• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.65-68
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• 2000

In CDMA, the currently used PN code acquisition methods detect the phase of the incoming PN signal on the basis of ML estimation. In serial search strategy, it takes relatively long time for PN code acquisition. A study related to reduce processing time of PN code acquisition is important. Therefore we propose a reference code design for a new algorithm that a reference code and the received PN code are fully correlated to detect the transmitted PN code, in detail, the relative phase offset j of c⒡. After choosing two weight factors, we show the mathematical analysis and derivation for the reference code design.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.29-32
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• 2003

Recently, the development of diagnosis technique with high confidence is important on power equipment, for this reason is to use for measurement and analysis of PD with prior appearance of insulation breakdown In this paper, we presents the analysis of trouble signal to use both method of general analysis of $\Phi$-Q-N in PD and statistical parameter by this interpretation Equipment of simulation has made independently DS for 170kV GIS of one phase with same on field. The detected signal through the sensor of Induction and Acoustic Emission is classified which used to characteristic neural network algorithm and then it is analysis.

• 전력전자학회논문지
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• 제11권1호
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• pp.38-45
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• 2006

본 논문은 유도기의 정밀위치제어를 얻고자 외란 변화에 대하여 정밀위치 제어를 할 수 있는 외란 관측기를 적용하였다. 제안된 알고리즘은 외란 변화에 대한 유도전동기의 정밀 제어에 강인함을 보이고 있다. 모든 게인의 튜닝은 디지털 제어 이론에 입각하여 이산 영역에서 구하였다. 또 시뮬레이션은 시뮬링크를 사용하여 그 구성을 매우 간편하게 하였다. DS1102 보드를 이용한 유도기 정밀위치 제어 결과는 제안된 시스템의 유용성을 보인다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1998년도 학술발표대회 논문집 제17권 1호
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• pp.357-360
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• 1998

DS/CDMA system rejected narrow-band interference and additional White Gaussian noise which are occured at multipath, intentional jammer and multiuser to share same bandwidth in mobile communication systems. Because of having not sufficiently obtained processing gain which is related to system performance, they were not effectively suppressed. In this paper, an matched filter channel model using backpropagation neural network based on complex multilayer perceptron is presented for suppressing interference of narrow-band of direct sequence spread spectrum receiver in DS/CDMA mobile communication systems. Recursive least square backpropagation algorithm with backpropagation error is used for fast convergence and better performance in matched filter receiver scheme. According to signal noise ratio and transmission power ratio, computer simulation results show that bit error ratio of matched filter using backpropagation neural network improved than that of RAKE receiver of direct sequence spread spectrum considering of con-channel and narrow-band interference.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.19-22
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• 2004

In this paper, we present a way that can implement the vector control Algorithm of induction motor and PWM signal generation on the basis of Matlab Simulink environment. The overall system model is designed by Simulink toolbox for vector control of induction motor, and then implement experiment with the DS1103 board of dSPACE. Although we are not coding the system, it is capable of doing simulation and experiment simultaneously. That is why Matlab and dSPACE board compiler can generate the '*.c' and '*.obj' files on the designed system automatically. After considering about hardware structure and driving system in Ds1103 board we verify the availability of Proposed method through in a comparison/analysis between simulation and experiment.

• 한국통신학회논문지
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• 제16권3호
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• pp.259-269
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• 1991

본 논문에서는 전력선 채널에서 가장 심각한 문제인 임펄스성 고조파 잡음을 제거하기 위한 디지털 신호 처리 기술을 LMS(Least Mean Square)와 ITLMS(Individual Tapped LMS)의 두 가지의 알고리즘을 사용한 선형 예측에 의한 전력선 고조파 잡음 제거 방식을 통해 다루었고 각종 재밍(jamming)에 강한 특징을 가지는 DS(Direct sequnce) 대역 확산 통신을 전력선 채널에 적용하여 전송 성능의 개선을 확인하였다.

• International journal of advanced smart convergence
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• 제1권1호
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• pp.27-33
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• 2012

In this paper, we analyze and simulate performance of space time block coded (STBC) binary pulse amplitude modulation-direct sequence (BPAM-DS) ultra-wideband (UWB) systems with double binary turbo code in indoor environments for various ubiquitous healthcare (u-healthcare) applications. Indoor wireless channel is modeled as a modified Saleh and Valenzuela (SV) model proposed as a UWB indoor channel model by the IEEE 802.15.SG3a in July 2003. In the STBC encoding process, an Alamouti algorithm for real-valued signals is employed because UWB signals have the type of real signal constellation. It is assumed that the transmitter has knowledge about channel state information. From simulation results, it is shown that the STBC scheme does not have an influence on improving bit error probability performance of the BPAM-DS UWB systems. It is also confirmed that the results of this paper can be applicable for u-healthcare applications.

• 한국전기전자재료학회논문지
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• 제17권5호
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• pp.567-571
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• 2004

Recently, GIS(Gas Insulated Switchgear) has been recognizing of importance on development of diagnosis technique which is happened problem on confidence for a long time use. Therefore, the measurement and analysis of PD with prior phenomenon of insulation breakdown is used many method of diagnosis for GIS. In this paper, we simulate trouble condition in DS and analysis trouble signal to use electrical and mechanical methods, interpretation of detected signal has analysed with to use ø-q-n pattern and neural network. For this analysis, we have used the induction and AE(acoustic emission) sensors. For the simulation experiment, we make DS for 170 KV GIS and analyze the classification and characteristics of detected signals with the application of neural network algorithm.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1701-1704
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• 2002

In this paper, we investigate the effect of power control step size on the performance of the SIC scheme in DS/CDMA systems. We investigate the average power control iteration and its standard deviation and evaluate the outage performance for several different values of power control step size. Because the SIC scheme requires fine control in the received signal power, the better outage performance is obtained fer the smaller power control step size. However, the smaller power control step size requires larger amount of power control iteration in order to make the power control converge to the steady state. Under the simulated environment, the proper power control step size is about 0.3-0.4dB from both convergence speed of power control algorithm and outage performance points of view.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.142-146
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• 2002

직접 대역 확산 통신 방식에서 처리 이득에 비해 강한 협대역 간섭 신호가 존재 할 때 성능 향상을 위하여 다중 사용자 탐지 기술(MUD)을 사용하여 간섭 신호 제고를 위한 신호 검출을 하였으며, 적응 접속 채널 배열 응답과 다중 사용자 검출을 하기 위하여 BISP 알고리즘을 제안하였다. 또한 CDMA 채널에서 MAI와 ISI 검출에 BISP 알고리즘 신호 흐름 형태를 파악하여, 신호대 간섭 비율(SIR)과 신호대 잡음비율(SNR)에서 시간에 따른 비트율를 평가 하였다. 제안한 BISP 알고리즘은 방사 특성에 시간 지연 효율이 절반 이상 차이가 나지만 채널 특성 따라서 입력 신호를 조정 할 수 있다. 그리고 매치 필터를 통과하면서 각 채널간의 간섭을 억제하고, 사용자 검출을 용이하게 처리할 수 있다.