• 한국전기전자재료학회논문지
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• 제29권5호
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• pp.284-288
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• 2016

Among the various physiological information that could be obtained from human body, heartbeat rate is a commonly used vital sign in the clinical milieu. Photoplethysography (PPG) sensor is incorporated into many wearable healthcare devices because of its advantages such as simplicity of hardware structure and low-cost. However, healthcare device employing PPG sensor has been issued in susceptibility of light and motion artifact. In this paper, to develop the real-time heart rate measurement device that is less sensitive to the external noises, we have fabricated an ultra-small wireless LC resonant pressure sensor by MEMS process. After performance evaluation in linearity and repeatability of the MEMS pressure sensor, heartbeat waveform and rate on radial artery were obtained by using resonant frequency-pressure conversion method. The measured data using the proposed heartbeat rate measurement system was validated by comparing it with the data of an commercialized heart rate measurement device. Result of the proposed device was agreed well to that of the commercialized device. The obtained real time heartbeat wave and rate were displayed on personal mobile system by bluetooth communication.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.64-64
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• 2009

As the advanced packaging technology developing, Copper electro-plating processing has be wildly utilized in the semiconductor interconnect technique. Chemical solution monitoring methods, including PH and gravity measurement exist in industry, but economical and practical real-time monitoring has not been achieved yet. Red-green-blue (RGB) color sensor can successfully monitor the condition of $CuSO_4$ solution during electric copper plating process. Comparing the intensity variations of the RGB data and optical spectroscopy data, strong correlation between two in-situ sensors have shown.

• 인터넷정보학회논문지
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• 제16권6호
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• pp.31-37
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• 2015

최근 사물인터넷 발달로 인하여 센서에서 발생되는 데이터가 폭증하고 있다. 이러한 패러다임의 변화로 즉각 행동이 요구되는 여러 산업현장에서 실시간으로 발생되는 데이터들의 분석이 필요하게 되었으며, 실시간 시각화 분석이 대두되고 있다. 그러나 기존 시각화 시스템은 데이터를 저장 후에 시각화를 하기 때문에 서버의 응답시간이 실시간에 준하는 ms수준의 처리를 보장하지 못하며, 처리할 자원을 보유하고 있지 않아 주요 자원이 될 데이터를 폐기하는 문제가 발생한다. 따라서 본 논문에서는 가드닝 환경에서 IoT 센싱 정보를 활용하여 실시간 시각화 알고리즘을 적용한 스마트가드닝 시스템을 설계 및 구현하였다. 제안 시스템의 성능 평가를 위하여 서버의 응답시간을 측정하였고, 테스트 결과 제안하는 실시간 시각화 알고리즘의 응답 속도는 실시간에 준하는 ms수준의 처리를 보장함을 확인하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.172-172
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• 2023

The use of low-cost IoT sensors for flow measurement in open channels has gained significant attention due to their potential to provide continuous and real-time data at a low cost. However, the accuracy and reliability of these sensors in real-world scenarios are not well understood. This study aims to compare the performance of low-cost IoT sensors in the laboratory and real-world conditions to evaluate their accuracy and reliability. Firstly, a low-cost IoT sensor was integrated with an IoT platform to acquire real-time flow rate data. The IoT sensors were calibrated in the laboratory environment to optimize their accuracy, including different types of low-cost IoT sensors (HC-SR04 ultrasonic sensor & YF-S201 sensor) using an open channel prototype. After calibration, the IoT sensors were then applied to a real-world case study in the Dorim-cheon stream, where they were compared to traditional flow measurement methods to evaluate their accuracy.The results showed that the low-cost IoT sensors provided accurate and reliable flow rate data under laboratory conditions, with an error range of less than 5%. However, when applied to the real-world case study, the accuracy of the IoT sensors decreased, which could be attributed to several factors such as the effects of water turbulence, sensor drift, and environmental factors. Overall, this study highlights the potential of low-cost IoT sensors for flow measurement in open channels and provides insights into their limitations and challenges in real-world scenarios.

• 조명전기설비학회논문지
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• 제25권2호
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• pp.96-102
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• 2011

There are many problems with the fire detection devices being used in currently, because it is difficult to find location of the source of fire and determine where devices are working or not. In this paper, we proposed fire detection and rescue system using wireless sensor network that can be real-time monitoring and determine safe exit. Fire detection and rescue system based on ubiquitous sensor network can know exactly source of fire and help determine rescue tactics using sensing data from wireless sensor nodes. Transmitted wirelessly in real-time thermal sensor and gas sensor information to analyze the GUI to monitor the status information output to the screen by use of a system implemented in everyday life, looked at the possibility.

• Journal of information and communication convergence engineering
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• 제14권2호
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• pp.84-88
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• 2016

As good example of potential application-specific requirement, (m,k)-firm real-time streams have been recently introduced to deliver multimedia data efficiently in wireless sensor networks. In addition to stream model, communication protocols to meet specific (m,k)-firm real-time streams have been newly developed or extended from existing protocols. However, since the existing schemes for an (m,k)-firm stream have been proposed under typical flat architecture, the scalability problem remains unsolved when the number of real-time flows increases in the networks. To solve this problem, in this paper, we propose a new clustering scheme for an (m,k)-firm stream. The two different clustering algorithms are performed according to either the (m,k)-firm requirement or the deadline. Simulation results are presented to demonstrate the suitability of the proposed scheme under hierarchical architecture by showing that its performance is acceptable irrespective of the increase in the number of flows.

• 한국전자거래학회지
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• 제13권2호
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• pp.149-163
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• 2008

센서 네트워크에서는 데이터의 실시간 처리가 중요한 요소 중의 하나이다. 각 노드들이 감지한 데이터를 정해진 시간 내에 전달해야 필요한 시기에 적합한 처리가 가능하다. 따라서 노드들이 데이터를 정해진 시간 내에 제대로 전달하고 있는가를 점검하는 것은 매우 중요하다. 이에 따라 본 논문에서는 데이터 전송시간에 대한 모니터링을 통하여 센서 네트워크에 존재하는 노드들이 허용시간 범위 내에서 서버로 데이터를 전송하고 있는가를 확인하기 위한 데이터 전송시간 분석 시스템의 구현 사례를 제안한다. 이를 위하여 데이터 전송시간 분석을 위한 절차를 제시하고, 제시한 절차에 따라 전송시간을 분석하기 위해 필요한 시간차 분석 방법, 데이터 송수신 시간 수집 방법 및 데이터 전송시간 계산 방법을 제시한다. 또한 제시한 방법을 바탕으로 데이터 전송시간을 모니터링하고 분석하기 위한 시스템을 구현하고, 사례 연구를 수행한 결과를 보인다.

• 자동차안전학회지
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• 제12권1호
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• pp.52-61
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• 2020

In recent years, the increasing interest in health-care requires the industrial products to be well-designed ergonomically. In the commercial vehicle industry, several researchers have demonstrated the driver's posture has great effect on the orthopedic desease such as fatigue, back pain, scoliosis, and so on. However, the existing sensor systems developed for measuring the driver posture in real time have suffered from inaccuracy and low reliability issues. Here, we suggest our smart vehicle seat system capable of real-time driver posture monitoring by using the air bag sensor package with high sensitivity and reliability. The ergonomic numerical model which can evaluate a driver's posture has been developed on the basis of the human body segmentation method followed by simulation-based validation. Our experimental analysis of obtained pressure distribution of a vehicle seat under the different driver's postures revealed our smart vehicle system successfully achieved the driver's real-time posture data in great agreement with our numerical model.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.253-257
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• 2004

Neural networks are works are used in the framework of sensor based tracking control of robot manipulators. They learn by practice movements the relationship between PSD(an analog Position Sensitive Detector) sensor readings for target positions and the joint commands to reach them. Using this configuration, the system can track or follow a moving or stationary object in real time. Furthermore, an efficient neural network architecture has been developed for real time learning. This network uses multiple sets of simple back propagation networks one of which is selected according to which division(corresponding to a cluster of the self-organizing feature map) in data space the current input data belongs to. This lends itself to a very training and processing implementation required for real time control.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.141-146
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• 2008

최근 유비쿼터스 환경에서의 다양한 서비스에 대한 연구가 활발히 진행되고 있다. 이러한 서비스들은 사용자의 컨텍스트를 해석하는 것이 중요하며, 이를 위해 PDA, GPS, 가속도 센서 등 다양한 센서들이 활용되고 있다. 가속도 센서와 같은 저급의 연속적인 데이터를 수집하는 센서는 그 데이터를 직접 활용하는 것이 어려우므로 전처리 하는 것이 중요하다. 하지만 실시간으로 전처리하고 컨텍스트를 통합하는 시스템에 대한 연구가 미흡하다. 본 논문에서는 XMI 을 활용하여 가속도 센서와 생리적 신호 센서 등과 같은 저급의 데이터를 전처리하고 컨텍스트를 통합하는 시스템을 제안한다. XML을 통하여 센서 네트워크의 구조를 정의하고, 각 센서별로 수집되는 데이터와 데이터에 해당하는 컨텍스트의 룰을 정의할 수 있다. 제안하는 시스템은 XML을 통하여 센서 네트워크에 센서를 추가할 때와 컨텍스트의 룰을 수정할 때 소스의 수정을 줄여준다. 그리고 이 시스템을 활용하여 실시간으로 데이터를 모니터링하는 시스템을 구현하여 난해한 데이터의 변화를 그래프로 표현해 데이터의 검증을 도와주며, 실시간으로 전처리의 결과를 확인하여 변화가 가능하고, 다른 외부 서비스나 어플리케이션에 사용자의 컨텍스트의 제공을 용이하게 해준다.