• Title/Summary/Keyword: K-GIC

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The comparison of harmonic detection methods on the Power line (상용(220V/60Hz)전원의 고조파 검출 방식의 비교)

  • Jung Dong-Youl;Hwang Hwan-Young;Park Chong-Yeun
    • Proceedings of the KIPE Conference
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    • 2004.07b
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    • pp.883-886
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    • 2004
  • The current harmonic detector consists of the load current detector and the notch filter. It obtains the harmonic current from the output of the load current detector using the Notch filter. The GIC in the notch filter is used instead of inductor to minimize the magnitude and phase characteristics variation caused by using twin-T notch filter and passive elements(inductor).

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COMPARISON OF SHEAR BOND STRENGTH AND MARGINAL LEAKAGE OF RESIN MODIFIED GLASS IONOMER CEMENTS (강화형 글라스 아이오노머 합착용 시멘트의 접합강도 및 변연누출에 대한 연구)

  • Park, Hye-Yang;Oh, Nam-Sik;Lee, Keun-Woo;Lee, Ho-Yong
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.4
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    • pp.647-661
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    • 1997
  • The resin modified glass ionomer cements(RMGICs) have been used for years since 1989. Recently it has been developed for luting of fixed restorations. To evaluate the bond strength and marginal leakage of RMGICs for luting usage, the 80 extracted human molars which had uniform area of exposed dentin were cemented with 3 types of RMGICs(Fuji Duet, Advance, Vitremer), a conventional Glass Ionomer Cement(GIC-Fuji I), and a resin cement (Panavia 21) to base metal alloy(Ni-Cr-Be). After thermocycling the specimens were immersed in basic fuschin dye for measuring marginal leakage. The shear bond strength was measured with Instron and the maximum dye penetration was measured to 0.1mm. The types of fractured patterns were determined with stereoscope(${\times}7.5$). The results are as follows. 1. The difference between 3 RMGICs and a conventional GIC in shear bond strength was not statistically significant. It seemed that RMGICs had lower shear bond strength than resin cement. (p<0.01) 2. The mean scores of marginal leakage had no significant difference between the resin cement and 3 RMGICs but it was much higher in conventional GIC than the RMGICs (p<0.05) 3. It was determined that the manufacturer and the methods of dentin pretreatment determined the pattern of fracture surfaces and the frequency of adhesive failure between teeth and 3 RMGICs standed as in following order - Vitremer, Advance, Fuji Duet. (p<0. 01) When the fracture pattern was analyzed, it could be said that the materials and the method of dentin pretreatment have much effect on bonding states. This means that the dentin bonding agents should be improved. But the limited products in this experiment can not evaluate the physical properties of the entire RMGICs. Therefore a further study which can evaluate various RMGICs should be in progress to develope better cements.

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Reaction Pattern of Bacillus cereus D-11 Chitosanase on Chitooligosaccharide Alcohols

  • Gao, Xing-Ai;Jung, Woo-Jin;Kuk, Ju-Hee;Park, Ro-Dong
    • Journal of Microbiology and Biotechnology
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    • v.19 no.4
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    • pp.358-361
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    • 2009
  • The purified endochitosanase(Mw 41 kDa) from bacterium Bacillus cereus D-11 hydrolyzed chitooligomers $(GlcN)_{5-7}$ into chitobiose, chitotriose, and chitotetraose as the final products. The minimal size of the oligosaccharides for enzymatic hydrolysis was a pentamer. To further investigate the cleavage pattern of this enzyme, chitooligosaccharide alcohols were prepared as substrates and the end products of hydrolysis were analyzed by TLC and HPLC. The chitosanase split $(GlcN)_4GlcNOH$ into $(GlcN)_3+(GlcN)_1GlcNOH$, and $(GlcN)_5GIcNOH$ into $(GlcN)_4+(GlcN)_1GlcNOH$ and $(GlcN)_3+(GlcN)_2GlcNOH$. The heptamer $(GlcN)_6GlcNOH$ was split into $(GlcN)_5$ [thereafter hydrolyzed again into $(GlcN_3+(GlcN)2]+(GlcN)_1GlcNOH$, $(GlcN)_4+(GlcN)_2GlcNOH$, and $(GlcN)_3+(GlcN)_3GlcNOH$, whereas $(GlcN)_{1-3}GlcNOH$ was not hydrolyzed. The monomers GlcN and GIcNOH were never detected from the enzyme reaction. These results suggest that D-11 chitosanase recognizes three glucosamine residues in the minus position and simultaneously two residues in the plus position from the cleavage point.

Electrorefining Characteristics of Uranium by Using a Graphite Cathode (흑연 전극을 이용한 우라늄 전해정련 특성)

  • Kang, Young-Ho;Lee, Jong-Hyeon;Hwang, Sung-Chan;Shim, Joon-Bo;Kim, Eung-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.1
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    • pp.1-7
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    • 2007
  • Electrorefining experiments were successfully carried out in LiCl-KCl eutectic molten salt with a graphite cathode. It was found that the formation of Uranium-Graphite intercalation compound(U-GIC) helped the self-scraping mechanism of the uranium dendrite and the efficiency of the electrorefiner increased due to an elimination of the stripping step. The contaminations of the uranium deposit by rare earth elements was negligible while about 300 ppm of carbon was observed. The carbon contamination is believed to be eliminated by further purification by yttrium reaction. The morphology characteristics of the recovered U deposit was compared to that of steel cathode. These are only qualitative preliminary experimental results, but we believe that further research on this type of activity change the direction of the electrorefining research on spent nuclear fuel.

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THE INFLUENCE OF DENTIN DESENSITIZER TO SHEAR BOND STRENGTH OF DENIAL CEMENTS (상아질 지각완화제가 치과용 시멘트의 결합강도에 미치는 영향)

  • Na, Yun-Ho;Oh, Nam-Sik;Yoo, Jae-Heung
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.5
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    • pp.579-588
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    • 2007
  • Statement of problem: A tenderness of the dentin after tapering of teeth for dental prosthesis is a common phenomenon. In practice, the alternative desensitizer may be used for minor pain after tapering of teeth. Purpose: In this study, the desensitizers were used to investigate the affect decreasing of shear bond strength according to the use of various cement, such as resin, Glass Ionomer, and phosphate cement. Material and method: Three different desensitizers were used on this study Compositions of two dentin desensitizers were HEMA(hydroxyethylmethacrylate) and glutaraldehyde. The other one is oxalic acid. Three dentin desensitizers applied on 12 degrees taper teeth. Then, Ni-Cr crowns were bonded with Resin cement, Zinc Phosphate (ZPC) cement and Glass Ionomer (GIC) cement. 120 human premolar teeth were used for specimens. The specimens were divided into four group as the reference and the empirical each with thirty specimens, then further divided into 12 group according to type of desensitizers and cement types. The shear bond strength were measured by Instron multi task instrument. Results: According to the result, the measured shear bond strength in order from the weakest to the strongest in general was ZPC, Resin, and GIC. And it is found that the application of desensitizers on dentin surface does not affect the shear bond strength. Conclusion: Dentin desensitizers that alleviate or prevent a dentin tenderness, usually contains HEMA and glutaraldehyde compounds. Such desensitizers are widely used in clinical studies. By applying the dentin desensitizer on the exposed dentin surface, the dentin capillary are blocked and periodontal membrane and cementum can not be drawn in pulp cavity. Since HEMA and glutaraldehyde may cause harm to the pulp cavity, an alternative desensitizer was developed.

Jeju Jong-Nang Channel Code III (제주 정낭(錠木) 채널 Code III)

  • Park, Ju-Yong;Kim, Jeong-Su;Lee, Moon-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.5
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    • pp.91-103
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    • 2015
  • This paper presents "The 3-User NOR switching channel based on interference decoding with receiver cooperation" in succession to "Jeju Jong Nang channel code I, II". The Jeju Jong Nang code is considered as one of the earliest human binary coded communication (HBCC) in the world with a definite "1" or "0" binary symbolic analysis of switching circuits. In this paper, we introduce a practical example of interference decoding with receiver cooperation based on the three user Jong Nang NOR switching channel. The proposed system models are the three user Jong Nang (TUJN) NOR logic switching on-off, three-user injective deterministic NOR switching channel and Gaussian interference channel (GIC) with receiver cooperation. Therefore, this model is well matched to Shannon binary symmetric and erasure channel capacity. We show the applications of three-user Gaussian interference decoding to obtain deterministic channels which means each receiver cooperation helps to adjacent others in order to increase degree of freedom. Thus, the optimal sum rate of interference mitigation through adjacent receiver cooperation achieves 7 bits.

A COMPARATIVE STUDY OF WATER ABSORPTION AND RELATED CHANGES OF COMPRESSIVE STRENGTH IN THREE RESTORATIVE MATERIALS (치과용 수복재의 수분흡수도와 압축강도의 변화에 관한 연구)

  • Chang, Woo-Hyuck;Choi, Yeong-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.1
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    • pp.161-170
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    • 2003
  • The aesthetic restorative materials are widely used in recent dentistry, showed not only the different quality between each component but also showed that the environment of the material has important effect on the physical properties of the material. Especially, when the restoratives are restored in the mouth, and since saliva is existing, the restoratives are always exposed to water and affected by the saliva. The purpose of this study was to research and compare the change of the degree of water sorption after water immersion of three types of the resin-based materials and the compressive strength, and observe the relation between the change of the water absorbing degree and the compressive strength. Z-100(3M, U.S.A) as a composite resin, F-2000(3M, U.S.A) as a compomer and Vitremer Restoratives(3M, U.S.A) as a resin-modified GIC were used, and each specimen was made to measure the water sorption and to evaluate the compressive strength. The specimens for measurement of the water sorption and the compressive strength were divided into 4 groups(1 day, 2 weeks, 4 weeks, and 8weeks). Each specimen was filled in the 30cc vial with 20cc of distilled water during the fixed amount of period in $37^{\circ}C$. The water sorption is decided by dividing the difference of weight before and after the immersion by the volume, and the compressive strength was measured by using the instron after the immersion. The following results were obtained ; 1. The more the water sorption increased, the more the immersion period of three restorative materials was long. And the most of water sorption was obtained during the first 2 weeks(P<0.001). 2. The water sorption of resin-modified GIC was higher than composite resin and compomer. 3. The more the compressive strength decreased, the more the immersion period of three restorative materials increased(composite resin and compomer: P<0.001, resin-modified GIC: P<0.05). Especially, the amount of the reduction in compressive strength of the composite resin was the highest. 4. The more the water sorption of all materials increased, the more the compressive strength decreased(P<0.05).

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Realization of Hybrid Filter for Harmonics Elimination on the Power line (전원의 고조파 제거를 위한 Hybrid Filter의 실현)

  • Bang Sun-Bae;Jung Dong-Youl;Hwang Hwan-Young;Park Chong-Yeun
    • Proceedings of the KIPE Conference
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    • 2004.07b
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    • pp.764-768
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    • 2004
  • This paper proposed Hybrid Filter for harmonics elimilation on the power line. It's control method is very simple, but its performance is better than the results by passive filter. For the harmonics elimination, we improved the performance of the BPF(Band-pass Filter) with the GIC(Generalize Impedance Converter), and the new hysterisys controller.

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The harmonics detection system adapting the variation of source frequency (전원 주파수 변동에 적응하는 고조파 검출 시스템)

  • Hwang, Hwan-Young;Choi, Won-Ho;No, Kyung-Ho;Park, Chong-Yeun
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.195-197
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    • 2005
  • This paper proposed the new harmonic detection system for the source current with the large frequency variation. The harmonic detection system is designed of the analog circuit and is composed of a low pass filter, a DC-level converter using the PLL, the Voltage controlled GIC.

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A Study on Diagnostic model about global innovation capability of SMEs

  • Choi, Yun Jeong;Roh, Hyun Sook;Lim, Dae-Hyun
    • Proceedings of the Korea Contents Association Conference
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    • 2014.06a
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    • pp.191-192
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    • 2014
  • In this study, diagnostic model was proposed to evaluate and rate the innovation capability of SMEs and suggest alternatives to insufficient capabilities and optimum supporting programs for SMEs from literature survey, GIC model was composed based on KIS value and ASTI(Associate of Science and Technology information) SMEs database, thus, sample deviation can be caused and securing accurate data is insufficient. To compose model by analyzing characteristics of companies accurately, various companies' data for long period will be required.

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