• Journal of Life Science
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• v.28 no.11
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• pp.1262-1267
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• 2018

The patchiness of local environments within a habitat is assumed to be a primary factor affecting the spatial patterns of plants. In this study, a randomization procedure was developed to test the null hypothesis that only spatial association with patches determines the spatial patterns of plants. Oplismenus undulatifolius (Ard.) P. Beauv. var. undulatifolius is an herbaceous plant and a member of the genus Oplismenus in the family Poaceae. Oplismenus hirtellus subsp. undulatifolius occurs in temperate, subtropical, and tropical areas of the world. The spatial pattern of O. undulatifolius var. undulatifolius was analyzed using dispersion indices in different sizes of plots according to several patchiness indexes, population uniformity, or aggregation. Population densities (D) at Mt. Hanwoo varied from 0.453 to 4.375, with a mean of 2.387. The small and mid-sized plots ($2m{\times}2m$, $2m{\times}4m$, $4m{\times}4m$, $4m{\times}8m$, and $8m{\times}8m$) of O. undulatifolius var. undulatifolius were aggregated in the forest community. However, O. undulatifolius var. undulatifolius was uniformly distributed in three large plots ($8m{\times}16m$, $16m{\times}16m$, and $16m{\times}32m$). The greatest mean crowding ($M^*$) and patchiness index (PAI) showed positive values. Aggregation is mainly caused by environmental factors. Many plants on Mt. Hanwoo are being disturbed by climbers, which is preventing these plants from inhabiting their realized niches on Mt. Hanwoo.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.15 no.1
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• pp.35-39
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• 2019

Oculo-cerebro-renal syndrome, known as Lowe syndrome, is an X-linked gene disorder characterized by congenital cataracts, brain abnormalities and renal dysfunction. Tooth crowding, taurodontism, delayed eruption in the permanent dentition and over-retained primary teeth with ectopic eruption of the permanent teeth have been reported as dental findings. Because of the high incidence of poor cooperation, patients with Lowe syndrome have difficulties in maintaining good oral hygiene, which may require dental treatment. We present a case of dental treatment for the uncooperative child with Lowe syndrome under general anesthesia. A 4-year-old, 11.2 kg boy with Lowe syndrome visited Seoul National University Dental Hospital for gingival swelling. The patient had multiple caries requiring dental treatment. Because of his past history of malignant hyperthermia during inhalation induction, anesthesia was induced and maintained with total intravenous anesthesia (TIVA) after medical consultation. Dental restorative treatments were successfully performed and no complications were observed during and after the procedure. Safe and effective dental management of the patients with Lowe syndrome could be performed with the help of general anesthesia and careful monitoring.

• Journal of Technology Innovation
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• v.27 no.1
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• pp.1-43
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• 2019

The significance of SMEs (small and medium-sized enterprises) is gradually highlighted as we have entered the age of "New Normal." The South Korean government support these enterprises to boost economic growth and create more jobs. It also releases numerous policies such as national R&D projects and expanding tax incentive services particularly aiming at promoting dramatic investment in R&D and technological innovation. There is a sharp contrast regarding the efficiency of direct or indirect supports for encouraging R&D investment launched by SMEs depending on researchers. However, there has been little attempt to explore the optimal combination of two policy tools. Amid promoting affiliated governmental departments in charge of SMEs policies and constantly growing R&D investment, it is an appropriate time to discuss the medium and long-term direction for the optimal policy mix of direct and indirect supports. In this study, the author obtained 32 relevant studies published earlier in the domestic journals, explored literatures more systematically, and further conducted a meta-analysis. It is dedicated to summarizing relevant controversies and organizes them empirically beyond merely verifying whether policy support stimulates private R&D investment by SMEs. The meta-analysis showed that it would be effective to support as tax for large enterprises, while subsidiary support for SMEs. However, indirect support needs to be progressively increased as direct support primarily accounts for the entire R&D support for South Korean SMEs.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.274-282
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• 2022

In order to secure pedestrians' right to walk, we have up-cycled second hand mobile phones to overcome limitations of the existing survey methods, analysis methods, and diagnosis to reduce pedestrian traffic accidents. Second hand mobile phones were up-cycled to produce mobile CCTVs and installed in areas where pedestrian deaths rate is high to secure image data sets for the period of more than 24 hours. It was analyzed by applying image visualization technology and clouding reporting technology, and more precise and accurate results were derived through modeling based on artificial intelligence learning and GIS-based diagnostic guidance. As a result, it was possible to analyze the risk factors and number of pedestrian safety, and even factors that were not known in the existing method could be derived. In addition, the traffic accident risk index was derived by converting data into one year to verify whether second hand mobile phone up-cycling mobile CCTV will be an objective tool for finding pedestrian risk factors. Up-cycling mobile CCTV of second hand mobile phones newly applied through research can be used as a new tool to find pedestrian risk factors, and it can be used as a service to protect the safety of the traffic vulnerable other than pedestrians.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.183-187
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• 2021

Appropriate pruning is very important for southern highbush blueberries cultivated in a heated plastic house to control their severe crowding within the bush canopy after harvest. Pruning treatments at different times were evaluated to find out an appropriate pruning time to southern highbush 'Scintilla' cultivation with heating. Seven-year-old (2018) bushes, grown in 180-L containers, were summer-pruned on May 20 (35-39 days after harvest) and June 20, or dormant-pruned on December 20 (5 days before flowering), consecutively in both 2018 and 2019 removing 30% of the total woods. May pruning activated occurrence of shoots the following years, increasing number of shoot by 17 to 49% and total shoot length by 18 to 32% compared with those of the dormant pruning. Fruit characteristic was not significantly affected by different pruning times the previous year. The first year pruning treatment did not influence the yield the following year, but the second year consecutive May pruning significantly increased yield per bush by 7% compared with the dormant pruning. The results indicated that summer pruning in May could be favorable to promote shoot growth and to maintain stable yield.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.791-802
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• 2021

In Korea, the cities continue to deteriorate, while the vacant houses in the small local towns emerge as a serious social problem. Despite the vacant houses emerge as a serious social problem in the small local towns as well as in the large cities, the basic researches into them are yet to be conducted on a full scale. Thus, in order to know about the spatial distribution of the vacant houses, this study conducted the square analysis and the kernel density analysis. As a result, it was confirmed that the vacant houses in Okcheon-gun had certain crowding forms and characteristics at the level of statistical significance. Next, in order to examine the distribution of the vacant houses in terms of the accessibility to the living SOC facilities, the GIS network analysis was performed, focusing on the major facilities and road networks. As a result, it was found that the better the accessibility to the living SOC facilities such as medical and well-being was, the ratio of the vacant houses was lower. In contrast, it was found that the accessibility to the obligatory facilities such as public administration and educational facilities did not have any important effects on the distribution of the vacant houses. All in all, through this study, the spatial distribution of the vacant houses in the small local town and their accessibility to the major SOC facilities could be analyzed.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.96-103
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• 2023

Generally, human stampedes and crowd collapses occur when people press against each other, causing falls that may result in death or injury. Particularly, crowd accidents have become increasingly common since the 1990s, with an average of 380 deaths annually. For instance, in Korea, a stampede occurred during the Itaewon Halloween festival on October 29, 2022, when several people crowded onto a narrow, downhill road, which was 45 meters long and between 3.2 and 4 meters wide. Precisely, this stampede was primarily due to the excessive number of people relative to the road size. Essentially, stampedes can occur anywhere and at any time, not just at events, but also in other places where large crowds gather. More specifically, the likelihood of accidents increases when the crowd density exceeds a turbulence threshold of 5-6 /m². Meanwhile, festivals and events, which have become more frequent and are promoted through social media, garner people from near and far to a specific location. Besides, as cities grow, the number of people gathering in one place increases. While stampedes are rare, their impact is significant, and the uncertainty associated with them is high. Currently, there is no scientific system to analyze the risk of stampedes due to crowd concentration. Consequently, to prevent such accidents, it is essential to prepare for crowd disasters that reflect social changes and regional characteristics. Hence, this study proposes using digital topographic maps and crowd-density risk simulations to develop a 3D model of the region. Specifically, the crowd density simulation allows for an analysis of the density of people walking along specific paths, which enables the prediction of danger areas and the risk of crowding. By using the simulation method in this study, it is anticipated that safety measures can be rationally established for specific situations, such as local festivals, and preparations may be made for crowd accidents in downtown areas.

• Korean Journal of Social Welfare Studies
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• v.41 no.1
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• pp.145-173
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• 2010

The purpose of this study is to verify that several theories explaining the determinants of welfare expenditure is applied to the family policy expenditure and to find out if there' re unique determinants of the family policy expenditure. We analyzed the data (OECD 14 countries for 1980~2005) by pooled time series analysis. As for industrialization theory, female labor force participation rate has positive effect on family policy expenditure while population under 15-year children has negative effect, which refers to the demand of family policies is that of female workers, not children's. Power resource theory is applied to the determinants of family policy expenditure as those of welfare expenditure. Women's political & economic empowerment has partly positive effects on family policy expenditure, which is the evidence of the effectiveness of feminist theory. In the institutional theory, we verified the effect of policy legacy but couldn't find out the crowding-out effect. The theoretical implication of this study is the empirical verification of the theories explaining the determinants of welfare expenditure being applied to the family policy expenditure. We also suggested the political and institutional foundation to effectively respond to the new social risks in spite of budget constraints, which can be a policy implication.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.115-126
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• 2000

Dental arch expansion is one of the method used to solve the dental crowding problem by non-extraction. Many formulae using tooth size have been suggested to predict ideal inter-premolar and inter-molar width. The purpose of this study was to evaluate the adequacy of some upper dental arch width prediction methods, namely Pont's method, Schmuth's method and Cha's method. The sample consisted of the casts of 119 Korean young adults who had no muscular abnormality, no skeletal discrepancy, and Angle's Class I molar relationships. Measurements were obtained directly from plaster casts; they Included mesiodistal crown diameters of the four maxillary incisors, as well as maxillary inter-first-premolar and inter-first-molar arch widths as specified by Pont. The correlation coefficients between the sum of incisors(SI) and upper dental arch width were calculated. The differences between predicted width and actual width were classified as overestimated, properestimated, and underestimated. The data obtained from each group were analyzed for statistical differences. The results were as follows : 1. Upper dental arch width indices were calculated from SI in normal occlusion (81.96 : premolar index, 62.55 : molar index). 2. Low correlations between SI and arch width were noted in normal occlusion (0.50 in the inter-premolar width, 0.39 in the inter-molar width). 3. Pont's formula and Schmuth's formula tended to overestimate the inter-premolar width. A more even distribution of estimates was noted in Cha's fomula. 4. Cases within $\pm$1 mm range of observed inter-premolar width were $45\%$ in the Cha's formula, $40\%$ in the Pont's formula, and $39\%$ in the Schmuth's formula. 5. All formulae had a tendency to underestimate the inter-molar width, but Cha's formula had better predictability than others. 6. Cases within $\pm$1 mm range of observed inter-molar width were $40\%$ in the Cha's formula, $29\%$ in the Pont's formula, and $13\%$ of Schmuth's formula. The data presented in this study does not support the clinical usefulness of ideal arch width prediction methods using the mesiodistal width of maxillary incisors.

• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.63-72
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• 2003

Over the Past decades, the number of Patients seeking orthodontic treatment has increased markedly with socioeconomic development and change of recognition on appearance. The purpose of this study was to provide an epidemiologic data base related to the orthodontic treatment need. We could take an adequate information regarding the characteristics of orthodontic patients, and the changing trends about treatment mordality. Distrubution and treands were Investigated in 676 patients who had been examined and diagnosed at Department of orthodontics, Dental Hospital, Seoul National University from January to June in 1992 and 2002. 1. Sex distribution of patients changed from 1:2.1 to 1:1.5 (male female). 2. In 2002, are distribution had shown $7\~12$ year-old group being the largest$(32.0\%)$ and percentage of $19\~24,\;13\~18,\;over\;25,\;4\~6,\;0\~3$ year-old group were $24.0\%,\;21.6\%,\;14.2\%,\;5.8\%,\;2.4\%$ respctively. Compared with data in 1992, the number of adult patients highly increased. 3. With regard to Angle classification, each percentage of Class I, Class II div 1, Class II div 2, and Class III malocclusion were $25.0\%,\;20.9\%,\;3.4\%,\;and\;48.1\%$ respectively in 2002. 4. Geographic distribution showed that most of the patients visited $(37.0\%)$ lived in northeast of Seoul in 2002. 5. Mandibular prognathism showed the highest percentage in chief complaints. The percentages of crowding and facial asymmetry were $14.2\%\;and\;11.8\%$ in 2002. Patients with facial asymmetry increased significantly. 6. Percentages of patients treated with fixed appliance and orthognathic surgery were $38.0\%\;and\;25.0\%$ in 2002. Patients needed to observe the growth pattern comprised $13.0\%$ with increasing trends. The use of chin cap reduced and the percentage of ortognathic surgery and growth observation increased significantly.