• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1155-1160
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• 2011

The importance of broadband wireless communication implemented at subway tunnels is growing up. At 18GHz wireless video transmission system, the transmitter requires a digital modulation method. At subway tunnel, A 18GHz's influence of the multi-pass padding is strong. OFDM digital modulation that is strong for multi-pass padding is recommended. Duplexing methode uses FDD to transmit and receive broadband data at the same time. In the case of FDD we assign a private use channel each with the transmission at the receiving. In this paper, We implement multiple access wireless OFDM transceiver. We verified that one ground transceiver communicates with two car transceiver at the same time.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1008-1013
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• 2011

The importance of broadband wireless communication system at subway tunnels is growing up. At 18GHz wireless video transmission system, the transmitter requires a digital modulation method. At subway tunnel, A 18GHz's influence of the multi-pass padding is strong. OFDM digital modulation that is strong for multi-pass padding is recommended. Duplexing methode uses FDD to transmit and receive broadband data at the same time. In the case of FDD we assign a private use channel each with the transmission at the receiving. In this paper, We implement multiple access wireless OFDM transceiver. We verified that one ground transceiver communicates with two car transceiver at the same time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.1014-1019
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• 2013

Signal processing techniques based on fractional order calculus have been successfully applied in analyzing heavy-tailed non-Gaussian signals. It was found that the surface EMG signals from the muscles having nuero-muscular disease are best modeled by using the heavy-tailed non-gaussian random processes. In this regard, this paper describes an application of digital fractional order lowpass differentiators(FOLPD, weighted FOLPD) based on the fractional order calculus in detecting peaks of surface EMG signal. The performances of the FOLPD and WFOLPD are analyzed based on different filter length and varying MUAP wave shape from recorded and simulated surface EMG signals. As a results, the WFOLPD showed better SNR improving factors than the existing WLPD and to be more robust under the various surface EMG signals.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1951-1958
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• 2011

The objective of this study is to analyze the performance of digital low-pass differentiators(LPD) and then to provide a method to select effective LPD filter, for detecting spikes of surface motor unit action potentials(MUAP). The successful spike detection of MUAPs is a first important step for EMG signal decomposition. The performances of simple and weighted LPD(SLPD and WLPD) filters are analyzed based on different filter lengths and varying MUAPs from simulated surface EMG signals. The SNR improving coefficient and effective MUAP duration range from the analysis results can be used to select proper LPD filters under the varying conditions of surface EMG.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.174-176
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• 2000

In this paper, a high speed distance relay, using a digital signal processor(DSP) is presented. The idea of the protective algorithm is based on the least square method using minimum data window to minimize the relay operating time. A new disign concept for a low-pass filter is proposed. This analog low pass filter has minimum transient response time. The main processor of the relay is TMS320C31. According to a series of real time tests, the proposed protective relay shows reliable and fast operating characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.25-25
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• 2010

This paper describes the design and fabrication of a Risk Voltage Meter (RVM) which can analyze the step and touch voltages in grounding systems. The meter consists of a sine-wave power source which generates up to 300 [$V_{rms}$] in ranges of 45 [Hz]~1 [kHz], a 8 Ch. data acquisition module, and a personal computer. Also, a noise elimination method by a digital band-pass filter during measurement is proposed.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2089-2094
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• 2010

The importance of broadband wireless communication implemented at subway tunnels is growing up. At 18GHz wireless video transmission system, the transmitter requires a digital modulation method. At subway tunnel, A 18GHz's influence of the multi-pass padding is strong. OFDM digital modulation that is strong for multi-pass padding is recommended. In this paper, Suitable to a subway wireless video transmission OFDM receiver is designed. OFDM receiver system has 6dB gaion because uses diversity of space diversity and MRC(Maximum Ratio Combining) diversity. The transmitter system use C&ITechnologies's transmitter board. IF frequency of receiver is 480MHz. OFDM modulation parameter is as follow, The bandwidth is 8MHz, The numuber of carrier if 2,000, The modulation methode is QAM16, The guard interval is 1/32.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.1
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• pp.45-50
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• 1999

This paper describes a partial discharge (PD) on-line monitoring system used for large turbine generators. The system consists of a broadband current transducer, a computer-aid PD measurement system. By using a programmable fabricate band pass filter and an adaptive digital filter, the system can suppress the noise and extract PD signal from the intense noise surroundings successfully. Two simulated PD sources, which often exist in the large generators, were simulated and detected. At the end of this paper, some field test results, obtained from a 200MW generating set, were presented and discussed.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.8
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• pp.893-901
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• 1992

In this paper, we propose a new resolver-to digital(R/D) conversion method, in which a bang-bang type phase comparator is employed for fast tracking. We eliminate from the R/D conversion loop the low-pass filter which is needed to reject carrier signal and noise. Instead, we employ two prefilters outside the R/D conversion loop that take the role of the low-pass filter. Thereby, we can construct a fast and accurate tracking R/D converter. Some simulation and experimental results as well as mathematical performance analysis are presented to demonstrate the superior tracking performance of our R/D converter over conventional tracking R/D converters.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.224-226
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• 1993

Multi-layered neural networks offer an exciting alternative for modelling complex non-liner systems. This paper investigates the identification of continuous time nonliner system using neural networks with a single hidden layer. The digital low - pass filter are introduced to avoid direct approximation of system derivatives from sampled data. Using a pre-designed digital low pass filter, an approximated discrete-time estimation model is constructed easily. A continuous approximation liner model is first estimated from sampled input-out signals. Then the modeling error due to the nonlinearity is decreased by a compensator using neural network. Simulation results are given to demonstrate the effective of the proposed method.