• Proceedings of the Korean Environmental Sciences Society Conference
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• 2016.10a
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• pp.240-240
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• 2016

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.673-689
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• 2022

To understand seasonal changes it is necessary to understand the relationship between celestial bodies in a three-dimensional space, and to this end, modeling activities in which students directly construct, use, evaluate, and modify three-dimensional models are important. In this study, the process of elementary school students using globes and light bulbs to model Earth's motion in a three-dimensional space as a cause of seasonal changes was analyzed. Seventeen sixth graders participated in the modeling process. After exploring phenomena and concepts related to seasonal change, students constructed models using globes and bulbs and used them to explain seasonal changes. Video data recording students' modeling process, students' activity sheets, and transcripts of post-interview were used as research data, and data triangulation was conducted. The modeling level analysis framework was also developed based on previous studies. In particular, the framework was developed in detail in this study in consideration of the concept of Earth's motion as well as understanding model and implementing modeling. In the final analysis framework, the 3D modeling level was classified from level 1 to level 3, and student performance that may appear at each level was specified. As a result of the study, there were two main levels of modeling using globes for elementary school students to explain seasonal changes. The rotation and tilt of the axis of rotation and revolution of the earth were considered but the level at which empirical evidence was not used (level 2), the level at which empirical evidence was used to explain seasonal chages (level 3). However, even when students use empirical evidence, it did not lead to the construction of a scientific model. In this study, the cause was explored in relation to the characteristics of the tool used for modeling.

• Journal of Korean Association for Spatial Structures
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• v.8 no.3
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• pp.83-90
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• 2008

It is hard to predict the mechanical characteristics of discontinuous stone masonry structures by the static analysis method, because of irregularity of face stones and also due to randomness of backfill materials. Inversely, one can estimate the mechanical characteristics by comparing the natural frequencies between measured and computed. The aim of this paper is to investigate the computational modeling method of ancient stone arch bridges in Korea and to find the factors influencing their dynamic characteristics. The results revealed that the rigidity of spandrel walls and backfill materials are the most important factors influencing the natural frequencies of stone arch bridges.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.564-569
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• 2001

본 논문은 기존의 3D게임엔진에 실시간으로 상호작용이 가능하고 3D MMORPG(Massive Multi-play Outline Role Playing Game) 게임에 적합한 가상공간을 표현하기 위한 필요한 기술을 분석하고 이를 활용하려 한다. 기존의 머드 게임에 3차원 기술적용하고, 3차원 물체를 모델링하는데 있어서 메쉬나 버텍스, 혹은 폴리곤으로 사실적인 지형처리와 렌드링 속도향상을 위하여 3차원 개체의 폴리곤을 동적으로 생성시키기 위한 방법으로 Height field처리 기법과 거리에 따라 다르게 모델링된 데이터를 선택적으로 사용하는 LOD(Level of Detail)처리기법과 가시성 판단이나 충돌 검출을 위한 입체 컬링 방법으로 옥트리를 이용하여 가상공간을 분해 하기 위한 자료 구조로 사용한다. 본 논문은 기존의 3차원 공간을 표현하기 위하여 사용되고 있는 옥트리 구조를 이용하여 공간을 분할하고, 이를 세부수준으로 나누어 처리하기 위한 LOD 개념을 이용하여 외부지형을 폴리곤으로 표현하는 방법에 대한 처리 기법을 제시하려고 한다.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.33-42
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• 2021

As smartphone-based tourism platforms have become active, policy establishment and service enhancement using review data are being made in various fields. In the case of the preceding studies using tourism review data, most of the studies centered on domestic tourists were conducted, and in the case of foreign tourist studies, studies were conducted only on data collected in some languages and text mining techniques. In this study, 3,515 review data written by foreigners were collected by designating the "Daegu attractions" keyword through the online review site. And LDA-based topic modeling was performed to derive tourism topics. The spatial approach through global and local spatial autocorrelation analysis for each topic can be said to be different from previous studies. As a result of the analysis, it was confirmed that there is a global spatial autocorrelation, and that tourist destinations mainly visited by foreigners are concentrated locally. In addition, hot spots have been drawn around Jung-gu in most of the topics. Based on the analysis results, it is expected to be used as a basic research for spatial analysis based on local government foreign tourism policy establishment and topic modeling. And The limitations of this study were also presented.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.415-422
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• 2013

The contents development for the Internet and cyber tour has been attempted in a number of areas. 3D topography of the spatial environment, land planning and land information contents as a 3D tour of the future ubiquitous city safe for tourism due to the implementation of information made available major area. Domestic service, and in urban areas of the country where land and precise spatial information in order to shoot satellites and aircraft in the area you want to mount the camera on a variety of photo images taken by conducting 3D spatial that is required is able to obtain the information. Geo spatial information in a variety of direct or indirect acquisition of the initial spatial data into a database for accurate collection, storage, editing, manipulation and application technology changes in the future by establishing a database of 3D spatial by securing content organization ubiquitous tourist to take advantage of new tourism industry was greatly. As a result of this study for future tourism using geo spatial information and analysis of 3D modeling by intelligent land information indirectly, with quite a few stereo site experience and a variety of tourist spatial acquisition and utilization of information could prove.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.10
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• pp.833-839
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• 2012

In this paper, we analyze the reconstruction error in the modeling of flow field on BFS(Backward Facing Step). In order for the mathematical modelling of a density on the field, the spatial and temporal modes are extracted by POD(Proper Orthogonal Decomposition) method. After formulating the modeling error, we summarize the relationship between the energy strength and the reconstruction errors. Moreover the allowable modeling error limits in the flow control point of view are confined by analysing in the frequency domain as well as time domain of the reconstructed data.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.419-425
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• 2005

산악지역을 관통하는 도로의 경우 그 특성상 절토 후 도로를 시공하는 경우가 자주 있으며 때로는 매우 긴 구간에 일조가 적게 나타나 음영이 오래 지속되는 곳이 발생한다. 본 연구는 GIS를 이용하여 도로의 노선계획시 예상되는 일조영향을 평가하여 정확한 데이터를 제공하고자 한다. 실험대상지역을 선정하고 수치지형자료의 변환을 통하여 3D 지형 메쉬데이터를 작성하고 동일좌표체계의 도로선형자료를 반영하여 정확한 도로모델링을 생성하므로써 도로의 각 지점별 일조영향분석을 위한 기초자료를 구축하였다. 또한 도로노면상의 음영시간을 계산하고 일영이 도로 전체에 어느 정도 유지되는지를 가시적으로 모델링화하여 계절별 시간대별로 도식화하므로써 판단자의 시각적 분석을 가능케 하였다.

• Geophysics and Geophysical Exploration
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• v.5 no.2
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• pp.71-77
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• 2002

We developed a modeling and visualization software that can analyze 3-dimensional seismic data. The software divides 3 dimensional space into a series of vertical and horizontal polygons, and allows the various seismic attributes and other spatial information to be stored on these polygons. The program can pick a particular pattern in semi-automatic mode, and store the pattern in the spatial DB. The pattern can be modeled and visualized in 3 dimensional space.

• Spatial Information Research
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• v.17 no.1
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• pp.25-37
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• 2009

In this paper, we propose techniques for hazard analysis of curved road based on USN. The techniques consist of models and algorithms. Models of curved road, road direction, sensor, vehicle and hazard are proposed. To analyze hazard in curved road and give warning to corresponding vehicle in realtime multi-level algorithms are proposed. An application program implements the models and algorithms to simulate proposed techniques with real-time visualization.