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A realization of up/down-stream transmission on an optical subscriber network with the PON structure (PON구조의 광가입자망에서 상/하향전송 구현)

  • 김효중;이찬구;강성수;이만섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.3
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    • pp.795-806
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    • 1996
  • A structure which transmits and receives 3 subscribers packet data through an optical splitter node in an optical subscriber network of PON wave suggested and realized. All the functions which are necessary to use PON structure such as 155.52Mb/s multiplexer/demultiplexer of down-stream signal, 25.92Mb/s multiplexer/demultiplexer of up-stream signal, frame synchronizer, and phase aligner for aligning phase of the clock and received data have been integrated within 2 ICs using CMOS technonology. TDMAtechnology was suggested for up-stream transmission. In the optical up-stream transmission of the urst signals transmissionquality degradataion by APC and AGC of optical tranceiver was observed. By compensating the degradation, more than 17dB of link budget which is enough to satisfy 11.2dBthat is required in SWAN of PON architecture has been obtained with optical transceiver whose power and sensitivity are -17dBm and -34dBm respectively.

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The characteristics of tilted grating in depressed- and step- index fiber and its application (Depressed index type과 Step index type 광섬유에서의 경사진 브래그격자 특성과 응용)

  • 권서원;이상배;최상삼;박진우
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.12
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    • pp.83-91
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    • 1998
  • Fiber Bragg grating which has a blazed ang1e to the plane of incident wave generates a side-mode as well as main-mode. The side-mode has an identical characteristics with a long period grating that couples with a cladding mode, so rejects the special wavelength. We experimented on the side-mode characteristics with two fibers which Ge doped depressed index fiber and very high photosensitive H$_2$ loaded step index fiber according to the tilted angle. Also, using a phase mask equipped with rotation plate which has 0.02$^{\circ}$ resolution, we can control the bandwidth and the peak value of a total loss spectrum by aligned tilted grating in a fiber and using this, tried to compose the ASE band rejection filter of the Erbium doped fiber amplifier.

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Panorama Background Generation and Object Tracking using Pan-Tilt-Zoom Camera (Pan-Tilt-Zoom 카메라를 이용한 파노라마 배경 생성과 객체 추적)

  • Paek, In-Ho;Im, Jae-Hyun;Park, Kyoung-Ju;Paik, Jun-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.3
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    • pp.55-63
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    • 2008
  • This paper presents a panorama background generation and object tracking technique using a Pan-Tilt-Zoom camera. The proposed method estimates local motion vectors rapidly using phase correlation matching at the prespecified multiple local regions, and it makes minimized estimation error by vector quantization. We obtain the required image patches, by estimating the overlapped region using local motion vectors, we can then project the images to cylinder and realign the images to make the panoramic image. The object tracking is performed by extracting object's motion and by separating foreground from input image using background subtraction. The proposed PTZ-based object tracking method can efficiently generated a stable panorama background, which covers up to 360 degree FOV The proposed algorithm is designed for real-time implementation and it can be applied to many commercial applications such as object shape detection and face recognition in various surveillance video systems.