• Journal of the Korean Regional Science Association
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• v.40 no.1
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• pp.89-110
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• 2024

REITs are very closely related to real estate management, but there have been no prior studies analyzing the location of REITs assets. Therefore, this study analyzed the location characteristics of REITs assets in two aspects to clarify the location characteristics by using spatial information of REITs assets. First, the characteristics of the type of city where REITs assets are distributed were analyzed, and second, the characteristics of the zoning where REITs assets are distributed were analyzed. As a result of analyzing the characteristics of the city where REITs assets are distributed by type, it was analyzed that in the case of the capital area, both the ratio of cities with REITs assets location and the intensity of REITs assets location (number of REITs assets per city) have location characteristics by city hierarchy in the order of metropolitan city > big city > small and medium-sized city. In the case of non-capital area's metropolitan and large cities, the ratio of REITs assets location cities is similar to that of the capital area, but the location intensity of REITs assets was analyzed to be significantly lower than that of the capital area. As a result of the analysis of REITs assets by type, housing REITs assets tend to be located in the old downtown commercial zoning and the new downtown residential zoning, office REITs assets are characterized by concentration of location in specific commercial zoning of Seoul, and retail REITs assets are located mainly in the old downtown station area. In addition, it was found that logistics REITs assets tend to be located in management zoning, centering on key logistics hub cities in the region.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.19-31
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• 2023

According to the climate change scenarios, the intensity of typhoons, a major factor in Korea's natural disaster, is expected to increase. The increase in typhoon intensity leads to a rise in wave heights, which is likely to cause large-scale disasters in coastal regions with high populations and building density for dwelling, industry, and tourism. This study, therefore, analyzed observation data of the Donghae ocean data buoy and conducted a numerical model simulation for wave estimations for the typhoon MAYSAK (202009) period, which showed the maximum significant wave height. The boundary conditions for wave simulations were a JMA-MSM wind field and a wind field applying the typhoon central pressure reduction rate in the SSP5-8.5 climate change scenario. As a result of the wave simulations, the wave height in front of the breakwater at Sokcho port was increased by 15.27% from 4.06 m to 4.68 m in the SSP5-8.5 scenario. Furthermore, the return period at the location of 147-2 grid point of deep-sea design wave was calculated to increase at least twice, it is necessary to improve the deep-sea design wave of return period of 50-year, which is prescriptively applied when designing coastal structures.

• Journal of the Korean Regional Science Association
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• v.40 no.2
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• pp.107-130
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• 2024

Urban land surface temperature (LST) change is a major environmental factor that affects the thermal comfort, energy consumption, and health of urban residents. Most studies that explored the relationship between LST and urban built-environment form analyzed only midday LST. This study explores the diurnal variation of summertime LST in Seoul using ECOSTRESS data, which observes LST at various times of the day and analyzes whether the LST variation differs by built environment type. Launched in 2018, ECOSTRESS operates in a non-sun-synchronous orbit, observing LST with a high resolution of 70 meters. This study collected data from early morning (6:25) to evening (17:26) from 2019 to 2022 to build time-series LST. Based on greenery, water bodies, and building form data, eight types of Seoul's built environment were derived by hierarchical clustering, and the LST fluctuation characteristics of each cluster were compared. The results showed that the spatial disparity in LST increased after dawn, peaked at noon, and decreased again, highlighting areas with rapid versus stable LST changes. Low-rise and high-rise compact districts experienced fast, high temperature increases and high variability, while low-density apartments experienced moderate LST increases and low variability. These results suggest urban forms that can mitigate rapid daytime heating.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.52-66
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• 2024

The purpose of this study is to identify the spatial system and characteristics of the urban center by deriving the boundaries of the urban center set in the urban basic plan for Busan Metropolitan City and diagnosing the role and status of the center. To this end, four indicators representing the characteristics of the center were selected through a review of previous studies, and the boundaries of the center were derived using spatial statistical techniques with strengths in geographical boundary analysis. Then, using the indicators of center characteristics and population potential functions, we diagnosed the influence and potential of each center in the spatial structure of Busan Metropolitan City. The analysis showed that the scale of the centers varies greatly, and the unutilized areas where commercial areas are not activated and the expansion areas that spread beyond commercial areas to residential and industrial areas are different for each urban center. The results of the potential measurement, which indicates the attractiveness of the center, also showed areas with strong and weak population potential. Therefore, systematic management and strategies based on the hierarchical characteristics and influence measurement results are needed to strengthen the function of urban centers. The results analyzed in this study can be used as a resource for responding to various urban planning needs and policy changes in the future, along with station area development plans and spatial innovation zones for building a sustainable urban growth system, balanced development, and strengthening the function of centers.

• Journal of the Economic Geographical Society of Korea
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• v.21 no.1
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• pp.20-33
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• 2018

Population distribution in urban space varies with transportation flow changing along time of day. Transportation flow is directly affected by the activities of urbanites and the distribution of related facilities, since the flow is the result of moving to the point where the facilities associated with their activities are located. It is thus necessary to analyze the spatio-temporal characteristics of the urban population distribution by integrating the distribution of activity spaces related to the daily life of urbanites and the flow of transportation. The purpose of this study is to analyze the population distribution in urban space with daily and weekly time bases using the building database and T-card database in the city of Seoul, which is rich in information on land use and transportation flow. For a time-based analysis that is difficult to grasp by general statistical techniques, a four-dimensional visualization method combining time and space using a Java program is devised. Dynamic visualization in the four-dimensional space and time allows intuitive analysis and makes it possible to understand more effectively the spatio-temporal characteristics of population distribution. For this purpose, buildings are classified into three activity groups: residential, working, and commercial according to their purpose, and the number of passengers traveling to and from each stop site of bus and subway networks in the T-card database for one week is calculated in one-minute increments, Visualizing these and integrating transportation and land use, we analyze spatio-temporal characteristics of the population distribution in Seoul. As a result, it is found that the population distribution of Seoul displays distinct spatio-temporal characteristics according to land use. In particular, there is a clear difference in the population distribution pattern along the time axis according to the mixed aspects of working, commercial, and residential activities. The results of this study can be very useful for transportation and location planning of city facilities.

• Journal of the Korean association of regional geographers
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• v.7 no.1
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• pp.83-95
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• 2001

The purpose of this study is to examine that we can estimate land use by land values in 5 great cities. For this purpose, I calculated the percentage that each lot value makes up of the highest land values in the city as a indicator. I think this rate is very useful in the comparative study about many cities. At first, I set up four hypotheses based on my preceding studies. Hypothesis 1, the range of CBD can be estimated as having about 10% of the peak land values. Hypothesis 2, when the peak rate of concentric circle of land values seperated from CBD circle is about 30% of the peak land values, that is sub-CBD. Hypothesis 3, generally, a lot of having about 5% of the peak land values represents residential land commercial land use. Hypothesis 4, a lot of having about 3% of the peak land values represents only residential land use. The data on land values in five great cities were got from public notification on land values(1999) of the Ministry of Construction & Transportation. I selected highest lot values from many standard lot value in each Tong(the minimum administrative unit) in each cities. And I drew land values isopleth. Through that isopleth, I identified CBD cmd sub-CBD. Through the book of public notification on land values, I identified what land use are lots of having over 10%, about 5%, below 3% of the peak land values. As a result, we identified land use can be estimated by the percentage that each lot value makes up of the highest land values in the city. The bigger urban size becomes and the more stable land use becomes, the higher fitness of hypotheses becomes. The lowest degree of fitness about 4 hypotheses among 5 great cities showed in Inchon. Because Inchon lies adjacent to the greatest Seoul. The percentage that showed the lowest degree of fitness is 5% of the highest land values. The land use on lots of having about 5% of the peak land values is different from each other according to regional character in city.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.496-503
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• 2009

Reclamation area is characterized by high soil salinity and high ground water table that are not favorable environment for tree growth. However, the increasing demand to convert the reclamation area from rice cultivation fields to industrial or residential complex, or parks accompanies the idea of introduction of trees in the area. This study aimed to suggest better performed tree species for the tree planting in the Seosan reclamation area, Chungchungnam-do. Seedlings of 8 tree species (Pinus densiflora, Pinus thunbergii, Metasequoia glyptostroboides, Chionanthus retusus, Cornus kousa, Prunus sargentii, Quercus acutissima, and Zelkova serrata) were planted in 4 types of 10 m ${\times}$ 10 m experimental plots. The survival rate and the height growth of seedlings were measured from April 2006 to November 2008 on an annual basis. The experimental plots were constructed using 2 different soil material (dredged sand and dredged sand + forest soil), and 2 soil covering depth (1.5 m and 2.0 m). The tree species showed different survival rates for 3 years since planting (F = 9.632, P < 0.001). C. kousa, Q. acutissima, and P. sargentii showed high mortality rate while P. thunbergii, M. glyptostroboides and Z. serrata showed lower mortality rates. The seedling height growth for 3 years was also significantly different among species (F=4.749, P=0.002). Most of seedlings showed lower height growth in the second year, and the growth began to recover in the third year after transplanting. The survival rate and the growth of the seedlings were better in higher soil covering depth and forest soil material plots regardless of species. The combination of rank orders in survival rate and relative height growth indicates that P. thunbergii, M. glyptostroboides and Z. serrata would perform better than other species used in the experiment, while C. retusus, C. kousa and P. sargenti may not adapt well to this area.

• Journal of Korea Water Resources Association
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• v.39 no.5 s.166
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• pp.453-466
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• 2006

The objective of this study was to analyze the changes in the hydrological environment in Soyanggang-dam watershed due to climate change results (in yews 2050 and 2100) which were simulated using CCCma CGCM2 based on SRES A2 and B2. The SRES A2 and B2 were used to estimate NDVI values for selected land use using the relation of NDVI-Temperature using linear regression of observed data (in years 1998$\sim$2002). Land use change based on SRES A2 and B2 was estimated every 5- and 10-year period using the CA-Markov technique based on the 1985, 1990, 1995 and 2000 land cover map classified by Landsat TM satellite images. As a result, the trend in land use change in each land class was reflected. When land use changes in years 2050 and 2100 were simulated using the CA-Markov method, the forest class area declined while the urban, bareground and grassland classes increased. When simulation was done further for future scenarios, the transition change converged and no increasing trend was reflected. The impact assessment of evapotranspiration was conducted by comparing the observed data with the computed results based on three cases supposition scenarios of meteorological data (temperature, global radiation and wind speed) using the FAO Penman-Monteith method. The results showed that the runoff was reduced by about 50% compared with the present hydrologic condition when each SRES and periods were compared. If there was no land use change, the runoff would decline further to about 3$\sim$5%.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.64-80
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• 2018

In Korea, citizens can only know general information about crime. Thus it is difficult to know how much they are exposed to crime. If the police can predict the crime risky area, it will be possible to cope with the crime efficiently even though insufficient police and enforcement resources. However, there is no prediction system in Korea and the related researches are very much poor. From these backgrounds, the final goal of this study is to develop an automated crime prediction system. However, for the first step, we build a big data set which consists of local real crime information and urban physical or non-physical data. Then, we developed a crime prediction model through machine learning method. Finally, we assumed several possible scenarios and calculated the probability of crime and visualized the results in a map so as to increase the people's understanding. Among the factors affecting the crime occurrence revealed in previous and case studies, data was processed in the form of a big data for machine learning: real crime information, weather information (temperature, rainfall, wind speed, humidity, sunshine, insolation, snowfall, cloud cover) and local information (average building coverage, average floor area ratio, average building height, number of buildings, average appraised land value, average area of residential building, average number of ground floor). Among the supervised machine learning algorithms, the decision tree model, the random forest model, and the SVM model, which are known to be powerful and accurate in various fields were utilized to construct crime prevention model. As a result, decision tree model with the lowest RMSE was selected as an optimal prediction model. Based on this model, several scenarios were set for theft and violence cases which are the most frequent in the case city J, and the probability of crime was estimated by $250{\times}250m$ grid. As a result, we could find that the high crime risky area is occurring in three patterns in case city J. The probability of crime was divided into three classes and visualized in map by $250{\times}250m$ grid. Finally, we could develop a crime prediction model using machine learning algorithm and visualized the crime risky areas in a map which can recalculate the model and visualize the result simultaneously as time and urban conditions change.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.630-646
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• 2020

In rural areas, nitrate-nitrogen (NO3-N) pollution caused by agricultural activities is a major obstacle to the use of shallow groundwater as domestic water or drinking water. In this study, the water quality characteristics of shallow groundwater in Hyogyo-ri agricultural area of Yesan-gun, Chungcheongnam-do province was studied in connection with land use and chemical composition of soil layer. The average NO3-N concentration in groundwater exceeds the domestic and agricultural standard water qualities of Korea and is caused by anthropogenic sources such as fertilizer, livestock wastewater, and domestic sewage. The groundwater type mainly belongs to Ca(Na)-Cl type, unlike Ca-HCO3 type, a general type of shallow groundwater. The average NO3-N concentration (7.7 mg L-1) in groundwater in rice paddy/other (upstream, ranch, and residential) area is lower than the average concentration (22.8 mg L-1) in farm field area, due to a lower permeability in paddy area than that in farm field area. According to the trend analysis by the Mann-Kendall and Sen tests, the NO3-N concentration in the shallow groundwater shows a very weak decreasing trend with ~0.011 mg L-1yr-1 with indicating almost equilibrium state. Meanwhile, SO42- and HCO3- concentrations display annual decreasing trend by 15.48 and 13.15%, respectively. At a zone of 0 to 5 m below the surface, the average hydraulic conductivity is 1.86×10-5 cm s-1, with a greater value (1.03×10-4cm s-1) in sand layer and a smaller value (2.50×10-8 cm s-1) in silt layer.