• Economic and Environmental Geology
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• v.37 no.4
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• pp.425-436
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• 2004

The purpose of this study is to analyze the spatial relationship between the landslides occurred by typhoon, Rusa in 2002 and geospatial dataset. Landslide locations were detected using satellite image and field survey. Topogra-phy, soil, forest, geology and land use data sets were constructed as a spatial database in GIS. From the database, slope, aspect, curvature, water system, type of topography, texture, material, drainage, effective thickness of soil, type, age, diameter, density of wood, lithology, lineament of geology, land use and lineament were used as the land-slide occurrence factors. Using a frequence ratio model, the spatial relationships between the landslides and the factors were extracted. The spatial relationships is helpful to explain the characteristics of the landslide, and to make landslide susceptibility map.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.3
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• pp.49-56
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• 2010

The Genetic Algorithm is one of the population surface modelling tool in the field of urban and environmental research based on the gridded population data. Taking the East-Hwasung area as the case, this study first builds a gridded population data based on the GIS databases as well as municipal population survey data. The study then constructs the attribute values of the explanatory variables by way of GIS tools. The regression model constructed with the same variables is also run as a comparative purpose at the same time. It is shown that the GenAlg output predicted as much consistent and meaningful coefficient estimates for the explanatory variables as the regression model, indicating that it is a very useful interdisciplinary research tool to find optimal solutions in urban problems.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.121-128
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• 2016

Many studies are focused on image data and classifier for comparison or improvement of classification accuracy. Therefore studies are needed aspect of the training samples on supervised classification which depend on reference data or skill of analyst. This study tries to assess usability of field spectra as training samples on supervised classification. Classification accuracies of hyperspectral and multispectral images were assessed using training samples from image itself and field spectra, respectively. The results shown about 90% accuracy with training sample collected from image. Using field spectra as training sample, accuracy was decreased 10%p for hyperspectral image, and 20%p for multispectral image. Especially, some classes shown very low accuracies due to similar spectral characteristics on multispectral image. Therefore, field spectra might be used as training samples on classification of hyperspectral image, although it has limitation for multispectral image.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.1 s.6
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• pp.31-41
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• 1996

The analysis of environmental change followed by cultural development is useful for determining development plan hereafter. This study aimed for quantitative analysis about urban sprawl within 10 years, from 1984 to 1994, at Kwangju city, and to extract characteristics of change. For this purpose, we performed land cover classifications using Landsat TM data. And to evaluate influence of urbanization, we carried out surface temperature analysis using TM band 6 data. From the change analysis in land cover, it wa found that expansion of urban areas amounted to 3% and get accomplished by exploitation of farm land area, and that a rice paddy fields were changed to vinyl house areas considerably. In the regional aspect, development was concentrated on Kwangsan-ku which had been incorperated into Kwangju city in 1988. The results from temperature analysis showed that there was close correlation between surface temperature and land cover types, and that urbanization would influnce temperature to rise $0.3^{\circ}C$ in summer. As a results, we can prove that satellite data is very effective for environmental change analysis.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.23-29
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• 2012

Existing pedestrian and evacuation models generally seek to find locally optimal solutions for the shortest or the least time paths to exits from individual locations considering pedestrian's characteristics (eg. speed, direction, sex, age, weight and size). These models are not designed to produce globally optimal solutions that reduce the total evacuation time of the entire pedestrians in a building when all of them evacuate at the same time. In this study, we suggest a globally optimal model for indoor pedestrian evacuation to minimize the total evacuation time of occupants in a building considering different distributions of them. We used the genetic algorithm, one of meta-heuristic techniques because minimizing the total evacuation time can not be easily solved by polynomial expressions. We found near-optimal evacuation path and time by expressing varying pedestrians distributions using chromosomes and repeatedly filtering solutions. In order to express and experiment our suggested algorithm, we used CA(cellular automata)-based simulator and applied to different indoor distributions and presented the results.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.133-141
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• 1998

Terrain modelling is composed of a method using the rectangular grid and another using the triangulated irregular network. The method using the triangulated irregular network is most widely used because it can express the characteristics of the terrain well with only a small amount of information on the terrain and also reduces the rendering time. The process of extracting the surface-specific point and a triangular process is needed to construct such triangulated irregular network. This paper concentrates on the process of extracting the surface-specific point. The 8-direction neighborhood method and other transformed methods of the former method are frequently used to extract the surface-specific point. Another method which eliminates the unnecessary points using the Polygon reduction method is also suggested However, the 8-direction neighborhood method has a big fault of also drawing out some unnecessary points. To resolve such problem, we suggest a method of extracting the surface-specific point using the cross section of the terrain. This method reduces the time to extract the surface-specific point and enables a more precise extraction with less terrain information.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.13-20
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• 2012

In this study, the change pattern of hydrological response function as development has been observed. The target watershed was selected Tanbu sub-Basin in the Bocheong Basin. The applied channel networks are composed of 10 cases that are channel networks by strahler's ordering scheme and cases of all grids channel or the hillslope in basin. To each case of grid in basin, channel and hillslope drainage path lengths to outlet of basin are calculated, and hydrological response function was calculated by Nash Model. As results of this analysis, the peak discharge of hydrological response function is increased and peak time is shortened as development of channel networks. And based on statistical characteristics of hydrological response function, mean (lag time) and variance of travel time are reduced exponentially.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.85-92
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• 2013

This study determined the spatial distribution characteristics of carbon dioxide in Northeast Asia, connecting land coverage and vegetation index that have influence on concentration and distribution of carbon dioxide measured by GOSAT with GIS spatial analysis method. The results visibly showed that the spatial distribution of carbon dioxide had different patterns in dependent on the present status of land use in its surrounding area. Such high concentration of carbon dioxide was formed in developed sites like cities while forest areas showed low concentration of it. We also found that there were relatively high negative(-) correlations between carbon dioxide and vegetation, in statistically significant level. It is expected to be used as a basic data for establishing measures to reduce greenhouse gas in the future.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.39-47
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• 2017

Although motorcycle safety studies to date have identified the causes of motorcycle accidents in general, very few have investigated postal motorcycle accidents by studying the delivery postmen's specific work environment. To better understand postal motorcyclists' driving behavior associated with their delivery workload, we developed a system using V-World platform which visualizes driving behavior in real time along the driver's delivery route throughout an entire work day. We conducted a field test to examine the feasibility of our system by involving six delivery postmen currently working in Songpa, Seocheongju, and Gangseo, respectively. To show the potential of our system for nationwide comparison of postal motorcyclists' driving behavior and their workloads, we present several sample analyses using the collected field data. Although ideally, postmen's workloads should be standardized nationwide, we found large variation depending on regional characteristics of work area which affects postmen's driving behavior.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.195-203
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• 1996

The 3-D analysis of terrain for route design and selection is being used as important basic data for effective judgement of political draft. This study is to decide efficient alignment of the entry route and design bridge by modeling, analyzing and displaying surface with digital terrain data. In this study we analyze slope, aspect, shaded-relief, line of sight and watershed on the base of DTM such as contour, TIN and grid. And we can not only esti mate end-area volume for road construction by calculating cut and fill and displaying mass-curve but also recognize the scene after execution with simulation of road and terrain. The result of this study reveals that visual effects of the 3-D terrain data are very effective for designer and decisionmaker to select and review alternative route with regard to terrain characteristics.