• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.621-626
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• 2006

Today's commercial high resolution satellite imagery such as IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Extraction of 3D building information from high resolution satellite imagery is one of the most active research topics. There have been many previous works to extract 3D information based on stereo analysis, including sensor modelling. Practically, it is not easy to obtain stereo high resolution satellite images. On single image performance, most studies applied the roof-bottom points or shadow length extracted manually to sensor models with DEM. It is not suitable to apply these algorithms for dense buildings. We aim to extract 3D building information from a single satellite image in a simple and practical way. To measure as many buildings as possible, in this paper, we suggested a new way to extract building height by triangular vector structure that consists of a building bottom point, its corresponding roof point and a shadow end point. The proposed method could increase the number of measurable building, and decrease the digitizing error and the computation efficiency.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.89-96
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• 2005

As the number of the municipalities which have finished the phase I of their GIS system development projects increases, it is very natural that GIS system operation and maintenance rather than development itself has been a more important concern for these municipalities. It seems to me that these phenomena will be amplified as time goes by, and this is the right time for a series of proper guidelines regarding the GIS system maintenance to be supplied to the related municipalities. The subject which is called as 'GIS maintenance' is surely a very comprehensive area. It has been also founded that the necessity is widely agreed among the concerned people working for the municipalities which have already finished their first GIS projects. Nevertheless, it has been investigated that the studies done up to now in this area is in a very infant state from the quality and also quantity points of views. This paper, therefore, makes one of the very initial trials for the systematical GIS maintenance. Among the areas of GIS maintenance, the GIS database maintenance has been selected as the first trial area because of its natural characteristics of the basic element composing IS(Information System). For this, the present conditions of a variety of municipalities have been investigated as far as GIS maintenance is concerned, and the results are analyzed to produce a series of useful outcomes in terms of facing problems and accompanied plans. For each problem, a solution is defined and for each solution a detailed action plan (item) is derived. For each of the two kinds of GIS data given which are the fundamental map and the underground facilities map, an effective GIS data maintenance plan is suggested for the concerned municipalities.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.3
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• pp.209-215
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• 2005

Conventional ORDBMS vendors provide extension mechanisms for adding user-defined types and functions to their own DBMSs. Here, the extension mechanisms are implemented using a high-level interface. We call this technique loose-coupling. The advantage of loose-coupling is that it is easy to implement. However, it is not preferable for implementing new data types and operations in large databases when high Performance is required. In this paper, we propose to use the notion of tight-coupling to satisfy this requirement. In tight-coupling, new data types and operations are integrated into the core of the DBMS engine. Thus, they are supported in a consistent manner with high performance. This tight-coupling architecture is being used to incorporate information retrieval(IR) features and spatial database features into the Odysseus/IR ORDBMS that has been under development at KAIST/AITrc. In this paper, we introduce Odysseus/IR and explain its tightly-coupled IR features (U.S. patented). We then demonstrate a web search engine that is capable of managing 20 million web pages in a non-parallel configuration using Odysseus/IR.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.55-67
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• 2023

This study aims to develop a model that can automatically identify the rooftop shape of apartment buildings using GIS and machine learning algorithms, and apply it to analyze the relationship between rooftop shape and characteristics of apartment complexes. A database of rooftop data for each building in an apartment complex was constructed using geospatial data, and individual buildings within each complex were classified into flat type, tower type, and mixed types using the random forest algorithm. In addition, the relationship between the proportion of rooftop shapes, development density, height, and other characteristics of apartment complexes was analyzed to propose the potential application of geospatial information in the real estate field. This study is expected to serve as a basic research on AI-based building type classification and to be utilized in various spatial and real estate analyses.

• Journal of Korea Spatial Information System Society
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• v.9 no.1
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• pp.105-115
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• 2007

Data mining extracts interesting knowledge from a large database. Among numerous data mining techniques, research work is primarily concentrated on clustering and association rules. The clustering technique of the active research topics mainly deals with analyzing spatial and attribute data. And, the technique of association rules deals with identifying frequent patterns. There was an advanced apriori algorithm using an existing bit-clustering algorithm. In an effort to identify an alternative algorithm to improve apriori, we investigated FP-Growth and discussed the possibility of adopting bit-clustering as the alternative method to solve the problems with FP-Growth. FP-Growth using bit-clustering demonstrated better performance than the existing method. We used chess data in our experiments. Chess data were used in the pattern mining evaluation. We made a creation of FP-Tree with different minimum support values. In the case of high minimum support values, similar results that the existing techniques demonstrated were obtained. In other cases, however, the performance of the technique proposed in this paper showed better results in comparison with the existing technique. As a result, the technique proposed in this paper was considered to lead to higher performance. In addition, the method to apply bit-clustering to GML data was proposed.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.45-53
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• 2013

Global warming causes sea levels to rise and global changes apparently taking place including coastline changes. Coastline change due to sea level rise is also one of the most significant phenomena affected by global climate change. Accordingly, Coastline change detection can be utilized as an indicator of representing global climate change. Generally, Coastline change has happened mainly because of not only sea level rise but also artificial factor that is reclaimed land development by mud flat reclamation. However, Arctic coastal areas have been experienced serious change mostly due to sea level rise rather than other factors. The purposes of this study are automatic extraction of coastline and identifying change. In this study, in order to extract coastline automatically, contrast of the water and the land was maximized utilizing modified NDWI(Normalized Difference Water Index) and it made automatic extraction of coastline possibile. The imagery converted into modified NDWI were applied image processing techniques in order that appropriate threshold value can be found automatically to separate the water and land. Then the coastline was extracted through edge detection algorithm and changes were detected using extracted coastlines. Without the help of other data, automatic extraction of coastlines using LANDSAT was possible and similarity was found by comparing NLCD data as a reference data. Also, the results of the study area that is permafrost always frozen below $0^{\circ}C$ showed quantitative changes of the coastline and verified that the change was accelerated.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.89-101
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• 2016

This study examined spatial disposition of wildlife highway mortality using road-kill GIS database and Naver panoramic 360 degree views to find out which habitat and road variables most influenced road-kill numbers for each mammal species and how the landscape and road elements are connected on highway. Road-kills on Yeongdong(YD) and Jungbu highway(JB) generally tended to be higher in natural barren, grassland and cropland due to its value of preferred habitats of nocturnal and multihabitat species like water deer(Hydropotes inermis argyropus), raccoon(Nyctereutes procyonoides) and hare(Lepus coreanus). Land cover in YD showed no difference between species (p=0.165) while JB did by species (p=0.001). This may be explained by disparate landscape between mountain and urban or the fact that YD in long term operation might have enabled consistent crossing pattern compared to JB experiencing continuous extension works which may in turn have deviated the road crossing. Although road-kill prevention effect of local topography alone was appreciable, compared to less significant or ineffective fence and guardrail, gentle slope declining in a direction to the road turned out to offset the preventive effect of juxtaposed fence. Furthermore, green patches on road near intersection were deemed a visual stepping stone facilitating wildlife attempted crossing and local roads juxtaposed with a highway were especially left defenceless to road-kill without road barriers.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.661-675
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• 2009

The carelessly and illegally copied contents are raising serious social problem as internet and multimedia technologies are advancing. Therefore, development of video copy detection system must be settled without delay. In this paper, we propose the hierarchical video copy detection method that estimates similarity using statistical characteristics between original video and manipulated(transformed) copy video. We rank according to luminance value of video to be robust to spacial transformation, and choose similar videos categorized as candidate segments in huge amount of database to reduce processing time and complexity. The copy videos generally insert black area in the edge of the image, so we remove rig black area and decide copy or not by using statistical characteristics of original video and copied video with center part of frame that contains important information of video. Experiment results show that the proposed method has similar keyframe accuracy to reference method, but we use less memory to save feature information than reference's, because the number of keyframes is less 61% than that of reference's. Also, the proposed method detects if the video is copied or not efficiently despite expansive spatial transformations such as blurring, contrast change, zoom in, zoom out, aspect ratio change, and caption insertion.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.1 s.39
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• pp.39-46
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• 2007

Most areas in Kangwon Province are mountainous and vulnerable to landslide due to the rainy season in summer and the localized torrential downpour triggered by abnormal climate. In particular, the rainfall is one of direct reasons for landslide. In accordance with the analysis of the relevance between the landslide areas and the accumulated rainfall for four months, there are severe damages of landslide to the areas having more than 1,100 mm of rainfall during three(3) months. Further, it indicates that the more the accumulated rainfall is the greater the size of landslide. These analyses show that the rainfall causes the possible and potential landslide in the vulnerable areas. And also, it means that there exist strong possibilities of landslide even in the areas of lower vulnerability if the amount of rainfall is above certain standard level. Accordingly, in this study we stored the GIS database on the causes and factors of landslide in the southern parts of Kangwon province and conducted simulations on the change of distribution of vulnerable areas by varying the rainfall conditions and by using the evaluation data of landslide vulnerability. As such a result, we found that the landslide could potentially occur if the amount of rainfall is 200 mm and more.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.4
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• pp.13-22
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• 2009

Urban expansion has caused environmental problems, traffic jam and real estate. Trend analysis of Urban expansion is needed for analysis and prediction of the existing problem-solving, urban planning and land use. In this study, We constructed database based on MOE(Minister of environment)'s landcover(1980's, 2000's), 1: 25,000 digital topographical map using of DEM and data of the National Statistical Office for urban and build up expand analysis of South Korea. As a result, The rate of increase in population of Gyeonggi-do, Incheon and Ulsan are high but Jeollanam-do is low. Area of development zone was 2.15 fold increase in comparison with before it. Slope aspect is south or east and urban expansion was increase in district such as Chungcheongnam-do, Gyeonggi-do, Jeollanam-do. Existing road of accessibility was high than development zone. Metropolitan city developre it. In conclusion, we found that South Korea urban expansion was developed from metropolitan city. In natural topographical conditions, the development was progress advantageous zone to disadvantageous zone. Also, we found that population was rapidly increase with new development as the center zone in urban expansion zone.