• Honam Mathematical Journal
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• v.34 no.4
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• pp.519-531
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• 2012

Let ${\sigma}_s(N)={\sum}_{d{\mid}N}d^s$. Next, the convolution sums ${\sum}_{k<N/3}{\sigma}_1(3^mk){\sigma}_1(2^n(N-3k))$, ${\sum}_{<N/3}{\sigma}_1(2^mk){\sigma}_1(3^n(N-3k))$, etc., are evaluated for all $N{\in}\mathbb{N}$ with $m$, $n{\in}\mathbb{N}{\cup}\{0\}$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.10a
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• pp.23-23
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• 1998

Michael Reaction을 이용하여 상업적으로 이용 가능한 APS(3-aminopropyltrime thoxysilane)과 AEAPS(N-[3-(trimethoxysilyl)propy1] ethylenediamine)을 다수의 Michael acceptor(ethyl acrylate, acrylonitrile, acrylamide, 2-cyanoethyl acrylate, 2-hydroxyethyl acrylate 그리고 3-(trimethoxysilyl)propylmethacrylate)와 반응시켜 10종류의 aminosilane ([3-｛N-2-carboethoxyethyl)aminopropyl]triethoxysilane, [3-(N-2-cyanoethyl)aminopropyl] triethoxysilane, [3-(N-di-2-carboethoxyethyl) aminopropyl]triethoxysilane, [3-(N-di-2-cyanoethyl)aminopropyl]triethoxysilane, [3-(N-2-cyanoethoxypropionyl)aminopropyl] triethoxysilane, [3-(N-di-2-cyanoethoxypropionyl)aminopropyl] triethoxysilane, [3-(N-di-2-hydroxyethoxypropionyl) aminopropyl]-triethoxysilane, [3-(N-2-amidoethyl aminopropyl]triethoxysilane, ｛3-[N-(N-di-2-cyanoethyl)ethyl]aminopropyl)triethoxysilane, ｛3-[N-(3-trimethoxy-silylpropyl)-2-methylpropionyl]aminopropyl)triethoxysilane 등을 35-70% 수율로 제조하였으며, 이들의 구조는 $^1$H-NMR과 FT-IR spectroscopy를 이용하여 확인하였다.

• Journal of Nutrition and Health
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• v.28 no.2
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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.

• Journal of Aquaculture
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• v.6 no.2
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• pp.89-105
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• 1993

In order to investigate the effects of dietary n-3 highly unsaturated fatty acids (n-3HUF A) levels on growth and body composition of the Korean rockfish, six experimental diets with various levels of n-3HUFA, which were adjusted by adding squid liver oil and/or soybean oil at $8\%$ dietary lipid level, were fed to the Korean rockfish (6.2g in mean body weight) for 10 weeks. Daily weight gain, feed efficiency and nutrient retention efficiency were the lowest in the fish fed a diet containing 0% n-3HUFA. These parameters were effectively improved by supplementation with n-3HUFA, and showed linear increase up to $1.2\%$ dietary n-3HUFA level (P<0.01). There was no additional response above this level. A higher concentration of nonpolar lipids in the liver was observed for the fish fed insufficient levels of n-3HUFA in the diets. However the liver glycogen content and hepatosomatic index were slightly deareased. The lipid contents of the whole body and vicera showed significantly higher in the fish fed sufficient levels of n-3HUFA in the diets (P<0.05). The fatty acid compositions of polar lipids in the whole body and liver were affected by dietary fatty acid compositions. The contents of n-3HUFA and 18:1 in the liver increased with increasing the n-3HUFA level in the diets, while the 18:2n-6 and 18: 3n-3 decreased. These results suggest that n-3HUFA plays an essential role for normal growth of the Korean rockfish, and the requirement of n-3HUF A is around $1.2\%$ of the diet.

• Korean Journal of Materials Research
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• v.9 no.6
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• pp.577-582
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• 1999

In order to make the electroconductive $Si_3N_4$-TiN composities, the Si-Ti(N) compacts were nitrided at $1450^{\circ}C$ for 20hours, and then they were post-sintered by a gas-pressure-sintering technique at 1TEX>$1950^{\circ}C$ for 3.5 hours. As starting powders, commercial si powder of about $10\mu\textrm{m}$, two types of Ti powders of 100 and 325 mesh, and fine-sized TiN of $2.5\mu\textrm{m}$ powders were used. In the $Si_3N_4$-TiN sintered bodies used Ti powders, the relative density and fracture strength and electrical conductivity are low due to the existence of large amounts of coarse pores. However, in the $Si_3N_4$-TiN composite used TiN powder, the fracture toughness, fracture strength and electrical resistivity were $5.0MPa{\cdot}m^{1/2}$, 624MPa and $1400{\omega}cm$, respectively. The dispersion of TiN particles in the composite inhibited the growth of $Si_3N_4$ in the shape of rod and made strong strain field contrasts at the $Si_3N_4$-TiNinterfaces. It was recognized that microstructural control is required to improve the electrical conductivity and mechanical properties of $Si_3N_4$-TiN composites by dispersing TiN particles homogeneously.

• YAKHAK HOEJI
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• v.17 no.4
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• pp.223-234
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• 1973

Sixteen compounds of N-aroyl-N'-(4'-alkoxyphenyl) thiourea derivative, twenty one compounds of N-aeryl-N'(3'-hydroxy-4'-alkoxycar-bonylphenyl) thiourea derivative, three compounds of N-aeroyl-N'-.alpha.-naphthyiourea derivative and three compounds of N-cyanoacetyl-N'-aroyl thiosemicarbazide derivative were syntrhesized as potential antitubercular agent and were subjected to screening test for antitubercular activity against Mycobacterium turberculosis H/sub 37/Rv by tube dilution method in vitro. Of the fourty three eompounds, N-p-cyanobenzoyl-N'-(4'-iso-butoxyphenyl) thiourea, N-p-cyanobenzoyl-N'-(4-n-amoxyphenyl)thiourea, N-furoyl-N'-(3'-hydroxy-4'-ethoxycarbonylphenyl)thiourea, N-p-cyanobenzoyl-N'-(3'-hydroxy-4'-n-butoxycarbonylphenyl)thiourea, N-p-cyanobenzoyl-N'-(3'-hydroxy-4'-n-amoxycarbonylphenyl)thiourea, and N-5-nitrofuroyl-N'(3'-hydroxy-4"-n-amoxycarbonylphrnyl)thiourea showed the growth inhibition of M. tuberculosis H/sub 37/Rv at the coccentraction og 10.mu.g/ml, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.171-176
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• 1991

Field experiment was conducted to investigate the seasonal change in inorganic nitrogen content in grassland soil profile after urea application. Urea was applied at the levels of 0 (0N), 14 (14N), and 28 (28N) Kg N per 10a. Soil samples were taken at every 20 cm interval upto 100 cm soil depth in spring (May 26), summer (July 27), and autumn (October 18) and analysed for total and inorganic nitrogen ($NH_4-N$ and $NO_3-N$). The results obtained are as follows ; 1. In spring, the $NH_4-N$ content of ON treatment was higher than $NO_3-N$ content both in surface and subsoil. The urea application increasing both $NH_4-N$ and $NO_3-N$ contents in the surface soils and these contents decreased with soil depth. 2. In summer, increase in urea application rate elevated the $NO_3-N$ content in soil profile of 0 to 100cm and the content reached upto 42 ppm in the 28N treatment. 3. The seasonal difference in $NH_4-N$ content between summer and autumn was insignificant throughout soil profile. Soil $NO_3-N$ content in autumn were 7 and 14 ppm for 14N and 28N respectively, showing very low values compared with that of summer. 4. The ratio of inorganic nitrogen to total nitrogen increased with soil depth and with urea application rates.

• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.359-364
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• 2008

We have investigated optical and structural properties of $Al_{0.3}Ga_{0.7}N$/GaN and $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ heterostructures (HSs) grown by metal-organic chemical vapor deposition, by means of Hall measurement, high-resolution X-ray diffraction, and temperature- and excitation power-dependent photoluminescence (PL) spectroscopy. A strong GaN band edge emission and its longitudinal optical phonon replicas were observed for all the samples. At 10 K, a 2DEG-related PL peak located at ${\sim}\;3.445\;eV$ was observed for $Al_{0.3}Ga_{0.7}N$/GaN HS, while two 2DEG peaks at ${\sim}\;3.42$ and ${\sim}\;3.445\;eV$ were observed for $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ HS due to the additional $Al_{0.15}Ga_{0.85}N$ layers. Moreover, the emission intensity of the 2DEG peak was higher in $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ HS than in $Al_{0.3}Ga_{0.7}N$/GaN HS probably due to an effective confinement of the photo-excited holes by the additional $Al_{0.15}Ga_{0.85}N$ layers. The 2DEG-related emission intensity decreased with increasing temperature and disappeared at temperatures above 150 K. To investigate the origin of the new 2DEG peaks, the energy-band structure for multiple AlGaN/GaN HSs were simulated and compared with the experimental data. As a result, the observed high- and low-energy peaks of 2DEG can be attributed to the spatially-separated 2DEG emissions formed at different AlGaN/GaN heterointerfaces.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.553-557
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• 2000

Fatty acid composition of frond, spororphyll and stipe of Miyeok (Undaria pinnatifida) were extensively analyzed to evaluate a nutrient significance of n-3 polyenes, n-6 polyenes, ${\gamma}$-linolenic acid (18:3, n-6) and $\alpha$-linolenic acid (18:3, n-3). Polyenes of $\alpha$-linolenic acid (22:6, n-3), stearidonic acid (18:4, n-3), eicosapentaenoic acid (20:5, n-3) and docosahexaenoic acid (22:6, n-3) were as high as 29.69%, but ${\gamma}$-linolenic acid (18:3, n-6) was as low as 0.90% when compared to total polyenes of 44.18% in frond. The n-3 polyenes of neutural lipids, glycolipids and phospholipids were 22.40%, 35.82% and 3.53% in frond, 5.26%, 9.51% and 2.37% in stipe and 8.01%, 4.49% and 2.14% in sporophyll, respectively. These results suggest that total polyenes and n-3 polyenes in frond of Miyeok may be used as resource of functional food.

• Journal of applied mathematics & informatics
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• v.24 no.1_2
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• pp.437-448
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• 2007

Suppose K is a nonempty closed convex nonexpansive retract of a real uniformly convex Banach space E with P as a nonexpansive retraction. Let $T_1,\;T_2\;and\;T_3\;:\;K{\rightarrow}E$ be nonexpansive mappings with nonempty common fixed points set. Let $\{\alpha_n\},\;\{\beta_n\},\;\{\gamma_n\},\;\{\alpha'_n\},\;\{\beta'_n\},\;\{\gamma'_n\},\;\{\alpha'_n\},\;\{\beta'_n\}\;and\;\{\gamma'_n\}$ be real sequences in [0, 1] such that ${\alpha}_n+{\beta}_n+{\gamma}_n={\alpha}'_n+{\beta'_n+\gamma}'_n={\alpha}'_n+{\beta}'_n+{\gamma}'_n=1$, starting from arbitrary $x_1{\in}K$, define the sequence $\{x_n\}$ by $$\{zn=P({\alpha}'_nT_1x_n+{\beta}'_nx_n+{\gamma}'_nw_n)\;yn=P({\alpha}'_nT_2z_n+{\beta}'_nx_n+{\gamma}'_nv_n)\;x_{n+1}=P({\alpha}_nT_3y_n+{\beta}_nx_n+{\gamma}_nu_n)$$ with the restrictions $\sum^\infty_{n=1}{\gamma}_n<\infty,\;\sum^\infty_{n=1}{\gamma}'_n<\infty,\; \sum^\infty_{n=1}{\gamma}'_n<\infty$. (i) If the dual $E^*$ of E has the Kadec-Klee property, then weak convergence of a $\{x_n\}$ to some $x^*{\in}F(T_1){\cap}{F}(T_2){\cap}(T_3)$ is proved; (ii) If $T_1,\;T_2\;and\;T_3$ satisfy condition(A'), then strong convergence of $\{x_n\}$ to some $x^*{\in}F(T_1){\cap}{F}(T_2){\cap}(T_3)$ is obtained.