• Title/Summary/Keyword: MAP Estimation

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Image analysis using a markov random field and TMS320C80(MVP) (TMS320C80(MVP)과 markov random field를 이용한 영상해석)

  • 백경석;정진현
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1722-1725
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    • 1997
  • This paper presents image analysis method using a Markov random field(MRF) model. Particulary, image esgmentation is to partition the given image into regions. This scheme is first segmented into regions, and the obtained domain knowledge is used to obtain the improved segmented image by a Markov random field model. The method is a maximum a posteriori(MAP) estimation with the MRF model and its associated Gibbs distribution. MAP estimation method is applied to capture the natural image by TMS320C80(MVP) and to realize the segmented image by a MRF model.

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Estimation Method of Wind Resource Potential Using a National Wind Map (국가바람지도에 의한 풍력자원 잠재량 산출방법)

  • Kim, Hyun-Goo;Jang, M.S.;Kim, E.I.;Lee, H.W.;Lee, S.H.;Kim, D.H.
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.332-333
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    • 2008
  • This paper presents an estimation method of national wind resource potential using a national and GIS(Geographical Information System). The wind resource potential is classified into theoretical, geographical and technical potentials and each category narrows down the previous definition by excluding impossible area to be developed as a wind farm using GIS datasets for onshore and offshore. As a basic unit of wind energy potential at a certain area, API(Average Power Intercepted) is calculated from WPD(Wind Power Density) given by a national wind map which is established by numerical wind simulation, so that a logical and relatively accurate potential estimation is possible comparing with other methods based on a field measurement interpolation which is inevitable to avoid critical assumptions.

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Localization of a Monocular Camera using a Feature-based Probabilistic Map (특징점 기반 확률 맵을 이용한 단일 카메라의 위치 추정방법)

  • Kim, Hyungjin;Lee, Donghwa;Oh, Taekjun;Myung, Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.4
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    • pp.367-371
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    • 2015
  • In this paper, a novel localization method for a monocular camera is proposed by using a feature-based probabilistic map. The localization of a camera is generally estimated from 3D-to-2D correspondences between a 3D map and an image plane through the PnP algorithm. In the computer vision communities, an accurate 3D map is generated by optimization using a large number of image dataset for camera pose estimation. In robotics communities, a camera pose is estimated by probabilistic approaches with lack of feature. Thus, it needs an extra system because the camera system cannot estimate a full state of the robot pose. Therefore, we propose an accurate localization method for a monocular camera using a probabilistic approach in the case of an insufficient image dataset without any extra system. In our system, features from a probabilistic map are projected into an image plane using linear approximation. By minimizing Mahalanobis distance between the projected features from the probabilistic map and extracted features from a query image, the accurate pose of the monocular camera is estimated from an initial pose obtained by the PnP algorithm. The proposed algorithm is demonstrated through simulations in a 3D space.

Generalized input estimation for maneuvering target tracking (기동 표적 추적을 위한 일반화된 입력 추정 기법)

  • 황익호;이장규;박용환
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.1
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    • pp.139-145
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    • 1996
  • The input estimation method estimates maneuvering input acceleration in order to track a maneuvering target. In this paper, the optimal input estimator is derived by choosing the MAP hypothesis among maneuvering input transition hypotheses under the assumption that a maneuvering input acceleration is a semi-Markov process. The optimal input estimation method cannot be realized because the optimal filter should consider every maneuver onset time hypothesis from filter starting time to current time which increase rapidly. Hence the suboptimal filter using a sliding window is proposed. Since the proposed method can consider all hypotheses of input transitions inside the window, it is general enough to include Bogler's input estimation method. Simulation results show, however, that we can obtain a good performance even when the filter considering just one input transition in the window is used. (author). 9 refs., 3 figs., 1 tab.

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Map Creation Algorithm and Initial Attitude Estimation Method for Optical Head Tracker System (광학방식 헤드 트랙커를 위한 맵 생성 알고리즘과 초기자세 추정기법)

  • Lee, Young-Jun;Park, Chan-Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.7
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    • pp.680-687
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    • 2008
  • This paper presents map creation algorithm and initial attitude estimation method for the proposed optical head tracker system. The optical head tracker system consists of the IR stereo cameras and infrared LEDs as features on the helmet. In order for the stereo camera to track the luminous LEDs, it must take in to account the light radiation from the LEDs to determine the position of the center points. The proposed map creation algorithm makes map data about the position of features center points on the helmet frame. Also, initial attitude estimation method is proposed to estimate the initial attitude and position of a pilot head from the camera frame by the use of the feature pattern on the helmet. Therefore, the head motion can be expressed with respect to the body frame of a flight.

Motion Estimation-based Human Fall Detection for Visual Surveillance

  • Kim, Heegwang;Park, Jinho;Park, Hasil;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.5
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    • pp.327-330
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    • 2016
  • Currently, the world's elderly population continues to grow at a dramatic rate. As the number of senior citizens increases, detection of someone falling has attracted increasing attention for visual surveillance systems. This paper presents a novel fall-detection algorithm using motion estimation and an integrated spatiotemporal energy map of the object region. The proposed method first extracts a human region using a background subtraction method. Next, we applied an optical flow algorithm to estimate motion vectors, and an energy map is generated by accumulating the detected human region for a certain period of time. We can then detect a fall using k-nearest neighbor (kNN) classification with the previously estimated motion information and energy map. The experimental results show that the proposed algorithm can effectively detect someone falling in any direction, including at an angle parallel to the camera's optical axis.

A Preliminary Study of the Global Application of HAZUS and ShakeMap for Loss Estimation from a Scenario Earthquake in the Korean Peninsular (지진재해예측을 위한 HAZUS와 ShakeMap의 한반도에서의 적용가능성 연구)

  • Kang, Su-Young;Kim, Kwang-Hee;Kim, Dong-Choon;Yoo, Hai-Soo;Min, Dong-Joo;Suk, Bong-Chool
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.152-155
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    • 2007
  • Efficiency and limitations of HAZUS-MH, a GIS based systematic and informative system developed by FEMA and NIBS for natural hazard loss estimations, are discussed by means of a pilot study in the Korean Peninsular. Gyeongsang-do has been selected for the test after careful reviews of previous studies including historical and modern seismicity in the peninsular. A ShakeMap for the selected scenario earthquake with magnitude 6.7 in Gyeongju area is prepared. Then, any losses due to the scenario event have been estimated using HAZUS. Results of the pilot test show that the study area may experience significant physical, economic and social damages. Detailed study in the future will provide efficient and crucial information to the decision makers and emergency agents to mitigate any disaster posed by natural hazards.

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A study on Average CN Estimation in River Basin using Satellite Data

  • Kwon, Bong-kyum;Jo, Myung-Hee;Ahn, Seung-Sep;Kiyoshi, Yamada
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.499-499
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    • 2002
  • The goal of this study is to apply and evaluate the precipitation outflow in river basin using satellite data and GIS for proposing the efficient watershed management method. Not only precipitation outflow data but also various spatial data such as digital map, soil map, geologic map and multi-temporal TM images were used. Using landcover classification result and soil map were applied to estimate the average CN. The CN value of 63.37 by SCS method was produced in AMC-2 condition otherwise the result of direct estimation with observation method was 63 CN value. The relative error of two results was 0.59%. It can be possible to apply the satellite data for precipitation outflow analysis. For more accurate and credible analysis of this, the more multi-temporal satellite and real observation data will be needed.

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Low-Resolution Wind Mapping For Estimation of Wind Resource Potential (풍력자원 잠재량 산출을 위한 저해상도 바람지도 구축)

  • Kim, Hyun-Goo;Jang, Moon-Seok;Kyong, Nam-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.307-308
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    • 2006
  • The national goal of wind energy dissemination has to be determined rationally based on technically available wind resource potential. For a reliable and scientific estimation or wind resource potential, a wind map is requisite. This paper presents the national wind map of Korea established by numerical wind simulation. Prediction accuracy of the low-resolution wind map is Improved by nudging QuikSCAT data and is validated by comparing with marine buoy beacon and met-mast measurements. Therefore, quantification of national wind resource potential is now possible and is anticipating to be utilized as a core index for policy and strategy building of wind energy dissemination and technology development.

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Depth Map Refinement using Segment Plane Estimation (세그멘트 평면 추정을 이용한 깊이 지도 개선)

  • Jung, Woo-Kyung;Han, Jong-Ki
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2020.07a
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    • pp.286-287
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    • 2020
  • Depth map is the most common way of expressing 3D space in immersive media. In this paper, we propose a post-processing method to improve the quality of depth map. In proposed method, a depth map is divided into segments, and the plane of each segment estimated using RANSAC. In order to increase the accuracy of the RANSAC process, we apply matching reliability of each pixel in depth map as a weighting factor.

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