• 제목/요약/키워드: resistive

검색결과 1,189건 처리시간 0.025초

Fire Behavior of Steel Columns Encased by Damaged Spray-applied Fire Resistive Material

  • Kwak, Yoon Keun;Pessiki, Stephen;Kwon, Kihyon
    • Architectural research
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    • 제10권1호
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    • pp.1-11
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    • 2008
  • A Steel column with damaged spray-applied fire resistive material (SFRM) may exhibit reduced structural performance due to the effects of elevated temperature during fire events. Thus, the fire load behavior of steel columns with removed or reduced SFRM needs to be examined to predict the structural damage by fire. FEM analyses were performed for the flange thinning removal models in which the SFRM was reduced as a constant strip in thickness at the top flange of the column. The temperature results for all models obtained from the heat transfer analyses were included as an initial condition in the FEM structural analyses. In this study, the results of analysis show that even small remnants of SFRM led to an effective reduction of temperature at any given fire duration, and improved significantly the axial load capacity of a column as compared to the complete removal cases of SFRM.

광대역 주파수를 가진 전력 측정 변환기 (A Watt-Converter for a Wideband Frequency Power Measurement)

  • 박영태;강전홍;정재갑;유권상
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제53권10호
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    • pp.597-601
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    • 2004
  • A high bandwidth watt-converter, based on an inexpensive, commercially available, standard IC package, is described that covers a frequency ranges from DC to 100 kHz. The new resistive shunt for a wide-band frequency current measurement of the watt-converter was developed. The converter will use application in accurate power measurement under distorted and high frequency conditions. The advantages of the proposed watt-converter are its simplicity, low cost and fast response time.

고온초전도체를 이용한 차폐유도형 전류제한기의 설계 및 동작 특성해석 (The design and analysis of Operational characteristic of Shielded Inductive Fault Current Limiter using high-$T_c$ Superconducting)

  • 송재주;이재;임성훈;강형곤;한병성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.339-342
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    • 2001
  • In this paper, the characteristics of the shielded inductive superconducting fault current limiter(FCL) were simulated and analyzed to search for the parameter to determine FCL operation, Fault current limiting operation can be executed as resistive or inductive type, which is determined by iron-core radius and the number of the primary coil turns. It was considered through this paper that the operation of each was compared and examined about the merit of each mode.

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Organic Bistable Switching Memory Devices with MeH-PPV and Graphene Oxide Composite

  • Senthilkumar, V.;Kim, Yong Soo
    • Transactions on Electrical and Electronic Materials
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    • 제16권5호
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    • pp.290-292
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    • 2015
  • We have reported about bipolar resistive switching effect on Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]:Graphene oxide composite films, which are sandwiched between aluminum and indium tin oxide electrodes. In this case, I-V sweep curve showed a hysteretic behavior, which varied according to the polarity of the applied voltage bias. The device exhibited excellent switching characteristics, with the ON/OFF ratio being approximately two orders in magnitude. The device had good endurance (105 cycles without degradation) and long retention time (5 × 103 s) at room temperature. The bistable switching behavior varied according to the trapping and de-trapping of charges on GO sites; the carrier transport was described using the space-charge-limited current (SCLC) model.

반비례적으로 변하는 저항율을 갖는 반평면에 의한 H 분극산란 (H-Polarized Scattering by an Inversely Tapered Resistive Half Plane)

  • 양승인;나정웅
    • 대한전자공학회논문지
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    • 제26권7호
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    • pp.1-7
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    • 1989
  • 가장자리로 부터 역비례로 저항률이 변하는 반평면에 H분극 평면파가 입사되는 경우, 산란파를 Kontorovich-Lebedev 변환을 이용해서 정확한 적분식으로 얻었으며, 이로부터 모든 각도에서 쓸 수 있는 균일 근사식 및 계산된 산란파를 광선적(光線的)으로 해석할 수 있도록 해주는 비균일 근사식도 구했다. 저항율의 상수 여러 값에 대하여 가장자리 회절 패턴을 보였다. 결과들은 물리적으로 타당함을 알 수 있었다.

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송.배전급 저항형 초전도 한류기 설계 요소 검출을 위한 고온 초전도 선재의 특성 연구 (Experimental Study on the High Temperature Superconductor for Investigated Design Factors of Distribution and Transmission Level Resistive Type Superconductor Fault Current Limiter)

  • 나진배;장재영;조현철;황영진;고태국
    • 한국초전도ㆍ저온공학회논문지
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    • 제13권3호
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    • pp.10-13
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    • 2011
  • The power demand is steadily increasing due to rapidly develop of industrial field. The ratio of prospected increment of power consumption is over 2.2 % per year from 2007 to 2020 year. The superconducting fault current limiters(SFCLs) should be suggested to be one of promising machines to protect power grid. Four basis tests such as resistivity, short-circuit tests, ac losses and recovery time were investigated according to various reached maximum temperature, operating temperature. This paper deals with investigation of the various commercial high temperature superconductor for applying resistive type SFCLs.

센서유형별 측정 변형률을 이용한 철근콘크리트 보의 처짐추정에 관한 실험적 연구 (An experimental study on estimating deflection of RC beam using resistive strain gauge and fiber optic sensor)

  • 이규완;박기태;박흥석
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.517-522
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    • 2000
  • In the past few years, the nondestructive inspection technology has greatly developed due to the increased necessity to gain a complete understanding of the bridge behavior. Especially, the deformations of bridges contain a lot of informations about its health state. By measuring these deformations it is possible to analyze the loading and aging behavior of the structure. However, the current methods (such as LVDT, dial gage, optical displacement tranceducer, etc) are often of changeable application on site and have the limitations of installation. In this paper, the classical beam theory was reviewed and the deflections of structure are estimated using measured strain which is easy to acquire. The applicability of this algorithm is verified by a preliminary steel beam test and two types of concrete beam tests. Also fiber optic sensors as well as resistive strain gages were installed in the concrete beams to establish the applicability of fiber optic sensors in the field of civil engineering.

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옥내용 뿜칠내화피복재의 촉진내구성 조건 설정 연구 (Development of Acceleration Duability test condition for Fireproof Spray-Application.)

  • 김대회;이건철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.170-171
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    • 2014
  • The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. This study is covers standardization of the methods for assessing the durability of SFRM. In Korea, more than 90 percent of SFRM are used indoors. So This study is to decide proper test method through investigation and examination of effect factor to performance of fire-resistant structure and applicable test method.

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A Study on Switching Shunt Regulator for Satellite Power System

  • Park, Jae-dong;Seong, Se-Jin
    • Journal of Electrical Engineering and information Science
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    • 제3권1호
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    • pp.14-20
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    • 1998
  • The resistive shunting for the fine control of a Direct Energy Transfer(DET) systems is fully developed, but the non-resistive shunting using variable size solar array segments is in progress. This paper presents the spacecraft power control through switching of solar array segments, which uses a fully regulated DET power regulation. This method eliminates a dissipative element and removes the associated design limitations which arise from the dissipative elements for radiating cooling in deep space. The switching shunt regulator comprises the switched Solar Array Shunt(SAS) modules that regulate the solar array power. These SAS modules connect/disconnect the solar array segments to/from the bus according to the loading in the main bus without significant variations in the dissipation level. In this paper, twelve segments are used in the shunting. In order to verify the basis of analysis, the computational result of an analytic loop gain is performed.

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Evolution of Nonvolatile Resistive Switching Memory Technologies: The Related Influence on Hetrogeneous Nanoarchitectures

  • Eshraghian, Kamran
    • Transactions on Electrical and Electronic Materials
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    • 제11권6호
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    • pp.243-248
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    • 2010
  • The emergence of different and disparate materials together with the convergence of both the 'old' and 'emerging' technologies is paving the way for integration of heterogeneous technologies that are likely to extend the limitations of silicon technology beyond the roadmap envisaged for complementary metal-oxide semiconductor. Formulation of new information processing concepts based on novel aspects of nano-scale based materials is the catalyst for new nanoarchitectures driven by a different perspective in realization of novel logic devices. The memory technology has been the pace setter for silicon scaling and thus far has pave the way for new architectures. This paper provides an overview of the inevitability of heterogeneous integration of technologies that are in their infancy through initiatives of material physicists, computational chemists, and bioengineers and explores the options in the spectrum of novel non-volatile memory technologies considered as forerunner of new logic devices.