• 치위생과학회지
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• 제21권1호
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• pp.1-7
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• 2021

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted primarily through droplets, and dental practitioners are at risk of occupational exposure to SARS-CoV-2 infection owing to direct contact with the patient's mouth, aerosols from dental procedures, and saliva. Wearing a mask is believed to be the best method of protection against infection, and a systematic literature review was conducted on whether the dental masks used in dentistry are effective in preventing Coronavirus Infectious Disease-19 (COVID-19). Methods: We used PubMed, Google Scholar, DBpia, NDSL, and KISS databases for this study. Of the 917 documents narrowed down by the search terms "Coronavirus, COVID-19, and dental," 83 documents were collected and studied. Ultimately, 42 of these papers were selected for analysis after considering duplication from the flow chart of the literature selection process. Results: While dental masks are often used when treating patients with unknown COVID-19 status, the Ministry of Food and Drug Safety stated that the use of dental masks is insufficient in preventing cross-transmission of COVID-19; instead, it was recommended that N95 masks, which correspond to KF94 masks, should be worn daily. On the other hand, wearing a dental mask and following precautions such as hand hygiene may not pose a significantly higher risk of infection than wearing an N95 mask when treating COVID-19 patients. Conclusion: There is an ongoing discussion regarding the use of dental masks when treating dental patients, and many argue that different types of masks should be selected according to the degree of infection and the individual's respiratory condition. By considering the safety and efficacy of dental masks in preventing infection, improvements can be made in the management of COVID-19 and dental-related infections.

• 복식문화연구
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• 제30권3호
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• pp.455-476
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• 2022

The aim of this study was to develop Jiangxi Nuo masks using 3D digital fashion design technology and suggest various ways to utilize traditional culture based on the characteristics of Nuo masks, a traditional Chinese artifact of intangible cultural significance. The researchers conducted a literature review to gather information about Nuo culture and masks that could represent Jiangxi. Features of the masks were analyzed and classified. The result are as follows. First, the symbolic characteristics of Jiangxi's Nuo masks can be divided into those based on their origin and history, the user's social status, and the notions of primitive beliefs of the chosen people, such as naturism and totemism. Second, Nuo masks' splendid decorations convey meanings such as luck, the bixie, longevity, wealth, and peace in the family. Third, playfulness in mask-making is about dismantling the original form of the mask, re-creating it through application. Fourth, the masks express primitiveness mostly by conserving the wood's original color or material. The initial masks carved to represent images of figures aptly deliver the primitive forms and images of Nuo culture. In this study, Nuo masks were developed and produced using the 3D digital technology CLO 3D by adopting the expressive characteristics and applying design methods such as asymmetricity, exaggeration, and modification. The results of this study demonstrate the possibility of creating diverse as well as economical designs through the reduction of production.

• 한국의류학회지
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• 제46권2호
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• pp.292-309
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• 2022

The ongoing COVID-19 pandemic has caused a recession in the fashion industry. Therefore, this study aims to assess the influence of face masks on the selection of fashion products by Korean women in their twenties and thirties. This is highly relevant as the mandatory donning of face masks becomes a social norm. To this end, an in-depth interview and a survey were conducted. The results indicate that wearing a face mask affects consumers' fashion selection criteria in regard to styles, materials, colors, and types. Face masks have gradually contributed to the unification and simplification of fashion styles due to the atmosphere and wearing of the mask itself, which has led to a decline in the overall interest in fashion. Most consumers in this study felt a disconnect between face masks and fashion products, since the former have not been established within most fashion styles. Consequently, consumers had difficulty naturally aligning face masks with various fashion styles, which eventually led to a decreased interest in fashion. This study is significant in that it provides objective data that can be utilized to establish strategies in the fashion industry regarding the integration of face masks.

• 한국의류학회지
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• 제46권1호
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• pp.116-131
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• 2022

This study used text mining to analyze big data to understand consumers' demand for and perceptions of fashion masks. Based on the text-mining analysis results, a survey was conducted with those living in Korea to investigate the influence of consumers' mask selection criteria on mask brand awareness and purchase intention for fashion masks. "Fashion mask" and "functional mask" were used as the keywords in a text-mining analysis, and an online survey of 242 respondents was conducted. The analysis results were as follows: First, the text-mining analysis extracted commonly appearing words that had a high frequency and TF-IDF, such as "COVID-19," "fashion," "celebrity," "antibacterial," and "filter." This confirmed that during the COVID-19 pandemic, consumers have demanded masks that are both functional and fashionable. Second, among consumers' mask selection criteria, trend and design had positive effects on face-mask brand awareness. Third, face-mask brand awareness had a positive effect on the purchase intention for both brand and fashion masks, and the purchase intention for brand masks had a positive effect on the purchase intention for fashion masks.

• 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.

• 한국환경보건학회지
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• 제41권3호
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• pp.203-215
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• 2015

Objectives: This study was designed to evaluate the filtration efficiencies and pressure drops of five commercial cloth masks (4 plate type, 1 cup type) in comparison to the performance of a class 1 disposable respirator (reference respirator). A further objective was to evaluate the effects of the number of layers and wash treatment independently on filtration efficiencies and pressure drops. Methods: Polydisperse NaCl aerosols were generated in an aerosol chamber and their concentrations were measured by an optical particle counter (OPC) in the size range of $0.3{\sim}10{\mu}m$ (five channels). Results: The filtration efficiencies of the five cloth masks and the reference respirator were D: 9.5%, C: 18.5%, E: 23.6%, A: 28.5%, B: 29.7% and R: 91.1%, respectively, and the pressure drops through them were C, D: 0.8 Pa, E: 1.7 Pa, B: 6.4 Pa, A: 42.7 Pa and R: 19.3 Pa, respectively. The filtration efficiencies of the cloth masks and reference respirator were below the class 1 respirator criterion (${\geq}94.0%$) of the Ministry of Employment and Labor (MOEL) and Ministry of Food and Drug Safety (MFDS). The pressure drops satisfied the class 1 respirator criterion (${\leq}70Pa$) of MOEL and MFDS. When the cloth masks were folded into two and four layers, the filtration efficiencies of cloth masks A, B, C, D (plate type) increased 1.7-4.6 times, and 2.3-6.8 times, respectively, compared to the efficiencies of the same products in a single layer. Pressure drops increased as the number of layers was increased. The filtration efficiency of cloth mask E with a liner was 1.3 times higher than that of the same mask without a liner, and the pressure drop was lower in the no-liner configuration. After a single washing, the filtration efficiencies of all the cloth mask products decreased 1.04-4.0 times compared to those of the same products intact. For the cloth masks C and E, their filtration efficiencies were significantly decreased after washing (p<0.05). The pressure drops of all cloth masks were 1.2-2.0 times lower after washing. Conclusions: The filtration efficiencies of the five cloth masks were below 30% and did not improve greatly by increasing the number of layers. After a single washing, their performances decreased. Considering the above and other issues identified with cloth masks, such as poor fit and stretched fibers through use, people should not expect protection against particulate matters from the cloth masks on the market.

• 한국환경보건학회지
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• 제48권2호
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• pp.116-122
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• 2022

Background: The recent COVID-19 pandemic is one of the worst disease outbreaks of the 21th century. Due to a lack of reliable antiviral therapeutics, wearing face masks is recommended to prevent airborne infection originating from virus-contaminated bioaerosols. Objectives: The aim of this study was to evaluate the filtration efficiencies of face masks that are commercially available in South Korea for a biological aerosol of Staphylococcus aureus (S. aureus) and murine coronavirus, a well-known surrogate for human coronaviruses. Methods: We collected six different kinds of commercial masks: two Korea Filter (KF)94 (KF94-1, KF94-2) masks, one surgical (Surgical-1) mask, one anti-droplet (KF-AD-1) mask, and two dust (Dust-1, Dust-2) face masks. S. aureus (ATCC 6538), a well-performing test bacteria and murine coronavirus (ATCC VR-764) were prepared under a suitable culture condition. Then, a mask biological filtration tester was used to examine the microbial filtration efficiencies of masks. Test microorganisms were quantitatively measured via cultivation methods and microbial filtration efficiencies were calculated appropriately. Results: All face masks showed over 99.6% filtration efficiency for S. aureus or murine coronavirus. There were no significant differences among the bacterial filtration efficiencies of the face masks. KF94-1 (99.97±0.08%) and Dust-1 mask (99.97±0.07%) showed the highest (over 99.9%) filtration efficiency for murine coronavirus. KF94-1 or Dust-1 masks showed a significant virus filtration efficiency compared to Surgical-1 mask (p<0.05; Mann-Whitney U test). Conclusions: All the commercially available face masks used in this study can filter S. aureus or murine coronavirus in bioaerosols efficiently, regardless of the mask type. Therefore, our results suggest that wearing a certified face mask is a reliable means to prevent the transmission of infectious airborne diseases via biological aerosols.

• 한국산업보건학회지
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• 제31권1호
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• pp.94-104
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• 2021

Objectives: A number of medical institutions have been conducting fit tests to perform seal checks on masks. This study aimed to compare the differences fit factor before and after domestic N95 mask-wearing training through a fit-test. Methods: A survey of 59 healthcare workers was conducted regarding whether they had undergone a fit test or received training on mask-wearing. Further, the fit of two types of domestic N95 masks was measured before and after the training using a QNFT(Quantitative Fit test). The average fit factors before and after training were compared using a paired t-test. Additionally the differences in the fit test pass rate were analyzed using a McNemar test. Results: A statistically significant difference was seen between the fit factors in the fit tests conducted before and after the training (p=0.0015), as well as in the fit of the two types of masks tested (p<0.01). Thus, an improvement in mask fitting was seen after the training, even with differently fitted masks. Conclusions: Upon using a QNFT, a significant increase in the fit factors for N95 masks was observed after training compared with masks that were fitted as usual. This highlights the importance of training in mask-wearing, with the conclusion that training healthcare providers will improve the fit of masks.

• 한국의상디자인학회지
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• 제25권3호
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• pp.113-125
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• 2023

The COVID-19 pandemic has led to the normalization of mask-wearing worldwide, and young children are particularly vulnerable to respiratory diseases. Children's masks come in various sizes and shapes, causing confusion among consumers who struggle to find products that can accommodate their child's unique physical conditions. This research aims to analyze the shape and dimensions of health masks designed for young children. A total of 67 mask varieties were collected, and 58 were subjected to analysis. The masks were found to have two primary shapes: foldable and beak-like, with sizes categorized as small and extra-small. The majority of masks were manufactured in Korea, and the size labeling systems varied among manufacturers. The mask materials were non-woven fabric or polypropylene, and there was diversity in terms of the adjustable earbands and the use of additional accessories. The dimensions of the masks varied depending on their shape, with significant differences in the weight and the length of the wire holes. Subsequent research should focus on conducting wearability evaluations to verify the dimensional suitability of commercially available children's health masks based on shape and size. Additionally, this study aims to provide foundational data that can assist in the development of children's masks with size ranges that differentiate them from adult masks and cater to specific age groups.

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.266-276
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• 2010

In the present study, an optical system is proposed for maskless lithography using a digital micromirror device (DMD). The system consists of an illumination optical system, a DMD, and a projection lens system. The illumination optical system, developed for 95% uniformity, is composed of fly's eye lens plates, a 405 nm narrow band pass filter (NBPF), condensing lenses, a field lens and a 250W halogen lamp. The projection lens system, composed of 8 optical elements, is developed for 4 ${\mu}m$ resolution. The proposed system plays a role of an optical engine for PCB and/or FPD maskless lithography. Furthermore, many problems arising from the presence of masks in a conventional lithography system, such as expense and time in fabricating the masks, contamination by masks, disposal of masks, and the alignment of masks, may be solved by the proposed system. The proposed system is verified by lithography experiments which produce a line pattern with the resolution of 4 ${\mu}m$ line width.