• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1C
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• pp.28-36
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• 2011

As Power Line has been already installed over 60% of a residential area all over the world, Broadband Service has been possible using high-speed PLC(Power Line Communication) without new access line installed for Internet access. Because of such reason, PLC is researched as the most suitable service for Last Mile Solution. But, Power Line is designed for transmitting electric power, so peripheral Wireless Communication System is affected by a leak of electric wave. In this paper, we propose a High Performance Notch Filter algorithm in comparison with a existing notch filter for reduction of interference between existing Wireless Communication Service and Power Line Service. In addition, we implement the Notch Filter emulator appling a High Performance Notch Filter and using a embedded board.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.125-130
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• 2017

Since field control equipment such as PLC has no function to log key event information in the log, it is difficult to analyze the accident. Therefore, it is necessary to secure information that can analyze when a cyber accident occurs by logging the main event information of the field control equipment such as PLC and IED. The protocol analyzer is required to analyze the field control device (the embedded device) communication protocol for event logging. However, the conventional analyzer, such as Wireshark is difficult to process the data identification and extraction of the large variety of protocols for event logging is difficult analysis of the payload data based and classification. In this paper, we developed a system for Big Data based on field control device communication protocol payload data extraction for event logging of large studies.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.336-341
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• 2016

This paper presents an implementation of a communication network in wind turbines, which exploits the power-line communication system (PLC). We used an inductive coupling unit and a multi-interface device to connect a data-communication terminal to the power line, to ensure that stable communication was possible at various electric current and voltage values of the generator. The results of the operation tests conducted on an operational wind turbine showed that the implemented PLC demonstrated a transmission rate of at least 43 Mbps with a 100% success rate. Moreover, a real-time image was transmitted. Thus, the system could be a useful alternative for implementing a communication network in wind turbines that does not require additional channels. Since the presented system is easy to implement, and can support various interfaces for data communication, it will be quite useful when a real-time monitoring system is launched in wind turbines.

• The Journal of Information Technology
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• v.7 no.3
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• pp.37-45
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• 2004

The representative communication method which is applied in the low-speed power line communication modem with 60bps is single carrier method. It has been used mainly for the control. The single carrier method is very sensitive to a power line communication channel environment. Specially, the severe attenuation of the transmission signal according to the notch characteristics of channel becomes the main cause of communication error. Domestic power line channel environment has this notable feature. In this paper, we implemented the low-speed power line communication system which used the chirp signal method to be strong in notch and noise characteristics. In this research, we proposed the method which transmits 1- '1 Unit symbol Chirp signal' with a 100${\mu}s$ time within 1ms for 1 bit. Also it applied for the Convolution code for an error correction and the Manchester code for a collision perception and an error detection. It used the method which uses the bit correlator for signal detection in the receiver parts. We confirmed that the communication method of the chirp method has a excellent performance compared to single carrier methods with a result of experiment of the low-speed power line communication system with the 60bps.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1255-1260
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• 2011

In this paper, we study on the reliability of Very High-rate Power Line Communication (VH-PLC) for Smart Grid, so that the resultant data rate is over 400Mbps at a physical layer. Firstly, reviewing the research trend of the PLC, we discuss the required techniques for supporting the Smart Grid. Considering a pre-specification with the value of several parameters, we investigate a multi-carrier modulation technique to overcome limitations of higher rate transmission under power line channel environments. Then, we propose a system specification of the VH-PLC in the sense of enhancing two features. One is resolving the problem of the co-existence of the deployed high-speed PLC according to the published standardization of KS X 4600-1 in Korea. The other is getting better performance on the grid adopting the diverse element techniques, such as multi-carrier modulation, a subcarrier utilization mode, a variable rate LDPC (Low Density Parity Check) code, and a time and frequency diversity technique. Further, a simulation tool, composed of an Event-Driven simulator and a Time-Driven simulator, is developed for the purpose of verifying the system performance and continuously cross-checking the test bench signal of the proposed VH-PLC system.

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.1-17
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• 2015

A river water level monitoring system which prevents salt water damages and effectively excludes floods has been developed to contribute efficient operation of Nakdong river estuary barrage. The system can be used for monitoring upstream conditions more quickly and do appropriate responses over changes. Telemetry and telecontrols using PLCs have been built at the three sites that directly influence on the operation of barrage gates, and are linked to Nakdong river estuary barrage's IOS (Integrated Operation System) through public communication networks. By using PLC, the system can achieve even higher reliability and versatility than before as well as easy management. By power control devices, we can remotely control the power of PLCs to treat the minor troubles instantly without going on-sites. The power control devices also save data in preparation for the cases of communication failures. The system uses ADSL (FTTH) as a main network between SCADA server and PLCs, and CDMA (M2M) as a secondary network. In order to compensate security vulnerabilities of public communication network, we have installed the VPNs for secure communication between center and the observation stations, just like a dedicated network. Generally, river water level observations have been used custom-manufactured remote terminals to suit their special goals. However, in this case, we have established a system with open architecture considering the interface between different systems, the ease of use and maintenance, security, price, etc.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.4
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• pp.91-97
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• 2005

As the developing of industry, the nonlinear equipments as inverter, converter, SMPS(Switching Mode Power Supply) and motor have been increased. But the sensitive electronic loads to the power quality, such as computers and other electronic equipments, have been spreaded out very fast. Thus, the power quality(PQ) problems and the real time power quality monitering(PQM) are one of the important issues in industry and building area for the intelligent control of the systems. One of them, PQM using PLC(Power Line Communication) have good merits that can send and receive the PQ information without any new network line. This paper presents the PQM hardware and software to monitor the PQ information by using PLC that meets the categories of IEEE Std. 1159.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.782-787
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• 2014

Due to the complicated steel structure and safety concern, it is very difficult to deploy wireless networks in power plants. This paper presents a hybrid network, named as $P^2HYMN$ (Power Plant HYbrid Maintenance Network), encompassing PLC (Power Line Communication), TLC (Telephone Line Communication), and Wireless LAN. The design goal of $P^2HYMN$ is to integrate multimedia data such as design drawings of control equipment, process data, and video image data for maintenance operation in electric power plants. A Multiplex Line Communication (MLC) device was designed and implemented to integrate PLC, TLC, and Wireless LAN into $P^2HYMN$. Performance test of $P^2HYMN$ has been conducted on a testbed under various conditions. The throughput of TLC was shown as 39 Mbps. Because the bandwidth requirement per camera is 8.5 Mbps on average, TLC is expected to support more thant four video camera at the same time.

• The Journal of Information Technology
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• v.6 no.4
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• pp.1-9
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• 2003

This paper is about power line communication(PLC) over the low power voltage grid. The main advantage with power line communication is the use of an existing infrastructure. The PLC channel can be modeled as having multi-path propagation with frequency-selective fading, typical power lines exhibit signal attenuation increasing with length and frequency. OFDM(Orthogonal Frequency Division Multiplexing) is a modulation technique where multiple low data rate carriers are combined by a transmitter to form a composite high data rate transmission. The performance in consideration of the multi-path(echoes) powerline scheme is analyzed and verified by computer simulation.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.345-352
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• 2004

Currently, high data rate PLC(Power Line Communications), up to 100 Mbps, which use frequency bandwidth between 2 MHz and 30 MHz is investigated very hard, and commercial PLC modem for low voltage powerline network (indoor) is coming soon into communication market. For the purpose of developing a fit communication system which has little distortion of signal and attenuation, it is surely necessary to know about channel environments of powerline. Especially, the impedance measurement of the powerline and impedance matching are very important. As is known, since medium-voltage powerline (22.9 ㎸) is still working, it is not so simple to measure the powerline impedance. In our study, a portable impedance measurement equipment is developed. It consists of coupling capacitor, a drain coil and impedance matching transformer. The equipment is easily connected to medium voltage line and impedance of power line is measured using a network analyzer. Also, measurement results are used for impedance matching of PLC signal. In fact, matching transformer with several different impedances are used. The matching transformer is connected between coupling capacitor and signal port. In this paper, the developed portable impedance measurement equipment and impedance measurement results are presented. Also impedance matching technique using matching transformers will be explained. We showed the result of the improved performance by the impedance matching.