• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.4
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• pp.61-75
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• 2018

This study aims to verify the effect of green buffers, built as urban planning facilities on the reduction of ultra-fine particulate($PM_{2.5}$) and analyze changes in ultra-fine particles by structure, green volume and planting types of wayside green buffers, thus drawing the factors that can be used when green buffers are built to reduce ultra-fine particulate based on the results. This study selected Songpa-gu, and investigated 16 sites on 5 green buffers adjacent to two of Songpa-gu's main roads, 'Yangjaedaero' and 'Songpadaero'. This study divided all the green spaces into three different types-slope type, plain type and mounding type, and analyzed the mean green volume. As a result of measuring the concentration of $PM_{2.5}$, this study found that it was $55.5{\mu}g/m^3$ on average in winter, which was a harmful level according to the integrated environmental index provided by Seoul City, saying that levels above $50{\mu}g/m^3$ may have a harmful effect on sensitive groups of people. Particularly, the concentration of $PM_{2.5}$ was $38.6{\mu}g/m^3$ on average in spring, which exceeded the mean concentration of $PM_{2.5}$ in Seoul City in 2015. The mean concentrations of $PM_{2.5}$ in every investigation spot were $46.6{\mu}g/m^3$ for sidewalks, $45.5{\mu}g/m^3$ for green spaces and $42.9{\mu}g/m^3$ for residential areas, all of which were lower than $53.2{\mu}g/m^3$ for roads, regardless of the season. The concentration of $PM_{2.5}$ for residential areas was the lowest. In the stage of confirming the effect of green buffers, this study analyzed the correlation between the green volume of vegetation and the fluctuated rate of ultra-fine particles. As a result, it was found that the green coverage rate of trees and shrubs was related to the crown volume in every investigation spot but were mutually and complexly affected by each other. Therefore, this study judged that the greater the number of layers of shrubs that are made, the more effective it is in reducing the concentration of $PM_{2.5}$. As for seasonal characteristics, this study analyzed the correlation between the concentration of $PM_{2.5}$ for residential areas in winter and the green coverage rate of each green space type. As a result, this study found that there was a negative correlation showing that the higher the shrub green coverage rate is, the lower the concentration value becomes in all the slope-type, plain-type and mounding-type green spaces. This study confirmed that the number of tree rows and the number of shrub layers have negative correlations with the fluctuated concentration rate of $PM_{2.5}$. Especially, it was judged that the shrub green volume has greater effect than any other factor, and each green space type shows a negative correlation with the shrub coverage rate in winter.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.1
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• pp.42-53
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• 2021

Street trees improve the cityscape and air quality, reduce heat islands, and create wildlife habitats. Hence, they are essential parts of a city's green infrastructure. Therefore, several trees that are well adapted to the urban environment were planted. However, this caused the problem of simple trees being planted around the world. This study is to select more various street trees. To accomplish this, evaluation criteria and detailed indexes were created. The importance was indicated through the Analytic Hierarchy Process. For commercial roads, the priority of landscape characteristics is 0.2640, and among detailed indicators, the priority of shape is 0.1245. For work roads, the priority of landscape characteristics is 0.2496, and among detailed indicators, the priority of shape is 0.1177. For work roads, the priority of characteristics of civil service is 0.2250, and among detailed indicators, the priority of shape is 0.1177. For general roads, the priority of maintenance characteristics is 0.2479, and among detailed indicators, the priority of shape is 0.1062. For historical and cultural roads, the priority of regional characteristics is 0.3488, and among detailed indicators, the priority of regional characteristics is 0.1643. For ecological roads, the priority of ecosystem characteristics is 0.3488, and among detailed indicators, the priority of the diversity of species is 0.1643. For automotive-only roads, the priority of the ecosystem characteristics is 0.4639, and among detailed indicators, the priority of reducing emissions is 0.1643. This study will provide objective criteria for the selection of street trees.

• Journal of Environmental Science International
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• v.26 no.12
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• pp.1363-1374
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• 2017

Global climate change caused by industrialization has caused abnormal weather conditions such as urban temperatures and tropical nights, urban heat waves, heat waves, and heavy rains. Therefore, the study tried to analyze climate conditions and weather conditions in the streets and analyze climate factors and meteorological factors that lead to inconvenience to citizens. In the case of trees, the overall temperature, surface temperature, solar irradiance, and net radiation were measured low, and the temperature was lower in the Pedestrian road than in roads. The dry bulb temperature, the black bulb temperature, and the wet bulb temperature for the thermal evaluation showed the same tendency. In the case of thermal evaluation, there was a similar tendency to temperature in WBGT, MRT, and UTCI, and varied differences between types. Although the correlation between the meteorological environment and the thermal environment showed a statistically significant significance, the difference between the measured items was not significant. The study found that the trees were generally pleasant to weather and thermal climate in the form of trees, and the differences were mostly documented.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.49-60
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• 2008

In this study, the green zone patterns of sidewalks are classified 'one street-tree row + building,' 'one street-tree row + green zone,' 'two street-tree rows + building,' and 'two street-tree rows + green zone' and assessed their visual characteristic in order to provide desirable measures for scenery design. As a result of the analysis of visual images of sidewalk, the scenery in which street trees are planted in one row was generally assessed to be negative, while roads where green zones rather than buildings are adjacent were revealed to seem stable and pleasant. The scenery in which street trees are planted in two rows was assessed highly in an image of 'extensionality' indicating street circumstances, and especially the pattern 'two street-tree rows + green zone' was shown to be the most beautiful scenery. According to the results of factor analysis of sidewalks, three factors were identified : 'extensionality' showing sidewalk circumstances; 'peculiarity' including unique personality, and 'pliability' showing the organic flow of the scenery. The results of the analysis of visual preference of the scenery according to green zone patterns showed that the 'two street-tree rows + green zone' was measured to be highest. When buildings are adjacent to a sidewalk, two street-tree rows rather than one street-tree row were assessed to increase preference. As for the correlation between visual factors and preference analyzed through multiple regression analysis, all 'extensionality,' 'peculiarity,' and 'pliability' were revealed to show positive correlation for visual preference.

• Journal of the Korean association of regional geographers
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• v.23 no.2
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• pp.403-419
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• 2017

This study analyzed the forces to drive the change of urban green spaces in Daegu from 1989 to 2009. First, the loss and fragmentation of green spaces in the past 20 years were spatially identified by performing the hot spots analysis for the cell-based spatial metrics quantifying the size and diversity of green spaces. Next, seven drivers such as slope, distance to roads, land price, population density, ratios of residential, commercial, and industrial areas were selected based on the previous studies and the direction of the association between the loss and fragmentation of green spaces and seven drivers was analyzed with the stepwise logistic regression. Finally, the relative importance of the seven drivers and their interactions in the past 20 years were analyzed with the geographical detector. The results show that the loss of green spaces was concentrated on a part of the Anshim housing development district from 1989 to 2009 and green spaces were highly fragmented around the housing development districts such as Seongseo, Anshim, Dalseong-gun and Chilgok. The forces to drive the loss and fragmentation of green spaces in these areas were different at the administrative levels, but the drivers such as slope and ratios of residential and industrial areas were commonly significant. These drivers were positively correlated with largest patch index(LPI) quantifying the loss of green spaces while they were negatively correlated with Shannon's diversity index(SHDI) measuring the fragmentation of green spaces. In other words, the loss and fragmentation of urban green spaces in Daegu appeared around such regions with lower slope and lower ratios of residential and industrial areas. The relative importance of drivers for LPI was listed as ratio of industrial area, land price, and ratio of commercial area in descending order whereas that of drivers for SHDI was listed as ratio of industrial area, land price, and distance to roads in descending order. Also, the interaction between slope and ratio of residential area had a great impact on LPI and SHDI. The ratio of industrial area was a single driver to most significantly explain the loss and fragmentation of urban green spaces in Daegu in the past 20 years. The interaction between slope and ratio of residential area was greater than the independent influence of a single driver. This study will provide the base data to build a sustainable urban green policy for the city of Daegu in the near future.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.57-65
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• 2011

In this study, estimated the minimum lane width for the curved section by analyzing of lateral sway distance and compared the lane width for result of this study and a precedent study for straight section on urban roads. Then suggested minimum lane width of road alignments and vehicle classes. The lane width of curved section that was investigated was 2.79m~3.40m. Analysis of frequency distribute and cumulative frequency distribution for lateral sway distance on the basis of 85% of the suggested vehicles. The result of study, minimum lane width for the curved section was 2.31m~2.58m in the case of small size car and 2.80m~3.27m in the case of large size car. Result of this study is judged that it is necessary to case for introduction of green transit, during road construction and construct a road for small size car. Expect result of this study can be used for the application of flexible design standard according the purpose of road designer.

• Journal of Korea Planning Association
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• v.53 no.7
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• pp.109-126
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• 2018

The purpose of this study is to identify the spatial types for thermal environment improvement considering heat flux and its spatial context through empirical orthodox formulas. First, k-means clustering was used to classify values of three kinds of heat flux - latent, sensible and storage heat. Next, from the k-means clustering, we defined a type of thermal environment (type LHL) where improvement is needed for more comfortable and pleasant thermal environment in the city, among the eight types. Lastly, we compared and analyzed the characteristics of each classified thermal environmental types based on land cover types. From the study, we found that the ratio of impervious surfaces, roads, and buildings of the type LHL is higher than those of the type HLH (relatively thermal comfort environment). In order to improve the thermal environment, the following contents are proposed to urban planners and designers depending on the results of the study. a) Increase the green zone rate by 10% to reduce sensible heat; b) Reduce the percentage of impermeable surfaces and roads by 10% ; c) Latent heat increases when water and green spaces are expanded. This study will help to establish a minimum criterion for a land cover rate for the improvement of the urban thermal environment and a standard index for the thermal environmental improvement can be derived.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.241-247
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• 2016

As a domestic traffic control signal system, either the system with which a traffic signal turns into green at regular intervals or the system with which an amber or a red signal flickers on local roads without heavy traffic at midnight has been utilized. However, when the former system is used for roads with light traffic at midnight, delays and congestion can be incurred. Besides, in case of the latter signal system, the risk of vehicle crash is high. This study proposes a response type of flickering green signal system that rearranges signal system after analyzing beacon messages including sensor data. The proposed system, on a trunk road or a branch road at midnight, makes the signal keep flickering in green; When a vehicle enters the range of RSE, the transfer coverage, it transmits beacon messages regularly and Agent System analyzes the messages and alters the signal. It is a system by which vehicles move following the altered signal system, which will not only ensure smooth flow but also prevent vehicles from crashing on a road with light traffic. As a result of a simulation, traffic throughput and the average waiting time displayed 10 to 30 percent better improvement than existing signal systems, in terms of performance.

• Korean Institute of Interior Design Journal
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• v.23 no.3
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• pp.231-238
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• 2014

Recently, many people can experience the virtual space by smartphone, and they use many games. In particular, this change has great implications in the collaborative and communicative planning paradigm, which is residents' participation and agreement becoming important in community making and urban design. This study analyze the case of the five virtual space games about community making and urban design, and examine the related regal system. Game users can construct roads, houses, buildings and facilities in the virtual city. Then, they create profit, and promote the growth of virtual city. In these games, construction elements are classified residential, commercial, industrial, parks, green spaces, public building, and roads. But these elements does not identified clearly, and they mixed. By analyzing of related regal system, these games focus on the individual buildings, spaces, and facilities rather than considering the terms of urban planning. To complement the virtual space game with the aspects of urban planning, these games can encourage the participation capability and enhance the communication skills of citizens.

• International Journal of Highway Engineering
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• v.19 no.4
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• pp.69-78
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• 2017

PURPOSES : In this study, we analyzed the road crossing behavior of older pedestrians on a mid-block signalized crosswalk, and compared it to that of younger pedestrians. In addition, we analyzed the correlation between accidents involving older pedestrians while crossing roads and their behavioral characteristics. Finally, we confirmed the reasons for an increase in accidents involving older pedestrians. METHODS : First, 30 areas with the highest incidence of accidents involving older pedestrians while crossing roads were selected as target areas for analysis. Next, we measured the start-up delay (the time elapsed from the moment the signal turns green to the moment the pedestrian starts walking) and head movement (the number of head turns during crossing a road) of 900 (450 older and 450 younger) pedestrians. The next step was to conduct a survey and confirm the differences in judgment between older and younger pedestrians about approaching vehicles. Finally, we analyzed the correlation between the survey results and traffic accidents. RESULTS : The average start-up delay and head movement of the older pedestrians was 1.58 seconds and 3.15 times, respectively. A definite correlation was obtained between head movement and the frequency of pedestrian traffic accidents. The results of our survey indicate that 17.3% of the older pedestrians and 7.8% of the younger pedestrians have a high crash risk. CONCLUSIONS : Behavioral characteristics of older pedestrians were closely correlated with accidents involving older pedestrians while crossing roads in mid-block signalized crosswalks. Our study indicates that in order to reduce the number of accidents involving older pedestrians, it is necessary to develop an improvement plan including measures such as installation of safety facilities taking the behavioral characteristics of older pedestrians into consideration and their safety education.