• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.586-588
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• 2004

Although stable control algorithm has been implemented to the biped robot, the stability is not guaranteed because of encoder errors and/or rigid body elastics. Hence precise body pose estimation is required for more natural and long term walk. Specially pelvis sloping by gravity or uneven ground on landing place are most critical reason for undulated motion. In order to overcome these difficulties an estimation system for foot position and orientation using PSD sensors and Gyro sensors is proposed along with calibration algorithm and experimental verification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.107-110
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• 2003

In this paper, the optimal position selection of error sensors and transducers to attenuate interior noise from outside noise sources using active control techniques is presented. To get an optimal control characteristics in adaptive noise control systems, it is necessary to optimize the positions of sensors and transducers. A new type of simulated annealing method has been proposed as searching technique to find optimal transducers and sensors positions in which the sum of the squared pressures at sensor position in an enclosure can be best minimized. Computer simulations and experiments have been performed to show the effectiveness of the proposed method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.404-405
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• 2008

In this work, we investigated the effect of the functionalized SWNT-polymer composites for increasing sensitivity and imparting selectivity to nanotube sensors. To do this, CNT -based gas sensors were fabricated with two types of dispersed SWNT solution involving different polymer resin of TEOS (Tetraethyl orthosilicate) or MTMS (Methyl trimethoxysilane) which is blended to adhere to substrate well. As the surfaces of TEOS and MTMS surrounding SWNTs remain functionalized to -OH and $-CH_3$ groups respectively after hardening, gas adsorption will be affected differently according to the type of gases. In the experiment, we examined the response of electrical conductance for alcohol vapour gas. As the result, the conductance in the sensors using TEOS decreased considerably while that of MTMS was nearly invariable.

• 센서학회지
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• 제19권2호
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• pp.67-86
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• 2010

Hydrogen is emerging as clean fuel and important industrial raw materials. The hydrogen gas is not sensed by the human olfactory system, But the combustion characteristics of hydrogen is that the ignition is very easy, the propagation speed of the flame is very fast and explosion limits is a wide range of 4 %~75 %. Therefore it is extremely in danger, and the need for its leakage detection technologies is especially important in places such as a production, transportation, storage and usage. The hydrogen sensors are classified with ceramic type, semiconductor type, optical type, electrochemical type and so on. Hydrogen sensors and their technologies are reviewed in detail for materials, fabrication process, sensing characteristics, good point and faults, and production and utilization of sensors be discussed.

• 한국컴퓨터정보학회논문지
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• 제24권8호
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• pp.95-103
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• 2019

According to the Statistics Korea in 2017, the 10 leading causes of death contain a cardiac disorder disease, self-injury. In terms of these diseases, urgent assistance is highly required when people do not move for certain period of time. We propose an unusual event detection algorithm to identify abnormal user behaviors using dust, vision and activity sensors in their houses. Vision sensors can detect personalized activity behaviors within the CCTV range in the house in their lives. The pattern algorithm using the dust sensors classifies user movements or dust-generated daily behaviors in indoor areas. The accelerometer sensor in the smartphone is suitable to identify activity behaviors of the mobile users. We evaluated the proposed pattern algorithms and the fusion method in the scenarios.

• 센서학회지
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• 제4권4호
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• pp.47-54
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• 1995

센서의 계측에는 필연적으로 불화실성이 내포되어 있으며 이는 센서궤환장치의 신뢰성을 저하시키는 요인이 된다. 본 논문에서는 다중센서를 사용하여 신뢰성 높은 계측을 행하기 위한 기법을 연구하였다. 동적인 환경에서 작동하는 미지의 특성을 가진 센서들을 가정하였으며, 센서출력은 군집화와 추정된 신뢰도를 이용하여 융합하였다. 제안된 기법은 논리적으로 정의된 센서를 사용한 실험에서 기존의 확률적 기법들이 적용되기 어려운 상황에서도 피계측치에 대한 적응적 추정을 행할 수 있었다. 센서 로보트의 지능작업과 같이 구조화되어 있지 않은 환경에서 동작하는 자동화 장치를 위해 제안된 기법은 유용하게 사용될 수 있을 것이다.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.47-55
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• 2011

Reactor vessel internals comprehensive vibration assessment program(RVI CVAP) is one of the necessary tests to ensure the safety of nuclear power plants. RVI CVAP of U.S. nuclear regulatory commission regulatory guide 1.20(U.S. NRC R.G. 1.20) consists of the analysis, measurement and inspection. One of the core technologies of the measurement program for RVI CVAP is to select suitable sensors because the measurement is conducted during the critical path of the construction period of nuclear power plants. Therefore, we analyzed RVI thermal-hydraulic and structure design data of Palo Verde nuclear power plant(U.S.), Yonggwang nuclear power plant(Korea) and APR1400 and researched measuring sensors used in them; moreover, we investigated sensors used for measurement of RVI CVAP for the last 20 years throughout the world. Based on these results, we selected suitable measuring sensors for RVI CVAP in advanced power reactor 1400(APR1400).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.25-28
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• 2000

A capacitance-type humidity sensors in which porous silicon layer is used as humidity-sensing material was developed. This sensors was fabricated monolithically to be compatible with the typical IC process technology except for the formation of porous silicon layer. As the sensors is made as a mesa structure, the correct measurement of capacitance is expected because it can remove the effect of the parasitic capacitance from the bottom layer and another junctions. To do this, the sensor was fabricated using process steps such as localized formation of porous silicon, oxidation of porous silicon layer and etching of oxidized porous silicon layer. From completed sensors, capacitance response was measured on the relative humidity of 25 to 95% at room temperature. As the result the measured capacitance showed the increase over 300% at the low frequency of 120Hz, and showed little dependence on the temperature between 10 to $40^{\circ}C$.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.754-760
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• 2008

For monitoring of railway structures, optical fiber sensors are very convenient. The fiber sensors are very small and do not disturb the structural properties. They also have several merits such as electro-magnetic immunity, long signal transmission, good accuracy and multiplicity of one sensor line. Strain measurement technologies with fiber optic sensors have been investigated as a part of smart structure. In this paper, we investigated the possibilities of fiber optic sensor application to the monitoring of railway structures. We expect that the fiber optic sensors have much less noises than electrical strain gauges because of electro-magnetic immunity while railways operate electric power of 22000 volts. Fiber optic sensors showed good durability and long term stability for continuous monitoring of the railway structures as well as good response to the structural behaviors during construction.

• 센서학회지
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• 제18권2호
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• pp.179-183
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• 2009

Toluene($C_6H_5CH_3$) gas sensors were fabricated using $PtO_x$ loaded with SWNTs by a new deposition method. The nanoparticle powders of SWNTs-$PtO_x$ composite were deposited on Si wafer substrates by a vacuum filtering deposition method. The fabricated sensors were tested against toluene gas which is a kind of the Volatile Organic Compounds. The composition ratio that exhibited the highest response to toluene gases was SWNTs : $PtO_x\;=\;99:1$ in wt% ratio at operating temperature of about $150^{\circ}C$. The response and recovery times of the sensors were as short as less than 1 min., respectively.