• Spatial Information Research
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• v.11 no.3
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• pp.203-212
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• 2003

An integrated 3D GIS-based approach for understanding underground environment is proposed and applied to a land subsidence in densely populated region. Bedrock and geological discontinues were treated as main factors in this study. Because land subsidence in this study area was caused by cavity owing to dissolved limestone in percolating ground water. Ground was classified according to bedrock types using a clustering method and geological information, N value, and RQD value of boreholes were visualized and integrated by 3D-GIS. Therefore it was possible to recognize underground space easily and analyze the ground information effectively.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.429-440
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• 2008

Formal Concept Analysis (FCA) is a widely used methodology for data analysis, which extracts concepts and builds a concept hierarchy from given data. A concept consists of objects and attributes shared by those objects, and a concept hierarchy includes information on super-sub relations among the concepts. In this paper, we propose a method for extracting Implication and Association rules from a concept hierarchy given a query by a user. The method also describes a way for displaying the extracted rules. Based on this method, we implemented an automatic tool, QAG-Wizard. Because the QAG-Wizard not only elicits relation information for the given query, but also displays it in structured form intuitively, we expect that it can be used in the fields of data analysis, data mining and information retrieval for various purposes.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.369-374
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• 2016

Recently, due to the rapid development of smart computing technology, there have been a lot of studies on 3D navigation, and consequently the advanced commercial 3D navigation system and 3D VTS system are on the market. Even the 3D technology is well known and wide spreaded, unfortunately, the secret of code behind is still unleashed. The purpose of this paper is to show the basic methodologies to display ENC features under 3D display environment to meet the requirement of S-52 standards. The OpenGL ES is used to develop 3D ENC Viewer for further use on mobile platforms and web based vessel monitoring system. P articularly, area object triangulation, complex line drawing, polygon pattern filling and symbol drawing by texture mapping are explained in detail. The result of performance test is shown as table for correlation of SENC file size to display speed.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.789-795
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• 2011

This paper aims to develop authoring tools and services platform that can be Immediate response through supervisor's intuitive understanding based 3d-Building Information mode about overall security situation of building by mapping many CCTV images on 3D space information from traditional observation way that make simply visualize CCTV images on the Situation Board.

• Journal of Biosystems Engineering
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• v.27 no.3
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• pp.227-234
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• 2002

This study was conducted to nondestructively estimate the volumetric information of peach and pit and to visualize the 3D information of internal structure from magnetic resonance imaging(MRI) data. Bruker Biospec 7T spectrometer operating at a proton reosonant frequency of 300 MHz was used for acquisition of MRI data of peach. Image processing algorithms and visualization techniques were implemented by using MATLAB (Mathworks) and Visualization Toolkit(Kitware), respectively. Thresholding algorithm and Kohonen's self organizing map(SOM) were applied to MRI data fur region segmentation. Volumetric information were estimated from segemented images and compared to the actual measurements. The average prediction errors of peach and pit volumes were 4.5%, 26.1%, respectively for the thresholding algorithm. and were 2.1%, 19.9%. respectively for the SOM. Although we couldn't get the statistically meaningful results with the limited number of samples, the average prediction errors were lower when the region segmentation was done by SOM rather than thresholding. The 3D visualization techniques such as isosurface construction and volume rendering were successfully implemented, by which we could nondestructively obtain the useful information of internal structures of peach.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.740-745
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• 2016

Cables are installed for tens of thousands of connections between various pieces of equipment to operate and control a commercial ship. The correct shortest-route data is necessary since these are complicated cable installations. Therefore, an overfill interval commonly exists in the shortest paths for cables as estimated by Dijkstra's algorithm, even if this algorithm is generally used. It is difficult for an electrical engineer to find the overfill interval in 3D cable models because the occupancy rate data exist in a data sheet unlinked to three-dimensional (3D) computer-aided design (CAD). The purpose of this study is to suggest a visualization method that displays the cable path and overfill interval in 3D CAD. This method also provides various color visualizations for different overfill ranges to easily determine the overfill interval. This method can reduce cable-installation man-hours from 7,000 to 5,600 thanks to a decreased re-installation rate, because the cable length calculation's accuracy is raised through fast and accurate reviews based on 3D cable visualization. As a result, material costs can also be reduced.

• Journal of the Korean GEO-environmental Society
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• v.19 no.5
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• pp.23-31
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• 2018

The dredging project became more important with the recent construction of off shore structures and reclamation projects. Accordingly, more exact quantitative estimation of the dredged amount should be required. The sub-sea ground information can be obtained generally by the boring investigation and the dredged amount can be estimated based on the depth or the deeper bound of a ceratin layer via 3D visualization program. During the estimation process, the input DB should be constructed with 1D elevation information from boring investigation for the spatially approximated distribution of a deeper bound of each ground layer. The input DB can be varied with the application of the borings and the approximation targets. Therefore, the 3D visualized ground profile and dredged amounts are compared on the actively dredged sites, vicinity of Saemangeum area and outer port area in Gunsan with regard to the input DB construction methods. Conclusively, the input DB based on the spatially approximated depths show higher precision results and more reasonable 3D visualized ground profiles.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.149-150
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• 2011

3차원 건설환경의 디지털기반의 가시화는 도시계획 및 통신계획, 건설, 건축, 입체적인 도시공간정보시스템 구현, 안전 및 방재 등에서 많은 필요와 그 중요성이 크게 부각되고 있다. 건설현장의 환경정보의 사전분석에 의하여 USN의 구성과 실시간 정보취득의 장점을 활용하여 기존의 항공사진과 DEM의 매칭에 의한 3D지형공간에 온도, 습도, 조도, 적외선량, GPS위치, 이산화탄소량 등의 환경정보를 실시간으로 원하는 장소와 시간에서 획득하여 이를 모바일 스마트폰으로 연결함으로서 새로운 건설환경정보를 사전에 분석할 수 있도록 하였다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.6
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• pp.94-103
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• 2001

The goal of using numerical methods in this study is two-fold: to replicate a set of measured, individualized HRTFs by a computer simulation, and also to visualise the resultant sound field around the head. Two methods can be wed: the Boundary Element Method (BEM) and the Infinite-Finite Element Method (IFEM). This paper presents the results of a preliminary study carried out on a KEMAR dummy-head, the geometry of which was captured with a high accuracy 3-D laser scanner and digitiser. The scanned computer model was converted to a few valid BEM and IFEM meshes with different polygon resolutions, enabling us to optimise the simulation for different frequency ranges. The results show a good agreement between simulations and measurements of the sound pressure at the blocked ear-canal of the dummy-head. The principle of reciprocity provides an effect method to simulate HRTF database. The BEM was also used to investigate the total sound field around the head, providing a tool to visualise the sound field for different arrangements of virtual acoustic imaging systems.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.1-14
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• 2006

Sort-last parallel rendering using a cluster of GPUs has been widely used as an efficient method for visualizing large- scale volume datasets. The performance of this method is constrained by load balancing when data parallelism is included. In previous works static partitioning could lead to self-balance when only task level parallelism is included. In this paper, we present a load balancing scheme that adapts to the characteristic of volume dataset when data parallelism is also employed. We effectively combine the hierarchical data structures (octree and BSP tree) in order to skip empty regions and distribute workload to corresponding rendering nodes. Moreover, we also exploit a 3D clustering method to determine visibility order and save the AGP bandwidths on each rendering node. Experimental results show that our scheme can achieve significant performance gains compared with traditional static load distribution schemes.