• Korean Journal of Materials Research
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• v.6 no.5
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• pp.515-523
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• 1996

세라믹 전구체로서 PCS와 PMS 두 종류의 실린콘 고분자를 합성하여 7, 15, 33 wt.%의 Mo분말, Mo(CO)6 금속화합물과 혼합한 뒤 130$0^{\circ}C$이상 가열하면 탄화물과 규화물의 다양한 세라믹복합재로 전이되었다. 특히 PMS용액에 7, 15 wt.% Mo분말을 분산하여 초음파 처리하면 열분해 수율이 60%까지 개선되고 전도성 소재인 SiC/MoSi2 복합조성의 세라믹스가 합성되었다. 그러나 풍부한 유기 반응기를 가진 PCS와 카보닐기가 탄소공급원으로 작용하는 Mo(CO)6를 반응물로 사용하였을 때는 SiC와 Mo2C와 같은 탄화물과 미향의 MoSi2 그리고 미확인상을 포함한 세라믹 복합상들이 얻어졌다.

• Journal of the Korean Vacuum Society
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• v.8 no.4B
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• pp.497-506
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• 1999

Carbon has been widely used for the material of plasma facing components in fusion experiment devices like a tokamak, because carbon has good thermal and mechanical properties. However carbon gas a relatively high ougassing rate. Therefore the amount and the surface area of the carbon material used in the vessel will determine the background pressure of the vacuum vessel. In this experiment influences of carbon on the vacuum performance was investigated by measuring chamber pressure, ougassing rater and gas spectrum of carbon fiber composite (CFC) samples in various situations, pumping out, chamber baking, carbon heating (250~$500^{\circ}C$), exposure to atmosphere for maintenance of in-vessel components, etc., occurring routinely during tokamak operations.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.277-278
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• 2005

미생물 고정화를 위하여 PU 폼을 세 가지 처리 방법으로 처리하였다. 플라즈마 처리, 플라즈마 유도 그라프팅, 플라즈마 유도 그라프팅 후 플라즈마로 재처리 방법을 사용하였다. 플라즈마 처리는 bacteria adhesion에 큰 효과를 주지 못하였고, 아크릴산의 플라즈마 유도 그라프팅은 adhesion을 세 배 이상 증가시켰다. Bacteria의 adhesion 성능 향상은 표면의 친수성을 증가시키고 새로운 groove나 cavity들을 형성시킴으로 가능하였다. 반면, 그라프팅 후 plasma re-treatment는 미생물 고정화를 크게 향상시키지 못하였다. SEM 관찰을 통하여 대부분의 E.coli.는 groove나 cavities라는 shear-free area에 서식함을 알 수 있었다. PU폼의 bacteria adhesion은 미생물과 고분자 표면 사이의 정전기적 인력이나 van der Waals 인 력에 의해 주로 영향을 받는다고 사료된다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.29-34
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• 2007

월드와이드웹에서의 정보를 재사용, 공유할 수 있도록 기준을 제시한 XML은 많은 곳에서 사용 중에 있으며, 널리 확산되고 있다. 사용자 정의태그를 이용한 XML의 특징은, 같은 도메인의 문서라도 사랑의 인식이 아닌 컴퓨터와 같은 기계적으로는 다르게 인식될 수 있다는 문제점을 드러내기도 한다. 본 논문에서는 이러한 문제점을 해결하고자 시소러스와 온톨로지 등을 이용해 XML 문서간 유사도를 측정하는 방법을 제시하며 이를 바탕으로 제작한 프로그램인 #XML Similarity Calculation# 를 이용하여 제시한 방법이 타당하다는 것을 증명하게 된다. 또한 주어진 예시자료를 가지고 이 프로그램의 성능평가를 통해 정확성과 효율성을 평가하고 앞으로의 연구방향을 제시한다.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.06a
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• pp.149-154
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• 2003

경제성장과 더불어 발생되는 환경오염물질 배출의 증가로 인해 이를 규제하려는 세계적인 동향이 강화되어 이러한 환경문제를 경제 내적인 문제로 발전하고 있다. 특히 전력부문에 있어서 여러 가지 투자대안들이 환경에 미치는 영향을 고려할 경우, 각 대안들이 전력을 생산하기 위해 필요한 비용은 사회적 비용을 고려치 않는 사적인 비용과 커다란 차이가 생길 수 있다. 이에 본 연구에서는 균등화발전 원가법으로 유연탄과 LNG화력 발전의 경제성을 분석하였는데. 환경 규제상황에서 발전원간 평가를 위해 저감설비 도입비용, 탄소세, 연료비 인상, 할인율 변동에 따른 경제성 비교를 통하여 유연탄 및 LNG발전의 발전원가를 컴퓨터 시뮬레이션에 의한 민감도 분석을 통해 비교하였다.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.45-58
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• 2013

The purpose of this study was to analyze the area of occlusal contact points using visual method. One subject was selected who had Angle Class I, normal dentition, without dental caries, periodontal disease and temporomandibular disorders. Forty times PVS impressions were taken and 10 pairs casts were fabricated using dental super hard stone. After mounting the casts with customized loading apparatus, 78.9kg/f force was loaded as a maximum biting force. In T-Scan method, occlusal contact points measurement was repeated twice. Then, using Photoshop program (Adobe photoshop CS3, Adobe. San Jose, USA), the pixels which indicated occlusal contact points by color was recognized, and the distribution of recognized pixels were calculated to area. In Add picture method, polyether bite material applied to the occlusal surface of the casts. Then, the image of the translucent areas was recorded and classified $0{\sim}10{\mu}m$, $0{\sim}30{\mu}m$, $0{\sim}60{\mu}m$ area by the amount of transmitted light. To acquire occlusal surface, the numbers of pixels from the photograph of the contact area indicated cast converted to $mm^2$. The mean occlusal contact area by two methods was statistically analyzed (paired t-test). Part of the red and pink area in T-Scan image were almost equivalent to the $0{\sim}10{\mu}m$, $0{\sim}30{\mu}m$, $0{\sim}60{\mu}m$ area in Add picture image. The distribution of occlusal contact points were similar, but the average area of occlusal contact points was wider in T-scan image (P<.05). Pink and red area in T-scan image was wider than $0{\sim}10{\mu}m$, $0{\sim}30{\mu}m$ area in Add picture image (P<.05), but similar to $0{\sim}60{\mu}m$area in Add picture image (P>.05). Occlusal contact points in T-scan image did not indicate real occlusal contact points. Occlusal contact areas in T-scan method were enlarged results comparing with those in Add picture method.

• Journal of Korean society of Dental Hygiene
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• v.8 no.2
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• pp.53-66
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• 2008

There was to purpose of this study improves analyzing cause that prosthesis brings bite engaging that is inaccurate in patient's mouth, when supposed that all conducts that do in operatory and dental laboratory are perfect. Impression did check bite by alginate impression material and polymerization style silicon impression material that use usually in presence at a sickbed Irreversibility, hydrocolloid, alginate impression material washed in flowing water and poured anhydrite after wait about 8 minutes so that region that charge interest after impression check bite may become undoing. And hydrophile property addition polymerization style impression material poured anhydrite after blow 30 considering impression material dwell time and H2 gas occurrence time (5~15 minute) after have washed in flowing water. I got each 7 models, result that manufactures total 28 and measures by third dimension measuring instrument (Meteo, Korea) following sequence curing in tray holder and floor 1, By Alginate impression when is hardened in tray holder and when is hardened in the floor after do check bite, SPH 4, SPH5 all as there is synonymy appeared(P<0.05). By in case do not use average 0.1741 in case use tray holder in 0.0447 SPH5s in case do not use average 0.2838 pastas in case use tray holder in SPH4 0.0309, When did not use both SPH4 and SPH5 tray holder, when used tray holder, 1 appeared more greatly. 2. By amity sex addition polymerization style silicon impression when is hardened in tray holder after do check bite and when is hardened in the floor SPH 4, a11 of the SPH5s very big synonymy be(P>0.05). And in case use tray holder in 0.000657 pasta SPH5s in case do not use average 0.000129 pastas in case use tray holder in SPH4 average 0.000114 pastas, by in case do not use 0.000757, I appeared more greatly when used tray when did not use both SPH4 and SPH5 tray holder, but 1 appeared is not level to keep in mind(Table 8~9). 3 SPH4 was looked very big mindfulness in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon without using tray holder(P< 0.001). I use tray holder and SPH4 did not appear synonymy in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon(P>0.05). Study finding of above when see synthesis Alginate certainly tray holder use must and I could know that hardening method does not exert big influence on volume stability if remove impression sieve of excess because amity sex accessory penalty silicon passes over tray, Also, Alginate impression material previewed can get heading a conspiracy style that volume stability of accessory penalty silicon impression material degree is if use tray holder.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.2
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• pp.266-276
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• 1996

Numerous factors are known to affect the accuracy of elastomeric impression materials. Factor often overlooked is the quality of the bond between putty and wash during corrective reline impression technique. The putty-wash bond strength must be strong enough to over-come the local stress at putty-wash interface. It is not always possible to avoid saliva contamination in making corrective wash impres-sion. And putty preliminary impression material con be used as a template for provisional restoration. Human saliva and the residual monomer of autopolymerizing acrylic resin are thought to affect the bond strength and the failure type. This study examined the effect of contaminants like human saliva, and residual resin monomer on the putty-wash bond strength and the effectiveness of treatment. 1. Of the tested three brands of Vinyl Polysiloxane impession meterial, Express Exhibited the greatest bond strength followed by Eamix and Perfect showed the lowest putty-wah bond strength. 2. Coating the putty substrates with human saliva did not produce decreased failure load in all the breands of Vinyl Polysiloxane impression meterail. 3. Of the three brands of VPS impression material that were exposed to methhylmethacry-late resin(Jet), only the putty-wash bond strength of the Perfect group diminished signifi-cantly. Moreover, all the specimens from group C of Perfect exhibited adhesive failure. 4. Exposing the substrates to ethylmethacrylate resin(SNAP. diminished the putty-wash bond strength significantly. With Perfect and Examix, failure occurred cohesively through the light-body, whereas with Express, failure occurred adhesive-cohesively. 5. Removing approximately 1mm thickness of the contaminated putty interface was the most effective treatment in countering the undesirable effect caused by residual resin monomer. The putty-wash bond strength of the groups that were treated with 1mm even putty reduction was not significantly different from those of control groups. With Perfect and Examix, cleaning the specimens with gauze soaked in 70% isopropyl alcohol increased the putty-wash bond strength, but was not as effective as 1mm even reduction of contaminated putty substrates. With Express, 70% isoproryl alcohol treatment exhibi0ted comparable putty-wash bond strength to that of control group.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.5
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• pp.230-234
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• 2013

IR cut-off thin films consisted of ATO nanoparticles were successfully fabricated by sol-gel method. The coating solution was synthesized with organic/inorganic hybrid binder and ATO colloidal solution and ATO thin films were coated on a slide glass with the withdrawal speed of 5~40 mm/s. As the withdrawal speed increased from 5 mm/s to 40 mm/s, the thickness of coating thin films also increased from $1.05{\mu}m$ to $4.25{\mu}m$ and the IR cut-off in wavelength of 780~2500 nm increased from 49.5 % to 66.7 %. In addition, the pencil hardness of ATO thin films dried at $80^{\circ}C$ was ca. 5H and the coating films were not removed after a cross cutter tape test because of the hybrid binder synthesized with tetraethylorthosilicate and methyltrimethoxysilane. The surface morphologies, optical properties and film thickness of prepared thin films with a different withdrawal speed were measured by field emission scanning electron microscope (FE-SEM), UV-Vis spectrophotometer, and Dektak.

• Elastomers and Composites
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• v.44 no.2
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• pp.150-155
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• 2009

This study examined the effects of the concentration variation of the silyl hydride (Si-H) functional group in polymethylhydrogen siloxane cross-linker and the vinyl-functional group in silicone prepolymer on the physical properties of the dental polyvinylsiloxane impression materials (PVS). When the SiH/Vinyl ratio was 1.6 (Group $\underline{C6}$ containing ${\underline{C}}ross$-linker $\underline{6}$ parts), the setting rate was too slow even though their tensile strength was the highest within the tested groups. When the SiH/Vinyl ratio was 3.2 (Group C12), the setting rate was too fast to allow appropriate working time even though their mechanical properties were good. The C14 group showed rather lower tensile strength compared to the groups having lower cross-linker contents. Notably, too much incorporation of cross-linker, like C16 group, induced delay of the setting, by which the mechanical and manipulation properties were detrimentally affected.