that the desaturation of $C_{18:2n6}$ to $C_{18:3n6}$, elongation to $C_{20:3n6}$ or both steps might be impaired by vitamin $B_6$ deficiency in growing chicks.

• Textile Coloration and Finishing
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• v.13 no.5
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• pp.24-24
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• 2001

Kinetics and mechanism for alkaline hydrolysis of C. I. Disperse Blue 79(B-79) which is 4-N, N-diacetoxyethyl-2-acylamino-5-ethoxy -2′-bromo-4′,6′-dinitroazobenzene were investigated. The color strength of B-79 in acetone/water solutions of various NaOH concentrations decreased continuously. The hydrolysis rate of B-79 increased with increasing alkali concentration and appeared following first order reaction. The observed rate constants for various concentrations of B-79 showed similar values, and B-79 was hydrolyzed by first order reaction for dye concentration. Therefore, it was confirmed that the overall reaction follow second order kinetics and proceed via S/sub n/2 reaction. From the study on kinetics and spectrometric analysis, it was proposed that the rate determining step of the hydrolysis reaction of B-79 is the nucleophilic substitution reaction - that is the reaction of the rapid attack of $OH^{-}$ on the carbon atom, which is in acceptor ring, adjacent to azo group to break the C-N bond. And it was also found that the final hydrolysis products of B-79 include both the acceptor ring in the form of sodium salt and the donor ring possessing 4-N,N-dihydroxyethyl group converted from 4-N,N-diacetoxyethyl group.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.173-174
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• 2007

반도체 소자가 발달함에 따라서 박막은 더욱 다층화 되고 그 두께는 줄어들고 있다. 따라서 소자의 초고집적화를 위해서는 각 박막의 두께를 더욱 작게 하여야 한다. 또한 반도체 소자 제조 공정에서는 Si 기판과 금속 박막간의 확산이 커다란 문제로 부각되어 왔다. 특히 Cu는 높은 확산성에 의하여 Si 기판과 접합에서 많은 확산에 의한 문제가 발생하게 되며, 또한 선폭이 줄어듦에 따라 고열이 발생하여 실리콘으로 spiking이 발생하게 된다. 이러한 확산을 방지하기 위하여 금속 배선과 Si기판 사이에는 필연적으로 확산방지막을 삽입하게 되었다. 기존의 연구에서는 $1000\;{\AA}$의 W-B-C-N 확산방지막을 제작하여 연구하였다. 이 논문에서는 Cu의 확산을 방지하기 위한 W-B-C-N 확산방지막을 다양한 두께로 제작하여 그 특성을 확인하여 초고집적화를 위한 더욱 얇은 두께의 W-B-C-N 확산방지막에 대하여 연구하였다. W-B-C-N 확산방지막의 두께 변화에 대한 특성을 확인하기 위하여 $900^{\circ}C$까지 열처리 한 후 그 면저항을 측정하였다.

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.85-96
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• 2000

Four new species of predatory nematodes belonging to the Actinolaimoidea, Dorylaimida are described. Neoactinolaimus gosungensis n. sp. is 2.2-2.4 mm long, b = 4.3-4.9; c = 10.7-11.2; species 60-62 ${\mu}{\textrm}{m}$ long and is distinguishable by low lip region, asymmetrical odontostyle and its wider lumen. Egtitus arcuatus n. sp. is 1.5-1.8 mm long, b = 3.6-4.2; c = 14-15 and is characterized by having dorsally arcuate odontostyle and presence of cardiac glands at base of oesophagus. Paractinolaimus tuberculantus n. sp. is 1.9-2.5 mm long, b = 3.3-4.0, c = 7.2-8.8, spicules 66-69 ${\mu}{\textrm}{m}$ long and is unique in having coiled body posture and a tubercle at the base of oesophagus. Carcharolaimus koriensis n. sp. is 1.7-1.9 mm long, b = 3.6-4.5, c = 65-76 and is characterized by having very thick body cuticle and larger odontostyle aperture.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.121-130
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• 2016

An ansemble of N players arranged in a circle play a spatially dependent Parrondo game B. One player is randomly selected to play game B, which is based on the toss of a biased coin, with the amount of the bias depending on states of the selected player's two nearest neighbors. The player wins one unit with heads and loses one unit with tails. In game A' the randomly chosen player transfers one unit of capital to another player who is randomly chosen among N - 1 players. Game A' is fair with respect to the ensemble's total profit. The games are said to exhibit the Parrondo effect if game B is losing and the random mixture game C is winning and the reverse-Parrondo effect if game B is winning and the random mixture game C is losing. We compute the exact mean profits for games B and C by applying a state space reduction method with lumped Markov chains and we sketch the Parrondo and reverse-Parrondo regions for $3{\leq}N{\leq}6$.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2045-2050
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• 2011

Using first principles density functional theory the formation energies of various binary compounds of lithium graphite and its homologues were calculated. Lithium and graphite react to form $Li_1C_6$ (+141 mV) but not form $LiC_4$ (-143 mV), $LiC_3$ (-247 mV) and $LiC_2$ (-529 mV) because they are less stable than lithium metal itself. Properties of structure and reaction potentials of $C_5B$, $C_5N$ and $B_3N_3$ materials as iso-structural graphite were studied. Boron and nitrogen substituted graphite and boron-nitrogen material as a iso-electronic structured graphitic material have longer graphene layer spacing than that of graphite. The layer spacing of $Li_xC_6$, $Li_xC_5B$, $Li_xC_5N$ materials increased until to x=1, and then decreased until to x=2 and 3. Nevertheless $Li_xB_3N_3$ has opposite tendency of layer spacing variation. Among various lithium compositions of $Li_xC_5B$, $Li_xC_5N$ and $Li_xB_3N_3$, reaction potentials of $Li_xC_5B$ (x=1-3) and $Li_xC_5$ (x=1) from total energy analyses have positive values against lithium deposition.

• Textile Coloration and Finishing
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• v.13 no.5
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• pp.312-319
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• 2001

Kinetics and mechanism for alkaline hydrolysis of C. I. Disperse Blue 79(B-79) which is 4-N, N- diacetoxyethyl -2- acylamino-5-ethos y -2'-bromo-4',6'-dinitroazobenzene were investigated. The color strength of B-79 in acetone/water solutions of various NaOH concentrations decreased continuously. The hydrolysis rate of B-79 increased with increasing alkali concentration and appeared following first order reaction. The observed rate constants for various concentrations of B-79 showed similar values, and B-79 was hydrolyzed by first order reaction for dye concentration. Therefore, it was confirmed that the overall reaction follow second order kinetics and proceed via $S_N2$ reaction. From the study on kinetics and spectrometric analysis, it was proposed that the rate determining step of the hydrolysis reaction of B-79 is the nucleophilic substitution reaction - that is the reaction of the rapid attack of OH- on the carbon atom, which is in acceptor ring, adjacent to auto group to break the C-N bond. And it was also found that the final hydrolysis products of B-79 include both the acceptor ring in the form of sodium salt and the donor ring possessing 4-N,N-dihydroxyethyl group converted from 4-N, N-diacetoxyethyl group.