• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.492-496
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• 2002

We present the web-based remote monitoring system using distributed object technology. In order to provide the desired functionality, the system has used CORBA(Common Object Request Architecture) and Java Servlet to implement the integrated distributed object environment. It converts the existing standalone machine monitoring system into web-based machine monitoring system. It consists of applet program, CORBA server and CORBA client. The usefulness of our system will be illustrated by the application to ICM(Integrated Condition Monitoring) System developed by KIST Tribology Center.

• 정보처리학회논문지A
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• 제11A권3호
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• pp.181-188
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• 2004

인터넷 기반 분산/병렬 처리 시스템인 PDP(Parallel/Distributed Processing)는 인터넷의 유휴상태 호스트들을 이용하여 대용량 작업을 병렬로 처리해서 전체 수행 시간을 감소시킨다. 본 연구에서는 실시간 네트워크 모니터링을 활용하여 수시로 변화하는 네트워크 환경에 적응하여 병렬/분산 처리되는 방안을 제안한다. 실시간 네트워크 모니터링 정보를 PDP 주요 핵심 알고리즘들에 적용하여 네트워크 과부하 및 결함으로 발생하는 작업 지연 요소에 적응적으로 대처함으로써 전체 성능이 향상됨을 보인다.

• Structural Monitoring and Maintenance
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• 제7권1호
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• pp.1-12
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• 2020

Railway tracks are the direct supporting structures of the trains, which are vulnerable to produce large deformation under the temperature stress or subgrade settlement. The health status of track is critical, and the track should be routinely monitored to improve safety, lower the risk of excess deformation and provide reliable maintenance strategy. In this paper, the distributed optical fiber sensor was proposed to monitor the continuous deformation of the track. In order to validate the feasibility of the monitoring method, two deformation monitoring tests on one steel rail model in laboratory and on one real railway tack in outdoor were conducted respectively. In the model test, the working conditions of simply supported beam and continuous beam in the rail model under several concentrated loads were set to simulate different stress conditions of the real rail, respectively. In order to evaluate the monitoring accuracy, one distributed optical fiber sensor and one fiber Bragg grating (FBG) sensor were installed on the lower surface of the rail model, the strain measured by FBG sensor and the strain calculated from FEA were taken as measurement references. The model test results show that the strain measured by distributed optical fiber sensor has a good agreement with those measured by FBG sensor and FEA. In the outdoor test, the real track suffered from displacement and temperature loads. The distributed optical fiber sensor installed on the rail can monitor the corresponding strain and temperature with a good accuracy.

• Journal of Communications and Networks
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• 제11권4호
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• pp.350-358
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• 2009

In a wireless sensor network (WSN) setting, this paper presents a distributed decision-making framework and illustrates its application in an online structural health monitoring (SHM) system. The objective is to recover a damage severity vector, which identifies, localizes, and quantifies damages in a structure, via distributive and collaborative decision-making among wireless sensors. Observing the fact that damages are generally scarce in a structure, this paper develops a nonlinear 0-norm minimization formulation to recover the sparse damage severity vector, then relaxes it to a linear and distributively tractable one. An optimal algorithm based on the alternating direction method of multipliers (ADMM) and a heuristic distributed linear programming (DLP) algorithm are proposed to estimate the damage severity vector distributively. By limiting sensors to exchange information among neighboring sensors, the distributed decision-making algorithms reduce communication costs, thus alleviate the channel interference and prolong the network lifetime. Simulation results in monitoring a steel frame structure prove the effectiveness of the proposed algorithms.

• Structural Monitoring and Maintenance
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• 제1권2호
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• pp.173-182
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• 2014

We describe the application of a distributed optical fiber sensor based on stimulated Brillouin scattering, as an integrated system for safety monitoring of railway infrastructures. The strain distribution was measured statically and dynamically along 60 meters of rail track, as well as along a 3-m stone arch bridge. We show that, gluing an optical fiber along the rail track, traffic monitoring can be performed in order to identify the train passage over the instrumented sector and determine its running conditions. Furthermore, dynamic and static strain measurements on a rail bridge are reported, aimed to detect potential structural defects. The results indicate that distributed sensing technology represents a valuable tool in railway traffic and safety monitoring.

• 비파괴검사학회지
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• 제25권6호
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• pp.421-430
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• 2005

Brillouin time-domain analysis in optical fibres is a novel technique making possible a distributed measurement of temperature and strain over long distance and will deeply modify our view about monitoring large structures, such as dams, bridges, tunnels and pipelines, Optical fibre sensing will certainly be a decisive tool for securing dangerous installations and detecting environmental and industrial threats.

• 한국멀티미디어학회논문지
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• 제7권5호
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• pp.755-765
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• 2004

최근에 많은 유휴 상태의 호스트 자원들을 이용한 인터넷 기반 분산/병렬 컴퓨팅은 대용량 작업처리와 여러 중요 논제들에 대해 그 유용성이 증명되고 있다. 대용량 작업이 수행되는 동안, 작업에 참여하는 호스트의 성능과 상태 변화에 대처하기 위한 실시간 모니터링 기능이 요구된다. 본 연구에서는 글로벌 컴퓨팅 (global computing) 인트라스트럭처(infrastructure)로 구축된 인터넷 기반 분산/병렬 처리 프레임워크인 PDP(Parallel Distributed Processing)상의 실시간 모니터링 및 시각화에 대한 내용을 소개한다.

• KIEE International Transactions on Power Engineering
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• 제4A권4호
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• pp.214-220
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• 2004

Power quality monitoring is the cornerstone for power quality analysis, diagnosis and improvement. The measurement of power quality (PQ) evolves from instantaneous metering to continuous monitoring. Furthermore, recent technologies enable us to construct more flexible, reliable, rapid and economical power quality monitoring system (PQMS). Therefore, this paper presents an improved PQMS with a new distributed monitoring structure. The proposed PQMS consists of a PQ meter, PQ analyzer and GUI. The PQ meter only collects raw data and the PQ analyzer performs power quality analysis. It has several advantages compared to conventional structures in economic efficiency, modularity, speed, etc. PQ monitoring algorithms to catch steady-state trends and to detect PQ events are also adapted to the proposed structure. Using the proposed structure and monitoring algorithm, a prototype PQMS is constructed and real-time testing is performed.

• 센서학회지
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• 제32권3호
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• pp.199-206
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• 2023

This study presents a novel monitoring technique for underwater high-voltage direct current (HVDC) cables based on the Distributed Acoustic Sensor (DAS). The proposed technique utilizes vibration and acoustic signals generated on HVDC cables to monitor their condition and detect events such as earthquakes, shipments, tidal currents, and construction activities. To implement the monitoring system, a DAS based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) system was designed, fabricated, and validated for performance. For the HVDC cable monitoring experiments, a testbed was constructed on land, mimicking the cable burial method and protective equipment used underwater. Defined various scenarios that could cause cable damage and conducted experiments accordingly. The developed DAS system achieved a maximum measurement distance of 50 km, a distance measurement interval of 2 m, and a measurement repetition rate of 1 kHz. Extensive experiments conducted on HVDC cables and protective facilities demonstrated the practical potential of the DAS system for monitoring underwater and underground areas.

• 정보처리학회논문지D
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• 제13D권1호
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• pp.139-146
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• 2006

본 논문에서는 분산 트랜잭션 워크플로우 모니터링 시스템의 설계 및 구현에 관하여 기술한다. 워크플로우 인스턴스들의 실행 상태 관리를 주요 목적으로 하는 전통적인 워크플로우 시스템의 모니터링 기능은 워크플로우의 초대형화와 트랜잭션화를 특징으로 하는 분산형 트랜잭션 워크플로우 시스템에서는 워크플로우의 처리 상태 관리뿐만 아니라 구조적인 정보의 수집, 통계 정보 제공, 사용자들의 처리 상태 정보 등과 같은 다양한 부가적인 정보 처리 및 관리 기능을 제공하는 분산형 모니터링 서비스를 필요로 한다. 본 논문에서는 이러한 분산형 트랜잭션 워크플로우 시스템에서 필수적으로 요구되는 새로운 워크플로우 모니터링의 특징을 확장 정의하고, 이를 지원하는 점 기반의 분산 트랜잭션 워크플로우 모니터링 시스템의 상세 설계 및 이의 구현 방안을 소개한다.