• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.371-376
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• 2006

Digital high resolution cameras are widely available, and are increasingly use in digital close-range photogrammetry. And photogrammetry instruments are developing rapidly and the precision is improving continuously. The building of 3D terrains of high precision are possible and the calculation of the areas or the earthwork volumes have high precision due to the development of the technique of the spatial information system using computer. Using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D modeling of high-accuracy in pixel degree through digital close-range photogrammetry with bundle adjustment for digital elevation model generation.

• Korean Journal of Remote Sensing
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• v.29 no.3
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• pp.275-291
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• 2013

Monitoring the global Gross Primary Pproduction (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance ($R^2=0.8164$, $RMSE=0.6126g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$, $bias=-0.0271g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.461-468
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• 2008

The needs for visualizing interactive multimedia contents on portable devices with realistic three dimensional shapes are increasing as new ubiquitous services are coming into reality. Especially in digital fashion applications with virtual reality technologies for clothes of various forms on different avatars, it is required to provide very high quality visual models over mobile networks. Due to limited network bandwidths and memory spaces of portable devices, it is very difficult to transmit visual data effectively and render realistic appearance of three dimensional images. In this thesis, we propose a compression method to reduce three dimensional data for digital fashion applications. The three dimensional model includes animation of avatar which require very large amounts of data over time. Our proposed method utilizes temporal and spatial coherence of animation data, to reduce the amount. By grouping vertices from three dimensional models, the entire animation is represented by a movement path of a few representative vertices. The existing three dimensional model compression approaches can get benefits from the proposed method by reducing the compression sources through grouping. We expect that the proposed method to be applied not only to three dimensional garment animations but also to generic deformable objects.

• Molecules and Cells
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• v.38 no.11
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• pp.975-981
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• 2015

Precise 3D spatial mapping of cells and their connections within living tissues is required to fully understand developmental processes and neural activities. Zebrafish embryos are relatively small and optically transparent, making them the vertebrate model of choice for live in vivo imaging. However, embryonic brains cannot be imaged in their entirety by confocal or two-photon microscopy due to limitations in optical range and scanning speed. Here, we use light-sheet fluorescence microscopy to overcome these limitations and image the entire head of live transgenic zebrafish embryos. We simultaneously imaged cranial neurons and blood vessels during embryogenesis, generating comprehensive 3D maps that provide insight into the coordinated morphogenesis of the nervous system and vasculature during early development. In addition, blood cells circulating through the entire head, vagal and cardiac vasculature were also visualized at high resolution in a 3D movie. These data provide the foundation for the construction of a complete 4D atlas of zebrafish embryogenesis and neural activity.

• The Mathematical Education
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• v.48 no.1
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• pp.1-20
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• 2009

The study was to investigate an effect of students' learning for enhancing spatial ability, using a geometric manipulative recently designed. A mixed methodology was chosen to achieve the purpose of the study. To find students' achievement, 152 of the 8th graders in Kyunggi Do participated in data collection. At the same time. students' performance of the class was videotaped and analyzed to see students' responses, The results showed that the effect of using the manipulative was statistically significant at level, p<.05 to enhance the spatial ability. Specifically, in comparison of each component. spatial orientation was more effective than spatial visualization. In the spatial orientation, the part of field was more effective than the reorganized whole. It showed that students were given more opportunities to find mathematical properties and relations between 2nd and 3rd-dimensional figures through their intuitive observation, and also the manipulative helped the students find the property of the part of field because it gave an easy way to manipulate the property of the find parts of whole which was composed of the frame of the solid figures without surfaces. In using the manipulative, students were very flexible in finding the number of plane figures, but the relations between the 2nd and 3rd dimensional figures need to be clearly guided in consideration of the characteristics of the manipulative, based on the definitions of geometric properties(cf. points can make lines, not surfaces directly).

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.11-17
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• 2005

A lot of small-scale reservoirs that is extravagant in whole country are controlled state or real condition that correct data about the practice contents is not equipped all up to now. In this study, YungNam districts that region Gyeong-Ju city reservoir is distributed much of when flow speedily choose 23 peace among 73 small scale reservoir and experimented. Acquired data every 5 seconds, and user E/S and user value TS for orthocenter to 1 second interval and executes present condition measurement using RTK-GPS. Could was wave and state that reservoir of 15 places (about 65%) gives protective care that do 3D modelling with acquired data, and now correct contents about reservoir state past through comparative analysis with data. Also, area of full water and wave that analyze effective storage and area of full water of 23 places reservoir could know that 20.63%, effective storage decreased as 3.34%. I wish to contribute about analysis about present reservoir state through this and method the adminstration direction.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.431-439
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• 2000

In this study, a GIS-application model to determine the optimal route of eco-friendly forest roads and to evaluate the environmental and engineering features of the route was developed. The model consists of five modules for managing spatial and attribute data, determining the optimal route for forest road projection, evaluating environmental and engineering efficiency of forest roads, analyzing characteristics of mountain terrains and report-writing. Using the pull-down menu system, these modules were integrated to be user-friendly for forest field practitioners. Visual Basic 6.0 and Avenue were used as the programming tool and the commercial GIS softwares, ArcView 3.1, Spatial Analyst and 3-D Analyst were used as the basic engine of the model for GIS analysis. In this paper, discussed are the principles for forest road projection and evaluation and structures and application features of the model.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.99-105
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• 2013

In rapidly developing urban areas that include high-rise, large, and complex buildings, indoor and outdoor maps in GIS become a basis for utilizing and sharing information pertaining to various aspects of the real world. Although an indoor mapping has gained much attentions, research efforts are mostly in 2D and 3D modeling of terrain and buildings. Therefore, to facilitate fast and accurate construction of indoor GIS, this paper proposes a semi-automatic method consisting of preprocessing, 2D mapping, and 3D mapping stages. The preprocessing is designed to estimate heights of building interiors and to identify noise data from point clouds. In the 2D mapping, a floor map is extracted with a tracing grid and a refinement method. In the 3D mapping, a 3D wireframe model is created with heights from the preprocessing stage. 3D mesh data converted from noise data is combined with the 3D wireframe model for detail modeling. The proposed method was applied to point clouds depicting a hallway in a building. Experiment results indicate that the proposed method can be utilized to construct 2D and 3D maps for indoor GIS.

• Journal of Internet Computing and Services
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• v.23 no.1
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• pp.39-47
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• 2022

Digital Twin is positioned as one of the establishment of a digital management system for core infrastructure in terms of collecting real data and implementing virtual space. However, there are currently no integrated three-dimensional marine information analysis tools and technologies in Korea, and unlike land, new 3D modeling technologies and data processing technologies are required to digitize flexible marine information, but there are limitations in implementation. Therefore, this study aims to present development directions in four areas: structure, data, modeling, and utilization platform of marine digital twin by analyzing trends related to marine digital twin and digital twin technology elements.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.2
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• pp.152-161
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• 1993

This paper deals with the effect of spatial distribution of material properties on its statistical characteristics and numerical estimation method of reliability of fatigue sensitive structures with respect to the fatigue crack growth. A method is proposed to determine experimentally the probability distribution functions of material parameters of Paris law. da/dN=C(ΔK/K sub(0) ) super(m), using stress intensity factor controlled fatigue tests. The result with a high tensile strength steel shows that the distribution of the parameter m is approximately normal and that of 1/C, is a 3-parameter Weibull. The main result obtained are : (1) The theoretical autocorrelation of the resistance, 1/C, to fatigue crack growth are almost same for different lengths. (2) The variance decreases with the increasing a averaging length. When spatial correlation length is very small. the variane decreases significantly were the averaging length. (3) The probability distribution of load cycles or the number for a crack to reach a certain length can be estimated using these functions by simulation of non-Gaussian(expecially Weibull) Stochastic Process.