• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.120-131
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• 2009

This study measured the centripetal force and effective scope of the population spread from urban center and subcenters in order to diagnose the urban spatial structure of the formation of a multicentric city structure in Busan. The study analyzed the variability of the determination coefficient value (R square) with a negative exponential function derived from the population density model by extending the circular region into 5-km units. The aim of this study was to measure changes in the effective scope of the population centripetal force of the urban center and subcenter in 5-year intervals from 1995 to 2005 using census data. The explanatory adequacy of the population density function was examined with the bias of the function to calculate the distance error between the real location of the urban center and the optimal location, according to the population density function. To summarize the results, the value for the area of Jungangdong showed a continuous reduction, whereas Seomyeon (Bujeondong) maintained explanatory adequacy without a large change. As a whole, Busan was in the process of continuous diversification, in spite of its reduced population. Therefore, it appears necessary to strengthen the function of the urban center and subcenter and to supply adequate dwelling zones close to downtown to form a more efficient urban spatial structure. The results of the present study will be utilized as basic data for the formulation of a political approach to the efficient reorganization of spatial structure by correlating concrete spatial information with the population variability of Busan's urban center and subcenter.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.3
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• pp.54-60
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• 2013

This study carried out a phytosociological research by Z.-M. school's method describing vegetation structure and management solution about nutmeg tree's(Torreya nucifera ) forests. The nutmeg tree's forests have developed intervale and hills in warm-temperate evergreen broad-leaved forests zone. The nutmeg tree's forests composed 50 familly, 80 genus, 88 species divided two syntaxa(typical sub-community, Arachniodes aristata sub-community) by species composition and correspond to habitat condition. The nutmeg tree's forests show a uniform forest's structure which composed 3~4 layer of sub-tree and shrub. And it was worthy of special mention which characterized diagnostic species of Camellietea japonicae in the warm-temperate evergreen broad-leaved forests. In case of forests floor, were a high rate in order of Ophiopogon japonicus, Polystichum tripteron, Arisaema ringens. And Oplismenus undulatifolius which represent mantle communities as well. This indicates that the nutmeg tree's forests are exposed by humman effects sustainedly. The nutmeg tree's young trees appeared a high rate at half shade and shade. The vigorous tree species have to spacing cutting instead of the heavy thinning that consist in with a shout of declining astructur and function of the forest ecosystem for maintaining a nutmeg tree's forests. And we suggest for the density regulation of the sub-tree and shrub. In conclusion, need to the continuous monitoring about the vegetation structure and management solution for the sustainable nutmeg tree's forests.

• Tunnel and Underground Space
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• v.24 no.5
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• pp.335-343
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• 2014

Room-and-pillar mining method is one of the most popular underground mining method in the world. If the room-and-pillar mining method is able to be adopted in civil works, it would be highly probable to reduce underground construction costs and to expand a underground structure in use. Therefore, this study aims to analyze the design procedure of unsupported rock pillars which are indispensable to ensure the stability of a room-and-pillar underground structure. Parametric studies on their key design parameters are also carried out for 125 different kinds of design conditions. From the study, the width of a rock pillar is found to show a linear relationship with its corresponding safety factor. The safety factor of a unsupported rock pillar decreased drastically like a negative exponential function as the ratio of room width to pillar width increases in the same rock strength condition. Based on the parametric studies, a design chart to simply evaluate the geometric design parameters of a unsupported rock pillar satisfying a design safety factor is also proposed in this study.

• Journal of Environmental Policy
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• v.12 no.4
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• pp.119-132
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• 2013

Hosta longipes is one of the most popular ornamental perennials in use in Korea today, and is mainly used as a groundcover plant in urban shaded places. In this study, the pytoremediation effect of Hosta longipes was tested using four concentrations (Control, 100, 250 and $500mg{\cdot}kg^{-1}$) of Cd, Pb and Zn in soil. The plants were planted in $300mm{\times}200mm{\times}250mm$ drainless-containers, which were filled with a artificial amended soil for 7 months. The results showed that the contents of heavy metals cadmium and lead in the shoot of Hosta longipes increased with increasing heavy metal concentration levels exception of zinc. The amount of zinc, cadmium, and lead accumulated in roots were increased with heavy metal concentration levels up in soil. The shoot/root ratios(TF; translocation factor) values were found to be more than 80% of total Zn, Cd, and Pb take up by Hosta longipes. These results indicated that root is the major part for accumulation of heavy metal. The removal contents of zinc, cadmium, and lead increased significantly with the increasing heavy metal concentration in the soil, which was planted with Hosta longipes. The heavy metal concentration accumulation in plant/soil ratios (BF; bioaccumulation factor) values for three metals were found to be more than 30% in cadmium and lead, but lower in zinc treatments. The different responses of Hosta longipes suggest that in heavy metal contaminated soils the plant adsorbs available metals depending on the concentration soils in which they are present. Therefore, this species can be an efficient phytoremediator for soils contaminated with cadmium and lead in urban shaded places.

• The Korean Journal of Food And Nutrition
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• v.13 no.5
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• pp.483-489
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• 2000

Wild Chopi leaves were harvested near Chounghwa Mt. Sangju city in Kyungpook province. Chopi leaves were dried naturally and crushed with and without blanching. From mechanical analysis(GC). fifty five peaks were identified as volatile materials in no blanching leaf. Among the fifty five peaks, twenty three peaks were identified as hydrocarbones(dodecane, sabinene, myrcene etc.), ten peaks as alcohols (isobutylalcohol. cis-pentenol, 1-pentenol, 1-penten-3-ol etc.), seven peaks as aldehydes (3-methylbua-tanal, hexanal, 2,6-dimethyl hept-5-al etc.), four peaks as ketones(3-hydroxy-2-butanone, 2-nonanone, 2-undecanone, 2-tridecanone) and six peaks as esters ( cis-3-hexenyl acetate, linalyl acetate. citronellyl acetate, nervy acetate etc.). Other peaks were founded as 3-cyano-2,5-dimethylpyrazine, dimethyl sulfide, chloroform, 1,8 cineole. Thirty five peaks were identified as volatile materials in blanching leaf. Twenty peaks were identified as hydrocarbones(1,1-oxybis-ethane, $\alpha$-pinene, camphene. myrcene, $\beta$-phellan-drene, $\beta$-caryophyllene etc.), as alcohol(L-linalool, (-)-isopulgerol, $\alpha$-terpineol. citronellol etc.), as aldehydes(nonanal, citronellal), as ketones(2-undecanone, 2-tridecanone etc.) and as esteres(citronellyl acetate. cis-3-hexenyl acetate, neryl acetate etc.). Other peaks were found as 3-cyano-2,5-dimethyl-pyrazine. The amount of volatile materials such as $\alpha$-pinene, myrcene, $\beta$-phellanderene, L-linalool, citronellal, citronellyl acetate, $\beta$-caryophyllene were detected abundantly among the volatile materials.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.151-157
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• 2003

This research was conducted to investigate about structural characteristics of vegetation by change of the environmental factors for prolific open-pollinated progeny forest in Pinus koraiensis stands. Stand slope of Kapyung area was slower than Youngdong area. On the other hand, contents rate of the soil chemical properties in Kapyung was lower than Youngdong area. And relative intensity of light was higher Youngdong than Kapyung area. On the whole, growth of the Pinus koraiensis was more dominant Kapyung area than Youngdong. Analysis result of the relative density, - frequency, - coverage and importance value to shrub layer in each local stands, Quercus mongolica and Quercus acutissima were dominant species in Kapyung area. Dominant species In Youngdong area was Quercus acutissima. In Kapyung area, appearance species of the vegetation layer was consisted that live in moist soil and shaded lot. Youngdong area showed fewer species than Kpyung area. Species diversity of shrub and vegetation layer in Kapyung and Youngdong area was higher than Youngdong. This result was judged by slope difference between each areas. Kapyung area need enforce thinning and Youngdong area conduct tending management on shrub layer.

• The Journal of Engineering Geology
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• v.20 no.4
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• pp.425-436
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• 2010

We established a stochastic 3-D fracture network system for fractured rock masses located in Il-Gwang Mine, Busan, to explore the relationship between the acidity of mine drainage and fracture geometry. A field scanline survey and borehole image processing were performed to estimate the best probability distributions of fracture geometry parameters. The stochastic 3-D fracture network system constructed for the rock masses was validated and deemed to be successful. The 3-D fracture network model was suitable for developing conceptual ideas on fluid flow in fractures at a field experimental site. An injection well and three observation wells were drilled at the field experimental site to monitor the acidity of mine drainage induced by the injection of fresh water. The field experiment, which was run for 29 days, yielded a significant relationship (with a high coefficient of determination) between the fracture geometry parameters and the acidity of mine drainage. The results show that pH increased with increasing relative frequency of fracture strike, and decreased with increasing fracture density. The concentration of $SO^{2-}_4$ decreased with increasing relative frequency of fracture strike, and increased with increasing fracture density.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.307-313
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• 2003

Japanese pine sawyer, Monochamus alternatus, is a primary vector of pinewood nematode, Bursaphelenchus xylophilus in Korea. Emergence characteristics of the adults were studied in Jinju, Korea using dead pine logs in which the larvae of the sawyer overwintered from 1999 to 2002. Emergence data showed that the adults began to emerge out of the logs in sunny place from May the 15th in average of the four years. Cumulative emergence ratio (CER) reached at 50% at mid-June, and the emergence terminated by early or late July depending on years. In shady place, however,50% CER was reached 17 days later than in sunny place. The 50％ CER of males reached 1 to 4 days earlier than that of females depending on years. Of the adults emerged from the logs collected from February to April in 2001, 97.6％ was univoltine, and the rest was biennial which emerged from May to July of the next year. Female and male adults emerged throughout 24 hours; 32.3% of the total adults emerged from 8 to 12 a.m. It took 68.0 seconds for the adults to escape from pine logs.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.447-456
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• 2013

This study was carried out for the establishment of theory and foundational data for breeding, on variegated foliage plants using for potted plants, based on examination and analysis for shape, color, and area ratio of variegated leaves and chlorophyll contents. Six families, 18 genus, and 54 species of variegated plants domestically distributed in Korea were used as the plant materials. Patterns based on chlorophyll-deficient part in variegated leaves were divided into 20 types, such as steps, border, collapsed border, sandy border, half, silk, stars, vein, firewood, border and firewood, center, entirety, leaf, irregular, net, watermelon, melon, and so on. There were 10 kinds of colors including dark green, red, dark red, reddish white, reddish yellow, white, silver, silvery white, yellowish white, and yellow. The ratio of variegated area was ranged from 5.8% to 100% and it was diverse depending on species or cultivar. The ratios by patterns were highest in entirety (98.6%) and relatively high in step (60.8%), whereas, low in boarder, star and firewood (33.6-36.4%), and relatively low in half and vein (43%). Chlorophyll content of variegated leaf was rather lower compared to normal plants and chlorophyll b tended to be higher in ratio of chlorophyll a to b. Particularly content of chlorophyll b in Stromanthe sanguinea 'Triostar', Dracaena fragrans 'Massangeana Compacta', D. reflexa 'Song of India', and Tradescantia spathacea was higher than chlorophyll a in comparison with that of normal plants.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.151-159
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• 2008

Performances of retroreflectivity vary place to place, according to traffic volumes and time lengths after striping, depending on pavement marking materials and colors. The present paper uses the nation wide data of retroreflectivity, which has been collected from freeways and then tries to develop the regression curve setting traffic volume and service life as independent variables and retroreflectivities as dependent variables. The DB system includes two year's measurement in $2005{\sim}2006$ over Korean freeway pavement marking at an interval of three months for the period. The mobile measurement system, a laserlux, was employed for the purpose. The DB has provided a lot of information about materials and performance of the specific pavement marking such as geometric features, traffic volumes, material characteristics and the installation date. This study provides the comparison of pavement marking performances under diversified conditions. Based on accumulated pavement marking performances, this study provides performance curves based on the diversified factors. The goal of the retroreflectivity modeling is to develop equations that can be used to estimate an average retroreflectivity of pavement markings as a function time since application and traffic volume. After representing the variation of retroreflectivities and estimating regression curves by linear, exponential, logarithmic and power function, the regression curve which had the highest coefficient of determination and the value similar to the last field measurement was regarded as the retroreflectivity decay model. As a result of verification, the decay model showed the signification within the 90% confidence level and especially showed the clear relation with field data according to increase of cumulative vehicle exposure. Accordingly, these models can be used to determine service lives, retroreflectivity degradation rates, and retroreflectivity of new markings.