• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.258-263
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• 2014

The purpose of this study is to provide basic data for forest roads management by using AHP methodology to group the grade of disaster risk. In addition to this, a field study was performed at 114 targeted points on forest roads where there are high risks of disaster occurrence. The results of the field survey and the analysis of AHP were compared to provide the degree of disaster risks. It shows that the drainage facilities occupied the highest weighted value. Meanwhile, based on AHP analysis data, evaluation chart was created by providing evaluation criteria and evaluation score to each evaluation items. As a result of applying the evaluation chart to the field survey data, the highest score was 78.8 and the lowest score was 42.7 with the mean score of 61.8. Finally, through the experts' consultation based on calculated scores, this study proposed four different groups of disaster risk on forest roads.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.3
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• pp.313-322
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• 2005

Rapid advances in technology and changes in human and cultural activities bring about changes to the earth surface in terms of spatial extension as well as time frame of the changes. Such advances introduce shorter updating frequency of maps and geospatial database. To satisfy these requirements, recent research efforts in the geoinformatics field have been focused on the automation and speeding up of the mapping processes which resulted in products such as the digital photogrammetric workstation, GPSIINS, applications of satellite imagery, automatic feature extraction and the LiDAR system. The possibility of automatically extracting buildings and generating contours from airborne LiDAR data has received much attention because LiDAR data produce promising results. However, compared with the manually derived building footprints using traditional photogrammetric process, more investigation and analysis need to be carried out in terms of accuracy and efficiency. On the other hand, generation of the contours with LiDAR data is more efficient and economical in terms of the quality and accuracy. In this study, the effects of various conditions of the pre-processing phase and the subsequent building extraction and contour generation phases for digital mapping have on the accuracy were investigated.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.69-74
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• 2004

By the expanding of infrastructure caused by urbanization, new technologies are required to manage various kinds of facilities. GIS has been appraised as valuable technology for facilities management since the 1990s. Therefore, the long and mid term GIS construction plan has been established by the national government and the local government. Some facilities management systems have been built and developed for suppling user-friendly functions. From this point of view, the information system based on the video sequences is considered a more effective way to improve the defects of conventional GIS using the digital map or the image as the base map. Using the video sequences as a base map, the availability of the system ill be increased because the real world information can be furnished to the users. In this study, through the connection between the GIS data, the digital map and the attribute data, and the video sequences taken from the airship using the video geo-referencing and the object tracking, we developed the facilities management system as a prototype which can effectively manage the road utilities. We also presented potentialities of the suggested system for facility management based on the video sequences.

• Spatial Information Research
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• v.21 no.1
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• pp.15-22
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• 2013

Recently, there are various attempts to construct a u-City and a smart city. A Spatial information as the city-based infrastructure has been recognized as an essential element. In many cases GIS data being lack of compatibility due to the various format, it is difficult to provide public web services and link the data between government organizations. In this study, we developed a interconnection Server based on OGC standardization to support interoperability in a heterogeneous distributed environment. we hope the interconnection server that will be utilized as u-City platform and response platform for volcanic disaster through the test in the test-bed.

• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.187-196
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• 2017

The use of unmanned aerial vehicles (UAV) for the estimation of tree height is gaining recognition. This study aims to assess the effectiveness of tree height estimation of Pinus densiflora Sieb. et Zucc. and Pinus koraiensis Sieb. et Zucc. using digital surface model (DSM) generated from UAV-acquired imageries. Images were taken with the $Trimble^{(R)}$ UX5 equipped with Sony ${\alpha}5100$. The generated DSM, together with the digital elevation model (DEM) generated from a digital map of the study areas, were used in the estimation of tree height. Field measurements were conducted in order to generate a regression model and carry out accuracy assessment. The obtained coefficients of determination (R2) and root mean square error (RMSE) for P. densiflora (R2=0.71; RMSE=1.00 m) and P. koraiensis (R2=0.64; RMSE=0.85 m) are comparable to the results of similar studies. The results of the paired two-tailed t-test show that the two tree height estimation methods are not significantly different (p-value=0.04 and 0.10, alpha level=0.01), which means that tree height estimation using UAV imagery could be used as an alternative to field measurement.

• Spatial Information Research
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• v.16 no.4
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• pp.385-400
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• 2008

This study investigates how Korean Land Spatialization Group (KLSG) has controlled and managed its own R&D effectively and what particular elements have made it practical. Korean Land Spatialization Program (KLSP) has produced large amounts of practical outcomes for the intelligent land by collaborative 5 core research projects. The well-harmonized cooperations between proving ground, practical business model, and services oriented integration and others have driven the KLSG to an succeedable management. The active role for practicality is prominent with its usefulness and competitiveness. KLSP is financially and administratively supported from Ministry of Land Transport and Maritime Affairs of Korea (MLTM). By investigating relationships between 5 core research projects involved in the R&D projects of KLSG, it has been found out that R&D projects of KLSG bring forth practicality and commercialization. The results of this study presents strategies of KLSP in conducting research for practicality and commercialization of GIS technology and integrated geospatial information.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.3 s.33
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• pp.87-94
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• 2005

3D positional information of lane can be automatically calculated tv combining GPS data, IMU data if coordinates of lane centers are given. The Road Safety Survey and Analysis Vehicle(RoSSAV) is currently under development to analyze three dimensional safety and stability of roads. RoSSAV has GPS and IMU sensors to get positional information of the vehicle and two road-facing CCD cameras for extraction of lane coordinates. In this paper, we develop technology that automatically detects centers of lanes from the road-facing cameras of RoSSAV. The proposed algorithm defines line-support regions by grouping pixels with similar edge orientation and magnitude together and extracts a line from each line support region by planar fitting. Then if extracted lines and the region in-between satisfy the criteria of brightness and width, we decide this region as lane. The proposed algorithm was more precise and stable than the previously proposed algorithm based on brightness threshold method. Experiments with real road scenes confirmed that lane was effectively extracted by the proposed algorithm.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.51-60
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• 2002

As the use of GIS becomes more widespread, the quality and source of data is becoming more of a concern among users. But accuracy is a component of quality, and the positional accuracy is a component of total accuracy. If only we consider the positional accuracy, simultaneously collecting technology of location and attribute information, whether it be manually, using conventional surveying method, GPS, or remote sensing, is a practical way of insuring that location and attribute information are correctly correlated. This study analyse the positional accuracy from a view-point of user and supplier, which is the considerations that can ensure quality level and continuously maintain the road and underground utility information. The positional accuracy of road and underground utility information are considered as two categories - expected accuracy of data collection procedure, required accuracy of data usage process. And the project manager must consider the cost/benefit view of data generation in order to determine the surveying method.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.69-76
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• 2002

Nowadays information is very important for Civil Engineering. This information is acquiredmostly via Surveying & Geo-spatial Information System. Also this information is close to the ITS(Intelligent Transformation System), Navigation, Facility Management, and Digital Mapping, etc and applicable to versatile fields from now on. And in surveying fields, GPS satellites are introduced newly and play a great rules. In this study, RTK(Real-Time Kinematic GPS), one of the positioning technology with GPS satellites, is used for the production of Plane Figure of Campus. The results shows that it is possible to extract the information for some part of a flowerbed and road, but not so for the buildings surrounded. Therefore this give occasion to the a lowering of work effectiveness over the total work-flow. So at such a time, it will be expected that the supplementary systems such TS(Total Station), Plane-table, and theodolite, etc have to be used.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.81-91
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• 2012

As the recent development of the ubiquitous computing environment, u-GIS is being highlighted as the core technology of the ubiquitous computing environment, and thereby, studies on spatio-temporal data are being actively conducted. In this u-GIS environment, it is still difficult for existing mobile devices to efficiently manage the massive spatio-temporal data of u-GIS that are increasing day by day. Therefore, this paper develops a spatio-temporal query processing system for mobile devices in order to solve the problem. The system provides various spatio-temporal operators to insert/delete/update/search spatio-temporal data and supports a query optimization function that uses a spatio-temporal index for the flash memory and a spatio-temporal histogram for guaranteeing query execution speed. Lastly, by applying the spatio-temporal query processing system developed in this paper to the virtual scenario, this paper has proved that the system can be utilized in various application fields necessary to process spatio-temporal data in the mobile environment.