• Journal of Environmental Science International
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• v.14 no.3
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• pp.271-278
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• 2005

This study analyzes the recognition of commercial business men and employers who operate the commercial zone along the streets in the downtown area on the planting for the roadside green space forming the important frame of greening in the downtown among the open spaces. Through the analysis, this study attempts to get the basic data to suggest the recommendable directions in planting and managing the street trees in the downtown. The results of this study are summarized as described below. The street green spaces are very important in improving the environment of the downtown and their necessities are also very critical. It was found that the street trees were recognized as the critical factor to enhance the aesthetical values of the city, provide the green shades and purify the air. This study also identified that the street trees have the positive impacts on the business environment rather than negative impacts. In maintaining the street green spaces, the most necessity is the service facility such as resting areas, toilets and garbage bins with the street trees. The commercial business men and employers who operate the businesses along the streets preferred the double layer type that the tall trees and green walls are planted together along the streets for the street planting. For securing the green shades in the city, the planting of linear green spaces such as streets and waterways is critical. Moreover, the street trees accounts for the important position in the urban open spaces. The majority of commercial business men and employers consider the participation of citizens for greening as the very essential factor.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.63-73
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• 2016

PURPOSES : The objective of this study was to analyze variations in the vehicle driving behavior characteristics on signalized intersections according to the use of traffic enforcement camera (red light camera). METHODS : In order to analyze the driving behavior characteristics on signalized intersections when red light camera are installed, the target sites for investigation were selected depending on whether the red light camera is installed and accident rates increased after the installation. In particular, to analyze the characteristics of dilemma zones in signalized intersections, approach speed and deceleration speed of 3 type vehicles (passing vehicles during a yellow light, stopping at a yellow light, passing vehicles during a green light) were examined. Based on these data, the starting point, ending point, and distance of the dilemma zones were calculated. Also, the locations of increased traffic accidents and decreased accidents after the installation of the equipment were distinguished when analyzing the traffic accident characteristics. RESULTS : Analysis results revealed that there was a tendency for the dilemma zone distance to decrease after the installation of equipment(red light camera) in most sites. This tendency was found to be due to the decrease in the approaching speed of vehicles at intersections after the installation of equipment, resulting in the starting and ending points of dilemma zone to become closer to the stop line. Moreover, analysis showed that the number of traffic accidents decreased for most intersections after the installation of equipment and safety of the intersections increased somewhat. CONCLUSIONS : In general, installation of equipment(red light camera) caused the intersections approaching speed and dilemma zone distance to decrease. Decision-making is difficult for drivers in the dilemma zone, so the decrease in the dilemma zone distance implies an improvement in traffic safety. Furthermore, the number of accidents within intersections significantly decreased after the equipment was installed, leading to the conclusion that installation of the equipment affected the decrease in traffic accidents.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.45-58
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• 2006

This study was aimed to propose the plan of creating a biotope reflecting an ecological education as well as its function as the habitats of amphibian in Namsan Urban Natural Park in Seoul. There were Cheonil mineral spring area which was located on the southern side of Namsan, wetlands which was already created on the east valley(800$m^2$) and a buffer area of the circumference(1,100$m^2$) as the biotope sites. Major fields of this study include a survey of the staus, a basic plan, a master plan; a survey of this site was focused on topography, water system, existing vegetation, wildbird, amphibian, trail; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 8 types; Pinus densiflora forest, Pinus densiflora planted area, Prunus sargentii-Quercus spp. forest, Pinus rigida forest, Robinia pseudoacacia forest, artificial green space, wetlands, south beltway. There were Pinus densiflora planted area and Prunus sargentii-Quercus spp. forest as major vegetations of this site. 14 species and 33 individuals of wildbirds appeared, Rana temporaria ornativentris and Hynobius leechi were investigated in the wetlands.In particular, habitats of amphibian were divided eco-zone, buffer-zone and restore-zone, and habitats and facilities which would be suitable for the characteristics of each space were planned. As a result, environment elements of good habitats including spawn wetlands of amphibian, harbor of amphibian, water plant of wetland, wild shrubs forest, ecological landscape forest, wetland observation trail, fence of wetland protection and ramp by pebble and log were created at the site. The amphibian biotope of Namsan is rated high as an important space for conserving biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.3
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• pp.325-335
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• 1994

The spinel $MgO.Al_20_3$ single crystals were grown by FZ (floating zone) method. Its melting point is about, $2135^{\circ}C$ and is important to the process of the growth from the melt. There have been some reports of the growth by Czochralski and Verneuil method. However, this study is the first trial to the spinel crystal with the application of FZ method. In this study, $MgAl_2O_4$ spinel crystals were grown by using FZ method which uses the ellipsoidal mirror furnace having infrared halogen lamps as a heat source. With dopants of transition metal ions, it was possible to melt the feed rod which does not absorb the infrared rays due to the transparent properties to infrared ray of spinel itself and the red, green and blue colored spinel single crystals could be grown more easily. As a conclusion, the purpose of this study is to find the spinel single crystal growth mechanism with respect to th growth interfaces and molten zone stability and to characterize the state of growth resulting from the concavity to the melt of interfaces.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.48-61
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• 2020

The objective of this study is to estimate traffic capacity based on the heavy-vehicle ratio in a two-lane freeway work zone where one lane is blocked by construction. For this, closed circuit television (CCTV) video data of the freeway work zone was collected, and the congestion at an upstream point was observed. The traffic volume at a downstream point was analyzed after a bottleneck was created by the blockage due to the upstream congestion. A distribution model was estimated using observed-time headway, and the road capacity was analyzed using a goodness-of-fit test. Through this process, the general capacity and an equation for capacity based on the heavy-vehicle ratio passing through the work zone were presented. Capacity was estimated to be 1,181~1,422 passenger cars per hour per lane (pcphpl) at Yeongdong, and 1,475~1,589pcphpl at Jungbu Naeryuk. As the ratio of heavy vehicles increased, capacity gradually decreased. These findings can contribute to the proper capacity estimation and efficient traffic operation and management for two-lane freeway work zones that block one lane due to a work zone.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.37-46
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• 2002

The main purpose of this research is to discuss the urban heat island which will be caused by urbanization, especially by the construction of new town on a wide green zone. Over the last ten years, five new towns have been developed around the Seoul metropolitan area. However these new towns become bedroom communities and create traffic problems between Seoul and its surrounding areas because of an increase in population and a lack of roads and other infrastructures. The construction of another such new town is under consideration in the Pan-gyo area. But it is important that Pan-gyo remains a wide green zone. Many studies show that green space can play an important role in improving urban eco-meteorological, ameliorative capability and air hygiene. The objective of this study is to analyze the urban heat islands of Bund-Dang Si which was constructed in 1996 and of the Pan-Gyo area planned as new town. To investigate the local thermal environment and its negative effects caused by change of the land use type and urbanization we used LANDSAT TM images for extraction of urban surface temperature according to change of land use over 15 years. These data were analyzed together with digital land use and topographic data. As a study result, we found that the thermal island of this area from 1985 to 1999 rapidly increased with a difference of mean temperature of more than 12'E. Before construction of Bun-Dang Si the temperature of this area was the same as the forest, but during the new town construction in 1991, an urban heat island developed. The temperature of forest with a size of over 50% of the investigation area was lowest, which leads us to conclude that the forest cools the urban and its surroundings. The mean temperature of the residential and commercial area is more than +4.5$^{\circ}C$ higher then forest, so this method of land use is the main factor increasing the urban heat island. Urban heat islands and green space play an important role in urban wind systems, i.e. Thermal Induced Air Exchange and Structural Wind Circulation, because of their special properties with regard to energy balance between constructed urban and land. The skill to allocate land use types in urban areas is a very important planning device to reduce air pollution and induce the fresh cold air from green space. An urban climatic experiment featuring a numerical wind simulation study to show the air corridor will be published in a following research paper.

• KIEAE Journal
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• v.13 no.4
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• pp.33-41
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• 2013

The impervious area on the surface of urban area has been increased as buildings and artificial land cover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural ecosystem. There arise the environmental problems to urban area including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate flood discharge and heat reduction effect according to the green roof system and to quantify effect by analyzing through simulation water and heat cycle before and after green roof system. For the analysis, Distributed hydrologic model, WEP (Water and Energy transfer Processes) and WEP+ model were used. WEP was developed by Dr. Jia, the Public Works Research Institute in Japan (Jia et al., 2005), which can simulate water and heat cycle of an urban area with complex land uses including calculation of spatial and temporal distributions of water and heat cycle components. The WEP+ is a visualization and analysis system for the WEP model developed by Korea Institute of Construction Technology (KICT).

• Journal of Environmental Impact Assessment
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• v.8 no.3
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• pp.23-34
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• 1999

The purpose of this research is to establish a green space conservation grade for sustainable urban development of Taegu metropolitan city using GIS and RS methods, together with the valuation items of green spaces centered around ecological, useful, and socio-cultural factors. The results of this study are as follows: 1. According to the ecological factor, the first grade is $81.4km^2$ and then Kachag-myun, Dong-gu in order, have needs of sustaining conservation policy of urban environment improvement and protection of the wild habitats. 2. According to the usefulness of urban parks, the first and second grade which is over 150 $persons/km^2$ in population density of the catchment areas, were Talsung park, Sinam park, Yongsan park and etc., the areas of those parks consists of 0.7% of the whole urban parks. 3. According to the socio-cultural factor, the first grade is located in urban natural parks, and the second grade is which are composed of Green Belt and agriculture in Talsung-gun. 4. Analyzing these results synthetically, the first grade conservation is 18%, as the forest in the upper zone of Mt. Palgongsan, Mt. Bisul, and Mt. Daeduck, these regions needed to preserve absolutely. This research is a basic step to show the methodology for all-round evaluation of green space using GIS and RS. Hereafter, it is necessary to consider general evaluation index of green spaces, and to consider the quantitative and qualitative aspect.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.3
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• pp.1-18
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• 2021

England's green belt policy as it delivered its framework to designating the development restriction zones(DRZ) in Korea is the key to address issues which try to change green belt boundary or/and housing development. Therefore it should necessarily be reviewed on the understanding of how England has been formulating a national policy to deal with the issues focusing on opportunities for housing development and recreation. This study explored the discourse and framework of England's green belt policy as well as driver changes of housing development and recreation. Results show several characteristics of England's green belt policy which are civil society consensus on conservation and management, limited small-scale housing development through management of release rates, a systematic procedure for application and approval, open-recreation space expansion and utilisation under the premise of conservation of natural green areas, and management structure by the involvement of NGO organisations. Therefore, five suggestions can be delivered to developing Korea's DRZ frameworks: first, preceding social consensus on the preservation value of development-restricted zones, second, addressing housing shortages in different alternatives e.g.) environmental-friendly small-scale housing, third, institutionalising the total proportion of release, fourth, establishing an open-recreation space, fifth, introducing expanded public-private partnerships. Ultimately securing the legitimacy of the nation's development-restricted zone system can contribute positively to the environment preservation and human health by promoting public leisure activities in terms of the recent increase in external activities caused by the Covid-19 crisis. Concluding remarks are here that the understanding of England's green belt policy can be delivered to and help formulate domestic policy addressing current issues.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.4
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• pp.56-62
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• 1994

Far-zone electric fields radiated by a coaxial cable through an aperture in a perfectly conducting ground plane are calculated utilizing the dyadic Green's function and vector wave functions. In this paper the outer radius $\alpha$ is assumed to be less than 0.02 so that the aperture fields is well approximated by the dominant TEM mode in the coaxial cable. The result of present approach is compared with the readily obtained solution. The present solution is valid outside of the spherical regions with radius `$\alpha$' from the center of coaxial cable.