• 제목/요약/키워드: Composition structural system

검색결과 176건 처리시간 0.039초

전기-유압식 추력벡터제어 구동장치시스템의 합성공진 특성 연구 (Research of Synthetic Resonance Characteristics for Electrohydraulic Thrust Vector Control Actuation System)

  • 민병주;최형돈;강이석
    • 항공우주기술
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    • 제7권1호
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    • pp.151-160
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    • 2008
  • 본 논문에서는 발사체에 적용하는 전기-유압식 추력벡터제어 구동장치시스템의 합성공진 현상에 대한 해석 연구결과를 기술한다. 합성공진 현상은 위치서보 구동장치시스템을 유연한 발사체 기체구조체 지지부에 장착하였을 때 발생한다. 이는 관성부하를 갖는 전기-유압식 위치서보 시스템의 유압공진 현상과 유연한 기체구조체 지지부의 구조공진 현상의 합성에 의하여 발생한다. 합성공진 현상은 발사체 제어시스템에 의하여 되먹임 및 증폭되어 안정성을 악화시킬 수 있다. 이와 같은 현상을 정확하게 예측 및 분석할 수 있는 비선형 모델을 개발하였으며 이에 기반을 둔 합성공진 억제 특성이 우수한 동적 압력 되먹임(dynamic pressure feedback) 제어기법을 개발하였다.

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PDP의 격벽 형성 공정인 감광성 공법에서 $B_2O_3-Al_2O_3-SiO_2$계 유리 조성의 열적 특성과 굴절률 변화 (Thermal Properties and Refractive Index of $B_2O_3-Al_2O_3-SiO_2$ Glasses for Photolithographic Process of Barrier Ribs in PDP)

  • 황성진;원주연;김형순
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.321-321
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    • 2008
  • To obtaingood resolution in PDP, one of the important factors is to achieve the accuracy of barrier ribs. The photolithographic process can be used to form patterns of barrier rib with high accuracy and a high aspect ratio. The composition for photolithography is based on the $B_2O_3-SiO_2-Al_2O_3$ glass system including additives such as alkali oxides and alkali earth oxides. The refractive index and thermal properties in glass system are changed by amount of alkali oxides and alkali earth oxides. Therefore, it is important that additives are controlled to have proper refractive index and thermal properties. The additives are contributed to non-bridging oxygen within the glass network, causing a change of density. In addition to a change of the structural cross-link density, the refractive index, dielectric and thermal properties glass are correlated with ionic radius and polarizability of cations. In this study, we investigated the refractive index and the thermal properties such as glass transition temperature, glass softening temperature and coefficient of thermal expansion by changing composition in the $B_2O_3-SiO_2-Al_2O_3$ glass system.

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신앙구조(信仰構造)를 통해 본 사찰공간(寺刹空間) 구성(構成)에 관한 연구(硏究) (A study on the Buddist Temple Space through the religious composition)

  • 김승제;김진덕
    • 한국농촌건축학회논문집
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    • 제4권3호
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    • pp.23-37
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    • 2002
  • Buddhist Architecture should be set for worship and an ascetic life, which is its main function as it is a religious facility and its space and form can be considered as means to achieve efficiently a religious function. Every religion concludes its religious function through its ideas and form of faith based on scriptures and religious precepts. The thing should be paid attention to from this point of view is how Buddhist doctrines are reflected on the architecture and the background recognition about the fundamental doctrines and religious system should be preceded to clarify it. Existing researches have studied the characteristics of Buddhist temples on the point of functional view and architectural spacial view through phenomenal ways. Though fruitful results bore about the Korean space through that way, more internal viewpoint is required to clarify the fundamental regularities and spatial concepts indwelling in temple architecture. Considering what structural elements were required to compose one space in traditional Korean architecture is the fundamental subject and important. This thesis searches architectural characteristics through inquiring about the main building and annexes and understanding symbolic characteristics about the arrangement of the Buddhist statue and solemn things in the Buddhist temples of tangible cultural assets or above located in Seoul area.

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Cu/In 비에 따른 $CuInS_{2}$ 박막의 특성에 관한 연구 (A Study on Properties of $CuInS_{2}$ thin films by Cu/In ratio)

  • 양현훈;김영준;정운조;박계춘
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.326-329
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    • 2007
  • $CuInS_{2}$ thin films were synthesized by sulpurization of Cu/In Stacked elemental layer deposited onto glass Substrates by vacuum furnace annealing at temperature 200[$^{\circ}C$]. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor $CuInS_{2}$ thin films with non-stoichiometry composition. $CuInS_{2}$ thin film was well made at the heat treatment 200[$^{\circ}C$] of SLG/Cu/ln/S stacked elemental layer which was prepared by thermal evaporator, and chemical composition of the thin film was analyzed nearly as the proportion of 1 : 1 : 2. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM and Hall measurement system. At the same time, carrier concentration, hall mobility and resistivity of the thin films was $9.10568{\times}10^{17}$ [$cm^{-3}$], 312.502 [$cm^{2}/V{\cdot}s$] and $2.36{\times}10^{-2}$ [${\Omega}{\cdot}cm$], respectively.

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${\gamma}$-$6Bi_2O_3$.$SiO_2$ 결정을 포함하는 복합다결정체의 작성 (Preparation of Composite Polycrystals Including ${\gamma}$-$6Bi_2O_3$.$SiO_2$)

  • 김호건
    • 한국세라믹학회지
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    • 제23권2호
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    • pp.13-20
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    • 1986
  • Composite polycrystals including ${\gamma}$-$6Bi_2O_3$.$SiO_2$ crystal which have needlelike regular structure are useful for the high resolution optical devices. For the purpose of obtaining the composite polycrystals described above the melts of eutectic composition in the three eutectic systems including $6Bi_2O_3$.$SiO_2$ composition were unidirectionally solidified at a rate of 0.05 and 0.25 cm/h under a thermal gradient of 10$0^{\circ}C$/m. Composite polycrystals of relatively regular structure in which needlelike ${\gamma}$-$6Bi_2O_3$.$SiO_2$ crystals were arrayed in parallel with $2Bi_2O_3$.$B_2O_3$ crystal matrix were obtained when the eutectic melt of $6Bi_2O_3$.$SiO_2 -2Bi_2O_3$.$B_2O_3$ system was solidified at a rate of 0.25 cm/h. Partial structural irregularity however was found in the obtained composite polycrystals.

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PRAM 용 GST계 상변화 박막의 조성에 따른 특성 (Properties of GST Thin Films for PRAM with Composition)

  • 장낙원
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권6호
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    • pp.707-712
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    • 2005
  • PRAM (Phase change random access memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change materials have been researched in the field of optical data storage media. Among the phase change materials. $Ge_2Sb_2Te_5$ is very well known for its high optical contrast in the state of amorphous and crystalline. However the characteristics required in solid state memory are quite different from optical ones. In this study. the structural Properties of GeSbTe thin films with composition were investigated for PRAM. The 100-nm thick $Ge_2Sb_2Te_5$ and $Sb_2Te_3$ films were deposited on $SiO_2/Si$ substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films. x-ray diffraction (XRD). atomic force microscopy (AFM), differential scanning calorimetry (DSC) and 4-point measurement analysis were performed. XRD and DSC analysis result of GST thin films indicated that the crystallization of $Se_2Sb_2Te_5$ films start at about $180^{\circ}C$ and $Sb_2Te_3$ films Start at about $125^{\circ}C$.

조성비에 따른 $CuInS_2$ 박막의 특성변화에 관한 연구 (A Study on Properties of $CuInS_2$ thin films by composition ratio)

  • 양현훈;김영준;정운조;소순열;이진;정해덕;박계춘;최용성;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.1268-1269
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    • 2008
  • $CuInS_2$ thin films were fabricated by sulpurization of Cu/In Stacked elemental layer deposited onto glass substrates by vacuum annealing at various temperatures. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor $CuInS_2$ thin films by composition ratio. Physical properties of the thin film were investigated at various fabrication conditions; substrate temperature, annealing temperature and annealing time by XRD, FE-SEM and hall measurement system. $CuInS_2$ thin film was well made at the heat treatment 200[$^{\circ}C$] of SLG/Cu/In/S stacked elemental layer.

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위상 변위기용 $BaTiO_3$계 세라믹의 유전특성 (Dielectric Properties of $BaTiO_3$ System Ceramics for Microwave Phased Shifter)

  • 이성갑;박상만;박인길;임성수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.79-82
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    • 2002
  • $(Ba_{0.6-x}Sr_{0.4}Ca_x)TiO_3$ + ywt% MgO (x=0.10, 0.15, 0.20, y=0.0~3.0) ceramics were fabricated by the conventional solid-state reaction, and their structural and dielectric properties were investigated with variation of composition ratio and MgO doping content. A second phase, representative of MgO, appears in 3wt% MgO-doped BSCT specimens. Average grain sizes decreased with increasing amounts of MgO, and the BSCT(40/40/20) specimens doped with 3wt% MgO showed a value of $9.3{\mu}m$. The Curie temperature and relative dielectric constant at room temperature were decreased with increasing MgO doping content and Ca composition ratio. The relative dielectric constant was non-linearly decreased as the field strength is increased. The tunability was increased with decreasing a Ca content and the BSCT(50/40/10) specimen doped with 1.0wt% MgO content showed the highest value of 6.4% at 5kV/cm.

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전통한옥 '칸'의 계획과 구성에 관한 연구 (A Study on Planning and Composition of Module Unit in Korean Traditional House)

  • 김종훈
    • 한국주거학회논문집
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    • 제23권4호
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    • pp.41-48
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    • 2012
  • The purpose of the study, approaching from the aspect of the construction technologies, is to determine the architectural techniques of traditional wood architects in existence, through which the systems and techniques that create the inherent characteristics of Korean Architecture are clarified. With understanding traditional construction system and focusing on the fact that built environment results from the consistent standards and technologies of architects, this study inquires into the systematic standard and its formation that present in the process of planning for the overall scale and shape of a building from the following (four) perspectives. The study determines the characteristics of '間(Kan)' (unit; fundamental unit that measures Korean traditional houses) and the methods of columns disposition of which the '間 (Kan)' is made up. Once the necessary spaces are decided according to the size of a building, then floor plans are drawn with the standard unit, '間(Kan)'. The '間(Kan)', as a modular unit, is not only composing the floor plans, but also functioning as an Area unit, Space unit and Structural unit. Composition of '間(Kan)' varies with disposition of columns, and therefore multiform of floor and spaces are created. In this study, the '間(Kan)', as a standard unit, is used in the form of specific size and area, and it is demonstrated how the floor plans are developed by organizing the columns in accordance with the spaces requested.

PRAM용 GST계 박막의 조성에 따른 특성 (Properties of GST Thin Films for PRAM with Composition)

  • 정명훈;장낙원;김홍승;류상욱;이남열;윤성민;박영삼;이승윤;유병곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.203-204
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    • 2005
  • PRAM (Phase change Random Access Memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change material has been researched in the field of optical data storage media. Among the phase change materials $Ge_2Sb_2Te_5$(GST) is very well known for its high optical contrast in the state of amorphous and crystalline. However, the characteristics required in solid state memory are quite different from optical ones. In this study, the structural properties of GST thin films with composition were investigated for PRAM. The 100-nm thick GeTe and $Sb_2Te_3$ films were deposited on $SiO_2$/Si substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films, we performed x-ray diffraction (XRD) and atomic force microscopy (AFM).

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