• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.3
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• pp.233-238
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• 2005

3-D virtual city model is becoming increasingly important for a number of GIS applications. For reconstruction of 3D building in urban area aerial images, satellite images, LIDAR data have been used mainly and most of researches related to 3-D reconstruction focus on development of method for extraction of building height and reconstruction of building. In case of automatically extracting and reconstructing of building height using only aerial images or satellite images, there are a lot of problems, such as mismatching that result from a geometric distortion of optical images. Therefore, researches of integrating optical images and existing digital map (1/1,000) has been in progress. In this paper, we focused on extracting of building height by means of interest points and vertical line locus method for reducing matching points. Also we used digital plotter in order to validate for the results in this study using aerial images (1/5,000) and existing digital map (1/1,000).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.513-522
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• 2017

Rapid urbanization is being portrayed around the world au causing difficulty to manage public hygiene and maintain public order. Common problems often detected in urban areas including traffic congestion and the deterioration of the ecological environment are also being exacerbated. Despite all the effort being made by the government and local governments to manage urban facilities, urban residents are subjected to various levels of difficulty, due to the number of facilities to be managed exceeding the number of management personnel and the lack of an adequate management system. The aim of this study is to propose a management method using smart phones to improve the maintenance efficiency of urban facilities. First, the one-stop maintenance of urban facilities, including facilities information management, maintenance management and history management, is made possible by using smart phones to collect and transfer pictures and the locations of the urban facilities. Second, maintenance management is based on the location and picture information of the subject, not the location of the smart phones, which enables a prompt understanding of and actions to be taken for the facility. This method is especially effective as the smart phone application sends the facility status information directly to the maintenance personnel. Third, all of the information and figures relating to the facilities is managed using a database, resulting in the easy utilization of the history management and data. Fourth, all of the urban residents have access to this information via smart phone applications and, therefore, expanding the role of the facility maintenance personnel is made possible without any additional investment in infrastructure. Lastly, the location-based information enables the management of roads, trees and trails.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.400-409
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• 2016

The geospatial information industry has the advantage of being able to converge with other industries to create new value. Therefore, efforts are underway to promote the growth of this dwindling national industry by endorsing policies and initiatives to promote its convergence with other industries. In this study, feedback was collected from experts in various fields through three rounds of polls using the Delphi method. The poll results were used to investigate the causes of hindrance to the growth of the geospatial information industry and to build a comprehensive solution to this problem. As a result, 27 strategies were constructed based on the users' requirements related to policy, data and service, including the demands for establishing public polling methods, enhancing data quality and advertisement. Since the coefficient of variance fell between 0.11 and 0.20 in the importance evaluation, an amicable consensus was reached between the experts. Considering that the convergence of industries is achieved through the integration of various types of technology and information, it is important to consider the requirements of users in different industries. In this respect, the results of this study will serve as a useful base for constructing mid-to-long term road maps to promote the development of the geospatial information industry.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.2
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• pp.81-90
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• 2002

Remote Sensing has been very useful tool in monitoring of cities and updating of GIS database compare to traditional methods due to its benefit; wide range covering on low cost and advanced data collection. However it had come to a limited method in limited researches because of its relatively poor spatial resolution in scanning. Recently launched satellites are able to produce improved imageries, and new commercial services have been commenced for the use of general public with higher spatial resolution up to $1m{\times}1m$. This study tackled a potential use of these improved satellite imageries in urban planning based on the Multi-temporal satellite imagery with particular reference to monitoring on urban areas, for example urbanization and its expanding. i) Portion of individual features and elements in each pixel of satellite imagery was computed based on 'Endmember' of targeted elements. ii) Urbanized areas were categorized based on the 'Fraction imagery' derived from the 'SMA algorithm'. iii) Alterations and expanding of urban areas were identified based on the Multi-temporal satellite imageries. Tested method showed a strong potential to produce more advanced monitoring skills of urban areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.86-100
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• 2014

The purposes of this study are to provide a guideline for the suitability of wind farm facilities in forest lands and to suggest improvement plans of policies and systems to minimize the damage of forest lands. First, we implemented a literature review and field surveys to examine and select factors for the suitability of wind farm facilities in forest lands. Spatial database for selected location factors of wind farm facilities in forest lands was constructed to develop the suitability model for locating wind farm facilities focusing on Gangwon-do. Data used in this study include wind power resource, legal mountainous preserved area, forest roads, developed areas, forest class, and other spatial data. In order to find specific-sized potential areas for a certain number of wind farm turbines, we used block statistics and focal statistics methods. As a result, the areas for potential wind farm locations were 1,261ha from a block statistics method and 1,411ha from a focal statistics method. Based on the outputs of this research, it is required to make an urgent solution for the prevention of forest disaster and to prepare reduction measures for the destruction of ridge landscape.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.194-204
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• 2007

The purpose of this paper was to propose a Topographic Position Index(TPI) method for predicting forest wetlands, and also to test the suitability of the predicted forest wetlands by comparing with the existing wetlands in Ulaju-gun and Gyengsangnam-do. A prediction of the spatial distribution of forest wetlands was accomplished by TPI grids from Digital Elevation Model(DEM), and the classification results of slope position and landform categories in study area using the TPI values. According to the results of predicting forest wetlands distribution by TPI method, the predicted area in case of less than $5^{\circ}$ flat slope criteria occupied 0.1%($1.38km^2$) of the total area, and 3.5%($37.1km^2$) of total area in below $10^{\circ}$ slope criteria. According to the results of the suitability analysis by comparing the predicted area with the existing forest wetlands, the suitability value (0.066) of the predicted area with less than $10^{\circ}$ flat slope criteria was the highest, but the predicted area in case of less than $20^{\circ}$ had the lowest value(0.019).

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.2
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• pp.32-46
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• 2017

Recent rapid urban expansion and crowding of various industrial facilities has affected the features of a significant part of downtown area, resulting in areas having buildings with a wide range of height and the foothills. To compute a velocity pressure exposure coefficient, namely the design wind speed factor, this study defines ground surface roughness by utilizing concentration analysis for the height of each building. After obtaining spatial data by extracting a building layer from digital maps, the study area was partitioned for the concentration analysis and to allow investigation of the frequency distribution of building heights. Concentration analysis by building height was determined with the Variation-to-Means Ratio (VMR) and Poisson distribution analysis using a buildings distribution chart, with statistical significance determined using Chi-square verification. Applying geographic information systems (GIS) with the architectural information made it possible to estimate a velocity pressure exposure coefficient factor more quantitatively and objectively, by including geographic features, as compared to current methods. Thus, this method is expected to eliminate inaccuracies that arise when building designers calculate the velocity pressure exposure coefficient in subjective way, and to help increase the wind resistance of buildings in a more logical and cost-effective way.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.547-557
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• 2012

This study purposed to estimate the forest biomass using k-Nearest Neighbor (k-NN) algorithm. Multiple data sources were used for the analysis such as forest type map, field survey data and Landsat TM data. The accuracy of forest biomass was evaluated with the forest stratification, horizontal reference area (HRA) and spatial filtering. Forests were divided into 3 types such as conifers, broadleaved, and Korean pine (Pinus koriansis) forests. The applied radii of HRA were 4 km, 5 km and 10 km, respectively. The estimated biomass and mean bias for conifers forest was 222 t/ha and 1.8 t/ha when the value of k=8, the radius of HRA was 4 km, and $5{\times}5$ modal was filtered. The estimated forest biomass of Korean pine was 245 t/ha when the value of k=8, the radius of HRA was 4km. The estimated mean biomass and mean bias for broadleaved forests were 251 t/ha and -1.6 t/ha, respectively, when the value of k=6, the radius of HRA was 10 km. The estimated total forest biomass by k-NN method was 799,000t and 237 t/ha. The estimated mean biomass by ${\kappa}NN$method was about 1t/ha more than that of filed survey data.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.27-34
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• 2013

Due to the increased interest in global warming, interest in forest resources aimed towards reducing greenhouse gases have subsequently increased. Thus far, data related to forest resources have been obtained, through the employment of aerial photographs or satellite images, by means of plotting. However, the use of imaging data is disadvantageous; merely, due to the fact that recorded measurements such as the height of trees, in dense forest areas, lack accuracy. Within such context, the authors of this study have presented a method of data processing in which an individual tree is isolated within forested areas through the use of LIDAR data and ortho-images. Such isolation resulted in the provision of more efficient and accurate data in regards to the height of trees. As for the data processing of LIDAR, the authors have generated a normalized digital surface model to extract tree points via local maxima filtering, and have additionally, with motives to extract forest areas, applied object oriented image classifications to the processing of data using ortho-images. The final tree point was then given a figure derived from the combination of LIDAR and ortho-images results. Based from an experiment conducted in the Yongin area, the authors have analyzed the merits and demerits of methods that either employ LIDAR data or ortho-images and have thereby obtained information of individual trees within forested areas by combining the two data; thus verifying the efficiency of the above presented method.

• Journal of Korea Water Resources Association
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• v.42 no.5
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• pp.397-406
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• 2009

River is able to change by various environmental factors. In order to conduct restoration design of abandoned river channels, it is necessary to evaluate the river through the analysis of past and present river channels. River evaluation requires various data, such as geometry, hydraulic and hydrology, but there is a lot of difficulty to understand topographical information of river change on time and space due to a lack of past data by domestic conditions. This study analyzes the changes in past and present river channels and examines the applicability of river channel evaluation through image analysis using aerial photographs and 1918 year's map. Aerial photograph analysis was conducted by applying the image analysis method and GIS analysis method on Cheongmicheon. As a result of this analysis, we have quantitatively identified the form and size of abandoned channels, changes in the vertical-section and cross-section length of rivers, and micro-landform changes. More importantly, we verified that morphological changes in sandbars due to artificial straightening are important data in identifying the state of current river channels. In these results, although image analysis technique has limitations in two-dimensional information from aerial photographs, we were able to evaluate the changes in river channel morphology after artificial maintenance of the river.