• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.436-438
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• 2007

As the sensors and communication technology get advance, the remote health diagnosis for patients and senior persons at home are possible now without visiting doctors in hospitals. A low-power ubiquitous health check device was developed adapting Real-Time Embedded Linux is developed. This ubiquitous device is consisted of three sensors. The wrist type health checking terminal acquires periodically the health data by using a blood pressure sensor, a pulse sensor and a body temperature sensor. It transmits the health data to the access point located at the home center through the ZigBee wireless communication modem. This health data collector or access point device sends the data again to the main server operated in a hospital or health care organization. The health server control continuously the input data and sends an alarm signal to the assigned. doctor and responsible persons using cellular SMS when any dangerous events occur. This wrist type health check device has an embedded linux OS using Intel PAX255 MPU. The developed U-Health system is applicable for checking patients health in remote at home. And their family or related persons in remote site can check the patients health status at any time. They can be assured by receiving SMS record and alarm of emergency case which is transmitted from the health server.

• 대한임베디드공학회논문지
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• 제11권1호
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• pp.15-20
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• 2016

Recently, the u-IT applications for plants and livestock become larger and control of livestock farm environment has been used important in the field of industry. We implemented wireless sensor networks and farm environment automatic control system for applying to the breeding barn environment by calculating the THI index. First, we gathered environmental information like livestock object temperature, heart rate and momentum. And we also collected the farm environment data including temperature, humidity and illuminance for calculating the THI index. Then we provide accurate control action roof open and electric fan in of intelligent farm to keep the best state automatically by using collected data. We believed this technology can improve industrial competitiveness through the u-IT based smart integrated management system introduction for industry aversion and dairy industries labor shortages due to hard work and old ageing.

• 조명전기설비학회논문지
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• 제26권2호
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• pp.44-50
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• 2012

When the fiber Bragg gratings are embedded in a fiber-optic Sagnac loop for measuring temperature or strain, it is difficult to separate the Bragg wavelengths. The transmitted light is mixed with the reflected Bragg wavelengths in the photo-detector, working as noises. To suppress the noises, we placed the FBG sensors and a fiber-optic attenuator at asymmetric positions in the loop. With the arrangement the reflected light became much bigger than the transmitted light, enabling the separation of the reflected Bragg wavelengths with almost the same signal-to-noise ratio of the FBG sensors outside the loop.

• 한국융합학회논문지
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• 제13권4호
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• pp.53-61
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• 2022

LNG 저장 작업 중 기계결함, 부주의 등으로 인해 사고가 꾸준히 발생하고 있다. 이전 연구에서는 위험을 미리 감지하는 압력, 온도, 가스 농도, 플로우 측정이 가능한 환경 센서 모듈을 개발하고 누출된 가스량에 따른 응답속도를 측정하였었다. 본 논문에서는 환경 센서 모듈이 측정한 데이터를 SPI, UART, LTE의 유무선 네트워크와 연결된 임베디드 기기들에 안전하게 전송해주는 유무선 통신 모듈의 개발을 제안한다. 먼저 환경 센서와 연동 가능한 데이터 통신 모듈을 설계한다. Local Control Part의 각 장치간 프로토콜과 Local Control Part와 Remote Control Part의 유무선 프로토콜을 설계한다. 이더넷, WiFi, LTE 통신 모듈을 설계하고 임베디드 제어기와 연동 가능한 UART, SPI 채널을 설계하였다. 그 결과, 각 임베디드 기기가 유선, 무선 동시 통신하면서 환경 센서 모듈이 측정한 데이터를 전송함을 UI(User Interface)를 통해 확인할 수 있었다.

• Tribology and Lubricants
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• 제29권6호
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• pp.372-377
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• 2013

This study investigated the interface temperatures for the sliding friction of three types of pins fabricated with thermocouple wires by the suction casting method. Optical microscopy was used to examine the surrounding material state at the bonding interface with the thermocouple wires. Friction tests were performed under dry sliding conditions against stainless steel 304 at nominal stresses of 1.42-4.25 MPa and sliding speeds of 0.5-1.25 m/s. Tribological data were collected using a custom-made pin-on-disk apparatus that measured the interface temperature and corresponding friction coefficient. Static tests were performed to demonstrate the functionality and reliability of the thermocouple wires-combined temperature sensor (TCTS). Each TCTS showed good linearity and sensitivity and very similar response times for the thermocouple and critical temperature during sliding friction.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.479-480
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• 2007

It is study about implementation of the home network system that used an ubiquitous sensor network and an embedded system in this paper. PXA270 and CC2420 were used, and the home server of a wireless sensor home network system composed it. A wireless control system is composed of a gas valve, a DC motor, a lamp and a door rock. A wireless detection system is composed of a gas detection sensor, a movement detection sensor, an extension detection sensor The wireless detection system that was an environment sensing system was composed of temperature, humidity, mic, illuminance, a speed-up, infrared rays temperature sensing module, and modular, other RFID established an USB camera, and an ubiquitous home network was composed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.479-482
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• 2003

We propose a real time gas monitoring system for classifying various gases with different concentrations. Using thermal modulation of operating temperature of two sensors, we extract patterns of gases from the voltage across the load resistance. We adopt the relative resistance as a pre-processing method and an ART2 neural network as a pattern recognition method. The proposed method has been implemented in a real time embedded system with tin oxide gas sensors, TGS 2611, 2602 and an MSP430 ultra-low power microcontroller in the test chamber.

• 센서학회지
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• 제16권2호
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• pp.142-149
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• 2007

Wireless sensor network technology is an emerging technology consisting of small, low power, and low cost devices that integrate limited computation, sensing, and radio communication capabilities. An ad-hoc home network system based embedded system for home environment monitoring was fabricated and tested. The wireless sensor node consists of a MCU, RF transceiver and sensors (temperature, humidity and light). Wireless sensor nodes run application software for data sampling and wireless communication, that was developed using 'nesC language' which runs on TinyOS. In our tests, acquired sensors data were monitored on 6.4" TFT-LCD of base-station through IEEE802.15.4 standard wireless communication. Also, the sensor data can be monitored by client user at the terminal PC to monitor environmental status of home in real time.

• Transactions on Electrical and Electronic Materials
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• 제13권2호
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• pp.106-109
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• 2012

A low power methane gas sensor with microheater was fabricated by silicon bulk micromachining technology. In order to heat up the sensing layer to operating temperature, a platinum (Pt) micro heater was embedded in the gas sensor. The line width and gap of the microheater was 20 ${\mu}m$ and 4.5 ${\mu}m$, respectively. Zinc oxide (ZnO) nanowhisker arrays were grown on a sensor from a ZnO seed layer using a hydrothermal method. A 200 ml aqueous solution of 0.1 mol zinc nitrate hexahydrate, 0.1 mol hexamethylenetetramine, and 0.02 mol polyethylenimine was used for growing ZnO nanowhiskers. Temperature distribution of the sensor was analyzed by infrared thermal camera. The optimum temperature for highest sensitivity was found to be $250^{\circ}C$ although relatively high (64%) sensitivity was obtained even at as low a temperature as $150^{\circ}C$. The power consumption was 72 mW at $250^{\circ}C$, and only 25 mW at $150^{\circ}C$.

• Transactions on Electrical and Electronic Materials
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• 제13권1호
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• pp.27-30
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• 2012

This paper proposes a micro gas sensor for measuring $H_2S$ gas. This is based on a $SnO_2$-CuO multi-layer thin film. The sensor has a silicon diaphragm, micro heater, and sensing layers. The micro heater is embedded in the sensing layer in order to increase the temperature to an operating temperature. The $SnO_2$-CuO multi layer film is prepared by the alternating deposition method and thermal oxidation which uses an electron beam evaporator and a thermal furnace. To determine the effect of the number of layers, five sets of films are prepared, each with different number of layers. The sensitivities are measured by applying $H_2S$ gas. It has a concentration of 1 ppm at an operating temperature of $270^{\circ}C$. At the same total thickness, the sensitivity of the sensor with multi sensing layers was improved, compared to the sensor with one sensing layer. The sensitivity of the sensor with five layers to 1 ppm of $H_2S$ gas is approximately 68%. This is approximately 12% more than that of a sensor with one-layer.