• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.347-365
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• 2020

In order to resolve traffic problems in urban areas and to increase the area of green spaces, tunnels in downtown areas are being increased. Additionally, the application of large port smoke extraction ventilation systems is increasing as a countermeasure to smoke extraction ventilation for tunnels with high potential for traffic congestion. It is known that the smoke extraction performance of the large port smoke extraction system is influenced not only by the amount of the extraction flow rate, but also by various factors such as the shape of the extraction port (damper) and the extraction air velocity through a damper. Therefore, in this study, the design standards and installation status of each country were investigated. When the extraction air flow rate was the same, the smoke extraction performance according to the size of the damper was numerically simulated in terms of smoke propagation distance, compared and evaluated, and the following results were obtained. As the cross-sectional area of the smoke damper increases, the extraction flow rate is concentrated in the damper close to the extraction fan, and the smoke extraction rate of the damper in downstream decreases, thereby increasing the smoke propagation distance on the downstream side. In order to prevent such a phenomenon, it is necessary to reduce the cross-sectional area of the smoke damper and increase the velocity of passing air through the damper so that the pressure loss passing through the damper increases, thereby reducing the non-uniformity of smoke extraction flow rate in the extraction section. In this analysis, it was found that when the interval distance of the extraction damper was 50 m, the air velocity passing through damper was 4.4 m/s or more, and when the interval distance of the extraction dampers was 100 m, the air velocity passing through damper was greater than 4.84 m/s, it was found to be advantageous to ensure smoke extraction performance.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.676-683
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• 2016

This study was conducted using the Wild -Tracker (WT-300, GPS-Mobile Phone Based Telemetry KoEco) to understand the habitats of the spot-billed duck wintering in urban and rural areas and provide the results as the basic data for the protection and management of the habitats of the waterbirds in Korea. Study areas consisted of the Anseong stream in Gyeonggi-do and the Sansu reservoir in Haenam. Five spot-billed ducks were captured by region, and we attached Wild-Tracker to each of the spot-billed ducks. We analyzed the tracking location data using ArcGIS 9.x and calculated Kernel Density Estimation (KDE) and Minimum Convex Polygon (MCP). The average home-range measured by MCP was $250.8km^2$(SD=195.3, n=5) in Anseong and was $89.1km^2$ (SD=69.6, n=5) in Haenam. 50% home-range measured by KDE was $21.8km^2$ (SD=26.9, n=5) in Anseong and $3.5km^2$ (SD=2.2, n=5) in Haenam, indicating a narrow home range in Haenam. During the winter season, both wetland and paddy field were mostly used as habitats in Anseong and Haenam. While the paddy field utilization rate was high in the daytime in Haenam, it was high in the nighttime in Anseong. By late winter, Haenam's day time paddy field utilization rate and Anseong's night time paddy field utilization rate increased.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.724-729
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• 2016

Environmental factors that affect the singing of cicadas have not been studied extensively, especially those affecting the cicadas' singing during the nighttime. Therefore, the objective of this study is to identify the effects of tropical night and light pollution on the cicadas' singing in a downtown area. The study sites were an apartment complex in Seocho-gu, Seoul, and the Chiaksan National Park in Wonju-si. The study subjects were Hyalessa fuscata and Cryptotympana atrata, which are the dominant species in Korea during summer. Cicada songs were recorded 24 hours a day, every day. The recording period was between July and August, lasting 25 days at the Seoul site and 14 days at the Chiaksan National Park. Temperature, precipitation, humidity, and amount of sunshine were selected as the environmental factors that potentially affect the cicadas' singing. Statistical analyses included correlations of meteorological factors with the cicadas' singing per hour, per 24 hours, and at nighttime (21:00~04:00). The results showed that: 1) H. fuscata began singing during the dawn hours, and the singing increased in intensity early in the morning. C. atrata's singing reached its peak in the morning and afternoon, ceased during sunset hours, thereby exhibiting a difference in the singing pattern of the two species. 2) The frequency of singing by H. fuscata decreased when C. atrata began to sing intensively in numbers, thereby exhibiting interspecific influence. 3) The results of the correlation analysis between meteorological factors and the singing of H. fuscata and C. atrata showed that both species tended to sing more when the temperature was higher and sang less on rainy days. 4) When limited to nighttime only, C. atrata showed a tendency of singing when the nighttime temperature was high ($24-30^{\circ}C$, average $27^{\circ}C$), whereas H. fuscata did not show a correlation with meteorological factors. However, since H. fuscata sang during the night in areas with artificial lighting, it was concluded that its singing was due to light pollution.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.149-157
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• 2003

This study focused on relationships between Pb and Cd concentrations and the difference of success reproductive progress in urban (Seoul) and industrial complex (Ansan) areas. Results of the Pb analysis for the feral pigeons from Seoul (egg contents:1.64 $\mu\textrm{g}$ wet $g^{-1}$, adults in bones: 29.5 $\mu\textrm{g}$ wet $g^{-1}$ and the Ansan industrial complex (egg contents: 1.13 $\mu\textrm{g}$ wet $g^{-1}$, adults in bones: 10.5 $\mu\textrm{g}$ wet g-1) showed that the Pb level of eggs and adults is significantly different between the two colonies (p<0.05). Cd concentrations in liver and kidneys of adult pigeons were also significantly different between Seoul(liver: 0.24 ${\mu}g$ wet $g^{-1}$, kidney: 1.05 $\mu\textrm{g}$ wet $g^{-1}$ and the Ansan (liver: 0.14 $\mu\textrm{g}$ wet $g^{-1}$, kidney: 0.43 $\mu\textrm{g}$ wet $g^{-1}$ colonies (P<0.05). Clutch size of Feral Pigeons living in Seoul was similar between the two colonies, 1.9$\pm$0.3 in Seoul and 2.0$\pm$0.0 in Ansan. The length, breadth, and thickness of eggs were not significantly different between the two colonies (p>0.05). Incubation period in Seoul (17.8 days) did not differ from the Ansan (17.4 days). No difference in growth rate (body weight, wing length, and tarsus length) was found between the two test groups (p>0.05). In Seoul, 65.2% were hatching, and 42.1% fledging. The Proportion of hatching and fledging in the Ansan was 60.7% and 45.0%, respectively. The significant differences between the two colonies for reproductive sucess were not found (p>0.05). With regard to the reproductive effects to the heavy metals, the Pb and Cd concentrations feund in the two colonies were not as high as those considered in results of toxic effects in other species.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.88-100
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• 2014

The purpose of the study is to analyze the regional effectiveness of wall-plantings by applying a biotope area ratio when wall-plantings are constructed in high density areas. For this, this study required a sample of the wall-planting's regional plan. Therefore, types of wall-planting were determined and applied to a sample site. Four types of wall-plantings were developed by formative features and functional features. Type "A" had simple and functional features, Type "B" had both mixed and functional features, Type "C" had both simple and landscape features and Type "D" had mixed and landscape features. Jung-gu District in Seoul was chosen as the sample site. Total investigations were performed three times for three months from June to August, 2011. Total green-able walls were located in 498 places with a total length of 8,449m and gross vertical area of $23,754.90m^2$. The classification results of total green-able walls by the four types were Type "A" at $1,936.65m^2$, Type "B" at $5,875.30m^2$, Type "C" at $12,487.85m^2$ and Type "D" at $3,455.10m^2$. This study analyzed how all facade areas of the green-able walls impacted the biotope area ratio at the site. First, the biotope area ratio regarding all the zones in Jung-gu District was defined as the gross biotope area ratio while the biotope area ratio regarding all of the artificial zones was defined as the net biotope area ratio. In the case of the gross biotope area ratio, 17.97% is current ration with a projected increase to 0.10% after wall-planting. In the case of the net biotope area ratio, 4.73% is the current ration with a projected increase to 0.11% after wall-planting. This 0.11% is about 2.28% of 4.73%. This study looks at all wall-plantings that have been constructed throughout a high density area to observe their impact on the improvement of ecological function therein. With consideration of the landscape value of the facade, the regional effectiveness of wall-planting is expected to increase even more.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.279-286
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• 1991

This study was carried out to investigate relationships between atmospheric $SO_2$ concentration and both soluble sulphur contents in the tree leaves and bark pH to test the possibility of using them as bioindicators for air pollution. Mt. Kwanak, Mt. Nam, Mt. Bukhan (located in Seoul) and Mt. Paldal (located in Suwon, Kyonggi-do) as polluted areas and Pyongchang, Kwangwon-do as an unpolluted area were selected for this study. Soluble sulphur contents in the leaves and hark pH of two tree species (Pines densiflora S. et Z. and Quercus mongolica Fisch.) were analyzed in May, August, and October, 1990 by $BaSO_4$ precipitation method and pH measurement, respectively. In both species, concentration of soluble sulphur in the leaves increased with increasing concentration of atmospheric $SO_2$ (correlation coefficient : 0.52). Soluble sulphur contents in the 2-year-old needles of Pines densiflora (0.170%) and current year leaves of Quercus mongolica (0.081%) in Mt. Nam in the center of Seoul were higher than those in unpolluted Pyongchang area (0.023% and 0.034%, respectively). Bark pH decreased with increasing atmospheric $SO_2$ concentration (correlation coefficient : -0.52). Bark pH of P. densiflora (pH 3.42) and Q. mongolica (pH 3.63) in Mt. Nam were lower than those in Pyongchang area (pH 3.94 and pH 4.93, respectively). Both soluble S content in the leaves and bark pH were recognized as suitable bioindicators for air pollution by $SO_2$. Especially, bark pH showed more sensitive response to air pollution by $SO_2$ than soluble S concentration in the leaves. The lowest concentration of soluble sulphur and the highest bark pH in August were considered to be due to heavy rain during the rainy season. Soluble S content in the leaves and bark pH were not significantly different at 5% level between the two species in polluted areas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.2
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• pp.107-117
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• 2004

If doubtlessly contributes much to agriculture and rural development. The roles can be summarized as; 1. to activate rural areas and to provide more comfortable and safe rural life with equivalent services to those in urban areas, facilitating distance education, tole-medicine, remote public services, remote entertainment etc. 2. To initiate new agricultural and rural business such as e-commerce, real estate business for satellite officies, rural tourism and virtual corporation of small-scale farms. 3. To support policy-making and evaluation on optimal farm production, disaster management, effective agro-environmental resource management etc., providing tools such as GIS. 4. To improve farm management and farming technologies by efficient farm management, risk management, effective information or knowledge transfer etc., realizing competitive and sustainable farming with safe products. 5. To provide systems and tools to secure food traceability and reliability that has been an emerging issue concerning farm products since serious contamination such as BSE and chicken flu was detected. 6. To take an important and key role for industrialization of farming or lam business enterprise, combining the above roles.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.57-69
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• 2014

As of 2013, Korean population density is 505 persons per $1km^2$ and is ranked 3rd place in the most densely populated countries exception of city-states. It shows clearly the population is concentrated in the city area. To fulfil this urban concentration population demand, the enlargement and complexation of buildings, subway and other underground spaces connection tendency has been intensified, and it is need to construct the indoor spatial information DB as well as the accurate indoor surveying DB to promote people's safety and social welfare. In this study, Sadang station and Incheon National Airport were aimed for the construction of Wi-Fi AP location DB and RadioMap DB by collecting the indoor AP raw datas by using mobile device and those collected results were ran through the process of verification, supplementation, and analyzation. To evaluate the performance of constructed DB, 10 points in Incheon Airport- 3rd flr in block A, and 9 points in Sadang station-B1 were selected and calculated the estimated points and ran evaluation experiment using survey positioning error, which is distance between real position and the estimated position. The result shows that Incheon international airport's average and standard deviation was separately 17.81m, 17.79m and Sadang station's average and standard deviation was separately 22.64m, 23.74m. In Sadang station's case, the areas near the exit has low performance of surveying position due to fewer visible AP points than other areas. As total datas were examined except those position, it was verified that the user's location was mapping close position in surveying positioning by using constructed DB. It means that constructed DB contains correct Wi-Fi AP locations and radio wave patterns in object region, so it is considered that the indoor spatial information service based on constructed DB would be available.

• International Commerce and Information Review
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• v.15 no.4
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• pp.457-479
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• 2013

Through a Chinese rise, Chinese dream is actualizing as the world's great power. According to outlook of World Bank and IMF, Around 2030 China will be a great power bigger than America's economic power. The rise of China will give a huge impact to the whole world. China expands her influence through a global manufacturing base and a global market. To actualize 'Peaceful Rise' Strategy, China has many constraints. Chinese society is facing many difficult social problem due to side effects of a rapid development. Such as the spread of corruption, the severity of wealth gap, environmental degradation and energy shortage. Internationally there are containment from hegemon so-called 'China threat' dispute, Taiwan issue and territorial disputes. Western countries are hostile to China for two reasons. Based on expectations, one is China's socialist system and the other is the rising China which will compete for supremacy with Europe and America. Recent emergence of Chinese nationalism and the containment of the neighboring countries are also serious limiting factors. Domestically they have the rampant corruption in the bureaucracy, weakened capacity of Communist rule, wealth disparity due to the discriminatory economic development strategy, seriousness of rural problem, social instability, lack of social security systems and the development gap between the eastern coastal areas and western inland areas, ethnic minorities problems, the constraint of sustainable development issues due to lack of resources, environmental pollution and energy constraints. Like the former Soviet Union, China may face a dismantlement. After the rise, China may encounter possibilities of a war between great powers or a collapse of Chinese society caused by deepening internal conflict. Serious economic polarization would make peasants and urban workers, who are social vulnerable people, to turn their back to communist party and threaten the justification and the appropriateness of the ruling communist party. Chinese government will think internal system security threat is more formidable risk factor than a system security threat from the hegemon. The decline of great country comes from internal reasons rather than external reasons. To achieve peaceful rise, unification with Taiwan is an essential prerequisite. Taiwan issues are complex problems which equipped with international and domestic factors. Lack of energy resources, environmental pollution in China will bring economic crisis to Korean enterprises. Important influence to Korean economy will be a changeover of the method in economic development. It will turn the balance of investment and consumption, GDP-centered growth to consumption and environment-centered growth. Services industries including finance, environment, culture, education, health care and social welfare will grow. Change in China's growth model will give a great challenge upon the intermediate goods industry in Korea. Korea should reduce the portion of machinery, automotive, semiconductor, steel and chemical-centered export industry to China, and should increase the proportion of the service industry.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.37-49
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• 2015

The goal of this research is to examine air temperature changes according to tree type, plantation type, roadside green area structure, and green volume of street green area within a city. The plantation type that could be analyzed for comparison by tree type with over 3 species was 1 rows of tree+shrubs. The results of analysis of average air temperature difference between pedestrian and car streets vis-a-vis 1 row of tree+shrub in high air temperature areas were: Pinus densiflora, $1.35^{\circ}C$; Zelkova serrata, $1.84^{\circ}C$; Ginkgo biloba, $2.00^{\circ}C$; Platanus occidentalis, $2.57^{\circ}C$. This standard large wide canopy species was analyzed by the roadside to provide shade to have a significant impact on air temperature reduction. In terms of analysis of the relationship between plantation type of roadside trees and air temperature, the average air temperature difference for 1 row of tree type was $1.80^{\circ}C$; for 2 rows of trees it was $2.15^{\circ}C$. In terms of analysis of the relationship between the roadside green area structure and air temperature, for tree type, average air temperature $1.94^{\circ}C$: for tree+shrub type, average air temperature $2.49^{\circ}C$; for tree+mid-size tree+shrub type, average air temperature $2.57^{\circ}C$. That is, air temperature reduction was more effective in a multi-layer structure than a single layer structure. In the relationship analysis of green volume and air temperature reduction, the air temperature reduction effect was enlarged as there was a large amount of green volume. There was a relationship with the green volume of the road, the size of the tree and number of tree layers and a multi-layer structured form of planting. The canopy volume was large and there were a great number of rows of the tree layer and the plantation type of multi-layer structure, which is what is meant through a relationship with the green volume along the roadside. Green composition standards for air temperature reduction effects and functional improvement were proposed based on the result. For a pedestrian street width of 3m or less in the field being ideal, deciduous broadleaf trees in which the canopy volume is small and the structure of the tree+shrub type through the greatest 1m green bend were proposed. For a pedestrian street width of over 3m, deciduous broadleaf trees in which the canopy volume is large and is multi-layer planted with green bend over 1m, tree+mid-size tree+shrub type was proposed.