• Title/Summary/Keyword: 방향 탐지

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A Study on Direction Finding Technique for Array with Faulty Elements (결함소자를 갖는 어레이를 위한 방향 탐지 기법에 관한 연구)

  • Kim, Ki-Man;Youn, Dae-Hee;Cha, Il-Whan
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.4
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    • pp.71-75
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    • 1997
  • In this paper, some problems that occur from faulty elements in a direction finding system composed of the linear array are studied and the method which improves the performance is proposed. The fault element means the sensor that has no output or highly reduced gain than other normal sensors. In the case of the presence of faulty elements, the performance of the conventional the spatial spectrum subject to a constraint. The corrected spatial spectrum is obtained by this vector. The computer simulations have been performed to study the performance of the proposed method. We have compared the proposed method with the subaperture processing method of one of the previous works.

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A study on digital sound reception systems for ships (선박용 디지털 음향수신장치 연구)

  • Kim, Hyungjong;Kim, Jeongchang
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.9
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    • pp.1125-1130
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    • 2014
  • In this paper, we propose a sound reception system against surrounding noise for ships based on digital signal processing technologies. In order to suppress unwanted surrounding noises, a digital band-pass filter is designed, which the pass-band of the filter is between 70Hz to 820Hz. Also, we develope a sound direction indicating algorithm with 4 microphones. After filtering the audio signals from 4 microphones, the developed sound direction indicating algorithm can indicate 8 directions. In addition, we implement prototype board for the sound reception using a digital signal processor chip and audio codecs, and verify the proposed algorithm.

Phase Comparison Direction Finding of Circular Array Antenna Considering Polarization Characteristics (원형배열안테나의 편파 특성을 고려한 위상 비교 방향탐지)

  • Daewoong, Woo;Jaesik, Kim;Jinsung, Park
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.1
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    • pp.131-137
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    • 2023
  • In this paper, a phase comparison direction finding method of circular array composed of 8 antennas considering polarization characteristics is analyzed. A broadband cavity-backed patch antenna operating in 6 ~ 12 GHz is used, and the antennas are arranged in radial direction to receive various polarization signals. For the phase comparison, widely spaced elements are used to obtain precise DOA(Direction of Arrival), and narrowly spaced elements are used to resolve ambiguity. Two dimensional direction finding is performed for ±20° in both azimuth and elevation, and the DOA error is less than 0.5° and 1.6° near the boresight and the ±15° region, respectively.

최신 방향탐지 장비의 발전추세(2)

  • Jeong, Sun-Ho
    • Defense and Technology
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    • no.11 s.273
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    • pp.48-57
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    • 2001
  • ES기능의 하나인 방향탐지는 국가급 보안에 해당하는 분야로 일부 상용체제를 제외하고는 철저하게 독자적으로 개발되어야 한다. 그러나 국내개발 수준은 상당히 낙후되어 있으며 주요 핵심부품은 해외도입하고 있는 실정이다. 우리 나라도 더 이상의 직구매 방식을 지양하고, 국내 연구개발을 통해 독자적 전자전 장비 및 운용체제 갖추어 나가야 한다. 육군, 국과연, 학교 그리고 업체의 유기적인 참여와 협조만 이루어진다면 지금까지 국내에 축적된 기술력으로 충분히 개발할 수 있다고 판단된다.

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개인화기 조준경 개발방향

  • Song, Seong-Seok
    • Defense and Technology
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    • no.5 s.267
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    • pp.42-51
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    • 2001
  • 주.야간 겸용 영상 증폭장비는 주간 광학계가 복합 설계되어 야간 전용보다 무겁고 부피가 크며 탐지능력이 떨어져 야간전용으로 개발이 요구되었고, 열상장비는 악천후시 탐지능력은 우수하나 무겁고 부피가 크며 건전지 소요가 과다함으로 개인화기 조준경으로는 부적합하다는 결론을 도출하였다. 따라서 이 글에서는 전자광학장비중 야시장비의 개발현황 및 발전추세를 살펴보고 운용시험평가 결과분석을 토대로 향후 우리 군이 어떤 방향으로 야간 전투력을 극대화 할 수 있을 것인가에 대한 무기체계 소요제기와 작전운용성능을 설정할 것인가를 논해보고자 한다.

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The study of improving the performance of lower direction finding ability due to the interfered phase difference of circular array Antennas (원형배열안테나의 위상간섭에 의한 방향탐지 성능저하 개선연구)

  • Chung, Jae-Woo;Kim, Young-Kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.535-539
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    • 2010
  • This paper include to study DoA(Direction of Arrival) for radio collection and monitoring system. The direction finding calculated by applying the CVDF (Correlation Vector Direction Finding) algorithm for the five circular dipole antenna over V / UHF band. To improve the accuracy of direction finding by applying CVDF algorithm needs to obtain ideal phase difference each antennas. However, a circular array antenna phase difference pattern may be distorted on a specific frequency band or to particular direction. The effect of installing each array antennas circularly and the effect of the interference of center pole (located in the center of a circular array antenna mount) may make the distortion of phase pattern. If you use an active antenna instead of passive antenna to obtain good sensitivity, you would measure the more distortion. This paper propose how to change combination of antennas to measure the phase in real-time and how to use antenna beam patterns for minimizing the degradation phenomena at applying simple CVDF algorithm and increasing the direction finding capability.

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Autonomous Driving System for Advanced Safety Vehicle (고안전도 차량을 위한 자율주행 시스템)

  • Shin, Young-Geun;Jeon, Hyun-Chee;Choi, Kwang-Mo;Park, Sang-Sung;Jang, Dong-Sik
    • The Journal of the Korea Contents Association
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    • v.7 no.2
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    • pp.30-39
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    • 2007
  • This paper is concerned with development of system to detect an obstructive vehicle which is an essential prerequisite for autonomous driving system of ASV(Advanced Safety Vehicle). First, the boundary of driving lanes is detected by a Kalman filter through the front image obtained by a CCD camera. Then, lanes are recognized by regression analysis of the detected boundary. Second, parameters of road curvature within the detected lane are used as input in error-BP algorithm to recognize the driving direction. Finally, an obstructive vehicle that enters into the detection region can be detected through setting detection fields of the front and lateral side. The experimental results showed that the proposed system has high accuracy more than 90% in the recognition rate of driving direction and the detection rate of an obstructive vehicle.

Hand Pose Recognition Using Fingertip Detection (손가락 끝 점을 이용한 손 형상 인식)

  • Kim, Kyung-Ho;Lee, Chil-Woo
    • 한국HCI학회:학술대회논문집
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    • 2006.02a
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    • pp.1143-1148
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    • 2006
  • 사용자 친화형 유저 인터페이스 구현을 위해 인간의 손 형상을 실시간으로 인식하는 연구의 중요성이 부각되고 있다. 그러나 인간의 손은 자유도가 크기 때문에 손 형상을 정확히 인식하기란 매우 어렵고 또한 피부색과 유사한 색을 가지는 복잡한 배경에서는 더욱 곤란하다. 본 논문에서는 별도의 센서를 부착하지 않고 카메라를 사용하여 피부색 정보에 의한 손 형상을 분할한 후 손가락 끝 점을 찾는다. 찾은 손가락 끝점을 이용하여 방향을 탐지하는 알고리즘에 대해 기술한다. 이 방법은 템플리트 매칭을 이용하여 손가락 끝 점을 탐색한 후 찾은 손 가락 끝 점과 손목의 중심을 이용하여 전, 후, 좌, 우 방향을 탐지한다. 제안하는 방법을 이용하여 3D가상현실 공간에서의 Navigation에 응용하였으며, 실험결과 전진, 후진 및 좌측, 우측의 방향전환도 매우 좋은 결과를 보였다. 또한 본 논문에서 제안하는 방법은 마우스, 키보드, 조이스틱 등의 조작 없이 전, 후, 좌, 우 방향전환을 사용자가 직관적으로 지시함으로써 보다 자연스러운 인간과 컴퓨터의 상호작용을 제공할 수 있을 것이다.

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Noise-Robust Anomaly Detection of Railway Point Machine using Modulation Technique (모듈레이션 기법을 이용한 잡음에 강인한 선로 전환기의 이상 상황 탐지)

  • Lee, Jonguk;Kim, A-Yong;Park, Daihee;Chung, Yongwha
    • Smart Media Journal
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    • v.6 no.4
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    • pp.9-16
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    • 2017
  • The railway point machine is an especially important component that changes the traveling direction of a train. Failure of the point machine may cause a serious railway accident. Therefore, early detection of failures is important for the management of railway condition monitoring systems. In this paper, we propose a noise-robust anomaly detection method in railway condition monitoring systems using sound data. First, we extract feature vectors from the spectrogram image of sound signals and convert it into modulation feature to ensure robust performance, and lastly, use the support vector machine (SVM) as an early anomaly detector of railway point machines. By the experimental results, we confirmed that the proposed method could detect the anomaly conditions of railway point machines with acceptable accuracy even under noisy conditions.