• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1983-1984
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• 2008

뇌 활동의 전기적 신호인 뇌파(EEG)와 외부 자극에 대한 유발 전위(EP)를 측정하여 실시간으로 뇌지형도를 생성하는 real-time brain mapping system을 개발하였다. 측정 전극은 32채널을 사용하였고, EEG를 실시간 및 누적 주파수 분석을 통한 뇌파의 활성도 진단, EP를 측정하여 시각적/청각적 자극에 의한 유발 전위 분석을 할 수 있다. 본 시스템은 측정 대상군의 통계적 분석을 위한 Database를 구축하였고, 신뢰성 높은 뇌파 및 유발 전위 신호를 위하여 실시간 측정과정 및 측정 후 Data 검토과정에서 다양한 Artifact 제거 알고리즘이 도입되었다. 또한, 32 채널 Brain map을 구성하여 뇌파를 공간적으로 분석 가능하며, 시간 및 주파수의 증가에 따라 Brain map을 동영상화하여 시간적/주파수적 변화에 따른 분석이 가능하다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.334-337
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• 2005

The speech intelligibility is one of the most important factors in communication system. The speech intelligibility is related with speech to noise ratio. To enhance the speech to noise ratio, background noise reduction techniques are being developed. As a part of solution to noise reduction, this paper introduces directional microphone using beamforming method and speech filtering method. The directional microphone narrows the spatial range of processing signal into the direction of the target speech signal. The noise signal located in the same direction with speech still remains in the processing signal. To sort this mixed signal into speech and noise, as a following step, a speech-filtering method is applied to pick up only the speech signal from the processed signal. The speech filtering method is based on the characteristics of speech signal itself. The combined directional microphone and speech filtering method gives enhanced performance to speech intelligibility in communication system.

• Journal of the Institute of Convergence Signal Processing
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• v.1 no.2
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• pp.131-137
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• 2000

In this paper, as a compatible software radio transmission system, Digital-Radio conversion system which can directly change the digital signal generated by the logic circuit into radio signal is proposed. By the vector synthesis method, the digital signals can change directly into radio signal. If such a circuit is realized, RF circuit and an antenna can be composed by the simple one device, and the radio is directly controlled and performed by the software processing which is the essence of software radio. This Digital-Radio conversion system of this paper give many number of communication channels being offered by PN code and offer a hardware design flexibility by digitization, therefore it decrease the percentage ratio of hardware of system and give a more flexible function of software basis. In this paper, the principle of digital to radio signal generation algorithm is explained and the performance characteristics of proposed algorithm is shown in time base by the computer simulation method.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.6
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• pp.289-296
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• 2018

Drone detection in FMCW radar system needs complex techniques because a drone beat frequency is highly dynamic and unpredictable. Therefore, the current static signal processing algorithms cannot show appropriate detection accuracy. With dynamic signal fluctuation and environmental clutters, it can fail to detect a drone or make false detection. It affects to the radar system integrity and safety. Constant false alarm rate (CFAR), one of famous static signal process algorithm is effective for static environment. But for drone detection, it shows low detection accuracy. In this paper, we suggest neural network based FMCW radar system for detecting a drone. We use recurrent neural network (RNN) because it is the effective neural network for signal processing. In our FMCW radar system, one transmitter emits FMCW signal and four-way fixed receivers detect reflected drone beat frequency. The coordinate of the drone can be calculated with four receivers information by triangulation. Therefore, RNN only learns and inferences reflected drone beat frequency. It helps higher learning and detection accuracy. With several drone flight experiments, RNN shows false detection rate and detection accuracy as 21.1% and 96.4%, respectively.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.396-403
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• 2000

A thermal imaging system is implemented for the measurement and the analysis of the thermal distribution of the target objects. The main part of the system is a thermal camera in which a focal plane array typed sensor is introduced. The sensor detects the mid-range infrared spectrum of target objects and then it outputs a generic video signal which should be processed to form a frame thermal image. Here, a digital signal processor(DSP) is applied for the high speed processing of the sensor signals. The DSP controls analog-to-digital converter, performs correction algorithms and outputs the frame thermal data to frame buffers. With the frame buffers can be generated a NTSC signal and transferred the frame data to personal computer(PC) for the analysis and a monitoring of the thermal scenes. By performing the signal processing functions in the DSP the overall system achieves a simple configuration. Several experimental results indicate the performance of the overall system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.883-886
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• 2005

This paper proposed a wireless measurement system (WMS) for an effective condition monitoring using wireless communication. WMS consists of two parts: transmitter(TM) acquired a dynamic signal from physical system using ICP type accelerometer sensor. An acquired signal modulated through the low/high pass filter and amplifier in DAQ board, which converted to digital signal. Embedded board(E-board) transferred digital signals to base station(BS) through the socket IEEE.802.11.b. BS is adopted IOCP server structure. Because it can acquired signal well during transferred digital signal. Signal processing used LabVIEW Library, BS(server) designed to realize multi-thread using visual C++.NET for 1 many meaning data processing

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.173-180
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• 2006

An airborne radar is an essential aviation electronic system of the aircraft to perform various missions in all weather environments. This paper presents the design, development, and test results of the multi-mode pulsed Doppler radar system test model for helicopter-borne flight test. This radar system consists of 4 LRU units, which include ANTU(Antenna Unit), TRU(Tx Rx Unit), RSDU(Radar Signal & Data Processing Unit) and DISU(Display Unit). The developed technologies include the TACCAR processor, planar array antenna, TWTA transmitter, coherent I/Q detector, digital pulse compression, DSP based Doppler FFT filtering, adaptive CFAR, IMU, and tracking capability. The design performance of the developed radar system is verified through various helicopter-borne field tests including MTD (Moving Target Detector) capability for the Doppler compensation due to the moving platform motion.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.6
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• pp.119-127
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• 1996

The proposed method uses a signal of the smae frequency as the input modulating carrier frequency and of a different phase. This signal is generated in the digital automatic frequency control part to decide the input color demodulated signal. And the phase error from the burst signal is calculated. The calculated phase error is utilized to rmove the phase error contained inthe demodulated color signal. In this paper, digital signal processing of automatic color control is proposed for VCR system campatible with both NTSC and PAL TV systems.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.17-20
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• 2000

In a digital communication system, the transmission channel may introduce error into the digital signal being transmitted. It would be useful if a process could be devised so that the error could be removed in order to recover the transmitted digital signal. We design a corrective filter that is inverse filter, which will generate an output signal identical to the input signal. in order for two systems connected in cascade to produce an output which is identical to the input signal, the over-all unit sample response of the cascade connection must be a unit sample function.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.829-833
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• 1992

This paper presents the design of an automated EEG analyzing system. The design considerations including processing speed, A/D conversion, filtering, and waveforms detection, are overviewed with the description of the associated EEG characteristics. The architecture of the currently implemented system consists of a p-controller based front-end signal processing unit and a host computer system. The data acquisition procedures are described along with a couple of illustrations of the acquired EEG/EOG signal.