• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.51-52
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• 2013

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1990.10a
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• pp.105-110
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• 1990

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.877-887
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• 2015

In this paper, a design of communication joint tools to implement a legacy-line communication (LLC) system, which exploits various conductive lines in a train, is presented. We develop two kinds of joint tools; one is a conductive joint tool (CJT) that is connected directly to the conventional lines and the other is the inductive joint tool (IJT) which connects the conventional lines indirectly using electromagnetic induction. As a result, the practical experiment of data communication confirms that an LLC system with the developed joint tools has a transmission rate more than 20 Mbps in the distance of 200 m away. In addition, an environmental durability test shows that the joint tools operate stably in an extreme environmenal variation. It is, therefore, considered that the developed joint tools are very useful to implement a communication network in the train working currently.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.111-119
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• 2015

Smart Grid is a next-generation intelligent grid to optimize energy efficiency by integrating information and communication technologies to the existing power grid as a two-way exchange of information. HPGP communication standard for smart grid implementation has been developed for the emerging smart energy, home automation, electric vehicle communications applications. HPGP communication standard has the advantage of reducing cost and power consumption. Also, it can be interoperated with the previous HPAV communication standard. For the introduction of a new communication standard, the analysis of the reliability and interoperability verification is required. In this paper, we present sniffer test method as reliability test method about power line communication between PEV(Plug-in Electric Vehicle) and EVSE(Electric Vehicle Supply Equipment). Power line communication between PEV and EVSE is one of the most important Smart Gird applications. Also, we analyzed sniffer test results about power line communication based on HPGP between PEV and EVSE by using QCA7000 device, AVitar and Tool kit.

• 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.

• Smart Media Journal
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• v.4 no.2
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• pp.46-54
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• 2015

Communication between ECUs (Electronic Control Units) in agricultural machineries tends to use IS011783 widely, that is PGN (Parameter Group Number) based communication protocol lays on CAN protocol by altering its identifier part. Messages in line are transferred and received between ECUs according to ISO11783 standard. This paper discusses about design of wireless monitoring system. We used an ARM Cortex-M3 microcontroller embedded development board and marvel8686 wireless module. The wireless ISOBUS monitoring system, attached to communication line, reads messages, interpret them, and display them on the screen in easily comprehendible form. It can be used to generate messages and monitor the traffic on physical bus systems. The monitoring system connected to ECUs, monitor and simulate real traffic of communication and functionality of the ECUs. In order to support our work, we have implemented the monitoring tool. The development consists of two parts: GUI of the application and firmware level programming. Hence the monitoring system is attached to the communication line and equipped by Wi-Fi module; farmer/dispatcher in a farm monitors all messages in communication line on personal computer and smart device.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.43-47
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• 2021

This paper investigates the network throughput of PLC (Power Line Communication) system in the in-building network. The OFDM (Orthogonal Frequency Division Multiplexing) modulation format and adaptive bit loading algorithm is used to minimize the effect of signal loss and noise on transmission performance in the power line channel characterized by frequency selective fading. The network throughput of the PLC system which consists of gateway and CPE（Customer Premise Equipment) PLC modem in the in-building network is measured by network performance measurement tool, iperf and analyzed according to the TCP (Transmission Control Protocol) window size.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.19-23
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• 2010

This study is to develop power line communication and short-range wireless communication system using LED. I will create optical receiver and transmitter using LED and optical sensor and connectors for display device and communication in receiver and transmitter were created. Experiment method is to signal and waveform through oscilloscope date from optical sensor after chosen a highly efficient LED. In addition, reception and transmitter of smoothly data using visible light communication program were checked. I will compliment problems through this experiment and constantly study, improve on power loss.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.1
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• pp.56-60
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• 2005

In the power-line communication(PLC) systems, the power line is a wired medium. However, the power line channel has the multi-path fading characteristics like the wireless channel in the wireless communication systems because it has the signal reflection and divergence by the impedance mismatching between many branch lines and loads. So the analysis of the multi-path characteristics is very important, and it has been doing by the several measurement methods for the impulse response between the transmitter and the receiver. PN sequence method has originally been used as a wideband impulse response measurement mettled for wireless channel, but it is recently being applied to not only the wireless channel but also the wired channel like the power line channel. This method is more useful and effective for the long distance communication channel like the medium voltage power distribution line with the multi-paths[1]. In this thesis, we have measured impulse response for the medium voltage power distribution line channel by the wideband measurement method using PN sequence, analytically studied the measured data and presented the results.

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.202-207
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• 2013

In this paper, a high dividing ratio unequal power divider using parallel connection transmission line is presented. Because a very low impedance transmission line can't implement a microstrip technology, this can fabricate a parallel connection transmission line with high impedance. When we design a high dividing ratio divider, we need the very low impedance line. The parallel connection transmission line could be implemented to obtain a low impedance line characteristic. To validity this approach, we are implemented a 10:1 unequal divider at center frequency 1 GHz. The performances of power divider agree with simulation results.