• 제목/요약/키워드: Continuous Monitoring

검색결과 1,561건 처리시간 0.031초

In-service Real-time and Continuous Objective Video Quality Assessment for DTV Broadcasting

  • Han, Chan-Ho
    • 한국멀티미디어학회논문지
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    • 제16권1호
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    • pp.50-55
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    • 2013
  • This article presents a simple and reasonable in-service, real-time, and continuous single-ended objective video quality assessment model for DTV broadcasting using a multiburst signal at the bottom of the transient effect area, similar to Vertical Interval Test Signals. The issue of in-service video-quality monitoring in DTV broadcasting is addressed, and an effective method of quality monitoring is presented. The proposed method is also implemented and tested in a range of situations using a simulated HDTV broadcasting network.

Enhancement of Electrocatalytic Activity upon the Addition of Single Wall Carbon Nanotube to the Redox-hydrogel-based Glucose Sensor

  • Kim, Suk-Joon;Quan, Yuzhong;Ha, Eunhyeon;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • 제12권1호
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    • pp.33-37
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    • 2021
  • In electrochemical glucose sensing, the enhancement of the sensitivity and the response time is essential in developing stable and reliable sensors, especially for continuous glucose monitoring. We developed a method to increase the sensitivity and to shorten the response time for the sensing upon the appropriate addition of single wall carbon nanotube onto the osmium polymer-based hydrogel electrode. Also, the background stabilization is dramatically enhanced.

Application of Principal Components Analysis Method to Wireless Sensor Network Based Structural Monitoring Systems

  • Congyi, Zhang;Mission, Jose Leo;Kim, Sung-Ho;Youk, Yui-Su;Kim, Hyeong-Joo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제8권1호
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    • pp.11-17
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    • 2008
  • Typical wireless sensor networks used in structural monitoring are continuous types wherein data transmission is progressive at all time that may include irrelevant and insignificant data and information. Continuous types of wireless monitoring systems often pose problems of handling large-sized data that may deteriorate the performance of the system. The proposed method is to suggest an event-triggered monitoring system that captures and transmits relevant data only. An error signal generated by the Principal Components Analysis (PCA) is utilized as an index for event detection and selective data transmission. With this new monitoring scheme, the remote server is relieved of unwanted data by receiving only relevant information from the wireless sensor networks. The performance of the proposed scheme was verified with simulation studies.

모바일 P2P 네트워크에서 피어의 이동성을 고려한 연속적인 k-최근접 질의 처리 (Continuous K-Nearest Neighbor Query Processing Considering Peer Mobilities in Mobile P2P Networks)

  • 복경수;이현정;박용훈;유재수
    • 한국콘텐츠학회논문지
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    • 제12권8호
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    • pp.47-58
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    • 2012
  • 본 논문에서는 MP2P(Mobile Peer-to-Peer) 네트워크 환경에서 이동하는 피어들을 대상으로 실시간으로 질의 결과를 갱신하는 연속적인 k-최근접 질의 처리 기법을 제안한다. 제안하는 기법은 질의 피어와 근접한 k개의 피어를 효율적으로 모니터링하기 위하여 모니터링 영역(monitoring region)을 생성하여 배포한다. 모니터링 영역은 주변 피어들의 이동 벡터를 이용하여 특정 시간 범위 내에서 최소 k개의 질의 결과를 보장하기 위해 만들어진 영역이다. 제안하는 기법은 주변 피어들의 벡터를 이용하여 Monitoring Region을 계산하기 때문에 유지 시간을 증가시켜 모니터링 영역의 무효화에 따른 질의 재수행 비용을 감소시킨다. 제안하는 기법의 우수성을 입증하기 위해 기존 기법과 성능 평가를 수행한 결과 제안하는 기법이 기존 기법보다 우수한 성능을 보였다.

Rapid full-scale expansion joint monitoring using wireless hybrid sensor

  • Jang, Shinae;Dahal, Sushil;Li, Jingcheng
    • Smart Structures and Systems
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    • 제12권3_4호
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    • pp.415-426
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    • 2013
  • Condition assessment and monitoring of bridges is critical for safe passenger travel, public transportation, and efficient freight. In monitoring, displacement measurement capability is important to keep track of performance of bridge, in part or as whole. One of the most important parts of a bridge is the expansion joint, which accommodates continuous cyclic thermal expansion of the whole bridge. Though expansion joint is critical for bridge performance, its inspection and monitoring has not been considered significantly because the monitoring requires long-term data using cost intensive equipment. Recently, a wireless smart sensor network (WSSN) has drawn significant attention for transportation infrastructure monitoring because of its merits in low cost, easy installation, and versatile on-board computation capability. In this paper, a rapid wireless displacement monitoring system, wireless hybrid sensor (WHS), has been developed to monitor displacement of expansion joints of bridges. The WHS has been calibrated for both static and dynamic displacement measurement in laboratory environment, and deployed on an in-service highway bridge to demonstrate rapid expansion joint monitoring. The test-bed is a continuous steel girder bridge, the Founders Bridge, in East Hartford, Connecticut. Using the WHS system, the static and dynamic displacement of the expansion joint has been measured. The short-term displacement trend in terms of temperature is calculated. With the WHS system, approximately 6% of the time has been spent for installation, and 94% of time for the measurement showing strong potential of the developed system for rapid displacement monitoring.

Continuous Blood Pressure Monitoring using Pulse Wave Transit Time

  • Jeong, Gu-Young;Yu, Kee-Ho;Kim, Nam-Gyun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.834-837
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    • 2005
  • In this paper, we describe the method of non-invasive blood pressure measurement using pulse wave transit time(PWTT). PWTT is a new parameter involved with a vascular that can indicate the change of BP. PWTT is measured by continuous monitoring of ECG and pulse wave. No additional sensors or modules are required. In many cases, the change of PWTT correlates with the change of BP. We measure pulse wave using the photo plethysmograph(PPG) sensor in an earlobe and we measure ECG using the ECG monitoring device our made in the chest. The measurement device for detecting pulse wave consists of infrared LED for transmitted light illumination, pin photodiode as light detector, amplifier and filter. We composed 0.5Hz high pass, 60Hz notch and 10Hz low pass filter. ECG measurement device consists of multiplexer, amplifier, filter, micro-controller and RF module. After amplification and filtering, ECG signal and pulse wave is fed through micro-controller. We performed the initial work towards the development of ambulatory BP monitoring system using PWTT. An earlobe is suitable place to measure PPG signal without the restraint in daily work. From the results, we can know that the dependence of PWTT on BP is almost linear and it is possible to monitoring an individual BP continuously after the individual calibration.

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MEMS 가속도계 기반의 기계 상태감시용 스마트센서 개발 (Development of MEMS Accelerometer-based Smart Sensor for Machine Condition Monitoring)

  • 손종덕;심민찬;양보석
    • 한국소음진동공학회논문집
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    • 제18권8호
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    • pp.872-878
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    • 2008
  • Many industrial operations require continuous or nearly-continuous operation of machines, interruption of which can result in significant cost loss. The condition monitoring of these machines has received considerable attentions in recent years. Rapid developments in semiconductor, computing, and communication with a remote site have led to a new generation of sensor called "smart" sensors which are capable of wireless communication with a remote site. The purpose of this research is to develop a new type of smart sensor for on-line condition monitoring. This system is addressed to detect conditions that may lead to equipment failure when it is running. Moreover it will reduce condition monitoring expense using low cost MEMS accelerometer. This system is capable for signal preprocessing task and analog to digital converter which is controlled by CPU. This sensor communicates with a remote site PC using TCP/IP protocols. The developed sensor executes performance tests for data acquisition accuracy estimations.

연속 Top-k 질의 모니터링을 위한 효율적인 알고리즘 (An Efficient Algorithm for Monitoring Continuous Top-k Queries)

  • 장재희;정하림;김용희;김응모
    • 정보과학회 논문지
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    • 제43권5호
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    • pp.590-595
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    • 2016
  • 본 논문에서는 기존 공간 속성만을 고려하는 그리드 기반의 색인 기법을 변형하여 보다 빠른 연산을 수행하는 상위-k 질의 기법을 제안한다. 제안하는 기법은 이동 객체의 공간 속성 뿐만 아니라 비공간 속성을 활용하여 사용자가 선호하는 정보를 효과적으로 검색할 수 있는 메인메모리 기반 그리드 색인 구조인 Bit-Vector Grid Index(BVGI)를 구축한다. 그리드의 각 셀은 이동객체의 비공간 속성 값을 비트 벡터로 부호화하여 이동 객체가 어떤 셀에 포함되어 있는지 빠르게 판단할 수 있고, 각 셀에 존재하는 이동객체의 비트 벡터만을 비교하여 불필요한 연산을 줄일 수 있다. 성능 평가를 통해 제안하는 BVGI 기법이 기존의 질의 처리 기법보다 메모리 사용량과 CPU-time 측면에서 우수함을 보였다.

On-Line Monitoring of Low Biochemical Oxygen Demand Through Continuous Operation of a Mediator-Less Microbial Fuel Cell

  • MOON, HYUN-SOO;CHANG, IN-SEO;JANG, JAE-KYUNG;KIM, KYUNG-SHIK;LEE, JI-YOUNG;LOVITT, ROBERT W.;KIM, BYUNG-HONG
    • Journal of Microbiology and Biotechnology
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    • 제15권1호
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    • pp.192-196
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    • 2005
  • Abstract Oligotrophic microbial fuel cells (MFCs) were tested for the continuous monitoring of low biochemical oxygen demand (BOD) by using artificial wastewater, containing glucose and glutamate, as check solution. Ten times diluted trace mineral solution was used to minimize the background current level, which is generated from the oxidation of nitrilotriacetate used as a chelating agent. The feeding rate of 0.53 ml/min could increase the sensitivity from 0.16 to 0.43 ${\mu}$A/(mg BOD/l) at 0.15 ml/min. The dynamic linear range of the calibration curve was between 2.0 and 10.0 mg BOD/l, and the response time to the change of 2 mg BOD/l was about 60 min. The current signal from an oligotroph-type MFCs increased with the increase in salts concentration, and the salt effect could be eliminated by 50 mM phosphate buffer.