• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.119-133
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• 2022

One of the most important current features of food related industry is the growth of food delivery service. Another notable food related culture is, with the advent of Youtube, the popularity of Mukbang, which refers to content that records eating. Based on these background, this study intended to focus on two things. First, we tried to see the impact of Youtube Mukbang and the sentiments of Mukbang comments on the number of related food deliveries. Next, we tried to set up the predictive modeling of chicken delivery order with machine learning method. We used Youtube Mukbang comments data as well as weather related data as main independent variables. The dependent variable used in this study is the number of delivery order of fried chicken. The period of data used in this study is from June 3, 2015 to September 30, 2019, and a total of 1,580 data were used. For the predictive modeling, we used machine learning methods such as linear regression, ridge, lasso, random forest, and gradient boost. We found that the sentiment of Youtube Mukbang and comments have impacts on the number of delivery orders. The prediction model with Mukban data we set up in this study had better performances than the existing models without Mukbang data. We also tried to suggest managerial implications to the food delivery service industry.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.236-244
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• 2023

The purpose of this study was to examine the economic feasibility of providing services according to the nationwide expansion of early warning services. The net present value method, one of the cost-benefit analysis methods, was applied to the analysis. As a benefit item that constituted the net present value, the damage reduction amount using crop insurance data and the willingness to pay for the use of early warning services were used. The cost items included system construction and maintenance costs, and text transmission costs. As a result of the analysis, it was found that the nationwide expansion of early warning services had economic feasibility, and its economic effect varied depending on the level of text message use (10 % to 40 %, 10 %p interval) of participating farmers. In the future, the economic effect of early warning services is expected to increase further due to the increase in the number of farmers participating in early warning services and the increase in crop damage caused by climate change. It is necessary to further enhance the economic effect of early warning services by actively utilizing information delivery means through apps or the web as well as text messages.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.528-534
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• 2009

Styan's Grasshopper Warblers (Locustella pleskei) are vulnerable species distributed in East-Asia only. Its known breeding sites in Korea are remote islets including Hongdo Islet, Chilbal Islet, Mara Islet, and Chuja Islets, and, therefore, the breeding biology of this species is still poorly known. This study was conducted on Mara Islet (N $33^{\circ}$ 06', E $126^{\circ}$ 16') from May to September 2008 to investigate the breeding status and breeding site characteristics of the grasshopper warblers. A total of 11 breeding pairs and their nests were found on trees and shrubs at artificially planted forests and hedges of Pinus thunbergii. The grasshopper warblers preferentially utilized the shrub trees for nesting places, and major nesting trees were Camellia japonica, Pittosporum tobira and Pinus thunbergii as nesting trees. Average heights of nesting trees and nests were $2.77{\pm}1.10m$ and $1.75{\pm}0.56m$, respectively. The grasshopper warblers selected lower shrubs and trees for nesting than randomly selected ones around them, probably to avoid strong and prevailed winds in flat and un vegetated environments on Mara Islet. The shape of nests was a round bowl-type, and measurements of nests were $11.9{\pm}0.5cm$ in exterior nest diameter, $11.1{\pm}1.1cm$ in height of exterior nest, $5.8{\pm}0.4cm$ in interior nest depth, and 6.0cm in interior nest diameter. It incubated eggs until the early August on Mara islet, and incubation periods of Mara Islet was possibly later than that of other areas. Furthermore, the clutch size in the study area was three, and they laid smaller number of eggs than normal clutch size (4~5 eggs) reported in other areas. Although we could not observe any nest predator on this species in the study area, selective cutting and pruning of trees will diminish dense shrub layer of forests. Therefore, it may affect the breeding of this threatened species which prefers dense shrubs of artificially planted forest of Pinus thunbergii. This study suggests that detailed and consistent further research on breeding biology and habitats of the grasshopper warblers are needed to conserve and manage of Pinus thunbergii forests on Mara Islet as an important breeding site of Styan's Grasshopper Warblers.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.52-60
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• 2006

This study investigated how wood properties (i.e., annual rings, sapwood, heartwood, and cracks) might affect preservative treatment in Japanese larch (Larix leptolepis) round-wood product. We specially focused on small-diameter (~10 cm diameter) wood that is commercially sold in market. Among 100 wood samples, the groups of sample with 13~16, 17~20 annual rings represented 33 and 27 in each frequency, while 2~3 and 4~5 mm annual ring width accounted for 72 and 68 in frequency. More than a half (54%) of wood samples contained a mix of heartwood and sapwood in its surface. The rest (46%) had only heartwood exposed in the wood surface. A wide range of checks were showed in the wood samples, but the highest frequency was observed in samples with 1~6 surface (1~14 mm in size) checks and 1~4 end-grain (8~14 mm in size) checks in each round-wood sample. Pressure treatment resulted in a wide range of penetration of ACQ (Alkaline Copper Quat) into the wood, showing $4.3{\pm}4.19mm$ penetration in the wood samples contained a mix of heartwood and sapwood in its surface. However preservative treatment was much less effective for the heartwood only wood samples, ranging average 1.3 mm with ACQ and 1.1 mm with CCA (Chromated Copper Arsenate). These penetration results shown in heartwood samples did not meet the penetration standard that is required for H3 by the Korean Forest Service in relation to wood preservation treatment. These low penetration results were not significantly improved even if we incised wood samples to improve treatment effect, showing only small increase of 0.7 mm with ACQ and 0.6 mm with CCA. When preservative treatment was tested with heartwood, penetration of preservatives decrease with increase of annual rings per a cross-section area (r=0.5345). We also found that the length and number of check had no effect on preservative treatment, showing r=0.1301 and r=0.1802, respectively.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.28-36
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• 2012

Forests are one of the basic assets nearest our daily lives that provide the foundation of life necessities, culture and even survival. These assets pervade local residents' lives as culture and the necessities of life, and they will be handed down to posterity. Therefore, this study was conducted to carry out a field survey on old trees, plant communities and forests in the southern coastal areas in Korea, where not many surveys were not conducted on the forest cultural assets, further examining a possibility that some of the trees should be designated as law-protected. As for the survey of plants, this study investigated 80 different spots of old trees, plant communities and forests, located in 11 cities and counties in Gyengnam Province and Jeonnam Province adjacent to the southern coast of Korea. To measure the health and actual maintenance conditions of old trees and plant communities objectively, the standard of judgment was established through the brain storming of experts. As a result of the field survey, out of all the old trees and plant communities that are not law-protected, this study selected old trees and plant communities that are in good health and likely to pass the standard of designating law-protected trees according to the Established Rule 574 of the Korea Forest Service Regulation. As for the plant community and old trees likely to be law-protected, this study judged that the torreya forest in Naneum Li, Namhae and old trees in 13 spots, in cluding so-called 'Couple Pine Tree' in Pyeongsa Li, Hadong, have a high possibility of being designated as a law-protected plant community and old trees. As for the species of old trees, there were 3 zelkova serrata trees, 3 celtis sinensis persoon trees, 2 pinus densiflora trees, 1 castanopsis cuspidata tree, 1 salix chaenomeloides tree and 1 machilus thunbergii tree found in the survey areas. Overall, this study judged that those old trees and plant communities require a national systematic maintenance by being designated as law-protected ones, and their values should be handed down to posterity as our forest cultural assets.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.87-96
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• 2005

This study was carried out to evaluate the shear bond strength and adhesive bond durability of structural glued laminated timber (glulam) manufactured with mixed species lumber of Korean red pine, Korean pine and Japanese larch, using resorcinol adhesive and water-based polymeric-isocyanate adhesive (WPI). Each board used as a glulam lamina was graded by visual inspection. The visual lumber grade of the all species was very low due to the large size and number of knots and the steep slope of grain. In view of the results, appropriate pruning, sawing and drying processes might be needed to produce high grade lamina lumber with small knot size and drying defect free. Shear bond strength of every tested glulam specimen ranged between 7.9 and $9.9N/mm^2$, and much higher than the Korean Standard (KS) for glulam shear bond strength, $7.1N/mm^2$. There was not much shear bond strength difference between wood/resorcinol and wood/WPI. The resorcinol adhesive bond durability exceeded KS requirements. However, delamination on the end-grain surfaces of WPI glulam submerged in both room temperature and boiling water severely occurred, and its durability did not meet KS requirements. Further investigations may be required, and special care should be taken, to ensure long service life of WPI glulam used for exterior application. Results of this study are expected to be useful for improvement of mechanical properties and structural performance of mixed species glulam.

• Journal of Climate Change Research
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• v.5 no.2
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• pp.127-137
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• 2014

The main purpose of this study is to estimate tradial growth response and to predict the potential spatial distribution of major tree species(Pinus densiflora, Quercus mongolica, Quercus spp., Castanea crenata and Larix kaempferi) in South Korea, considering climate and topographic factors. To estimate radial growth response, $5^{th}$ National Forest Inventory data, Topographic Wetness Index (TWI) and climatic data such as temperature and precipitation were used. Also, to predict the potential spatial distribution of major tree species, RCP 8.5 Scenario was applied. By our analysis, it was found that the rising temperature would have negative impacts on radial growth of Pinus densiflora, Castanea crenata and Larix kaempferi, and positive impacts on that of Quercus mongolica, Quercus spp.. Incremental precipitation would have positive effects on radial growth of Pinus densiflora and Quercus mongolica. When radial growth response considered by RCP 8.5 scenario, it was found that the radial growth of Pinus densiflora, Castanea crenata and Larix kaempferi would be more vulnerable than that of Quercus mongolica and Quercus spp. to temperature. According to the climate change scenario, Quercus spp. including Quercus mongolica would be expected to have greater abundance than its present status in South Korea. The result of this study would be helpful for understanding the impact of climatic factors on tree growth and for predicting the distribution of major tree species by climate change in South Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.42-51
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• 2020

This study was performed to support the 6th forest basic planning by Korea Forest Service as predicting the change of forestland area by the transition of land use type in the future over 35 years in South Korea. It is very important to analyze upcoming forestland area change for future forest planning because forestland plays a basic role to predict forest resources change for afforestation, production and management in the future. Therefore, the transitional interaction between land use types in future of South Korea was predicted in this study using econometrical models based on past trend data of land use type and related variables. The econometrical model based on maximum discounted profits theory for land use type determination was used to estimate total quantitative change by forestland, agricultural land and urban area at national scale using explanatory variables such as forestry value added, agricultural income and population during over 46 years. In result, it was analyzed that forestland area would decrease continuously at approximately 29,000 ha by 2027 while urban area increases in South Korea. However, it was predicted that the forestland area would be started to increase gradually at 170,000 ha by 2050 because urban area was reduced according to population decrement from 2032 in South Korea. We could find out that the increment of forestland would be attributed to social problems such as urban hollowing and localities extinction phenomenon by steep decrement of population from 2032. The decrement and increment of forestland by unbalanced population immigration to major cities and migration to localities might cause many social and economic problems against national sustainable development, so that future strategies and policies for forestland should be established considering such future change trends of land use type for balanced development and reasonable forestland use and conservation.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.635-653
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• 2012

Vascular plants of Oruem in region of Jeju-City were investigated 454 taxa totally; 116 families, 301 genera, 359 species, 3 subspecies, 78 varieties and 14 forms. In the studied Oruems in region of Jeju-City within altitude 800m, evergreen tree forests does not range and a lot of Pines thunbergii forest and Cryptomeria japonica and Chamaecyparis obtusa plantation forest were. The endemic species of Oruem in region of Jeju-City were 14 taxa such as Asarum maculatum, Hepatica insularis, Cardamine glechomifolia etc. The floristics degree categorized by the specific distribution of plant species were total 116 Taxa, that is, V grade species Magnolia kobus, Aconitum japonicum subsp. napiforme, Ligularia taquetii etc, 6 kinds be, IV grade species Rubus ribisoideus, Ligustrum salicinum, Carex macrandrolepis etc, 16 kinds be, III grade species Illicium anisatum, Hydrangea petiolaris, Rubus schizostylus etc, 37 kinds be, II grade species Pseudostellaria coreana, potentilla dickinsii, Euonymus pauciflorus etc, 6 kinds and I grade species Sphenomeris chinensis, Pteris multifida, Machilus thunbergii etc, be. 51 kinds were confirmed. Rare and Endemic Plant Species of Korea Forest Service were 11 taxa such as Asarum maculatum, Aconitum japonicum subsp. napiforme and Magnolia kobus etc. Naturalized plant were confirmed 31 taxons with Rumex acetosella, Hypochaeris radicata and Sisyrinchium atlanticum etc.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.1
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• pp.29-39
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• 2016

The purpose of this study was to suggest the improvement of the Mountainous Landscape Impact Review(MLIR) system for the conservation and eco-friendly use of mountain scenery. In order to understand the status of the MLIR system, a comparative analysis was conducted of the MLIR official guidelines and the 100 MLIR reports submitted to the Korea Forest Service from 2011 to 2013. In addition, an Importance-Performance Analysis(IPA) was conducted to take into account stakeholder opinions and to determine the first priorities to be improved upon in operation and functions of the MLIR system. The results of the IPA in evaluating the MLIR system showed that the components in the MLIR system that should be primarily improved are mountainous landscape resource inventory, objective and quantitative selection of viewpoints, and a checklist for examining the damage expected in mountainous lands. To Revitalize the Mountainous Landscape Impact Review system, the professional knowledge and experience of the stakeholders should be enhanced by education and training in the MLIR system over the short-term, while the effective functioning of the MLIR system should be reinforced by differentiation and connectivity of the MLIR system with similar institutions, and by emphasizing the uniqueness and properties of mountainous landscapes over the long-term.