• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.5-8
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• 1977

Monthly and partial variation of moisture contents of Quercus glauca Thunb. and Pinus banksiana Lamb. are investigated. There are monthly and partial insignificant variations of air dried moisture contents in both woods. But in moisture contents in green, former showed minimum rate at middle part, maximum at upper one, seasonally minimum in spring and maximum in autumn, latter showed minimum at lower part, maximum at upper one, seasonally minimum in winter and maximum in summer.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.593-598
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• 2014

In this study, we developed the carbon emission factors for 4 major species of warm-temperate region in Korea, and tried to provide their carbon emissions and removals estimates using these carbon emission factors. We selected Castanopsis cuspidata, Camellia japonica, Quercus acuta and Quercus glauca as target species and derived their carbon emission factors. The basic wood density that serve as one of the carbon emission factors were 0.583 for Castanopsis cuspidata, 0.657 for Camellia japonica, 0.833 for Quercus acuta and 0.763 for Quercus glauca and their uncertainties ranged from 5.3 to 17.9%. Biomass expansion factors were calculated as well: 1.386 for Castanopsis cuspidata, 2.621 for Camellia japonica, 1.701 for Quercus acuta and 2.123 for Quercus glauca and associated uncertainties varied from 14.7 to 30.5%. Lastly root-shoot ratios for each species were also determined: 0.454 for Castanopsis cuspidata, 0.356 for Camellia japonica, 0.191 for Quercus acuta and 0.299 for Quercus glauca with the uncertainties lying within a range from 19.8 to 35.7%. These three carbon emission factors including basic wood density had the uncertainties of less than 40% recommended by FAO. Therefore the application of country-specific emission factors seemed to provide quite accurate estimates of carbon emissions and removals. The estimation of the carbon stored in the 4 species were also conducted which amounted to $186.10tCO_2/ha$ for Castanopsis cuspidata, $280.63tCO_2/ha$ for Camellia japonica, $344.04tCO_2/ha$ for Quercus acuta and $278.91tCO_2/ha$ for Quercus glauca and their annual carbon removals were $6.65tCO_2/ha/yr$, $6.25tCO_2/ha/yr$, $11.70tCO_2/ha/yr$ and $12.29tCO_2/ha/yr$, respectively. This systematic assessment of forest resources can be a reliable source of information for managing evergreen broadleaved forest in warm temperate regions and thus serve as useful data for effective decision-making to address vegetation zone shifts due to climate change.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.393-404
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• 2023

The Natural Monument Forest (NMF) is a form of natural and cultural heritage that has symbolized the harmony between nature and culture in Korea for a long time. Recently, the NMF has deteriorated due to industrialization and reckless city expansion. Given this situation, it is necessary to preserve and manage the ecosystem of the NMF through preferential research regarding the forest community structure. Accordingly, this study sought to identify the community structure by analyzing the vegetation classification, stratum structure,and species diversity using vegetation data collected from the Forest of Japanese Torreyas in Pyeongdae-ri, Jeju and the Subtropical Forest of Nabeup-ri, Jeju. The results classified the forest vegetation as a Litsea japonica community group divided into two communities: a Torreya nuciferacommunity and a Quercus glauca community. The T. nuciferacommunity was subdivided into the Idesia polycarpa group and Dryopteris erythrosora group, while the Q. glauca community was subdivided into the Mercurialis leiocarpa group and Arachniodes aristata group. The T. nucifera species showed the highest level of importance in vegetation units 1 (Litsea japonicacommunity group-Torreya nucifera community-Idesia polycarpa group) and 2 (Litsea japonica community group-Torreya nucifera community-Dryopteris erythrosora group), whereas Q. glauca showed the highest level of importance in vegetation units 3 (Litsea japonica community group-Quercus glauca community-Mercurialis leiocarpa group) and 4 (Litsea japonica community group-Quercus glauca community-Arachniodes aristata group). In terms of the species diversity, vegetation units 1, 2, 3, and 4 had 2.866, 2.716, 2.222, and 2.326 species, respectively. These findings suggest that it is necessary to prepare a differentiated management plan for each vegetation unit.

• The Korean Journal of Financial Management
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• v.27 no.2
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• pp.145-167
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• 2010

We investigate the dynamic relationship between stock returns and investors' behavior. For the putpose of the paper, daily KOSPI returns are decomposed into two parts: overnight returns and daytime returns. Overnight return is measured by the closing price of the previous day and the opening price of the current day. And daytime return is measured by the opening and closing prices of the current day. Qvernight returns are assumed to reflect global economic information, and daytime returns, domestic or local information. Major results are as follows: Foreign investors' behavior has an effect on the overnight returns more than the daytime returns. Individual investors' behavior, however, has little effect on the overnight returns, but not the daytime returns. Consequently, forecast error variance decomposition shows that the variance explanation power of foreign investors is higher in overnight returns rather than in the daytime returns. And the variance explanation power of individual investors is higher in daytime returns rather than in overnight returns. It implies that foreign investors employ dynamic hedging strategies and give more weight to global economic information rather than to domestic information. We conclude that investment behavior of foreign investors and domestic individuals is based on different economic information. This paper's findings are consistent with the economic situation that the Korean capital markets have faced since the global financial crisis of August 2008.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.234-240
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• 2013

Increasing global $CO_2$ concentration and temperature is leading to the phenomenon of global warming and impacting the growth of plants. In order to determine the effects of global warming on the woody plants of Korea, five woody species, Pinus densiflora (Korea's dominant species), Ginkgo biloba (a commonly used street tree), Quercus glauca (dominant species in sub-tropical forests), Quercus gilva and Abeliophylum distichum (both endangered species), were grown at control (ambient $CO_2$+ambient temperature) and treatment (elevated $CO_2$+elevated temperature) conditions in a glasshouse, and were monitored for their ecological response. Shoot lengths and number of leaves were measured once a month from April to October in 2010, and were again measured in November 2011. Shoot lengths of P. densiflora, G. biloba and Q. glauca were not significantly affected by elevated $CO_2$ and temperature conditions. However. those of Q. gilva and A. distichum were both higher for plants grown under treatment than for those grown under control. The number of leaves of five woody species was not significantly affected by elevated $CO_2$ and temperature. These results indicate that P. densiflora, G. biloba and Q. glauca react more favorably than Q. gilva and A. distichum (each of which are designated as endangered plants) under global warming situations.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.295-310
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• 2017

This study investigated the growth of five phytopathogenic fungi including Colletotrichum gloeosporioides, Diaporthe citri, Phytophthora capsici and others according to different concentrations of water extract in order to provide reference data for developing environment-friendly agricultural materials using five native Fagaceae species including Quercus acuta, Quercus salicina, Quercus glauca, Quercus gilva and Castanopsis cuspidata var. sieboldii. As the concentration of aqueous extracts of Fagaceae increased according to donor plants, the mycelial growth of phytopathogens showed a decreasing tendency. Differences were found in the degree of inhibition according to types of donor plants and pathogenic fungi. Diaporthe citri, Phytophthora capsici, Pythium graminicola on the water extract of Castanopsis cuspidata var. sieboldii inhibited mycelial growth by 84% in 25% of the treatment group and by 87% in more than half of the treatment group. The water extract of Quercus acuta was found to have no inhibitory effect against the mycelial growth of Diaporthe citri. The aqueous extracts of Quercus salicina, Quercus glauca and Quercus gilva insignificantly inhibited mycelial growth by approximately 15%. The total phenolic content of receptor plants exhibiting antifungal activity was highest in Castanopsis cuspidata var. sieboldii with a content of 22.32 mg/g phenols, followed by Quercus salicina with 8.32 mg/g, Quercus glauca with 6.83 mg/g, Quercus gilva with 5.95 mg/g, and Quercus acuta with 5.24 mg/g. The aqueous extracts of Castanopsis cuspidata var. sieboldii among the five Five Fagaceae Plants of were the most effective antifungal activity.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.484-492
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• 2019

The aim of the present study was to compare the cold tolerance of seven different types of trees growing in southern Korea to select evergreen broad-leaved trees that can be used as street trees in large land areas experiencing climate change. The trees compared were the thorn tree, Cinnamomum camphora, Camellia japonica, Machilus thunbergii, Dendropanax morbifera, Daphniphyllum macropodum Miq., Quercus glauca Thunb., and Raphiolepis indica. When the trees were subjected to low temperature treatment, their electrolyte elution volume values appeared to increase with the decreases in the treatment temperature. The analysis of the cold tolerance of each type of tree was based on the estimated temperatures in the following order: C. japonica (-11.586℃) > R. indica (-9.348℃) > Q. glauca (-8.719℃) > M. thunbergii (-8.090℃) > D. macropodum (-7.409℃) > D. morbifera (-7.085℃) > C. camphora (-6.995℃). The relative cold tolerance difference found in the seven tree species was more than 5℃, as evaluated previously. In the Lauraceae family, the difference in cold tolerance was more than 2℃, even in the same species. The analysis showed that trees with excellent cold tolerance included Q. glauca Thunb., C. japonica, R. indica, and the thorn tree. This knowledge is required for the evaluation of the possibility of the survival of trees under cold temperature conditions in cities.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.109-114
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• 2011

A breeding population of Quercus glauca has been established via simple direct selection. Seedlings from naturally crossed seeds of 35 selected families growing in Jeju Island were placed using stroll repeated planting into two experimental forest located at Hannam and Sanghyo in Jeju. After 3 years of planting, characteristics of growth were examined. Growth pattern of trees in Sanghyo was better than those in Hannam. The average heights of filial were 66.8 cm in Hannam and 92.5 cm in Sanghyo. Root collar diameters of filial in Hannam and Sanghyo were 9.3 mm and 12.2 mm, respectively. A great weather differences especially in precipitation and temperature were shown between two test sites. The result of difference of growth pattern between two sites could be useful in provenance adaptability test. Data within families and individuals obtained from this study was also useful for establishment of seed orchard of Q. glauca.

• Journal of Intelligence and Information Systems
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• v.29 no.1
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• pp.377-396
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• 2023

As the cryptocurrency market continues to grow, it has developed into a new financial market. The need for investment strategy research on the cryptocurrency market is also emerging. This study aims to conduct an empirical analysis on an investment methodology of cryptocurrency that combines short-term trading strategy and deep learning. Daily price data of the Ethereum was collected through the API of Upbit, the Korean cryptocurrency exchange. The investment performance of the experimental model was analyzed by finding the optimal parameters based on past data. The experimental model is a volatility breakout strategy(VBS), a Long Short Term Memory(LSTM) model, moving average cross strategy and a combined model. VBS is a short-term trading strategy that buys when volatility rises significantly on a daily basis and sells at the closing price of the day. LSTM is suitable for time series data among deep learning models, and the predicted closing price obtained through the prediction model was applied to the simple trading rule. The moving average cross strategy determines whether to buy or sell when the moving average crosses. The combined model is a trading rule made by using derived variables of the VBS and LSTM model using AND/OR for the buy conditions. The result shows that combined model is better investment performance than the single model. This study has academic significance in that it goes beyond simple deep learning-based cryptocurrency price prediction and improves investment performance by combining deep learning and short-term trading strategies, and has practical significance in that it shows the applicability in actual investment.

• Landscaping Tree
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• s.108
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• pp.26-28
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• 2009

가시나무는 상록활엽교목(常綠闊葉小喬木)으로 겨울철에도 녹색의 아름다움을 지니고 있다. 종류로는 붉가시나무(Quercus acuta), 종가시나무(Q glauca), 가시나무(Q. myrsinaefolia)가 대포수종으로 우리나라 남부지방의 제주도를 포함한 도서지방과 해안지방에 많이 식재되어 있다. 원정형(圓頂形)의 수형이 미려(美麗)하고, 내조성(耐潮性)이 강해 해안의 정원수, 공원의 조경수 등으로 널리 사용되고 있는데 이들에 대한 해충에 대한 정보가 부족하여 이들을 가해하는 주요해충 종에 대해서 생태 및 방제법을 소개하고자 한다.