• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.671-673
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• 2016

In image data, noise occurs due to various external factors in the process of obtaining and transmitting. There are various types of noise according to the cause and form and research to remove this noise is being continued. Therefore the study suggested a way to filter to restore images damaged by salt and pepper noise which preserves non-noise signal and processes noise signal by expanding mask size according to the local mask noise density. In addition, as an objective evaluation standard of improvements, the study used PSNR(peak signal to noise ratio) to compare with previous methods.

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.214-217
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• 2020

2020년 1월 국내에 신종 코로나 바이러스의 확산으로 인해 보건 마스크의 수요가 급증하고 이에 따라 마스크의 가격이 폭등하자 정부가 건강보험정보를 기반으로 보건용 마스크 판매에 관여하는 공적 마스크 5부제를 시행해 왔다. 하지만 건강보험 가입정보에 의존적인 신원 인증 시스템으로 인해 유학생 등 건강보험 미가입자의 경우 마스크의 구입이 어렵고 개인정보 접근 문제 등으로 판매채널의 확장이 어려운 문제가 있었다. 본 논문에서는 건강보험과 같은 특정 신원정보 시스템에 의존하지 않고 중앙기관이 발행하는 신뢰할 수 있는 모든 신원정보(여권, 외국인등록증 등)에 기반하여 사용자가 스스로 자신의 신원정보 속성을 블록체인을 통해 관리하는 방법을 제안한다. 또한 제안 방법에 대해 디지털신원 기법을 평가할 수 있는 지표를 기반으로 자체 평가를 수행한다.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.571-577
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• 2018

Bicycle riders complain of many inconveniences when wearing glasses, sunglasses and masks. The disposable fine dust mask has been developed to resolve such inconveniences of bicycle riders. The scope of research is limited to the fiber which generates one-time static electricity and the shape of the mask due to the characteristic of fine dust mask. The purpose is to design and make the fine dust mask with a simple production process. The new disposable fine dust mask has secured enough space of the mask in front of the mouth by longitudinal folding and minimized stuffiness by maintaining the shape of the folded part to prevent touching the mouth even by heavy breathing. The streamlined sponge is attached at the part of nose support and the area of the cheek has been expanded to be about 2.5cm wider than ordinary masks to improve tight seal at the side. In addition, a new disposable fine dust scarf mask has been developed to block ultraviolet rays for the face and neck while filtering fine dust with the tight fine dust mask.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.311-313
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• 2020

컴퓨터 생성 홀로그램(CGH)에서 시야각은 매우 중요한 특성이다. 시야각에 따라 홀로그램을 볼 수 있는 영역이 결정되며 시야각을 넘어가게 되면 재구성된 오브젝트가 잘려 보이게 된다. CGH의 최대 시야각은 회절 격자 방정식에 의해 결정이 되며, 해당 수식에 따르면 홀로그램 재생 장치인 공간 광 변조기(SLM)의 픽셀 피치에 반비례한다. SLM의 픽셀 피치를 줄이는 것은 어렵고 비용이 많이 들기 때문에 본 논문에서는 고해상도 랜덤 바이너리 위상 마스크를 SLM에 부착하여 CGH의 시야각을 확장하는 방법을 제안한다. CGH를 계산하는데 자주 사용되는 반복 푸리에 변환 알고리즘(IFTA)에 위상 평균화 단계를 도입하여 SLM과 위상 마스크간의 픽셀 크기 및 개수의 차이를 극복하였다. 또한 스칼라 회절 이론을 바탕으로 한 홀로그램 시뮬레이션에 제안한 방법을 적용 후 가상 눈 모델을 도입하여 두 개의 물체로 이루어진 홀로그램을 재구성하고 여러 각도에서 관찰하여 시야각이 향상되는것을 검증하였다.

• The korean journal of orthodontics
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• v.40 no.6
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• pp.432-443
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• 2010

Objective: The purpose of this prospective study was to evaluate the dentofacial effects of conventional and modified facemask therapies with rapid maxillary expansion, in a group of Class III patients; and compared with an untreated control group. Methods: The conventional facemask group (Group 1) comprised of 24 patients, 13 girls and 11 boys (mean age, $9.2{\pm}1.4$ years); the modified facemask treatment group (Group 2) comprised of 24 patients, 12 girls and 12 boys (mean age, $9.3{\pm}1.6$ years); and the control group (Group 3) comprised of 21 subjects, 11 girls and 10 boys (mean age, $9.8{\pm}1.9$ years). Treatment and control changes within the groups and the differences between the groups were analyzed statistically. Intra-group comparisons were evaluated using the non-parametric Wilcoxon's test and intergroup changes were analyzed using the Kruskal-Wallis test. The statistical significance of intergroup differences was further assessed with the Mann-Whitney test for independent samples and applying Bonferroni's correction (p < 0.016). Results: In group 1, SNB changes were less than the control. There were increases in SNA, ANB, SN-MP, A to N perp and Upper lip to E plane. In group 2, SNB, U1-NA (mm) U1-NA (${\circ}$) and Pog to N perp (mm) changes were less than the control. There were increases in SNA, ANB, SN-MP, A to N perp and Upper lip to E plane. Conclusions: Modified facemask appliance can be used effectively in Class III patients with a retrognathic maxilla. Facemask therapies with expansion resulted in an anterior advancement and translation of maxilla without rotation; and the mandible moved downward and backward ward in both treatment groups.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.187-192
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• 2009

In this paper the extended algorithm of valley energy was proposed In order to detect the robust features of the face The proposed energy had the variable type without the constant size of valley mask for measuring the gray value among pixels By accumulating the results generated by the various masks the information of valley energy was so diversified. Then the robust energy which is independent of the environments was maded. The various experiments proved that The proposed method showed the detection rate of 98 percentage in the features of the face region.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.429-431
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• 2019

Noise in image processing has a direct effect on the quality of the image, and adversely affects the processing of the system including algorithms such as image segmentation, edge detection, and image recognition. Therefore, noise reduction plays an important role in the preprocessing process. In this paper, we propose an efficient algorithm to remove noise in high density of Salt and Pepper noise. The proposed algorithm removes noise by gradually expanding the filtering mask according to the density of the noise, and shows excellent noise cancellation performance even in a high density region. In order to evaluate the performance of the proposed algorithm, we compared and analyzed the existing method and the proposed algorithm through simulation.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.271-286
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• 2023

The global COVID-19 pandemic has transformed face masks from situational accessories to indispensable items in daily life, prompting a shift in public perception and behavior. While the relaxation of mandatory mask-wearing regulations is underway, a significant number of individuals continue to embrace face masks, turning them into a form of personal expression and identity. This phenomenon has given rise to the Fashion Mask industry, characterized by unique designs and colors, experiencing rapid growth in the market. However, existing research on masks is predominantly focused on their efficacy in preventing infection or exploring attitudes during the pandemic, leaving a gap in understanding consumer preferences for mask design. We address this gap by investigating consumer perceptions and preferences for two prevalent mask designs-horizontal fold flat masks and vertical fold flat masks. Through a comprehensive approach involving surveys and eye-tracking experiments, we aim to unravel the subtle differences in how consumers perceive these designs. Our research questions focus on determining which design is more appealing and exploring the reasons behind any observed differences. The study's findings reveal a clear preference for vertical fold flat masks, which are not only preferred but also perceived as unique, sophisticated, three-dimensional, and lively. The eye-tracking analysis provides insights into the visual attention patterns associated with mask designs, highlighting the pivotal role of the fold line in influencing these patterns. This research contributes to the evolving understanding of masks as a fashion statement and provides valuable insights for manufacturers and marketers in the Fashion Mask industry. The results have implications beyond the pandemic, emphasizing the importance of design elements in sustaining consumer interest in face masks.

• 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.