• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.38-47
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• 2019

The most common cause of mouth breathing is obstacles caused by mechanical factors in upper airway. Mouth breathing could be consequently pathological cause of sleep-disordered breathing. Sleep-disordered breathing in children can cause growth disorders and behavioral disorders. The purpose of this study was to investigate relationship between upper airway and sleep-disordered breathing in children with mouth breathing. Twenty boys between 7 - 9 years old who reported to have mouth breathing in questionnaire were evaluated with clinical examination, questionnaires, lateral cephalometric radiographs, and portable sleep testing. This study assessed apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) for the evaluation of sleep-disordered breathing and was done to investigate the correlation between these values and the upper airway width measured by lateral cephalometric radiographs. There was no significant correlation with the size of the tonsils (p = 0.921), but the adenoid hypertrophy was higher in the abnormal group than in the normal group (p = 0.008). In the classification according to AHI and ODI, retropalatal and retroglossal distance showed a statistically significant decrease in the abnormal group compared to the normal group (p = 0.002, p = 0.001). As AHI and ODI increased, upper airway width tended to be narrower. This indicates that mouth breathing could affect the upper airway, which is related to sleep quality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.786-794
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• 2018

In recent years, in response to rapid technological change, technology planning activities are important for companies to cope with technological competition. However, Small and Medium Enterprises(SMEs) lack the resources and competence to establish their own technology roadmaps. Therefore, government-led roadmaps for SMEs have been proposed to support the R&D direction and R&D capabilities of SMEs. However, SMEs R&D policies are still not well linked with technology roadmaps and R&D programs. In other words, the size of R&D for SMEs is determined according to demand of SMEs regardless of strategic technology roadmap. In this study, we propose a investment prioritization model based on a technology road map to unify R&D investment policy. Using the decision model designed to prioritize strategic technology investments in the SME strategy roadmap, we conduct empirical analysis of strategic technologies in the advanced convergence and green manufacturing. AHP analysis was conducted after questionnaires on the importance of strategic technology and the importance of influential factors to 46 experts such as expert of research institutes and support organizations.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.569-575
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• 2021

This study analyzed the effect of forests on reducing particulate matter by investigating the particulate matter concentration and influencing factors between urban forest and traffic forest. The concentrations of particulate matter in Hongreung Experimental Forest (urban forest) and a forest (traffic forest) formed at the intersection of Cheongryangri Station in Dongdaemun-gu, Seoul were measured with the light scattering method instrument from January to November 2018. During the study period, the average PM₁₀ concentrations in the urban forest and the traffic forest were 12.5㎍/m³ and 15.7 ㎍/m³, respectively, and the average PM_2.5 concentrations were 16.6㎍/m³and 6.9 ㎍/m³, respectively. Comparing the concentration by the urban atmospheric measurement network of the Ministry of Environment and the concentration in urban forests showed that the reduction rate of PM₁₀ was 66.9±28.6% in urbanforest and 58.6±44.1% in traffic forest and that of PM_2.5 was 71.3±23.0% and 64.9±31.3%. The difference in the reduction rate of particulate matter is likely related to the size and structure of the urban forest, and the wind velocity is considered the reduction factor.

• The Korean Journal of Archival Studies
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• no.70
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• pp.157-187
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• 2021

Broadcasting and audiovisuals are the easiest audiovisuals to access in everyday life and are shared through the media by recording the times. Overseas, independent broadcasting and audiovisual archives are already in operation under the legal system. As the domestic broadcasting and audiovisual industries continue to grow in size and are drawing global attention, the establishment and operation of public broadcasting and audiovisual archives need to be discussed in more detail. In particular, it is clear that the legal device is a task that must be preceded as the basis for the establishment of public broadcasting and audiovisual archives. To this end, this study first looked at the Digital Archive Center, which was operated in the 2000s. In addition, the cause of the dismantling of the Digital Archive Center was considered as the absence of a legal device, and the case of the Institut national de l'audiovisuel(INA), which has been operating on a legal basis for a long time, was investigated. INA is a representative example of implementing a lead-based system in the broadcasting and audiovisual fields, and has been introduced several times through previous studies, but tends to be focused on user services. Therefore, in this study, the analysis was focused on legal factors supporting the operation of INA. Finally, in order to realize the Public Broadcasting and Audiovisual Archive discussed in the previous study, I would like to suggest a legal device for the establishment of Public Broadcasting and Audiovisual Archive in Korea.

• Journal of the Korean Society for information Management
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• v.37 no.4
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• pp.1-26
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• 2020

In today's increasingly data-intensive academic environment, data is becoming the foundation of academic communication as a research outcome rather than a research by-product. However, there is a limit to guaranteeing actual data reuse only by expanding the data supply or securing accessibility. In order to overcome this, it is necessary to understand the data reuse behavior and data needs in-depth. Therefore, this study attempted to identify the major data reuse behavior and data needs among researchers. To this end, the authors of KCI papers among the data reuse documents of the Korea Social Science Data Archive (KOSSDA) for the past 3 years were targeted. An in-depth interview was conducted with 12 researchers who accepted the interview. As a result, factors considered when reusing data were personal, economic, technical, and social aspects, and it was found that the data itself was used or contextual information of the data was used depending on the purpose of data reuse. The path to acquiring data is a web-based source of information, and a path through informal communication can also be found. In terms of the data needs, it was found that they prefer English, the United States, and institutional producers. Also they have a clear preference for quantitative data from an interviewer-filled interpersonal interview survey method, rich metadata along with raw data, and data that contains identification information. However, due to the lack of confidence in the value, it is negative for the use of data with controlled access and use, and it is difficult to confirm a clear preference because there is no similar data available for selection in terms of size and freshness.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.27-33
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• 2022

Sleep is an essential factor for living a healthy life, but most modern people complain of poor sleep. For these people, as the need for a means to simply evaluate and manage the quality of sleep increases, devices that can check the sleep state at home without monitoring by an examiner are being developed. The smart sleep mask, which is the subject of this usability test, provides bio-signal monitoring while sleeping so that you can conveniently measure and manage your sleep state for yourself. The purpose of this study is to evaluate the usability and safety of the smart sleep mask, to find and prevent potential factors related to errors in use that may occur, and to develop the comfort and safety of this product. As a result of the formative evaluation of the sleep mask prototype, it was reported that it was difficult to turn on the power and check the results, and that the sleep mask was not comfortable to wear. Different opinions were presented on the size and weight of the sleeping mask by people in different age groups.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.1-12
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• 2020

The study is to analyze the value of satisfaction of instructional process to university students and to verify the relationship between the factors that how students make the team for class activity and instructional effect. According to this, the purpose of this study is to analyze the effect of lecture-based instruction and the project-based learning and verify the component factor of project-based learning so that this study can suggest various ways to participate in classes actively. For this study, the students participating in the classes from this researcher were selected and it was analyzed with quantitative and qualitative research. The qualitative research was in progress for 15 weeks class from September to December 2019 and the survey was done at the last day of 15 weeks class and project. Frequency, difference, correlation and regression analysis were conducted through SPSS 23.0 with 80 copies of the questionnaire. The result of this study, at first, the instructional effect and satisfaction of satisfaction on project-based learning is higher than teacher-centered instruction. Second, the team cohesion and team-work is giving a huge impact on instructional effect and satisfaction. At last, project-based leaning makes students participate in the class. Enjoy and satisfy in the course of class participation regardless of the result. Based on these findings, we are looking for the ways to use the project-based leaning and provide the objective data for the planning and production of class program to improve the effectiveness of the class. In addition, we discussed the implications and limitations of this study as well.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.81-93
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• 2000

In a methodological approach to improve the processing performance of modulo exponentiation which is the primary arithmetic in RSA crypto algorithm, we present a new RSA hardware architecture based on high-radix modulo multiplication and CRT(Chinese Remainder Theorem). By implementing the modulo multiplier using radix-16 arithmetic, we reduced the number of PE(Processing Element)s by quarter comparing to the binary arithmetic scheme. This leads to having the number of clock cycles and the delay of pipelining flip-flops be reduced by quarter respectively. Because the receiver knows p and q, factors of N, it is possible to apply the CRT to the decryption process. To use CRT, we made two s/2-bit multipliers operating in parallel at decryption, which accomplished 4 times faster performance than when not using the CRT. In encryption phase, the two s/2-bit multipliers can be connected to make a s-bit linear multiplier for the s-bit arithmetic operation. We limited the encryption exponent size up to 17-bit to maintain high speed, We implemented a linear array modulo multiplier by projecting horizontally the DG of Montgomery algorithm. The H/W proposed here performs encryption with 15Mbps bit-rate and decryption with 1.22Mbps, when estimated with reference to Samsung 0.5um CMOS Standard Cell Library, which is the fastest among the publications at present.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.787-797
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• 2020

The marine officer plays a pivotal role in the shipping organization as a professional who performs a complex and diverse function. On the sea, unlike land duty, the possibility of turnover increases due to characteristics such as living in isolated spaces, continuous shift work during a set sailing period, high intensity work tension, stress, and social isolation. In this study, the impact of the organization's civic actions on the intention of turnover as a mediator of organizational immersion was divided into three groups of large companies, small and medium-sized enterprises, and public enterprises to check the differences between each category in a structural manner. Analysis showed that there were statistically significant differences between the groups in loyalty and turnover intention when the sub-factors of organizational commitment and organizational citizen behavior of the marine officer, and the size of turnover intention were included. Organization citizen behavior did not directly affect turnover intention, but when indirect effects were included, there was an effect through loyalty, and relationship-oriented organizational citizen behavior negatively affected turnover intention through loyalty. Excluding public enterprises, the non-standardization path coefficients were -0.229±0.117 and -0.319±0.068, respectively, showing a statistically significant effect in large companies and SMEs. These results indicate that in order to lower the employee turnover intention in large corporations and small and medium-sized shipping companies, it is necessary to consider not only organizational citizen behavior but also measures to increase organizational commitment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.126-134
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• 2020

In the case of an earthquake, the fluid storage structure generates hydraulic pressure due to the fluctuation of the fluid. At this time, the hydraulic pressure of the fluid changes not only the peaked acceleration of the earthquake but also the sloshing height of the fluid free water surface. Factors influencing this change in load include the shape of the seismic wave, the maximum seismic strength, the size of the fluid storage structure, the width of the structure, and the height of the fluid. In this study, the effect of the ratio between the height of the fluid and the width of the structure was investigated on the fluctuation characteristics of the fluid. 200mm and 140mm of fluid were placed in a water storage tank with a width of 500mm, and a real seismic wave was applied to measure the shape of the fluctuation of the fluid free water surface. The similarity between the experiment and the analysis was verified through the S.P.H(Smoothed Particle Hydrodynamic) technique, one of the numerical analysis techniques. It was confirmed that the free water surface of the fluid showed a similar shape, through comparison of experiment and analysis. And based on this results, SPH technique was applied to analyze the fluctuation shape of the fluid free water surface while varying the ratio between the fluid height and the structure width. An equation to predict the maximum and minimum heights of the fluid free water surface during an earthquake was proposed, and it was confirmed that the error between the maximum and minimum heights of the fluid free water surface predicted by the proposed equation was within a maximum of 3%.