• 제목/요약/키워드: Sectional property

검색결과 113건 처리시간 0.022초

Varification of Phase Defect Correctability of Nano-structured Multilayer for EUV Reflection

  • Lee, Seung-Yoon;Kim, Tae-Geun;Jinho Ahn
    • 한국진공학회지
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    • 제12권S1호
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    • pp.40-45
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    • 2003
  • Ru interfacial layer was inserted into Mo-on-Si interface to enhance the extreme ultra-violet (EUV) reflective multilayer properties. The stacking status and optical properties are analyzed using cross-sectional transmission electron microscope (TEM), and reflectometer. About 1.5% of maximum reflectivity can be acquired as predicted in optical simulation, which is thought to be originated from the diffusion inhibition property. Phase defect correctability of the multilayer can be enhanced by the insertion of Ru barrier layer.

지역사회 한방건강증진사업을 위한 조사연구 (Survey on Community Oriental Health Promotion Program)

  • 박송자
    • 재활간호학회지
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    • 제9권2호
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    • pp.153-160
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    • 2006
  • Purpose: This study was performed to examine present health condition on community clients and the degree of cognition on community oriental health promotion program. Method: Research design is cross-sectional descriptive study, 300 residents who live in S city were selected. The period of data collection was from October 2005 to April 2006. The research instruments used were the VAS of fatigue, headache, pain, Depression, anxiety to examine present physical and psychological health condition and questionnaire on the degree of cognition on Oriental Health Promotion Program. SPSS 10.0 was used for statistics. Results: The range of fatigue, headache, pain, depression, anxiety was 2.09-3.75. The degree of cognition on program was 2.67. As for the degree of cognition on oriental health promotion program according to general characteristics of subject, there was significant difference(F=3.79, p=.038) between below 65 years(2.88) and above 65 years(3.12). Conclusion: We are trying to develop oriental health promotion program fit to property of community, especially elderly.

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Ultimate strength of long-span buildings with P.E.B (Pre-Engineered Building) system

  • Lee, Seong-Hui;Kim, Young-Ho;Choi, Sung-Mo
    • Steel and Composite Structures
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    • 제19권6호
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    • pp.1483-1499
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    • 2015
  • With the improvement of the quality of construction materials and the development of construction technologies, large-scale long-span steel frame buildings have been built recently. The P.E.B system using tapered members is being employed as an economically-efficient long-span structure owing to its advantage of being able to distribute stress appropriately depending on the size of sectional areas of members. However, in December 2005 and in February 2014, P.E.B buildings collapsed due to sudden loads such as snow loads and wind gusts. In this study, the design and construction of the P.E.B system in Korea were analyzed and its structural safety was evaluated using the finite element analysis program to suggest how to improve the P.E.B system in order to promote the efficient and rational application of the system.

골조구성 변단면 기둥의 유효길이 계수 (Effective length factors for the framed columns with variable stiffness)

  • 이수곤;김순철;오금열
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.175-182
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    • 2001
  • Effective length factor approach for framed column design has long played an important design-aid role. This approach, however, is effective only when the columns are in the form of prismatic or uniform cross sections. Structural engineers who have to design or analyse framed columns with variable cross sections need some means to do their job. By using the finite element method, the stability analysis of the isolated compression members with variable cross sections and that of the framed columns are performed. The parameters considered in the stability analysis are taper and sectional property parameters of the columns, the second moment of inertia ratio of beam to column, and beam span to column height ratio. On the basis of the stability analysis results, effective length factor formulas for the columns with variable sections are derived.

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대칭형으로 taper진 압축재의 등가 단면2차모멘트 (The equivalent second moment of area for the symmetrically tapered compression member)

  • 김상조;민영숙;김순철;이수곤
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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    • pp.291-298
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    • 2001
  • When the compression members have the variable cross sections along their member axes, the determination of the elastic critical loads by classical methods becomes impossible and if possible involves complicated calculation only to obtain the approximate values of critical load. In this paper the elastic critical load coefficients of the tapered members with simply supported ends were determined by finite element method. And then the results were represented by simple algebraic equations of two parameters, a( =taper parameter) and m ( = sectional property parameter). One the basis of algebraic equations, the equivalent moment of inertia concept originally proposed by Bleich for a spesific case, are extended to the general cases.

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변단면 압축재의 임계하중 (Elastic Critical Load of Tapered Columns)

  • 김태순;홍종국;김순철;이수곤
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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    • pp.421-428
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    • 1999
  • The elastic critical load of a slender compression member plays an important role when the proper design of that member is required. For the tapered compression members, however, there are cases when the conventional neutral equililbrium or energy method can't be applied to the determination of critical loads of those members. In this paper, finite element method is applied to the approximate determination of the symmetrically tapered bars. Here in this paper, the bars are assumed to take sinusoidally changing shapes along their axes. The parameters considered in this study are taper parameter, $\alpha$ and the sectional property parameter, m. The computed results by finite element method are represented in the forms of algebraic equations. Regression technique is employed to determine the coefficients of algebraic equations. The critical loads estimated by the proposed algebraic equations coincide fairly well with those of finite element method.

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직선형으로 Taper진 비대칭 변단면 부재의 탄성임계하중 (The Elastic Critical Loads of Linearly Non-symmetrically Tapered Members)

  • 김효중;홍종국;이수곤
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
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    • pp.299-306
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    • 2000
  • The elastic critical load of a slender compression member plays an important role when the proper design of that member is required. For tapered compression members, however, there are cases when the conventional neutral equilibrium or energy method can't be applied to the determination of critical loads. In this paper, the finite element method is applied to the approximate determination of the linearly tapered members. In this paper, the bars are assumed to be tapered linearly along their axes. The parameters considered in this study are taper parameter, α and the sectional property parameter, m. The member ends are either hinged or fixed. The computed results using the finite element method are represented in the forms of algebraic equations. The regression technique is employed to determine the coefficients of the algebraic equations. Critical loads estimated by the proposed algebraic equations coincide flirty well with those employing the finite element method.

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다중스케일 기법을 이용한 카본나노튜브 복합재료의 물성치 계산 (Estimation of material properties of carbon nanotube composite applying multi-scale method)

  • 김정택;현석정;김철
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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    • pp.165-168
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    • 2004
  • Carbon nanotube is a geometrical frame-like structure and the primary bonds between two nearest-neighboring atoms act like beam members, whereas an individual atom acts as the joint of the related beam members. The sectional property parameters of these beam members are obtained from molecular mechanics. Computations of the elastic deformation of single-walled carbon nanotubes reveal that the Young's moduli of carbon nanotubes vary with the tube diameter and are affected by their helicity. With increasing tube diameter, the Young's moduli of carbon nanotubes approach the Young's modulus of graphite.

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콘크리트 터널 라이닝 배면공동의 깊이 및 두께변화에 따른 전자파 레이더의 반사파 특성 (Reflection Wave Property of Electromagnetic Radar according to Change of Depth and Thickness of Voids under Concrete Tunnel Lining)

  • 박석균
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.789-792
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    • 2004
  • This study aims to detect only voids and estimate the cross-sectional size and thickness of voids using radar. A new method based on radar image processing is carried out with various void sizes and depths. The regression relationship between void size which has different depth and the amplitude characteristics of the radar return is considered in a new method of this research. For the purpose of examining; this regression relationship, experiments with change of void depth, surface area and thickness were carried out. Finally, the threshold value for image processing which aims to represent only voids to be fitted size (width) can be obtained. As the results, a proposed method in this study has a possibility of detecting only voids and estimating void size and thickness with good accuracy.

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소오스/드레인 영역의 도펀트 양의 증가에 따른 코발트실리사이드의 물성변화 (Influence of Dose on the Property of Cobalt Silicides in Source/Drain Area)

  • 정성희;송오성;김민성
    • 한국재료학회지
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    • 제13권1호
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    • pp.43-47
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    • 2003
  • As and BF$_2$dopants are implanted for the formation of source/drain with dose of 1${\times}$10$^{15}$ ions/$\textrm{cm}^2$∼5${\times}$10$^{15}$ ions/$\textrm{cm}^2$ then formed cobalt disilicide with Co/Ti deposition and doubly rapid thermal annealing. Appropriate ion implantation and cobalt salicide process are employed to meet the sub-0.13 $\mu\textrm{m}$ CMOS devices. We investigated the process results of sheet resistance, dopant redistribution, and surface-interface microstructure with a four-point probe, a secondary ion mass spectroscope(SIMS), a scanning probe microscope (SPM), and a cross sectional transmission electron microscope(TEM), respectively. Sheet resistance increased to 8%∼12% as dose increased in $CoSi_2$$n^{+}$ and $CoSi_2$$p^{V}$ , while sheet resistance uniformity showed very little variation. SIMS depth profiling revealed that the diffusion of As and B was enhanced as dose increased in $CoSi_2$$n^{+}$ and $CoSi_2$$p^{+}$ . The surface roughness of root mean square(RMS) values measured by a SPM decreased as dose increased in $CoSi_2$$n^{+}$ , while little variation was observed in $CoSi_2$$p^{+}$ . Cross sectional TEM images showed that the spikes of 30 nm∼50 nm-depth were formed at the interfaces of $CoSi_2$$n^{+}$ / and $CoSi_2$/$p^{+}$, which indicate the possible leakage current source. Our result implied that Co/Ti cobalt salicide was compatible with high dose sub-0.13$\mu\textrm{m}$ process.