• Title/Summary/Keyword: Shadow analysis

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Shadow Detection and Correction Method for Urban Area using KOMPSAT-3 Image (KOMPSAT-3 영상을 활용한 도심지 그림자 영역의 탐지 및 보정 방법)

  • Park, Sung-Hwan;Lee, Gyu-Seok;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.33 no.6_3
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    • pp.1197-1213
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    • 2017
  • This study was carried out to correct shadow area in urban area on KOMPSAT-3 satellite image. For this study, we analyzed characteristics of the shadow area represented by artificial structures in urban area. The proposed shadow correction method divides shadow area into umbra and penumbra areas according to intensity of darkness. The umbra area was detected through the histogram analysis and the statistical method of the NIR image, and then penumbra area and the sunlit area were detected from around the detected umbra area. The correction of the detected umbra and penumbra area were performed by applying the linear correlation correction method. As a result, it was confirmed that the proposed shadow correction method was visually performed well. Quantitative analysis was performed through profile analysis. It is proved that proposed method is useful for shadow area correction.

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.

Shadow Techniques in Real-time Hatching Rendering (실시간 해칭 렌더링에서 그림자 기법)

  • Kim, Chan-Soo;Kim, Dae-Myung
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.806-810
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    • 2006
  • The research of computer graphics is divided into two parts of photorealistic rendering and non-photorealistic rendering. The purpose of non-photo realistic rendering is to make image like cartoon, water-color, hatching etc. In this paper, we study for real-time hatching rendering and shadow techniques and we combine two techniques to make real-time hatching shadow. In shadow techniques we apply projected texture shadow to hatching rendering. Eventually, we introduce natural real-time hatching shadow through comparison and analysis.

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Calibration of NDVI Error at Shadow Areas with GRABS : Focused on Cheong City (GRABS 이용한 그림자 영역에서의 정규식생지수의 오차보정 : 청주시를 대상으로)

  • Ban, Yong-Un;Na, Sang-Il;Lee, Tae-Ho
    • Journal of Environmental Impact Assessment
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    • v.19 no.3
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    • pp.297-305
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    • 2010
  • This study has intended to analyze the nature of the errors that occur as a result of shadows during the process of NDVI calculation using high-resolution satellite images of Cheongju City, in order to calibrate such errors, and to verify the results. This study has calibrated the shadow errors by utilizing the relationship between the Greenness above Bare Soil (GRABS) calculated through Tasseled-Cap transformation and the original NDVI. To verify the accuracy of the results, this study has compared the shadow area extracted by the difference between before and after calibration of NDVI, with the original shadow area. The NDVI value converged on the value of -1.0, representing water, because shadow areas could not accept the reflection value from each band. However, after performing Tasseled-Cap transformation, the NDVI of shadow areas that had converged on -1.0 prior to calibration had increased to a level similar to the NDVI of neighboring areas. In addition, the average NDVI in general had increased from -0.08 to -0.01. Finally, the shadow area drawn out was almost matched to the original one, meaning that the NDVI calibration method employed turned out to be highly accurate in extracting shadow areas.

Shadow Extraction of Urban Area using Building Edge Buffer in Quickbird Image (건물 에지 버퍼를 이용한 Quickbird 영상의 도심지 그림자 추출)

  • Yeom, Jun-Ho;Chang, An-Jin;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.2
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    • pp.163-171
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    • 2012
  • High resolution satellite images have been used for building and road system analysis, landscape analysis, and ecological assessment for several years. However, in high resolution satellite images, shadows are necessarily cast by manmade objects such as buildings and over-pass bridges. This paper develops the shadow extraction procedures in urban area including various land-use classes, and the extracted shadow areas are evaluated by a manually digitized shadow map. For the shadow extraction, the Canny edge operator and the dilation filter are applied to make building edge buffer area. Also, the object-based segmentation was performed using Gram-Schmitt fusion image, and spectral and spatial parameters are calculated from the segmentation results. Finally, we proposed appropriate parameters and extraction rules for the shadow extraction. The accuracy of the shadow extraction results from the various assessment indices is 80% to 90%.

Types and Expressive Characteristics of the Chinese Shadow Puppetry Costumes, Yingxi (중국 산시성 피영극 복식의 유형 및 표현 특징)

  • Suh, Seunghee;Zhang, Qian
    • Journal of Fashion Business
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    • v.26 no.2
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    • pp.110-128
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    • 2022
  • The purpose of this study was to analyze the expressive characteristics of Chinese shadow puppetry costumes. Literature study and case analysis were conducted using books, research papers, and materials from the Xi'an shadow puppetry museum. Based on the Chinese traditional costumes, the shape characteristics are utilized with the intaglio and embossing techniques, and the complex and unnecessary details are omitted to express the costume image in a characteristic and simple manner. Second, colour was used according to the traditional Chinese symbolic colour concept, and the brighter the colour, the higher the role's status. The colour was also used to express identity and character. In addition, relatively vivid and highly saturated colours were used for the transparent effect of the shadow puppetry. Third, a role's status is indicated by the density and completeness of the patterns; the higher the role's status, the more complex and sophisticated the patterns, and the lower the status, the simpler the patterns or no patterns are used. Fourth, the faith for blessing expressed in the shadow puppetry is a representative folk auspicious culture. The repertoire of the shadow puppetry and the patterns on the costumes worn by the puppets, express the culture in an implicit way to symbolize the meaning of auspicious things.

Specimen Preparation for Scanning Electron Microscope Using a Converted Sample Stage

  • Kim, Hyelan;Kim, Hyo-Sik;Yu, Seungmin;Bae, Tae-Sung
    • Applied Microscopy
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    • v.45 no.4
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    • pp.214-217
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    • 2015
  • This study introduces metal coating as an effective sample preparation method to remove charge-up caused by the shadow effect during field emission scanning electron microscope (FE-SEM) analysis of dynamic structured samples. During a FE-SEM analysis, charge-up occurs when the primary electrons (input electrons) that scan the specimens are not equal to the output electrons (secondary electrons, backscattered electrons, auger electrons, etc.) generated from the specimens. To remove charge-up, a metal layer of Pt, Au or Pd is applied on the surface of the sample. However, in some cases, charge-up still occurs due to the shadow effect. This study developed a coating method that effectively removes charge-up. By creating a converted sample stage capable of simultaneous tilt and rotation, the shadow effect was successfully removed, and image data without charge-up were obtained.

Performance Analysis of Zonotope Shadow Matching Algorithm According to Various Urban Environments (다양한 도심 환경에 따른 ZSM 알고리즘의 성능 분석)

  • Sanghyun Kim;Jiwon Seo
    • Journal of Positioning, Navigation, and Timing
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    • v.13 no.3
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    • pp.215-220
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    • 2024
  • In urban areas, signals can be blocked and reflected by buildings, reducing the reliability of global navigation satellite systems (GNSS). To address this, the zonotope shadow matching (ZSM) algorithm has been proposed to estimate the set-valued receiver position by calculating the GNSS shadow based on the zonotope. However, the existing study only analyzed the performance of ZSM in dense urban areas where GNSS shadows occur frequently, and the performance analysis in various urban environments was insufficient. Therefore, in this paper, we analyzed the performance of the ZSM algorithm in four urban environments with different characteristics. The results showed that the receiver position estimation performance of ZSM was relatively poor in environments where buildings were not densely populated, and the performance of ZSM was shown to be effective in urban environments with narrow roads and tall buildings.

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.

A Longitudinal Study on the Effect of the Application Usage Period on the Change of Digital Shadow Work Type: Focused on LBS-based Help Apps Service (애플리케이션 사용자의 사용기간이 디지털그림자노동의 유형 변화에 미치는 영향에 대한 종단 연구: LBS 기반 도와줘 앱 서비스를 중심으로)

  • Jung-Sik, Song;Woong-Kyu, Lee;Byeong Hoon, Lee;Joon, Koh
    • Journal of Information Technology Services
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    • v.21 no.6
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    • pp.91-116
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    • 2022
  • This research shows how the perception of digital shadow work varies depending on the user's period of use of digital services in applications, which are key areas of digital services. The purpose of this research is to investigate how the digital shadow work type changes over time. This research adopted a qualitative research method for location-based service "help application" users and examined the change in perception from the app service acceptance stage to the app service continuous use stage with two-times interviews of ten users by a longitudinal research design. This study conducted a longitudinal analysis focusing on how digital shadow work occurs in the application subscription process, exploring phenomenologically how the type changes throughout the process over time.