• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.74-77
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• 2002

In this paper we present a novel temperature compensated Hall effect power IC for accurate operation of wide temperature and high current drive of the motor coil. In order to compensate the temperature dependence of Hall sensitivity with negative temperature coefficient(TC), the differential amplifier has the gain consisted of epi-layer resistor with positive TC. The material of Hall device and epi-resistor is epi-layer with the same mobility. The variation of Hall sensitivity is -38% at 150$^{\circ}C$ and 88% at - 40$^{\circ}C$. But the operating point(B$\sub$op/) and release point(B$\sub$RP/) of the Hall power IC are within ${\pm}$25%. The experimental results show very stable and accurate performance over wide temperature range of -40$^{\circ}C$ to 125$^{\circ}C$.

• 센서학회지
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• 제19권1호
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• pp.31-35
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• 2010

High temperature micro pressure sensors were fabricated by using polycrystalline 3C-SiC piezoresistors grown on oxidized SOI substrates by APCVD. These have been made by bulk micromachining under $1{\times}1mm^2$ diaphragm and Si membrane thickness of $20{\mu}m$. The pressure sensitivity of implemented pressure sensors was 0.1 mV/$V{\cdot}bar$. The nonlinearity and the hysteresis of sensors were ${\pm}0.44%{\cdot}FS$ and $0.61%{\cdot}FS$. In the temperature range of $25^{\circ}C{\sim}400^{\circ}C$ with 5 bar FS, TCS (temperature coefficient of sensitivity), TCR (temperature coefficient of resistance), and TCGF (temperature coefficient of gauge factor) of the sensor were -1867 ppm/$^{\circ}C$, -792 ppm/$^{\circ}C$, and -1042 ppm/$^{\circ}C$, respectively.

• 센서학회지
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• 제13권3호
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• pp.175-181
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• 2004

A pressure sensor for high temperature was fabricated by using a SDB(Silicon-Direct-Bonding) wafer with a Si/$SiO_{2}$/ Si structure. High pressure sensitivity was shown from the sensor using a single crystal silicon of the first layer as a piezoresistive layer. It also was made feasible to use under the high temperature as of over $120^{\circ}C$, which is generally known as the critical temperature for the general silicon sensor, by isolating the piezoresistive layer dielectrically and thermally from the silicon substrate with a silicon dioxide layer of the second layer. The pressure sensor fabricated in this research showed very high sensitivity as of $183.6{\mu}V/V{\cdot}kPa$, and its characteristics also showed an excellent linearity with low hysteresis. This sensor was usable up to the high temperature range of $300^{\circ}C$.

• Journal of the Optical Society of Korea
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• 제7권2호
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• pp.84-88
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• 2003

A new method for temperature compensation of fiber Bragg grating (FBG) using hi-metal is proposed and experimentally demonstrated. Bi-metal bends toward the metal of low temperature expansion coefficient as the temperature increases, and this property is utilized to cancel the thermo-optic effect of the fiber. The optimum thickness of the high coefficient metal was empirically found by the trial-and-error method. The temperature sensitivities were 8.1 pm/$^{\circ}C$ and -0.018 pm/$^{\circ}C$ for the uncompensated and compensated FBGs, respectively, which indicates a reduction to a mere 0.22 % of the original sensitivity. No appreciable change in the spectral shape was observed. The packaging technique described in this paper is simple and compact, and it can be used for FBGs in WDM and DWDM communication systems that have stringent requirements on the temperature stability of the components.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.611-615
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• 1994

In this paper, the sensitivity, linearity and temperature drift characteristics of various capacitive force sensors are evaluated and compared using new experimental methods. In particular, two designs were employed to reduce temperature drift. Both types of sensor use high-sensitivity Al coated PET film, and their externals are miniaturized. The first has a layered design consisting of two dielectric substances with different temperature characteristics. The prototype of this design had a temperature drift of only 0.1% of the sensor's capacity in the 20-80.deg. C range. The second type uses both a dummy sensor ind an active sensor with the same characteristics. The temperature drift of the prototype was one-fifth the temperature drift of a single sensor.

• 조명전기설비학회논문지
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• 제22권4호
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• pp.1-12
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• 2008

이 연구의 목적은 백색 LED 조명의 광학적 특성 중에서 색온도 특성에 따른 사람들의 감성 반응을 평가하는데 있다. 이를 위해 백색 LED 모듈을 시제품으로 만들고, 감성 평가용 모형을 제작하여 색온도에 따른 감성 반응을 평가 분석하였다. 감성 평가에는 15개의 문항에 대하여 5단계 SD법으로 하였으며, 신뢰도 검증과 타당성 검증을 통하여 조명과 관련이 있는 3개의 요인을 선정하였다. 1요인을 활동성 요인으로 명명하였고, 2요인을 안정성 요인으로 명명하였으며, 3요인을 역량성 요인으로 명명하였다. 감성 평가를 분석하기 위해 종속 변수는 감성 평가 점수로 하였으며, 독립 변수는 색온도로 분석하였다. 이 연구에서 얻어진 결과를 정리하면 다음과 같다. 형광등과 비교한 백색 LED 조명에 있어서 색온도에 따른 사람들에 대한 감성 평가는 활동성 요인과 역량성 요인에서는 색온도가 8,300[K]인 $MA_3$ 조명을 높게 평가하였으며, 안정감 요인에서는 색온도가 3,800[K]인 $MA_1$ 조명을 높게 평가하였다.

• Smart Structures and Systems
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• 제19권3호
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• pp.269-277
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• 2017

Recently, there has been significant interest in structural health monitoring for civil engineering applications. In this research, a specially designed tendon, proposed by embedding FBG sensors into the center king cable of a 7-wire strand tendon, was applied for long-term health monitoring of tensile forces on a ground anchor. To make temperature independent sensors, the effective temperature compensation of FBG sensors must be considered. The temperature sensitivity coefficient ${\beta}^{\prime}$ of the FBG sensors embedded tendon was successfully determined to be $2.0{\times}10^{-5}^{\circ}C^{-1}$ through calibrated tests in both a model rock body and a laboratory heat chamber. Furthermore, the obtained result for ${\beta}^{\prime}$ was formally verified through the ground temperature measurement test, expectedly. As a result, the ground temperature measured by a thermometer showed good agreement compared to that measured by the proposed FBG sensor, which was calibrated considering to the temperature sensitivity coefficient ${\beta}^{\prime}$. Finally, four prototype ground anchors including two tension ground anchors and two compression ground anchors made by replacing a tendon with the proposed smart tendon were installed into an actual slope at the Yeosu site. Tensile forces, after temperature compensation was taken into account using the verified temperature sensitivity coefficient ${\beta}^{\prime}$ and ground temperature obtained from the Korean Meteorological Administration (KMA) have been monitored for over one year, and the results were very consistent to those measured from the load cell, interestingly.

• 한국지반환경공학회 논문집
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• 제4권3호
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• pp.69-77
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• 2003

대청호에서 WASP5 모델의 매개변수를 산정하고 민감도분석을 실시하였다. 모델의 계산치와 실측치는 값과 그 경향에 있어 근사한 것으로 나타나 이를 통해 대전취수탑 유역의 장래수질예측이 가능하였다. 매개변수의 민감도분석 결과 조류의 최대성장율, 조류의 호흡율, 광소멸계수, 온도 등이 Chlorophyll-a에 가장 큰 영향을 주는 것으로 나타났으며 T-N에 영향을 주는 주된 인자는 용존유기질소 분해율과 온도이며 T-P는 인부하량, 온도, 광소멸계수, 용존유기인 분해율, 조류의 최대성장율 등의 순으로 영향을 받는 것으로 나타났다. BOD에 큰 민감도를 보인 인자는 탈산소계수와 온도였으며, DO는 온도 외의 매개변수에 대한 영향은 거의 없는 것으로 나타났다. 모델의 민감도분석을 통하여 해당 수역에 적합한 입력변수의 민감도에 대한 평가를 하였으며 각 수질항목에 대한 입력변수의 영향에 대한 파악을 통해서 모델의 적용에 주의를 기해야할 해당 입력변수의 구분이 가능하였다.

• 센서학회지
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• 제17권4호
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• pp.303-307
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• 2008

$NiO,\;Cu_2O,\;Mn_2O_3$ and $Cr_2O_3$ as p-type semiconductors were added in CoO with 15 wt.% ethylene glycol binder and measured the butane gas sensing characteristics. The highest sensitivity is obtained for the NiO-CoO sensors. CoO-20 at.% NiO sensor with 15 wt.% ethylene glycol binder sintered at $1100^{\circ}C$ for 24 h exhibits high sensitivity of 90 % to 5000 ppm butane gas at the sensor temperature of $250^{\circ}C$, compared to low sensitivities at the low operating temperature for commercial sensors. Response and recovery times are, respectively, within few seconds and 1min in the static flow system, indicating rapid adsorption and desorption of butane gas on sensor surface even at this low temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.274-274
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• 2008

This paper describes on the fabrication and characteristics of a 3C-SiC (Silicon Carbide) micro pressure sensor for harsh environment applications. The implemented micro pressure sensor used 3C-SiC thin-films heteroepitaxially grown on SOI (Si-on-insulator) structures. This sensor takes advantages of the good mechanical properties of Si as diaphragms fabricated by D-RIE technology and temperature properties of 3C-SiC piezoresistors. The fabricated pressure sensors were tasted at temperature up to $250^{\circ}C$ and indicated a sensitivity of 0.46 mV/V*bar at room temperature and 0.28 mV/V*bar at $250^{\circ}C$. The fabricated 3C-SiC/SOI pressure sensor presents a high-sensitivity and excellent temperature stability.