• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.385-399
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• 1997

The purpose of this experiment was to determine the effects of etching with a Nd : YAG Laser on dentin, or porcelain surface on the bond strength with composite resin. The dentin specimens were devided into the following 4 groups. D1 : No treatment D2 : Etched with 10% phosphoric acid D3 : Laser etchded with 1W, 20PPs D4 : Laser etched with 2W, 20PPS The procelain specimens were devided into the following 4 groups. P1 : diamond roughened P2 : etched with HF acid P3 : Laser etched with 2W, 20PPS P4 : Laser etched with 3W, 20PPS All specimens were veneered with resin. One half of the specimens were stored in $37^{\circ}C$ water for one day and the other half were thermocycled 1000 times at temperature of $5^{\circ}C\;to\;55^{\circ}C$ at 20 seconds intervals. After that, the bonding strength of composite resin to the dentin and porcelain was measured. The surface treated state and fractured state were observed with SEM. The following results were obtained. 1. In the dentin specimens, the bond strength of group D2 was highter than that of groups D1 and D3 in the case of the specimens stored in $37^{\circ}C$ water for one day, there was a statistically significant difference between group D2 and D1, D3 (P<0.05). The bonding strength of the specimens that were thermocycled decreased in the following order : group D2,D4,D3 and then D1. 2. In the porcelain specimens, the bonding strength of groups P1,P2 were higher than that of group P3 in the case of the specimens stored in $37^{\circ}C$ water for one day (P<0.05). The bonding strength of the specimens of being thermocycled decreased in the following order : group P2,P1,P4 and then P3. 3. The groups of high bond strength had a rougher surface and a high level of microporosity with SEM findings.

• Toxicological Research
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• v.18 no.4
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• pp.331-339
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• 2002

Phenoxy compounds, 2,4-Dichlorophenol acetoxy acid (2,4-D) and 2,4-dichlorophenol (DCP), are widely used as a hormonal herbicide and intermediate for pesticide manufacturing, respectively. In order to assess the potential of these compounds as endocrine disruptors, we studied the androgenicity of them wing in vivo and in vitro androgenicity assay system. Administration of 2,4-D (50 mg/kg/day, p.o.) or DCP (100 mg/kg/day, p.o.) to rats caused an increase in the tissue weight of ventral prostate, Cowpers gland and glands penis. These increase of androgen-dependent tissues were additively potentiated when rats were simultaneously treated with low dose of testosterone (1 g/kg, s.c.). 2,4-D increased about 350% of the luciferase activity in the PC cells transiently cotransfected phAR and pMMTV-Luc at concentration of $10^{-9}$ M. In 2,4-D or DCP-treated castrated rats, testosterone 6$\beta$-hydroxylase activity was not significantly modulated even when rats were co-treated with testosterone. In vitro incubation of 2,4-D and DCP with microsomes at 50 $\mu$M inhibited testosterone 6$\beta$-hydroxylase activity about 27% and 66% in rat liver microsomes, about 44% and 54% in human liver microsomes and about 50% and 45% in recombinant CYP3A4 system, respectively. The amounts of total testosterone metabolites were reduced about 33% and 75% in rat liver microsomes, 69% and 73% in human liver microsomes and 54% and 64% in recombinant CYP3A4 by 2,4-D or DCP, respectively. Therefore, the additive androgenic effect of 2,4-D or DCP by the co-administration of the low dose of testosterone may be due to the increased plasma level of testosterone by inhibiting the cytochrome P450-mediated metabolism of testosterone. These results collectively suggested that 2,4-D and DCP may act as androgenic endocrine disrupter by binding to the androgen receptor as well as by inhibiting the metabolism of testosterone.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.759-763
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• 2011

In this paper, a dual-band T-shaped microstrip monopole antenna with a pair of slits for 2.4/5.2/5.8-GHz wireless local area networks (WLANs) is proposed. A pair of T-shaped slits is loaded on a T-shaped monopole antenna fed by microstrip line in order to obtain dual-band operation as well as to reduce the antenna size. It is demonstrated from experimental results that the proposed antenna can cover all the required bands for WLAN. The measured impedance bandwidth for VSWR<2 is about 5.7% (2.37-2.51GHz) in the lower frequency band and about 28.8% (4.76-6.35GHz) in the higher frequency band. The measured peak gains are about 1.33 dBi to 1.66 dBi in the 2.4GHz band, 3.50 dBi to 3.95 dBi in the 5.25GHz band, and 2.06 dBi to 2.34 dBi in the 5.8GHz band.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.676-686
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• 2015

A 4D light field image is represented in traditional 2D spatial domain and additional 2D angular domain. The 4D light field has a resolution limitation both in spatial and angular domains since 4D signals are captured by 2D CMOS sensor with limited resolution. In this paper, we propose a dictionary learning-based superresolution algorithm in 4D light field domain to overcome the resolution limitation. The proposed algorithm performs dictionary learning using a large number of extracted 4D light field patches. Then, a high resolution light field image is reconstructed from a low resolution input using the learned dictionary. In this paper, we reconstruct a 4D light field image to have double resolution both in spatial and angular domains. Experimental result shows that the proposed method outperforms the traditional method for the test images captured by a commercial light field camera, i.e. Lytro.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.638-643
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• 2011

The synthesis of biologically active 1H-1,4-diazepines 4a-d and 3H-1,5-benzodiazepines 5a-d in good yields, from the heterocyclization reaction of 2-(4-methylthio benzenesulfonyl)-1,3-dimethyl/1-methyl-3-phenyl/1,3-diphenyl/1-methyl-3-ethoxy propane-1,3-dione 3a-d with ethylenediamine (EDA) and o-phenylenediamine (o-PDA), respectively, in the presence of silica sulfuric acid (SSA) is described. The novel ${\beta}$-diketones/${\beta}$-ketoesters 3a-d were synthesized by the condensation reaction of 4-methylthiobenzenesulfonyl chloride 1 with various ${\beta}$-diketones/${\beta}$-ketoesters 2a-d. All structures of the newly synthesized compounds were elucidated by elemental analysis and spectral studies. The compounds 4a-d and 5a-d have been screened for antimicrobial, antifungal and anthelmintic activity.

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.132-137
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• 2003

Three cerebrosides 2, 3, and 5 and two terpene glycosides 1 and 4 have been isolated from the methanol extract of the root of Aster scaber. Their structures were determined as 3-Ο-$\beta$-D-glucuronopyranosyl-oleanolic acid methyl ester (1), (2S, 3S, 4R, 2 R, 8Z, 15 Z)-N-2 -hydroxy-15 -tetracosenoyl-1-Ο-$\beta$-D-glucopyranosyl-4-hydroxy-8-sphingenine (2), (2S, 3S, 4R, 8Z)-N-octadecanoyl-1-Ο-$\beta$-D-glucopyranosyl-4-hydroxy-8-sphingenine (3), 1$\alpha$-hydroxy-6$\beta$-Ο-$\beta$-D-glucosyl-eudesm-3-ene (4), and (2S, 3S, 4R, 2 R, 8Z)-N-2 -hydroxy-hexadecanoyl-1-Ο-$\beta$-D-glucopyranosyl-4-hydroxy-8-sphingenine (5) on the basis of spectroscopic methods.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.687-694
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• 1995

Alkalophilic Bacillus sp. HJ-12 producing $\beta $-1, 4-D-arabinogalactanase was isolated from soil in the alkalic condition, pH 10.0. $\beta $-1, 4-D-arabinogalactanase was maximaly produced in the medium consisting of 2% soybean arabinogalactan (SAG), 0.5% yeast extract, 0.5% polypeptone, 0.5% NaCl, 0.1% K$_{2}$HPO$_{4}$, 0.02% MgSO$_{4}$$\cdot $7H$_{2}$O, 0.1% Na$_{2}$CO$_{3}$ under the aerobic condition (pH 8.2). $\beta $-1, 4-D-arabinogalactanase is inducible enzyme so that its activity has been increased 10 fold in the SAG medium than in the glucose medium. Through the ammonium sulfate precipitation, DEAE- Sephadex A-50 ion chromatography, and Sephadex G-75 gel chromatography procedures, this enzyme was purified with a single protein of 11% vield and 110 fold's purity. $\beta $-1, 4-D-arabinogalactanase is endo type enzyme producing ollgosaccharide from SAG.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.293-299
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• 2003

Structure-activity relationship studies of allylamine type of antimycotics were carried out to evaluate the effect of naphthyl and methyl portion of naftifine. Compounds with 4-fluorophenyl(2a-5a), 2-fluorophenyl(2b-5b), 2,4-dichlorophenyl(2c-5c), 2,6-dichlorophenyl(2d-5d), 4-nitrophenyl(2e-5e), and 2,3-dihydro-benzo[1,4]dioxan-6-yl( 2f-5f) instead of naphthyl group with hydrogen(3a-3f), methyl(4a-4f), and ethyl(5a-5f) in the place of methyl in naftifine were synthesized and tested their in vitro anti-fungal activity against five different fungi. Eight compounds(3a, 5a, 3c, 4c, 4d, 5d, 5e, and 4f) showed significant antifungal activity against T. mentagrophytes. (E)-N-Ethyl-(3-phenyl-2-propenyl)-4-nitro-benzenemethaneamine(5e) displayed moderate antifungal activity against all five different fungi.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.265-272
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• 2003

This experiment was conducted to investigate the changes in meat quality characteristics on refri- gerated(4$^{\circ}C$) pork loin fed with supplemental levels of Bamboo vinegar(BV). Thirty pigs were divided into 3 groups of 10 pigs. Dietary levels of Bamboo vinegar 0%(control), 2% and 4% were included in experimental diets of each of the groups. The pH value was decreased(P<0.05) in 2% and 4% BV compared to the control after 3d of storage. Lightness was increased(P<0.05) in 2% and 4% BV compared to the control at 1d and 3d. Redness was decreased(P<0.05) in 4% VB compared to the control at 1d and 3d. The 2% and 4% BV showed a significant(P<0.05) increase in yellowness throughout the whole experiment compared to control. Cooking loss was increased(P<0.05) in 2% and 4% BV compared to the control after 3d of storage. Shear force was decreased(P<0.05) in 2% and 4% BV compared to control at 1d and 3d. TBA was decreased(P<0.05) in 2% and 4% BV at 6d and 9d. Total microbial counts was decreased(P<0.05) in 2% and 4% BV compared to control. The 2% and 4% BV scored higher(P<0.05) in odor evaluation compared to the control at 1d and 3d. The 2% and 4% BV also scored higher(P<0.05) than the control in the evaluation of appearance at 1d. The taste was increased(P<0.05) in 2% and 4% BV compared to control at 1d, 3d, and 6d. These results showed that the addition of 2% or 4% BV improved the meat quality and storage characteristics of refrigerated pork.

• Journal of Korea Multimedia Society
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• v.5 no.2
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• pp.222-230
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• 2002

Various virtual reality methods are examined on the internet. In this paper, 3D implementations on the internet are discussed using Java3D and GL4Java which are based on the Java. 3D shoppingmall, real time 3D renderings, and various objects are implemented using Java3D and GL4Java, respectively. Especially with Java3D, the file formats of VRML97, OBJ, and 3DS are implemented using Java3D loader, which shows that object implementation in Java3D is better than other methods. Also, the comparisons between Java3D and GL4Java are discussed.