• 한국구조물진단유지관리공학회 논문집
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• 제7권3호
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• pp.133-138
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• 2003

FBG sensor의 다중 측정성을 이용하여 모르타르 시편의 열 변형률과 온도 변화를 동시에 측정하였다. 또한, 광섬유 격자 센서를 이용하여, 열 변화에 따른 모르타르 시편의 내부 온도 구배를 측정하였다. 열 변형률을 기존 strain gauge와 함께 측정하였을 때, strain gauge는 섭씨 60도 이상의 온도에서 오차를 보이는 반면, FBG 센서는 안정된 측정값을 나타냈다. FBG 온도 sensor로 측정한 온도 변화량은 thermocouple로 측정한 값과 비교하였으며, 선형적인 대응관계를 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.1029-1032
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• 2002

This paper describes a design of a tactile sensor, which can measure three components force and temperature due to thermal conductive. The bio-mimetic tactile sensor, alternative to human's finger, is comprised of four micro force sensors and four thermal sensors, and its size being 10mm$\times$10mm. Each micro force sensor has a square membrane, and its force range is 0.1N - 5N in the three-axis directions. On the other hand, the thermal sensor for temperature measurement has a heater and four temperature sensor elements. The thermal sensor is designed to keep the temperature. $36.5^{\circ}C$, constant, like human skin, and measure the temperature $0^{\circ}C$ to $50^{\circ}C$. The MEMS technology is applied to fabricate the sensing element of the tactile sensor.

• 동력기계공학회지
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• 제10권4호
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• pp.43-49
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• 2006

Nowadays, the thermal environments of classrooms are usually adjusted by the ceiling type air-conditioning system with a temperature sensor installed on inlet of an air-conditioner. However, it is not clear that the conventional temperature sensor position is proper to satisfy both thermal comport and energy saving in summer especially. Therefore, this study is aimed at finding out the best position of the temperature sensor on the purpose of the comfort thermal environment and energy saving. The different 5 positions for the temperature sensor are supposed in this paper to analyze thermal environment by CFD. From the analysis through the CFD simulations, the best position of the temperature sensor satisfying for both comfort thermal environment and energy saving is obtained.

• 제어로봇시스템학회논문지
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• 제6권5호
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• pp.396-403
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• 2000

A thermal imaging system is implemented for the measurement and the analysis of the thermal distribution of the target objects. The main part of the system is a thermal camera in which a focal plane array typed sensor is introduced. The sensor detects the mid-range infrared spectrum of target objects and then it outputs a generic video signal which should be processed to form a frame thermal image. Here, a digital signal processor(DSP) is applied for the high speed processing of the sensor signals. The DSP controls analog-to-digital converter, performs correction algorithms and outputs the frame thermal data to frame buffers. With the frame buffers can be generated a NTSC signal and transferred the frame data to personal computer(PC) for the analysis and a monitoring of the thermal scenes. By performing the signal processing functions in the DSP the overall system achieves a simple configuration. Several experimental results indicate the performance of the overall system.

• 센서학회지
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• 제27권5호
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• pp.300-305
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• 2018

The uncooled microbolometer thermal sensor for low cost and mass volume was designed to target the new infrared market that includes smart device, automotive, energy management, and so on. The microbolometer sensor features 80x60 pixels low-resolution format and enables the use of wafer-level vacuum packaging (WLVP) technology. Read-out IC (ROIC) implements infrared signal detection and offset correction for fixed pattern noise (FPN) using an internal digital to analog convertor (DAC) value control function. A reliable WLVP thermal sensor was obtained with the design of lid wafer, the formation of Au80%wtSn20% eutectic solder, outgassing control and wafer to wafer bonding condition. The measurement of thermal conductance enables us to inspect the internal atmosphere condition of WLVP microbolometer sensor. The difference between the measurement value and design one is $3.6{\times}10-9$ [W/K] which indicates that thermal loss is mainly on account of floating legs. The mean time to failure (MTTF) of a WLVP thermal sensor is estimated to be about 10.2 years with a confidence level of 95 %. Reliability tests such as high temperature/low temperature, bump, vibration, etc. were also conducted. Devices were found to work properly after accelerated stress tests. A thermal camera with visible camera was developed. The thermal camera is available for non-contact temperature measurement providing an image that merged the thermal image and the visible image.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.184-189
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• 2000

Two types of fiber-optic sensors, EFPI(extrinsic Fabry-Perot interferometer) and FBG(fiber Bragg grating), have been investigated for measurement of thermal strain and temperature. The EFPI sensor is only for measurement of thermal strain and the FBG sensor is for simultaneous measurement of thermal strain and temperature. FBG temperature sensor was developed to measure strain-independent temperature. This sensor configuration consists of a single-fiber Bragg grating and capillary tube which makes it isolated from external strain. This sensor can then be used to compensate for the temperature cross sensitivity of a FBG strain sensor. These sensors are demonstrated by embedding them into a graphite/epoxy composite plate and by attaching them on aluminum rod and unsymmetric graphitelepoxy composite plate. All the tests were conducted in a thermal chamber with the temperature range $20-100^{\circ}C$. Results of strain measurements by fiber-optic sensors are compared with that from conventional resistive foil gauge attached on the surface.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.345-350
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• 1999

The effectiveness of software error compensation for thermally induced machine tool errors relies on the prediction accuracy of the pre-established thermal error models. The selection of optimal sensor locations is the most important in establishing these empirical models. In this paper, a methodology for the selection of optimal sensor locations is proposed to establish a robust linear model which is not subjected to collinearity. Correlation coefficient and time delay are used as thermal parameters for optimal sensor location. Firstly, thermal deformation and temperatures are measured with machine tools being excited by sinusoidal heat input. And then, after correlation coefficient and time delays are calculated from the measured data, the optimal sensor location is selected through hard c-means clustering and sequential selection method. The validity of the proposed methodology is verified through the estimation of thermal expansion along Z-axis by spindle rotation.

• 한국전기전자재료학회논문지
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• 제28권6호
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• pp.403-407
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• 2015

Generally, MWCNT, with thermal, chemical and electrical superiority, is manufactured with CVD (chemical vapor deposition). Using MWCNT, it is comonly used as gas sensor of MOS-FET structure. In this study, in order to repeatedly detect gases, the author had to effectively eliminate gases absorbed in a MWCNT sensor. So as to eliminate gases absorbed in a MWCNT sensor, the sensor was applied heat of 423[K], and in order to observe how the applied heat was diffused within the sensor, the author interpreted the diffusion process of heat, using COMSOL interpretation program. In order to interpret the diffusion process of heat, the author progressed modeling with the structure of MWCNT gas sensor in 2-dimension, and defining heat transfer velocity($u={\Delta}T/{\Delta}x$), accorded to governing equation within the sensor, the author proposed heat transfer mechanism.

• 설비공학논문집
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• 제15권10호
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• pp.870-878
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• 2003

The maintenance of thermal equilibrium between the human body and its environment is one of the primary requirements for health, wellbeing and comfort. For the effective control of indoor thermal environment, thermostat or humidistat is used. But, it is not sufficient to control the indoor thermal environment using only one or two parameters as human response for the indoor comfortable environment. So an environmental thermal index is required for the control of indoor thermal environment effectively. In this study, a PMV sensor has been developed which has integrated from various kinds of individual sensors for temperature, humidity, air velocity, radiant temperature. After applying the PMV and PPD equation, it is possible to monitor the indoor thermal environment with the sensor system, which is adopted to the circuit for optimization according to the human response with the metabolic rate and activities. The measurement was carried out to verify the performance of the integrated sensor system in comparison with existing measurement system, the PMV meter. As a result, the possibility of applying the PMV sensor to control the indoor thermal environment simultaneously was examined.

• 한국전기전자재료학회논문지
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• 제33권4호
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• pp.321-325
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• 2020

Atmospheric environmental problems have a major impact on human health and lifestyle. In humans, inhalation of nitrogen oxides causes respiratory diseases, such as bronchitis. In this paper, thermal analysis of a gas sensor was carried out to design and fabricate a wearable nylon-yarn gas sensor for the detection of NO_x gas. In the thermal analysis method, the thermal diffusion process was analyzed while operating the sensors at 40 and 60℃ to secure a temperature range that does not cause thermal runaway due to temperature in the operating environment. Thermal diffusion analysis was performed using the COMSOL software. The thermal analysis results could be useful for analyzing gas adsorption and desorption, as well as the design of gas sensors. The thermal energy diffusion rate increased slightly from 10.05 to 10.1 K/mm as the sensor temperature increased from 40 to 60℃. It was concluded that the sensor could be operated in this temperature range without thermal breakdown.