• 센서학회지
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• 제17권3호
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• pp.157-161
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• 2008

An optical sensor was developed to detect nanoparticles, turbid materials and microorganisms in water simultaneously. Three different light sources like UV-LED, NIR-LED and laser diode have been employed to develop the optical sensor based on the scattering light and fluorescence light. The sensor system has high selectivity and sensitivity, that it can be used to monitor the quality of drinking water.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.294-298
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• 2004

Carbon nanotubes(CNTs) were synthesized by thermal chemical vapor deposition(CVD) method. To fabricate CNT gas sensor, catalyst metal layer was deposited on microstructure. The CNT gas detecting layer was grown by thermal CVD method on the catalyst metal layer. In order to investigate the gas sensing characteristics of the fabricated CNT gas sensor, it was exposed in NO$_2$ gas and sensitivity, response, and recovery time were measured. As the result, this sensor has better reproductibility and faster recovery time than another CNT gas sensors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.589-594
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• 1993

This paper presents a fault detection strategy that discriminates the faulty sensor and that detects the component fault using a bank of observers for the system in which sensor fault and component fault can occur simultaneously. Observers as many as the number of measurements are designed, and each observer uses measurements excluding sequentially one measurement, to estimate the state variables. The faulty sensor can be found out by comparing each state variable from different observer. Next, component fault can be detected by using measurements from the sensors excluding the faulty sensor. The suggested strategy is applied to a nonisothermal, series reaction with unknown reaction kinetics in a CSTR. This strategy is found out to perform well even in the case that the sensor and component fault occur simultaneously. Since each observer is designed to be independent of reaction kinetics, this strategy is not affected by the model uncertainty and nonlinearity of the reaction kinetics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.99-101
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• 2006

Auto-Cross Correlated time series (ACTS) model was constructed by using the backpropagation neural network. The performance of ACTS model was evaluated with sensor information collected from a large volume, industrial plasma-enhanced chemical vapor deposition system. A total of 18 sensor information were collected. The effect of inclusion of past and future information were examined. For all but three sensor information with a large data variance demonstrated a prediction error less than 3%. By integrating ACTS model into equipment software, process quality can be more stringently monitored while improving device throughput.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.102-104
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• 2006

Auto-Correlated time series (ATS) model was constructed by using the backpropagation neural network. The performance of ATS model was evaluated with sensor information collected from a large volume, industrial plasma-enhanced chemical vapor deposition system. A total of 18 sensor information were collected. The effect of inclusion of past and future information were examined. For all but three sensor information with a large data variance demonstrated a prediction error less than 4%. By integrating ATS model into equipment software, process quality can be more stringently monitored while improving device throughput.

• 대한전자공학회논문지
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• 제27권4호
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• pp.563-570
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• 1990

A silicon pressure sensor made of a full bridge of diffused resistors was designed and fabricated using semiconductor integrated circuit process. Thin diaphragms with 30\ulcorner thickness were obtained using anisotropic wet chemical etching technique. Our device showed strong temperature dependence. Compensation networks are used to compensate for the temperature dependence of the pressure sensor. The bridge supply voltage having positive temperature coefficient by compensation networks was utilized against the negative temperature coefficient of bridge output voltage. The sensitivity fluctuation of pressure sensor before temperature compensation was -1700 ppm/\ulcorner, while it reduced to -710ppm\ulcorner with temperature compensation. Our result shows that the we could develop accurate and reliable pressure sensor over a wide temperature range(-20\ulcorner~50\ulcorner).

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권2호
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• pp.128-132
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• 2004

This paper presents the design, fabrication sequence and measurement results of a highly sensitive capacitive-type humidity sensor using a polyimide film without hydrophobic elements. The structure of the humidity sensor is MIM (metalinsulator-metal). For a high sensitivity, a modified aromatic polyimides as a moisture absorbing layer has been synthesized instead of using general polyimides containing hydrophobic elements. The polyimide film was obtained by synthesizing and thermally polymerizing polyamic acid composed of m-pyromellitic dianhydride, phenelenediamine and dimethylacetamide. Characteristics of fabricated sensors which include sensitivity, hysteresis and stability have been measured. The measurement result shows the percent normalized capacitance change of 0.37/%RH over a range from 10 to 90%RH, hysteresis of 0.77% over the same %RH range and maximum drift of 0.25% at 50%RH. The result shows that the developed humidity sensor can be applied to evaluate a hermeticity of various sensors and actuator systems as well as micro packages.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1815-1817
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• 2007

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.699-700
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• 2003

• Bulletin of the Korean Chemical Society
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• 제28권7호
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• pp.1221-1223
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• 2007