• Wind and Structures
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• v.9 no.1
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• pp.23-35
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• 2006

The effect of buildings on flow in urban canopy is one of the most important problems in local/micro-scale meteorology. A large eddy simulation model is used to simulate the flow structure in an urban neighborhood and the bulk effect of the buildings on surrounding flows is analyzed. The results demonstrate that: (a) The inflow conditions affect the detailed flow characteristics much in the building group, including: the distortion or disappearance of the wake vortexes, the change of funneling effect area and the change of location, size of the static-wind area. (b) The bulk effect of the buildings leads to a loss of wind speed in the low layer where height is less than four times of the average building height, and this loss effect changes little when the inflow direction changes. (c) In the bulk effect to environmental fields, the change of inflow direction affects the vertical distribution of turbulence greatly. The peak value of the turbulence energy appears at the height of the average building height. The attribution of fluctuations of different components to turbulence changes greatly at different height levels, in the low levels the horizontal speed fluctuation attribute mostly, while the vertical speed fluctuation does in high levels.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1486-1492
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• 2015

The following study carried out the characteristic analysis based on the magnet segment of Interior Permanent Magnet Synchronous Motor(IPMSM) for the urban railway vehicles. IPMSM affects the electromagnetic characteristics through the change in magnetic flux based on the rotor structure, and significantly influences the structural features through the change of pressure. Therefore, satisfied by the demanded traction force of the IPMSM, magnet segment derived three different model types. The 1-segment PM model consisted an undivided permanent magnet. The 2-Bridge model consisted a divided permanent magnet with the application of Bridge. The 3-Bridge model consisted additional dividing with one more Bridge applied. The electromagnetic characteristics of the three models were compared and analyzed along with the structural features regarding the scattering of permanent magnet based on strong centrifugal force from the rotation of the rotor at high speed. In conclusion, the final model with electromagnetic characteristics and structural features most suitable of IPMSM for the urban railway vehicles was derived, and the effectiveness was verified through the characteristic experiments after the production of the derived model.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.59-66
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• 2001

The tremendous growth of population and physical development in the largest urban agglomeration in Indonesia -the Jakarta Metropolitan Region, also known as Jabotabek (Jakarta, Bogor, Tanggerang, Bekasi)- has created many environmental problems, such as land use conversion, increasing urban temperature, water and air pollution, intrusion of seawater, and flooding. These problems have become more serious as the urban green space (trees, shrubs, and groundcovers) has decreased rapidly with the urbanization process. Urban green space directly benefits the urban environment through ameliorating air pollution, controlling temperature, contributing to the balance of the hydrological system, and providing space for recreation and relaxation. Because there is little hard data to support the claim of decreasing greenery in Jabotabek, it is necessary to measure the amount of urban green space. The paper describes the spatial analysis of urban green space within Jabotabek through the use of a geographical information system (GIS). We used GIS and remote sensing to determine land cover change and predicted greenery percentage. Interpretation of Landsat data for 1972, 1983, 1990, and 1997 showed that Jabotabek has experiences rapid development and associated depletion of green open space. The proportion of green open space fell by 23% from 1972 to 1997. We found a low percentage of urban green space in the center of Jakarta but a high percentage in fringe area. The amount of greenery is predicted by the Ratio Vegetation Index (RVI) model: predicted greenery (%) = [146.04] RVI - 134.96. We consider that our result will be useful for landscape planning to improve the environment of Jabotabek.

• Journal of Forest and Environmental Science
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• v.28 no.1
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• pp.46-55
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• 2012

The research on urban forests in Chuncheon, so far, has mainly conducted in Ponguisan urban forest. Research on other urban forests in Chuncheon was scarce. Accordingly, in this study, the author chose the main urban forests in Chuncheon and tried to find a way of efficient establishment and management of urban forests in Chuncheon by field and questionnaire survey. The research findings, there were several reasons why effective management can not be implemented in the main urban forests in Chuncheon. To solve these problems and make an efficient establishment and management of urban forests in Chuncheon, the first way is to make forest management plans on the urban forest in Chuncheon and expand administrative organization, personnel and budget. Establishment and management of urban forests needs a practical, strengthened overall management system. The second way is to enhance the regional and functional characteristics for urban forest, expand the area of urban forests, and enhance management of Street trees. The third way is to designate Urban Nature Park or Urban Park for the main urban forests in Chuncheon and need to change the ownership of the urban forests by purchasing. The fourth way is to respond to Chuncheon citizen's preference and their way of utilization when create the urban forests in Chuncheon, expand convenience facilities, relaxation facilities as well.

• Journal of the Korean association of regional geographers
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• v.23 no.1
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• pp.136-150
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• 2017

This study analyzed the spatial change of urban green spaces in Daegu from 1989 to 2009 using cell based spatial metrics. To do so, the conversion process of land covers during the past 20 years was explored using a land cover change detection matrix. The synoptic analysis with a moving window sampling strategy was conducted to quantify cell based spatial metrics related to size, shape, cohesion, and diversity and to explain the spatial change at the local level. Difference maps were then generated by subtracting the 1989 maps of spatial metrics from the 1998 maps and the 1998 maps from the 2009 maps. The gradient analysis was performed to identify the directional change of spatial metrics along an urban development axis in Daegu. The results from this study show that urban green spaces in Daegu during the past 20 years have been gradually fragmented around the new town housing development districts such as Dalseong-gun, Seongseo, and Ansim. Forests were most prominently fragmented in the Hwawon area while most rapidly in the Chilgok area. Grasslands were largely fragmented in many areas due to the decrease in size and cohesion indices and most fragmented in the Ansim area. The spatial pattern of the decreased and fragmented urban green spaces identified by this study can be used as a base data for establishing the environment-friendly urban development strategy in Daegu.

• Journal of KIBIM
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• v.7 no.2
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• pp.36-43
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• 2017

Population growth and rapid urbanization has been converting large amounts of rural vegetation into urbanized areas. This human induced change has increased temperature in urban areas in comparison to adjacent rural regions. Various studies regarding to urban heat island have been conducted in different disciplines in order to analyze the environmental issue. Especially, different types of thermal infrared remote sensing data are applied to urban heat island research. This article reviews research focusing on thermal infrared remote sensing for urban heat island and urban planning studies. Seven studies of analyses for the relationships between urban heat island and other dependent indicators in urban planning discipline are reviewed. Despite of different types of thermal infrared remote sensing data, units of analysis, land use and land cover, and other dependent variable, each study results in meaningful outputs which can be implemented in urban planning strategies. As the application of thermal infrared remote sensing data is critical to measure urban heat island, it is important to understand its advantages and disadvantages for better analyses of urban heat island based on this review. Despite of its limitations - spatial resolution, overpass time, and revisiting cycle, it is meaningful to conduct future research on urban heat island with thermal infrared remote sensing data as well as its application to urban planning disciplines. Based on the results from this review, future research with remotely sensed data of urban heat island and urban planning could be modified and better results and mitigation strategies could be developed.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.246-248
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• 2018

Urban development and population have augmented the increase of impervious land-cover. This phenomenon has amplified the effects of climate change and increasing urban island effects due to increases in urban temperatures. Seoul, South Korea is one of the largest metropolitan cities in the world. While land uses in Seoul vary, land cover patterns have not changed much (under 2%) in the past 10 years, making the city a prime target for studying the effects of land cover types on the urban temperature. This research seeks to generalize the urban temperature of Seoul through a series of statistical tests using multi-temporal remote sensing data focusing on multiple scales and typologies of green space to determine its overall effectiveness in reducing the urban heat. The distribution of LST values was reduced as the size of urban forests increased. It means that changing temperature of large-scale green-spaces is less influenced because the broad distribution could be resulted in various external variables such as slope aspect, topographic height and density of planting areas, while small-scale urban forests are more affected from that. The large-scale green spaces contributed significantly to lowering urban temperature by showing a similar mean LST value. Both of concentration and dispersal of urban forests affected the reduction of urban temperature. Therefore, the findings of this research support that creating urban forests in an urban region could reduce urban temperature regardless of the scale.

• Journal of East-Asian Urban History
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• v.1
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• pp.25-54
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• 2019

Kyoto, which was Japan's political and cultural capital for more than a millennium before the dawn of the modern era, shows distinctive characteristics formed in the process of urban modernization. A citizen plaza perfectly fit to a modern city is lying on the east side, but a delayed urban reconstruction in the city center due to a strong conservative self-government awareness, as well as a delayed modernization of tax system, caused disorderly urban sprawl to appear in the suburbs. Thanks to the enactment of urban planning law enacted in 1919 by the government (Ministry of Internal Affairs) and an increasing awareness about the necessity and rationality of urban planning projects, urban renovation took place at a rapid pace. In the meantime, new ways of urban design were sought for and experimented to conserve it as a historical city against the city' quickly changing landscape.

• Architectural research
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• v.23 no.2
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• pp.29-37
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• 2021

Early in the communist era, many cities in modern China experienced a special period of passive industrialization during which the construction of urban spaces laid the spatial urban foundation. During this period, the city construction was carried out rapidly under the administrative intervention of the government. The passive industrialization caused by taking economic construction as the center made the city construction deviate from the correct track and resulted in a variety of problems. Focusing on ecological space change, this paper selects Zhengzhou as an example of many similar cities in China, and analyzes the impact of passive industrialization on urban ecological spaces from the perspectives of city scale, city layout and city construction management system. The analysis results reveal that the construction of urban ecological space under the influence of passive industrialization induced a lagging characteristic, led to insufficient integrity of urban ecological space, and placed great pressure on the urban environment. Finally, the paper puts forward some methods to optimize the urban ecological space.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.296-304
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• 2015

The rapid increase in the number of climate disasters combined with the scale of change and the diversification of natural disasters require a radical solution. In particular, the urban space is more complex, therefore we need to establish measures for disaster response and how to react to damaged infrastructure based on the phenomenon of an increase in the urban population and the impermeable layer being extended. The social problems related to the economic burden of land purchase and the securing of a disaster prevention system can be solved simultaneously by introducing the park system for disaster reduction into the public land of the green space in the city. The local government has recently adapted diverse systems of disaster mitigation and carried out pioneer projects according to the guidelines for the construction of the urban park for disaster prevention published by the Ministry of Land, Infrastructure and Transport. The purpose of this study is to propose a composition model for neighborhood parks to prevent disaster through urban green spaces which has the functions of water management and biotope conservation. The result of this study will contribute to utilize the climate change adaptation model for living area neighborhood parks in the existing urban structure.