• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.922-924
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• 1996

This paper presents the construction of Digital DAS system for supervising of power system simulator (KERISIM) which is developed in KERI. This system is composed of input transducer, input conditioner and digital supervisor. In order to watch P,Q,V,I, Power Factor and RMS in KERISIM successively, Digital arithmetic algorithm is accomplished to calculate Real/Reactive power from voltage/current data which is transferred by secondary part of CT/PT in simulator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1154-1163
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• 2008

DAS and SCADA system are main systems, which operate and manage the power system by using computer and communication technology. But DAS and SCADA have been operated independently in Korea, so there was some time delay in the fault handling and live-line work. To improve that problems, studies on the interface between DAS and SCADA have been needed. From November 2005 to December 2007, the pilot project has been performed in KEPCO's branch offices, as a result, direct method will be applied widely all over the country until 2010 because the operation information of substation users want can be transmitted fast and it is possible to control 43RC directly although the expense for direct method is about 1.3 times larger than that for web method. To improve problems revealed during the pilot project, substation object to object communication method is proposed and interface database automatic generation and interface system diagnosis and logging functions are developed. Interface data point and communication data type are defined, substation single line diagram automatic generation or manual editing function, SCADA monitoring and controlling function, log data managing function are developed in SCADA HMI program. It is expecting to reduce the average time for each outage about 33% and to improve the reliability, efficiency of operation, execution of DAS from automatic load transfer under a fault, and to contribute to export project.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.3
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• pp.168-174
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• 2004

On-line monitoring system(OMS) has been developed for the pumped storage generator/motor The OMS is applied to diagnosis of the PD(partial discharge) activity of stator insulation, the shorted-turn of rotor winding and the variation of the air-gap between stator and rotor. The OMS consists of DAS(data acquisition system), main server system, gateway and display PC. The DAS measures the PD, the shorted-turn and air-gap from three sensors installed on the generator/motor. The gateway controls the data which sent by DAS. The main server system saves the data, analyzes the data and conducts the diagnostic algorithm. The display PC shows the diagnostic results of partial discharge, shorted-turn and air-gap. Field tests were conducted using PDA(partial discharge analyzer). The results of the OMS and PDA measurements can be directly correlated with normalized quantity number(NQN), PD magnitude(Qm) and PD pattern.

• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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• pp.37-41
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• 2012

High-efficiency and low-noise axial flow fan is developed by combining the FanDAS, a computerized axial fan design/performance analysis system, and CFD software(CFX). Based on fan design requirements, FanDAS conducts 3-D blade geometry design, quasi-3D flow/ performance analyses and noise evaluation by using through-flow analysis method and noise models for discrete frequency and broadband noise sources. Through the parametric studies of fan design variables using FandDAS, preliminary and baseline design is achieved for high efficiency and low noise fan, and then can be coupled with a CFD technique such as the CFX code for constructing final and optimized fan design. The FanDAS-CFX coupled system and its design procedure are applied to actual fan development practice. The FanDAS provides an optimized 3-D fan blade geometry, and its predictions on the performance and the noise level of designed fan are well agreed with actual test results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.126-133
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• 2008

Computer and communication of based IT technology use to das that remote control, monitoring, measuring automatic gas switch, recloser located far about $20{\sim}30[km]$. For increasing efficiency billing, metering of high voltage customer use to amr system. If between das and amr interface operate when generated fault in high voltage electric equipment of customer part, amr system serve to das quickly in fault information data, correct fault location.

• Journal of Sensor Science and Technology
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• v.32 no.3
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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.

• Publications of The Korean Astronomical Society
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• v.22 no.3
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• pp.63-73
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• 2007

In this paper, we introduce the performance test results of digital data processing system for KVN (Korean VLBI Network). The digital data processing system for KVN consists of DAS (Data Acquisition System) and high-speed recorder which called Mark5B system. DAS system performs the digitalization of analog radio signal through ADS-1000 gigabit sampler with 1 Gsps/2-bit and process the digital filtering of digital signal. Mark5B system records the output data of DFB (Digital Filter Bank) with about 1 Gbps. In this paper, we carried out the preliminary evaluation experiments of the KVN digital data processing system connected between DAS system and Mark5B with VSI (VLBI Standard Interface) interface which is designed for compatible in each VLBI system. We first performed all of the KVN digital data processing system connected by VSI interface in the world. In factory inspection phase, we found that the DAS system has a memory read/write error in DSM (Digital Spectrometer) by analyzing the recorded data in Mark5B system. We confirmed that the DSM memory error has been correctly solved by comparing DSM results with Mark5B results. The effectiveness of KVN digital data processing system has been verified through the preliminary experiments such as data transmission, recording with VSI interface connection and data analysis between DSM and Mark5B system. In future work, we will perform the real astronomical observation by using the KVN 21m radio telescopes so as to verify its stability and performance.

• Proceedings of the KIEE Conference
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• summer
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• pp.572-574
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• 2004

The configuration of Distribution Automatic System(BAS) is dual servers and raid 5(redundant arrays of inexpensive disks) clustering dual HDD. The DAS has the distributed object-oriented architecture using middleware software(BASEstar), so the number of client nodes has no limitation. Because the DAS is scalable, it can be configured using various application programs and be upgraded easily. The DAS has competitive to export because there are system development and accumulation of technology that coincide in International Standard, using common 05 and DB. This paper describes the structure of DAS hardware and software separately and proposes to improve program to share real time DB efficiently at each node.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2399-2401
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• 1998

For a medium/small scale DAS, which using the PCS network as the system communication network, we developed the scheme of communication protocol of DAS between master and remote terminal. This paper presents advanced protocol which has basic frame format and data flow for the medium/small scale DAS, and the procedure of the developing sequence.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.2
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• pp.69-76
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• 2005

This study for Customer Satisfaction(Customer Focus) by Profit security' in the field Process improvement activity and man-power upgrade by DAS(DATA Acquisition System) in the Plant that is fusion Off Line and On Line(IT), Especially the basic of the most foundation in the beginning Step of Toyota system is 3-jeong(a standard instrument; right volume, right box, right position), 5S(Seiri, Seiton, Seisoh, Seiketsu, Sitsuke ; KAISEN, KANBNA System(for Logistic), Further more KPC has established the digital environment such as CIM ; Computer Integrated Manufacturing), IMS ; Intelligent Manufacturing System ERP ; Enterprise Resource Planning, DAS; Data Acquisition System, Autonomous QC & SPC etc,.) in order to realize the intelligent informatization, which is core base for obtaining the competitive power and for responding to the various 21C management environment in flexibility. In this digital management environment, continuously and powerfully they would advance for becoming the best of the world. For strategic changes to take place in industry 3 key important factors need to be included ; Integration of tasks function and process, Decentralization of information, Responsibility, Finally simplification of products and product structures.