• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.45-56
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• 2022

The purpose of this study is to evaluate changes of occlusion following the placement of preformed metal crown in the permanent first molar affected by severe caries or hypomineralization. The study was conducted on 24 patients who met the criteria among the patients with occlusion in the permanent first molar reaching the occlusal plane. Restorative treatment was performed on one first molar using preformed metal crown. Before treatment, immediately after treatment, after 4 weeks, and after 8 weeks, the T-scan III was used for measuring distribution of bite force at the maximum intercuspal position, and overbite was measured with digital vernier calipers and change of dental midline was surveyed. After 8 weeks, questionnaires survey was conducted. In most cases, immediately after treatment, the distribution of bite force between the restored side and non-restored side of arch was reversed compared to before treatment, and the overbite was decreased. However, after 4 weeks, bite force of the left and right side was balanced and the distribution of bite force on the restored and non-restored permanent first molars had similar values. Also, the changed overbite and midline were returned to pre-treatment status and there was no significant temporomandibular joint and masticatory discomfort after treatment. In this study, it was confirmed that spontaneous occlusal equilibrium was achieved one month after the placement of preformed metal crown.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.435-448
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• 2022

Objectives: As the time spent wearing masks has increased with spread of COVID-19, various research related to masks have been reported. However, there are still few experiments on the physiological response of the body to wearing industrial dust masks in South Korea. Considering the actual working hours at the work site, it is necessary to investigate the comfort of industrial dust masks. Therefore, this study aims to confirm the change in subjective discomfort level according to the wearing time for industrial dust masks in South Korea that have been certified for safety by KCS. Methods: This study evaluated subjective discomfort level over four hours. The experimental conditions were five types: not worn (control group), special grade, first grade, second grade (with valve), and second grade (without valve). The subjective discomfort levels were classified for breathing, warmth (body and face) and wetness (body and face). Subjects recorded their discomfort level on a checklist every one hour. Results: In special grade and second grade (without valve), the discomfort level in terms of breathing, warmth (face), and wetness (face) was significantly higher than that of the control group. However, the effects of all kinds of industrial dust masks on the discomfort level in the body were low. Conclusions: Since this study was conducted on subjects working in an office with a comfortable working environment, it is difficult to apply it to workers at actual industrial sites. However, it is considered meaningful as the first clinical study to evaluate the subjective level of discomfort over a long time for domestic industrial dust masks that have been certified for safety by KCS.

• Journal of Platform Technology
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• v.10 no.2
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• pp.10-19
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• 2022

Moving assistant devices for people who are difficult to move are becoming electric-powered and automated. These moving assistant devices are not suitable for moving stairs at which the height between floor surfaces is different because these devices are designed and manufactured for flatland moving. An electric-powered and automated moving assistant device should change direction or stop when it approaches stairs in a movement direction. If the user or automatic control system does not change direction or stop in time, a moving assistant device can roll over or collide with stairs. In this paper, we propose a stairs detection method by using oblique distance measured by one sensor tilted to flatland. The method proposed in this paper can detect upward or downward stairs by using a difference between a predicted and measured oblique distance in considering a tilted angle of a sensor for measuring an oblique distance and installation height of the sensor on a moving object. Before the device enters a stairs region, if our proposed method provides information about detected stairs to a device's controller, the controller can do adequate action to avoid the accident.

• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.55-65
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• 2022

The purpose of this paper was to investigate the relationship between cybersickness symptoms and visual function and to determine whether visual perception training is effective in reducing symptoms of cybersickness. The study subjects were healthy adult males who experienced the same virtual reality program for 15 minutes. Afterwards, the VR satisfaction score and cybersickness level were measured and classified into a comfortable virtual reality program viewer group (CVR group, 20 people) and an uncomfortable virtual reality program viewer group (UVR group, 20 people). Visual function test was performed on all subjects, and the vision therapy training program was applied to the UVR group once a week for 40 minutes 12 times, and then the visual function and SSQ questionnaire were re-evaluated. Subjects with diplopia were 55% in the UVR group and 5% in the CVR group, which was significantly higher in the UVR group, there were differences in stereopsis, exophoria, near point convergence(p<.01) and vergence function(p<.001) between the two groups. After vision therapy, changes in SSQ, stereopsis, near point convergence, and vergence function of UVR user group were positively changed(p<.01). Therefore, cybersickness symptoms are related to visual function, it seems that the vision therapy can be used as a way to alleviate the symptoms of cybersickness.

• Journal of Naturopathy
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• v.9 no.2
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• pp.46-56
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• 2020

Purpose: This study proposes a concert oriented music therapy (COMT) program which takes into account the personal and social factors of depression, and its clinical effects were validated on elderly persons with visual impairments who were susceptible to depression. The experiment was conducted on 34 elderly persons with visual impairments, randomly allocated to either the experimental group (n = 15) or the control group (n = 19). The COMT program was applied 20 times in total to the experimental group for 110 minutes every other week, for a duration of 10 months. The depression level was evaluated using the Korean form of the Geriatric Depression Scale (KGDS). The experimental results showed that the average KGDS score in the experimental group decreased by 4.1 points (19.4%), from 21.0 to 16.9, whereas it increased by 1.16 points (5.8%), from 19.95 to 21.11, in the control group. The reduction in the depression level was significant for the following 4 depression factors : decreased social interest (40%), negative thinking and the unhappiness feeling (20%), emotional discomfort (16.3%), and cognitive dysfunction (7.6%), whereas it was negligible in the factors of physical weakening and decreased vitality. The COMT program reduced the KGDS scores of the experimental group regardless of their experience in musical performance. In conclusion, the proposed COMT program proved to be efficacious in alleviating depression in elderly persons with visual impairments. In particular, it proved highly effective in helping with decreased social interest, namely, the social factor of depression which is not properly considered in existing music therapy methods.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.87-94
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• 2022

In this study, 61 patients who underwent coronary angiography from March 2018 to August 2019 were divided into Group I (Radial, n=34 patients) and Group II (Femoral, n=27 patients), and compared and analyzed methods using radial and femoral arteries when coronary angiography was performed. As a result of comparative analysis, Catheter usage was reduced in the examination using radial artery, and in the abnormal shape of blood vessels, Loops arterial abnormalities were more in the radial artery (20.6% vs, 0%, p<0.05), and it was found that the abnormal shape of the radial vessels increased with age. 60s, 70s, 80s, 90s or older (0%, 18.2%, 25.0%, 100%)

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.279-290
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• 2021

As the university's academic management was not carried out smoothly due to COVID-19, and most of them were conducted as non-face-to-face classes, students' dropout is steadily increasing. In this study focus group interviews were conducted to analyze physics students and professors' recognition of the COVID-19 non-face-to-face class environment. Based on the results, the implications of non-face-to-face classes for physics education were presented. Physics students described their feelings about un-tact teaching as 'the class in which the body is comfortable but the mind is uncomfortable', 'a person who is smarter than me seems to explain a book, reading it' and 'a short clip lecture which may be comfortable but cause losses to me', while the professors also described them as 'a fully transformed class system' and 'a online class putting much burden on me'. Regarding school dropout, students said that the concerns about dropout during non-face-to-face classes were deepened about transfer or transfer. The professors said that the department atmosphere had lost vitality due to the increase in non-face-to-face classes and academic dropouts, and had a lot of worries because of the recruitment rate and external university evaluation. The implications of the COVID-19 non-face-to-face class situation for physics education suggest that it is required to strengthen the interaction between professors and students, finding ways to enhance the sense of reality to supplement laboratory classes and giving opportunities to professors to share their pedagogical contents knowledge in physics.

• 지역과문화
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• v.7 no.1
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• pp.99-126
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• 2020

This study aimed to investigate the effects of multicultural complexes on activating local culture. Prior studies that discuss activating local culture through multicultural complexes focus on literature reviews or quantitative research methods, which do not incorporate the detailed and practical opinions of the users of the location. Therefore, this study collected detailed information through in-depth interviews with users, and investigated the future development methods of multicultural complexes based on the obtained information. It focused on the Asia Culture Center (ACC) in Gwangju, which is considered a prime example of a multicultural complex, and conducted in-depth interviews with citizens who have lived in Gwangju for at least five years as well as visited the ACC to investigate the research question from a detailed perspective. The results revealed that although the citizens of Gwangju have a positive perception of the functions of ACC as a cultural space representing the city that activates the local culture, they perceive it as partially insufficient to be considered a multicultural complex. Major findings included the following: the contents of the ACC do not have a mass appeal, its inflexible hours of operation inconvenience visitors, and the contents available for visitors lack in quantity and quality. Therefore, in order for the ACC to appeal as a successful multicultural complex, it is necessary to cooperate with the members of the community to investigate their needs with respect to the contents and location, and prepare strategic plans to satisfy those needs.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.64-75
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• 2022

The method of accessing multiple control systems in the OT control network centered on operation technology uses the operator authentication technology of each control system. An example is ID/PW operator authentication technology. In this case, since the OT control network is composed of multiple control systems, operator authentication technology must be applied to each control system. Therefore, the operator must bear the inconvenience of having to manage authentication information for each control system he manages. To solve these problems, SSO technology is used in business-oriented IT networks. However, if this is introduced into the OT control network as it is, the characteristics of the limited size of the OT control network and rapid operator authentication are not reflected, so it cannot be seen as a realistic alternative. In this paper, a public key-based authentication mechanism was newly proposed as an operator authentication technology to solve this problem. In other words, an integrated public key certificate that applies equally to all control systems in the OT control network was issued and used to access all control systems, thereby simplifying the authentication information management and making access to the control system more efficient and secure.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.1-18
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• 2022

This study critically analyzed the user experience (UX) of mobile applications, focusing on the advertising platforms of mobile applications for culture and arts content. This study aims to examine the direction for growth of the related mobile applications and propose alternative approaches to improve usability. In this study, a mobile app named 'Moviepre' was selected, and a heuristic evaluation was performed for in-depth exploration. For the selected case, the UX Honeycomb model was reconstructed to analyze useful, usable, desirable, findable, accessible, and credible elements of the case. First, since the users' preference for the price factor did not show a significant correlation with the usefulness of the content and the interface, it is necessary to make sure that the mobile application has unique values to gain a competitive advantage in the market. Second, by adopting customer path stages for analysis, the result indicated that users continuously interact with the service from the first moment they are aware of the mobile application. Third, if the user feels uncomfortable, it is likely that these factors hinder the establishment of a long-term relationship between the users and the mobile application. Finally, brand identity should be clearly established, and brand image strategy needs to be developed to satisfy users' expectations that high-quality culture and arts content will be available through the mobile application.