• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.75-88
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• 2023

The aim of this retrospective study was to evaluate the demographic characteristics of pediatric dental patients who underwent dental treatment under general anesthesia (DTGA) at the Seoul National University Dental Hospital from January 2011 through December 2020 and compare the patterns of repeated DTGA between dental patients with severe disabilities (DSD) and non-DSD (healthy or medically compromised patients without DSD). There were 1,857 DTGAs among 1,719 patients (mean age = 5.1 years; males = 59.3%; ASA 2 or above = 52.9%; DSD = 26.8%). Overall, 6.6% of patients underwent repeated DTGA, and the rate of repeated DTGA over a 10-year period was 7.4%. ASA 2 or above (p < 0.0001) and DSD (p < 0.0001) were more likely to undergo repeated DRGA compared to ASA 1 and non-DSD. At both GA1 and GA2, DSD received significantly more restorative treatment on permanent teeth than non-DSD (p = 0.002, p < 0.0001, respectively). There has been an increasing demand for DTGA in pediatric dentistry over the last 10 years. Regular check-ups and preventive oral health care are necessary for pediatric dental patients with severe disabilities to reduce the possibility of repeated DTGA.

• Journal of Wetlands Research
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• v.25 no.3
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• pp.205-212
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• 2023

This study was attempted to find out how the ecological niche and interspecies relationship of Quercus aliena and Q. serrata, which are the main constituents of potential natural vegetation along the riverside of mountains in Korea, under climate change conditions. To this end, soil moisture and soil nutrients were treated with 4 grad ients under climate change conditions with elevated CO₂ and temperature, plants we re harvested at the end of the growing season, growth responses of traits were measured, ecological niche breadth and overlap were calculated, and it was compared with that of the control group(ambient condition). In addition, the relationship between the two species was analyzed by principal component analysis using trait values. As a result, the ecological niche breadth of Q. aliena was wider than that of Q. serrata under the moisture environment conditions under climate change. Under nutrient conditions, the ecological niche of the two species were similar. In addition, the ecological overlap for soil moisture of Q. aliena and Q. serrata was wider than the soil nutrient gradient under climate change. The species with traits in which the increase in ecological niche breadth due to climate change occurred more than the decrease was Q. aliena in both water and nutrient gradients. And in the responses of the population level, due to climate change, the adaptability of Q. aliena was higher than that of Q. serrata under the soil moisture condition, but the two species were similar under the nutrient condition. These results mean that the competition between the two species occurs more severely in the water environment under climate change conditions, and at that time, Q. aliena has higher adaptability than Q. serrata.

• Journal of the Daesoon Academy of Sciences
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• v.33
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• pp.219-255
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• 2019

'Dao' is an important research subject as it is the main term for 'ultimate reality' in East Asian religious thought. Understanding the concept of 'Dao' is essential to reach the state of 'Perfected Unification with Dao,' the ultimate aspiration in Daesoon Thought. The meaning of 'Dao' can vary such as 'Dao' meaning 'way', which was first introduced in Jinwen. There is also the 'Dao' of yin and yang, and Dao used to mean human obligation, or Dao meaning the way of Heaven. These can also be classified into five categories: Constant Dao, Heavenly Dao, Divine Dao, Human Dao, and the Dao of Sangsaeng. Every natural phenomenon of birth, growth, and death in the universe operates under the patterns of Heaven and Earth. Therefore, Constant Dao in Daesoon Thought is the ultimate pattern underlying human action and the operations of Heaven and Earth. These apply not only to the natural and the divine world but also to the human world. It can be said that 'Rather than natural law or moral symbol of the world, 'Heavenly Dao' means the great Dao that saves the world through the Daesoon Truth of Sangje, Supreme God of the Ninth Heaven. Divine Dao can be said to be 'the Dao by which man must complete his work according to the law and the will of God,' that is, 'the Dao by which God and man are united together by Sangje's heavenly order and teaching, which aims for humanity, righteousness, propriety, and wisdom.' When the world is in a state of calamity and crisis, the request for the saint's Dao can symbolized by the kings, Yao and Shun, in The Canonical Scripture (Jeon-gyeong). The saint's Dao saves the dying world and people's lives and is called 'saving lives by curing the world (濟生醫世)'. It can be regarded as a characteristic of Human Dao in Daesoon Thought, which is the human obligation to follow Sangje's order, the great Dao to save the world. The Dao of Sangsaeng is the true dharma that rectifies the world full of mutual conflict through the ethics of the Later World, which is to promote the betterment of others and to practice the human Dao that saves the world and rebuilds the Constant Dao. Thus, The concept of Dao in Daesoon Thought is Daesoon Truth which applies to and operates throughout all realms of Heaven, Earth, Humanity, and the Divine world. Dao in Daesoon Thought was influenced by the historical background in which it emerged and this can be seen in its ideological features. It embraces the traditional concept of Dao, which refers to the Chinese classics and represents the main schools of thought in East Asia: Confucianism, Buddhism, and Daoism. And it is unique in that it implies the will of Sangje as a religious object, a supreme being. It can be seen that Daesoon Thought has developed through the process of defining the concept of Dao by harmonizing both the universality and specificity of modern Korean religious thought.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.70-79
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• 2002

This study was conducted to determine correlations and combining abilities of leaf lengths, leaf widths, petiole lengths, number of branches, number of leaves, leaf areas, fresh weights, dry weights and number of flowers in F₁ crosses made with the partial seven-parent diallel cross in Viola tricolor. Leaf lengths and leaf widths showed highly positive correlation with petiole length and negative correlation with number of branches, number of leaves and number of flowers. There was positive correlation between the number of leaves and flowers as well as between leaf area and fresh weight. Mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the parameters. Variance component values of SCA were greater than those of GCA for all the parameters except leaf length, implying preponderance of non-additive gene actions for these characters. The lines C and G for leaf lengths and widths, the lines A and F for number of leaves, the lines A, B and G for leaf areas, and the lines B and F for number of flowers showed relatively high GCA effects. The crosses of A×B and B×D exhibited high SCA effects on increasing leaf lengths, leaf widths, number of leaves, fresh weights and number of flowers. And also the crosses of B×E and D×G exhibited high SCA effects on decreasing leaf lengths, leaf areas and fresh weights as well as increasing number of flowers. The broad sense heritabilities of most characters were high compared with the narrow sense one. Those of leaf length, leaf width, petiole length and number of leaves were high in both the broad and narrow sense heritabilities.

• Economic Analysis
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• v.27 no.3
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• pp.61-96
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• 2021

This study is to structurally examine the regional income disparity in Korea. It measures the regional income inducement by household consumption expenditure per unit income, and the regional interdependency of income using 2005 and 2015 Regional Input-Output Tables of 16 provincial regions of Korea. The results are as follows. Firstly, the income inducement by consumption expenditure per unit income decreased overall, mainly due to the decrease in the income inducement of other regions than due to that of their region. Secondly, in many regions, the inter-relational income dependency per unit income decreased also, this too, mainly due to the decrease in the income transfer to other region. And, the income inducement effects of consumption expenditure per unit income of Seoul and Gyeonggi, which occupy a large portion of the Korean economy, were lower than that of other regions, but took the largest portion of income inducements generated by other regions as well as by themselves and absorbed the income transfers from other regions the most. The higher income inducement and income absorption in Seoul and Gyeonggi by consumption expenditure of other regions were mainly because of the high share in service of their consumption structure, the progress in tertiarization of their industrial structure, and the high wage portion. These results also mean that viewed from the regional interdependency of income, the income of Seoul and that of Gyeonggi are highly dependent on the income of other regions. Especially, Gyeonggi which leads the overseas exports of high-tech based manufactured products, has other external factors that contribute to their high income inducement, whereas, Seoul which shows high income absorption using its inter-relations with other domestic regions based on the services, has an income-generating structure that is sensitive to other regions' economic situation. Amid overall declines in regional income inducements and in income transfers, and continuing concentrations into Seoul and Gyeonggi regions, to alleviate the regional disparity, the regional industry policies should, rather than benchmarking the policies of the two concentrated regions, enhance their own inter-regional relationships by strengthening the comparative advantage of their regionally specialized industry.

• Journal of Korea Water Resources Association
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• v.56 no.3
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• pp.195-210
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• 2023

Additional deposition and erosion in large rivers in South Korea have continued to occur toward morphological stabilization after massive dredging through the four major river restoration project, subsequently requiring precise bathymetry monitoring. Hyperspectral bathymetry method has increasingly been highlighted as an alternative way to estimate bathymetry with high spatial resolution in shallow depth for replacing classical intrusive direct measurement techniques. This study introduced the conventional Optimal Band Ratio Analysis (OBRA) of hyperspectral bathymetry method, and evaluated the performance in a domestic large river in normal turbid and flow condition. Maximum measurable depth was estimated by applying correlation coefficient and root mean square error (RMSE) produced during OBRA with cascadedly applying cut-off depth, where the consequent hyperspectral bathymetry map excluded the region over the derived maximum measurable depth. Also non-linearity was considered in building relation between optimal band and depth. We applied the method to the Nakdong and Hwang River confluence as a large river case and obtained the following features. First, the hyperspectal method showed acceptable performance in morphological mapping for shallow regions, where the maximum measurable depth was 2.5 m and 1.25 m in the Nakdong and Hwang river, respectively. Second, RMSE was more feasible to derive the maximum measurable depth rather than the conventional correlation coefficient whereby considering various scenario of excluding range of in situ depths for OBRA. Third, highly turbid region in Hwang River did not allow hyperspectral bathymetry mapping compared with the case of adjacent Nakdong River, where maximum measurable depth was down to half in Hwang River.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.491-501
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• 2022

Bentonite has been proposed as a buffer and backfill material for high-level radioactive waste repository. Under such repository environment conditions, bentonite is subjected to combined thermal, hydrological, mechanical, and chemical processes. This study evaluates the feasibility of applying X-ray CT technology on the characterization of bentonite under hydration conditions using a newly developed testing cell. The cylindrical cell is made of platic material, with a removable cap to place the sample, enabling to apply vertical pressure on the sample and to measure swelling pressure. The hydration test was carried out with a sample made of Gyeonju bentonite, with a dry density of 1.4 g/cm³, and a water content of 20%. The sample had a diameter of 27.5 mm and a height of 34 mm. During the test, water was injected at a constant pressure of 0.207 MPa, and lasted for 7 days. After one day of hydration, bentonite swelled and filled out the space inside the cell. Moreover, CT histograms showed how the hydration process induced an initial increase and later progressive decrease on the density of the sample. Detailed profiles of the mean CT value, CT standard deviation, and CT gradient provided more details on the hydration process of the sample and showed how the bottom and top regions exhibited a decrease on density while the middle region showed an increase, especially during the first two days of hydration. Later, the differences in CT values with respect to the initial state decreased, and were small at the end of testing. The formation and later reduction of cracks was also characterized through CT scanning.

• Journal of the Korean Geotechnical Society
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• v.23 no.9
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• pp.5-16
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• 2007

The simple linear elastic-perfectly plastic model with soil parameters $s_u,\;E_u$ and n of undrained condition is usually applied to predict the displacement of a constructed diaphragm wall(DW) on soft soils during excavation. However, the application of this soil model for finite element analysis could not interpret the continued increment of the lateral displacement of the DW for the large and deep excavation area both during the elapsed time without activity of excavation and after finishing excavation. To study the characteristic behaviors of soil behind the DW during the periods without excavation, a series of tests on soft Bangkok clay samples are simulated in the same manner as stress condition of soil elements happening behind diaphragm wall by triaxial tests. Three kinds of triaxial tests are carried out in this research: $K_0$ consolidated undrained compression($CK_0U_C$) and $K_0$ consolidated drained/undrained unloading compression with periodic decrement of horizontal pressure($CK_0DUC$ and $CK_0UUC$). The study shows that the shear strength of series $CK_0DUC$ tests is equal to the residual strength of $CK_0UC$ tests. The Young's modulus determined at each decrement step of the horizontal pressure of soil specimen on $CK_0DUC$ tests decreases with increase in the deviator stress. In addition, the slope of Critical State Line of both $CK_0UC$ and $CK_0DUC$ tests is equal. Moreover, the axial and radial strain rates of each decrement of horizontal pressure step of $CK_0DUC$ tests are established with the function of time, a slope of critical state line and a ratio of deviator and mean effective stress. This study shows that the results of the unloading compression triaxial tests can be used to predict the diaphragm wall deflection during excavation.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.281-289
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• 2022

Fusarium head blight is an important disease of small grains. It is mainly caused by members of the Fusarium graminearum species complex (FGSC). Barley and wheat growers spray fungicides, especially demethylation-inhibitor fungicides, to suppress the disease. The objective of this study was to examine the changes in the sensitivity of the FGSC population to the triazole fungicide, propiconazole. A total of 124 and 350 isolates of FGSC were obtained from barley and wheat in Jeolla Province during 2010-2016 and 2020-2021, respectively. The species identity and trichothecene chemotypes of the FGSC isolates were determined based on polymerase chain reaction assays targeting translation elongation factor 1-alpha and TRI12 genes, respectively. Sensitivity to propiconazole was determined based on the effective concentration that reduced 50% of the mycelial growth (EC₅₀) using the agar dilution method. Of all isolates, F. asiaticum with the nivalenol chemotype was the most common (83.9% in 2010-2016 and 96.0% in 2020-2021), followed by F. asiaticum with the 3-acetyl deoxynivalenol chemotype (12.1% in 2010-2016 and 2.9% in 2020-2021). The EC₅₀ values of the isolates collected in 2010-2016 and 2020-2021 ranged from 0.0180 to 11.0166 ㎍/mL and 1.3104 to 17.9587 ㎍/mL, respectively. The mean EC₅₀ value of the isolates increased from 3.8648 ㎍/mL in 2010-2016 to 5.9635 ㎍/mL in 2020-2021. The baseline resistance to propiconazole was determined to be 7 ㎍/mL, based on the EC₅₀ value of isolates collected in 2010-2016, and the ratio of resistant isolates increased from 9.7% in 2010-2016 to 28.6% in 2020-2021.

• Knowledge Management Research
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• v.24 no.1
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• pp.245-271
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• 2023

The change to the data economy requires a new analysis beyond ordinary research in the management field. Data matching refers to a technique or processing method that combines data sets collected from different samples with the same population. In this study, statistical matching was performed using random hotdeck and Mahalanobis distance functions using 2020 Survey of Korea Venture Firms and 2020 Korea Innovation Survey datas. Among the variables used for statistical matching simulation, the industry and the number of workers were set to be completely consistent, and region, business power, listed market, and sales were set as common variables. Simulation verification was confirmed by mean test and kernel density. As a result of the analysis, it was confirmed that statistical matching was appropriate because there was a difference in the average test, but a similar pattern was shown in the kernel density. This result attempted to expand the spectrum of the research method by experimenting with a data matching research methodology that has not been sufficiently attempted in the management field, and suggests implications in terms of data utilization and diversity.