• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.105-117
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• 1998

The main object of this study was to prove the effectiveness of satellite Image data for extraction of the pine needle gall midge damaged area in the part of Kangwon-do area, and to present the detailed procedure of a digital image processing for extraction of those damaged area. The effectiveness of extraction of damaged area was improved by using the BRCT(Backwards Radiance Correction Transformation) with DEM for the normalization of topographic effects. The topographic surface analysis of the extracted damaged area revealed that the general damaged area was at south-west and south-east aspect with the slope of 31 to 38 degrees, the temperature of 21 to 25, and 23% to 39% of the highest altitude mountains. The new damaged area in which expanded area was at 27 to 30 degree of slope, the aspect of 46 to 180 degrees, the temperature of $11^{\circ}C\;to\;12^{\circ}C$ and 27% to 39% of the highest altitude mountains. The NDI(New Damaged Index) was developed using the environment factor and simple vegetation index.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.2 s.40
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• pp.59-66
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• 2007

The digital working environment and its related technology have been rapidly expanding. In the surveying field, we have changed from using optical film cameras and plotters to digital cameras, multi sensors like GPS/INS etc,. The old analog work flow is replaced by a new digital work flow. Accurate data of the land is used in various fields, efficient utilization and management of land, urban planning, disaster and environment management. It is important because it is an essential infrastructure. For this study, LiDAR surveying was used to get points clouds in the study area. It has a high vegetation penetrating advantage and we used a digital process from planning to the final products. Contour lines were made from LiDAR data and compared with national digital base maps (scale 1/1,000 and 1/5,000). As a result, the accuracy and the economical efficiency were evaluated. The accuracy of LiDAR contour data was average $0.089m{\pm}0.062\;m$ and showed high ground detail in complex areas. Compared with 1/1,000 scale contour line production when surveying an area over $100\;km^2$, approximately 48% of the cost was reduced. Therefore we prepose LiDAR surveying as an alternative to modify and update national base maps.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.43-51
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• 2012

Due to the increasing demand to utilize water fronts and water resource effectively, a multi-dimensional model that provides detailed hydraulic characteristics is required in order to improve the decision making process. An EFDC model is a kind of multi-dimension model, and it requires detailed 3D (3-dimensional) terrain in order to simulate the hydraulic characteristics of stream flow. In the case of 3D terrain creation, especially river reaches, measurement resolution and spatial interpolation methods affect the detailed 3D topography which uses input data for EFDC simulation. Such results make hydraulic characteristics to be varied. This study aims to examine EFDC simulation results depending on the 3D topographies derived by separate measurement resolution and spatial interpolation methods. The study area is at the confluence of the Nakdong and Kuemho Rivers and the event rain implemented was Typhoon Ewiniar in 2006. As a result, in the case of the area-elevation curve, the difference by means of the interpolation methods was significant when applying the same measurement resolution, except at 160m resolution. Furthermore, when the measurement resolution was 80m or above, the difference in a cross-section was occurred. Meanwhile, the water level changes between interpolation methods were insignificant by the measurement resolution except when the Kriging method was used for the 160m measurement data. Velocity changes emerged according to the interpolation methods when measurement resolution was 80m or above and the Kriging method resulted in a velocity that had a considerable gap in relation to the results from other methods at a measurement resolution of 160m.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.103-109
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• 2007

Ortho images and Digital Elevation Model (DEM) have been applied in various fields. It is necessary to acquire Ground Control Points (GCPs) for processing high resolution satellite images. However surveying GCPs require many time and expense. This study was performed to investigate whether GCPs automatically extracted from ortho images and DTED Level 2 can be applied to sensor modeling for high resolution satellite images. We analyzed the performance of the sensor model established by GCPs extracted automatically. We acquired GCPs by matching satellite image against ortho images. We included the height acquired from DTED Level 2 data in these GCPs. The spatial resolution of the DTED Level 2 data is about 30m. Absolution accuracy of this data is below 18m above MSL. The spatial resolution of ortho image is 1m. We established sensor model from IKONOS images using GCPs extracted automatically and generated DEMs from the images. The accuracy of sensor modeling is about $4{\sim}5$ pixel. We also established sensor models using GCPs acquired based on GPS surveying and generated DEMs. Two DEMs were similar. The RMSE of height from the DEM by automatic GCPs and DTED Level 2 is about 9 m. So we think that GCPs by DTED Level 2 and ortho image can use for IKONOS sensor modeling.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.1
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• pp.53-64
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• 2013

Since 2000, ubiquitous cities are spread over Korea by government's supporting project for ubiquitous city construction. But recently problems such as low perception of ubiquitous city are issued. There is just a few studies about a creation of citizen centric ubiquitous city service even though there have been several studies and policies to overcome such problems. There is not enough research on applying ubiquitous city service effectively at the stage of ubiquitous city plan. To solve this problems, this study ultimately aims to suggest essential ubiquitous city service applied at that stage to guarantee minimum quality of ubiquitous city. The expert survey method was employed to select essential ubiquitous city service. To achieve this goal, First, a survey performed by 163 local government officers to know current status of the ubiquitous city construction project. Second, another survey was performed for about 30 days by 38 experts worked at local public official and ubiquitous city organization to select essential ubiquitous city service. Finally we suggested 14 essential ubiquitous city service from the several viewpoints, which were universality, industry growth, social welfare, effective city management. And we analyzed the differences between ubiquitous city services written 14 ubiquitous city plan and essential ubiquitous city services.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.1
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• pp.19-26
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• 2013

This study analyzed the vulnerable areas to the fire service in regard to 119 safety centers, currently established in Jinju city. In this study, the district of fire was examined through the analysis of the OD cost matrix to find the transference or increase methods of the existing centers for improving the fire services. The study results demonstrate that the numbers of 119 safety centers were lacking in comparison with the areas of the administrative district in Jinju. In particular, relocation and the transference or increase of centers were required for the Cheonjeon 119 safety centers, which is the creation area of the National Industrial Complex among five 119 safety centers located in Jinju, and the fire service jurisdiction of Munsan 119 safety centers (including Banseong 119 regional unit), which is the location of a big fire risk due to the increase of population according to the development of the new town. In addition, the OD cost matrix analysis in this study reveals the fact that the time of fire service in the Jeonchon Industrial Complex, which is the significantly vulnerable area, will be reduced from 8 minutes to 3.3 minutes if the current Cheonjeon 119 safety center is moved to Gaho-dong. It indicates that the increase of safety centers in Geumsan-myeon areas, where the population has increased rapidly in recent days due to the development of the new town, is keenly needed.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.71-83
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• 2013

Recently frequencies and scales in natural disasters have been significantly increased and enlarged and that leads to increase interests on preventing disasters. As natural disasters occur, it is difficult to fulfill the scale of natural disasters using ordinary stocks in a local government. Thus, it is necessary to establish a system that commonly uses protection resources according to regional characteristics in order to rapidly implement labor mobilization and equipment distribution based on the damage of natural disasters. In this study, regional characteristics in Korea provinces are analyzed and 'a way of composing a local government consortium for common disaster responses' is proposed. First, a disaster map that represents the amount of damage for each local government published in the disaster yearbook from 2002 to 2011 is produced using GIS. Then, the whole land is divided into five different sections according to administrative regions and that are divided into 12 clusters again based on the geographical and humanistic characteristics and the analysis of the scale of damage in typhoons and heavy rainfalls. Finally, disaster protection base stations for each region are selected. The data of analyzing disaster damages may be used as a reference material for establishing disaster prevention plans.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.13-19
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• 2017

This paper analyzed MODIS data from 2006 to 2013 to determine relationship between meteorological changes and vegetation index. The experimental area was divided into the northern, central and southern regions according to the regional characteristics, and the smoothed MODIS LAI and NDVI were obtained using Timesat. In the case of precipitation, MODIS NDVI had correlation coefficients of 0.66, 0.44 and 0.35 in the northern, central and southern regions and the correlation was the highest in the northern region. In the case of temperature, MODIS LAI had correlation coefficients of 0.66, 0.64 and 0.68, and MODIS NDVI had 0.89, 0.89 and 0.80. The correlation of MODIS NDVI was higher and showed similar positive correlation regardless of region. In addition, The accuracy between Timesat plant seasonal start and actual plant seasonal start in MODIS NDVI was higher than MODIS LAI. The average error in MODIS LAI was 19 days in the central region and 20 days in the southern region. And the average error in MODIS NDVI was 6 days in the central region and 8 days in the southern region.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.67-74
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• 2017

The D-InSAR is a technique for precisely measuring the subsidence of subsidence using difference of two SAR images. In order to calculate the subsidence using D-InSAR, a high coherence between master image and the slave image is essential. Since the existing D-InSAR method calculates the displacement based on the total coherence, the accuracy of the subsidence is lowered when the coherence map contains mountains or bare-land. In order to solve this problem, in this study, a point having a temporal coherence and spatial coherence of 0.7 or more was extracted to form TIN, and the subsidence was calculated based on this TIN. In addition, we compared the existing D-InSAR technique with the new D-InSAR technique considering spatial and temporal coherence. As a result, the new D-InSAR technique showed smaller standard deviation, relative variance, variation coefficient and quadrature deviation than the existing D-InSAR technique. It is also easy to grasp the trend of the subsidence.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.2 s.32
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• pp.13-20
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• 2005

Upon the request of balanced development of the country and making inroads into the continent of China the development of the west coast was begun in the late 1980s, which has been being continued till recently under the blueprint of making the western part of the capital region to be the hub of northeastern Asia. As more lively development is expected to continue in the area, there are many occurrences of change in topology and terrain in the west coast. This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using landsat images. The accuracy of the images was examined by comparing them with GCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From the results, it was concluded that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land, and the area of agriculture and downtown increased, the drainage and bare land area decreased by comparing the change of land use.