• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1858-1863
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• 1991

The theory of stock option pricing has, recently, attracted attention of many researchers interested not only in finance but also in statistics and control theory. In this field, the problem of estimating stock return volatility is, above all, of great importance in calculating actual stock option value. In this paper, we assume that the stock market is represented by the stochastic volatility model which is the same as that of Hull and White. Then, we propose an approximation function of option value. It is a type of Black-Sholes option formula in which the first and the second order moments of logarithmic stock value are modified in a special form from the original model. Finally, an algorithm of estimating the parameters of the stochastic volatility model is given, and parameters are estimated by using Nikkei 225 index option data.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.289-302
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• 2018

The study investigated the forest vegetation in 59 plots between June 2017 and August 2017 to understand the forest vegetation structure of the protected zone for forest genetic resource conservation (forest genetic resource reserve area) in Heuksando Island. We classified the vegetation using the Z-M phytosociological method analyzed the importance value and species diversity of each vegetation classification. The analysis showed the Camellia japonica community group at a top level of forest vegetation hierarchy. In the level of community, it was classified into Dendropanax morbiferus community (Vegetation unit 1; VU 1), Carpinus turczaninowii community, and C. japonica typical community (VU 6). C. turczaninowii community was subdivided into Buxus koreana group (VU 2), Rhododendron mucronulatum group (VU 3), Vitis amurensis group (VU 4) and C. turczaninowii typical group (VU 5). Therefore, it was classified into a total of six vegetation units (one community group, three communities, and four groups). The analysis of the mean codominant value of each VU show that Quercus acuta was the highest in VU 1, C. turczaninowii in VU 2, Pinus thunbergii in VU 3, Pinus densiflora in VU 4, and Castanopsis sieboldii in VU 5 and VU 6. The analysis of species diversity showed that VU 2 was the highest among six units in species richness index, species diversity index, and species evenness index. VU 6 showed the highest among six units in species dominance index. In conclusion, a synecology approach to manage six units and twelve species groups was needed for the forest vegetation of Heuksando Island protected area for forest genetic resource conservation.

• Journal of Korean Society of Rural Planning
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• v.25 no.4
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• pp.77-86
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• 2019

The purpose of this study is to survey and analyze the operating state and characteristics of domestic and foreign green care, prioritize the facilities and programs for green care introduction through expert survey of importance, and thereby to provide a basic material for introducing green care in facilities in Rural Development Project districts, including domestic rural experience facilities. Domestic and foreign literature was analyzed in order to classify the necessary facilities programs, of green care, and the analysis results were modified and supplemented through Expert Delphi Survey. Based on the results, AHP based importance survey was conducted. In terms of the facilities and programs for green care introduction, necessary facilities (H/W) were categorized into four types (accommodation facility, resting facility, experience facility, therapy facility) and S/W programs into three types (learning experience type, therapy type, and care type). To verify the reliability of the AHP based importance survey, Consistency Index (C.I.) was analyzed. As a result, the C.I. value of nine respondents ranged from 0.000 to 0.083 so that the survey was found to have high consistency. The importance of S/W programs was 0.627, and that of H/W facilities was 0.373. For green care introduction, programs were found to be more important. Regarding the categories of necessary facilities, therapy facility had the highest value, or 0.348; experience facility 0.253; accommodation facility 0.211; resting facility 0.188. Therefore, therapy facility and experience facility were found to be important. In case of S/W programs, therapy type had the highest value, or 0.499, and learning experience type (0.255) and care type (0.246) were similarly important. Generally, the categories that had high importance values tended to show a remarkable difference in importance of their sub categories. In particular, facilities or therapy programs using natural ecology and forests were found to be highly important. In conclusion, it is required to actively review the introduction of active programs using resources, such as existing experience facilities and accommodation facilities and villages forests, and programs making the body and soul comfortable, such as natural ecology experience, Green Shower, and horticulture activity.

• Journal of Korea Trade
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• v.25 no.6
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• pp.126-142
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• 2021

Purpose - This study discusses the effects of human capital in the formation of GVC linkages. We also investigate GVC intensity between Korea and ASEAN. Design/methodology - To solve the doubling-counting problem in evaluating comparative advantage, RCA has been re-computed using domestic value-added (henceforth RCA_VA) at the country-sector level instead of value of trade. The impact of human capital on GVC intensity was empirically analyzed by establishing a panel data set with four industries (ISIC Rev. 4) in eight ASEAN countries from 2005 to 2015 from OECD-TiVA and WDI. Findings - The empirical results show that human capital has a negative effect on GVC intensity in the agriculture and manufacture industries, while it has a positive effect in the service and information industries. The results do not mean that low human capital is a barrier and inefficient to GVC linkages. Low Value-added activities may be more profitable to some emerging countries. These findings suggest that it is important to accurately identify the competitive elements to increase gains from trade under the GVC. Also, it shows that comparative advantages can be misled by an RCA index evaluated in trade volume under the GVC. Originality/value - This study highlights the importance of human capital as a factor for the efficient formation of Global Value Chain (GVC). This study has different from the literature in analyzing the role of human capital in formation of linkage of the GVC. And we clarify the changing patterns of trade by removing the double-counting problem under the GVC.

• Journal of Environmental Science International
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• v.24 no.5
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• pp.689-697
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• 2015

Based on the survey of 4 universities in Tai' an by questionnaire survey and interviews, this study acquired and analyzed the college student users' activity type, utilization frequency, retention time, companion, preference for landscape design style, the importance of the courtyard space's environment and landscape, as well as correlations between primary attributes and activity characteristics of student users. The weight of the university teaching area's courtyard space evaluation index was obtained by Analytical Hierarchy Process. The results indicated that nearly 60% college students select to study and to rest alone as the main activity type, 80% students' utilization frequency is at least two times or more a week. In addition, the relative weight of plant landscape is the highest in the 2nd class indexes of space garden landscape, and its value is 0.113; the relative weight of cleanliness is the highest in the 3rd class indexes of space environment quality, and its value is 0.143. Therefore, it should be attached much importance to constructing the environment and landscape for studying and relaxing, and the factors of cleanliness and plant landscape etc in the further design of courtyard space are taken into full consideration.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.2
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• pp.75-91
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• 1991

This study is one of studies on the analysis of vegetation spatial image and visual preference of roadside slopes in Chi-Ri Mt. national park. In this article, we analized the soil characteristics and the actual vegetation within slopes and forest lands contiguous to those. The results obtained were summarized as follows; The physical and chemical properties of soil in forest lands were better than slopes and Cheoneun temple - Seongsam pass was the best fertilized among 3 sector. In the structure of woody plants in forest lands, the high importance value species were Pinus denciflora, Quercus aliena within Ukmojeong-Deokdong sector, Q. aliena, Q. varabilis, Q. serrata within Banseon-Seongsam pass sector, and P. denciflora, Q. dentata within Cheoneun temple-Seongsam pass sector. And also, Aster scaber, Arundinella hirta, Pteridium aquilinum were the high importance value herbs within all sector. In slopes, the species diversity indices of woody plants were low, but that of herbs showed slightly high. By the cluster analysis used in similarity index, it was observed that woody plants structure between slopes and forest lands made little, but the herbs made slightly higher than woody plants.

• Journal of Forest and Environmental Science
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• v.31 no.2
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• pp.126-135
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• 2015

This study was conducted to evaluate the ecological characteristics of forest cover types which were classified by cluster analysis in the natural forest of Sobaeksan on the basis of the vegetation data from the point-quarter sampling method. Recognized forest cover types were 1) Mixed mesophytic forest, 2) Taxus cuspidata forest, 3) Fraxinus rhynchophylla-Quercus mongolica forest, 4) Betula ermanii forest, 5) Pinus densiflora forest, 6) Quercus mongolica mixed forest, and 7) Quercus mongolica pure forest. For those of classified types, the species composition was expressed by importance value (IV) to describe the community floristically. The species diversity was quantified using the Shannon's diversity index. The results showed that the forest cover types were characteristically different from one another in growing species and compositional rates, depending upon the type which was formed by a number of similar vegetational sample points. Species diversity indices (H') of total and overstory both were the highest in the mixed mesophytic forest (3.530 and 2.880, respectively), and lowest in the Q. mongolica pure forest (2.122 and 0.000, respectively) with only one canopy species. The highest species diversity in the mixed mesophytic forest may due to the relatively high species richness and evenness in the forest cover types. The description on ecological characteristics were suggested to understand the formation and development of forest cover types in this study area.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.701-710
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• 2011

The purpose of this study is to investigate the vegetation structure and ecological restoration of disturbed forest due to artificial plant. To this end, 12 plots were set up and surveyed. The result analyzed considering mean importance percentage(M.I.P) showed that the types were divided into three groups which are artificial planted forest type(three plots), natural forest-artificial planted forest type(four plots), natural forest type(five plots). Dominant proportion of artificial planted species were as follows: artificial planted forest type was over 60%, natural forest-artificial planted forest types were 14~49%. The range of Shannon's index of all associations was from 0.7131 to 0.7771(natural forest-artificial planted forest > natural forest > artificial planted forest). Also we suggested restoration method of vegetation for ecological value as follow: Control of density considering step and Remove of Pinus koraiensis seedlings of understory layer and shurb layer.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.177-183
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• 2016

Purpose: Mee (Madhuca longifolia) is an economically important tree growing throughout Sri Lanka. Its importance is mainly attributed to its oil with high nutritional and medicinal values. However, an inefficient extraction method limits its use. This study revealed the possibility of extracting oil from mee seeds by using a screw-type oil expeller. Methods: A popular screw-type oil expeller was used in the experiment. Extract bar clearance and speeds of the main spiral shaft were altered to increase the oil expelling efficiency of the machine. The quality of refined oil at the optimum oil yield was determined by measuring the refractive index, saponification value, iodine value, unsaponifiable matter, free fatty acid, and specific gravity. Results: An optimum yield of 35% oil was obtained when the machine capacity was 30 kg/h and energy consumption was 0.13 kWh/kg. This optimum machine condition was observed at an extract bar clearance of 0.5 mm and a main spiral shaft speed of 90 rpm. The refractive index, saponification value, iodine value, unsaponifiable matter, free fatty acid, and specific gravity of the oil were 1.4, 203, 59, 3.5%, 0.2%, and 0.907 g/cm3 respectively. Color of the mee oil was closer to yellow, which is revealed by the lightness value (L) of 24.93 and positive value (b) of 11.81. Conclusion: The screw-type oil expeller can be used for economically extracting mee oil on a commercial scale.

• Journal of Environmental Impact Assessment
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• v.19 no.6
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• pp.527-537
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• 2010

This study are Geumjung mountain fortress of the Busan Metropolitan City in the north gate of the East gate around the trail to identify the vegetation structure importance value, dominance, species diversity, similarity index analysis. Results of the study, plot on the western slopes elevation 423-636m, slopes of $15{\sim}20^{\circ}$ slope areas, Pinus densiflora, Pinus thunbergii, Quercus acutissima, Pinus thunbergii, Pinus rigida, Carpinus coreana, Quercus mongolica are fulfilling a community. Trees layer a height 8~12m, coverage 40~70%, sub-trees layer the height 3~7m, coverage 10~80%, shrubs layer the height 0.8~1.5m, coverage 20-30%, herb layer the height 0.1~0.5m, coverage 5-10% were in the range of plot in the east slope elevation 452-647m, slopes in the slope of $5-30^{\circ}$ and Pinus rigida, Pinus thunbergii, Pinus densiflora, Quercus mongolica, Quercus dentata, Carpinus coreana is fulfilling a community. The trees layer height 8~13m, coverage 0~70%, sub-trees layer the height 2~6m, coverage 0~80%, shrubs layer the height 0.8~1.5m, coverage 20-40%, herb layer the height 0.1-0.5m, coverage 5-40% were in the range. The survey showed to be in relatively good vegetation, but in some areas of Pinus rigida, Quercus acutissima, as was predicted in succession, the shrub layer in the plot of some dominated vine plants and vegetation management will be needed for this purpose respectively.