• Journal of the Korean housing association
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• v.17 no.5
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• pp.137-146
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• 2006

This study was aimed to analyze the influences of urban expansion by developing a new large scale residential district on changes of whole urban spatial structure. For the analysis, time serial analysis was conducted on the Daejeon Metropolitan City by using the space syntax method. The results of the study are as follows ; First, an expansion of urban area led to lower both of the local and global integration levels, second, the spatial occupation ratio of upper 10% in the whole integration showed that old city center was separated, and moved to the Dunsan District, third, the results also showed that an integration of the old city center region maintained a high level in spite of a movement of city center and its local integration still had highest level so that the old city center will take one of the two city center roles together with Dunsan District.

• Journal of the Korean Geographical Society
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• v.29 no.3
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• pp.360-368
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• 1994

To this day, a number of quantitative analytical methods have been employed in clarifying regional characteristics in the discipline of geography. This paper attempted, as a part of application of those quantitative analyses, to make clear the urban functions and consequently the urban characteristics statistically by adopting newly-introduced CHAID, a sort of discriminant analyis technique. The processing of data was sonducted in two phases. To begin with, the urban functions were classified after designating twenty cities - the population of each city counting 250, 000 or more - as predictor variable, and at the same time four major urban functions like administration, marketing, finance and production as response variable. And then, preeminent functions of individual region were discriminated and concurrently classified by treating the remaining traffic, education, medicare, culture and transportation functions as predictor variable, and the following five regions as response variable: Metropolitan Seoul Area. Pusan region, Taegu region, Kwangju region and Chungcheong region. According to the result of this analysis, marketing and administration are emereed as meaningful functions in Seoul and Taegu respectively. As for the finance function only Pusan and Pucheon can be discriminated. Seoul, Pusan and Seongnam reveal their dominancy in production function. To take a look at the result of the latter analysis, the Metropolitan Seoul area shows, among other functions, strong traffic and finance functions. When it comes fo Pusan region, adminstration, education and finance functions are recorded as a leading ones, and Taegu region is preferable in education, medicare and transportation functions. In case of Kwangju region adminstration, production and education functions are discriminated from any other functions. Chungcheong region shows similar aspect with only traffic function replacing the production function of Kwangju region. Based on aforementioned anlysis, it can be said that the CHAID technique, which is capable of processing large amount of categorical data and, by presenting its outcome in the form of dendrogram, facilitates the interpretation work, is an effective, meaningful means to classify and discriminate certain geographical regions and their characteristics.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.2
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• pp.137-145
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• 1997

To predict the effects of air pollutant in the coastal region, we have developed the air pollutant model, the reaction model and the deposition of NO, $NO_2, and O_3$. And the numerical model of air pollutant concentration employed the nested technique to calculate with the higher resolution for the area. The nested technique used two grid systems, one for the large scale calculating region with the coarse mesh grid (CMG) and the other for the small scale region with the fine grid (FMG). In other to prove the validity of the simulation model the calculations were conducted for the present situation. The results of them reasonably agree with the observed data and proved the validity of the model.

• Journal of the Korean Society for Railway
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• v.7 no.4
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• pp.412-417
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• 2004

In urban rail transit systems, ground faults in the DC traction power supply system are currently detected by the potential relay, 64P. Though it detects the fault it cannot identify the faulted region and therefore the faulted region could not be isolated properly. Therefore it could cause a power loss of the trains running on the healthy regions and the safety of the passengers in the trains could be affected adversely. Two new ground fault protective relay schemes that can identify the faulted region are presented in this paper. A current limiting device, called Device X, is newly introduced in both system, which enables large amount of ground fault current flow upon the positive line to ground fault. One type of the relaying schemes is called directional and differential ground fault protective relay which uses the current differential scheme in detecting the fault and uses the permissive signal from neighboring substation to identify the faulted region correctly. The other is called ground over current protective relay. It is similar to the ordinary over current relay but it measures the ground current at the device X not at the power feeding line, and it compares the current variation value to the ground current in Device X to identify the correct faulted line. Though both type of the relays have pros and cons and can identify the faulted region correctly, the ground over current protective relaying scheme has more advantages than the other.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.4
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• pp.394-407
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• 2016

The spatial air pollution distribution of the Ulsan metropolitan region (UMR) was analyzed using monitoring data and high-resolution numerical simulations. A three-year (2011~2014) analysis for the average concentrations from the 13 air quality monitoring sites in the UMR showed that $SO_2$ and $PM_{10}$ levels in industrial regions were much higher than those in other regions, whereas spatial differences of $NO_2$ and CO concentrations were not significant. In particular, elevated $O_3$ concentrations were clearly found at urban sites near petrochemical complex area. Results from high-resolution simulations by CMAQ model performed for four months of 2012 showed large spatial variations in grid-average pollutant concentrations between industrial areas and other areas in the UMR, which displayed significant changes with wind pattern by season. It was noted that the increases of $SO_2$ and $PM_{10}$ levels were limited in costal industrial areas or over the area nearby the sea in all seasons. Modeled $O_3$ concentrations were quite low in industrial areas and main urban roads with large $NO_x$ emissions. However, the model presented that all pollutant concentrations were significantly increased in the urban residential areas near the industrial complexes in summer season with increase of southerly wind.

• Asian Journal of Atmospheric Environment
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• v.9 no.4
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• pp.259-271
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• 2015

This study conducted analyses on biogenic volatile organic compounds (BVOC) emission sources contributing to urban ozone ($O_3$) concentration in Osaka Prefecture, Japan in summer 2010 by using the Weather Research and Forecasting model (WRF) version 3.5.1 and the Community Multiscale Air Quality model (CMAQ) version 5.0.1. This prefecture is characterized by highly urbanized area with small forest area. The contributions of source regions surrounding Osaka were estimated by comparing the baseline case and zero-out cases for BVOC emissions from each source region. The zero-out emission runs showed that the BVOC emissions substantially contributed to urban $O_3$ concentration in Osaka (10.3 ppb: 15.9% of mean daily maximum 1-h $O_3$ concentration) with day-by-day variations of contributing source regions, which were qualitatively explained by backward trajectory analyses. Although $O_3$ concentrations were especially high on 23 July and 2 August 2010, the contribution of BVOC on 23 July (35.4 ppb: 25.6% of daily maximum $O_3$) was much larger than that on 2 August (20.9 ppb: 14.2% of daily maximum $O_3$). To investigate this difference, additional zero-out cases for anthropogenic VOC (AVOC) emissions from Osaka and for VOC emissions on the target days were performed. On 23 July, the urban $O_3$ concentration in Osaka was dominantly increased by the transport from the northwestern region outside Osaka with large contribution of $O_3$ that was produced through BVOC reactions by the day before and was retained over the nocturnal boundary layer. On 2 August, the concentration was dominantly increased by the local photochemical production inside Osaka under weak wind condition with the particularly large contribution of AVOC emitted from Osaka on the day.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.30-35
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• 2007

Waste policies with waste metering system and recycling in 1995 have contributed to the reduction of solid waste generation. Now rural areas as well as urban areas produce less amount of solid wastes in terms of per capita. However most policies in relation to waste issue have been concentrated in urban areas. Large portion of agricultural waste in rural region are being illegally treated such as open incineration or burned out on the road. In this study, we assessed the atmospheric air quality and health risk by illegal open incineration in rural region. In case of benzene level, worst concentration during illegal open incineration was 0.23 ppm and cancer risk by exposure was estimated to $2.29{\times}10^{-3}$.

• Korean Journal of Rural Living Science
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• v.6 no.2
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• pp.121-136
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• 1995

The purposes of this research are to find out the standards which mothers consider seriously when choosing a day care center and mother's perception for the quality criteria of day care center, and to estimate the differences of these according to region. The sample consisted of 568 mothers with children using day care center located at the city of Taegu and Dalsung Gun. Collected data were analyzed by frequency, Percentage, chi-square, t-test, chronbach's $\alpha$. The results are summerized as follows : 1. In mother's perception for the quality criteria of day care center, the mothers living in the large city perceived more importantly in staff qualifications, administration - evaluation, staff- parent/staff- child interaction, curriculum, staffing, physical environment nutrition, health and safty than mothers in rural community. 2. In the importance classified by domains of the quality criteria of day care center, there were statistically significant differences according to the variable of region in staff qualifications, staff-parent/staff-child interaction, curriculum, staffing, physical environment 3. Given the present situations (income, transportation, location of workplace, etc.), when mothers choose a day care center, generally, staff-parent/staff-child interaction was the most important factor. And according to region, the distance to workplace or home was the most important factor in the case of mothers living in the large city, on the other hand, staff-parent/staff-chad interaction was the most important factor in the case of mothers living in rural community when mothers choose an ideal day care center, generally staff-parent/staff-chad interaction was the most important selection standard, and there were not remarkable differences according to region.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.1
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• pp.93-109
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• 2020

The purpose of this study is to examine the effects of industrialization and urbanization of Gwangyang Bay Region on the change of urban system and spatial structure between triangle-cities located in Gwangyang Bay, Yeosu City, Suncheon City, and Gwangyang City, one of the famous industrial zones in Korea. Large-scale development projects carried out by the central government in the Gwangyang Bay Region such as construction of the Second Oil Refinery in the mid-1960s, completion of the POSCO Gwangyang Steelworks in the mid-1980s, construction of the Gwangyang Port Container Terminal in 1987 and designation of the Gwangyang Bay Area Free Economic Zone in 2003, and EXPO 2012 Yeosu Korea, affected to changes of the urban system and spatial structure between triangle-cities in Gwangyang Bay Region. The above four-development projects transformed the urban and spatial structures between the three cities in the Gwangyang Bay Region from a mononuclear urban system centered on Suncheon to a network city system. Historically, Suncheon has served as an exclusive center in the eastern region of Jeonnam, including the Gwangyang Bay Region. However, the hosting of the 2012 Yeosu Expo Korea is reorganizing the three cities into a network-type spatial structure with the strengthening of connectivity and integration in the region. And this trend is expected to intensify in the future.

• Atmosphere
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• v.29 no.4
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• pp.381-390
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• 2019

This study investigates the impacts of urban land-use fraction and temperature advection on the urban heat island intensity over the Seoul metropolitan area using the UM (Unified Model) with the MORUSES (Met Office Reading Urban Surface Exchange Scheme) during the heat wave over the region from 2 to 8, August 2016. Two simulations are performed with two different land-use type, the urban (urban simulation) and the urban surfaces replaced with grass (rural simulation), in order to calculate the urban heat island intensity defined as the 1.5-m temperature difference between the urban and the rural simulations. The land-use type for the urban simulation is obtained from Korea Ministry of Environment (2007) land-use data after it is converted into the types used in the UM. It is found that the urban heat island intensity over high urban-fraction regions in the metropolitan area is as large as 1℃ in daytime and 3.2℃ in nighttime, i.e., the effects of urban heat island is much larger for night than day. It is also found that the magnitude of urban heat island intensity increases linearly with urban land-use fraction. Spatially, the estimated the urban heat island intensities are systematically larger in the downwind regions of the metropolitan area than in the upwind area due to the effects of temperature advection. Results of this study indicate that urban surface fraction in the city area and temperature advection play a key role in determining the spatial distribution and magnitude of urban heat island intensity.