• 대한전기학회논문지:시스템및제어부문D
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• 제51권1호
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• pp.32-38
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• 2002

This paper describes a development of a portable physical activity monitoring system using two accelerometers to quantify physical activity. The system hardware consists of two piezoresistive accelerometers, amplifiers with gain of 30, lowpass filters with cut-off frequency of 15Hz, offset control circuits, one-chip microcontroller and flash memory card. In order to evaluate the performance of the system we acquired 3 channel data at 32 sample/sec from body-fixed accelerometers in chest and right upper leg. And then the acquired data were processed by MatLab on personal computer. We tried to distinguish not only fundamental actions which are steady-state activities such as standing, sitting, and lying but also dynamic activities with walking, up a stairway, down a stairway, and running. Five subjects participated the evaluation process which compare the video data with the measured data. As a result, the activity classification rate of 90.6% on average was obtained. Overall results showed that the steady-state activities could be classified from the low component of 3-axis acceleration signal and dynamic activities could be distinguished from frequency analysis using wavelet transform and FFT. Finally, we could find that this system can be applied to acquire and analyze the static and dynamic physical activity data.

• 전기학회논문지
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• 제57권6호
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• pp.1102-1108
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• 2008

Wearable physiological signal monitoring systems are regarded as an important sensing unit platforms in ubiquitous/mobile healthcare application. In this paper, we suggested the modified bipolar electrodes implemented on the portable heart activity monitoring system, which minimized the distance of electrodes formed on a attachable pad. The proposed electrode configuration is useful in mobile measurement environments, but has a disadvantage of reduced amplitude of the heart action potential. In order to overcome the shortcoming of the suggested electrode configuration, we implemented the amplifying circuit to increase the signal-gain and decrease the artifacts. For evaluations, we analyzed the specificity of measured cardiography using the proposed electrodes through the comparing of heart activity monitoring system with standard clinical ECG(lead2) by pearson correlation coefficients. The result showed that the average correlation coefficient is $0.903{\pm}0.036,\;0.873{\pm}0.072$ at V3, V4 chest lead position, respectively. Thus, the modified bipolar electrode is quite suitable to monitor the electrical activity of the heart in the situation of the mobile environment, and could be considered having high similarity with standard clinical ECG.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.703-706
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• 2007

인체의 실시간 활동 모니터링은 활동량과 활동능력에 대한 중요한 정보를 제공한다. 본 연구에서 3축 가속도 센서와 무선센서노드를 활용하여 인체의 활동을 평가하고 응급상황을 인지할 수 있는 시스템을 개발하였다. 본 연구에 의해 구현된 실시간 시스템은 구현된 분류알고리즘을 통해 다양한 자세와 자세변화를 분류할 수 있으며, 추가적으로 낙상을 감지할 수 있다. 구현된 시스템의 성능평가 결과 높은 분류 정확성을 보였다.

• Journal of information and communication convergence engineering
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• 제5권1호
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• pp.7-11
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• 2007

The aim of this paper is to design and implement a new ECG signal monitoring and analysis method for the home care of elderly persons or patients, using wireless sensor network (WSN) technology. The wireless technology for home-care purpose gives new possibilities for monitoring of vital parameter with wearable biomedical sensors and will give the patient freedom to be mobile and still be under continuously monitoring. Developed platform for portable real-time analysis of ECG signals can be used as an advanced diagnosis and alarming system. The ECG features are used to detect life-threatening arrhythmias, with an emphasis on the software for analyzing the P-wave, QRS complex, and T-wave in ECG signals at server after receiving data from base station. Based on abnormal ECG activity, the server transfer diagnostic results and alarm conditions to a doctor's PDA. Doctor can diagnose the patients who have survived from arrhythmia diseases.

• 대한교통학회지
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• 제33권5호
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• pp.449-460
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• 2015

현재 교통수요모형 기반의 자동차 배출량 추정 모형에서 교통 활동도 자료는 세부적으로 고려되는 반면, 배출계수는 평균적인 값만 반영되고 있기 때문에 배출량 산정 결과의 정확도를 저하시키는 문제가 있다. 본 연구는 도로유형 및 주행시간대와 무관하게 동일한 배출계수가 적용되는 부분을 개선하기 위해, 도로유형과 주행시간대별 연료소모량 차이에 대한 실증적 분석을 기반으로 각 유형별 배출계수의 보정 지표 제시를 목적으로 한다. 이를 위해, '이동식 차량활동도 모니터링 장비(Portable Activity Monitoring System: PAMS)'를 이용해 도로유형 주행시간대별 실 주행 자료를 수집하였고, 각 유형별 연료소모량을 추정하여 이를 비교하였다. 연구 결과 평균 주행속도가 22.5km/h 일 경우, 도로 유형별 주행차량의 가감속도 변화 등의 차이에 따라 국도에서의 연료소모량(95g/km)은 자동차 전용도로에서(81g/km)보다 약 17.3% 높은 것으로 분석되었고, 첨두시간대의 평균 연료소모량(86.73g/km)은 비첨두시간대(82.84g/km)보다 약 4.7% 높은 것으로 분석되었다. 각 유형별 연료소모량의 차이는 공변량 분석 (ANOCOVA)과 다변량 분산분석 (MANOVA)으로 검증하였으며, 그 결과 "주행속도가 동일할지라도, 도로유형과 주행시간대에 따라 연료소모량의 차이가 있다"는 본 연구가설은 유의한 것으로 나타났다. 마지막으로 연료소모량의 차이를 활용하여 각 유형별 배출계수 보정 지표들을 제안하였다. 본 연구는 기존 차량 중심의 배출계수 연구에서 벗어나, 도로 교통 조건에 따른 배출계수 특성을 분석했다는 점에서 의의가 있으며, 본 연구결과를 활용하여 교통부문의 배출량 추정결과에 대한 신뢰성을 향상시킬 수 있을 것으로 기대한다.

• International journal of advanced smart convergence
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• 제6권3호
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• pp.38-44
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• 2017

Currently, wired gables have been installed or portable storage devices have been installed for data acquisition of flying drone. In this paper, we propose a technology to transmit data wirelessly by sensing information such as battery discharge value, acceleration, and temperature by attaching RF sensor to a drone. The purpose of this paper is to design and develop the monitoring technology of agriculture drone battery usage in real time using RF sensor. In this paper, we propose a monitoring system that can check real time data of battery changed value, temperature, and acceleration during pesticide control activity of agricultural drone.

• Environmental Analysis Health and Toxicology
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• 제19권2호
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• pp.161-167
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• 2004

Air quality monitoring is a primary activity for industrial and social environment. The government identifies the pollutants that each industry must monitor. Especially, the VOCs (Volatile Organic Compounds), which are very harmful to human body and environment atmosphere, should be controlled under the government policy. However, the VOCs, which have not been confirmed in emission sources are very difficult to monitor. It is needed to develop the monitoring system that allow the continuous and in situ measurement of VOCs mixture in different environmental matrices. Gas chromatography and mass spectrometry are the most prevalent current techniques among those available for the analysis of VOCs. But, they need a large size analytical instrument, which costs a great deal for purchase and operation. In addition, it has some limitations for realtime environmental monitoring such as location problems and slow processing time. Recently, several companies have commercialized a portable VOCs measurement systems, which cannot classify various kinds of VOCs but total quantities. We have developed a VOCs measurement system, which recognizes various kinds and quantities of VOCs, such as benzene, toluene, and xylene (BTX). Also, it can be used as a stand- alone type and/or fixed type in the vehicle with rack for real -time environmental monitoring.

• 대한임베디드공학회논문지
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• 제8권5호
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• pp.273-283
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• 2013

The traditional medical equipments are devices used by medical professionals but not used in public environment. Common people, however, require light-weight medical devices to make healthcare for themselves nowadays. Those medical devices are used to monitor personal health status such as blood pulse, blood pressure, diabetes. Also, some of them are operated in mobile environment called u-healthcare. This paper implements a portable healthcare system composed of $SpO_2$(Saturation of Partial Pressure Oxygen) sensors and a gateway for detecting hypoxemia during people's leasure activity such as climbing or hiking. The $SpO_2$ sensor is designed as watch style to support dynamic exercise and the gateway is designed as necklace style to support the elderly. The result of a performance evaluation shows that the performance of the $SpO_2$ sensor using reflection technology is not lower than that of a clairvoyant styled $SpO_2$ sensor.

• 전기학회논문지
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• 제59권6호
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• pp.1150-1158
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• 2010

In this paper, a new reliable portable activity monitoring device implemented with the buddhist-style bowing activity and walking step detection algorithm, is presented. In order to monitor the bowing and walking activities, miniaturized 3-axis accelerometer sensor with the sensitivity of 800 mV/g was used. After initial signal conditioning, vector magnitude of accelerometer signals was calculated. Syntactic peak detection method was used in order to feature points. All signal processing algorithms were implemented in ultra-low power microcontroller MSP430 with double precision floating point arithmetic. For evaluation, 19 young man($24.22\pm5.22$ yrs) and woman($22.28\pm2.72$ yrs) were involved. The accuracy of the proposed algorithms were 98.91 %($\pm0.011$) for walking step detection and 98.25 %($\pm0.023$) for buddhist-style bowing activity. Comparing to the commercialized pedometer accuracy, 87.1 %($\pm0.058$), the proposed walking step detection algorithms show more reliable accuracy.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.324-327
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• 2015

Scaffold is the most commonly used equipment in various types of construction works. Since various types of construction works use the same scaffold equipment, it becomes more difficult to be controlled and managed, thus resulting hazard frequently. According to the information announced in July 2012 by Council of Labor Affairs Executive Yan, the site collapse or incomplete anti-falling protection has led the site to accident frequently, and this is the main reason that causes construction industry occupational disasters. The labor death occupational hazard ratio rises up to 13% in scaffold activity, and the Council of Labor Affairs Executive Yan has showed that the death ratio is higher when using the scaffold in construction site, the total number of death has reached to 139 from 2005 to 2010. In order to ensure the safety of scaffold user, this study tends to build a wireless sensor monitoring system to detect the reliability and safety of the scaffold. The wireless sensor technique applies in this study is different with the traditional monitoring technique which is limited with wired monitoring. Wireless sensor technique does not need wire, it just needs to consider the power supply for establishing the network and receiving stable information, and it can become a monitoring system. In addition, this study also integrates strain gauge technique in this scaffold monitoring system, to develop a real-time monitoring data transfer mechanism and replace the traditional wired single project monitoring equipment. This study hopes to build a scaffold collapse monitoring system to effectively monitor the safety of the scaffold as well as provide the timesaving installation, low-cost and portable features.