• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.20.1-20.6
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• 2016

Background: Most of cleft lip and palate patients have the esthetic and functional problems of midfacial deficiencies due to innate developmental tendency and scar tissues from repeated operations. In these cases, maxillary protraction is required for the harmonious facial esthetics and functional occlusion. Case presentation: A 7-year old boy had been diagnosed as severe maxillary constriction due to unilateral complete cleft lip and palate. The author tried to correct the secondary deformity by early distraction osteogenesis with the aim of avoiding marked psychological impact from peers of elementary school. From 1999 to 2006, repeated treatments, which consisted of Le Fort I osteotomy and face mask distraction, and complementary maxillary protraction using miniplates were performed including orthodontics. But, final facial profile was not satisfactory, which needs compromising surgery. Conclusions: The result of this study suggests that if early distraction treatment is performed before facial skeletal growth is completed, an orthognathic surgery or additional distraction may be needed later. Maxillofacial plastic and reconstructive surgeons should notify this point when they plan early distraction treatment for cleft maxillary deformity.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.7-15
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• 2014

This paper proposed a recognition algorithm of human facial expressions using the PCA and the template matching. Firstly, face image is acquired using the Haar-like feature mask from an input image. The face image is divided into two images. One is the upper image including eye and eyebrow. The other is the lower image including mouth and jaw. The extraction of facial components, such as eye and mouth, begins getting eye image and mouth image. Then an eigenface is produced by the PCA training process with learning images. An eigeneye and an eigenmouth are produced from the eigenface. The eye image is obtained by the template matching the upper image with the eigeneye, and the mouth image is obtained by the template matching the lower image with the eigenmouth. The face recognition uses geometrical properties of the eye and mouth. The simulation results show that the proposed method has superior extraction ratio rather than previous results; the extraction ratio of mouth image is particularly reached to 99%. The face recognition system using the proposed method shows that recognition ratio is greater than 80% about three facial expressions, which are fright, being angered, happiness.

• Journal of Platform Technology
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• v.10 no.3
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• pp.44-50
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• 2022

Research on facial age estimation is being actively conducted because it is used in various application fields. Facial images taken in various environments often have occlusions, and there is a problem in that performance of age estimation is degraded. Therefore, we propose age estimation method by creating an occluded part using image extrapolation technology to improve the age estimation performance of an occluded face image. In order to confirm the effect of occlusion in the image on the age estimation performance, an image with occlusion is generated using a mask image. The occluded part of facial image is restored using SpiralNet, which is one of the image extrapolation techniques, and it is a method to create an occluded part while crossing the edge of an image. Experimental results show that age estimation performance of occluded facial image is significantly degraded. It was confirmed that the age estimation performance is improved when using a face image with reconstructed occlusions using SpiralNet by experiments.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.53-60
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• 2009

Maxillary deficiency, anterior cross bite, constriction of maxillary arch, malaligned teeth are frequently observed in patients with cleft lip and palate. Surgery and orthodontics, combined intervention are needed to correct maxillary deficiency. Distraction osteogenesis that currently used has many advantages like less relapse tendency, more advancement of maxilla, capable in growing patients. In case 1, 18 years old girl with BCLP had severe midfacial deficiency and multiple missing of teeth. LeFort I osteotomy, followed by maxillary distraction osteogenesis utilizing rigid external distraction device(RED) system, was performed. After a 6-day latency period, distraction proceeded at a rate of 1mm per day (at 1st week, 1.5mm/day). Total advancement was 19mm. The RED device left in place for the additional 4 weeks for consolidation. After the RED device was removed, face mask was applied with elastic traction for 5 weeks. After achieving acceptable facial appearance and occlusion, orthodontic appliance was removed. The results after 4 years follow-up was sustained pretty well without aggravation of velopharyngeal function. In case 2, 22 years old man with UCLP had severe midfacial deficiency and palatally erupted upper 2nd premolars due to arch length discrepancy, but the anterior segment of maxillary did not show constriction and crowding. patient had no arch width discrepancy, crowding was concentrated on premolar region. Segmental LeFort I osteotomy was performed. After a 6 - day latency period, using internal distraction device, distraction proceeded at a 0.5mm per day(at 1st week, 0.75 - 1 mm/day). Total advancement was 15mm. After internal distraction device was removed, face mask was applied with elastic traction for 4 weeks. After surgical-orthodontic treatment, facial appearance and occlusion was improved pretty good, and after 46 months follow-up the result was retained well.

• Journal of Korean Society for Quality Management
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• v.46 no.2
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• pp.301-310
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• 2018

Purpose: The purpose of this study is to investigate the effect of work intensity on fit factor and affective quality of the dustproof Background: Among the victims who suffer pneumoconiosis due to the inhalation of toxic substances or the lack of oxygen during the work, the proportion of the victims is larger than the other causes. Wearing a respirator may prevent pneumoconiosis, but it can be hazardous to workers because of the leakage through filters, cartridges, exhaust valves, broken parts, and face-to-face contact. Despite leakage through the contact area between the mask and the face has various causes such as the wearer's activity, sweat accumulation, facial shape, etc., There is a lack of relevant research and regulation compared to developed countries that have already institutionalized the law 30 years ago and give the right to sell through a test Method: The work intensity was adjusted by walking or running at 6km/h and 11km/h on the treadmill, and tasks were defined with reference to the test procedure and the exercise sequence applied in the face leakage test of the dustproof mask. And fit factor was measured objectively using 'Respirator Fit Tester 8038' which measures fit factor calculated by dividing the number of dust present outside the mask by inside the mask. In addition, affective quality was classified by the ease of use, ease of breathing, and ease of wearing, and was measured using the 5-point likert scale questionnaire. Results: There was a significant difference in fit factor, ease of breathing, and wearing convenience according to work intensity and no significant difference in ease of use(${\alpha}=0.01$). And when the work intensity was high, fit factor, ease of breathing, and wearing convenience were all lower than when the work intensity was low. Conclusion: In Korea, it is necessary to consider consideration of the work intensity when testing the leakage rate of the face part for safety certification of the respiratory protective equipment, When developing a mask, it should be possible to maintain high adhesion even under intense, active situation and high temperature conditions by selecting materials, improving the wearing style, and expanding the adjustable range.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.269-278
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• 2019

This study is intended to present the direction of art mask design development and help people's life care by producing an art mask with the motif of the characteristic of abjection concept. It went through the definition and characteristics of abject and abjection focusing on previous research, professional books and art works. The characteristics of abjection based on theoretical research are to express death with dead bodies and skulls, including the dismantling of ideal beauty standards, the expression of fragmented bodies, and the expression of sick and alienated bodies. This researcher produced 6 research works by combining the fascinating abjection, induced by ugly and disgusting abject, to design factors. These works fragmented each part of the facial form by the cutting and dismantling, and made viewers feel the abjection by giving a grotesque deformation. The results obtained through the research works are as follows. First, It was found that the abjection characteristics-applied works was helpful in the treatment of the mental wound of modern people. Second, the production of works based on the abjection characteristics paved the way to expand the scope of art mask design concepts and establish the new design ideas. Third, the application of the motif using the abjection characteristics to the art mask design showed that the use of various objects could express creative designs and secure diversity in using materials. In the future, this researcher hopes that such research will be used as the basic data of the follow-up study on art mask design, and it will help develop art mask designs.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.569-576
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• 2000

The GST can extract the position of facial features without a prior information in an image. However, this method requires a plenty of the processing time because the mask size to process GST must be larger than the size of object such as eye, mouth and nose in an image. In addition, it has the complexity for the computation of middle line to decide facial features. In this paper, we proposed two methods to overcome these disadvantage of the conventional method. First, we used the reduced image having enough information instead of an original image to decrease the processing time. Second, we used the extracted peak positions instead of the complex statistical processing to get the middle lines. To analyze the performance of the proposed method, we tested 200 images including, the front, rotated, spectacled, and mustached facial images. In result, the proposed method shows 85% in the performance of feature extraction and can reduce the processing time over 53 times, compared with existing method.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.76-79
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• 2014

Face recognition is very challenging because of the unexpected changes of pose, expression, and illumination. Facial detection in the mobile environments has additional difficulty since the computational resources are very limited. This paper discusses face detection based on frequency domain matched filtering in the mobile environments. Face detection is performed by a linear or phase-only matched filter and sequential verification stages. The candidate window regions are selected by a number of peaks of the matched filtering outputs. The sequential stages comprise a skin-color test and an edge mask filtering tests, which aim to remove false alarms among selected candidate windows. The algorithms are built with JAVA language on the mobile device operated by the Android platform. The simulation and experimental results show that real-time face detection can be performed successfully in the mobile environments.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.282-288
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• 2022

Facial masks have become indispensable in daily life to prevent infection and spread through respiratory droplets in the era of the corona pandemic. To understand how effective two different types of masks (i.e., KF-94 mask and dental mask) are in blocking respiratory droplets, i) we preferentially analyze wettability characteristics (e.g., contact angle and contact angle hysteresis) of filters consisting of each mask, and ii) subsequently observe the dynamic behaviors of microdroplets impacting at high velocities on the filter surfaces. Different wetting properties (i.e., hydrophobicity and hydrophilicity) are found to exhibit depending on the constituent materials and pore sizes of each filter. In addition, the pneumatic conditions for stably and uniformly dispensing microdroplets with a certain volume and impacting behaviors associated with the impacting velocity and filter type change are systematically explored. Three distinctive dynamics (i.e., no penetration, capture, and penetration) after droplet impacting are observed depending on the type of filter constituting the masks and droplet impact velocity. The present experimental results not only provide very useful information in designing of face masks for prevention of transmission of infectious respiratory diseases, but also are helpful for academic researches on droplet impacts on various porous surfaces.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.432-439
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• 2004

Korean certification regulation for particulate filtering respirators requires inward leakage (IL) test as European Standards (EN) and the standard levels of regulation are the same as those of EN. This study was conducted to evaluate particulate filtering respirators being commercially used in the market by using IL and assess the characteristics of IL. The study began with discussing the concept of IL, comparison of IL with fit test, and IL measurement method. Three brands of half masks and 10 brands of filtering facepieces (two top class, four 1st class and four 2nd class), total 13 brands respirators, and 10 test panels (subjects) who were classified in 9 facial grids in accordance with face length and lip length, were selected for IL test. IL tests were conducted in the laboratory of 3M Innovation Center which was established by EN standard. As expected ILs of half masks were lower than those of filtering facepiece mask. ILs of half masks and some filtering facepieces were significantly different in manufacturers. ILs of 1st class filtering facepieces were found to be much more than those of 2nd class and thus the result would cause wearers to get confused to select a mask. Four of six brands being no compliance with standards were thought that they should be tested again for certification because of a lot of differences from standards. There were no significant differences among ILs of five exercises. In 6 out of 13 brands lognormal distribution of ILs may be a better fit distribution and in 7 brands both lognormal and normal distributions were rejected. The result indicates that geometric mean may be better than arithmetic mean to establish standard.