• 대한기계학회논문집B
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• 제36권10호
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• pp.1011-1017
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• 2012

본 논문에서는 롤타입 마스크를 사용한 마이크로/나노 구조 제작용 광학 리소그래피 방법을 소개한다. 이 생산 방법은 다양한 목표 해상도에 따라 위상지연 리소그래피방법과 포토리소그래피로 나뉜다. 사용되는 빛의 파장대보다 작은 해상도를 갖는 패턴을 제작하기 위해서 실린더 형태의 위상지연 마스크를 활용한 근거리 노광 방식을 사용한다. 또한 필름 형태의 금속 마스크를 써서 포토리소그래피를 연속방식으로 수행하였는데 이 방식은 실린더 마스크의 회전수를 조절함으로써 노광 결과 패턴의 주기를 실시간으로 조절할 수 있다. 이 기술의 응용으로 금속 그물패턴으로 만들어진 100 $mm^2$ 넓이의 투명전극을 제작하였다.

• 한국산업보건학회지
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• 제10권2호
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• pp.98-108
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• 2000

Controlling the over-exposure of welding fumes is not an easy problem because neither general nor local exhaust ventilation systems could be successfully applied. A jet air supplying welding mask was development to reduce the exposure level of welding fumes. The jet airs tream pushes the welding fumes away from the breathing zone by using the frictional characteristic of jet. Laboratory experiments were conducted to optimize the efficiency of controlling welding fumes. Thereafter, its performance was tested in a laboratory and an industrial field. The efficiencies of reducing the welding fume exposure were about 90% and 80% in a laboratory and an industrial field, respectively. Additionally, it resulted in elimination of heat inside the mask and enhancement of clear visuality.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1346-1350
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• 2018

An electrode-evaporation technology on both the top and bottom sides of the bare vertical-type single chip separated from the traditional substrate by cooling, was developed for III-nitride vertical-type single chip LEDs with thick GaN epilayer. The post-process of the cooling step was followed by sorting the bare vertical-type single chip LEDs into the holes in a pocket-type shadow mask for deposition of the electrodes at the top and bottom sides of bare vertical-type single chip LEDs without the traditional substrate for electrode evaporation technology for vertical-type single chip LEDs. The variation in size of the hole between the designed shadow mask and the deposited electrodes owing to the use of the designed pocket-type shadow mask is investigated. Furthermore, the electrical and the optical properties of bare vertical-type single chip LEDs deposited with two different shapes of n-type electrodes using the pocket-type shadow mask are investigated to explore the possibility of the e-beam evaporation method.

• Journal of the Korean Wood Science and Technology
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• 제50권6호
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• pp.490-498
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• 2022

The current study aimed to verify the image segmentation ability of rays in tangential thin sections of conifers using artificial intelligence technology. The applied model was Mask region-based convolutional neural network (Mask R-CNN) and softwoods (viz. Picea jezoensis, Larix gmelinii, Abies nephrolepis, Abies koreana, Ginkgo biloba, Taxus cuspidata, Cryptomeria japonica, Cedrus deodara, Pinus koraiensis) were selected for the study. To take digital pictures, thin sections of thickness 10-15 ㎛ were cut using a microtome, and then stained using a 1:1 mixture of 0.5% astra blue and 1% safranin. In the digital images, rays were selected as detection objects, and Computer Vision Annotation Tool was used to annotate the rays in the training images taken from the tangential sections of the woods. The performance of the Mask R-CNN applied to select rays was as high as 0.837 mean average precision and saving the time more than half of that required for Ground Truth. During the image analysis process, however, division of the rays into two or more rays occurred. This caused some errors in the measurement of the ray height. To improve the image processing algorithms, further work on combining the fragments of a ray into one ray segment, and increasing the precision of the boundary between rays and the neighboring tissues is required.

• 한국입자에어로졸학회지
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• 제19권1호
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• pp.1-11
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• 2023

Respiratory face masks are protective facepieces that are designed to filter inhaled air. They are easy-to-use devices that can protect the wearer against various hazardous particles in the air. Respiratory face masks also prevent the spread of viruses and bacteria-containing droplets that are released from the coughing or sneezing of the infected people. During the COVID-19 pandemic, various types of face masks have circulated on the market. Their ability to filter sub-micron particles, which are the sizes of harmful particulate matter and airborne viruses, needs to be investigated. Their breathability, the easiness of breath through the mask, also needs to be considered. In this study, wwe evaluated the performance of filters used for different types of face masks certified by different standards including Korean (KF94, KF80, KF-AD), USA (N95), and Chinese (KN95) standards. We also tested the filters of nanofiber masks and surgical masks for which there are no standards for filtration test. The N95 mask filters showed the highest quality factor for capturing virus-sized particles. The other types of mask filters have acceptable performance except for nanofiber mask filters whose performance is very low.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2020년도 제62차 하계학술대회논문집 28권2호
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• pp.625-628
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• 2020

현재 지구촌은 신종 감염병인 '코로나바이러스 감염증-19(COVID-19)로 인해 혼란을 겪고 있다. 우리나라의 경우 1만 명 이상 감염자가 발생하였으며, 사망자 역시 200여 명이 넘었다. 하지만 위와 같은 감염병을 치료하기 위한 백신은 계속 개발중에 있으며, 현재는 감염 예방 수칙으로 감염의 위험성에서 벗어나고 있는 실정이다. 또, 지구촌에 큰 혼란을 주었던 사스, 신종플루, 메르스와 같이 주로 호흡기를 통해 타인에게 전파되는 신종 감염병 출현 빈도 역시 계속 증가하고 있다. 이외에는 황사, 미세먼지에 관한 문제들로 인해 일상속에서 이뤄지는 생활 방역의 중요성이 대두되고 있는 상황이다. 본 논문에서는 생활 방역의 대표적 수칙인 마스크 착용에서 상황별 올바른 마스크 선택의 중요성을 알려주어 시민의식을 높일 수 있는 VR 연동 'Wearing a Mask' 구현에 대해 제안하고자 한다.

• 한국의류학회지
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• 제48권3호
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• pp.417-432
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• 2024

This study aimed to enhance the comfort of health masks by conducting in-depth interviews, online surveys, and wearing tests on commercial health masks. The findings are summarized below. In-depth interviews revealed that the most comfortable mask styles were ranked as follows: Beak-1 (B-1) & Beak-2 (B-2) style > Flat style > 3-Horizontal foldable (3H) style. Men generally preferred flat style masks, while women favored beak-shaped masks. The internet survey results showed that 77.8% of surveyed brands offered a variety of mask styles, with 3H and B-2 masks being the most common. Different brands provided masks with different filtration levels, ranging from KF-AD to KF94. Size consistency also varied among brands, with flat masks having relatively consistent dimensions and B-2 masks showing significant size differences. Wearing tests indicated that 3H and B-1 masks were highly satisfying for categories like "itchiness," "unpleasant odor," and "mask slipping." Conversely, flat masks scored the highest satisfaction in classifications such as "stiff," "heavy," "thick," "hot while wearing it," "moisture accumulation," "breathing discomfort," "short ear straps," and "itchiness". Overall, the flat style, B-1, and B-2 yielded higher satisfaction levels, while 4-Horizontal foldable (4H) and 3H garnered lower satisfaction scores on wearing tests.

• 한국통신학회논문지
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• 제12권1호
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• pp.9-18
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• 1987

DPCM의 선형예측기를 비감광성 원소(dummy pixel)를 가지고 있는 선형 감광성 전하결합소자(CCD)를 광전자 시스템으로 구현하는 방법을 제시하였다. 종래의 시스템과 마찬가지로 이 시스템은 입력광원, 공간여파기(마스크), 선형감광성 CCD의 3부분으로 구성되었다. 비감광성 원소에 의한 시간지연을 고려하여 종래의 마스크를 변형하여 각 예측계수를 하나 이상의 마스크 원소에 분산시킨, 새로운 방식의 분산형 마스크를 제시하고 이 마스크를 사용할 때의 특성을 이론적으로 분석하였으며 실험으로 확인하였다.

• 한국산업융합학회 논문집
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• 제20권4호
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• pp.339-343
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• 2017

Masks are a portable functional product for daily use. They can protect user health by filtering harmful fine particles in the air. In the past decade, there have been approximately 10 yellow dust incidences per year, amounting to a total duration of 20 days, and they continue to increase year after year. In addition, the frequency of yellow dust incidences in Korea has increased by more than four times compared to levels from the 1970s. Statistical reports indicate that annual damages caused by yellow dust amount to more than six trillion KRW. This study developed a zero-fog multi-layer mask with a collection efficiency and yellow dust and particulate matter filtration areas that are at least thrice as effective as existing masks. The new mask also reduces pressure drag by half.

• 한국세라믹학회지
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• 제39권12호
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• pp.1124-1127
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• 2002

In this paper, we studied the effects of the electron reflection on shadow mask on which the electron reflecting materials with $WO_3-ZnS:Cu.Al-PbO-SiO_2$ system were screen-printed and we evaluated the variation of the electron beam mislanding in CRT. As a result, the green emitted spectra on the electron reflecting layer are observed due to the transformation of the electron energy, when the electron impacted on shadow mask. The beam mislanding is reduced about 40% in comperision with that of CRT made by the conventional method.