• 전자공학회논문지A
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• 제33A권4호
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• pp.136-141
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• 1996

In this paper, a new CMOS on-chip current reference circit for memory, operational amplifiers, comparators, and data converters is proposed. The reference current is almost independent of temeprature and power-supply variations. In the proposed circuit, the current component with a positive temeprature coefficient cancels that with a negative temperature coefficient each other. While conventional curretn and voltage reference circuits require BiCMOS or bipolar process, the presented circuit can be integrated on a single chip with other digiral and analog circits using a standard CMOS process and an extra mask is not needed. The prototype is fabricated employing th esamsung 1.0um p-well double-poly double-metal CMOS process and the chip area is 300um${\times}$135 um. The proposed reference current circuit shows the temperature coefficient of 380 ppm/.deg. C with the temperature changes form 30$^{\circ}C$ to 80$^{\circ}C$, and the output variation of $\pm$ 1.4% with the supply voltage changes from 4.5 V to 5.5 V.

• 한국전기전자재료학회논문지
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• 제11권7호
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• pp.546-551
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• 1998

$Mn{1-X}Fe{2+X}O_4, Mg_{1-X}Fe_{2+X}O_4$ (x=0.0, 0.025, 0.1, 0.2) for negative temperature coefficient (NTC) thermistor was prepared by calcination at $800^{\circ}C$ and sintering at form 1100 to $1250^{\circ}C$ with $50^{\circ}C$ intervals. The best linear property was obtained in the Mn-based sample sintered at $1200^{\circ}C$ with x=0.0 composition. Temperature coefficient of resistance, $\alpha$, was $-5.6%/^{\circ}C$ in the Mn-based sample, $-5.2%/^{\circ}C$ in the MM-based sample, and $-1.6%/^{\circ}C$ in the Mg-based sample. thermistor parameter, B, was in the range of 2665~7780 K. The results show the possibility that Mn-Ni-Co based thermistor could be substituted by the composition used in this study.

• 대한전기학회논문지
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• 제45권1호
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• pp.81-85
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• 1996

Microwave dielectric properties of 0.15(B $a_{x}$S $r_{0.05}$)O-0.15(S $m_{2}$(1-y)N $d_{2y}$) $O_{3}$-0.7Ti $o_{2}$(x=o.9~0.1[mol.], y=6[m/o]) ceramics were investigated with BaO compositional ratio. Sintered density and resistivity of specimens were independent on the BaO compositional ratio. In the specimen with x=0.975[mol.], dielectric constant, quality factor and temperature coefficient of resonant frequency had good values of 76.52, 3001(at 3[GHz]) and +0.71[ppm/.ceg. C], respectively. By comparing with the stoichiometric compositions of 78.14, 2938(at 3[GHz])+14.19[ppm/.ceg. C], dielectric constant and quality factor showed similar properties, but the temperature coefficient of resonant frequency was highly improved. (author). refs., figs., tabs.s.s.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.300-303
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• 2001

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristic temperature dependence : almost a constant value of 0.49 below 730$^{\circ}C$ and decreases linearly with temperature over 730$^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, Bi$_2$O$_3$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi 2212 phase formation in the co-deposition process.

• 전기학회논문지
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• 제62권2호
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• pp.284-287
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• 2013

In this work, we have fabricated TiC films by using unbalanced magnetron sputtering method with graphite and Ti targets for contact strip application of electric railway. TiC films were deposited with various substrate temperatures. We investigated various properties of TiC films prepared with various substrate temperatures, such as the hardness, surface roughness, friction coefficient, resistivity, FESEM (Field Emission Scanning Electron Microscopy), HRTEM (High Resolution Transmission Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy). The hardness and friction coefficient properties of TiC films were improved with increasing substrate temperature. These results indicate that the improvement of hardness and resistivity is related to the increase of sp2 clusters in TiC films. And also, the resistivity value of TiC films were decreased with increasing substrate temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.213-216
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• 1999

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristics temperature dependence : almost a constant value of 0.49 below 730$^{\circ}C$ and decreases linearly with temperature over 730$^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, Bi$_2$O$_3$ from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi(2212) phase formation in the co-deposition process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.193-197
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• 2000

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristic temperature dependence : almost a constant value of 0.49 below 73$0^{\circ}C$ and decreases linearly with temperature over 73$0^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, Bi$_2$O$_3$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi(2212) phase formation in the co-deposition process.

• Applied Microscopy
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• 제47권3호
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• pp.121-125
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• 2017

This study deals the prediction of temperature effect on low-frequency dispersion of alternating current (AC) conductivity spectra of composite materials based on copolymer reinforced with carbon black (CB) particles. A sample of ethylene butylacrylate loaded with 13% of CB particles were prepared and investigated using the impedance spectroscopy representation in the frequency range from 40 Hz to 0.1 MHz and temperature range from $20^{\circ}C$ to $125^{\circ}C$. The dielectric constant, ${\varepsilon}^{\prime}$, and dielectric losses, ${\varepsilon}^{{\prime}{\prime}}$, were found to decrease with increasing frequency. The frequency dependence of the AC conductivity follows the universal power law with a large deviation in the high frequency region, the positive temperature coefficient in resistivity effect has been observed below the melting temperature which makes this composite potentially remarkable for industrial applications.

• 한국산업정보학회논문지
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• 제12권2호
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• pp.79-84
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• 2007

본 논문에서는 CMOS를 이용한 온도 제어회로를 MOSIS의 0.25um-3.3V CMOS 설계규칙에 따라 설계하고 SPICE 시뮬레이션과 실험을 통하여 성능을 검토하였다. 설계된 회로는 $0^{\circ}C{\sim}150^{\circ}C$의 온도 범위에 대하여 출력 전압이 약 $13mV/^{\circ}C$로 변화하며 좋은 온도 선형성을 나타내었다. 또한, 바이어스 전압을 변화시키면 온도변화에 대한 출력전압의 변화량을 조정할 수 있다. 제안된 회로는 온 칩 수정발진회로의 설계 등에 유용하게 사용될 수 있을 것으로 기대된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.391-396
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• 2001

In order to estimate thermal cracking in mass concrete and to decide the removal time of the forms outside the concrete structures in wintertime, temperature measurement is indispensible. Until now, the measurement system employs thermocouple type. In this paper, we introduce economical and accurate NTC(Negative Temperature Coefficient) ceramic type measurement system. In principle, NTC ceramic type sensor is very sensitive in the range -20~15$0^{\circ}C$. In this range, the signal change is so large that the sensor needs less amplification than thermocouple. Therefore, not only the sensor itself is inexpensive but also the system is too. In this experiments the temperature of the NTC system are identical to those of thermocouple. In conclusion, inexpensive NTC thermistor system is very adequate to the temperature measurement during concrete curing.