• Title/Summary/Keyword: Yun Jongchan

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Traffic Accident Analysis using Doppler Effect of the Horn (경적음의 도플러 효과를 이용한 교통사고분석)

  • Choi, Youngsoo;Kim, Jonghyuk;Yun, Yongmun;Park, Jongchan;Park, Hasun
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.4
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    • pp.70-77
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    • 2020
  • In this study, we estimate the vehicle speed by analyzing the acoustic data recorded in a single microphone of a surveillance camera. The frequency analysis of the acoustic data corrects the Doppler effect, which is a characteristic of the moving sound source, and reflects the geometric relationship according to the location of the sound source and the microphone on the two-dimensional plane. The acoustic data is selected from the horn sound that is mainly observed in an urgent situation among various sound sources that may occur in a traffic accident, and the characteristics of the monotone source are considered. We verified the reliability of the proposed method by time domain acoustic analysis and actual vehicle evaluation. This method is effective and can be used for traffic accident analysis in the blind spot of the camera using a single microphone built into the existing surveillance camera.

Averaging Methods for Enhancing the Performance of DOA Estimation Under the Rotor Effect (로터 영향 하에서의 DOA 추정 성능 개선을 위한 평균화 방법)

  • Yun, Seonhui;Oh, Jongchan;Kim, Jun O;Choi, Sangwook;Ahn, Jae Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1245-1255
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    • 2012
  • There are various anti-jamming algorithms for the GNSS system which is vulnerable to jamming, and the methods using array antenna show the best performance. Among them, the DOA estimation algorithms to identify the location of the jammer is very important. However, in case of the rotorcraft, the wireless channel which amplitude and phase changes with time is generated by the rotation of the rotor and it affects the performance of existing anti-jamming algorithms. In this paper, we modeled the effect of the rotor in four scenarios according to the correlation of antennas and assured that the performance of DOA estimation algorithms are degraded and saturated regardless of JNR due to the rotor effect. When we use the averaging method to solve this problem, the performance is improved as increasing samples for estimating. And in case of using moving average method with averaging, it shows similar performance. In addition, it reduces the required memory and moderates the variation of DOA estimation.

A Study on the Fantastic Trend of Korean Movies in the late 90s : Focused on Kim Giduk's Bad Guy (90년대 말 한국영화의 환상성 경향 연구 - 김기덕의 <나쁜 남자>를 중심으로)

  • LEE, Jihyun
    • Trans-
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    • v.4
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    • pp.87-109
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    • 2018
  • The genres of fantastic of Korean films created in the 90s are diverse. The fantastics of these works are not manifested only in 'Ghosts' movies. For example, If the film Mystery Of The Cube, which is based on the mystery of Lee Sang, has a story of structuralist fantasy, we can say that a movie like Tell Me Something has a psychologically conventional fantastic. This study examines the fantastic of contemporary Korean films through 'completion of allegory based on realism'. For this, we borrows the fantastic concept of Etienne Souriau. In some films, fantastics can be found directly in the developing nature. In this case, the human being who justifies their domination of nature by upgrading their position as the objectifying subject of nature becomes 'alienated' in return. The notion of this alienation in film narratives is often revealed through allegories, particularly in the manifestation of fantasy by Étienne Souriau in the early 'personal experience'. Kim kiduk's film is a representative example of allegorizing elements of society through individual experience. Focusing on Kim Giduk's Bad Guy, this essay analyzes the process in which fantastic films of Korea in the 90s build up aesthetic fantastic through imitation of society.

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Performance Analysis of Beam Steering Algorithm According to the Signal Separation (신호 이격도에 따른 빔 제어 알고리즘 성능 분석)

  • Yun, Seonhui;Oh, Jongchan;Kim, Jun O;Nam, Juhun;Choi, Sangwook;Ahn, Jaemin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.11
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    • pp.1023-1030
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    • 2014
  • Beam steering algorithms using array antenna are mainly used in such a manner as anti-jamming method. However, the performance is changed according to the position of signals despite the same number of signals and the same received power. In this paper, we analyzed the effect of the position relationship of the signals on the performance of the beam steering algorithms. Therefore, we defined 'signal separation' as the minimum angle of the interference signals and the desired signal, and analysed the relationship between the C/N0 performance of beam steering algorithms as LCMV/PM and the signal separation. For simulation, we set many GPS signals and jamming signals compared to the degrees of freedom. And changed the position and the height of the receiver in order to obtain various signal separation angles. In addition, we examined the effects of signal separation and JSR on the anti-jamming performance by applying the loss factors of the received power. Through the research, there is a tendency that the performance of beam steering algorithms is increased with the increase of the signal separation, and signal separation is more severely affecting on the anti-jamming performance compared to the number of signals and JSR.