• 제목/요약/키워드: Real-time sensor

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ECA 기반 센서 네트워크 실시간 모니터링 서비스 (Real-Time Sensor Monitoring Service based on ECA)

  • 김정이
    • 한국멀티미디어학회논문지
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    • 제15권1호
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    • pp.87-92
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    • 2012
  • 무선 센서 네트워크는 실시간으로 객체에 대한 정보를 수집하기 위한 기술로 짧은 시간에 많은 양의 데이터가 지속적으로 발생되는 특성을 갖고 있다. 센서로부터 획득되는 많은 양의 데이터 스트림을 효과적으로 처리하기 위해서는 데이터 간의 관계를 정의하여 분석, 사용자가 주목할 만한 상황, 즉 센서 데이터들 중 이상 데이터가 포함되어 있는 것을 발견하는 것이 필수적이라 할 수 있다. 본 논문에서는 센서 데이터 스트림을 효과적으로 처리하기 위해 ECA 규칙을 사용하여 의미있는 데이터를 구성하고, 이를 통해 보다 실용적인 실시간 모니터링 시스템을 제안한다.

${\mu}TMO$ 모델 기반 실시간 센서 네트워크 운영체제 ([ ${\mu}TMO$ ] Model based Real-Time Operating System for Sensor Network)

  • 이재안;허신;최병규
    • 한국정보과학회논문지:시스템및이론
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    • 제34권12호
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    • pp.630-640
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    • 2007
  • 센서 네트워크의 응용 범위가 점차 넓어지면서 군사 분야나 방사능 감지와 같이 실시간성을 요구하는 응용분야가 생겨나게 되었다. 하지만 기존의 센서 운영체제 연구는 효율적인 자원 활용에 초점을 두고 연구가 진행되었기 때문에 실시간성을 만족시켜 주기 어려운 구조를 가지고 있다. 본 논문에서는 정시성을 보장하는 실시간 분산 객체 TMO 모델을 센서 네트워크의 제한된 자원 환경에 알맞도록 경량화 시킨 ${\mu}TMO$ 모델을 제안한다. ${\mu}TMO$ 모델을 이용한 실시간 센서 네트워크 운영체제를 개발하기 위하여 한국전자통신연구원에서 개발한 센서 노드용 운영체제인 Nano-Q+를 이용하였다. Nano-Q+의 타이머 모듈을 높은 해상도를 가질 수 있도록 수정하였으며, EDF(Earliest-Deadline-First)기반의 실시간 스케줄러에 CST(Context Switch Threshold)와 PAS(Power Aware Scheduling) 기법을 적용하여 센서 노드에 적합한 실시간 스케줄러로 변경하였다. ${\mu}TMO$ 모델을 지원하기 위해 채널 기반의 통신 수단인 ITC-Channel을 새롭게 구현하였으며, 주기적인 스레드를 관리하는 WTMT(Watchdog TMO Management Task) 모듈을 구현하여 SpM 스레드를 주기에 맞게 실행할 수 있도록 하였다.

가설공사 안전관리를 위한 무선계측 시스템 적용 (Application of Wireless Measurement System for Safety Management of Temporary Substructures)

  • 인치훈;임홍철;이근우
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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    • pp.21-24
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    • 2009
  • This study deals with the application of USN wireless inclinometer sensor for earth retaining structure safety measurement, The application of wireless inclinometer sensor has great advantage about real-time monitoring of earth retaining structure, It allows a construction manager to monitor movement data from anywhere connected through internet during the process of excavation for substructures of buildings, To validate the applicability of the wireless inclinometer sensor. laboratory and field tests have been performed, The results have shown that the measured values of wireless inclinometer sensor represent the behavior of H-pile well, Both convenience of sensor installation and real-time monitoring of earth retaining structure are confirmed, The proposed wireless measurement system provides a good basis for exact measurement of temporary substructures, More measurements and application are expected for the other excavation sites with various conditions.

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광섬유 EFPI 센서를 이용한 나노 이송장치의 개발 (Development of nano-positioner using fiber optic EFPI sensor)

  • 박상욱;김대현;김천곤
    • 센서학회지
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    • 제14권5호
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    • pp.302-307
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    • 2005
  • Precision displacement of less than a few nm resolution was measured in real-time using fiber optic EFPI sensor. The novel method for real-time processing of analyzing EFPI output signal was developed and verified. Linearity in the mean values of interferometric light intensity among adjacent fringes was shown and verified the sinusoidal approximation algorithm that estimates past and coming fringe values. Real-time signal processing program was developed and the intensity signal of the EFPI sensor was transformed to the phase shift with this program. The resolution below $0.36{\sim}8.6$ nm in the displacement range of $0{\sim}300{\mu}m$ was obtained. The nano-positioner with a piezoelectric actuator and the EFPI sensor system was designed and tested. The positioner successfully reached to the desired destination within 1 nm accuracy.

Hierarchical Real-Time MAC Protocol for (m,k)-firm Stream in Wireless Sensor Networks

  • Teng, Zhang;Kim, Ki-Il
    • Journal of information and communication convergence engineering
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    • 제8권2호
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    • pp.212-218
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    • 2010
  • In wireless sensor networks (WSNs), both efficient energy management and Quality of Service (QoS) are important issues for some applications. For creating robust networks, real-time services are usually employed to satisfy the QoS requirements. In this paper, we proposed a hierarchical real-time MAC (medium access control) protocol for (m,k)-firm constraint in wireless sensor networks shortly called HRTS-MAC. The proposed HRTS-MAC protocol is based on a dynamic priority assignment by (m,k)-firm constraint. In a tree structure topology, the scheduling algorithm assigns uniform transmitting opportunities to each node. The paper also provides experimental results and comparison of the proposed protocol with E_DBP scheduling algorithm.

구조화된 실내 환경에서 초음파센서를 이용한 모바일 로봇 실시간 localization 기법 (Real-time Localization of Mobile Robot Using Ultrasonic Sensor in Structured Indoor Environment)

  • 이만희;조황
    • 제어로봇시스템학회논문지
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    • 제11권12호
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    • pp.1068-1076
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    • 2005
  • In order to increase the autonomous navigation capability of a mobile robot, it is very crucial to develop a method for the robot to be able to recognize a priori hon structured environmental characteristics. This paper proposes an ultrasonic sensor based real-time method for recognizing a priori known structured indoor environmental characteristics like a wall and comer Unlike the methods reported in the literature the information obtained from the sensor can be processed in real-time by extended Kalman filter to update estimations of the position and orientation of robot with respect to known environmental characteristics.

CMOS 이미지 센서를 위한 실시간 전처리 프로세서의 설계 (A Design of the Real-Time Preprocessor for CMOS image sensor)

  • 정윤호;이준환;김재석
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 추계종합학술대회 논문집
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    • pp.224-227
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    • 1999
  • This paper presents a design of the real-time preprocessor for CMOS image sensor suitable to the digital camera applications. CMOS image sensor offers some advantages in on-chip integration, system power reduction, and low cost. However, it has a lower-quality image than CCDs. We describe an image enhancement algorithm, which includes color interpolation, color correction, gamma correction, sharpening, and automatic exposure control, to compensate for this disadvantage, and present its efficient hardware architecture to implement on the real-time processor. The presented real-time preprocessor was designed using VHDL, and it contains about 19.2K logic gates. We also implement our system on FPGA chips in order to provide the real-time adjustment and it was successfully tested.

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광섬유격자 센서를 활용한 사면거동 실시간 안전 진단 시스템 (Real-Time Monitoring and Warning System for Slope Movements Using FBG Sensor.)

  • 장기태;정경선;김성환;박권제;이원효;김경태;강창국;홍성진
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 사면안정 학술발표회
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    • pp.60-76
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    • 2000
  • Early detection in real-time response of slope movements ensures tremendous saving of lives and repair costs from catastrophic disaster Therefore, it is essential to constantly monitor the performance and integrity of slope-stabilizing structures such as Rock bolt, Nail and Pile during or after installation. We developed a novel monitoring system using Fiber Bragg Grating (FBG)sensor. It's advantages are highly sensitivity, small dimension and electro-magnetic immunity. capability of multiplexing, system integrity, remote sensing - these serve real-time health monitoring of the structures. Real-time strain measurement by the signal processing program is shown graphically and it gives a warning sound when the monitored strain state exceeds a given threshold level so that any sign of abnormal disturbance on the spot can be easily perceived.

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Efficient Anomaly Detection Through Confidence Interval Estimation Based on Time Series Analysis

  • Kim, Yeong-Ju;Jeong, Min-A
    • International journal of advanced smart convergence
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    • 제4권2호
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    • pp.46-53
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    • 2015
  • This paper suggests a method of real time confidence interval estimation to detect abnormal states of sensor data. For real time confidence interval estimation, the mean square errors of the exponential smoothing method and moving average method, two of the time series analysis method, were compared, and the moving average method with less errors was applied. When the sensor data passes the bounds of the confidence interval estimation, the administrator is notified through alarms. As the suggested method is for real time anomaly detection in a ship, an Android terminal was adopted for better communication between the wireless sensor network and users. For safe navigation, an administrator can make decisions promptly and accurately upon emergency situation in a ship by referring to the anomaly detection information through real time confidence interval estimation.