• 제목/요약/키워드: DTA

검색결과 958건 처리시간 0.027초

함정 전·평시 OMS/MP 설정 방법론 연구 및 사례 (A Wartime·Peacetime OMS/MP Analysis Model for a Naval Ship and Case Study)

  • 하성철;국정호
    • 한국군사과학기술학회지
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    • 제15권5호
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    • pp.660-666
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    • 2012
  • The weapon system is getting more and more expensive, complex and smarter. Therefore, efficiently and effectively, it is important to operate the weapon system. OMS/MP is a document to quantify operational factors like as environment, mission, mode etc. It is important data to perform RAM analysis in early weapon development phase and operate better a weapon system. This paper present a process and framework of OMS/MP for a naval ship with a deep analysis of relevant domestic and abroad case studies. It propose OMS/MP analysis framework based on wartime scenario and mission area analysis. This result will contribute not only improvement for the availability of a naval ship but also enhancement of RAM analysis process.

진공증착법에 의한 P(VDF-TrFE) 공중합체 박막의 제조 (Fabrication of P(VDF-TrFE) copolymers thin films by physical vapor deposition method)

  • 윤종현;정무영;이선우;박수홍;이상희;임응춘;유도현;이덕출
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.367-370
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    • 2000
  • In this study, thin films of 70/30 and 80/20 mol% P(VDF-TrFE) copolymers were fabricated by physical vapor deposition method. In order to determine the optimum deposition condition, the copolymer thin films were fabricated in the heating temperature of 260$^{\circ}C$, 280$^{\circ}C$, and 300$^{\circ}C$. The deposition rate was measured in a real time by thickness monitor. The surface image of prepared thin films was analyzed by using AFM. From the results of TG-DTA,70/30 and 80/20 mol% P(VDF-TrFE) copolymers were observed the Curie transition point below the melting point. As the results of AFM and FT-IR analysis, we determined that the optimum deposition temperature was 300$^{\circ}C$.

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PDP 유전체용 BaO-ZnO-$B_2O_3-V_2O_5$ 유리의 제조 및 특성 변화 (Preparation and properties of BaO-ZnO-$B_2O_3-V_2O_5$ glass for PDP dielectric paste)

  • 손명모;이상근;박희찬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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    • pp.295-298
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    • 2003
  • The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system BaO-ZnO-$B_2O_3-V_2O_5$. DTA, XRD and SEM were used to study and characterize BaO-ZnO-$B_2O_3-V_2O_5$ glasses. PbO free paste developed at this paper has thermal expansion of $74{\times}10^{-7}/^{\circ}C$, DTA transformation point of $460^{\circ}C$, and firing condition of $560^{\circ}C$, 10min.

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PZT 이종층 후막의 구조적, 전기적 특성 (Structural and Electrical Properties of PZT Heterolayered Thick Films)

  • 이성갑;임성수;이영희;이종덕;박상만
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.1915-1917
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    • 2005
  • PZT(40/60) and PZT(60/40) powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PZT(40/60)/PZT(60/40) heterolayered thick films were fabricated by the screen-printing method on $Pt/Al_2O_3$ substrates. The structural properties such as DTA, X-ray diffraction and microstructure, were examined as a function of the applied pressure. In the DTA analysis, the formation of the polycrystalline perovskite phase was observed at around $880^{\circ}C$. The average thickness of the PZT heterolayered thick films which were coated five times was approximately $95-100{\mu}m$.

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PZT(20/80)/PZT(80/20) 이종층 후막의 유전특성 (Dielectric Properties of PZT(20/80)/PZT(80/20) Heterolayered Thick Films)

  • 이성갑;이영희;배선기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.1918-1920
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    • 2005
  • PZT(20/80) and PZT(80/20) powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PZT(20/80)/PZT(80/20) heterolayered thick films were fabricated by the screen-printing method on $Pt/Al_2O_3$ substrates. The structural properties such as DTA, X-ray diffraction and microstructure, were examined as a function of the sintering temperature. In the DTA analysis, the formation of the polycrystalline perovskite phase was observed at around $880^{\circ}C$. The average thickness of the PZT heterolayered thick films was approximately $80-90{\mu}m.$

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PDP용 무연프리트 유리의 제조 및 특성 (Preparation and properties of PbO Free for PDP Rib Paste)

  • 손명모;이헌수;이창희;이상근;박희찬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.524-525
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    • 2005
  • The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system $ZnO-B_2O_3-Bi_2O_3-SiO_2$, DTA, and XRD were used to characterize $ZnO-B_2O_3-Bi_2O_3-SiO$ glasses. In this present study, PbO free paste had thermal expansion of $74\times10^{-7}/^{\circ}C$, DTA transformation point of $470^{\circ}C$, and firing condition of $540^{\circ}C$, 20min.

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소결조건에 따른 $Pb(Zr_xTi_{1-x})O_3$ 이종층 후막의 유전특성 (Dielectric Properties of $Pb(Zr_xTi_{1-x})O_3$ Heterolayered Thick Films with Variation of Sintering Conditions)

  • 이성갑;이종덕;박상만
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.359-360
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    • 2005
  • PZT(20/80) and PZT(80/20) powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PZT(20/80)/PZT(80/20) heterolayered thick films were fabricated by the screen-printing method on Pt/$Al_2O_3$ substrates. The structural properties such as DTA, X-ray diffraction and microstructure, were examined as a amount of the excess PbO. In the DTA analysis, the formation of the polycrystalline perovskite phase was observed at around $880^{\circ}C$. The average thickness of the PZT heterolayered thick films was approximately $80{\mu}m$.

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Chemical Composition and Thermal Changes of Natural Pyrrhotite

  • Moon-Young Kim;Hong-Ja Shin
    • 한국광물학회지
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    • 제3권2호
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    • pp.65-71
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    • 1990
  • Compositions and thermal changes of pyrrhotites from Ohtani and Uljin mines were examined by Arnold's method and DTA analysis. The results are as follow: 1) The compositions of hexagonal type pyrrhotite are in some range from 47.23-47.42 atom.% Fe in the Ohtani mine, and 47.40-47.64 atom.% Fe in the Uljin mine. 2) The compositions of hexagonal pyrrhotite with exsoluted lamellae of monoclinic pyrrhotite are in 47.35-47.50 atom.% Fe in the Ohtani mine, and 47.15-47.40 atom.% Fe in the Uljin mine. This fact does not agree with phase diagrams of Fe-S system shown by Nakazawa and Morimoto(1970) and Sugaki and Shima(1977). 3) DTA data show two endothermic peak corresponding to ${\gamma}$ and $\beta$ transformation. Sturctural conversions from order(intermediate) to disorder(high) forms occur at about $300^{\circ}C$ for hexagonal type and further lower temperature with increasing Fe-content.

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분산데이터베이스 환경하의 시간연관규칙 적용 (Discovery Temporal Association Rules in Distributed Database)

  • Yan Zhao;Kim, Long;Sungbo Seo;Ryu, Keun-Ho
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2004년도 봄 학술발표논문집 Vol.31 No.1 (B)
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    • pp.115-117
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    • 2004
  • Recently, mining far association rules in distributed database environments is a central problem in knowledge discovery area. While the data are located in different share-nothing machines, and each data site grows by time. Mining global frequent itemsets is hard and not efficient in large number of distributed sewen. In many distributed databases. time component(which is usually attached to transactions in database), contains meaningful time-related rules. In this paper, we design a new DTA(distributed temporal association) algorithm that combines temporal concepts inside distributed association rules. The algorithm confirms the time interval for applying association rules in distributed databases. The experiment results show that DTA can generate interesting correlation frequent itemsets related with time periods.

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PREPARATION OF CERIUM DOPED TITANIA NANO POWDER FOR PHOTOCATALYST

  • Musyoki, Euphracia Ndinda;Kim, Kyung-Nam
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2012년도 춘계학술발표회 논문집
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    • pp.257-257
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    • 2012
  • Cerium doped anatase titania powders were prepared by sol-gel process, with ammonium (IV) nitrate and Titanium (IV) butoxide as the raw materials. The characteristics of anatase $TiO_2$ and cerium doped $TiO_2$ were investigated by XRD, DTA, FE-SEM and UV/Vis spectroscopy. Research results indicated that XRD data characteristic diffraction peaks of anatase phase and also showed that cerium phase was not observed. Moreover XRD and DTA results imply that the addition of cerium to titania modifies the mechanism of formation of the titania phases.

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