• Transactions of Materials Processing
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• v.12 no.5
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• pp.487-492
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• 2003

Tension variations with heat treatment in shadow mask for flat braun tubes are investigated in this study. In CRT, landing shift of the electron beam due to thermal deformation of the tension mask made the color purity of screen worse. In order to get the final results of thermal deformation, the tensile force within the mask and the welding processes between the rail and the extended mask have to be analysed sequentially. In this study, the effect of heat treatment is studied in terms of tension variations of shadow mask during its manufacturing process.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.61-69
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• 2014

With the extreme ultraviolet (EUV) lithography, the performance limit of chemically amplified resists has recently been extended to 16- and 11-nm nodes. However, the line edge roughness (LER) and the line width roughness (LWR) are not reduced automatically with this performance extension. In this paper, to investigate the impacts of the EUVL mask and the EUVL exposure process on LER, EUVL is modeled using multilayer-thin-film theory for the mask structure and the Monte Carlo (MC) method for the exposure process. Simulation results demonstrate how LERs of the mask transfer to the resist and the exposure process develops the resist LERs.

• Fashion & Textile Research Journal
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• v.25 no.1
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• pp.82-91
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• 2023

The children who are part of this study are compelled to wear masks at educational facilities for an extended period of time as they continue to be exposed to Asian dust, fine dust, and COVID-19. However, use of masks is currently causing them a lot of inconvenience. This study aimed to gather basic data for the development of a mask that is suitable and comfortable for children to wear. A total of 331 children aged 1 to 9 were investigated through their parents in terms of their lifestyle, mask wearing and purchasing status, mask preferences, mask inconvenience, and mask improvement. According to the survey on mask use, the proportion of children aged 1-3 years old and wearing ultra-small/XS masks, 4-6 year olds wearing small/S, and 7-9 year olds wearing small/S was the highest. More than 80% of children were wearing masks with a standard filter of KF80 or higher. The purchase criteria for children's masks were found to be excellent in terms of wearing comfort and meeting the filter standards. According to the survey on inconvenience of wearing masks, the majority of those surveyed expressed the need to develop children's masks of different sizes. Furthermore, they experienced various kinds of inconveniences from adult masks, such as the material quality and length of earring bands; it was deduced that these aspects need to be taken care of. The vertical folding type was the most popular in the mask design for children. Children have to wear masks for a prolonged period of time, but they are experiencing lot of inconvenience, which need to be addressed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.431-433
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• 2022

With the development of IoT technology, various technologies such as artificial intelligence and automation are being grafted into industrial sites, and accordingly, the importance of data processing is increasing. Image denoising is one of the basic processes of image processing, and is used as a preprocessing step in many applications. Various studies have been conducted to remove noise, but various problems arise in the process of noise removal, such as image detail preservation, texture restoration, and special noise removal. In this paper, we propose a digital filter using an extended convolutional mask to preserve image detail during the impulse denoising process. The proposed algorithm uses an extended convolution mask as a filtering mask, and obtains the final output by switching the extension level according to the noise level. Simulation was conducted to evaluate the performance of the proposed algorithm, and the performance was analyzed compared to the existing method.

• Archives of Craniofacial Surgery
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• v.24 no.2
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• pp.66-72
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• 2023

Background: During the coronavirus disease 2019 (COVID-19) pandemic, the everyday use of face masks massively increased to prevent the spread of infection. Many people complain of ear pain and erosion when wearing a mask for extended periods of time. If prolonged mask usage is uncomfortable for ordinary people, a question arises-how much more inconvenient must mask wearing be for patients with a full-thickness skin graft (FTSG) donor site in the retroauricular region? Herein, we evaluated complications related to face mask use in 27 patients with a retroauricular FTSG donor site, with the goal of clarifying whether the retroauricular region is still an appropriate FTSG donor site in the context of the COVID-19 pandemic. Methods: Complications in 27 patients treated by FTSGs harvested from the retroauricular region from 2019 to 2021 were investigated. A questionnaire comparing the normal and the operated sides was administered. Pain, itching, soreness, deformity, and symmetry were further investigated. Results: Pain and itching were the only observed complications. The operated side was slightly more painful than the normal side in four patients (14.8%), and four patients (14.8%) reported itching on the operated side. However, all patients who experienced complications stated that the pain or itching did not interfere with mask wearing. Most symptomatic patients were older than 60 years of age (23.8%, p= 0.185) and wore masks for longer periods of time (28.5%, p= 0.326). Conclusion: Few retroauricular donor site-related complications occurred, and none of these complications caused inconvenience in daily life. Therefore, in the COVID-19 pandemic, the use of the retroauricular region as an FTSG donor site remains appropriate.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.146-153
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• 2018

This paper presents a superresolution demosaicing technique that can restore high-resolution color image from differently blurred low resolution images in Bayer domain. The proposed superresolution demosaicing algorithm uses an aperture mask wheel to get differently blurred low resolution images, so we just need to estimate point spread function at each frame. In addition, it does not require image registration because there is no translational motion between low resolution images. By using a rotatable aperture mask wheel, consecutive captured images provide sufficiently exclusive information for superresolution. Therefore, the proposed method can reduce the registration error between the low-resolution image as well as the calculation amount for superresolution restoration. The existing lens system of the camera can be extended to obtain a superresolution image by only adding an rotatable aperture mask wheels. Finally, in order to verify the performance of the proposed system, experimental results are performed. The proposed method showed the significant improvements in the sense of spatial and color resolution.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.130-136
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• 2015

In this paper, we analyzed the adjacent channel interference of the LTE band 40 defined by 3GPP on the WLAN system based on the Monte-Carlo method, and found the guard band required for compatibility between the two systems. This study have a difference compared to the previous studies about cell radius was determined using Extended Hata Model considering practical environment, interference protection distance related to guard band, and the spectrum emission mask improvement effect for minimizing the interference. Simulation results, for no channel interference compatibility of LTE and WLAN for mobile satellite wireless package system, we can find the need 15MHz guard band at specified spectrum emission mask and 10MHz guard band at assumed spectrum emission mask.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.487-493
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• 2015

A wavefront coding (WFC) technique provides an extension of the depth of field for a microscopy imaging system with slight loss of image spatial resolution. Through the analysis of the relationship between the incidence angle of light at the phase mask and the system pupil function, a mixing symmetrical cubic phase mask (CPM) applied to 5X-40X micro-objectives is optimized simultaneously based on point-spread function (PSF) invariance and nonzero mean values of the modulation transfer function (MTF) near the spatial cut-off frequency. Optimization results of the CPM show that the depth of field of these micro-objectives is extended 3-10 times respectively while keeping their resolution. Further imaging simulations also prove its ability in enhancing the defocus imaging.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.461-463
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• 2000

This paper presents a low temperature excimer-laser-crystallization that produces directionally solidified microstructure in Si thin films. The process involves (1) a complete melting of selected area via irradiation through a patterned mask. and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the superlateral growth(SLG) distance. (3) lateral growth extended over a number of iterative steps. Grains that grow continuously to the vertical direction were demonstrated. We discuss sequential lateral solidification principle, experiment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.253-255
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• 2022

Thanks to the 4th industrial revolution and the development of various communication media, technologies such as artificial intelligence and automation are being grafted into industrial sites in various fields, and accordingly, the importance of data processing is increasing. Image noise removal is a pre-processing process for image processing, and is mainly used in fields requiring high-level image processing technology. Various studies have been conducted to remove noise, but various problems arise in the process of noise removal, such as image detail preservation, texture restoration, and noise removal in a special area. In this paper, we propose a switching mask filter based on the noise intensity to preserve the detailed image information during the impulse noise removal process. The proposed filter algorithm obtains the final output by switching to the extended mask when it is determined that the density is higher than the reference value when noise is determined in the area designated as the filtering mask. Simulation was conducted to evaluate the performance of the proposed algorithm, and the performance was analyzed compared to the existing method.