• Title/Summary/Keyword: shadow

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Extracting Shadow area and recovering of image (영상의 그림자 영역 경계 검출 및 복원 연구)

  • Choi, Yun-Woong;Jeon, Jae-Yong;Park, Jung-Nam;Cho, Gi-Sung
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.169-173
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    • 2007
  • Nowadays the aerial photos is using to get the information around our spatial environment and it increases by geometric progression in many fields. The aerial photos need in a simple object such as cartography and ground covey classification and also in a social objects such as the city plan, environment, disaster, transportation etc. However, the shadow, which includes when taking the aerial photos, makes a trouble to interpret the ground information, and also users, who need the photos in their field tasks, have restriction. This study, for removing the shadow, uses the single image and the image without the source of image and taking situation. Also, this study present clustering algorism based on HIS color model that use Hue, Saturation and Intensity, especially this study used I(intensity) to extract shadow area from image. And finally by filtering in Fourier frequency domain creates the intrinsic image which recovers the 3-D color information and removes the shadow.

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Fault detection of shadow mask by use of spatial filtering

  • Sakata, Masato;Kashiwagi, Kiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.251-256
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    • 1993
  • In KACC'91 and '92 conference, we proposed a method of automatically detecting the shape of the faulty holes in a shadow mask by use of CCD ca.mera and image data processing technic. In this method, two adjoining test areas from one image data. of the shadow mask are taken and comparing the shape of holes in these two areas, we can detect the faults in the shadow mask. In this paper, a method is described by use of spatial filtering of effectively finding the faulty holes from the difference image data between the two tested image data. The main role of the filter is to remove sampling errors occurring at the edge of the holes. And the second role is not only to find the existence of faulty holes but also exactly express the shape of faulty holes. Computer simulations and actual experiments with shadow masks have shown that this method of fault detection is very effective for practical use.

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Analysis of Microphonic Phenomenon for Shadow Mask in Flat TV by FEM (유한요소법에 의한 평면 TV 새도우마스크의 마이크로포닉 현상 해석)

  • Kim, Jung;Park, Soog-Kil;Kang, Bum-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.11
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    • pp.89-95
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    • 2002
  • A shadow mask inside the Braun tube of a TV is sustained by springs attached to the glass panel, its vibration cause the picture image to discolor, which is called the microphonic phenomenon. It is found that it results from resonance when the natural frequency of the shadow mask coincides with that of built-in speaker sound. This paper describes experimental and analytical investigations by using FEM on the vibration problem of the shadow mask assembly. The simulation scheme may be efficiently used to develop a new design for a large-screen flat TV.

Color Intensity Variation based Approach for Background Subtraction and Shadow Detection

  • Erdenebatkhaan, Turbat;Kim, Hyoung-Nyoun;Lee, Joong-Ho;Kim, Sung-Joon;Park, Ji-Hyung
    • 한국HCI학회:학술대회논문집
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    • 2007.02a
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    • pp.298-301
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    • 2007
  • Computational speed plays key role in background subtraction and shadow detection, because those are only preprocessing steps of a moving object segmentation, tracking and activity recognition. A color intensity variation based approach fastly detect a moving object and extract shadow in a image sequences. The moving object is subtracted from background using meanmax, meanmin thresholds and shadow is detected by decrease limit and correspondence thresholds. The proposed approach relies on the ability to represent shadow cast impact by offline experiment dataset on sub grouped RGB color space.

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Minimization of Shadow Zone for Hull Mounted Sonar (선체 고정형 소나의 음영 구역 최소화)

  • Lim, Se-Han;Han, Yun-Hoo;Jang, Chan-Joo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.2
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    • pp.211-217
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    • 2010
  • This paper introduces the Hull Mounted Sonar Vertical Scanning(HMS Verscan) technique to overcome the limitation of target detection in short range shadow zone. Numerical experiments were done with the HMS Verscan taking advantage of the vertical beamforming technique for two-dimension hydrospace(range-depth). For numerical experiments, ray model and high-frequency monostatic reverberation model were used. HMS Verscan increased a sound pressure level at the short range shadow zone through reflections at the sea surface and seafloor. Inclusion of the boundary scattering improved target detection due to the sound reflected into the shadow zone.

The Effects of the Electron Reflecting Layer Screen-printed with the Lead Tungsten Oxides on the Shadow Mask in CRT

  • Kim, Sang-Mun
    • Journal of the Korean Ceramic Society
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    • v.40 no.2
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    • pp.113-117
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    • 2003
  • To reduce the doming of the shadow mask due to thermal expansion and to prevent the color discrepancy, the electron reflecting layer with lead tungsten oxides on the electron gun side of shadow mask was formed by screen printing method and doming property was evaluated in CRT. First, the lead tungsten oxides were prepared by calcining the mixture of lead oxide and tungsten oxide above 600$^{\circ}C$. Second, the paste which has the anti-doming composition including the lead tungsten oxides was coated by screen-printing method. As a result, the doming of the shadow mask was reduced about from 30 to 45%.

Analysis of Post Cleaning Solution After Wet Cleaning of Shadow Mask Used in OLED Process (OLED공정에서 사용되는 섀도마스크의 습식 세정 후 세정표면 및 세정용액 분석에 관한 연구)

  • Cui, Yinhua;Pyo, Sung Gyu
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.4
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    • pp.7-10
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    • 2016
  • The post cleaning method for clean the shadow mask using in OLED (organic light emitting diode) emitter layer is always reforming. The cleaning solution and analysis method of shadow mask is still lack and not optimized. We use the simple and useful analytical method to determine the quantity and quality of organic and inorganic residue on surface of shadow mask. Finally analyze the cleaning solution using Raman spectroscopy efficiently.

Analysis of the Effect of Met Tower Shadow using Computational Fluid Dynamics (전산유체역학을 이용한 풍황탑 차폐효과 해석)

  • Kim, Taesung;Rhee, Huinam;Kim, Hyun-Goo
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.35.1-35.1
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    • 2011
  • When the wind speed is measured by the met-mast sensor it is distorted due to the shadow effect of tower. In this paper the tower shadow effect is analyzed by a computational fluid dynamics code. First three dimensional modeling and flow analysis of the met-mast system were performed. The results were compared with the available experimental wind-tunnel test data to confirm the validity of the meshes and turbulence model. Two-dimensional model was then developed based on the three-dimensional works and experimental data. 2D analysis for various Reynolds numbers and turbulence strengths were then performed to establish the tower shadow effect database, which can be utilized as correction factors for the measured wind energy.

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Role-Balance Based Multi-Secret Images Sharing using Boolean Operations

  • Chan, Chi-Shiang;Chou, Yung-Chen;Chen, Yi-Hui;Tsai, Yuan-Yu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.5
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    • pp.1785-1800
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    • 2014
  • In 2011, Chen and Wu proposed their method of sharing n secret images to n+1 shadow images through the concept of a Boolean-based Visual Secret Sharing (VSS) method. However, the shadow images produced by this method are not equally important. If the participant who owns an important shadow image does not want to cooperate with other participants, most secret images can not be reconstructed. In the proposed method, the relationship between the shadows images and secret images are designed in a circular way mostly. Each shadow image only relates to two secret images. This means that if one participant refuses to cooperate with other participants, there are only two secret images which can not be reconstructed. Moreover, our proposed method only needs to produce n shadow images and n secret images can be shared to them.

Midline enhancer activity of the short gastrulation shadow enhancer is characterized by three unusual features for cis-regulatory DNA

  • Shin, Dong-Hyeon;Hong, Joung-Woo
    • BMB Reports
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    • v.48 no.10
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    • pp.589-594
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    • 2015
  • The shadow enhancer of the short gastrulation (sog) gene directs its sequential expression in the neurogenic ectoderm and the ventral midline of the developing Drosophila embryo. Here, we characterize three unusual features of the shadow enhancer midline activity. First, the minimal regions for the two different enhancer activities exhibit high overlap within the shadow enhancer, meaning that one developmental enhancer possesses dual enhancer activities. Second, the midline enhancer activity relies on five Single-minded (Sim)-binding sites, two of which have not been found in any Sim target enhancers. Finally, two linked Dorsal (Dl)- and Zelda (Zld)-binding sites, critical for the neurogenic ectoderm enhancer activity, are also required for the midline enhancer activity. These results suggest that early activation by Dl and Zld may facilitate late activation via the noncanonical sites occupied by Sim. We discuss a model for Zld as a pioneer factor and speculate its role in midline enhancer activity.