• Journal of the Economic Geographical Society of Korea
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• v.16 no.3
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• pp.445-457
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• 2013

This paper aims to investigate changes in the characteristics of urban spatial structure in Korea by regional groups and city size between 2000 and 2010. The characteristics of urban spatial structure is analyzed by Clark's population gradient curve in this paper. Therefore key parameters in population gradient function, such as population density gradients and population density in CBD represent the characteristics of urban spatial structure. The result shows that most of cities in Korea have experienced suburbanization rather than concentration, but small-size cities have experienced concentration during the period.

• Journal of the Korean Geographical Society
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• v.38 no.6
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• pp.863-886
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• 2003

Internet is the most important element in the emergence of the Internet economy, which derives the creation of new firms and employment, and brings about the new ways of marketing and business. The emergence of the Internet economy and the rapid growth of the Internet industry have a great deal to changes in the spatial economy. Korea has experienced a rapid growth of the Internet industries, but few geographical studies have been done to explain the impact of the development of the Internet industries on the spatial economy. This research explored how Korea has developed as a nation of the strong Internet economy in terms of driving forces by demand and supply side. This research tried to build a data set for the Internet industries with the introduction of a new classification scheme and a measurement. The most important finding from this research was the spatial concentration of the Internet industries toward Seoul at the national level and toward the Gangnam area within Seoul. The rise of Internet industries has added attractiveness to Seoul which enjoys a kind of cumulative and circular advantages.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.124-132
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• 2022

This study was aimed to visualize the spatial distribution of PM₁₀ data measured at non-uniformly distributed observation sites in South Korea. Different spatial interpolation methods were applied to irregularly distributed PM₁₀ observation data from January, 2019, when the concentration was the highest and in July, 2019, when the concentration was the lowest. Four interpolation methods with different parameters were used: Inverse Distance Weighted (IDW), Ordinary Kriging (OK), radial base function, and scattered interpolation. Six cases were cross-validated and the normalized root-mean-square error for each case was compared. The results showed that IDW using smoothing-related factors was the most appropriate method, while the OK method was least appropriate. Our results are expected to help users select the proper spatial interpolation method for PM₁₀ data analysis with comparative reliability and effectiveness.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.5
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• pp.583-591
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• 2004

In this study, methodologies for the rational organization of air pollution monitoring network were examined by understanding the characteristics of temporal and spatial distribution of secondary air pollution, whose significance would increase hereafter. The data on $O_3$ and $NO_2$ concentrations during high ozone period in 1998~1999 recorded at the nine air pollution monitoring station in Busan were analysed using principal component analysis (PCA) and cumulative semivariogram. It was found that the ozone concentration was deeply associated with the daily emission characteristics or the $O_3$ precusors, and nitrogen dioxide concentration largely depends on the emission strength of regional sources. According to the spatial distribution analysis of ozone and nitrogen dioxide in Busan using cumulative semivariograms, the number of monitoring stations for the secondary air pollution can be reduced in east-west direction, but reinforced in north-south direction to explain the spacial variability. More scientific and rational relocation of air pollution monitoring network in Busan would be needed to investigate pollution status accurately and to plan and implement the pollution reduction policies effectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.3
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• pp.78-84
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• 2015

The aim of this study was to evaluate methane emission flux based on spatial methane concentration using laser methane detector, and geospatial methodology (Inverse distance weighting) at a landfill. The obtained results showed that the spatial methane concentrations were in good agreement with the methane emission fluxes. Thus, it was concluded that the methane emission flux could be derived from spatial methane concentrations. In addition, the results of the geospatial calculations showed that 12.85% of the total area contributed more than 42.21% of total flux. This suggested that the geospatial methodology might be essential in chamber method to determine accurate methane emission fluxes from landfills.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.6
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• pp.607-616
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• 2012

The need for management of tunnel air quality is imminent considering the rapid increase of number and span of tunnels in Korea. To investigate spatial distribution of $CO_2$ within tunnels, $CO_2$ were measured and model simulations were performed in Namsan 1 tunnel. Results show that $CO_2$ concentrations were 250 ppm to 400 ppm higher in the exit than tunnel entrance. Also, $CO_2$ concentrations were 200 ppm to 300 ppm lower inside no ventilating vehicle than in the tunnel. Both experimental and model simulation results show that spatial distribution and concentration gradient of air pollutant inside tunnel are highly dependent on traffic density.

• Spatial Information Research
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• v.22 no.4
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• pp.49-58
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• 2014

Natural disasters of large scale such as typhoon, heat waves and snow storm have recently been increased because of climate change according to global warming which is most likely caused by greenhouse gas in the atmosphere. Increase of greenhouse gases concentration has caused the augmentation of earth's surface temperature, which raised the frequency of incidences of extreme weather in northern hemisphere. In this paper, we present spatial analysis of future typhoon genesis based on IPCC AR5 RCP 8.5 scenario, which applied latest carbon dioxide concentration trend. For this analysis, we firstly calculated GPI using RCP 8.5 monthly data during 1982~2100. By spatially comparing the monthly averaged GPIs and typhoon genesis locations of 1982~2010, a probability density distribution(PDF) of the typhoon genesis was estimated. Then, we defined 0.05GPI, 0.1GPI and 0.15GPI based on the GPI ranges which are corresponding to probability densities of 0.05, 0.1 and 0.15, respectively. Based on the PDF-related GPIs, spatial distributions of probability on the typhoon genesis were estimated for the periods of 1982~2010, 2011~2040, 2041~2070 and 2071~2100. Also, we analyzed area density using historical genesis points and spatial distributions. As the results, Philippines' east area corresponding to region of latitude $10^{\circ}{\sim}20^{\circ}$ shows high typhoon genesis probability in future. Using this result, we expect to estimate the potential region of typhoon genesis in the future and to develop the genesis model.

• Journal of Families and Better Life
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• v.26 no.5
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• pp.195-209
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• 2008

The purpose of this study was to provide basic information about design guidelines of activity areas in elderly nursing facilities. For the study, the activity areas of 44 facilities in Korea were investigated to categorize their spatial compositions and forms, and then a case study about 19 facilities was conducted to analyse their hierarchical characteristics. The results of the study were as follows: First, the major type of spatial composition among 44 research facilities was concentration, but compartment type was the main among unit-care facilities. By the year, all the types of spatial composition were evenly distributed during recent five years, while concentration type was about 40% before 2003. Second, the major form of activity areas was hall or corridor extension for large group. But there was more alcove or separation form among small group spaces. Third, in the case analysis about hierarchical characteristics, hall and corridor extension form met the requirements of accessibility and openness of public and semi-public areas. On the other hand, separation form had a problem in satisfying both requirements. The semi-private areas, which were around the elderly bedrooms and the elderly were able to watch activities in, were not sufficient in many facilities. Fourth, the division of public and semi-public area was mainly by furniture, and the individuality of semi-private area was defined by dead-end place and corner seats of the window or the corridor. The diversity of semi-private area was likely to be appeared in connection or distribution type. On the basis of the results, the basic design guidelines for activity areas in elderly nursing facilities could be suggested as follows: On the whole, connection or distribution type in spatial composition is more efficient for hierarchical flow than concentration or compartment type is, especially in Korean facilities having many elderly residents per floor. In detail, the design of public and semi-public area should be focused on their openness and accessibility. The recommended forms of activity areas were hall or corridor extension in public area, and living room, corridor extension, or large corridor in semi-public area to effectively function as large or small group spaces. In semi-private areas, the spatial diversity and individuality should be considered.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1972-1979
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• 2003

Transport of a scalar quantity, such as chemical concentration or temperature, is important in many engineering applications and environmental flows. Here we report on results obtained from the large eddy simulations of flow and concentration fields inside the tank performed using a spectral multi-domain technique. The computations were driven by specifying the impeller-induced flow at the blade tip radius (Yoon et al. $^{(1)}$). This study focused on the concentration development at different molecular diffusivities in a stirred tank operated under turbulent conditions. The main objective of the work presented here is to study the large-scale mixing structure at different molecular diffusivities in a stirred tank by using the large eddy simulation. The time sequence of concentration and flow fields shows the flow dependency of the concentration development. The presence of spatial inhomogenieties is detailed by observing the time variation of local concentration at different positions.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.221-229
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• 2022

This study was aimed to investigate spatial and vertical characteristics of greenhouse environments according to the location of the environmental sensors, and to investigate the correlations between temperature, light intensity, and carbon dioxide (CO₂) concentration according to the type of greenhouse. Temperature, relative humidity (RH), CO₂, and light sensors were installed in the four-different vertical positions of the whole canopy as well as ground and roof space at the five spatial locations of the Venlo greenhouse. Also, correlations between temperature, light intensity, and CO₂ concentration in Venlo and semi-closed greenhouses were analyzed using the Curve Expert Professional program. The deviations among the spatial locations were larger in the CO₂ concentration than other environmental factors in the Venlo greenhouse. The average CO₂ concentration ranged from 465 to 761 µmol·mol^-1 with the highest value (646 µmol·mol^-1) at the Middle End (4ME) close to the main pipe (50Ø) of the liquefied CO₂ gas supply and lowest (436 µmol·mol^-1) at the Left Middle (5LM). The deviation among the vertical positions was greater in temperature and relative humidity than other environments. The time zone with the largest deviation in average temperature was 2 p.m. with the highest temperature (26.51℃) at the Upper Air (UA) and the lowest temperature (25.62℃) at the Lower Canopy (LC). The time zone with the largest deviation in average RH was 1 p.m. with the highest RH (76.90%) at the LC and the lowest RH (71.74%) at the UA. The highest average CO₂ concentration at each hour was Roof Air (RF) and Ground (GD). The coefficient of correlations between temperature, light intensity, and CO₂ concentration were 0.07 for semi-closed greenhouse and 0.66 for Venlo greenhouse. All the results indicate that while the CO₂ concentration in the greenhouse needs to be analyzed in the spatial locations, temperature and humidity needs to be analyzed in the vertical positions of canopy. The target CO₂ fertilization concentration for the semi-closed greenhouse with low ventilation rate should be different from that of general greenhouses.