• Title/Summary/Keyword: MAP 알고리듬

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Depth estimation and View Synthesis using Haze Information (실안개를 이용한 단일 영상으로부터의 깊이정보 획득 및 뷰 생성 알고리듬)

  • Soh, Yong-Seok;Hyun, Dae-Young;Lee, Sang-Uk
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2010.07a
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    • pp.241-243
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    • 2010
  • Previous approaches to the 2D to 3D conversion problem require heavy computation or considerable amount of user input. In this paper, we propose a rather simple method in estimating the depth map from a single image using a monocular depth cue: haze. Using the haze imaging model, we obtain the distance information and estimate a reliable depth map from a single scenery image. Using the depth map, we also suggest an algorithm that converts the single image to 3D stereoscopic images. We determine a disparity value for each pixel from the original 'left' image and generate a corresponding 'right' image. Results show that the algorithm gives well refined depth maps despite the simplicity of the approach.

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A New Calibration Algorithm of a Five-Hole Pressure Probe for Flow Velocity Measurement (유동속도계측을 위한 5공압력프로브의 새로운 교정 알고리듬)

  • Kim, J.K.;Oh, S.H.
    • Journal of Power System Engineering
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    • v.12 no.4
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    • pp.18-25
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    • 2008
  • This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe necessary for calculating three-dimensional flow velocity components. The new data reduction method Includes a look-up, a geometry transformation such as the translation and reflection of nodes, and a binary search algorithm. This new calibration map was applied up to the application angle, ${\pm}55^{\circ}$ of a probe. As a result, this data reduction method showed a perfect performance without any kind of interpolation errors In calculating yaw and pitch angle from the calibration map.

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Adaptive Image Enhancement Algorithm using Local Statistics (국부통계특성을 이용한 적응적 영상 Enhancement 알고리듬)

  • Kim Kyoung Ho;Hong Min-Cheol
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2004.11a
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    • pp.71-74
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    • 2004
  • 본 논문에서는 MAP(maximum a posteriori) 추정방식과 국부통계특성을 이용한 적응적 영상 향상 방법을 제안한다. 원 영상의 에지를 보존 할 수 있는 MAP추정 방식과 인간의 시각 특성을 나타내는 시각 함수를 이용한 가중치 행렬을 사용하였다. MAP 추정 방식은 컨벡스 함수를 최적화하여 원 영상의 에지를 보존하는 방법을 이용하였으며, 시각 함수는 국부 정보의 평균, 분산을 이용하여 정의하였다. 제안 방식으로부터 국부영역의 비용함수에 의해 발생되는 스무딩 정도를 다르게 하여 보간된 영상의 화질을 개선시킨다. 제안된 방식의 성능을 실험 결과로부터 확인한 수 있었다.

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Iterative Turbo Decoding Using Three Cascade MAP Decoder (3개의 직렬 MAP 복호기를 이용한 반복 터보 복호화기)

  • 김동원;이호웅;강철호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.6B
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    • pp.709-716
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    • 2001
  • 반복 복호 알고리듬에 의해 복호화된 터보 코드는 가산성 백색 가우시안 잡음(AWGN) 채널 환경에서 이론적으로 Shannon의 한계에 근접한 뛰어난 코딩 이득을 나타내는 것으로 보여지고 있다. 그러나, 터보 코드의 성능은 터보 부호화기에서 프레임의 크기 즉, 인터리버의 크기에 의존한다. IMT-2000과 같은 이동 통신 채널 환경에서 음성을 전송하는 경우에는 터보 코드의 프레임 크기는 매우 작다. 그리고, 그것은 터보 코드의 성능을 떨어뜨리는 직접적인 원인이 된다. 본 논문에서는 차세대 이동 통신 시스템에서 프레임 크기가 작은 음성 프레임을 이용하여 터보 코드의 성능을 검증하며, 작은 프레임 크기에 알맞은 3개의 직렬 MAP(Maximum A Posteriori probability) 복호기를 이용한 반복 복호의 터보 코드를 제안하고 부호율 1/3, 구속장의 길이 3 또는 4, 프레임 크기 24, 192 비트에 대하여 컴퓨터 모의실험을 통해 터보 코드의 성능을 분석한다.

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Application of the New Calibration Algorithm of a Straight-Type Five-Hole Pressure Probe (직선형 5공 압력프로브의 새로운 교정 알고리듬 적용)

  • Kim, Jang-Kweon;Oh, Seok-Hyung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.11
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    • pp.863-869
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    • 2008
  • This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. This new calibration algorithm was used for velocity data reduction from the calibration map and based on the combination of a look-up, a binary search algorithm and a geometry transformation including the translation and reflection of nodes in a calibration map. The calibration map was expanded up to the application angle, ${\pm}55^{\circ}$ of a probe. This velocity data reduction method showed a perfect performance without any kind of interpolating errors in calculating yaw and pitch angles from the calibration map. Moreover, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole.

Delay Optimization Algorithm for the High Speed Operation of FPGAs (FPGA를 고속으로 동작시키기 위한 지연시간 최적화 알고리듬)

  • Choi, Ick-Sung;Lee, Jeong-Hee;Lee, Bhum-Cheol;Kim, Nam-U
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.7
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    • pp.50-57
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    • 2000
  • We propose a logic synthesis algorithm for the design of FPGAs operating at high speed. FPGA is a novel technology that provides programmability in the field. Because of short turnaround time and low manufacturing cost, FPGA has been noticed as an ideal device for system prototyping. Despite these merits, FPGA has drawbacks, namely low integration and long delay time comparing to ASIC. The proposed algorithm partitions a given circuit into subcircuits utilizing a kernel divisor such that the subcircuits can be performed at the same time, hence reducing the delay of the circuit. Experimental results on the MCNC benchmark show that the proposed algorithm is effective by generating circuits having 19.1% les delay on average, when compared to the FlowMap algorithm.

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Performance Analysis on Terrain-Adaptive Clutter Map Algorithm for Ground Clutter Rejection of Weather Radar (기상 레이다의 지형 클러터 제거를 위한 지형적응 클러터 맵 알고리듬 성능분석)

  • Kim, Hye-Ri;Jung, Jung-Soo;Kwag, Young-Kil;Kim, Ji-Won;Kim, Ji-Hyeon;Ko, Jeong-Seok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.12
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    • pp.1292-1299
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    • 2014
  • Weather radar systems can provide weather information of the ground, sea, and air in extensive spatial coverage in near real time. However, it becomes problematic when ground clutter signal exists around precipitation because strong signals of ground can cause a false precipitation report. A large percentage of land coverage of Korea consists of mountainous regions where ground clutter needs to be mitigated for more accurate prediction. Thus, it is considered necessary to introduce a new suitable ground clutter removal technique specifically adequate for Korea. In this paper, the C-Map(Clutter Map) method using raw radar signals is proposed for removing ground clutter using a terrain-adaptive clutter map. A clutter map is generated using raw radar signals(I/Q) of clear days, then it is subtracted from received radar signals in frequency domain. The proposed method is applied to the radar data acquired from Sobaeksan rain radar and the result shows that the clutter rejection ratio is about 91.17 %.

A Fast Search Algorithm of Codebook Using the SOM (SOM을 이용한 부호책의 고속 탐색 알고리듬)

  • 김진태;김동욱
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.1
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    • pp.102-109
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    • 2001
  • In this paper, in order to reduce the computational complexity of codebook, we propose a fast search algorithm which takes advantage of the information generated in the process of the self-organizing map (SOM). In an attempt to demonstrate the influence of the ordering of codebook on the performance of the partial distance search (PDS), we present the results of computation savings for three cases of ordering of codebooks.

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Fast Pose-Invariant Detection of Facial Informations Using Color Cues (컬러 정보를 이용한 얼굴 정보의 자세불변 고속 검출)

  • 정의정;김복만;최홍문
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2096-2099
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    • 2003
  • 본 논문에서는 입력 영상의 컬러 정보를 이용함으로써 조명 변화나 얼굴의 자세 변화에 둔감하게 얼굴 정보를 고속 검출하는 알고리듬을 제안하였다 계산복잡도가 작으면서도, 조명의 변화에 민감하지 않은 특성을 가진 NCC (normalized color component) 좌표계에서 정의한 살색에 기반하여 얼굴 후보 영역을 검출하고, 검출된 얼굴 후보 영역 내에서의 눈의 검출에도 색상 분포 특성을 이용함으로써 얼굴의 숙임(nod), 돌림(shake), 기울임(tilt)등에 의한 자세 변화에 대해서도 둔감하게 두 눈의 위치를 고속으로 찾도록 하였다. 특히 집중자(concentrator)를 제안 적용하여 유동적인 눈썹의 영향을 줄이고 눈안의 중심 위치를 찾도록 가중치 눈지도(eye map)를 도입하였다. 제안된 알고리듬이 조명 변화나 얼굴의 다양한 자세 변화가 있는 영상에서 얼굴 후보 영역과 두 눈의 위치를 효과적으로 검출함을 실험을 통해 확인하였다.

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Tracking a Moving Object Using an Active Contour Model Based on a Frame Difference Map (차 영상 맵 기반의 능동 윤곽선 모델을 이용한 이동 물체 추적)

  • 이부환;김도종;최일;전기준
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.153-163
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    • 2004
  • This paper presents a video tracking method for a deformable moving object using an active contour model in the image sequences. It is quite important to decide the local convergence directions of the contour points for correctly extracting the boundary of the moving object with deformable shape. For this purpose, an energy function for the active contour model is newly proposed by adding a directional energy term using a frame difference map to tile Greedy algorithm. In addition, an updating rule of tile frame difference map is developed to encourage the stable convergence of the contour points. Experimental results on a set of synthetic and real image sequences showed that the proposed method can fully track the deformable object while extracting the boundary of the object elaborately in every frame.