• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.292-301
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• 2021

Objectives: Wearing medical masks has been recommended since the declaration of coronavirus disease-19 (COVID-19) as a pandemic disease. Certified medical masks are evaluated according to filtration efficiency and facial inhalation resistance. However, some people use non-certified common masks. This study aimed to evaluate various non-certified commercial masks based on the certification criteria for medical masks. Methods: Twenty mask products (three anti-droplet, three disposable dental, eight fashion, three cotton, and three children's masks) were selected. For performance evaluation, filtration efficiency and facial inhalation resistance tests were conducted. The evaluation method followed the certification method for KF-certified masks of the Ministry of Food and Drug Safety (MFDS) and the N95 respirator of the National Institute for Occupational Safety and Health (NIOSH). Results: None of the 20 masks met the KF94 certification standard set by the MFDS. Four and three masks respectively met the KF80 certification standard and the N95 standard of NIOSH. Filtration efficiency was significantly higher in three-layer masks than in single layer masks. Pleated-type masks had higher filtration efficiency than cone-type masks. There was no correlation between the structure of masks and facial inhalation resistance. Conclusion: While no masks complied with the KF94 certification standard, a few masks met the KF80 and the N95 certification standards of NIOSH. Although some people wear non-certified commercial masks, protection from aerosols is not guaranteed by such masks. Evaluation of the protection efficiency of non-certified mask against microbiological infection is needed for the prevention of infectious disease.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.3
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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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.2
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• pp.115-122
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• 2017

Objectives: This study was designed to evaluate the changes in the particle filtration efficiencies of five cloth masks (4 plate types, 1 cup type) with an increasing number of machine washings and the degree of cloth expansion. Methods: NaCl aerosols were generated using an atomizer and passed through cloth masks in a dynamic aerosol chamber. Particle concentrations were measured both before and after for the cloth masks using an optical particle counter (OPC) in the size range of $0.3{\sim}10{\mu}m$. Results: In the original condition, the filtration efficiencies of the five cloth masks were A: 20.1%, B:30.9%, C: 25.0%, D: 26.5%, and E: 40.9%. As the number of washings increased in the order of one, two, and four times, the filtration efficiencies of cloth mask C increased. The filtration efficiency of A, D, and E increased after the first washing. With the exception of B, the filtration efficiency of cloth masks increased after the second washing and those of all cloth masks increased after the fourth washing. This might be caused by the fibers untangling from the yarn and being freed at one end. In this status, the packing density of the textile will not change, but the distances between fibers will increase, which might bring about an increase in filtration efficiency. When the cloth masks were extended by 10% and 20% in one direction, the filtration efficiencies of cloth masks B, D, and E decreased at 10% extension, and those of all cloth masks decreased at 20% extension. When the cloth masks were expanded by 10% and 20% in two directions, the filtration efficiencies of all cloth masks decreased by at least 34.7% at 10% extension, and by at least 60.9% at 20% extension Conclusions: The filtration efficiency of cloth masks could decrease after one to two machine washings, but will increase after four washings in comparison with their original performances. The filtration efficiency of cloth masks will decrease when they are expanded, such as when stretching over the nose during wearing status.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.53-63
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• 2022

Objectives: This study was designed to evaluate the filtration efficiency, inhalation resistance, and liquid resistance of commercial reusable masks in comparison to the performance of KF-AD masks (reference masks). Methods: Thirty-six masks were purchased from an online market. Filtration efficiency and inhalation resistance were determined in the same manner as in MFDS certification testing, respectively using TIL/IL & Filter Test 1300S (SFP Services, UK) and Breathing Resistance Analyzer DA2001 (Lambda Ray, South Korea). Results: Most of the filtration efficiencies found for the 19 masks were far lower than the test standard for KF-certified masks. Four masks met KF94 and three masks even met KF80. Most inhalation resistances were also much lower than the standard, with many almost one-half of the standard. In addition, all the masks except KF-AD masks did not pass the liquid resistance test. Conclusions: Although most of the filtration efficiency performance results found in this study for the reusable masks, which emerged as an alternative, were lower than the standard for health masks, multi-use masks can be used with a replacement filter inserted.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3274-3292
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• 2013

Unsupervised methods for image segmentation are recently drawing attention because most images do not have labels or tags. A topic model is such an unsupervised probabilistic method that captures latent aspects of data, where each latent aspect, or a topic, is associated with one homogeneous region. The results of topic models, however, usually have noises, which decreases the overall segmentation performance. In this paper, to improve the performance of image segmentation using topic models, we propose two topic masks applicable to topic assignments of homogeneous regions obtained from topic models. The topic masks capture the noises among the assigned topic assignments or topic labels, and remove the noises by replacements, just like image masks for pixels. However, as the nature of topic assignments is different from image pixels, the topic masks have properties that are different from the existing image masks for pixels. There are two contributions of this paper. First, the topic masks can be used to reduce the noises of topic assignments obtained from topic models for image segmentation tasks. Second, we test the effectiveness of the topic masks by applying them to segmented images obtained from the Latent Dirichlet Allocation model and the Spatial Latent Dirichlet Allocation model upon the MSRC image dataset. The empirical results show that one of the masks successfully reduces the topic noises.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.1011-1017
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• 2021

An effective measure to prevent the spread of COVID-19 is wearing masks in public places. This solution is highly recommended in many countries all over the world. The objective of this study is to identify the antecedents of citizens' intention to purchase masks during the COVID-19 pandemic. Based on the theory of planned behavior (TPB), the current study analyzes attitudes toward mask-purchasing, subjective norms, and perceived behavioral control, to assess their impact on intention to purchase masks. In total, six variables are examined: attitude toward mask-wearing, subjective norms, perceived behavioral control, perceived severity, perceived susceptibility, and the intention to wear masks. Data are collected from 243 respondents in Ho Chi Minh City, Vietnam. They were processed through by factor analysis and multiple regressions. The results report that all three factors positively affect citizens' intention to buy masks in the following ascending order: Attitude toward mask-purchasing, subjective norms, and perceived behavioral control. Our study is the first research that applies TPB to investigate citizens' intention to purchase masks to during the COVID-19 pandemic. Moreover, this study provides guidelines to the Vietnamese public managers to combat COVID-19 through the purchase of masks. Shopkeepers would be well advised to observe the intentions of consumers toward masks.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.4
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• pp.101-116
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• 2022

The purpose of this study is to understand the trends of fashion mask designs as a fashion item with characteristics to protect individual health and safety from harmful environments. To this end, the concept, the trend analysis of the domestic and foreign mask markets, the type, characteristics of functional masks, and the design trend of fashion masks were analyzed. Research methods included case studies and literaturte on mask design, fashion magazines, fashion brand websites, fashion collections, and promotional material. First, masks for personal safety were classified as protective function masks from the natural environment, functional masks by industrial groups, masks for protective functions from biohazards, and masks for protective functions from various external activities. Through this analysis, the design trends of fashion masks were analyzed. The functional orientation of structure and functionality, the environmental orientation of sustainable eco-friendly methods, the fashion orientation of individual fashion styling, and the social functional orientation tend to transmit social messages. In the harmful environment of everyday life, items such as fashion masks with functionality and fashion characteristics should be continuously studied to integrate functional and design characteristics that can contribute to the future fashion industry and the fashion market as a sense of unity and responsibility.

• Journal of Fashion Business
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• v.27 no.2
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• pp.52-69
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• 2023

Based on five types of health KF masks currently being commercialized, this study analyzed results of a survey of 316 male and female college students with experience in wearing health masks in Seoul metropolitan area. By identifying problems and improvement requirements according to current status of wearing health masks, results of this study could be used as basic data for designing ergonomic health mask with improved ease of wearing and satisfaction for human safety protection in the future. SPSS 26.0 statistical program was used for all data analyses, including post-hoc test, χ² test for cross-analysis, frequency analysis, independent samples t-test, ANOVA, and Duncan test. Considering that masks are worn for more than 8 hours a day on average, it is necessary to design masks considering materials, sizes of mask ear straps, elasticity and thickness of straps. The design should minimize contact with lips and cheeks with improved fit and comfort, blocking performance, and aesthetics. According to this survey, nearly 50% of respondents said they were willing to wear masks even after the end of COVID-19. Thus, it is necessary to perform research and improve masks to have excellent colors, designs, shapes, fit, and functions suitable for both pandemic and post-pandemic era when wearing masks is common.

• The Research Journal of the Costume Culture
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• v.31 no.1
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• pp.1-17
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• 2023

This study analyzed requirements for medical masks and difference in satisfaction based on demographic characteristics and side effects experience caused by wearing medical masks. Three factors related to requirements for medical masks were identified: wearing comfort and usability, blocking function for harmfulness, and design. As a result of the difference analysis for requirements of medical masks based on demographic characteristics, all three factors showed a significant difference in gender and occupation. Design did in age and monthly income. As a result of the presence or absence of breathing difficulties experience, design factor was significant. As a result of the presence or absence of skin trouble experience, wearing comfort and usability showed a significant difference. As a result of the difference in satisfaction with medical masks based on demographic characteristics and side effect experience caused by wearing medical masks, breathing, ear string tightness, blocking harmful substances, price, and over all wearing comfort showed a significant difference by gender, marital status, age, occupation, and monthly income, and the presence of absence of breathing difficulty experience and skin trouble experience, respectively. As a result of the interaction effect analysis between demographic characteristics and side effects experience caused by wearing medical masks, it showed a significant interaction effect between gender and monthly income, between marital status and monthly income, between monthly income and breathing difficulties experience, and between monthly income and skin trouble experience.

• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.68-73
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• 2023

Smoke masks have attracted great interests and have been supplied widely for the improvement of the safety during fire evacuation. However, there is not sufficient research on the practical utility, certification status and easy-donning about commercial smoke masks, therefore it is difficult to determine the actual usefulness of the smoke masks. In this study, we conducted a survey on users' perceptions and experiences about the smoke masks, and investigated the status of certification of 54 commercial smoke masks. We also performed donning tests and examined degrees of discomfort for 4 types of the smoke masks. Although 22% of 235 respondents had experienced the smoke masks before the test, and 23% of the respondents did not know the smoke masks, 93% of the respondents expected that the smoke masks could protect users from fire smokes and toxic gases. It was found that 41% of the commercial smoke masks did not certify according to domestic or overseas performance standards. Most certification standards have not effectively regulated maximum wearing time for the smoke masks. Only ASTM E 2952 and KFIS 024 had specific standards for the maximum wearing time of 30 s. As a result of donning tests for 4 types of smoke masks, the wearing time of the hood-type mask and self-contained smoke mask exceeded 30 s, therefore these types of smoke masks might increase the required safe evacuation time. On the other hand, it was also found that short education about the donning could reduce the wearing time by 19% and numbers of improper wearing by 89%.