• Journal of Environmental Science International
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• v.19 no.9
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• pp.1137-1142
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• 2010

This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= $P_4P_4L_2$ < $P_7P_1L_2$ = $P_5P_3L_2$ < $P_6P_2L_2$. For the soil thickness of 25cm, the plant height was increased in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86~90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.1
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• pp.85-95
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• 2008

This study was carried out to analyze Sungkyunkwan University Forest vegetation at Pocheon. Employing the releve method of Braun-Blanquet, 20 plots were sampled. The communities were classified into Larix leptolepis community, Quercus mongolica community, Pinus koraiensis community and Pinus densiflora community. Average coverage rate was 91% in tree layer, 39% in subtree layer, 44% in shrub layer, 43% in herb layer, respectively. The importance values were 61.79% in Larix leptolepis, 52.08% in Quercus mongolica, 44.6% in Pinus koraiensis, 30.35% in Pinus densiflora, 17.78% in Styrax obassia, 10.9% in Fraxinus rhynchophyllia. DBH range of most Quercus mongolica was between 6cm and 15cm. Therefore, Quercus mongolica will be dominant species in the study area for several more decades.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.145-156
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• 1998

On the basis of data obtained from 5 forest roads(Backyang, Byongatae, Saorang, Bukyu and Dangrim forest road) collapsed under a heavy rainfall in Chunchon, Kangwondo, this study was carried out to predict the cutting slope failure of forest road by using Quantification theory(II). The results were summarized as follows; The cutting slope failure was chiefly occurred by correlated action of road structure, vegetation and topographical factors. The cutting slope failure predicted by partial correlation coefficients and range values was characterized by longer than 8m of cutting slope length, depper than 2.5m of soil depth, between $30^{\circ}$ and $50^{\circ}$ of original ground slope gradient, absence of vegetation coverage on cutting slope, and greater than $60^{\circ}$ of cutting slope gradient. And the rate of correct discrimination by analysis of cutting slope failure was 90.1%.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.4
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• pp.1-10
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• 2011

This study was conducted to compare the growth of Zoysia japonica depending on different soil treatments in Saemangeum sea dike, which is filled with dredged soil. Zoysia japonica was planted using sod-pitching method on the control plot. On plots which were treated with forest soil and soil improvement, Zoysia japonica seeds were sprayed mechanically. Sixteen months after planting, coverage rate, leaf length, leaf width, and root length were measured and analyzed. Also, three Zoysia japonica samples per plot were collected to analyze nutrient contents. Coverage rate was 100% in B treatment plot(dredged soil+$40kg/m^3$ soil improvement+forest soil), in C treatment plots (dredged soil+$60kg/m^3$ soil improvement+forest soil), and D treatment plots (dredged soil+$60kg/m^3$ soil improvement), while only 43% of the soil surface was covered with Zoysia japonica on control plots. The width of the leaf on C treatment plots (3.79mm) was the highest followed by D treatment (3.49mm), B treatment (2.40mm) and control plots (1.97mm). Leaf and root length of D treatment was 30.18cm and 13.18cm, which were highest among different treatments. The leaf length of D treatment was highest followed by C, B, and A treatments. The root length of D treatment was highest followed by C, A, and B treatments. The nitrogen and phosphate contents of the above ground part of Zoysia japonica were highest in C treatment, followed by D, B, and A treatments. The nitrogen and phosphate contents of the underground part of Zoysia japonica were highest in D treatment, followed by C, A, and B treatments. C and D treatments showed the best results in every aspect of grass growth. The results of this study could be used to identify the cost effective way to improve soil quality for soil surface fixation on reclaimed areas using grass species.

• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.262-270
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• 2003

This study was carried out to analyze forest vegetation of Jinaksan in Geumsan, Chungnam Province. Employing the releve method of Braun-Blanquet, 26 plots were sampled in forest of Jinaksan. The communities were classified into Quercus mongolica, Quercus variabilis, Quercus aliena, and Pinus densiflora communities. Coverage rate was 79.4% in tree layer,27.6% in subtree layer,37.0% in shrub layer, 31.1% in herb layer, respectively. The importance values were 45.51 in Q. mongolica,44.17 in P. densiflora,26.56 in Q. variabilis,26.78 in Q. serrata,20.81 in Q. aliena, and 15.58 in Prunus serrulata var. spontanea, respectively. Most of the DBH in the Q. mongolica, Q. variabilis, Q. aliena, and p. densiflora was between 5 cm and 15 cm. Therefore, Q. mongolica, Q. variabilis, and Q. aliena will be dominant species in the study area for several decades.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.5
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• pp.28-39
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• 2003

This study was carried out to elucidate effective restoration measures for natural forest with recycling native tree un site from November 2001 to October 2002 to obtain a basic information for revegetation measure, eight experimental treatment was done and the length of stump, root-ball size of stump, antisepsis treatment of trunk cut, Planting season and contents of organic matter in soil were effective on regrowth of root-stock. Thirteen tree species including Quercus acutissima among twenty tree species showed outstanding sprout and survival rate(over 90 percent), Planting in November and combinated planting with 5 trees and 9 shrubs of root-stock per 100$m^2$ plot showed a good growth. And 10 percent of organic matter plot showed a good crown coverage.

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.1-17
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• 2001

Forming a part of "Cooperative Practical Study for the Modernization of the Management of National Forest", this study was conducted to provide overall ecological information for the natural regeneration of major tree species on the basis of community structural attributes in the deciduous forest ecosystem. Followings are summarized characteristics of the natural regeneration for the selected tree species. Betula costata : Although large number of seeds are dispersed by wind, they require mineral soils to germinate. Thick litter layer could be an obstacle to germinate. After germination, the seedling requires large amount of light for successful establishment. Acer mono : Characterized by high shade tolerance and weak drought resistance, the seedling should be overcasted with more than 50% of canopy coverage. High stand density should be maintained to produce good quality of timber. The potential of coppice may be high. Ulmus laciniata : Since this species needs high rate of troll moisture and light, around 60% of canopy coverage should be maintained to retain moisture and incoming light. The competition with other vegetation should be removed for the favor of successful seedling establishment. Fraxinus mandshurica : This species requires moist mineral soils to germinate. After germination, the seedling needs large amount of light and moisture for successful establishment. Site preparation should be applied to reduce competition with weedy vegetation. Fraxinus rhynchophylla : Interval of large seed crops may be highly varied. Thick litter layer could be an obstacle to germinate. Site preparation should be applied to reduce competition with weedy vegetation so as to achieve successful seedling establishment. Quercus mongolica : Including the difficulty of seed supply by the consumption, thick litter layer and mountain bamboo cover could be the obstacle to germinate. More than 50% of relative light intensity is necessary to achieve successful seedling establishment. Kalopanax pictus : Thick litter layer could be an obstacle to germinate. The seedling needs large amount of light and moisture for successful establishment. Abies holophylla : In spite of high shade tolerance, the growth rate in sapling stage may be extremely slow. Cornus controversa : Seeds (drups) are consumed and dispersed by animals, tending to be not sufficient in seed supply. This species requires large amount of light for successful germination and seedling establishment. Tilia amurensis : The difficulty of seed supply might be expected with low seed purity and double dormancy. Since thick litter layer could be an obstacle to germinate, the species requires moist mineral soils for successful germination. The potential of coppice may be extremely high.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.53-58
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• 2007

The Satellite Mobile Communication System holds several advantages, such as wide coverage that guarantees the communication in a huge area. It is suitable in the ocean and forest and especially in emergency situation. However, the licensed frequency is not always occupied within all coverage and all the time. The actual utilization rate is relatively low compared to other wireless communications such as cellular systems. There are a large amount of white spaces in its coverage. Therefore, it is necessary to consider introducing additional services such as data communication, in order to increase the spectrum utilization as well as the revenue of the Satellite service provider. In this paper, we first analyze the possibility to implement new services in the licensed band of satellite mobile phone by its provider. Then we address the most significant issue for the implementation of current service, which is how to accurately detect the satellite mobile terminals. Finally, we suggest two new possible solutions namely, eigenvalue detection based methods to find out the existence of transmitted signal from the satellite mobile terminals.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.49-54
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• 2011

Curtain coating has been considered as the best coating technology because it is a coating technology that forms contour coating layer with better coverage. To increase the curtain stability surfactants are being used. In this study, the effect of a surfactant on the stability of curtain coating colors was examined by evaluating dynamic surface tension with a bubble surface tensiometer. Di-2-ethylhexyl sodium sulfosuccinate was used as a surfactant since it showed low dynamic surface tension at low surface age. And we evaluated the influence of surfactant on coating color properties including surface tension, viscosity and curtain stability. The surface tension of coating color was decreased when surfactant addition was increased up to 0.5 pph, but it was leveled off at 0.3 pph of surfactant addition. With the increase of surfactant addition rate, viscosity of coating color were increased. Micelles formed by surfactant contributed to the increase of the viscosity. Curtain stability was improved with the addition of surfactant until it reached up to 0.5 pph. Excessive addition of surfactant (> 0.5 pph) didn't improve curtain stability. This was attributed to Marangoni effect(self-healing) and decreasing of curtain thickness.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.208-219
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• 2020

Forest thinning brought the large variation to forest ecosystem including environment and animal. Our study was result of long-term monitoring for ground-dwelling arthropod communities after thinning in forest ecosystem. In this study, we conducted field study on plantation forest in Chuncheon, Korea in 2018, and compared with previous study data (2006 and 2008). We found that the effect of thinning was still existent 10 years later from thinning with difference of habitat environment(depth of ground organic matter, coverage rate of ground vegetation and canopy). And ground-dwelling arthropod communities showed changes of abundance and taxa at the study area and thinning conditions. Ground-dwelling arthropod communities in 2018 were dominant in the order of Diptera, Hymenoptera, Coleoptera (Insecta), Araneae (Arachnida) and Collembola (Collembola). Among the conditions of thinning, Araneae (Arachnida), Coleoptera and Hymenoptera (Insecta) showed amount of abundance in heavy thinning. And Collembola (Collembola) and Diptera (Insecta) were most common in area of light thinning. In 2018 ground-dwelling arthropod communities, abundance of Diptera and Coleoptera (Insecta) and Isopoda (Crustacea) were decreased although Hemiptera and Orthoptera (Insecta) were increased than 2008 arthropod communities. Arthropod communities in 2018 were more similar with those in 2008 (after thinning) than with those in 2006 (before thinning).