• Journal of Nutrition and Health
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• v.56 no.3
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• pp.300-314
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• 2023

Purpose: This study sought to predict the reasons for skipping breakfast by adolescents aged 13-18 years using the 7^th Korea National Health and Nutrition Examination Survey (KNHANES). Methods: The participants included 1,024 adolescents. The data were analyzed using a complex-sample t-test, the Rao Scott χ²-test, and the classification and regression tree (CART) algorithm for decision tree analysis with SPSS v. 27.0. The participants were divided into two groups, one regularly eating breakfast and the other skipping it. Results: A total of 579 and 445 study participants were found to be breakfast consumers and breakfast skippers respectively. Breakfast consumers were significantly younger than those who skipped breakfast. In addition, breakfast consumers had a significantly higher frequency of eating dinner, had been taught about nutrition, and had a lower frequency of eating out. The breakfast skippers did so to lose weight. Children who skipped breakfast consumed less energy, carbohydrates, proteins, fats, fiber, cholesterol, vitamin C, vitamin A, calcium, vitamin B1, vitamin B2, phosphorus, sodium, iron, potassium, and niacin than those who consumed breakfast. The best predictor of skipping breakfast was identifying adolescents who sought to control their weight by not eating meals. Other participants who had low and middle-low household incomes, ate dinner 3-4 times a week, were more than 14.5 years old, and ate out once a day showed a higher frequency of skipping breakfast. Conclusion: Based on these results, nutrition education targeted at losing weight correctly and emphasizing the importance of breakfast, especially for adolescents, is required. Moreover, nutrition educators should consider designing and implementing specific action plans to encourage adolescents to improve their breakfast-eating practices by also eating dinner regularly and reducing eating out.

• Journal of the Korean Data and Information Science Society
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• v.23 no.5
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• pp.949-959
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• 2012

This article is to find the right size of decision trees that performs better for boosting algorithm. First we defined the tree size D as the depth of a decision tree. Then we compared the performance of boosting algorithm with different tree sizes in the experiment. Although it is an usual practice to set the tree size in boosting algorithm to be small, we figured out that the choice of D has a significant influence on the performance of boosting algorithm. Furthermore, we found out that the tree size D need to be sufficiently large for some dataset. The experiment result shows that there exists an optimal D for each dataset and choosing the right size D is important in improving the performance of boosting. We also tried to find the model for estimating the right size D suitable for boosting algorithm, using variables that can explain the nature of a given dataset. The suggested model reveals that the optimal tree size D for a given dataset can be estimated by the error rate of stump tree, the number of classes, the depth of a single tree, and the gini impurity.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.2 s.121
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• pp.71-80
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• 2007

Korea began preserving and managing natural monuments in 1933 under Japanese Colonization, but North Korea and South Korea were forced to establish separate natural monument management policies because of the division after the Korean Independence. The purpose of this study is to compare and analyze the natural monument management policies of both south and North Korea between 1933 and 2005 to introduce new policies for Korea unification. The following are the results: First, South Korea manages every type of cultural asset, including natural monuments, through the 'Cultural Heritage Protection Act,' whereas North Korea managing its cultural assets through the 'Cultural Relics Protection Act' and the 'Landmark/Natural Monument Protection Act.' Second, South Korea preserves and utilizes natural monuments for the purpose of promoting the cultural experience of Korean people and contributing to the development of world culture, whereas North Korea uses its natural monuments to promote the superiority of socialism and protect its ruling power. Third, North and South Korea have similar classification systems for animals, plants, and geology, but North Korea classifies geography as one of its natural monuments. Unlike South Korea, North Korea also designates imported animals and plants not only for the preservation and research of genetic resources, but also for their value as economic resources. Fourth, North Korea authorizes the Cabinet to designate and cancel natural monuments, whereas South Korea designates and cancels natural monuments by the Cultural Heritage Administration through the deliberation of a Cultural Heritage Committee. Both Koreas' central administrations establish policies and their local governments carry them out, while their management systems are quite different. In conclusion, it is important to establish specified laws for the conservation of natural heritages and clarified standards of designation in order to improve the preservation and management system and to sustain the diversity of natural preservation. Moreover it is also necessary to discover resources in various fields, designate protection zones, and preserve imported trees. By doing so, we shall improve South Korea's natural monument management policies and ultimately enhance national homogeneity in preparation for the reunification of the Koreas in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.305-313
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• 2019

Recently, spatial information is being constructed actively based on the images obtained by drones. Because occlusion areas occur due to buildings as well as many obstacles, such as trees, pedestrians, and banners in the urban areas, an efficient way to resolve the problem is necessary. Instead of the traditional way, which replaces the occlusion area with other images obtained at different positions, various models based on deep learning were examined and compared. A comparison of a type of feature descriptor, HOG, to the machine learning-based SVM, deep learning-based DNN, CNN, and RNN showed that the CNN is used broadly to detect and classify objects. Until now, many studies have focused on the development and application of models so that it is impossible to select an optimal model. On the other hand, the upgrade of a deep learning-based detection and classification technique is expected because many researchers have attempted to upgrade the accuracy of the model as well as reduce the computation time. In that case, the procedures for generating spatial information will be changed to detect the occlusion area and replace it with simulated images automatically, and the efficiency of time, cost, and workforce will also be improved.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.133-145
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• 2010

This study analyzed the characteristics of sediment produce by landslide triggered by rainfall. One-dimensional unsaturated groundwater model and infinite slope stability analysis were used to estimate the behavior of soil moisture and slope stability according to rainfall, respectively. Slope stability analysis was performed considering on soil depth and characteristics of trees. As the results considering on recovery of the failed slopes, much amount of sediment was produced in 1963, 1970, and 2002. As the results of verification of simulation results using Landsat 5 TM images, we can find differences of landslide location between the results from model and satellite images. These differences can be caused by uncertainties of the rough parameters in the model. However, in the case that Obong-dam basin was divided into two subbasin, Wangsan-chun and Doma-chun basin, the results of each subbasin show errors around 20%. And only 4% of error occurred in the case of comparing landslide area on the entire Obong-dam basin. These errors seem insignificant considering on the errors which can be caused from the analyses in this study such as estimation of sediment produce, soil cover classification, and estimation of landslide area.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.708-721
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• 2019

This study was conducted to understand the plant community structure characteristics of warm-temperate forest in Geoje Island. Survey sites were set up on ridges, valleys, and slopes where evergreen broad-leaved trees predominated or distributed in canopy, sub-canopy, or shrub layers at Chunjangsan(Mt.). Thirty-one sites were located in the areas, such as vegetation community, ridges, valleys, and slopes, to observe vegetation structure and location changes. The community classification with TWINSPAN identified six groups: Neolitsea sericea-Platycarya strobilacea, N. sericea-Styrax japonicus, N. sericea-Euonymus oxyphyllus, Pinus thunbergii-N. sericea, N. sericea-Quercus serrata, and Q. variabilis-P. strobilacea. Considering the results of previous studies that reported that the successional pattern of the warm temperate forests progressed from deciduous to evergreen forests, the regions predominated by deciduous communities such as P. thunbergii, Q. serrata, P. strobilacea, Zelkova serrata, and Q. variabilis, is likely to transform into the evergreen forest predominated by N. sericea. The relationship between the impact of the environmental factors and the vegetation distribution showed that slope, Na +, K +, electrical conductivity, and clay among physical properties had direct or indirect effects on vegetation distribution.

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.26-35
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• 1989

Studies were carried out to compare from the viewpoint of peroxidase isoenzyme patterns by ages, locations and organs. In addition, the relationships among six cultivars peroxidase isoenzyme patterns were compared and the relationships between cultivars and their hybrids were examined. The results are summarized as follows. 1. The zymogram was not affected by the ages of 'Fuji' cultivar. 2. There was no locational difference in zymogram among Suwon, Taejon and Yesan in 'Fuji' and 'Tsugaru' cultivars. 3. Significant difference in isozyme patterns was found between stems and leaves in 'Fuji' and 'Tsugaru' cultivars. 4. There were some differences in zymogram among 'Ralls Genet', 'Fuji', 'Jonathan', 'Starking', 'Golden Delicous' and 'Tsugaru' cultivars. 5. Classification was made by the peroxidase isozyme development between cultivars and their hybrids. 1) The type showed both parent's isozyme pattern. 2) The type showed a loss of a part of parent's isozyme bands. 3) The type developed new isozymes which were not detected in parent plants.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.360-368
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• 1991

Utilizing chi-square test statistics, inter-species association and covariation were analyzed for the 37 woody plant species in a deciduous forest dominated by Quercus mongolica and Q. variabilis. within 50 temporarily established $20m{\times}20m$ square quadrats, the association for each pair of species was presented based on the presence-absence parameters. Acer palmatum had significant positive association with Acer mono and Kalopanax pictus, but negative association with Pinus densiflora. Other positively associated species pairs were Prunus sargentii-Macckia amurensis, Quercus serrata-Kalopanax pictus, Symplocos chinensis var. pilosa-Euonymus oxyphyllus, and Ulmus davidiana var. japonica-Lindera obtusiloba. The covariation far each pair of species was evaluated based on the quantitative measures, density and basal area. Overall results showed that the association and covariation values among species generally agreed with each other. Because covariation was calculated by density and basal area of the tallied species in the sample plots, the number of species pairs of covariation tended to be greater than those of association. Especially, Pinus densiflora, considered to be pioneer species in the successional stage, had negative covariation with most of climax species. These ecological information could be applied to silvicultural practices, such as ecosystem classification, establishment of mixed hardwood forest, and tending operations for marking crop trees and desirable species.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.2
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• pp.195-214
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• 2009

The Mangi yoram("萬機要覽"), a guidebook of state affairs, was published by royal command in the late Joseon period. Its chapters on financial affairs(財用篇) are particularly remarkable, as they explain on all aspects of the national finance of the late Joseon period in a clear manner. The financial part of the Mangi yoram includes metallic mineral resources, such as the location of gold, silver, copper, lead deposits and the prosperity and decline of the mines, and the various uses of each of the minerals. These are still regarded as valuable resources. Its contents on agricultural geography comprise not only the total yearly output of grains, paddyfields and dryfields, their taxation and standards of taxation, but also ginseng which was famous in the outside world in the pre-modern era. The book also clearly explains distribution of agricultural dikes for irrigation and their functions. The book also contains information on forestry geography, e.g. the varieties of pine trees and their distribution and mountain containment policies. Contents related to commercial geography consist of material on different types of markets such as the yukuijeon(六矣廛), sijeon(市廛), peongsisuh(平市署), nanjeon(亂廛), and the distribution, size and prosperity and decline of the border markets of the northern frontier such as the hoeryungkaesi(會寧開市) and geongwonkaesi(慶源開市). Contents related to transport geography are the distribution and functions of government granaries etc. Obviously, this book contains detailed information on various aspects of Korean geography. If we try to understand the contents of this book from the framework of modern geographical classification schemes, the geographic information contained in the book assumes even greater significance. In sum one may conclude that this book, which the king kept by his side, contained useful geography related knowledge and necessary information, and was directly relevant to the administration of the country. It exerted immense influence on the contemporary intellectual world of Joseon Korea, and was regarded as an invaluable resource.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.929-933
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• 2010

According to the IPCC guideline (2006), uncertainty assessment is very important in terms of the greenhouse gas inventory. Therefore, the purpose of this study is to estimate the basic wood density (BWD) and its uncertainty for Pinus densiflora in Korea. In this study, Pinus densiflora forests were divided into two ecotypes which were Gangwon and Jungbu regions. A total of 33 representative sampling plots was selected to collect sample trees after considering the tree ages and DBH distributions. The BWD showed statistically no difference between age classes based on IPCC's classification. While, it showed statistically difference(pvalue=0.0017) between eco-types. The BWD and uncertainty was 0.396(g/$cm^3$) and 12.9(%) for Pinus densiflora in Gangwon, while it was 0.470(g/$cm^3$) and 3.8(%) for Pinus densiflora in Jungbu. The values of the BWD uncertainty for Pinus densiflora were more precised than the values given by the IPCC guideline.