• Title/Summary/Keyword: 캘리브레이션

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Comparison of Spatial Small Area Estimators Based on Neighborhood Information Systems (이웃정보시스템을 이용한 공간 소지역 추정량 비교)

  • Kim, Jeong-Suk;Hwang, Hee-Jin;Shin, Key-Il
    • The Korean Journal of Applied Statistics
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    • v.21 no.5
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    • pp.855-866
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    • 2008
  • Recently many small area estimation methods using the lattice data analysis have been studied and known that they have good performances. In the case of using the lattice data which is mainly used for small area estimation, the choice of better neighborhood information system is very important for the efficiency of the data analysis. Recently Lee and Shin (2008) compared and analyzed some neighborhood information systems based on GIS methods. In this paper, we evaluate the effect of various neighborhood information systems which were suggested by Lee and Shin (2008). For comparison of the estimators, MSE, Coverage, Calibration, Regression methods are used. The number of unemployment in Economic Active Population Survey(2001) is used for the comparison.

Fast Vehicle Detection based on Haarlike and Vehicle Tracking using SURF Method (Haarlike 기반의 고속 차량 검출과 SURF를 이용한 차량 추적 알고리즘)

  • Yu, Jae-Hyoung;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.1
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    • pp.71-80
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    • 2012
  • This paper proposes vehicle detection and tracking algorithm using a CCD camera. The proposed algorithm uses Haar-like wavelet edge detector to detect features of vehicle and estimates vehicle's location using calibration information of an image. After that, extract accumulated vehicle information in continuous k images to improve reliability. Finally, obtained vehicle region becomes a template image to find same object in the next continuous image using SURF(Speeded Up Robust Features). The template image is updated in the every frame. In order to reduce SURF processing time, ROI(Region of Interesting) region is limited on expended area of detected vehicle location in the previous frame image. This algorithm repeats detection and tracking progress until no corresponding points are found. The experimental result shows efficiency of proposed algorithm using images obtained on the road.

Computer Vision Based Efficient Control of Presentation Slides (컴퓨터비전에 기반한 효율적인 프리젠테이션 슬라이드 제어)

  • 박정우;석민수;이준호
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.4
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    • pp.232-239
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    • 2003
  • This paper discusses the design and implementation of a human-oriented interface based on computer vision that efficiently controls presentation slides. The user does not have to be confined to a keyboard or mouse any more, and can move around more freely because slides for presentation can be up and down using a general laser pointer that is used for presentation. Regions for virtual buttons are set on the slide so that the user can conveniently point the buttons using the laser pointer. We have proposed a simple and efficient method that computes the button areas in the image without complicated calibration. The proposed method has been implemented based on Microsoft PowerPoint ; moreover it can be applied to other PowerPoint-like presentation softwares. Our method for human-centered slide control enables the user to give audiences a more interactive presentation in a natural way.

Method for the Measurement of Dissolved Oxygen in a Cell Culture Microchannel Using Oxygen-Sensitive Luminescence (산소 민감 발광 염료를 이용한 마이크로 채널 내에서 배양되는 세포 주변의 산소 농도 측정)

  • Lee, Seung-Youl;Jin, Song-Wan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.5
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    • pp.533-538
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    • 2012
  • In this study, we used an $O_2$-sensitive luminescent dye to measure the $O_2$ concentration of culture media around HeLa cells cultured in a microchannel. $[Ru(bpy)_3]^{2+}$, which dissolves easily in water and which has no phototoxic effect, was used as the $O_2$-sensitive dye. The ratiometric sensing method was applied by introducing calcein as the $O_2$-insensitive dye, in order to overcome the disadvantages of intensity-based sensing. By performing calibration with an amperometric $O_2$ sensor, we could calculate the exact concentration of $O_2$ in the culture media. We applied this technique to measure the $O_2$ concentration around the cultured cells in the microchannel. As expected, the $O_2$ concentration gradually decreased as the cells moved farther away from the channel. This method is expected to be applicable to the investigation of hypoxia, which occurs commonly in scaffolds.

The Stereo Camera Measurement of Point Cloud on 3D Object and the Calculation of Volume Based on Irregular Triangular Mesh (스테레오 카메라와 측정에 의한 3D 대상체 포인트 클라우드의 불규칙 삼각 매싱 기반 체적 계산)

  • Lee, Young-Dae;Cho, Sung-Youn;Kim, Kyung;Lee, Dong-Gyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.4
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    • pp.153-159
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    • 2012
  • For the construction of safe and clear urban environment, it is necessary that we identify the rubbish waste volume and we know the accuracy volume. In this paper, we proposed the algorithm computes the waste volume periodically for the way of waste repository standard. After stereo camera calibration, we obtained the point cloud on the surface of the object and took this as the input of the calculation algorithm of the object volume. We proposed the volume calculation algorithms based on the non-uniform triangular meshing methods and verified the validity of the algorithm through simulation and real experiments. The proposed algorithm can be used not only as the volume calculation of the waste repository but also as the general volume calculation of a three dimensional object.

Public Transport Network Connectivity using GIS-based Space Syntax (GIS 기반 Space Syntax를 이용한 대중교통 접근성)

  • Jun, Chul-Min
    • Journal of Korea Spatial Information System Society
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    • v.9 no.3
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    • pp.25-33
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    • 2007
  • The local governments of major cities in Korea are giving focus on public transportation to reduce congestion and improve accessibility in city areas. In this regards, the proper measurement of accessibility is now a key policy requirement for reorganizing the public transport network. Public transport routing problems, however, are considered to be highly complicated since a multi-mode travel generates different combinations of accessibility. While most of the previous research efforts on measuring transport accessibility are found at zone-levels, an alternative approach at a finer scale such as bus links and stops is presented in this study. We proposes a method to compute the optimal route choice of origin-destination pairs and measure the accessibility of the chosen modes combination based on topological configuration. The genetic algorithm is used for the computation of the journey paths, whereas the space syntax theory is used for the accessibility. This study used node-link data in GIS instead of axial lines which are manually drawn in space syntax. The resulting accessibilities of bus stops are calibrated by O-D survey data and the proposed process is tested on a CBD of Seoul.

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Study on the Brightness Temperature Measurement in the Human Body Using Millimeter-wave Radiometer (밀리미터파 라디오미터를 이용한 인체의 내부 밝기온도 측정에 관한 연구)

  • Jung, Min Kyoo;Kim, Tae Hun;Nah, Seung Wook
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.5
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    • pp.163-167
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    • 2016
  • We have developed a millimeter-wave radiometer system for applications in the fields of medical imaging. In this paper, we introduced the brightness temperature measurement in the human body using Millimeter-wave Radiometer. Calibration of sensitivity of the radiometer system is essential to measure equivalent temperature (brightness temperature) of objects. We have developed, as a calibration source, a new type of black body for the millimeter wave region with temperature control capability. The system noise figure and temperature sensitivity of the system measured using the blackbody are 3.3 dB and 0.1 K, respectively. The brightness temperature of human body through clothes was measured to be around $38^{\circ}$[C].

Color Correction for Uniformity Illumination using Multispectral Relighting (멀티스펙트럴 재조명을 이용한 균일 조명 색상 보정)

  • Sim, Kyudong;Park, Jong-Il
    • Journal of Broadcast Engineering
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    • v.22 no.2
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    • pp.207-213
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    • 2017
  • In order to accurately perform multispectral imaging using a multiplexed illumination, intensity of illumination in a scene must be uniform. For image acquisition that requires accurate color information, even if not multispectral imaging, the illumination information must be accurate, and a flat light source or illumination calibration is performed for accurate illumination characteristics. In this paper, we propose a method of color correction to uniformly illuminate an image with non-uniform illumination intensity. The proposed method uses multispectral imaging instead of illumination calibration for color correction. First of all, we perform multispectral imaging with two images obtained from non-uniformity illumination to acquire spectral reflectance. The obtained reflection spectrum is relit as the illumination characteristic of the image obtained from general planar light such as fluorescent light or sunlight. By comparing the image obtained by relighting with the uniformly illuminated image, the non-uniformity of the illumination is confirmed, and the color correction is performed as the image obtained from the uniform image. It is expected that the experimental results will confirm whether the non-uniformity of the illumination is uniformly corrected and reduce the restriction of illumination in obtaining the color information of the image.

A Study on Gaze Tracking Based on Pupil Movement, Corneal Specular Reflections and Kalman Filter (동공 움직임, 각막 반사광 및 Kalman Filter 기반 시선 추적에 관한 연구)

  • Park, Kang-Ryoung;Ko, You-Jin;Lee, Eui-Chul
    • The KIPS Transactions:PartB
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    • v.16B no.3
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    • pp.203-214
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    • 2009
  • In this paper, we could simply compute the user's gaze position based on 2D relations between the pupil center and four corneal specular reflections formed by four IR-illuminators attached on each corner of a monitor, without considering the complex 3D relations among the camera, the monitor, and the pupil coordinates. Therefore, the objectives of our paper are to detect the pupil center and four corneal specular reflections exactly and to compensate for error factors which affect the gaze accuracy. In our method, we compensated for the kappa error between the calculated gaze position through the pupil center and actual gaze vector. We performed one time user calibration to compensate when the system started. Also, we robustly detected four corneal specular reflections that were important to calculate gaze position based on Kalman filter irrespective of the abrupt change of eye movement. Experimental results showed that the gaze detection error was about 1.0 degrees though there was the abrupt change of eye movement.

A Study on Underwater-Pipe Video Image Mosaicking using Digital Photogrammetry (수치사진측량을 이용한 수중 파이프 비디오 모자익 영상 제작에 관한 연구)

  • Kang, Jin-A;Kwon, Kwang-Seok;Kim, Byung-Guk;Oh, Yoon-Seuk
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.150-160
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    • 2008
  • The present domestic underwater and ocean facilities management depends on analysis with the naked eye. This study performs quantitative analysis to improve conventional methods, analyze spatial situation of underwater facilities. This research is divided into two steps; underwater image distortion correction and image mosaic step. First, underwater image distortion correction step is for the production of underwater target, calculates the correction parameters, and then developed the method that convert the original image point to whose distortion is corrected. Second step is for the obtaining pipe images installed in the underwater, corrects the distortion, and then transforms a coordinates of the correction pipe image. After coordinate transformation, we make the mosaic image using the singularities. As a result, when we measure the distance between pipe and underwater ground and compare with calculation value on mosaic image, it is showed that RMSE is 0.3cm.

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