• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2223-2226
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• 2009

Pristine and sulfur-doped (LiFe$PO_{3.98}S_{0.03}$) lithium iron phosphates were synthesized by a sol-gel method. The XRD pattern of the prepared materials suggested an orthorhombic structure with a Pnma space group and an absence of impurities. The Li/LiFe$PO_4$ or LiFe$PO_{3.98}S_{0.03}$ cells were employed for cycling studies at various temperatures (25, 50 and $60\;{^{\circ}C}$). In all cases, the Li/LiFe$PO_{3.98}S_{0.03}$ cell showed an improved performance with a stable discharge behavior of ~155 mA$hg^{-1}$. Nevertheless, pristine LiFeP$O_4$ cells presented poor discharge behavior at elevated temperatures, especially $60\;{^{\circ}C}$.

• Restorative Dentistry and Endodontics
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• 제42권1호
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• pp.39-47
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• 2017

Objectives: Although the coating of surface sealants to dental composite resin may potentially reduce bacterial adhesion, there seems to be little information regarding this issue. This preliminary in vitro study investigated the adhesion of Streptococcus mutans (S. mutans) on the dental composite resins coated with three commercial surface sealants. Materials and Methods: Composite resin (Filtek Z250) discs (8 mm in diameter, 1 mm in thickness) were fabricated in a mold covered with a Mylar strip (control). In group PoGo, the surfaces were polished with PoGo. In groups PS, OG, and FP, the surfaces polished with PoGo were coated with the corresponding surface sealants (PermaSeal, PS; OptiGuard, OG; Fortify Plus, FP). The surfaces of the materials and S. mutans cells were characterized by various methods. S. mutans adhesion to the surfaces was quantitatively evaluated using flow cytometry (n = 9). Results: Group OG achieved the lowest water contact angle among all groups tested (p < 0.001). The cell surface of S. mutans tested showed hydrophobic characteristics. Group PoGo exhibited the greatest bacterial adhesion among all groups tested (p < 0.001). The sealant-coated groups showed statistically similar (groups PS and FP, p > 0.05) or significantly lower (group OG, p < 0.001) bacterial adhesion when compared with the control group. Conclusions: The application of the surface sealants significantly reduced S. mutans adhesion to the composite resin polished with the PoGo.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1223-1225
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• 2001

This paper describes the simulation algorithms and user interfaces of the self-developed CaPoDyS which is to simulate the dynamic interaction between catenary and pantograph based on FEM. Also, the reliability of the simulation results are discussed through comparing with the ERRI report.

• 대한수학회논문집
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• 제13권1호
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• pp.1-6
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• 1998

The paper refers to ordered semigroups in which $x^2 (x \in S)$ are left ideal elements. We mainly show that this $po$-semigroup is left regular if and only if S is a union of left simple subsemigroups of S.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2004년도 춘계학술발표대회
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• pp.1217-1220
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• 2004

현재까지 IDS는 관리자의 개입 없이는 효과적인 운용이 불가능하고, IDS를 사용하더라도 여전히 침입 발생 가능성이 있고, 다양한 우회 가능성이 존재한다. 본 논문에서는 기존에 제안된 침입탐지 시스템을 분석하고, C-Box에 규정된 정책을 이용한 데이타소스 기반의 침입탐지 시스템을 설계하여 이를 실험하였다. 본 연구는 데이터 소스 기반에서 침입 탐지 방법 기준의 비정상적인 형태에 의한 탐지와 오류에 의한 탐지기법을 적용하였으며, IDS에 침입 탐지 정책을 설계하였고, 규정에 의한 정책중심의 침입탐지 기법을 정상적인 동작과 비정상적인 동작을 구분하는 경계를 정의한다. 또한, 침입탐지 정책을 이용한 호스트기반 IDS를 설계하고 구현함으로서 정보시스템의 취약성을 보완할 수 있었다. 침입탐지 실험을 위한 시스템 호출 기술은 커널에 프로세스들의 특성을 자세하게 정의하고, 이를 실행할 수 있도록 기반을 구축함으로서 가능하게 하였다.

• 센서학회지
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• 제27권1호
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• pp.36-39
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• 2018

Transparent olivine $LiNiPO_4$ thin films on sapphire substrates were fabricated by radio frequency (RF) magnetron sputtering. The X-ray diffraction patterns show these thin films have the phase of $LiNiPO_4$ with an ordered olivine structure indexed to the orthorhombic Pmna space group. $LiNiPO_4$ thin films deposited on sapphire substrates exhibit transmittance of about 83 %. It was confirmed that the $LiNiPO_4$ thin film exhibits a high potential of 5 V-class.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.659-660
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• 2006

The low crosstalk row-decoder is studied for PoRAM applications. Because polymer-based memories can be more densely integrated than established silicon-based ones, PoRAM is highly sensitive for the crosstalk problem. To overcome the problem and to suggest the suitable decoder for PoRAM, this paper shows the comparison of the row-path characteristics for both the 2-stage dynamic logic decoder and the 2-stage static logic decoder. Moreover, to suppress the Glitch effect which is observed by using the static logic decoder, the Master-Slave(M/S) D-Flip/Flop(D-F/F) is applied as a deglitch. Finally, the improved output result of the 2-stage static logic decoder with the M/S D-F/F is shown..

• Bulletin of the Korean Chemical Society
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• 제9권1호
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• pp.21-24
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• 1988

The electrical conductivitv of the system $ThO_2-Ho_2O_3$ was measured in the temperature range 600-$1100^{\circ}C$ and $Po_2$range $10^{-5}-2{\times}10^{-1}$ atm. The mean value of activation energy was 1.45 eV. The observed conductivity dependence on $Po_2$ was ${Po_2}^{1/4}$ at $Po_2$'s above $10^{-3}$ atm and was independent on oxygen partial pressure at $Po_2$'s below $10^{-3}$ atm. It is suggested that these dependences are due to a mixed ionic plus electron hole conduction by Vo defect.

• 한국재료학회지
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• 제30권11호
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• pp.601-608
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• 2020

In this work, Ag₃PO₄/In₂S₃ nanocomposites with low loading of In₂S₃ (5-15 wt %) are fabricated by two step chemical precipitation approach. The microstructure, composition and improved photoelectrochemical properties of the as-prepared composites are studied by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photocurrent density, EIS and amperometric i-t curve analysis. It is found that most of In₂S₃ nanoparticles are deposited on the surfaces of Ag₃PO₄. The as-prepared Ag₃PO₄/In₂S₃ composite (10 wt%) is selected and investigated by SEM and TEM, which exhibits special morphology consisting of lager size substrate (Ag₃PO₄), particles and some nanosheets (In₂S₃). The introduction of In₂S₃ is effective at improving the charge separation and transfer efficiency of Ag₃PO₄/In₂S₃, resulting in an enhancement of photoelectric behavior. The origin of the enhanced photoelectrochemical activity of the In₂S₃-modified Ag₃PO₄ may be due to the improved charge separation, photocurrent stability and oriented electrons transport pathways in environment and energy applications.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4878-4883
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• 2015

IMS(IP Multimedia Subsystem)는 전송 및 서비스들로부터 제어 기능들을 분리하도록 설계되었으며, 이러한 구조를 바탕으로 보장된 QoS(Quality of Service) 및 관리 기능을 수행하여 언제 어디서나 인터넷의 콘텐츠 및 텔레컴 서비스들을 접근할 수 있도록 제공하는 프레임워크 이다. SDP(Service Delivery Platform)는 기존 및 신규 서비스들을 효율적인 방법으로 전개하기 위하여 공통의 프로토콜 및 인터페이스를 제공한다. 따라서 IMS 상의 SDP는 응용 서비스들 사이의 상호작용을 단순화하여 수행할 수 있으며, 이러한 인터페이스를 통하여 기 구축된 네트워크와 신규 IMS 네트워크 사이에서 교량 역할을 수행한다. 멀티미디어 네트워크 통신을 풍부하도록 구축하기 위하여, 모바일 네트워크상에서 전개될 수 있는 후보 서비스들 가운데 대표적이며 독특한 반 이중 방식의 VoIP(Voice Over IP) 응용 서비스로 고려되는 PoC(Push-to-talk over Cellular) 서비스를 전개하려 한다. 본 논문에서는 PoC 서비스 및 구조의 장점을 조사하고, PoC 서비스 전개를 통한 실행을 통한 가능성 및 실현을 확인하기 위하여 프로토타입(prototype)을 구축하는 실질적 구현에 집중하였다.