• Spatial Information Research
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• v.12 no.3
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• pp.275-283
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• 2004

In order to effectively, and accurately assess seawater intrusion in coastal area, multidisciplinary data including geophysical, well logging, and hydrogeochemical data should be managed in systematical way. Such systematical management of data is critical key to improve the re-usability of the data as well as the accuracy of the assessment by means of providing a method of synthetic analysis. Therefore, for systematical management of multidisciplinary data in seawater intrusion problem, we have developed a database management system and 3-D visualization interface based on geographic information system in this, study. All geophysical survey, well logging, hydrochemical, as well as drilling, data are classified as attribute data using Microsoft Access, and joined with spatial information based on ArcView. The database management system and 3-D visualization interface to handle these data, also, developed using the script language of ArcView. We think the development of database and 3-D visualization system will improve the efficiency of data management, user-friendliness of data access, and accuracy of data analysis.

• Journal of the Korean GEO-environmental Society
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• v.17 no.7
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• pp.35-42
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• 2016

There are many reclamation projects domestically and internationally which requires large quantity of reclaimable materials. To provide enough reclaimable soils which are limited in land, there have been various research focusing on the dredged soils in the marine environments. As a part of this research, a GIS based 3D dredging reclamation visualization program was developed for the volume estimation of dredged soils in 2015. The developed program is based on the digitized spatial information of the site investigation data with a consideration of the reliability of the data. Prior to the validation with the comparisons with the actual dredged volume measurement data, the developed program was compared with the commercial 3D visualization program with 3D visualized results from the test site near the Gunjang harbor. The validation of the developed program was performed in terms of the degree of visualized precision, the sectional and profiling of soil layers and the dredged volume estimation results. Based on the comparisons, both commercial and developed program show similar dredged volume with minor discrepancies in soil layers.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.4
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• pp.141-149
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• 2010

Three-dimensional geo-spatial information is important for the efficient use and management of the country and the three-dimensional expression and analysis of urban projects, such as urban plans devised by local governments and urban management. Thanks to the revitalization of the geo-spatial information service industry, it is now being variously used not only in public but also private areas. For the creation of high-guiltily three-dimensional geo-spatial information, emphasis should be placed on not only the quality of the source image and three-dimensional geo-spatial model but also the level of visualization, such as level of detail and texturing. However, in the case of existing three-dimensional geo-spatial information, its establishment process is complicated and its data are not updated frequently enough, as it uses ready-created digital maps. In addition, as it uses Ortho Images, the images exist Relief displacement. As a result, the visibility is low and the three-dimensional models of artificial features are simplified to reach LoD between 2 and 3, making the images look less realistic. Therefore, this paper, analyzed the quality of three-dimensional geo-spatial information created using the three-dimensional modeling technique were applied using Digital photogrammetry technique, using digital aerial photo images by an existing large-format digital camera and multi-looking camera. The analysis of the accuracy of visualization information of three-dimensional models showed that the source image alone, without other visualization information, secured the accuracy of 84% or more and that the establishment of three-dimensional spatial information carried out simultaneously with filming made it easier to gain the latest data. The analysis of the location accuracy of true Ortho images used in the work process showed that the location accuracy was better than the allowable horizontal position accuracy of 1:1,000 digital maps.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.7
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• pp.586-603
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• 2004

One of the subtle problems that make noise control difficult for engineers is “the invisibility of noise or sound.” The visual image of noise often helps to determine an appropriate means for noise control. There have been many attempts to fulfill this rather challenging objective. Theoretical or numerical means to visualize the sound field have been attempted and as a result, a great deal of progress has been accomplished, for example in the field of visualization of turbulent noise. However, most of the numerical methods are not quite ready to be applied practically to noise control issues. In the meantime, fast progress has made it possible instrumentally by using multiple microphones and fast signal processing systems, although these systems are not perfect but are useful. The state of the art system is recently available but still has many problematic issues : for example, how we can implement the visualized noise field. The constructed noise or sound picture always consists of bias and random errors, and consequently it is often difficult to determine the origin of the noise and the spatial shape of noise, as highlighted in the title. The first part of this paper introduces a brief history, which is associated with “sound visualization,” from Leonardo da Vinci's famous drawing on vortex street (Fig. 1) to modern acoustic holography and what has been accomplished by a line or surface array. The second part introduces the difficulties and the recent studies. These include de-Dopplerization and do-reverberation methods. The former is essential for visualizing a moving noise source, such as cars or trains. The latter relates to what produces noise in a room or closed space. Another mar issue associated this sound/noise visualization is whether or not Ivecan distinguish mutual dependence of noise in space : for example, we are asked to answer the question, “Can we see two birds singing or one bird with two beaks?"

• Spatial Information Research
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• v.22 no.4
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• pp.39-47
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• 2014

The Yeongsan river estuary has a serious water quality problem due to the water stagnation and it is imperative to predict the changes of water quality for mitigating water pollution. EFDC(Environmental Fluid Dynamics Code) model was mainly utilized to predict the changes of water quality for the estuary. The EFDC modeling normally accompanies the large volume of modeling output. For checking the spatial distribution of the modeling results, post-processing for converting of the output is prerequisite and mainly post-processing program is EFDC_Explorer. However, EFDC_Explorer only shows the spatial distribution of the time series and this doesn't support overlay function with other thematic maps. This means the impossible to the connection analysis with a various GIS data and high dimensional analysis. Therefore, this study aims to develop a post-processing system of a EFDC output to use them as GIS layers. For achieving this purpose, a editing module for main input files, and a module for converting binary format into an ASCII format, and a module for converting it into a layer format to use in a GIS based environment, and a module for visualizing the reconfigured model result efficiently were developed. Using the developed system, result file is possible to automatically convert the GIS based layer and it is possible to utilize for water quality management.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.63-72
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• 2010

In this study, an earth work design program which will improve the efficiency of earth work and enable to carry out the design using 3D Geospace-based earth work modelling in design stage was developed. Estimate of accurate earth work volume is achievable using 3D grid DEM, and based on this, a mass calculation chart was developed for movement of earth and equipment. In consideration for the resources for various construction equipments needed for civil engineering works, soil conversion and the passage is displayed. In addition, the result is restored in the form of open API-based KLM to make it possible for the users to identify the progress of the construction, thereby enhancing the intuitive understanding of three-dimensional visualization and making it easier to share the result of the analysis.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.581-588
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• 2002

In implementing interactive multimedia systems, real-time visualization plays an important role. This paper presents efficient data structures and algorithms for real-time terrain navigation. Terrain data set is usually too huge to display as is. Therefore LOD (levels of detail) methods and view frustum culling are essential tools. This paper describes in detail compact hierarchical data structures, fast view frustum culling, and efficient LOD construction/rendering algorithms. Unlike previous works, we use a precise screen-space error metric for vertex removal and a strict error threshold allowing sub-pixel -sized errors only. Nevertheless, we can achieve 22 fps on average in a PC platform. The methods presented in this paper also satisfy almost all of the requirements for interactive real-time terrain Visualization.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.416-416
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• 2012

최근 엄청난 폭우로 인해 발생한 하천의 범람으로 수많은 인명피해가 발생하였는데, 이를 위해 정부에서는 하천 정비를 포함한 치수 및 방재 정책을 꾸준히 펼치고 있다. 하지만, 지구온난화 등으로 인한 기후변화로 발생하는 자연재해는 예측치를 넘는 집중 호우로 인해 큰 효과를 보지 못하고 있는 실정이다. 이에 따라 홍수범람을 정확히 예측하기 위한 수치 모형에 대한 연구가 활발히 이루어져 왔으나 예측 모의결과가 수치적 자료 또는 도면으로 제시되어 재해관리자가 방대한 모의자료를 신속하게 검토하여 방재대책을 수립하는 데 어려움이 있다. 이와 같은 문제점을 개선하여 효과적으로 홍수 및 범람 예측결과를 제공하기 위해서는 모형결과를 가시화하기 위한 연구가 필요하며, 강우에 따른 2차원 수치해석을 이용하여 흐름의 변화 및 유량을 파악하고 2차적인 피해를 예방하고 원인을 규명하기 위해 최근 범람을 했던 지역의 자료를 이용하여 흐름의 특성을 파악함으로써 그러한 현상을 미연에 방지할 수 있다. 본 연구에서는 2011년 7월에 발생한 경기도 광주시 곤지암천 범람을 HEC-RAS 및 CCHE2D 모형을 이용하여 시간별로 제방 붕괴 시점 및 그에 따른 범람 해석을 모의하여 분석하였다. 이를 통해 당시 발생한 하천범람 현상을 예측하고 이를 예방하기 위한 대책을 제시하고자 한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.3
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• pp.273-282
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• 1999

For appling the GSIS on a air environment division, first of all, spatial-distribution of environmental factor which has distinction of continuous surface such as air-pollutant and a factor of weather must be able to be drawn. So we should estimate a distribution of whole area with point observation value which is observed on several restricted point. On this study, we investigate and study the application of GSIS technique which can be visible emission characteristic by regions, items, and time using data such as traffic quantity data, digital map for GIS-T and emission factor of each pollutant of vehicles about whole area of Seoul surveyed by traffic sensus of Seoul to air environment division.

• The Journal of Engineering Geology
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• v.25 no.3
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• pp.395-401
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• 2015

An investigation of the tunnel face, as well as related measurement data collected during tunneling, is necessary for rock classification and to determine tunnel stability and the cost efficiency of tunneling. However, systematic management and efficient use of such data have yet to be successfully implemented domestically, and the number of experts in this field in Korea is limited. Thus, measures to develop and implement systematic management and effective use of data and expertise are urgently needed. This study aimed to develop measures to efficiently provide online tunnel design and construction data using a building information model (BIM)-based data visualization approach, based on an integrated 3D tunnel model generation module and a web viewer module. The development technology was verified through ○○ tunnel design and construction. Directions for future study and system improvement are proposed.