• Title/Summary/Keyword: Reference temperature

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CMOS Reference Voltage Generator (CMOS 기준 전압 발생기)

  • Choi, Yong;Kim, Myung-Sik
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.655-658
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    • 1998
  • CMOS Reference Voltage Generator(RVG) is designed to possible CMOS process without additional process steps. It is possible to compensate the temperature of RVG by using PTAT(proportional to the absolute temperature). Temperature compensation is profitable because $\mun$ (electron mobility) is used. When VDD sweeps from 3V to 7V, variation ratio of Vref is 0.3125mV/V. Also temperature variation ratio of Vref is $047.1ppm/^{\circ}C$ during sweeping from $0^{\circ}C$ to $100^{\circ}C.$ Power Consumption is $50.3\muW.$

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Temperature Preconditioning for Improving Convergence Characteristics in Calculating Low Mach Number Flows, II: Navier-Stokes Equations (저속 유동 계산의 수렴성 개선을 위한 온도예조건화 II: 나비어스톡스 방정식)

  • Lee, Sang-Hyeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.12
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    • pp.1075-1081
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    • 2007
  • The temperature preconditioning is applied to the Navier-Stokes equations. Also, a new concept of diffusion Mach numbers is introduced to modify the reference Mach number for the Navier-Stokes equations. Flows over a circular cylinder were calculated at different Reynolds numbers. It is shown that the temperature preconditioning improves the convergence characteristics of Navier-Stokes equations. Also, it is shown that the modified reference Mach number alleviates the convergence problems at locally low speed regions.

An Experimental Study on a Simultaneous Determination of Reference Free-Stream Temperature and Convective Heat Transfer Coefficients (자유흐름온도와 대류열전달계수를 동시에 측정할 수 있는 방법에 대한 실험적 연구)

  • 송기범;정기호;성영식;김귀순
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.10
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    • pp.1465-1471
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    • 2002
  • This paper deals with the development of a new method that can obtain the heat transfer coefficient and the reference free stream temperature simultaneously. The method is experimentally verified through comparison with results in convective heat transfer experiments of a circular impinging jet using two narrow-band TLCs. The general method described in this paper is highly recommended to many heat transfer models with the unknown or ambiguous free stream temperature.

Simultaneous Determination of Reference Free-Stream Temperature and Convective Heat Transfer Coefficients (자유흐름 온도와 대류열전달 계수를 동시에 측정할 수 있는 실험 방법에 대한 연구)

  • Jeong, Gi-Ho;Song, Ki-Bum;Kim, Kui-Soon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.12
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    • pp.1707-1714
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    • 2002
  • This paper deals with the development of a new method that can obtain heat transfer coefficient and reference free stream temperature simultaneously, The method is based on transient heat transfer experiments using two narrow-band TLCs. The method is validated through error analysis in terms of the random uncertainties in the measured temperatures. It is found that the errors could be reduced more than 2 times less. The general method described in this paper is applicable to many heat transfer models with unknown free stream temperature.

Diagnostic Technique for Mold Transformer Windings using Thermal Image (열화상을 이용한 몰드변압기 권선표면 진단)

  • Lim, Y.B.;Jung, J.W.;Jung, J.S.;Ko, W.S.
    • Proceedings of the KIEE Conference
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    • 2005.11c
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    • pp.107-109
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    • 2005
  • Temperature distribution measured to estimate condition of an electrical apparatus is an absolute reference for the apparatus conditions and the difference between the reference temperature and the current one. Because a passive thermography without the external thermal stimulation shows the difference in surface temperature between the object and back ground, the results can apply only to the estimation or the monitoring for the condition of terminal loose and the overload pertaining to the rise in temperature. However, a thermal flow in the active thermography is differently generated by the structure and condition of the surface and subsurface. This paper presents the nondestructive testing using the behavior and deals with the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

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Aging Analysis of Catenary Wires in Accordance with Temperature Changes for a Long Period of Time (장기간 온도변화에 따른 전차선로 전선류의 노후도 분석)

  • Cho, Nam-Hee;Oh, Wan-Shik;Kim, Jae-moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.9
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    • pp.1590-1596
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    • 2016
  • In this paper, catenary wires were analyzed aging through the experiment about a new product and a test sample in accordance with temperature changes from long-term use. In case of the contact wire, the maximum load was reduced within 7% and the tensile strength showed a reduced within 6.7% compared with a new reference standard $110mm^2$. 19 Strands of messenger wire have a little more than a standard value, but result data on tensile test were less than the reference value about stranded wire. Also parts among 49 strands of dropper was found to be smaller than the reference value and it appeared greatly increasing intensity as toward the center of the strand.

Detection and Property of Leptospiral Hemolysin (렙토스피라용혈소의 검색과 성질)

  • Chang, Woo-Hyun;Kang, Jae-Seung
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.1
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    • pp.23-33
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    • 1987
  • To detect lepotospiral strains which produce hemolysin and determine the optimal condition for assaying hemolysin, we screened reference strains and observed some property of hemolysin. Hemolysin activity was assayed with cell free culture liquids and erythrocyte suspension. The production of hemolysin by local strains isolated in Korea was assayed and compared with that of reference strains. The hemolysin was produced by 18 strains among 38 reference strains and 3 local strains isolated in Korea. The production of hemolysin began with growth of Leptospira cultured in EMJH medium and reached maximum at stationary phase. The optimum temperature for hemolytic activity was $37^{\circ}C$. At lower temperature the activity of hemolysin was decreased progressively. The hemolytic activity was completely inactivated after :30 minutes' exposure at $56^{\circ}C$. Hemolysis pattern was "hot-cold type" which showed increased hemolysis after cold incubation. The hemolysin was most active on sheep erythrocyte and less active on ox, goat, human and guinea pig erythrocyte with the decreasing order.

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A Study of On-Chip Voltage Down Converter for Semiconductor Devices

  • Seo, Hae-Jun;Kim, Young-Woon;Cho, Tae-Won
    • Journal of IKEEE
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    • v.12 no.1
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    • pp.34-42
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    • 2008
  • This paper proposes a new on-chip voltage down converter(VDC), which employs a new reference voltage generator(RVG). The converter adopts a temperature-independence reference voltage generator, and a voltage-up converter. The architecture of the proposed VDC has a high-precision, and it was verified based on a 0.25${\mu}m$ 1P5M standard CMOS technology. For 2.5V to 1.0V conversion, the RVG circuit has a good characteristics such as temperature dependency of only 0.2mV/$^{\circ}C$, and the voltage-up circuit has a good voltage deviation within ${\pm}$0.12% for ${\pm}$5% variation of supply voltage VDD. The output voltage is stabilized with ${\pm}$1mV for load current varying from 0 to 100mA.

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Modeling of Daily Reference Evapotranspiration using Polynomial Networks Approach (PNA) (PNA를 이용한 일 기준증발산량의 모형화)

  • Kim, Seong-Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.473-473
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    • 2011
  • Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily reference evapotranspiration (ETo) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it consists of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily ETo data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as ETo modeling can be generalized using GMDH-NNM.

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