• Title/Summary/Keyword: 가림

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Evaluation of Marker Images based on Analysis of Feature Points for Effective Augmented Reality (효과적인 증강현실 구현을 위한 특징점 분석 기반의 마커영상 평가 방법)

  • Lee, Jin-Young;Kim, Jongho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.49-55
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    • 2019
  • This paper presents a marker image evaluation method based on analysis of object distribution in images and classification of images with repetitive patterns for effective marker-based augmented reality (AR) system development. We measure the variance of feature point coordinates to distinguish marker images that are vulnerable to occlusion, since object distribution affects object tracking performance according to partial occlusion in the images. Moreover, we propose a method to classify images suitable for object recognition and tracking based on the fact that the distributions of descriptor vectors among general images and repetitive-pattern images are significantly different. Comprehensive experiments for marker images confirm that the proposed marker image evaluation method distinguishes images vulnerable to occlusion and repetitive-pattern images very well. Furthermore, we suggest that scale-invariant feature transform (SIFT) is superior to speeded up robust features (SURF) in terms of object tracking in marker images. The proposed method provides users with suitability information for various images, and it helps AR systems to be realized more effectively.

Comparison of Growth Characteristics and Ginsenoside Contents of 3-Year-Old Ginseng (Panax ginseng C. A. Meyer) by Drainage Class and Shade Material in Paddy Soil (논토양에서 해가림 유형별 3년생 인삼의 생육과 진세노사이드함량 비교)

  • Lee, Sung-Woo;Kim, Gum-Sook;Hyun, Dong-Yun;Kim, Yong-Burm;Yeon, Byeong-Yeol;Kang, Seung-Won;Kim, Young-Churl
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.4
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    • pp.390-396
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    • 2009
  • To select optimal shade material in paddy soil, growth characteristics and ginsenoside contents were investigated in new cultivar, 'Cheonpoong' of three-year-old ginseng cultured under three kinds of shade materials such as three-layered blue and one-layered black PE (polyethylene) net (TBPN), blue PE sheet (BPSS), and aluminium-coated PE sheet (APSS). The order of light transmission ratio and air temperature by shade materials were BPSS > APSS > TBSB among three shade materials. Average soil water tension in PDC and IDC was 64 mbar (absolute soil moisture, 25%) and 123 mbar (absolute soil moisture, 17%), respectively, and soil water tension in IDC was changed more distinctly than that of PDC by season and shade materials. Yield in PDC was distinctly decreased more than that in IDC because of the increase of discolored-leaf and rusted-root ratio. BPSS and TBPN among three shade materials were the most effective on the increase of yield in PDC and IDC, respectively. Ratio of rusty-colored root showed not significant difference by drainage class and shade materials. Contents of panaxatriol ginsenoside (Rg1, Re and Rf) were decreased in PDC, while it of panaxadiol ginsenoside (Rb1, Rc and Rd) were increased in IDC. Total ginsenoside contents of IDC was distinctly higher than that of PDC, and BPSS showed the highest contents among three shade materials regardless of poorly and imperfectly drainage class.

The Study of Relationship Between Hyperopic Amblyopia, Anisometropic Power and Astigmatism (원시성약시와 굴절부등, 난시와의 관계 연구)

  • Park, Hyun-Ju
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.3
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    • pp.137-142
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    • 2007
  • The purpose of this study was to investigate sole effect of therapy of spectacles correction on the refractive amblyopia. Spectacles were prescribed to give the same effect as the occlusion therapy undercorrecting in the case of hyperopia, and effectiveness of the therapy was compared with occlusion therapy without additional prescription. The results can be summarized as follows: 1. The higher anisometropic power was the lower initial visual acuity was. 2. Anisometropic power did not influence final visual acuity. 3. The latter beginning time of therapy was the higher astigmatism was. 4. Therapy of spectacles correction on the hyperopic amblyopia was quite effective.

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A People Counting Technique for Video Surveillance and Monitoring(VSAM) Systems (비디오에 의한 감시 및 관측(VSAM) 시스템을 위한 사람의 계수기법)

  • Do, Yong-Tae
    • Journal of Sensor Science and Technology
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    • v.11 no.1
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    • pp.28-38
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    • 2002
  • People are important targets for video surveillance and monitoring(VSAM) but difficult to be analyzed. In this paper, a technique to count people in image sequences is dealt as a prerequisite procedure for automatic tracking and behaviour analysis. A group of people is divided at local minima of the line connecting the highest pixels on the binary image of the people extracted from the image taken by a stationary video camera. As the properties of the divided regions vary according to the relative positions of the people in a group, different states are assigned for the completely occluded, partially occluded, completed separated individual, and wrongly divided regions. By analyzing the transition of the states of divided regions, the number of people on the site monitored is estimated. The technique is checked in real experimental situations.

Effect of Light Transmittance Control on the Growth Status of Aerial Parts during the Growing Season of Panax ginseng (생육시기별 광량조절이 인삼의 지상부 생육에 미치는 영향)

  • Cheon, Seong-Ki;Lee, Tae-Su;Yoon, Jong-Hyuk;Lee, Sung-Sik
    • Journal of Ginseng Research
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    • v.27 no.4
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    • pp.202-206
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    • 2003
  • This study was conducted to compare the growth status of aerial parts, photosynthesis and microclimate between fixing light transmittance (Control) and changing light transmittance (C.L.T.) during ginseng growing seasons. Control showed 8% light transmittance rate during growing seasons. But C.L.T. showed 18% light transmittance rate during early (April-June) and late growth stage (September-October) and 6% light transmittance rate middle growth stage(July-August). Air temperature, leaking water rate and soil water content of C.L.T. was higher than those of control during early and late growth stage. But Air temperature, leaking water rate and soil water content of C.L.T was lower than those of control during middle growth stage C.L.T. exhibited superiority in survival ratio, stem diameter, stem length, L.A.I. and stem angle compared to control. Chlorophyll content of C.L.T. was lower than that of control but S.L.W., stomatal opening and photosynthetic rates of C.L.T. was higher than those of control. Also Alternaria blight disease and defoliation of C.L.T. was lower than those of control.