• Title/Summary/Keyword: defective pixels

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A Study on Surface Defect Detection Model of 3D Printing Bone Plate Using Deep Learning Algorithm (딥러닝 알고리즘을 이용한 3D프린팅 골절합용 판의 표면 결함 탐지 모델에 관한 연구)

  • Lee, Song Yeon;Huh, Yong Jeong
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.2
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    • pp.68-73
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    • 2022
  • In this study, we produced the surface defect detection model to automatically detect defect bone plates using a deep learning algorithm. Bone plates with a width and a length of 50 mm are most used for fracture treatment. Normal bone plates and defective bone plates were printed on the 3d printer. Normal bone plates and defective bone plates were photographed with 1,080 pixels using the webcam. The total quantity of collected images was 500. 300 images were used to learn the defect detection model. 200 images were used to test the defect detection model. The mAP(Mean Average Precision) method was used to evaluate the performance of the surface defect detection model. As the result of confirming the performance of the surface defect detection model, the detection accuracy was 96.3 %.

Development of Agricultural Products Screening System through X-ray Density Analysis

  • Eunhyeok Baek;Young-Tae Kwak
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.4
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    • pp.105-112
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    • 2023
  • In this paper, we propose a new method for displaying colored defects by measuring the relative density with the wide-area and local densities of X-ray. The relative density of one pixel represents a relative difference from the surrounding pixels, and we also suggest a colorization of X-ray images representing these pixels as normal and defective. The traditional method mainly inspects materials such as plastics and metals, which have large differences in transmittance to the object. Our proposed method can be used to detect defects such as sprouts or holes in images obtained by an inspection machine that detects X-rays. In the experiment, the products that could not be seen with the naked eye were colored with pests or sprouts in a specific color so that they could be used in the agricultural product selection system. Products that are uniformly filled with a single ingredient inside, such as potatoes, carrots, and apples, can be detected effectively. However, it does not work well with bumpy products, such as peppers and paprika. The advantage of this method is that, unlike machine learning, it doesn't require large amounts of data. The proposed method could be applied to a screening system using X-rays and used not only in agricultural product screening systems but also in manufacturing processes such as processed food and parts manufacturing, so that it can be actively used to select defective products.

Analysis of the Electrical Defect Detection Mechanism using a Low Energy Electron Beam on the TFT Substrate for TFT-LCDs (TFT-LCD용 TFT기판에서 저에너지 전자빔을 이용한 전기적 결함 검출 메카니즘 분석)

  • Oh, Tae-Sik;Kim, Ho-Seob;Kim, Dae-Wook;Ahn, Seung-Joon;Lee, Gun-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.4
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    • pp.1803-1811
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    • 2011
  • We have analyzed the electrical defect detection mechanism using low energy microcolumn on the TFT substrate for TFT-LCD. In this study, we have acquired the SEM images of the various pixel defects for 7-inch TFT substrate by scanning of low energy electron beam in the high vacuum chamber. Futhermore, we have interpreted the defect detection mechanism through the correlations between the SEM images and electrical behaviors of the defective pixels. As a result, we obtained consistent results as the follows. We can confirm that the SEM images using low energy electron beam are significantly affected by the space charge effect.

Highlighting Defect Pixels for Tire Band Texture Defect Classification (타이어 밴드 직물의 불량유형 분류를 위한 불량 픽셀 하이라이팅)

  • Rakhmatov, Shohruh;Ko, Jaepil
    • Journal of Advanced Navigation Technology
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    • v.26 no.2
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    • pp.113-118
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    • 2022
  • Motivated by people highlighting important phrases while reading or taking notes we propose a neural network training method by highlighting defective pixel areas to classify effectively defect types of images with complex background textures. To verify our proposed method we apply it to the problem of classifying the defect types of tire band fabric images that are too difficult to classify. In addition we propose a backlight highlighting technique which is tailored to the tire band fabric images. Backlight highlighting images can be generated by using both the GradCAM and simple image processing. In our experiment we demonstrated that the proposed highlighting method outperforms the traditional method in the view points of both classification accuracy and training speed. It achieved up to 13.4% accuracy improvement compared to the conventional method. We also showed that the backlight highlighting technique tailored for highlighting tire band fabric images is superior to a contour highlighting technique in terms of accuracy.