• Title/Summary/Keyword: characteristic resistance

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Negative Resistance cCaracteristic in Gate Circuit of SCR (SCR의 Gate 회로에서의 부성저항특성)

  • Byung Chuel Bark
    • 전기의세계
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    • v.23 no.6
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    • pp.56-59
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    • 1974
  • It is well-known that the anode circuit of SCR has the current controlled negative resistance characteristic. Recently the present auther has shown that the gate circuit of SCR has the voltage controlled negative resistance characteristic for the constant anode voltage. It is shown of the equivalent model to SCR(when conducting) the voltage controlled negative resistance characteristic for gate circuit. And it is possible to make SCR gate oscillators with their desired characteristic for illustration.

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Study on the characteristic of high precision thin film resistor

  • Park Hyun Sik;Yu Yun Seop
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.628-635
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    • 2004
  • The characteristic of thin film resistor with low TCR( temperature coefficient of resistance ) and high precision are studied. The thin film resistor for 1/4W was fabricated and characteristic of these resistors was investigated. The fabricated device had the thickness of $2.48{\leqq}$ and the resistivity of $0.27{\omega}mm$. The electrical characteristic was evaluated by HP 4339B and 4284A instruments with HP l6339A. The profile of trimmed structure was also measured by non contact interferometer. The change of resistance and TCR increased with increasing roughness and resistance. To reduce the effect of stress annealing treatment was performed in the range of 563 to 623 K after trimming. The characteristic was improved after annealing. It is expected the fabricated device can be useful for high precision and low TCR. Fabricated thin film resistor has average deviation of resistance less than $0.35{\%}$ and TCR within 60.60ppm/K.

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Determination of Design Parameters from Ground Investigation Results -Focus on geotechnical characteristic values- (지반조사결과에서 설계변수의 결정문제 -지반특성치 산정을 중심으로-)

  • Yoon, Gil-Lim;Yoon, Yeo-Won;Kim, Hong-Yeon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.126-133
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    • 2008
  • Geotechnical limit state design methods; LRFD of North America is an approach that estimates resistance using design model and then multiplies resistance factor by calculated resistance to reflect the uncertainty of geomaterials and design models; whereas, Eurocode of the Europe employs the partial resistance factor applied directly to each variable in the resistance equation that individual soil properties such as cohesion and angle of internal friction are applied. This discussion paper is a study on characteristic value which has globally been argued through processing of development of Eurocode 7 for geotechnical design even to the present. Estimating the characteristic value of soil properties affects not only determination of design value applied directly to design of geotechnical structures, but also economic feasibility and stability of the structures.

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A Study on the operational characteristics of Thermal.Current Resistance of 3 phase HTS Cable under Unbalanced load operation (3상 초전도케이블의 불평형 부하운전시 열.전류 저항에 의한 운전특성연구)

  • Lee, Geun-Joon;Hwang, Si-Dole;Lee, Hyun-Chul
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.189-1-190-1
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    • 2008
  • A high temperature superconducting(HTS) power cable is available for high capacity current in normal condition. But resistance was appeared to operate unbalance load by thermal current characteristic. This characteristic of HTS power cable used to design for unstated condition. And than, It used to understand and analyze characteristic of power cable thermal and critical current. This study appeared that quench resistance reason from shield and former current rise to superconductor(SC) current. The resistance of SC occurred that the cable temperature rise to fault current after decreased critical current. The quench resistance of SC increased in temperature or decreased in critical current. So the quench resistance of SC correlated with resistance of both shield and former current. It need to sufficiently influenced the parameters of HTS cable design.

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A study on a modeling method about current-voltage characteristic of HTS tape considering resistance of stabilizer

  • Lee, W.S.;Lee, J.;Nam, S.;Ko, T.K.
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.3
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    • pp.9-12
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    • 2013
  • Current-voltage characteristic models of superconducting material are suggested by many researchers. These current-voltage characteristic models are important because they can be used for design or simulation of superconductor devices. But widely used current-voltage models of superconductor wire still have some limitations. For example, a standard E-J power model has no parameters related with stabilizer's resistance in superconductor wire. In this paper, a current-voltage characteristic modeling method for high temperature superconductor (HTS) tape with considering the effect of stabilizer is introduced. And a current-voltage characteristic of a HTS tape is measured under different stabilizer conditions. Those measured current-voltage characteristics of the HTS tape modeled with proposed modeling method and the modeling results are compared.

A study on influence of flame retardant on tracking resistance (난연성이 내트래킹 특성에 미치는 영향에 관한 연구)

  • Jung, Se-Young;Kim, Byung-Kyu;Yeo, Hak-Gue;Kang, Doo-Whan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.493-496
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    • 2003
  • Electrical characteristic of tracking resistance, volume resistance, insulation breaking strength etc. and mechanical characteristic are required to high voltage insulation insulator silicone rubber. Tracking resistance is adding much ATH to improve tracking resistance as the most important factor among them. But, there is problem that mechanical strength grows worse rapidly adding much ATH. Therefore, this research studied effect that flame retardant gets to tracking resistance during factor that influence to tracking resistance.

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Analysis of a Geometrically Asymmetric Trapezoidal Fin with Variable Fin Base Thickness and Height

  • Kang, Hyung-Suk
    • International Journal of Air-Conditioning and Refrigeration
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    • v.16 no.3
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    • pp.83-88
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    • 2008
  • A geometrically asymmetric trapezoidal fin is analyzed using the one-dimensional analytic method. Heat loss and thermal resistance are represented as a function of the fin base thickness, base height, fm shape factor, inside fluid convection characteristic number, convection characteristic numbers ratio, fm length and ambient convection characteristic number. The relationship between the fin base height and the shape factor for equal amounts of heat loss is presented. One of the results shows that the variations of the fm base thickness and the inside fluid convection characteristic number give no effect on the thermal resistance.

Analysis of a Pin Fin with Variable Fin Base Thickness (핀 바닥두께가 변하는 pin 핀의 해석)

  • Kang, Hyung-Suk
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.642-645
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    • 2008
  • A pin fin with variable fin base thickness is analysed by using the one dimensional analytic method. Heat loss and fin thermal resistance are presented as a function of the fin base thickness, pin fin outer radius and convection characteristic numbers ratio. The relationship between the fin outer radius and fin base thickness for the same amount of heat loss is shown. One of the results indicates the fin thermal resistance decreases as the fin outer radius and/or convection characteristic numbers ratio increase whereas the fin thermal resistance is independent on the variation of fin base thickness.

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Characteristic on the Resistance of Chloride Infiltration in Concrete Containing Limestone Powder (석회석 미분말 혼합 콘크리트의 염소이온 침투 저항 특성)

  • 구봉근;라재웅;류택은;이재범;이현석;이기호
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.75-80
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    • 2002
  • This study is to investigate the characteristic on the resistance of chloride infiltration concrete containing limestone powder The variables are the substitution ratio of slag powder and limestone powder. In order to study the effect slag powder and limestone powder, all mixtures were prepared at a fixed water/cement ratio, slump, and entrained air quantity. As results show that the strength and the resistance of chloride infiltration in concrete substitution 10%, 20% limestone powder, and 30%, 40% slag powder are positive.

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Electrical characteristic of Phase-change Random Access Memory with improved bottom electrode structure (하부전극 구조 개선에 의한 상변화 메모리의 전기적 특성)

  • Kim, Hyun-Koo;Choi, Hyuk;Cho, Won-Ju;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.69-70
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    • 2006
  • A detailed Investigation of cell structure and electrical characteristic in chalcogenide-based phase-change random access memory(PRAM) devices is presented. We used compound of Ge-Sb-Te material for phase-change cell. A novel bottom electrode structure and manufacture are described. We used heat radiator structure for improved reset characteristic. A resistance change measurement is performed on the test chip. From the resistance change, we could observe faster reset characteristic.

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