• Child Health Nursing Research
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• v.27 no.3
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• pp.276-285
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• 2021

Purpose: This study investigated the factors that influence depression in adolescents diagnosed with asthma in South Korea, providing basic data supporting efforts to improve adolescents' mental health. Methods: Multiple regression analysis was conducted on 4,020 subjects who had been diagnosed with lifelong asthma among the 57,303 respondents to the 15th Korea Youth Risk Behaviour Web-Based Survey from 2019. Results: The participants were more likely to have depression if they were female, in middle school, their academic achievement was poor, they were drinkers or smokers, if they felt a very high amount of stress, and if they experienced very inadequate recovery from fatigue. Adolescents with asthma were 9.00 times more likely to experience depression when they felt a very high amount of stress (95% confidence interval [CI]=5.51-14.69, p<.001) than when they felt no stress. Conclusion: Given these factors, measures to improve the mental health of adolescents should be developed and expanded, especially to decrease their stress levels. A separate program that is different from the school's regular health curriculum should be developed to manage the stress levels of adolescents with asthma, such as an after-school program or a program conducted at a local community centre.

• International Area Studies Review
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• v.20 no.4
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• pp.23-36
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• 2016

This studies the relationship between ODA and export performance of donor countries in Myanmar. This study analyzes 19 donor countries from 2002 to 2014 by using gravity model. The results show that ODA improves the export performance of donor countries in Myanmar in the period. The larger the amount of ODA, the larger the exports in Myanmar. And the rate of increase of ODA is also important in determining the export performance. These imply that ODA increases donor's export directly as well as indirectly by improving the relationship between donors and receivers. These results are important for Korea that is increasing ODA into Myanmar. Korea should search for a mode of ODA supporting as well as the amount of ODA.

• Earthquakes and Structures
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• v.22 no.3
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• pp.277-287
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• 2022

The ancient underground cities are a collection of self-supporting spaces that have been manually excavated in the soil or rock in the past. Because these structures have a very high cultural value due to their age, the study of their stability under the influence of natural hazards, such as earthquakes, is very important. In this research, while introducing the underground city of Ouyi Nushabad located in the center of Iran as one of the largest man-made underground cities of the old world, the analysis of dynamic stability is performed. For this purpose, the dynamic stress-displacement analysis has been performed through numerical modeling using the finite element software PLAXIS. At this stage, by simulating the Khorgo earthquake as one of the large-scale earthquakes that occurred in Iran, with a magnitude of 6.9 on the Richter scale, dynamic analysis by time history method has been performed on three selected sections of underground spaces. This study shows that the maximum amount of horizontal and vertical dynamic displacement is 12.9 cm and 17.7 cm, respectively, which was obtained in section 2. The comparison of the results shows that by increasing the cross-sectional area of the excavation, especially the distance between the roof and the floor, in addition to increasing the amount of horizontal and vertical dynamic displacement, the obtained maximum acceleration is intensified compared to the mapping acceleration applied to the model floor. Therefore, preventive actions should be taken to stabilize the excavations in order to prevent damage caused by a possible earthquake.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.4
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• pp.277-288
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• 2002

Seven finite element models were constructed in mandible having single screw-type implant fixture connected to the premolar superstructure, in order to evaluate how the length, diameter and platform shape of a screw-type fixture influence the stress in the supporting tissue around fixtures. Each finite element model was varied in terms of length, diameter, and platform shape of the fixture. In each model, 250N of vertical load was placed on the central pit of an occlusal plane and 250N of oblique load placed on the buccal cusp. The stress distribution in the supporting tissue and the other components was analysed using 2-dimensional finite element analysis and the maximum von Mises stress in each reference area was compared. Under lateral loading, the stress was larger at the abutment/fixture interface, and in the crestal bone, compared to the stress pattern under vertical loading. The amount of stress at the superstructure was similar regardless of the length, diameter and platform shape of a fixture. Around the longer fixture, the stress was decreased at the bone crest and subjacent cancellous bone and increased in the cancellous bone area apical to the fixture. Around the wider fixture, the stress was decreased at the abutment/fixture interface, and the bone crest and increased in the cancellous bone area apical to the fixture. Around the fixture having wider platform, less stress was produced at the abutment/fixture interface and the upper part of the cortical bone, compared to the fixture having standard platform. In conclusion, the stress distribution of the supporting tissue was affected by length, diameter, and platform shape of a fixture, and the fixture which was larger in diameter and length could reduce the stress in the supporting tissues at the bone-fixture interface and bone crest area.

• Journal of Korea Technology Innovation Society
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• v.20 no.3
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• pp.642-663
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• 2017

The purpose of this study is to investigate the factors that affect professor startups and their performances in Universities in Korea. We included 5 categories of factors: University's size and reputation, University's technology commercialization staff number and startup deregulation, University's resources for research and technology commercialization, University's patents and professors' publication, and student startups. We analyzed 150 Universities, using Korean government's Academyinfo database, and additional data for University ranking and government's projects for University startups. Our analysis shows that Universities' fund amount for research and technology commercialization, Universities' amount of patents give a positive impact on Universities statistically significantly, while Universities' size or reputation does not. In addition, the amount of patents and startup projects funded by the government give a significantly positive impact on the annual sales of the professor startups. Furthermore, student startups are in a positive relationship with professor startups and their sales, showing a synergy effect between the two startup groups in Universities. The result implies that Universities and government need to focus on supporting patenting activities, providing technology commercialization funds, and collaboration activities between professors and students for their startup activities.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.69-74
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• 2006

Recently, spillways are need to control stable water level for supporting main dams because of floods by unusual change of weather such as Typhoon Rusa. This study has been focused on the amount of leakage through the rock mass distributed fractures and joints under the opened emergency spillway. It is very important to evaluate the amount of leakage as these affect stability of spillway by interaction between effective stress and pore pressure. The commercial program MAFIC has been used for analyzing groundwater flow in fractured rock mass. The results showed that the values of range, average and deviation of leakage were $2.85\sim\;3.79\times10^{-1}$, $3.32\times10^{-1}$ and $1.70\times10^{-2}\;m^3/day/m^2$ respectively. Secondary, we have estimated the effect of grouting after the transmissivity$(T_f)$ of joint 1 as main pathway of leakage known from above results was changed from $1.78\times10^{-7}$ to $1.59\times10^{-9}\;m^2/s$. The results showed that the values of range, average and deviation of leakage were $7.80\times10^{-4}\sim1.53\times10^{-3}$, $1.18\times10^{-3}$ and $1.32\times10^{-4}\;m^3/day/m^2$ respectively. As the result, the amount of leakage after grouting has been decreased by a ratio of 1 to 277.

• Journal of Digital Contents Society
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• v.17 no.2
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• pp.89-96
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• 2016

SVC(Scalable Video Coding), which is one form among video encoding technologies, makes video streaming with the various frame rate, resolution, and video quality by combining three different scalability dimensions: temporal, spatial, and video quality scalability. As the above SVC-encoded video streaming consists of one base layer and several enhancement layers, and a wireless AP(Access Point) chooses and sends a suitable layer according to the received power from the receiving terminals in the changeable wireless network environment, the receiving terminals supporting SVC are able to receive video streaming with the appropriate resolution and quality according to their received powers. In this paper, after the performance analysis for the received power, packet loss rate, PSNR(Required Peak Signal to Noise Ratio), video quality level and amount of received video data based on the number of SVC layers was performed, an efficient method for selecting the number of SVC layer satisfying the RSNR and minimizing the amount of received video data is proposed.

• Journal of the Korean Chemical Society
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• v.20 no.6
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• pp.494-499
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• 1976

The extraction-polarographic method applied to the determination of micro amount of chromium (Ⅵ). Chromium(Ⅵ) was extracted into methylisobuthylketone(MIBK) layer containing diethyldithiocarbamate(DDTC) as Cr(Ⅲ)-DDTC complex from acetate buffered aqueous, solution of pH 5.4 and the direct current polarogram for the extract was recorded after addition of sodium perchlorate as supporting electrolyte. The reduction current was diffusion controlled. And the half wave potential of this reduction wave was -0.81 volt vs. SCE. The diffusion current was proportional to the chromium concentraticn in aqueous solution in the range of 8∼160 ppm. And the chromium(Ⅵ) could be selectively determined in the presence of chromium(Ⅲ), since the chromium(Ⅲ) did not interfere up to twice the amount of chromium(Ⅵ). Many of other metals such as Mn(Ⅱ), Cu(Ⅲ), Zn(Ⅱ), Mg(Ⅱ), Ni(Ⅱ) and Ag(Ⅰ) were found to have no effect even when present in 1000 times the amount of chromium (Ⅵ).

• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.115-118
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• 1979

The photochemical reactions and spectral properties of 1,1-diphenyl-2-vinylcyclopropane were studied. Upon direct irradiation of the compound at 253.7nm, 1,1-diphenylethylene was formed as a major product along with a small amount of 4,4-diphenylcyclopentene. Sensitized photoreactions showed quite a different phenomena from those of conjugated dienes supporting the spectral results that the cyclopropane ring does not transmit the conjugation in the compound.

• Journal of the Korean Institute of Rural Architecture
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• v.5 no.1
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• pp.1-11
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• 2003

The purpose of this study is to investigate and analyze the present state of elementary school libraries in Daejeon Metropolitan City. For this 50 schools are surveyed by questionnaires on two groups of teachers, those that take charge of school library and those who do not. As a results of this research following issues are emerged. First, the present state of surveyed school libraries is below standard with regard to the amount of books and size and it is required to improve these poor conditions. Second, the space programs are not sufficient to conduct enlarging scope of school libraries, which is conspicuous in spaces for affording librarians, supporting various activities and serving user's convenience. Third, in spite of poor conditions in school library facilities, respondents' satisfaction rate is not so low and there's no obvious demand for diversity of spaces.