• 한국멀티미디어학회논문지
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• 제11권7호
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• pp.1007-1015
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• 2008

제조공정 내의 센서 및 계장기기로 부터의 실시간 데이터를 웹 상에서 제공하기 위해 XML(eXtensible Markup Language)에 기반한 통신 서비스 모델을 제안하였다. HTML(Hyper Text Markup Language)은 웹상에 비실시간 멀티미디어 데이터를 표현하는 데는 적합하나 제조 공장에서 발생되는 실시간 데이터를 표현하는 데는 적합하지 못하다. 인트라넷 환경에서 프로세스 데이터의 XML 기반 웹 서비스 적용을 위해 시스템 설계 기준을 제공을 목적으로 통신 서비스의 실시간 성능에 대해 평가하였다. 데이터 표현을 위한 XML스키마를 제안하고 메시지 길이 증가로 인한 전송 지연과 원 데이터를 정의된 XML 표현으로 변환하는 과정에서 발생하는 처리 지연의 측면에서 시뮬레이션에 의해 성능을 평가하였다. 시뮬레이션에서 XML로의 변환 기능을 수행함에 있어 두 가지 형태의 구현 구조를 가정하였다. 하나는 데이터의 변환이 데이터가 계측기에서 SCC(Supervisory Control Computer)로 전송된 이후 SCC에서 수행되는 구조이고 다른 하나는 데이터가 SCC로 전송되기 전에 계측기에서 변환 과정이 수행되는 구조이다. 두 구조 각각에 대해 20%, 50%, 80%의 부하와 6종의 메시지 길이의 조건 각각을 변화시키면서 성능을 평가하였다. 실험 결과는 Ethernet 100BBaseT 네트워크에서 총 트래픽이 7 Mbps 이하인 시스템에서 적용이 가능함을 보여 주었다.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.233-241
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• 2018

최근 철도안전 감시 및 제어를 위한 데이터 분산 서비스 기반의 융합시스템인 실시간 철도안전 통합 감시 제어 시스템 개발 연구가 진행되고 있다. 차량, 신호, 전력 및 안전감시 설비의 안전 데이터를 실시간 수집하고, 대용량 데이터 처리를 위하여 분산 서비스 기반의 통신 미들웨어를 채택하였다. 그러나, 기존 관제 서버로 활용되는 서버장치의 경우 안전성 등의 사유로 하드웨어 성능이 낮아 분산 서비스 미들웨어의 최대 성능을 발휘하지 못하는 실정이다. 안전관제 시스템에서도 초당 20만 패킷을 전송량 목표로 설정하였으나 LAB 기반 성능시험을 수행한 결과 충족하지 못하였다. 본 논문에서는 기존 장비의 데이터 수집 성능을 개선하고자 철도 데이터의 특성을 분석하였고, 분석 결과에 따라 패킷량이 많은 신호설비와 차량설비의 데이터 모델에 DDS 기반의 스트리밍 전송방식을 적용하였다. 그 결과 하드웨어 성능이 동일한 경우 처리량이 기존보다 약 30.4배 향상됨을 확인하였다. 향후 실시간 철도안전 통합 감시 제어 시스템에 실제로 적용하여 데이터 처리의 성능을 개선해나갈 예정이다.

• 전기학회논문지
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• 제60권2호
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• pp.245-251
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• 2011

Quantities of data in the DMS (Distribution management system) or SCADA (Supervisory control and data acquisition) system is enormously large as illustrated by the usage of term flooding of data. This enormous quantity of data is transmitted to the status data or event data of the on-site apparatus in real-time. In addition, if GIS (Geographic information system) and AMR (Automatic meter reading), etc are integrated, the quantity of data to be processed in real-time increases unimaginably. Increase in the quantity of data due to addition of system or increase in the on-site facilities cannot be handled through the currently used Single Thread format of data processing technology. However, if Multi Thread technology that utilizes LF-POOL (Leader Follower -POOL) is applied in processing large quantity of data, large quantity of data can be processed in short period of time and the load on the server can be minimized. In this Study, the actual materialization and functions of LF POOL technology are examined.

• 제어로봇시스템학회논문지
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• 제14권2호
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• pp.184-190
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• 2008

This paper describes a message model based on XML (eXtensible Markup Language) to present real-time data from sensors and instruments at manufacturing processes for web service. HTML (Hyper Text Markup Language) is inadequate for describing real-time data from process control plants while it is suitable for displaying non-real-time multimedia data on web. For XML-based web service of process data, XML format for the data presentation was proposed after investigating data of various instruments at steel-making plants. Considering transmission delay inevitably caused from increased message length and processing delay from transformation of raw data into defined format, which was critical for operation of a real-time system, its performance was evaluated by simulation. In the simulation, we assumed two implementation models for conducting the transformation function. In one model, transformation was done at an SCC (Supervisory Control Computer) after receiving real-time data from instruments. In the other model, transformation had been carried out at instruments before the data were transmitted to the SCC. Various tests had been conducted under different conditions of offered loads and data lengths and their results were described.

• 한국태양에너지학회 논문집
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• 제40권3호
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• pp.1-20
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• 2020

In accordance with the Government's policy, renewable power generation is expanding very largely. This leads to increasing uncertainty in the power market and power system owing to the intermittent and fluctuating output characteristics of renewable power generators. Data on the acquisition of renewable power generators can be largely classified according to the operation of the power market and power system. Data on the settlement for the payment for the power amount are acquired in the power market, and real-time data for monitoring the status and output of the generators are acquired in the power system. However, renewable power generators operating in the power market have different acquisition cycles depending on the method of communication of the power meter. They acquire data only for settlement purposes and have no real-time data, which requires improvement. In this paper, the acquisition status is reviewed by classifying the data of renewable power generators into settlement and real-time data. In addition, measures and acquisition criteria for real-time data of renewable power generators for improving the acquisition method are proposed.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.92-95
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• 2019

Automation control and the data for control of industrial equipment for the diagnosis and prediction is a key to success in the 4th industrial revolution. It increases process efficiency and productivity through data collection, realtime monitoring, and the data analysis. However, university and research environment are still suffering from logging the data in manual way, and we occasionally loss the equipment data logging due to the lack of automatic data logging system. State variable presents the current condition of the equipment operation which is closely related to process result, and it is valuable to monitor and analyze the data for the equipment health monitoring. In this paper, we demonstrate the collection of equipment state variable data via programmable logic controller (PLC) and the visualization of the collected data over the Web access supervisory control and data acquisition (SCADA). Test vehicle for the implementation of the suggested SCADA system is a relay switched physical vapor deposition system in the university environment.

• Smart Structures and Systems
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• 제11권5호
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• pp.453-476
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• 2013

DuraMote is a remote sensing system developed for the "NIST TIP project: next generation SCADA for prevention and mitigation of water system infrastructure disaster". It is designed for supervisory control and data acquisition (SCADA) of ruptures in water pipes. Micro-electro mechanical (MEMS) accelerometers, which record the vibration of the pipe wall, are used detect the ruptures. However, the performance of Duramote cannot be verified directly on a water distribution system because it lacks an acceptable recordable level of ambient vibration. Instead, a long-span cable-stayed bridge is an ideal test-bed to validate the accuracy, the reliability, and the robustness of DuraMote because the bridge has an acceptable level of ambient vibration. The acceleration data recorded on the bridge were used to identify the modal properties of the structure and to verify the performance of DuraMote. During the test period, the bridge was subjected to heavy rain, wind, and a typhoon but the system demonstrates its robustness and durability.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1727-1731
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• 2003

In this paper we proposed backward fuzzy Petri-net to diagnoses faults in power systems by using the time sequence information of protection system. As the complexity of power systems increases, especially in the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires new and systematic methods to the reasoning process, which improves both its accuracy and its efficiency. The fuzzy Petri-net models of protection system are composed of the operating process of protective devices and the fault diagnosis process. Fault diagnosis model, which makes use of the nature of fuzzy Petri-net, is developed to overcome the drawbacks of methods that depend on operator knowledge. The proposed method can reduce processing time and increase accuracy when compared with the traditional methods. And also this method covers online processing of real-time data from SCADA (Supervisory Control and Data Acquisition)

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.291-293
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• 2007

SCADA (Supervisory Control and Data Acquisition) SCADA refers to the combination of telemetry and data acquisition [1]. SCADA system has been used for remote measurement and control on the critical infrastructures as well as modem industrial facilities. Electric Power system is a representative system using SCADA network for its communication. Integration between many networks and increasing threatens of terrorism have made the potential risk by cyber attacks real and bigger in power system. Recently, many researching efforts have been made on SCADA network for improving its security. In general aspect, there are already several ways to secure the system like encryption, firewall, authentication, etc. In this paper, we focus on symmetric encryption method and propose the proper key distribution method to reflect the unique characteristics of SCADA network communication.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.122-124
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• 2000

As the complexity of power systems increases, especially in the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires new and systematic methods to the reasoning process, which improves both its accuracy and its efficiency. Therefore this paper proposes a method of the modeling of protection systems and fault diagnosis in power systems using Fuzzy Petri Nets (FPN). The proposed method can reduce processing time and increase accuracy when compared with the traditional methods. And also this method can cover online processing of real-time data from SCADA (Supervisory Control and Data Acquisition).