• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.349-350
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• 2023

In the field of domestic construction, 3D modeling mainly targets outdoor construction sites, and acquires outdoor spatial information by operating UAVs and UGVs equipped with cameras. 3D modeling of construction sites tends to expand its scope to indoors along with the increasing demand for site monitoring and management through indoor spatial information. In the case of indoors, it is impossible to shoot with a drone after the framework and outer walls of the building are completed, so it is necessary to collect indoor spatial information and 3D modeling using a 360 camera. The purpose of this study is limited to basic research to establish a process that can obtain simple and high-quality indoor 3D modeling results using indoor data collected from 360 cameras.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.360-373
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• 2017

This paper presents a novel digital video steganalysis scheme against the spatial domain video steganography technology based on a spatial temporal detector (ST_D) that considers both spatial and temporal redundancies of the video sequences simultaneously. Three descriptors are constructed on XY, XT and YT planes respectively to depict the spatial and temporal relationship between the current pixel and its adjacent pixels. Considering the impact of local motion intensity and texture complexity on the histogram distribution of three descriptors, each frame is segmented into non-overlapped blocks that are $8{\times}8$ in size for motion and texture analysis. Subsequently, texture and motion factors are introduced to provide reasonable weights for histograms of the three descriptors of each block. After further weighted modulation, the statistics of the histograms of the three descriptors are concatenated into a single value to build the global description of ST_D. The experimental results demonstrate the great advantage of our features relative to those of the rich model (RM), the subtractive pixel adjacency model (SPAM) and subtractive prediction error adjacency matrix (SPEAM), especially for compressed videos, which constitute most Internet videos.

• Journal of Cadastre & Land InformatiX
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• v.52 no.2
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• pp.103-119
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• 2022

The purpose of this study is to propose a plan to establish a system that can maximize the effectiveness of disaster safety training. A review of previous studies and analysis of current status cases was conducted to examine the current level of data, systems, demand technologies, laws, and systems for related fields. A disaster safety training system linking digital twin and extended reality technology was proposed, and a study on the construction plan was conducted for this. It is hoped that the results of this study can contribute to the advancement of the disaster safety training system and reduce disaster damage.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.29-40
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• 2012

The method regarding obtaining various kinds of attribute data of spatial information, including that of digital map, is normally restricted to Geographic survey that deals with in-field surveys. Geographic surveying for drawing digital map, however, require much effort due to the fact that a surveyor has to characterize geographic features individually in the field. Not only does the Geographic survey cover large area, but also its need for manual drawing and surveying using Draft map makes it more expensive and time-consuming. Though some recent Geographic surveys take advantage of MMS(Mobile Mapping System) to collect computerized information, there are inevitable limits in creating digital map with such data. This research will analyze the problems in current Geographic surveys and suggest adequate methods and standards for Geographic surveys by researching the methods of domestic/international service organizations that deal with establishing spatial information. This study therefore will aim to enhance the efficiency of creating digital map and Geographic survey, which would ultimately maximize the applicability of pan-national digital map by improving reliability of digital map and upgrading the utilizability of Geographic survey data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.27-36
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• 2003

Generally, the latest acquisition method of geo-spatial informations in urban area is executed by generation of digital elevation model (DEM) and digital ortho image by digital photogrammetry method which is used large scale photo image. However, the biggest problem of this method is coarse accuracy of DEM which is automatically generated by digital photogrammetry workstation system. The coarse accuracy of DEM caused geo-spatial information in urban area to reduce of accuracy. Therefore, this study is purposed to increase of DEM accuracy which is applied to method terrain classification in urban area. As the results of this study, the proposed method of this study which is increased to accuracy of DEM by classification of terrain is better than accuracy of DEM which is automatically generated by digital photogrammetry workstaion system. And, the edge detection method which is proposed by this study is established to capability of 3D digital mapping in urban area.

• ETRI Journal
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• v.41 no.3
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• pp.277-288
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• 2019

VWorld is run by the Ministry of Land, Infrastructure, and Transport of South Korea and provides national spatial information, such as aerial images, digital elevation models, and 3D structural models. We propose herein an open platform for 3D spatial information based on WebGL using spatial information from VWorld. WebGL is a web-based graphics library and has the advantage of being compatible with various web browsers. Our open platform is also compatible with various web browsers. Accordingly, it is easily accessible via the VWorld site and uses the three-dimensional (3D) map program. In this study, we describe the proposed platform configuration, and the requests, management, and visualization approaches for VWorld spatial information data. Our aim is to establish an approach that will provide a stable rendering speed even on a low-end personal computer without a graphics processing unit based on a quadtree structure. We expect that users will be able to visualize 3D spatial information through the VWorld open platform, and that the proposed platform will become the basis for various applications.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.45-56
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• 2010

This paper suggests constraint data modeling based on constraint data presentation techniques to perform complex spatial database operation naturally. We were able to identify the limitation of extendibility of dimension and non-equal framework via relevant research for former schema of spatial database and query processing. Therefore we described generalized tuple of spatial data and the definition of suggested constraint data modeling. Also we selected MLPQ/PReSTO tool among constraint database prototype and compare standard functionality of ARC/VIEW. Then we design scenario for spatial operation using MLPQ/PReSTO and we suggested application effect after query processing. Based on above explanation, we were able to identify that we can process spatial data naturally and effectively using simple constraint routine on same framework via constraint data modeling.

• Spatial Information Research
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• v.7 no.1
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• pp.119-131
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• 1999

Various digital topographic maps including 1:1,000 and 1:5,000 have been produced for years and these digital maps are expected to serve a wide range of purposes. Most previous research about measuring positional accuracy for digital topographic maps depends int a method that acquires sample points from the tested map and compares to the corresponding known true locations using some statistics. Recently, a simple method for measuring positional accuracy for linear features is introduced but it has substantial problems applying to the spatial features such as roads, railroads, streams represented with double lines on the recently produced 1:1,000 and 1:5,000 digital topographic maps. This study develops and implements an effective method that measures road objects represented in the 1:5,000 digital topographic maps using a conventional GIS software. We also apply this method to a small study area located in Kangnam Gu, Seoul and illustrate the usefulness of this method.

• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.97-104
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• 2016

In this paper, we propose spatial information based simulator for user experience optimization and minimize real space complexity. We focus on developing simulator how to design virtual space model and to implement virtual character using real space data. Especially, we use expanded events-driven inference model for SVM based on machine learning. Our simulator is capable of feature selection by k-fold cross validation method for optimization of data learning. This strategy efficiently throughput of executing inference of user behavior feature by virtual space model. Thus, we aim to develop the user experience optimization system for people to facilitate mapping as the first step toward to daily life data inference. Methodologically, we focus on user behavior and space modeling for implement virtual space.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.385-392
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• 2010

A LiDAR technique has the merits that survey engineers can get a large number of measurements with high precision quickly. Aerial photos and satellite sensor images are used for generating 3D spatial images which are matched with the map coordinates and elevation data from digital topographic files. Also, those images are used for matching with 3D spatial image contents through perspective view condition composed along to the designated roads until arrival the corresponding location. Recently, 3D aviation image could be generated by various digital data. The advanced geographical methods for guidance of the destination road are experimented under the GIS environments. More information and access designated are guided by the multimedia contents on internet or from the public tour information desk using the simulation images. The height data based on LiDAR is transformed into DEM, and the real time unification of the vector via digital image mapping and raster via extract evaluation are transformed to trace the generated model of 3-dimensional downtown building along to the long distance for 3D tract model generation.