• Title/Summary/Keyword: Composition structural system

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

  • Min, Byeong-Joo;Choi, Hyung-Don;Kang, E-Sok
    • Aerospace Engineering and Technology
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    • v.7 no.1
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    • pp.151-160
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    • 2008
  • In this paper, the analysis results of synthetic resonance characteristics are described for the electrohydraulic thrust vector control actuation system. The synthetic resonance is induced by integration of position servo actuation system on the flexible launch vehicle mounting structure. The new resonance mode is synthesized due to composition of hydraulic resonance for electrohydraulic position servo system with inertia load condition and structural resonance for flexible mounting structure. This synthetic resonance can make stability of control system worse by feedback and amplification of control system. The exact nonlinear analysis model of this phenomenon is developed to predict and design a control algorithm for improvement characteristics. The DPF (Dynamic Pressure Feedback) control algorithm has been designed and has excellent resonance suppression capability.

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

  • Hwang, Seong-Jin;Won, Ju-Yeon;Kim, Hyung-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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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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A study on the Buddist Temple Space through the religious composition (신앙구조(信仰構造)를 통해 본 사찰공간(寺刹空間) 구성(構成)에 관한 연구(硏究))

  • Kim, Seung-Je;Kim, Jin -Duck
    • Journal of the Korean Institute of Rural Architecture
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    • v.4 no.3
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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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A Study on Properties of $CuInS_{2}$ thin films by Cu/In ratio (Cu/In 비에 따른 $CuInS_{2}$ 박막의 특성에 관한 연구)

  • Yang, Hyeon-Hun;Kim, Young-Jun;Jeong, Woon-Jo;Park, Gye-Choon
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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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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Preparation of Composite Polycrystals Including ${\gamma}$-$6Bi_2O_3$.$SiO_2$ (${\gamma}$-$6Bi_2O_3$.$SiO_2$ 결정을 포함하는 복합다결정체의 작성)

  • 김호건
    • Journal of the Korean Ceramic Society
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    • v.23 no.2
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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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Properties of GST Thin Films for PRAM with Composition (PRAM 용 GST계 상변화 박막의 조성에 따른 특성)

  • Jang Nak-Won
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.6
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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 $125^{\circ}C$.

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

  • Yang, Hyeon-Hun;Kim, Young-Jun;Jeong, Woon-Jo;So, Soon-Youl;Lee, Jin;Chung, Hae-Deok;Park, Gye-Choon;Choi, Yong-Sung;Lee, Gyung-Sup
    • Proceedings of the KIEE Conference
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    • 2008.07a
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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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Dielectric Properties of $BaTiO_3$ System Ceramics for Microwave Phased Shifter (위상 변위기용 $BaTiO_3$계 세라믹의 유전특성)

  • Lee, Sung-Gap;Park, Sang-Man;Park, In-Gil;Lim, Sung-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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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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A Study on Planning and Composition of Module Unit in Korean Traditional House (전통한옥 '칸'의 계획과 구성에 관한 연구)

  • Kim, Jong-Hoon
    • Journal of the Korean housing association
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    • v.23 no.4
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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.

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

  • Jung, Myung-Hun;Jang, Nak-Won;Kim, Hong-Seung;Ryu, Sang-Ouk;Lee, Nam-Teal;Yoon, Sung-Min;Park, Young-Sam;Lee, Seung-Yun;Yu, Byoung-Gon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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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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