• 제목/요약/키워드: Post-structural

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RC 부재의 휨 보강을 위한 외부 부착형 탄소섬유판 포스트텐션 시스템 (Post-tensioning System with Externally Bonded CFRP Strips for Strengthening RC Members)

  • 유영찬;최기선;김긍환
    • 한국구조물진단유지관리공학회 논문집
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    • 제12권6호
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    • pp.155-163
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    • 2008
  • 본 연구에서는 외부 부착 프리스트레스트 탄소섬유판으로 보강된 RC보의 휨거동을 분석하기 위한 실험연구를 수행하였다. 실험체는 프리스트레스 양을 변수로 축소모형으로 제작되었다. 또한 프리스트레스의 도입에 따른 구조성능 비교를 위하여 기준실험체와 단순부착 실험체를 함께 제작하였다. 실험결과, 단순 부착 탄소섬유판으로 보강된 부재는 조기 박리에 의해 탄소섬유판 인장강도의 50% 이하에서 최종파괴되었다. 그러나, 프리스트레스를 도입하여 보강한 실험체는 모두 탄소섬유판의 파단하중까지 도달하였다. 또한 프리스트레스 보강량의 증가에 따라서 균열하중, 항복하중은 증가하며 최대하중은 프리스트레스 양과 관계없이 일정한 것으로 나타났다.

폭렬 현상을 고려한 RC 구조물의 PBD기반 구조내화설계 기술개발에 관한 연구(III) -일본의 내화안전성평가기법을 활용한 사례조사 연구- (A Study on the Structural Fire Resistance Performance Design of RC Structural according to the Explosive Spalling - A Case Study on the Evaluation Method of Structural Fire Resistance in Japan -)

  • 김세종;이재영;권영진
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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    • pp.310-315
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    • 2008
  • The objective of design for a post flash-over fire is contain the fire and prevent structural collapse, as necessary to meet the performance requirements. In the post flash-over phase of a fire all of the combustible objects in the compartment are burning and the heat release rate is limited either by the fuel surface area or the available air supply. So for the PBD situations, the process of evaluation method for fire phenomena is very important. It is the aim of this study to investigate and analyze the evaluation method of structural fire resistance in Japan.

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Effects of the buffer layer annealing and post annealing temperature on the structural and optical properties of ZnO nanorods grown by a hydrothermal synthesis

  • 신창미;류혁현;이재엽;허주회;박주현;이태민;최신호
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2009년도 춘계학술발표대회
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    • pp.24.1-24.1
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    • 2009
  • The zinc oxide (ZnO) material as the II-VI compound semiconductor is useful in various fields of device applications such as light-emitting diodes (LEDs), solar cells and gas sensors due to its wide direct band gap of 3.37eV and high exciton binding energy of 60meV at room temperature. In this study, the ZnO nanorods were deposited onto homogenous buffer layer/Si(100) substrates by a hydrothermal synthesis. The Effects of the buffer layer annealing and post annealing temperature on the structural and optical properties of ZnO nanorods grown by a hydrothermal synthesis were investigated. For the buffer layer annealing case, the annealed buffer layer surface became rougher with increasing of annealing temperature up to $750^{\circ}C$, while it was smoothed with more increasing of annealing temperature due to the evaporation of buffer layer. It was found that the roughest surface of buffer layer improved the structural and optical properties of ZnO nanorods. For the post annealing case, the hydrothermally grown ZnO nanorods were annealed with various temperatures ranging from 450 to $900^{\circ}C$. Similarly in the buffer layer annealing case, the post annealing enhanced the properties of ZnO nanorods with increasing of annealing temperature up to $750^{\circ}C$. However, it was degraded with further increasing of annealing temperature due to the violent movement of atoms and evaporation. Finally, the buffer layer annealing and post annealing treatment could efficiently improve the properties of hydrothermally grown ZnO nanorods. The morphology and structural properties of ZnO nanorods grown by the hydrothermal synthesis were measured by atomic force microscopy (AFM), field emission scanning electron microscopy (SEM), and x-ray diffraction (XRD). The optical properties were also analyzed by photoluminescence (PL) measurement.

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포스트구조주의적 분석을 이용한 간호와 보건의료의 역사에 대한 재해석의 한 시도 (An Attempt of Reinterprtation on History of Nursing and Health Care Using Post-structural Method)

  • 김남선
    • 대한간호학회지
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    • 제27권3호
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    • pp.531-540
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    • 1997
  • The purpose of this study is to reinterpretate the history of nursing and health care from the view-point of post-structuralism. It has been emphasized that the development of modern health care has been due to the progressive efforts of medicine and to medical discoveries. Medicine has dominated the history of health care rather than nursing or other health professions. The present study adopts the post-structural method by Foucault, which tries to unite language and knowledge. Foucault examines "the institutionalization of knowledge and the power exerted thereby, with special reference to the devices of social regulation and their function over the madness, the disease, the crime, and the sexuality. " The concept of power in Foucault's writing is that it is exerted spontaneously in verbal behaviors of individuals through knowledge of everyday life such as definition of body or mind, sexuality and relationship of family. Therefore as to the problem of power, this study tries to understand the meaning of the health care history through an analysis of the formation of medical discourse. In order to have authority in a power relation, the medical professional asserts that medical discourse is the most scientific knowledge. The authority of medical professionals can be reinforced by the fact that male medical professionals outnumber female. Devaluation of nursing care is reinforced by the medicine which has the legitimate authority through use of the political skills.

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자전거 서스펜션 안장봉에 대한 구조 안정성 해석 (Structural Safety Analysis on Bicycle Suspension Seat Post)

  • 한문식;조재웅
    • 한국기계가공학회지
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    • 제11권4호
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    • pp.72-81
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    • 2012
  • This study investigates structural, fatigue and modal analyses at bicycle suspension seat post. When weight is applied to the saddle, models 1 and 2 have the weakest strength at the part connected with saddle. And model 2 is greater total deformation and equivalent stress than model 1. Among the cases of nonuniform fatigue loads at models 1 and 2, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to $-10^4MPa$ and the amplitude stress of 0 to $10^4MPa$, the possibility of maximum damage becomes 4%. This stress state can be shown with 5 to 7times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. Model 1 has better impulse relaxation and passenger sensitivity than model 2. The structural result of this study can be effectively utilized with the design of bicycle suspension seat post by investigating prevention and durability against its damage.

외부 포스트텐셔닝공법에 의한 콘크리트 구조물의 보강사례 연구 (Reinforcement of RC Structures with External Post-Tensioning Method)

  • 정원용;김승익
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.387-392
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    • 2002
  • In many years, post-tensioning method has been used for structural reinforcement of RC structures due to easy installation and good quality control. This study presents practical application results for the effectiveness of structural post-tensioning reinforcement of the FCM bridge girders, cement silos and building girders. For the FCM bridges deflected excessively at the end of girders, for cement silos cracked vertically at silo surface and for building girders deflected due to heavy load from roof, the external post-tensioning method was used for uplifting deflected girders and closing cracks with increasing resisting capacity of the structures. It was demonstrated that all the items were rehabilitated nearly to the initial construction status according to the field test results.

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사파이어 기판 위에 증착된 ZnO 박막의 후열처리에 따른 발광특성 연구 (Effects of post-annealing treatment at various temperature on the light emission properties of ZnO thin films on sapphire)

  • 강홍성;심은섭;강정석;김종훈;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.119-122
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    • 2001
  • ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition(PLD) technique at the oxygen pressure of 350 mTorr. In order to investigate the effect of post-annealing treatment with oxygenn pressure of 350 mTorr on the optical property of ZnO thin films, films have been annealed at various substrate temperatures after deposition. After post-annealing treatment in the oxygen ambient, the optical properties of the ZnO thin films were characterized by PL(Photoluminescence) and structural properties of the ZnO were characterized by XRD, and have investigated structural property and optical property for application of light emission device.

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객체지향 기법을 이용한 RC통합 구조설계 시스템의 후처리 모듈 개발 (Development of Post-processing Modules in an Integrated System for Reinforced Concrete Structures Using Object-Oriented Techniques)

  • 이진우;천진호;김우범;이병해
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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    • pp.352-361
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    • 1998
  • The post-processing modules are parts of an integrated system for reinforced concrete structures. This modules are composed of two modules: member design module and calculation report module. The purpose of this paper is to develope modules that increase efficiency and usefulness of an integrated system used reinforced concrete structures design. The development of post-processing modules is necessary for user to design reinforced concrete structures conveniently and quickly. This modules are connected with central database for the benefit of storing amount of input/output data and being used system with little effort. Post-processing modules used Object-Oriented concepts and techniques include identity, classification, polymorphism, and inheritance. Member design module automatically converts no good members into satisfied members by changing section size or reinforcement bar arrangement. This module can be operated both independent member design modules with user input and a part of integrated system with database input. If user operates member design module, calculation report module is created automatically.

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포스트 텐션 플랫 플레이트 슬래브 접합부의 거동 (Structural Behavior of Post-Tensioned Flat Plate Slab-Column Connections)

  • 조경현;한상환;이리형
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.53-56
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    • 2004
  • Recently, post tension flat plate slab system is widely used for a new slab structural system. Slab-column connections may fail in brittle manner by punching shear. Flat plate slabs have been widely used for gravity load resisting system in buildings. Lateral resistance usually provided by shear walls or moment resisting frames. Since plat plates move together with lateral loading system during earthquake or wind, it is important to evaluate the gravity resistance under a drift experienced by lateral force resisting system during either design earthquake or wind. Thus, this study investigated post tension flat plate slab systems whether they have sufficient strength and deformability to resist gravity loads during specified drift levels. Experimental research was carried out.

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