• Journal of Korean Society of Forest Science
• /
• v.95 no.3
• /
• pp.240-249
• /
• 2006

Recently, dispersion of damaged forest by pine wilt disease has been regarded as a serious social issue. Damages by pine wilt disease have been spreaded by natural area expansion of the vectors in the damaged area, while the national wide damage spread has induced by human-involved carrying infected trees out of damaged area. In this study, damaged trees were detected and located on the digital map by aerial photograph and terrestrial surveys. The spatial distribution pattern of damaged trees, and the relationship of spatial distribution of damaged trees and some geomorphological factors were geostatistically analysed. Finally, we maked natural spread pattern map of pine wilt disease using geostatistical CART(Classification and Regression Trees) model. This study verified that geostatistical analysis and CART model are useful tools for understanding spatial distribution and natural spread pattern of pine wilt diseases.

• Journal of Korean Society for Atmospheric Environment
• /
• v.17 no.1
• /
• pp.1-17
• /
• 2001

The high-ozone episode in the Greater Seoul Area for the period of July 27 to August 1 1997 was modeled by the CIT(California Institute of Technology) three-dimensional photochemical model. Emission data were prepared by scaling the NIER(1994) data through and optimization method using VOC measurements in August 1997 and EKMA(Empirical Kinetic Modeling Approach). Two sets of meteorological data were prepared by the diagnostic routine. a part of the CIT model : one only utilized observations from the surface weather stations and the other also utilized observations from the automatic weather stations that were more densely distributed than those from the surface weather stations. The results showed that utilizing observations from the automatic weather stations could represent fine variations in the sind field such as those caused by topography. A better wind field gave better peak ozones and a more reasonable spatial distribution of ozone concentrations. Nevertheless, there were still many differences between predictions and observations particularly for primary pollutant such as NOx and CO. This was probably due to the inaccuracy of emission data that could not resolve both temporal and spatial variations.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.11 no.4
• /
• pp.64-75
• /
• 2008

Since the current database systems for managing geotechnical investigation results were limited by being described boring test result in point feature, it has been trouble for using other GIS data. Although there are some studies for spatial characteristics of subsurface modeling, it is rather lack of being interoperable with GIS, considering geotechnical engineering facts. This is reason for difficulty of practical uses. In this study, we has developed subsurface spatial information model through extracting needed geotechnical engineering data from geotechnical information DB. The developed geotechnical information clustering program(GEOCL) has made a cluster of boring formation(and formation ratio), classification of layer, and strength characteristics of subsurface. The interpolation of boring data has been achieved through zonal kriging method in the consideration of spatial distribution of created cluster. Finally, we make a subsurface spatial information model to integrate with digital elevation model, and visualize 3-dimensional model by subsurface spatial information viewing program(SSIVIEW). We expect to strengthen application capacity of developed model in subsurface interpretation and foundation design of construction works.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.25 no.3
• /
• pp.74-99
• /
• 2022

Surface ozone is produced by photochemical reactions of nitrogen oxides(NOx) and volatile organic compounds(VOCs) emitted from vehicles and industrial sites, adversely affecting vegetation and the human body. In South Korea, ozone is monitored in real-time at stations(i.e., point measurements), but it is difficult to monitor and analyze its continuous spatial distribution. In this study, surface ozone concentrations were interpolated to have a spatial resolution of 1.5km every hour using the stacking ensemble technique, followed by a 5-fold cross-validation. Base models for the stacking ensemble were cokriging, multi-linear regression(MLR), random forest(RF), and support vector regression(SVR), while MLR was used as the meta model, having all base model results as additional input variables. The results showed that the stacking ensemble model yielded the better performance than the individual base models, resulting in an averaged R of 0.76 and RMSE of 0.0065ppm during the study period of 2020. The surface ozone concentration distribution generated by the stacking ensemble model had a wider range with a spatial pattern similar with terrain and urbanization variables, compared to those by the base models. Not only should the proposed model be capable of producing the hourly spatial distribution of ozone, but it should also be highly applicable for calculating the daily maximum 8-hour ozone concentrations.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.47 no.5
• /
• pp.3-13
• /
• 2005

The present study examined the 3 dimensional space distribution characteristics of sea water intrusion using data available from previous observations. For this study, we used 3D FEMWATER, which is a 3 dimensional finite element model. The target area was around Daechang-ri, Gimje-si, Jeollabuk-do. The area is relatively easy to formulate a conceptual model and has observation wells in operation for surveying sea water intrusion. Considering the uncertainty of numerical simulation, we analyzed sensitivity to hydraulic conductivity, which has a relatively higher effect. According to the result of the analysis, the variation of TDS concentration had an error range of $-1,336{\~}+107 mg/{\iota}$. Taking note that the survey data from observation wells were collected when the boundary between fresh water and sea water in the aquifer was in equilibrium, we set the range of time for numerical simulation and estimated the spatial distribution of TDS concentration as the range of sea water intrusion. According to the result of estimation, the spatial distribution of TDS concentration calculated when 1,440 days were simulated was taken as the range of sea water intrusion. Using the result of calculation, we can draw not only vertical views for a certain section but also horizontal views of different depth. These views will be greatly helpful in understanding the spatial distribution of the range of sea water intrusion. In addition, the result of this study can be used rationally in proposing an optimal quantity of water pumping through investigating the moving route of sea water intrusion over time in order to prevent excessive water pumping and to maintain an optimal number of water pumping wells per interval.

• Journal of the Korean Society for Library and Information Science
• /
• v.56 no.4
• /
• pp.377-397
• /
• 2022

The number of public libraries in Korea has been increasing. However, the focus was on quantitative growth, while it did not have much interests in whether its growth trend are have deviations by region, and if that is a fact, what factors caused such a disparity. For this reason, this study analyzes spatial distribution of public libraries in Korea and its affecting factors of regional gap. As a result, public libraries are constantly distributing in the metropolitan area and the distribution of public libraries showed deviations by region. The results of analysis regarding the determinants of public libraries distribution, rate of population growth, the number of businesses and financial independence rate are found to have a positive effect but local taxes per capita are not. Especially economic power of region and financial ability of a local government are key factors of regional disparity. It shows empirically that the supply of public libraries has been determined by the convenience of suppliers.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.25 no.3
• /
• pp.29-45
• /
• 2022

For biodiversity conservation, the importance of beta-diversity which is changes in the composition of species according to environmental changes has become emphasized. However, given the systematic investigation of species distribution and the accumulation of large amounts of data in the Republic of Korea(ROK), research on the spatialization of beta-diversity using them is insufficient. Accordingly, this research investigated the applicability of the Generalized Dissimilarity Modeling(GDM) to ROK, which can predict and map the similarity of compositional turnover (beta-diversity) based on environmental variables. A brief overview of the statistical description on using GDM was presented, and a model was fitted using the flora distribution data(410,621points) from the National Ecosystem Survey and various environmental spatial data including climate, soil, topography, and land cover. Procedures and appropriated spatial units required to improve the explanatory power of the model were presented. As a result, it was found that geographical distance, temperature annual range, summer temperature, winter precipitation, and soil factors affect the dissimilarity of the vegetation community composition. In addition, as a result of predicting the similarity of vegetation composition across the nation, and classifying them into 20 and 100 zones, the similarity was high mainly in the central inland area, and tends to decrease toward the mountainous areas, southern coastal regions, and island including Jeju island, which means the composition of the vegetation community is unique and beta diversity is high. In addition, it was identified that the number of common species between zones decreased as the geographic distance between zones increased. It classified the spatial distribution of plant community composition in a quantitative and objective way, but additional research and verification are needed for practical application. It is expected that research on community-level biodiversity modeling in the ROK will be conducted more actively based on this study.

• Journal of Korea Water Resources Association
• /
• v.40 no.12
• /
• pp.943-956
• /
• 2007

Among various statistics, the spatial correlation function, that is "correlogram", is frequently used to evaluate or design the rain gauge network and to model the rainfall field. The spatial correlation structure of rainfall has the significant variation due to many factors. Thus, the variation of spatial correlation structure of rainfall causes serious problems when deciding the spatial correlation function of rainfall within the basin. In this study, the spatial rainfall structure was modeled using bivariate mixed distributions to derive monthly spatial correlograms, based on Gaussian and lognormal distributions. This study derived the correlograms using hourly data of 28 rain gauge stations in the Keum river basin. From the results, we concluded as following; (1) Among three cases (Case A, Case B, Case C) considered, the Case A(+,+) seems to be the most relevant as it is not distorted much by zero measurements. (2) The spatial correlograms based on the lognormal distribution, which is theoretically as well as practically adequate, is better than that based on the Gaussian distribution. (3) The spatial correlation in July exponentially decrease more obviously than those in other months. (4) The spatial correlograms should be derived considering the temporal resolution(hourly, daily, etc) of interest.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.15 no.4
• /
• pp.162-174
• /
• 2012

To visualize the characteristics of vertical seawater temperature data, in the ocean having 3D spatial characteristics, 2D thematic maps like horizontal seawater temperature distribution map at each depth layer and 3D volume model using 3D spatial interpolation are used. Although these methods are useful to understand oceanographic phenomena visually, there is a limit to analyze the spatial pattern of vertical temperature distribution or the relationship between vertical temperature characteristics and other oceanic factors (seawater chemistry, marine organism, climate change, etc). Therefore, this study aims to determine the spatial distribution characteristics of vertical temperature profiles in the South Sea of Jeju by quantifying the characteristics of vertical temperature profiles by using an algorithm that can extract the thermocline parameters, such as mixed layer depth, maximum temperature gradient and thermocline thickness. For this purpose spatial autocorrelation index (Moran's I) was calculated including mapping of spatial distribution for three parameters representing the vertical temperature profiles. Also, after grouping study area as four regions by using cluster analysis with three parameters, the characteristics of vertical temperature profiles were defined for each region.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.8
• /
• pp.27-34
• /
• 2018

Purpose - This paper discussed and illustrated the most efficient method to calculate the distribution centers for a national project in China. Through demonstration of implementing the GIS, spatial analysis, and location calculation model, this paper mainly dealt with the construction distribution problem and inconvenient supply of materials problems. Research design, data, and methodology - In this paper, the research design structure based on three steps: implementing the Geographic Information System to locate the points coordination data, calculating the distribution centers of the project, and optimizing the most efficient and effective coordination. The data of the calculation is from an actual project. The methodology of this paper is summarizing the spatial analysis capabilities and digital graphic data calculation to locate logistics distribution centers, and since the illustration of the calculation is useful for locating the coordination, the result of this paper has certain reference values for the project construction. Results - This paper illustrates the steel and cement resource of every distribution point to confirm the most efficient distribution center location coordination. Conclusions - The integrated logistical management models are used to ensure the results for the purposes of our calculation. The result of the calculation is also a useful example for future Chinese national projects.