• 제목/요약/키워드: Flexible structure

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연성포장에서 노상재료로서 EPS지오폼의 회복탄성계수의 모델에 관한 분석적 연구 (Analytical Study on Resilient Modulus Model of Expanded Polystyrene(EPS) Geofoam as a Subgrade Material in Flexible Pavement)

  • 박기철;장용채
    • 한국지반환경공학회 논문집
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    • 제13권9호
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    • pp.61-68
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    • 2012
  • 본 연구의 주된 목적은 EPS지오폼이 연성포장의 노반재료로 사용될 때 그것의 회복탄성계수를 해석 모델화 하는 것이다. 이 해석모델은 삼축압축 시험으로부터 나온 실험결과를 토대로 만들어졌다. 그리고 이 모델은 원하는 용도에 따라서, 기존의 프로그램을 수정하거나 새로 개발하여 유한요소법을 이용한 연성포장구조를 해석하는데 사용될 수 있다. 또한 본 연구의 결과는 연성포장에서의 현장 연약지반 노상재료의 대체물로서 EPS지오폼은 적합한 것으로 확인되었다.

Highly Sensitive Flexible Organic Field-Effect Transistor Pressure Sensors Using Microstructured Ferroelectric Gate Dielectrics

  • 김도일;이내응
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.277.2-277.2
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    • 2014
  • For next-generation electronic applications, human-machine interface devices have recently been demonstrated such as the wearable computer as well as the electronic skin (e-skin). For integration of those systems, it is essential to develop many kinds of components including displays, energy generators and sensors. In particular, flexible sensing devices to detect some stimuli like strain, pressure, light, temperature, gase and humidity have been investigated for last few decades. Among many condidates, a pressure sensing device based on organic field-effect transistors (OFETs) is one of interesting structure in flexible touch displays, bio-monitoring and e-skin because of their flexibility. In this study, we have investigated a flexible e-skin based on highly sensitive, pressure-responsive OFETs using microstructured ferroelectric gate dielectrics, which simulates both rapidly adapting (RA) and slowly adatping (SA) mechanoreceptors in human skin. In SA-type static pressure, furthermore, we also demonstrate that the FET array can detect thermal stimuli for thermoreception through decoupling of the input signals from simultaneously applied pressure. The microstructured highly crystalline poly(vinylidene fluoride-trifluoroethylene) possessing piezoelectric-pyroelectric properties in OFETs allowed monitoring RA- and SA-mode responses in dyanamic and static pressurizing conditions, which enables to apply the e-skin to bio-monitoring of human and robotics.

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비정질 IZO 애노드 박막을 이용한 플렉서블 유기발광소자 특성 (Characteristics of amorphous IZO anode based flexible organic light emitting diodes)

  • 문종민;배정혁;정순욱;김한기;강재욱
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.491-492
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    • 2006
  • We report on the fabrication of organic-based flexible display using an amorphous IZO anode grown at room temperature. The IZO anode films were grown by a conventional DC reactive sputtering on polycarbonate (PC) substrate at room temperature using a synthesized IZO target in a Ar/$O_2$ ambient. X-ray diffraction examination results show that the IZO anode film grown at room temperature is complete amorphous structure due to low substrate temperature. It is shown that the $Ir(ppy)_3$ doped flexible organic light emitting diode (OLED) fabricated on the IZO anode exhibit comparable current-voltage-luminance characteristics to OLED fabricated on conventional ITO/glass substrate. These findings indicate that the IZO anode film grown on PC substrate is a promising anode materials for the fabrication of organic based flexible displays.

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지지구조와 액츄에이터의 유연성을 고려한 HDD 유연 회전 디스크-스핀들 시스템의 유한 요소 고유 진동 해석 (Finite Element Modal Analysis of a Spinning Flexible Disk-Spindle System Considering the Flexiblity of Supporting Structures and an Actuator in a HDD)

  • 서찬희;이창석;장건희;이호성
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.330-336
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    • 2005
  • This paper presents a method to analyze the vibration of a flexible spinning disk-spindle system with FDBs, flexible base structure and an actuator in a HDD by using the FEM. Finite element equations of each component of a HDD spindle system from the spinning flexible disk to the flexible base plate are consistently derived by satisfying the geometric compatibility in the internal boundary between each component. A global matrix equation obtained by assembling the finite element equations of each substructure is transformed to a state-space matrix-vector equation, and both damped natural frequencies and modal damping ratios are calculated by using the restarted Arnoldi iteration method. The validity of the proposed method is verified by comparing the simulated natural frequencies, mode shapes with the experimental results.

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유연한 벽면을 가진 사각형 물탱크의 설계지진력 산정 (Seismic Design Force for Rectangular Water Tank with Flexible Walls)

  • 김민우;유은종;박지훈
    • 한국지진공학회논문집
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    • 제27권6호
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    • pp.303-310
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    • 2023
  • The equivalent static load for non-structural elements has a limitation in that the sloshing effect and the interaction between the fluid and the water tank cannot be considered. In this study, the equations to evaluate the impulse and convective components in the design codes and previous research were compared with the shaking table test results of a rectangular water tank with flexible wall panels. The conclusions of this study can be summarized as follows: (1) It was observed that the natural periods of the impulsive component according to ACI 350.3 were longer than system identification results. Thus, ACI 350.3 may underestimate the earthquake load in the case of water tanks with flexible walls. (2) In the case of water tanks with flexible walls, the side walls deform due to bending of the front and back walls. When such three-dimensional fluid-structure interaction was included, the natural period of the impulsive component became similar to the experimental results. (3) When a detailed finite element (FE) model of the water tank was unavailable, the assumption Sai = SDS could be used, resulting in a reasonably conservative design earthquake load.

국내외 장스팬 구조물의 고유진동수 비교 (Comparison of Natural Frequency of Domestic and Foreign Long-spaned Structure)

  • 윤성원;박용
    • 한국공간구조학회논문집
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    • 제9권1호
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    • pp.79-85
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    • 2009
  • 최근의 대공간구조물은 장스팬화 됨은 물론이고 경량화되면서 면외 방향의 강성이 매우 작아지고 있다. 이로 인하여 공력불안정 진동의 발생 여부는 물론이고 연성구조물의 판단시에도 고유진동수의 정확한 산정이 필요하다. 그러나 국내외 대공간구조물의 고유진동수 제안식에 대한 연구는 매우 미흡한 실정이다. 따라서 국내 7개 공간구조물의 고유치해석에서 얻은 근사식을 일본건축학회 고유치해석에 근거한 2가지 제안식과 일본의 28개 공간구조물의 계측치에서 얻은 고유진동수 근사식을 비교하였다. 지붕의 고유진동수는 스팬이 증가함에 따라서 작아지는 경향을 확인하였다. 국내의 고유진동수 값은 전반적으로 일본의 공간구조물의 해석과 계측에 근거한 고유진동수보다 동일한 스팬에서 작은 경향을 보임을 알 수 있었다. 따라서 국내 공간구조물의 지붕은 일본의 경우보다 비교적 연성구조물인 것을 확인할 수 있다.

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프레스 박판 소재의 취급성 (Handling of Polyethylene Sheet Plate in Press Process)

  • 목학수;김경윤
    • 산업공학
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    • 제7권2호
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    • pp.145-155
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    • 1994
  • In this paper, we analyzed weak points of press process with the rolled thin flexible plate. The problems which are caused by the adhesion of blank on the surface of die and the separation of blank from scrap during its transportation after blanking were solved by the redesign of the structure of die and the development of special equipment for material handling. It is our purpose to make better the automation of blanking process and the safety for worker by the improvement of flexible material handling.

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직육면체 공동 내부의 소음 저감을 위한 능동 구조-음향 연성제어

  • 이상원;황철호;이장무
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.218-223
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    • 1997
  • The technique used is the active structural acoutrol (ASAC)approach which involves controlling the acoustic response of a panel-cavity covpled system by applying oscillating force inputs in the form of prezoelectric actuators directly to the flexible panel. The linear quadratic Gaussian control scheme is used for attenuating nosie inside the rectangular enclosure causing by flexible wall vibration. Results indicated the application of control inputs to the radiating wall resukted in considerable noise reductions inside the cavity. Auso,the possibility of application to the more complicated fluid-structure coupled system is verified.

사이버 공간에서의 신뢰성 확보 방안 - 기업 내부관점에서 - (Trust Building in Cyberspace)

  • 박경환
    • 한국디지털정책학회:학술대회논문집
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    • 한국디지털정책학회 2003년도 창립학술대회
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    • pp.403-415
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    • 2003
  • This study is performed to examine the relationships between trust and antecedents in cyberspace. Trust is the major control system in cyberspace. Different time, different spaces, different cultures, indistinct boundaries, flexible structure, separation of information from matters, cybernetics, difficulty of control are differential characteristics between cyberspace and physical space. Providing fit information, use of effective electronic channels, previous trust management, feedback system about output, flexible culture, self-regulation, off-line meeting, providing information about tasks and roles, ability, and justice are supposed to have effects on trust in cyberspace. By electronic mediated systems, the company will have more business opportunity. But trust will be conditional factors of expanding business in cyberspace.

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