• Title/Summary/Keyword: 신호효과

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Development of Character Input System using Facial Muscle Signal and Minimum List Keyboard (안면근 신호를 이용한 최소 자판 문자 입력 시스템의 개발)

  • Kim, Hong-Hyun;Kim, Eung-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.6
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    • pp.1338-1344
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    • 2010
  • A person does communication between each other using language. But In the case of disabled person can not communication own idea to use writing and gesture. Therefore, In this paper, we embodied communication system using the facial muscle signals so that disabled person can do communication. Especially, After feature extraction of the EEG included facial muscle, it is converted the facial muscle into control signal, and then select character and communication using a minimum list keyboard.

The First Hyperpolarizability $\beta$ measurement of dipoles and cotupoles by the Hyper-Rayleigh scattering technique (Hyper-Rayleigh scattering(HRS)방법을 이용한 쌍극자와 팔중극자의 1차 초분극율$\beta$측정)

  • ;;;;;Mingjun Piao
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.104-105
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    • 2002
  • Hyper-Rayleigh scattering(HRS)방법을 이용하여 쌍극자와 새로이 합성된 팔중극자들의 1차 초분극율 $\beta$를 측정하였다. External reference 법을 이용하였고, reference 물질로는 잘 알려져 있는 쌍극자인 PNA를 이용하여 Disperse Red 1과 팔중극자들의 1차 초분극율 $\beta$의 값을 구하였다. 또한 HRS 의 세기뿐만 아니라 이들 물질의 two-photon induced fluorescence 스펙트럼을 측정하였다. 1차 초분극율 $\beta$값은, 먼저 시료로부터 scattering 된 신호를 파장변화에 따른 스펙트럼으로 측정하여 two-photon induced fluorescence를 뺀 순수한 HRS 신호만을 이용하고, 실험에 사용된 물질들은 532nm에서 흡수가 있어 second harmonic generation 신호가 시료에 의해 흡수가 되므로 흡수효과를 식 $I_{2{\omega}}$(obs)= $I_{2{\omega}}$(true) $e^{-{\sigma}lN}$ ---(1)를 이용하여 흡수에 의한 신호의 감소 효과를 보정하여 값을 구했다. (중략)

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An Analysis on Signal to Interchannel Interference Ratio of MC-CDMA System in Time Selective Fading Environments (시간선택적 페이딩 환경에서 MC-CDMA 시스템의 신호대 채널간 간섭의 비에 대한 분석)

  • 김명진;김성필;오종갑
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.33-36
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    • 2001
  • In MC-CDMA systems effects of delay spread of the channel are reduced with increased symbol duration by simultaneously transmitting data symbols on the parallel subcarriers. However, the increased symbol duration causes the system to be more vulnerable to time selective fading. In this paper, we investigate the effects of time selective fading characteristics of the mobile channel from the viewpoint of desired signal power to inter-carrier interference power ratio at the combiner output of the MC-CDMA receiver.

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A study on method to improve the detection accuracy of the location at multi-sensor environment (다중 센서 환경에서 위치추정 정확도 향상 방안 연구)

  • Na, In-Seok;Kim, Yeong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.1
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    • pp.248-254
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    • 2013
  • In location finding system using spaced multi-sensor, there is the phenomenon that the position estimation accuracy is degraded by the location of signal sources and the sensors. This phenomenon is called GDOP(Geometric Dilution Of Precision) effect. and to minimize these effects, research is needed on how. In this paper, I will describe how to minimize GDOP effect, estimating possibility of GDOP using AOA(angle of arrival) information of spaced multi sensors, and removing sensor error factor in position estimation.

Simultaneous Single Band Duplex System for the Spectrum Efficiency Improvement (스펙트럼 효율 향상을 위한 동일대역 동시 통신 (Simultaneous Single Band Duplex) 시스템)

  • An, Changyoung;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.9
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    • pp.810-816
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    • 2013
  • In this paper, we propose a SSD (simultaneous single-band duplex) system using Digital Cancellation. Also, we propose a method for Digital Cancellation when RF Cancellation is effectively performed. The proposed system has estimation frame for effective self-interference channel estimation in time-domain. The proposed system calculates signal power for selection of optimal coefficient after digital cancellation. Then, the proposed system selects coefficient of minimum signal power. Further, the proposed system uses LDPC code to minimize the effects of remaining self-interference signal. The proposed system shows BER performance of at 20dB by cancelling self-interference and iterating LDPC code. That is, the proposed system shows that the SSD communication is possible in static self-interference channel.

Prediction of Efficient Adaptive Perceptual Filter Iterate Coefficient through Analysis of Noisy Signal (잡음에 열화된 오디오 신호의 분석을 통한 효율적인 적응지각필터 반복 수행 계수의 예측)

  • Ryu, Il-Hyun;Cha, Hyung-Tai;Koo, Kyo-Sik;Seo, Bo-Kook
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2005.11a
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    • pp.238-241
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    • 2005
  • 디지털 미디어 기술의 발전은 코딩 분야를 비롯하여 다양하게 발전하고 있다. 특히 오디오 신호 처리 분야에서는 디지털 오디오 신호의 생성, 압축, 복원의 단계가 다양한 형태로 개발되고 있다. 오디오 신호 처리에서 인간의 청각 기관을 모델링한 심리음향 기법은 이용하여 압축뿐만 아니라 잡음 신호의 개선에서도 효과적으로 이용되고 있다. 이러한 심리음향모델을 기반으로 하여 구성된 적응지각필터는 지각필터를 이용하여 적응적으로 잡음에 열화된 신호를 개선한다. 이때, 적응지각필터 반복 수행 계수의 효과적인 결절은 오디오 신호의 청각적 손실을 줄이는 동시에 정확한 잡음 제거를 수행한다. 성능을 확인하기 위해서 SNR 및 NMR 비교를 수행하였다.

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Detecting PPG signal using Neural Network (Neural Network 기반의 PPG 신호 검출 시스템)

  • Kim, Chisung;Han, Dong Seog
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2016.06a
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    • pp.278-279
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    • 2016
  • 최근 웨어러블 장치의 개발로 인하여 다양하게 생체 신호를 측정하는 방법이 많아지고 있다. 이와 관련하여 대표적으로 측정하는 신호가 PPG(plethysmography) 신호이다. PPG 신호를 이용하여 맥박수, 혈박출량, SPo2 등의 값들을 추정할 수 있다. 그러나 웨어러블 장치의 특성상 동적잡음이 많이 발생하게 된다. 동적잡음을 제거하기 위한 방법들은 가속도 센서를 사용하는 방법, 칼만필터(Kalman filter)를 이용하는 방법 등 다양한 방법들이 존재한다. 그러나 여전히 범용으로 사용하기에는 한계가 있다. 본 논문은 Neural Network를 사용하여 개인별로 PPG 신호를 학습하여 PPG 신호의 이상 유무를 판단하고 이전 신호의 평균 맥박수를 사용하여 효과적으로 PPG 신호의 정확한 맥박수를 검출하는 알고리듬을 제안한다.

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Establishing the Methodology of Economic Analysis to Take into Account Opportunistic Valuation for a Radio Communication & Train Control System (철도무선신호제어시스템 실용화의 기회가치성을 고려한 경제성분석 체계 정립 -일반 및 고속철도용 무선 및 제어시스템 실용화 사례를 중심으로-)

  • Cho, Shin-hyung;Seo, Young-hyun;Kho, Seung-young;Rhee, Sung-mo
    • Journal of the Korean Society for Railway
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    • v.19 no.3
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    • pp.373-379
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    • 2016
  • Development of a train wireless signal control system using LTE-R technology is expected to have a great ripple effect to the existing signal control market. To make inroads into the international market, it is an urgent issue to practicalize the train wireless signal control system. Because it will require a huge budget to commercialize the wireless signal control system, it is necessary to analyze the feasibility beforehand, with a consideration of the domestic and foreign marketability and the impact on related industries. This study investigated the effect of the practicalization of train control system on future railway and national industrial sectors. We suggested the establishment of a framework for economic feasibility analysis, one that can provide criteria for opportunistic valuation. We also verified this framework through case analysis.

Correction of Continuous Motion Effects for Airborne FMCW-SAR System (항공기 기반 FMCW-SAR 시스템의 연속이동효과 보정)

  • Hwang, Ji-hwan;Jung, Jungkyo;Kim, Duk-jin;Kim, Jin-Woo;Shin, He-Sub;Ok, Jae-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.5
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    • pp.410-418
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    • 2017
  • Results of an analysis of the continuous motion effect for FMCW-SAR system and a signal processing to correct it are presented in this paper. SAR images reconstructed by back-projection algorithm are included as well. To analyze how platform velocity and sampling frequency affect the continuous motion effect, FMCW signal model was used, and the signal processing in time-doppler(t, $k_u$) domain was adopted. Then, back-projection algorithm and modified matched-filter was used to reconstruct SAR images, and it was validated using measured data by airborne FMCW-SAR system in X-band frequency.

Jamming Effect of Phase-Coded Pulse Compression Radar (위상코드 펄스압축 레이더의 재밍 효과)

  • Lim, Joong-Soo
    • Journal of Convergence for Information Technology
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    • v.9 no.5
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    • pp.125-129
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    • 2019
  • This paper describes the jamming effect of phase-coded pulse compression(PCPC) radar. Barker code radar, a typical PCPC radar, separates transmission pulses into 13 or 31 small pulses and phase modulates and transmits each pulse signal to increase radar detection efficiency and reduce the influence of jamming. Generally, when the radar is subjected to jamming, the detection distance becomes shorter and the detection error rate becomes higher. In the case of noise jamming or carrier jamming on the PCPC radar, the jamming effect is very small for no phase-coded convergence. However, the jamming effect is large in the case of synchronous jamming using the pulse-coded signal as a jamming signal with DRFM. It can be seen that the jamming effect increases when the storage time of the pulse-coded signal is prolonged. This study is considered to be useful for PCPC radar and EW jamming system design.