• Journal of the Korean Geotechnical Society
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• v.28 no.4
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• pp.23-33
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• 2012

Recently, landslide disasters caused by severe rain storms and typhoons have been frequently reported. Due to the geomorphologic characteristics of Korea, considerable portion of urban area and infrastructures such as road and railway have been constructed near mountains. These infrastructures may encounter the risk of landslide and debris flow. It is important to evaluate the highly risky locations of landslide and to prepare measures for the protection of landslide in the process of construction planning. In this study, a landslide-risk prediction equation is proposed based on the statistical analysis of 423 landslide data set obtained from field surveys, disaster reports on national road, and digital maps of landslide area. Each dataset includes geomorphologic characteristics, soil properties, rainfall information, forest properties and hazard history. The comparison between the result of proposed equation and actual occurrence of landslide shows 92 percent in the accuracy of classification. Since the input for the equation can be provided within short period and low cost, and the results of equation can be easily incorporated with hazard map, the proposed equation can be effectively utilized in the analysis of landslide-risk for large mountainous area.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.139-150
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• 2007

As computer technology has been rapidly advanced, geographic information system (GIS) is recently used in many disciplines. In this study, for a model area in Seoul, seismic hazard potential relating to site effects, which are influenced by the subsurface geotechnical conditions, was estimated using the GIS tool. The distribution of pre-existing borehole drilling data in Seoul metropolitan area was examined for the regional estimation of site-specific seismic responses at the model area. Spatial geo-layers across the entire model area were predicted by constructing a GIS-based geotechnical information system (GTIS). A microzonation of site period $(T_G)$ for estimating site-specific seismic responses at the model area was performed within the GTIS. The spatial microzoning map of $T_G$ indicated seismic vulnerability of two- to four-storied buildings in the model area. Furthermore, a site classification map for determining the design ground motion was established based on the $T_G$ within the GTIS. This informed that most of location in the model area was categorized into current site classes C and D. This seismic microzonation framework for the model area could be applicable particularly in the entire Seoul metropolitan area based on the pre-existing borehole data.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.13-21
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• 2004

The dissemination of commercial satellite images. which have the high spatial resolution such as aerial photos, are the active trend in remote sensing community because of the recent development in satellite and sensor technology. Such high resolution satellite images provide a unique tool for the monitoring of ongoing urban land use change. Especially KOMPSAT-1, which was launched at December 1999 and successfully operated up to now, provides repeatedly panchromatic images over Korean peninsula, which has the spatial resolution of 6.6m. Based upon this KOMPSAT-1 EOC image data we can try to analyze and assess the temporal urban land use change, which could not be done because lack of such data. The aim of this paper is to analyze and assess the spatial land use characteristics of Daejeon Metropolitan City based on KOMPSAT-1 EOC data. The land use map of year 2001 is generated through the modification of the year 2000 land use map, which is published by National Geographic Information Institute, using visual interpretation of KOMPSAT-1 EOC image which is acquired in year 2001. This study can be the start point of the time series analysis of the long term land use change monitoring mit KOMPSAT-1 EOC data.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.1
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• pp.56-70
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• 2017

In this study, multi-image information for the central Taewha River basin was used to develop and analyze a distribution map of non-point pollution sources. The data were collected using a hyper-sensor (image), aerial photography, and a field spectro-radiometer. An image correction process was performed for each image to develop an ortho-image. In addition, the spectra from the field spectro-radiometer measurements were analyzed for each classification to create land cover and distribution maps of non-point pollutant sources. In the western region of the Taewha River basin, where most of the forest and agricultural land is distributed, the distribution map showed generated loads for BOD($kg/km^2{\times}day$) of 1.0 - 2.3, for TN($kg/km^2{\times}day$) of 0.06 - 9.44, and for TP($kg/km^2{\times}day$) of 0.03 - 0.24, which were low load distributions. In the eastern region where urbanization is in progress, the BOD, TN, and TP were 85.9, 13.69, and 2.76, respectively and these showed relatively high load distributions when the land use was classified by plot.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.911-922
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• 2012

This study aim that definite the relationship between coastal environment and different sand bar communities, as well as to analyze their spatial distribution of barrier island in the Nakdong river estuary. Survey method follow by Braun-Blanquet(1965) and there a total of 118 relev$\acute{e}$'s were undertaken. Definition of the relationships between species and environmental variables with Canonical Correlation Analysis(CCoA) and that to applied these relev$\acute{e}$'s with the RIM(Kim and Kim, 2006) program and that to classification used the SYN-TAX 2000 program(Podani 1979). On the basis of about 118 phytosociological releve's, the vegetation of xeric and hydric type was arranged in twelve plant communities: Xeric type-Pinus thunbergii community,Vitex rotundifolia community, Carex pumila community, Imperata cylindrica var. koenigii community, Miscanthus sacchariflorus community and Calystegia soldanella community, Hydric type-Salix dependens-Calamagrostis epigeios community, Calamagrostis epigeios-Phragmites communis community, Phragmites communis-Ischaemum aristatum community, Phragmites communis community, Scirpus planiculmis community and Suaeda glauca-S. japonica community.These plant communities represents sand dune vegetation and salt marsh vegetation. Widely distributing types in the actual vegetation map were sea club-rush community, reed community in salt marsh, and dry grassland. The edge in the coastal sand bars has zonation that almost distribution by the reed community in salt marsh. But outside of it were distributed sea club-rush community. Dry grassland type distributes higher zone of the center in coastal sand bars. Respectively, the coastal sand dune and salt marsh vegetation types were distributed ocean and inland on the frontier of it.

• Journal of the Korean association of regional geographers
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• v.13 no.3
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• pp.301-320
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• 2007

In Korean academic societies, old maps has not yet been properly investigated in terms of their genealogy, classification, detailed place names, historical backgrounds and the other aspects. With publication of the bibliographies and papers on old maps reserved in museum and library, the scope of research enlarged gradually its scope from 1970s. In 1980s, with the development of theoretical geography, scientific analysis were applied to investigate the projection method of Daedongyeo-jido. The 1990s proved a prominent decade for researches. The photo-copies of old maps enabled researchers to investigate the in-depth comparative study. The more important thing is that old maps became to be powerful instrument in the research of historical geography, such as territorial disputes and marine name(東海). And county old maps compiled by region became to be regional-cultural contents of local areas. Important issues in old map research in Korean academic societies are about Cheonha-do which is unique old world map in Korea, grid-system projection in old county maps and the genealogy of Daedongyeo-jido(manuscript and block print edition). This study shows that bibliography of all old maps preserved in each library and museum should be standardized. This could enable the exchange of information of old maps between institutes. The more important thing is that conciliation of human, social and natural sciences should be applied in the research of old maps.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.661-678
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• 2006

Products developed in this research is a software which can transfer the type of shape(.shp) into the type of ascii using the land cover data and the topography data in the metropolitan area of Seoul. In addition, it can calculate the $CO_2$ flux according to distribution of plants within the land cover data. The $CO_2$ flux is calculated by the experimental equation which is compose of the meteorological parameters such as the solar radiation and the air temperature. The net flux was shown in about $-19ton/km^2$ by removing $CO_2$ through the photosynthesis during daytime, and in 2 ton/km2 by producing it through the respiration during nighttime on 10 August 2004, the maximum day of air temperature during the period of 3yr(2001 to 2004), in the metropolitan area of Seoul. Spatial distribution of the air temperature and the wind field is simulated by substituting the middle classification of the land cover map data, upgraded by the Korean Ministry of Environment(KME), for the land-use data of the United States Geological Survey(USGS) within the Meteorological Mesoscale Model Version 5(MM5) on 10 August 2006 in the metropolitan area of Seoul. Difference of the air temperature between both data was shown in the maximum range of $-2^{\circ}C\;to\;2.9^{\circ}C$, and the air temperature due to the land use data of KME was higher than that of USGS in average $0.4^{\circ}C$. Also, those of wind vectors were meanly lower than that of USGS in daytime and nighttime. Furthermore, the hourly time series of Volatile Organic Components(VOCs) is calculated by using the Biosphere Emission and Interaction System Version 2(BEIS2) including the new land cover data and the meteorological parameters such as the air temperature and so]ar insolation. It is possible to calculate the concentration of ozone due to the biogenic emission of VOCs.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.1
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• pp.113-126
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• 2017

This study aimed to quantitatively analyze the trends in environmental research that utilize environmental geospatial information through text mining, one of the big data analysis technologies. The analysis was conducted on a total of 869 papers published in the Republic of Korea, which were collected from the National Digital Science Library (NDSL). On the basis of the classification scheme, the keywords extracted from the papers were recategorized into 10 environmental fields including "general environment", "climate", "air quality", and 20 environmental geospatial information fields including "satellite image", "numerical map", and "disaster". With the recategorized keywords, their frequency levels and time series changes in the collected papers were analyzed, as well as the association rules between keywords. First, the results of frequency analysis showed that "general environment"(40.85%) and "satellite image"(24.87%) had the highest frequency levels among environmental fields and environmental geospatial information fields, respectively. Second, the results of the time series analysis on environmental fields showed that the share of "climate" between 1996 and 2000 was high, but since 2001, that of "general environment" has increased. In terms of environmental geospatial information fields, the demand for "satellite image" was highest throughout the period analyzed, and its utilization share has also gradually increased. Third, a total of 80 correlation rules were generated for environmental fields and environmental geospatial information fields. Among environmental fields, "general environment" generated the highest number of correlation rules (17) with environmental geospatial information fields such as "satellite image" and "digital map".

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.525-532
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• 2021

In the ocean, it is difficult to separate the effects of one cause due to the multiple causes, but the self-organizing map can be analyzed by adding other factors to the cluster result. Therefore, in this study, the results of the clustering of sea level data were applied to sea surface temperature. Sea level data was clustered into a total of 6 nodes. The difference between sea surface temperature and sea level height has a one-month delay, which applied sea surface temperature data a month ago to the clustered results. As a result of comparing the mean of sea surface temperature of 140 to 150°E, where the sea surface temperature was variously distributed, in the case of nodes 1, 3, and 5, it was possible to find a meandering sea surface temperature distribution that is clearly distinguished from the sea level data. While nodes 2, 4 and 6, the sea surface temperature distribution was smooth. In this study, sea surface temperature data were applied to the clustered results of sea level data, but later it is necessary to apply wind or geostrophic velocity data to compare.

• Journal of Intelligence and Information Systems
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• v.28 no.3
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• pp.119-137
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• 2022

Recent recommendation system studies apply various deep learning models to represent user and item interactions better. One of the noteworthy studies is ONCF(Outer product-based Neural Collaborative Filtering) which builds a two-dimensional interaction map via outer product and employs CNN (Convolutional Neural Networks) to learn high-order correlations from the map. However, ONCF has limitations in recommendation performance due to the problems with CNN and the absence of side information. ONCF using CNN has an inductive bias problem that causes poor performances for data with a distribution that does not appear in the training data. This paper proposes to employ a Vision Transformer (ViT) instead of the vanilla CNN used in ONCF. The reason is that ViT showed better results than state-of-the-art CNN in many image classification cases. In addition, we propose a new architecture to reflect side information that ONCF did not consider. Unlike previous studies that reflect side information in a neural network using simple input combination methods, this study uses an independent auxiliary classifier to reflect side information more effectively in the recommender system. ONCF used a single latent vector for user and item, but in this study, a channel is constructed using multiple vectors to enable the model to learn more diverse expressions and to obtain an ensemble effect. The experiments showed our deep learning model improved performance in recommendation compared to ONCF.