• Title/Summary/Keyword: Vision loss

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Development of Precision Vision Inspection System for Micro Optical Parts using a New Optical Probe Implemented to have Multiple Fields of Views (다중광학창을 가진 광학소자 자동 검사 시스템 개발)

  • 이일환;이기수;박희재
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.105-109
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    • 2001
  • The micro optical parts such as ferrules are required to be manufactured within very small tolerances, as the slight deviation of the tolerance would give very large amount of loss in communication efficiency. For efficient optical communication, outer diameter, fiber diameter, fiber separation and eccentricity are significant parameters to be inspected., Thus we developed an automatic inspection system to evaluate shape parameters of the optical fiber connectors(ferrule) upto submicron accuracy using machine vision. new optical probe of multi fields of views has been developed and the image processing and data analysis algorithms have been complemented in real time basis. The developed system is successfully used in the practical ferrule manufacturing industry, and about 0.1$\mu\textrm{m}$ accuracy can be obtained with very fast inspection time.

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Application of Image Processing on the Laser Welded Defects Estimation (레이저 용접물 결함 평가에 대한 화상처리의 이용)

  • Lee, Jeong-Ick;Koh, Byung-Kab
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.4
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    • pp.22-28
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    • 2007
  • The welded defects are usually called user's unsatisfaction for appearance and functional usage. For checking these defects effectively without time loss, setup of weldability estimation system is an important for detecting whole specimen quality. In this study, after catching a rawdata on welded specimen profiles and treating vision processing with these data, the qualitative defects are estimated from getting these information by laser vision camera at first. At the same time, the weldability estimation for whole specimen is produced. For user friendly, the weldability estimation results are shown each profiles, final reports and visual graphics method. So, user can easily determined weldability. By applying these system to welding fabrication, these technologies are contribution to on-line setup of weldability estimation system.

Bilateral Visual Loss as a Sole Manifestation Complicating Carotid Cavernous Fistula

  • Yu, Jeong-Keun;Hwang, Gyo-Jun;Sheen, Seung-Hun;Cho, Yong-Jun
    • Journal of Korean Neurosurgical Society
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    • v.49 no.4
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    • pp.229-230
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    • 2011
  • Visual loss is one of the ocular symptoms resulting from a carotid cavernous fistula (CCF), but has rarely been reported as the sole manifestation in CCF. Visual impairment is known to be associated with a poor outcome unless timely intervention is employed. Herein, the authors report a patient with bilateral rapid progressing visual loss as a sole manifestation in CCF. Vision was successfully restored by transarterial embolization. The authors discuss the necessity of urgent fistula obliteration in patients with visual loss.

Deep learning-based de-fogging method using fog features to solve the domain shift problem (Domain Shift 문제를 해결하기 위해 안개 특징을 이용한 딥러닝 기반 안개 제거 방법)

  • Sim, Hwi Bo;Kang, Bong Soon
    • Journal of Korea Multimedia Society
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    • v.24 no.10
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    • pp.1319-1325
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    • 2021
  • It is important to remove fog for accurate object recognition and detection during preprocessing because images taken in foggy adverse weather suffer from poor quality of images due to scattering and absorption of light, resulting in poor performance of various vision-based applications. This paper proposes an end-to-end deep learning-based single image de-fogging method using U-Net architecture. The loss function used in the algorithm is a loss function based on Mahalanobis distance with fog features, which solves the problem of domain shifts, and demonstrates superior performance by comparing qualitative and quantitative numerical evaluations with conventional methods. We also design it to generate fog through the VGG19 loss function and use it as the next training dataset.

Siamese Neural Networks to Overcome the Insufficient Data Problems in Product Defect Detection (제품 결함 탐지에서 데이터 부족 문제를 극복하기 위한 샴 신경망의 활용)

  • Shin, Kang-hyeon;Jin, Kyo-hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.108-111
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    • 2022
  • Applying deep learning to machine vision systems for defect detection of products requires vast amounts of training data about various defect cases. However, since data imbalance occurs according to the type of defect in the actual manufacturing industry, it takes a lot of time to collect product images enough to generalize defect cases. In this paper, we apply a Siamese neural network that can be learned with even a small amount of data to product defect detection, and modify the image pairing method and contrastive loss function by properties the situation of product defect image data. We indirectly evaluated the embedding performance of Siamese neural networks using AUC-ROC, and it showed good performance when the images only paired among same products, not paired among defective products, and learned with exponential contrastive loss.

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Retrospective Study of Anterior Lens Luxation in 8 Dogs (개의 수정체 전방 탈구 8례에 대한 후향적 연구)

  • Kim, Se-Eun;Park, Shin-Ae;Kim, Won-Tae;Jeong, Man-Bok;Chae, Je-Min;Park, Young-Woo;Seo, Kang-Moon
    • Journal of Veterinary Clinics
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    • v.25 no.4
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    • pp.292-294
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    • 2008
  • The purpose of this study was to evaluate the cause of lens luxation and to determine the frequency of vision loss, glaucoma, cataract, and corneal edema before and after intracapsular lens extraction (ICLE). The medical records of 8 dogs underwent ICLE for the correction of anterior lens luxation at the Veterinary Medical Teaching Hospital of Seoul National University from August 2005 to September 2007 were reviewed. The most frequently affected breed was Miniature Poodle (n = 3). The mean age was $10.8{\pm}2.1$ years. Preoperatively, 5 eyes (67.5%) with anterior luxation had secondary glaucoma, 7 eyes (87.5%) had vision loss, and all eyes (100.0%) had corneal edema. Four weeks after ICLE, 6 eyes (75.0%) had normal intraocular pressure (IOP), and 4 eyes (50.0%) regained vision. Corneal edema was reduced after ICLE in all eyes, but still remained in 4 eyes. It was considered that ICLE was beneficial in the management of anterior lens luxation, but the eyes without glaucoma before ICLE had more favorable prognosis than eyes with.

Quality Assessment of Beef Using Computer Vision Technology

  • Rahman, Md. Faizur;Iqbal, Abdullah;Hashem, Md. Abul;Adedeji, Akinbode A.
    • Food Science of Animal Resources
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    • v.40 no.6
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    • pp.896-907
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    • 2020
  • Imaging technique or computer vision (CV) technology has received huge attention as a rapid and non-destructive technique throughout the world for measuring quality attributes of agricultural products including meat and meat products. This study was conducted to test the ability of CV technology to predict the quality attributes of beef. Images were captured from longissimus dorsi muscle in beef at 24 h post-mortem. Traits evaluated were color value (L*, a*, b*), pH, drip loss, cooking loss, dry matter, moisture, crude protein, fat, ash, thiobarbituric acid reactive substance (TBARS), peroxide value (POV), free fatty acid (FFA), total coliform count (TCC), total viable count (TVC) and total yeast-mould count (TYMC). Images were analyzed using the Matlab software (R2015a). Different reference values were determined by physicochemical, proximate, biochemical and microbiological test. All determination were done in triplicate and the mean value was reported. Data analysis was carried out using the programme Statgraphics Centurion XVI. Calibration and validation model were fitted using the software Unscrambler X version 9.7. A higher correlation found in a* (r=0.65) and moisture (r=0.56) with 'a*' value obtained from image analysis and the highest calibration and prediction accuracy was found in lightness (r2c=0.73, r2p=0.69) in beef. Results of this work show that CV technology may be a useful tool for predicting meat quality traits in the laboratory and meat processing industries.

A Study on Vinyl House Disease Among Farmers in Kyeongnam Province (경상남도 일부 지역의 비닐하우스병에 관한 조사연구)

  • Kim, Byung-Sung;Park, Tae-Jin
    • Journal of agricultural medicine and community health
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    • v.19 no.1
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    • pp.15-23
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    • 1994
  • In order to find out the frequencies of symptoms and the relations between the symptoms and working hours, the numbers of spraying pesticides authors investigated 145 farmers(96 male, 49 female persons) from 6 Myon's of 3 Gun's in Kyeongnam Province. The results were as follows; 1. The most frequent farming years were 1-5 years, fruits were the most common, and working hours were over 9 hours in 41.4%. The commonly used pesticides were insecticides, herbicides, herbicides in order. Only 52.4% of the farmers used masks, and 69.0% bathed after spraying pesticides. 2. The most common symptoms being complained were sweating, lumbago, shoulder pain, dizziness, headache, fatigue, decreased vision, weight loss, dyspnea and nausea in order. 3. Dizziness was more common in younger ages and decreased vision was more common in elder ages. Dyspnea and shoulder pain were more common in female farmers. 4. The more longer the working hours, the more complained indigestion, lumbago, shoulder pain and nausea. The more faster came into vinyl-house after spraying pesticides, the more common fatigue and dizziness. 5. The farmers who sprayed more pesticides complained headache, dyspnea, weight loss. 6. Vinyl house workers who worked more than 7 hours complained headache, nausea, decreased vision, lumbago more frequently than who worked less than 6 hours. 7. The farmers who entered in 1-2 hours after spraying pesticides complained fatigue more frequently than those entered after 3 hours. 8. Vinyl house workers without using masks complained dizziness and dyspnea more commonly than those using masks. But headache was more common among those using masks contrary to expectation.

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Attention Deep Neural Networks Learning based on Multiple Loss functions for Video Face Recognition (비디오 얼굴인식을 위한 다중 손실 함수 기반 어텐션 심층신경망 학습 제안)

  • Kim, Kyeong Tae;You, Wonsang;Choi, Jae Young
    • Journal of Korea Multimedia Society
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    • v.24 no.10
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    • pp.1380-1390
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    • 2021
  • The video face recognition (FR) is one of the most popular researches in the field of computer vision due to a variety of applications. In particular, research using the attention mechanism is being actively conducted. In video face recognition, attention represents where to focus on by using the input value of the whole or a specific region, or which frame to focus on when there are many frames. In this paper, we propose a novel attention based deep learning method. Main novelties of our method are (1) the use of combining two loss functions, namely weighted Softmax loss function and a Triplet loss function and (2) the feasibility of end-to-end learning which includes the feature embedding network and attention weight computation. The feature embedding network has a positive effect on the attention weight computation by using combined loss function and end-to-end learning. To demonstrate the effectiveness of our proposed method, extensive and comparative experiments have been carried out to evaluate our method on IJB-A dataset with their standard evaluation protocols. Our proposed method represented better or comparable recognition rate compared to other state-of-the-art video FR methods.

Comparison of Contrast Sensitivity Between Soft Contact Lens Wearers and Spectacle Wearers (콘택트렌즈와 안경 착용자의 대비감도 비교)

  • Kim, Jai-Min;Lee, Min-Ah
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.4
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    • pp.119-125
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    • 2007
  • The aim of the present study was to compare the contrast sensitivity of soft contact lens wearers, spectacle wearers or emmetropia. Seventy myopic eyes and thirty emmetropic eyes aged 19 to 26 years were collected. The myopic group included 48 eyes corrected with spectacle lenses and 22 eyes of them corrected with contact lenses, too: all had corrected vision acuity of 20/20 or better. Spatial contrast sensitivity was measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView  Functional Vision Analysis software at photopic or mesoopic condition. There was no significant difference in contrast sensitivity between spectacle lenses and emmetropes. Myopes corrected with soft contact lenses showed statistical sensitivity losses at 1.5, 12 cycle/degree spatial frequencies. In conclusion, our findings suggest that loss of contrast sensitivity in soft contact lens wearers might be interpreted as evidence for corneal disruption before corneal pathological events occur in contact lens wearers. Contrast sensitivity testing appears to be a useful method for evaluating soft contact lenses.

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