• Title/Summary/Keyword: Projection Map

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A GIS-based Analysis on Geometric Distortions in Historical Maps: A Preliminary Case Study of Daedongyeojido ('The Great Map of Korea') (고지도의 왜곡 양상에 대한 GIS-기반 연구: 대동여지도를 사례로 한 시론적 분석)

  • Lee, Sang-Il;Cho, Daeheon
    • Journal of the Korean Geographical Society
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    • v.49 no.3
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    • pp.438-455
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    • 2014
  • This study aims at providing a set of viable answers regarding the projection and cartographic scale of Daedongyeojido through a GIS-based planimetric accuracy analysis. Both global and local analyses were undertaken in the use of an analytical tool, MapAnalyst. The main results from the global analysis are threefold. First, the overall cartographic scale turned out to be between 1:158,000 and 1:162,000. Second, the rotation angles were between $2^{\circ}$ and $3^{\circ}$, and the equidistant cylindrical projection reported the smallest value. Third, in terms of position accuracy, the conformal cylindrical projection showed a best fit to the map. A local analysis was undertaken for the conformal cylindrical and equidistant azimuthal projections and its main results are threefold. First, the largest distortions in terms of the displacement vectors and distortion grid were found in the northern borderlands. Second, from the isoline maps of scales, it was acknowledged that local scales between 1:170,000 and 1:175,000 were found around the middle part of the Korean peninsula centered on Seoul. As away from the region to the north-south direction, increasingly larger scales were distributed, while the smallest ones were found in the western and eastern edges of the peninsula. Third, from the isoline maps of rotation, it was known that areas west of a northernmost city (Junggangjin) were substantially rotated to the west, while ones east of it to the east. For a more sophisticated analysis, some need to be done to have a larger set of control points, a better way of postulating the map projection, and a more advanced set of techniques for a local analysis.

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Video Object Extraction Using Contour Information (윤곽선 정보를 이용한 동영상에서의 객체 추출)

  • Kim, Jae-Kwang;Lee, Jae-Ho;Kim, Chang-Ick
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.1
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    • pp.33-45
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    • 2011
  • In this paper, we present a method for extracting video objects efficiently by using the modified graph cut algorithm based on contour information. First, we extract objects at the first frame by an automatic object extraction algorithm or the user interaction. To estimate the objects' contours at the current frame, motion information of objects' contour in the previous frame is analyzed. Block-based histogram back-projection is conducted along the estimated contour point. Each color model of objects and background can be generated from back-projection images. The probabilities of links between neighboring pixels are decided by the logarithmic based distance transform map obtained from the estimated contour image. Energy of the graph is defined by predefined color models and logarithmic distance transform map. Finally, the object is extracted by minimizing the energy. Experimental results of various test images show that our algorithm works more accurately than other methods.

Some Properties of Product Smooth Fuzzy Topological Spaces

  • Park, Jin-Won
    • Journal of the Korean Institute of Intelligent Systems
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    • v.9 no.6
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    • pp.615-620
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    • 1999
  • We will investigate some properties of product smooth fuzzy topological spaces. We will show that a projection map in product smooth fuzzy topological spaces need not be a fuzzy open map. Furthermore a slice need not be homeomorphic to the coordinate spance which is parallel to it.

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Effective Sonar Grid map Matching for Topological Place Recognition (위상학적 공간 인식을 위한 효과적인 초음파 격자 지도 매칭 기법 개발)

  • Choi, Jin-Woo;Choi, Min-Yong;Chung, Wan-Kyun
    • The Journal of Korea Robotics Society
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    • v.6 no.3
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    • pp.247-254
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    • 2011
  • This paper presents a method of sonar grid map matching for topological place recognition. The proposed method provides an effective rotation invariant grid map matching method. A template grid map is firstly extracted for reliable grid map matching by filtering noisy data in local grid map. Using the template grid map, the rotation invariant grid map matching is performed by Ring Projection Transformation. The rotation invariant grid map matching selects candidate locations which are regarded as representative point for each node. Then, the topological place recognition is achieved by calculating matching probability based on the candidate location. The matching probability is acquired by using both rotation invariant grid map matching and the matching of distance and angle vectors. The proposed method can provide a successful matching even under rotation changes between grid maps. Moreover, the matching probability gives a reliable result for topological place recognition. The performance of the proposed method is verified by experimental results in a real home environment.

Preprocessing Technique for Improving Action Recognition Performance in ERP Video with Multiple Objects (다중 객체가 존재하는 ERP 영상에서 행동 인식 모델 성능 향상을 위한 전처리 기법)

  • Park, Eun-Soo;Kim, Seunghwan;Ryu, Eun-Seok
    • Journal of Broadcast Engineering
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    • v.25 no.3
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    • pp.374-385
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    • 2020
  • In this paper, we propose a preprocessing technique to solve the problems of action recognition with Equirectangular Projection (ERP) video. The preprocessing technique proposed in this paper assumes the person object as the subject of action, that is, the Object of Interest (OOI), and the surrounding area of the OOI as the ROI. The preprocessing technique consists of three modules. I) Recognize person object in the image with object recognition model. II) Create a saliency map from the input image. III) Select subject of action using recognized person object and saliency map. The subject boundary box of the selected action is input to the action recognition model in order to improve the action recognition performance. When comparing the performance of the proposed preprocessing method to the action recognition model and the performance of the original ERP image input method, the performance is improved up to 99.6%, and the action is obtained when only the OOI is detected. It can also see the effects of related video summaries.

Fully Automatic Liver Segmentation Based on the Morphological Property of a CT Image (CT 영상의 모포러지컬 특성에 기반한 완전 자동 간 분할)

  • 서경식;박종안;박승진
    • Progress in Medical Physics
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    • v.15 no.2
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    • pp.70-76
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    • 2004
  • The most important work for early detection of liver cancer and decision of its characteristic and location is good segmentation of a liver region from other abdominal organs. This paper proposes a fully automatic liver segmentation algorithm based on the abdominal morphology characteristic as an easy and efficient method. Multi-modal threshold as pre-processing is peformed and a spine is segmented for finding morphological coordinates of an abdomen. Then the liver region is extracted using C-class maximum a posteriori (MAP) decision and morphological filtering. In order to estimate results of the automatic segmented liver region, area error rate (AER) and correlation coefficients of rotational binary region projection matching (RBRPM) are utilized. Experimental results showed automatic liver segmentation obtained by the proposed algorithm provided strong similarity to manual liver segmentation.

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Super Resolution Algorithm Based on Edge Map Interpolation and Improved Fast Back Projection Method in Mobile Devices (모바일 환경을 위해 에지맵 보간과 개선된 고속 Back Projection 기법을 이용한 Super Resolution 알고리즘)

  • Lee, Doo-Hee;Park, Dae-Hyun;Kim, Yoon
    • KIPS Transactions on Software and Data Engineering
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    • v.1 no.2
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    • pp.103-108
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    • 2012
  • Recently, as the prevalence of high-performance mobile devices and the application of the multimedia content are expanded, Super Resolution (SR) technique which reconstructs low resolution images to high resolution images is becoming important. And in the mobile devices, the development of the SR algorithm considering the operation quantity or memory is required because of using the restricted resources. In this paper, we propose a new single frame fast SR technique suitable for mobile devices. In order to prevent color distortion, we change RGB color domain to HSV color domain and process the brightness information V (Value) considering the characteristics of human visual perception. First, the low resolution image is enlarged by the improved fast back projection considering the noise elimination. And at the same time, the reliable edge map is extracted by using the LoG (Laplacian of Gaussian) filtering. Finally, the high definition picture is reconstructed by using the edge information and the improved back projection result. The proposed technique removes effectually the unnatural artefact which is generated during the super resolution restoration, and the edge information which can be lost is amended and emphasized. The experimental results indicate that the proposed algorithm provides better performance than conventional back projection and interpolation methods.

ANALYSIS OF THE KOREAN CELESTIAL PLANISPHERE: CH'ON-SANG-YUL-CHA-BUN-YA-JI-DO

  • PARK CHANGBOM
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.433-437
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    • 1996
  • We have analyzed the content of the Korean stone star chart. Ch'on-Sang-Yul-Cha-Bun-Ya-Ji-Do(here-after Ch'on-Sang-Do). In the star map we have found 1468 stars, 4 more than the Chinese star catalog Bo-Chun-Ga. The four extra stars form a constellation, Jong Dae Boo. The map projection law used in the star chart is found to be the polar equtorial and equidistance projection. The linear distance of an object on Ch'on-Sang-Do from the center is linearly proportional to the north polar angular distance. We have found from a statistical analysis that most stars with declination lower than 50 are at positions representing the epoch of around the first century. On the other hand, stars near the north pole with declination higher than 50 are at the epoch of about 1300, which is close to the time the chart was engraved. This implies that the original Ko-Gu-Rye Dynasty's star chart has been revised by astronomers of Cho-Sun Dynasty. We have also shown that stars on Ch'on-Sang-Do are engraved in such a way that their area is linearly proportional to the visual magnitude.

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A New Method for Color Feature Representation of Color Image in Content-Based Image Retrieval Projection Maps

  • Kim, Won-Ill
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.9 no.2
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    • pp.73-79
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    • 2010
  • The most popular technique for image retrieval in a heterogeneous collection of color images is the comparison of images based on their color histogram. The color histogram describes the distribution of colors in the color space of a color image. In the most image retrieval systems, the color histogram is used to compute similarities between the query image and all the images in a database. But, small changes in the resolution, scaling, and illumination may cause important modifications of the color histogram, and so two color images may be considered to be very different from each other even though they have completely related semantics. A new method of color feature representation based on the 3-dimensional RGB color map is proposed to improve the defects of the color histogram. The proposed method is based on the three 2-dimensional projection map evaluated by projecting the RGB color space on the RG, GB, and BR surfaces. The experimental results reveal that the proposed is less sensitive to small changes in the scene and that achieve higher retrieval performances than the traditional color histogram.

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Distortions of Spherical Data in the Wavenumber Domain

  • Kim, Jeong-Woo;Lee, Dong-Cheon
    • Korean Journal of Remote Sensing
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    • v.18 no.3
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    • pp.171-179
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    • 2002
  • Sampling rates become inconsistent when spatial data in the spherical coordinate are resampled with respect to latitudinal or longitudinal degree for mathematical processes such as Fourier Transform, and this results in distortions of the processed data in the wavenumber domain. These distortions are more evident in the polar regions. An example is presented to show such distortions during the recovery process of free-air gravity anomalies from ERS-1 satellite radar altimeter data from the Barents Sea in the Russian Arctic, and a method is presented to minimize the distortion using the Lambert Conformal Conic map projection. This approach was found to enhance the free-air gravity anomalies in both data and wavenumber domains.