• 전기학회논문지
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• 제65권12호
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• pp.2075-2083
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• 2016

The real time IAQ (Indoor Air Quality) management is very important for large buildings and underground facilities such as subways because poor IAQ is immediately harmful to human health. Such IAQ management requires monitoring, prediction and control in an integrated and real time manner. In this paper, we present three PM10 hourly prediction models for such realtime IAQ management as both Multiple Linear Regression (MLR) and Artificial Neural Network (ANN) models. Both MLR and ANN models show good performances between 0.76 and 0.88 with respect to R (correlation coefficient) between the measured and predicted values, but the MLR models outperform the corresponding ANN models with respect to RMSE (root mean square error).

• 한국해양공학회지
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• 제13권1호통권31호
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• pp.88-93
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• 1999

This paper presents the experimental examinations and statistical quantitative analysis of the correlation between the cumulative counts of acoustic emission(AE) during plastic deformation periods of the welding and the tensile strength and other properties of the bar-to-bar welded joints of O.D. 16mm shaft(SM40C) as well as the various welding variables. And this is a new approach which attempts finally to develop real-time quality monitoring system for friction welding. The results lead to a practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro structural defects.

• 한국해양공학회지
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• 제18권2호
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• pp.25-32
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• 2004

We surveyed the coastal structure damage created by typhoon ‘Maemi’, which heavily struck the Korean peninsula on September 12, 2003. The survey revealed that high tides and strong winds induced by the typhoon were the main causes of the coastal damage, especially in the Busan areas. Though some experimental real-time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete system should be implemented to save human lives and property from huge typhoon disasters.

• Smart Structures and Systems
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• 제19권6호
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• pp.587-599
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• 2017

This paper introduces an approach to the realization of an ICT-based bridge remote monitoring system that enables real-time monitoring and controlled adjustments for unexpected heavy loads and also for damaging earthquakes or typhoons. In this paper, an integrated bridge remote monitoring system called the "Intelligent Bridge", which consists of a stand-alone monitoring system (SMS) and a web-based Internet monitoring system(IMS), was developed for not only bridge maintenance but also as an application for a para-stressing bridge system. To verify the possibility of controlling the actual structural performance of an "Intelligent Bridge", a model 2-span continuous cable-stayed bridge with adjustable cables was constructed. The experimental results demonstrate that the implemented monitoring system supplies detailed and accurate information about bridge behaviour for further evaluation and diagnosis, and it also opens up prospects for future application of a web-based remote system to actually adjust in-service bridges under field conditions.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.320-320
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• 2013

Film thickness monitoring with plasma impedance monitoring (PIM) is demonstrated for small area $SiO_2$ RF plasma etching processes in this work. The chamber conditions were monitored by the impedance signal variation from the I-V monitoring system. Moreover, modified principal component analysis (mPCA) was applied to estimate the $SiO_2$ film thickness. For verification, the PIM was compared with optical emission spectroscopy (OES) signals which are widely used in the semiconductor industry. The results indicated that film thickness can be estimated by 1st principal component (PC) and 2nd PC. Film thickness monitoring of small area $SiO_2$ etching was successfully demonstrated with RF plasma harmonic impedance monitoring and mPCA. We believe that this technique can be potentially applied to plasma etching processes as a sensitive process monitoring tool.

• Smart Structures and Systems
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• 제24권6호
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• pp.769-781
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• 2019

Dynamic displacement response of civil structures is an important index for in-construction and in-service structural condition assessment. However, accurately measuring the displacement of large-scale civil structures such as high-rise buildings still remains as a challenging task. In order to cope with this problem, a vision-based system with the use of industrial digital camera and image processing has been developed for long-distance, remote, and real-time monitoring of dynamic displacement of supertall structures. Instead of acquiring image signals, the proposed system traces only the coordinates of the target points, therefore enabling real-time monitoring and display of displacement responses in a relatively high sampling rate. This study addresses the in-situ experimental verification of the developed vision-based system on the Canton Tower of 600 m high. To facilitate the verification, a GPS system is used to calibrate/verify the structural displacement responses measured by the vision-based system. Meanwhile, an accelerometer deployed in the vicinity of the target point also provides frequency-domain information for comparison. Special attention has been given on understanding the influence of the surrounding light on the monitoring results. For this purpose, the experimental tests are conducted in daytime and nighttime through placing the vision-based system outside the tower (in a brilliant environment) and inside the tower (in a dark environment), respectively. The results indicate that the displacement response time histories monitored by the vision-based system not only match well with those acquired by the GPS receiver, but also have higher fidelity and are less noise-corrupted. In addition, the low-order modal frequencies of the building identified with use of the data obtained from the vision-based system are all in good agreement with those obtained from the accelerometer, the GPS receiver and an elaborate finite element model. Especially, the vision-based system placed at the bottom of the enclosed elevator shaft offers better monitoring data compared with the system placed outside the tower. Based on a wavelet filtering technique, the displacement response time histories obtained by the vision-based system are easily decomposed into two parts: a quasi-static ingredient primarily resulting from temperature variation and a dynamic component mainly caused by fluctuating wind load.

• 한국멀티미디어학회논문지
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• 제20권5호
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• pp.808-826
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• 2017

Most of conventional DSS's(Digital Signage Systems) have been built based on LAMP framework. Recent researches have shown that MEAN or MERN stack framework is simpler, more flexible, faster and more suitable for web-based application than LAMP stack framework. In this paper, we propose a design and implementation of MEARN (ME(A+R)N) stack-based real-time digital signage system, MR-DSS, which supports handing real-time tasks like urgent/instant messaging, system status monitoring and so on, efficiently in addition to conventional digital signage CMS service tasks. MR-DSCMS, CMS of MR-DSS, is designed to provide most of its normal services by REST APIs and real-time services like urgent/instant messaging by Socket.IO base under MEARN stack environment. In addition to architecture description of components composing MR-DSS, design and implementation issues are clarified in more detail. Through experimental testing, it is shown that 1) MR-DSS works functionally well, 2) the networking load performance of MR-DSCMS's REST APIs is better compared to a well-known open source Xibo CMS, and 3) real-time messaging via Socket.IO works much faster than REST APIs.

• 전자공학회논문지SC
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• 제45권4호
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• pp.42-50
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• 2008

본 논문에서는 원격 의료 서비스를 위한 생체 신호 취득 및 전송 시스템의 실시간 신뢰성을 보장하기 위하여 ZigBee와 SIP/RTP를 기반으로 하는 실시간 생체 신호 전송 시스템의 성능 개선 방법을 제안하고 구현하였다. 기존의 시스템은 ZigBee기반의 유비쿼터스 센서 네트워크를 기반으로 사용자의 ECG 및 기타 생체 신호를 수집한다. 이 때 연속된 ECG 전송에 의하여 채널이 과다하게 점유되어 ECG 이외의 생체 신호를 전송할 때 패킷의 손실이 발생한다. 또한 하나의 RTP 세션을 통해 사용자의 음성과 ECG 및 기타 생체 신호를 순차적으로 전송하기 때문에 과중한 전송 스레드 부하와 지연이 발생한다. 따라서 본 논문에서는 ECG 전송 모듈의 채널 점유 문제를 해결하기 위해 Bluetooth를 보조 전송 수단으로 사용하고 복수의 RTP 세션과 전송 스레드를 사용하여 전송지연을 감소시키는 방법을 사용하였다. 또한 이산 웨이블릿 리프팅과 다단계 벡터 양자화 기반의 압축 방법을 적용하여 전송 및 저장되는 ECG를 압축하여 관리하는 구조를 제안하고 구현하였다. ECG의 압축은 데이터의 전송량을 감소시켜 시스템의 실시간 신뢰성을 향상시키며 데이터베이스의 저장 공간을 효율적으로 사용할 수 있도록 한다. 결과적으로 기존의 시스템에 대하여 유비쿼터스 센서 네트워크의 안정성을 확보할 수 있었고 실시간 전송 모듈의 프로세스 점유율을 약 20% 감소시킬 수 있었으며 실제 측정한 ECG를 압축한 결과 25.6:1의 압축률에서 약 3.25%의 PRD를 가지는 효율적인 ECG 관리가 이루어질 수 있었다.

• 한국산업정보학회논문지
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• 제19권3호
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• pp.57-66
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• 2014

본 논문은 RFID를 이용하여 환자, 의료진, 의약품을 관리하는 UHISRL(Ubiquitous Healthcare Information System based on Real Time Location)을 제안하였다. 제안하는 UHISRL은 환자의 건강상태를 모니터링하고, 그 결과를 스마트 폰과 태블릿 PC로 확인할 수 있다. 또한, 본 논문에서 설계된 ERHL(Extended Randomized Hash Lock) 인증 기법을 사용하여 재전송공격과 스푸핑 공격을 차단하였고, 환자의 프라이버시는 CP-ABE(Cipher Text - Attributed based Encryption)기법을 이용하여 UHISRL DB 접근을 속성에 따라 제한함으로써 보안을 강화시켰다. 특히, UHISRL는 만성질환자의 응급 상황을 실시간으로 모니터링 함으로써 불의의 사고를 방지할 수 있도록 하였다.

• 한국컴퓨터정보학회논문지
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• 제7권4호
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• pp.52-58
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• 2002

본 논문은 가변 탐색창을 이용하여 실시간으로 객체를 추적하는 방법에 대해 기술한다. 동영상에서 실시간 객체 추적은 카메라를 이용한 감시 시스템에 필요한데, 감시 대상 환경에 따라 효율성이 크게 좌우된다. 먼저 입력영상과 배경영상의 차를 이용하여 객체의 위치를 탐지하는데, 이를 위해서 객체의 윤곽선과 무게중심을 추출한다. 그리고 객체의 크기와 위치로부터 설정한 가변 탐색창을 이용하여 탐지된 객체의 움직임을 추적한다. 이 때 배경영상과 카메라는 고정된 환경으로 제한한다. 제안 방법의 실험 결과 초당 17-23 프레임으로 기존의 객체 추적 방법들의 평균 10-14 프레임보다 빠른 처리 속도를 나타내었다.