• Journal of the Korean Vacuum Society
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• 제10권3호
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• pp.321-327
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• 2001

Ti-Si-N films obtained by using RF reactive sputtering of targets with various Ti/Si ratios in a $N_2(Ar+N_2)$ gas mixture have been investigated in terms of films resistivity and diffusion barrier performance. The chemical bonding state of Si in the Ti-Si-N film which contained a higher Si content was in the form of amorphous $Si_3N_4$, producing increased film resistivity with increased $N_2$flow rate. Lowering the Si content in the deposited Ti-Si-N film favored the formation of crystalline TiN even at low $N_2$flow rates, and leads to low film resistivity. In addition increasing the N content led to Ti-Si-N films having a higher density and compressive stress, suggesting that the N content in the films appear to be one of the most important factors affecting the diffusion barrier characteristics. Consequently, we proposed the optimum composition in the range of 29~49 at.% of Ti, 6~20 at.% of Si, and 45~55 at.% of N for the Ti-Si-N films having both low resistivity and excellent diffusion barrier performance.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.167-176
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• 2008

Atmospheric N deposition has far-reaching impacts on forest ecosystems, including on-site impacts such as soil acidification, fertilization, and nutrient imbalances, and off-site environmental impacts such as nitrate leaching and nitrous oxide emission. Although chronic N deposition has been believed to lead to forest N saturation, recent evidence suggests that N retention capacity, particularly in the forest floor, can be surprisingly high even under high N deposition. This review aims to provide an overview of N retention processes in the forest floor and the implications of changing C-N interactions for C sequestration. The fate of available N in forest soils has been explained by the competitive balance between tree roots, soil heterotrophs, and nitrifiers. However, high rates of N retention have been observed in numerous N addition experiments without noticeable increases in tree growth and soil respiration. Alternative hypotheses have been proposed to explain the gap between the input and loss of N in N-enriched, C-limited systems, including abiotic immobilization and mycorrhizal assimilation, both of which do not require additional C sources to incorporate N in soil N pools. Different fates of N in the forest floor have different implications for C sequestration. N-induced tree growth can enhance C accumulation in tree biomass as observed across temperate regions. C loss from forests can amount to or outweigh C gain in N-saturated, declining forests, while another type of 'C-N decoupling' can have positive or neutral effects on soil C sequestration through hampered organic matter decomposition or abiotic N immobilization, respectively.

• Korean Journal of Materials Research
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• 제9권1호
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• pp.42-45
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• 1999

The room temperature optical transmission spectra of GaN /InGaN/GaN single quantum wells (SQW) and InGaN/GaN heterostructures grwon by low pressure metalorganic chemical vapor deposition have been measured. The dependence of the absorption edges of the GaN/InGaN/GaN SQW on the well width has been determined from the transmission spectra. The result shows that the absorption edge of GaN/InGaN/GaN SQW shifts towards lower energy as increasing the well width. The dependence of the absorption edges of the InGaN/GaN heterostructures on InN mole fraction has also been determined from the transmission spectra. The result is compared with calculated values obtained from Vegards's laws. Our result shows a good agreement with the calculated values.

• Journal of Nutrition and Health
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• 제28권2호
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• pp.95-106
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• 1995

The effects of various n-6/n-3 ratios(about 2, 4, 6, 8) of dietary fatty acids on various lipid levels and prostaglandin production were studied at the constant P/S ratio (1.5-1.6) in young (5 weeks old) and adult(8 months old) Sprague-Dawley rats using palm oil, safflower oil and sardine oil. The concentration of serum cholesterol tended to increase with the increasing n-6/n-3 ratio. The tendency of HDL-cholesterol levels was similar to serum cholesterol levels. These were not apparent differences between young and adults rats. Serum triglyceride levels increased according to increasing n-6/n-3 ratio in young rats. These were generally high in the adult rats compared with the young rats. Though liver cholesterol level tended to increase according to the increasing n-6/n-3 ratio in the young rats. The liver triglyceride level did not change according to the n-6/n-3 ratio. However, these levels were apparently higher in the adult than in the young rats. The fatty acid compositions of phosphatidylcholine(PC) were similar in serum and liver. The arachidonate/linoleate ratios in tissue PC were influenced by the n-6/n-3 ratio. They tended to be lower in the adult rats compared with the young rats. It was suggested that the activity of $\Delta$6-desturase was decreased by aging. Production of platelet thromboxane A2(TXA2)and aortic prostacyclin(PGI2) was not apparently influenced with n-6/n-3 ratio. Whereas the ratio of TXA2/PGI2 was the lowest value at 3.8 of n-6/n-3 ratio, expecially in the young rats. Thus this ratio seemed to be a desirable level to protect atherosclerosis. These results indicate that the lipid level and prostaglandin production were influenced not only by n-6/n-3 ratio(under constant P/S ratio) but by aging, particulary triglycerde level and arachidonic/linoleic acid ratio.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1608-1614
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• 2014

The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products.

• Journal of applied mathematics & informatics
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• 제5권3호
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• pp.859-866
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• 1998

In this paper we shall prove weak(or strong) convergence of the iterates ${\chi_n} \;and \;{y_n}$ defined by $\chi-{n+1}= \alpha_nTy_n+(1-\alpha_n)S\chi_n , y_n=\beta_nT\chi_n+(1-\beta_n)\chi_n$ for all n$\geq$1, where $\alpha_n$ and $\beta_n$ satisfy 0$\leq\alpha_n,\beta_n\leq$b<1.

• Journal of the Korean Mathematical Society
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• 제45권5호
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• pp.1393-1404
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• 2008

Let K be a nonempty closed convex subset of a Banach space E. Suppose $\{T_{n}\}$ (n = 1,2,...) is a uniformly asymptotically regular sequence of nonexpansive mappings from K to K such that ${\cap}_{n=1}^{\infty}$ F$\(T_n){\neq}{\phi}$. For $x_0{\in}K$, define $x_{n+1}={\lambda}_{n+1}x_{n}+(1-{\lambda}_{n+1})T_{n+1}x_{n},n{\geq}0$. If ${\lambda}_n{\subset}[0,1]$ satisfies $lim_{n{\rightarrow}{\infty}}{\lambda}_n=0$, we proved that $\{x_n\}$ weakly converges to some $z{\in}F\;as\;n{\rightarrow}{\infty}$ in the framework of reflexive Banach space E which satisfies the Opial's condition or has $Fr{\acute{e}}chet$ differentiable norm or its dual $E^*$ has the Kadec-Klee property. We also obtain that $\{x_n\}$ strongly converges to some $z{\in}F$ in Banach space E if K is a compact subset of E or there exists one map $T{\in}\{T_{n};n=1,2,...\}$ satisfy some compact conditions such as T is semi compact or satisfy Condition A or $lim_{n{\rightarrow}{\infty}}d(x_{n},F(T))=0$ and so on.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제15권8호
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• pp.752-758
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• 2004

This paper reports on the DC and RF characteristics of AlGaN/InGaN/GaN high electron-mobility transistors (HEMTs) grown by molecular beau epitaxy(MBE) on sapphire substrates. The devices with a 0.5 ${\mu}$m gate-length exhibited relatively flat transconductance(g$\_$m/), which results from the enhanced carrier confinement of the InGaN channel. The maximum drain current was 880 mA/mm with a peak g$\_$m/ of 156 mS/mm, an f$\_$T/ of 17.3 GHz, and an f$\_$MAX/ or 28.7 GHz. In addition to promising DC and RF results, pulsed I-V and current-switching measurements showed little dispersion in the unpassivated AlGaN/InGaN HEMTs. These results suggest that the addition of In to the GaN channel improves the electron transport characteristics as well as suppressing current collapse that is related to the surface trap states.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제18권6호
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• pp.1361-1368
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• 2014

In this paper, we analyze emddings among HFCube(n,n), HCN(n,n), HFN(n,n) with lower network cost than that of Hypercube. The results are as follows. We propose that $Q_{2n}$ can be embedded into HFCube(n,n) with dilation 5, congestion 2. HCN(n,n) and HFN(n,n) are subgraphs of HFCube(n,n). HFCube(n,n) can be embedded into HFN(n,n) with dilation 3. HFCube(n,n) can be embedded into HCN(n,n) with dilation O(n). The results will be helpful to analyze several efficient properties in each interconnection network.

• Journal of the Korean Mathematical Society
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• 제41권3호
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• pp.479-487
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• 2004

Let G be a finite group and N be a normal subgroup of G. We denote by ncc(N) the number of conjugacy classes of N in G and N is called n-decomposable, if ncc(N) = n. Set $K_{G}\;=\;\{ncc(N)$\mid$N{\lhd}G\}$. Let X be a non-empty subset of positive integers. A group G is called X-decomposable, if KG = X. In this paper we characterise the {1, 3, 4}-decomposable finite non-perfect groups. We prove that such a group is isomorphic to Small Group (36, 9), the $9^{th}$ group of order 36 in the small group library of GAP, a metabelian group of order $2^n{2{\frac{n-1}{2}}\;-\;1)$, in which n is odd positive integer and $2{\frac{n-1}{2}}\;-\;1$ is a Mersenne prime or a metabelian group of order $2^n(2{\frac{n}{3}}\;-\;1)$, where 3$\mid$n and $2\frac{n}{3}\;-\;1$ is a Mersenne prime. Moreover, we calculate the set $K_{G}$, for some finite group G.