• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.248-256
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• 2004

Dendropanax morbifera Lev.(Araliaceae), Korean endemic and evergreen small tree is a component of evergreen forest and mainly distributed in sourthern region and islands in Korea. The ecological characteristics of 4 natural stands of D. morbifera.(Sundol, Suak, Hannam, and Sangho populations in Cheju island) were studied. In most of the D. morbifera natural stands, the following tree species appeared predominantly: Castanopsis cuspidata var. sieboldii, Carpinus laxiflora, D. morbifera, Quercus glauca, Quercus myrsinaefolia, Camellia japonica, and Acer pseudo-sieboldianum. Two tree species, such as C. cuspidata var. sieboldii and C. laxiflora appeared in the all investigated stands. D. morbifera occupied 17.2% of the upper story, 12.9% of the middle story, and 10.3% of the lower story, respectively. The distribution patterns by Morisita' s Index showed that D. morbifera was distributed randomly in the three stories. The frequency distribution of DBH D. morbifera species showed reverse J-shaped, therefore it seems to remain as a dominant species.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.7-12
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• 2019

The application of neural networks to stock forecasting has received a great deal of attention because no assumption about a suitable mathematical model has to be made prior to forecasting and they are capable of extracting useful information from data, which is required to describe nonlinear input-output relations of stock forecasting. The paper builds neural network models to forecast daily KOrea composite Stock Price Index (KOSPI), and their performance is demonstrated. MAPEs of NN1 model show 0.427 and 0.627 in its learning and test, respectively. Based on the predicted KOSPI price, the paper proposes an alpha trading for trades in Exchange Traded Funds (ETFs) that fluctuate with the KOSPI200. The alpha trading is tested with data from 125 trade days, and its trade return of 7.16 ~ 15.29 % suggests that the proposed alpha trading is effective.

• Journal of the Korean Institute of Rural Architecture
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• v.23 no.1
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• pp.43-50
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• 2021

This study aims to investigate and analyze the utilization perception of members of head families based on a survey on the history, folklore, architectural resources of head families. In order to identify the direction of utilization of Jeonnam head family resources, tangible and intangible resources, and spaces and places to contain programs were researched. The results of the study were summarized as follows. 1) Head family houses in Jeonnam could be categorized into head families that preserved the original form of head family houses, head families that preserved a part of head family houses, head families that newly built head family houses while the original forms thereof have disappeared, and relocated head families of which eldest grandsons no longer reside, where only the sites of the head family houses remain or relocated to a different place. 2) In the case of perception of members of head families on the utilization of head family resources, 27 head families consented to the utilization, 35 head families opposed to the utilization, and 6 head families were undecided on the utilization out of a total of 68 head families. 3) The results of investigating and analyzing the desired type of programs of each head family by categorizing the programs into lodging, food, meditation, education, and tourism, as many as four programs were desired, while some families desired 2 or 3 programs at the lowest, showing an overlapping characteristic.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.294-302
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• 2016

This study was conducted to evaluate aboveground tree biomass and nutrient (C, N, P, K, Ca, and Mg) response of tree components by high (1,933 trees $ha^{-1}$) and low (1,200 tree $ha^{-1}$) stand densities in a 27-year-old Quercus glauca plantation. The study site was located in Goseong county, Gyeongsangnam-do, southern Korea. Total 12 trees (6 high and 6 low stand densities) were cut to develop allometric equations and to measure nutrient concentration of tree components. Stand density-specific allometric equations in the high and low stand densities were significant (P < 0.05) in tree components with diameter at breast height (DBH). Also, generalized allometric equations could be applied to estimate tree biomass regardless of the difference of stand density because of no significant effect on slope of stand density-specific allometric equations. Aboveground tree biomass estimated by the allometric equations was significantly higher in the high stand density (177 Mg $ha^{-1}$) than in the low stand density (114 Mg $ha^{-1}$). However, nutrient concentration of tree components was not significantly affected by the difference of stand density. Nutrient stocks in tree components were not significantly between the high stand density and the low stand density, except for the N and P stocks of stem wood. These results indicate that aboveground tree biomass could be significantly affected by stand density, but nutrient concentration among the tree components was not affected by the difference of stand density in a Quercus glauca plantation.

• Korean Journal of Environment and Ecology
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• v.18 no.4
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• pp.369-381
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• 2004

This study was achieved to present the way to restore the Seonheulgot pasture-grassland damaged by landuse and interference for a long time to evergreen broad-leaved forests as the native vegetation structure. As a result of analyzing ecological succession tendency of structure in survey area, we established the optimal restoration model. The total of survey sites were 26, and the classified plant community types were four types by M.I.P of dominant woody species. Finally we classified the four types based on diameter of dominant woody species in canopy layer. The six community types are as follows: Community I was runner-shrub forest, community II was evergreen broad-leaved shrub forest, and community III was evergreen broad-leaved forest of small diameter. Community IV and V were evergreen broad-leaved forest of middle diameter. Community Ⅵ was evergreen broad-leaved forest of large diameter. The number of constituent species was 24 in community I, 28 in community II as the shrub forest, 16 as the evergreen broad-leaved forest of small diameter, 29 in community III, 30 in community IV as the evergreen broad-leaved forest of middle diameter and 27 in community Ⅵ as the evergreen broad-leaved forest of large diameter. The range of Shannon's index of all communitys was from 0.8763 to 1.2630 and the Similarity index between the community composed of middle diameter woody species and large diameter woody species. The ecological succession of community I, II, and III were changed from pasture-grassland to broad-leaved forest and the structure of community IV, V, and Ⅵ was similar to evergreen broad-leaved forest in warm temperate region. We suggest the restoration planting model evergreen broad-leaved forest of in Seonheulgot pasture-grassland, as follows: The target restoration vegetation were Castanopsis cuspidata var. sievoldii community and Queycus glauca community. Castanopsis cuspidata var. sievoldii and Quercus glauca should be dominant woody species in canopy layer, the number of trees was 10 per 100$m^2$, and Castanopsis cuspidata var, sievoldii, Quercus glauca, Camellia japonica, and Eurya japonica should be dominant woody species in the understory layer, the number of trees was 14 per 100$m^2$.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.157-177
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• 2022

Investors are trading stocks by keeping a close watch on the order information submitted by domestic and foreign investors in real time through Limit Order Book information, so-called price current provided by securities firms. Will order information released in the Limit Order Book be useful in stock price prediction? This study analyzes whether it is significant as a predictor of future stock price up or down when order imbalances appear as investors' buying and selling orders are concentrated to one side during intra-day trading time. Using classification algorithms, this study improved the prediction accuracy of the order imbalance information on the short-term price up and down trend, that is the closing price up and down of the day. Day trading strategies are proposed using the predicted price trends of the classification algorithms and the trading performances are analyzed through empirical analysis. The 5-minute KOSPI200 Index Futures data were analyzed for 4,564 days from January 19, 2004 to June 30, 2022. The results of the empirical analysis are as follows. First, order imbalance information has a significant impact on the current stock prices. Second, the order imbalance information observed in the early morning has a significant forecasting power on the price trends from the early morning to the market closing time. Third, the Support Vector Machines algorithm showed the highest prediction accuracy on the day's closing price trends using the order imbalance information at 54.1%. Fourth, the order imbalance information measured at an early time of day had higher prediction accuracy than the order imbalance information measured at a later time of day. Fifth, the trading performances of the day trading strategies using the prediction results of the classification algorithms on the price up and down trends were higher than that of the benchmark trading strategy. Sixth, except for the K-Nearest Neighbor algorithm, all investment performances using the classification algorithms showed average higher total profits than that of the benchmark strategy. Seventh, the trading performances using the predictive results of the Logical Regression, Random Forest, Support Vector Machines, and XGBoost algorithms showed higher results than the benchmark strategy in the Sharpe Ratio, which evaluates both profitability and risk. This study has an academic difference from existing studies in that it documented the economic value of the total buy & sell order volume information among the Limit Order Book information. The empirical results of this study are also valuable to the market participants from a trading perspective. In future studies, it is necessary to improve the performance of the trading strategy using more accurate price prediction results by expanding to deep learning models which are actively being studied for predicting stock prices recently.

• The Korean Journal of Financial Studies
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• v.5 no.1
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• pp.191-212
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• 1999

1997년에 우리 나라는 외환충격으로 인한 금융위기 속에서 시장가격이 급격하게 변동하였다. 이로 인해 차익거래를 가능하게 하는 차입과 대출이 크게 제약되었고, 이것은 시장간 균형관계에 중요한 영향을 줄 수 있다. 이에 이러한 금융위기에서도 주요 시장간의 균형관계가 유지되었는지를 검정하는 것이 이 연구의 목적이다. 분석자료로 KOSPI 200 현물 종가 및 선물 결제가격, 연간 회사채 수익률, 양도성 예금 연간이자율, 기준환율의 일일 자료를 사용하였다. 1996년 5월 3일부터 1998년 5월 21일까지의 기간을 외환충격에 의한 금융위기 전, 중, 후의 3단계로 구분하여 각 단계별로 백터오차수정모형 분석과 충격반응분석을 하였다. 금융위기 이전인 제1단계에서는 5개 내생변수간의 균형관계가 존재하였다. 금융위기가 급속하게 진행된 제2단계에서는 균형관계가 존재하지 않았다. 그러나 주가지수, 주가지수 선물가격 및 기준환율 변수를 내생변수로 하고, 나머지 변수를 외생변수로 분석한 경우에는 균형관계가 존재하였다. 금융위기 진정단계인 제3단계에서는 5개 내생변수간의 균형관계가 성립하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.612-617
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• 2014

It is generally known that the automotive road wheel involves the non-proportional multiaxial loading condition, therefore the measuring dynamic stress and strain in driving state is very important to predict an endurance characteristic of the automotive road wheel. In this study, the ultimate driving test using F1 circuit with respect to 2 kinds of velocity conditions have been carried out in order to measure dynamic stress, strain of the wheel and acceleration of a vehicle. Based on the measured results, the characteristics of dynamic stress generation have been analyzed, and factors which have effect on the dynamic stress generation have been studied.

• Journal of Information Management
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• v.29 no.3
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• pp.27-42
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• 1998

Responding to the growing trend of Internet information resources, national policies to develop, preserve, and supply those resources are needed. The purpose of this paper is mainly to review and analyze some cases of foreign countries, and to build a model for national policy on internet archive in Korea.

• Journal of the Korean Institute of Rural Architecture
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• v.10 no.2
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• pp.1-8
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• 2008

This paper is aimed to clarify the conservation and reuse of historic areas in modern ages, especially focused rural settlement Honbul village, Namwon city. Honbul village has modern historic areas as well as the korean traditional head houses, and so many narratives. There are old Seodo station building and the other facilities centered on these areas. And so this paper is to conserve and reuse not only this station but also traditional head house as modern cultural assets for revitalizing Honbul village. This study has been done by the field survey and interviews on the basis of the blueprint and its conditions. Through these modern historic areas, it would be for visitors experiencing the sustanable living condition from now on, excellent landscape of Honbul village. And also development of agricultural products and brand naturally increase incomes of farm families, and finally it will go far toward solving the rural problems.