• Journal of Korea Game Society
• /
• v.11 no.1
• /
• pp.131-138
• /
• 2011

Recently in terrain rendeing, most researches introduce mipmap-based out-of-core methods for handling large sized DEM data which does not fit in main memory of general computer. However, mipmap-based LOD(level-of-detail) methods occur geometric errors which appear in data simplifying the higher LOD level. These geometric errors cause geometric popping effects where LOD level changes when viewpoint moves. In this paper, we propose vertex cohesion map for reducing geometric error. In preprocessing step, we generate vertex cohesion map, which is a texture that stores the vectors. By these vectors, each vertex will be cohered into the position in which the difference of gradient value is bigger than others. Therefore in terrain rendering, using vertex cohesion map can dramatically reduce the geometry popping effects rather than using mipmap.

• Spatial Information Research
• /
• v.14 no.3 s.38
• /
• pp.321-334
• /
• 2006

3D spatial data are of increasing interest in landscape analysis, urban planning and map services based on Web, because of its reality. But the amount of 3D spatial data are very large in comparison with 2D spatial data. Therefore it is necessary to have a efficient methods to transfer and visualize 3D spatial data. The concept of Level of Detail in Computer Graphics is effective. This paper briefly presents two LOD data models of data transmission based on the spatial data model of international standards. First, it is separated LOD model that gives a LOD level to object. Second is Selective LOD model that gives a LOD level to object's element. We compared the efficiency of 3D data transmission based on two LOD model.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.5
• /
• pp.537-544
• /
• 2019

In currently electronic systems, the speed of information integration has increased due to the development of electronic technology. However, due to the increase in the number of parts and groups, the product structure has become complicated. In this paper, a study was conducted to evaluate quantitatively the replacement of a small equipment. First, the level of the replacement was determined through the algorithm for the replacement level of parts. Next, we defined the ease of detail replacment, and the factors for each detail replacement. In order to calculate the weighting of the detail ease, we performed the analysis of the replacement process of subcomponents of communication exchanger and defined the evaluation criteria. Finally, the completion of the evaluation check sheet and the evaluation score table.

• Journal of the Ergonomics Society of Korea
• /
• v.28 no.4
• /
• pp.71-76
• /
• 2009

Effects of dark adaptation have large safety implications. This study was aimed to investigate the effects of varying illuminance and the size of critical detail on visual performance (i.e., time-to-detect) in a dark room environment. While adapting to the dark environment, ten subjects were asked to detect and answer simple numerical expressions under 9 experimental conditions (3 illuminance level $\times$ 3 target size). The ANOVA results revealed that the time-to-detect was significantly affected by both of the illumination level and the size of critical detail. As illumination increased from 10 lux to 20 lux, the time-to-detect was significantly declined. For the size of critical detail, 0.5/min size (i.e., equal to 2 minutes of visual angle) resulted in a shorter time-to-detect, as compared to 0.7/min size (i.e., equal to 1.6 minutes of visual angle). Potential applications of this research include the development of design guidelines for illumination and warning signs in poorly illuminated viewing environments.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2002.11a
• /
• pp.163-170
• /
• 2002

Terrain surfaces have to be modeled in very detail and wheel-surface contacting geometry must be well defined in order to obtain proper ground-reaction and friction forces for realistic simulation of off-road vehicles. Delaunay triangulation is one of the most widely used methods in modeling 3-dimensional terrain surfaces, and T-search is a relevant algorithm for searching resulting triangular polygons. The T-search method searches polygons in successive order and may not allow real-time computation of off-road vehicle dynamics if the terrain is modeled with many polygons, depending on the computer performance used in the simulation. In order to accelerate the searching speed of T-search, a terrain database of triangular polygons is modeled in multi-levels by adopting the LOD (Level of Detail) method used in realtime computer graphics. Simulation results show that the new LOD search is effective in shortening the required computing time. The LOD search can be even further accelerated by introducing an NN (Neural Network) algorithm, in the cases where a appropriate range of moving paths can be predicted by cultual information of the simulated terrain, such as lakes, houses, etc.. Numerical tests show that LOD-NN search almost double the speed of the original T-search.

• Journal of KIBIM
• /
• v.3 no.1
• /
• pp.1-10
• /
• 2013

BIM(Building Information Modeling) ordering manuals and guidelines are diffused with the recent BIM activation. However, it is causing drawbacks such as an increase of work at each design stage and a decline of BIM application level that the standard of making up and managing BIM is vague and it includes comprehensive meaning. Therefore, this study aims to secure BIM work standard by establishing BIM making-out standard based on LOD(Level of Detail) classification considering domestic design process. It compared each definition of LOD by analyzing domestic and foreign BIM guideline examples, and figured out insufficiency of existing domestic and foreign design process and BIM guidelines. Moreover, it drew architects' work articles for promoting the progression of the efficient design process, and analyzed BIM requirements on design process, dividing BIM application scale by field. Through this analyzing process, it finally established BIM making-out standard classified by design process. The effects of establishing BIM making-out standard would include improving a division of labor and cooperation environment by creating integrated BIM model on design stages, advancing work efficiency by preventing a repetition and an increase of work, and upgrading project completeness and design quality. Besides, it can secure BIM work standard by clarifying responsibility for working steps. BIM making-out standard established by this study will contribute to developing the future BIM work standard document and BIM guideline as a data base.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.21 no.3
• /
• pp.205-213
• /
• 2018

Hyperspectral image is more increasing spectral resolution that Multi-spectral image. Because of that, each pixel of the hyperspectral image includes much more information and it is considered the most appropriate technic for land cover classification. but recent research of hyperspectral image is stayed land cover classification of general level. therefore we classified land cover of detail level using ED, SAM, SSS method and made Decision Tree from result of that. As a result, the overall accuracy of general level was improved by 1.68% and the overall accuracy of detail level was improved by 5.56%.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.35-38
• /
• 2004

We developed a Near Real-Time Validation System (NRVS) for the Level-2 Products of AQUA Satellite. AQUA satellite is the second largest project of Earth Observing System (EOS) mission of NASA. This satellite provides the information of water cycle of the entire earth with many different forms. Among its products, we have used five kinds of level-2 geophysical parameters containing rain rate, sea surface wind speed, skin surface temperature, atmospheric temperature profile, and atmospheric humidity profile. To use these products in a scientific purpose, reasonable quantification is indispensable. In this paper we explain the near real-time validation system process and its detail algorithm. Its simulation results are also analyzed in a quantitative way. As reference data set in-situ measured meteorological data which are periodically gathered and provided by the Korea Meteorological Administration (KMA) is processed. Not only site-specific analysis but also time-series analysis of the validation results are explained and detail algorithms are described.

• International conference on construction engineering and project management
• /
• 2013.01a
• /
• pp.419-425
• /
• 2013

Recently AEC industry has required construction automation according to becoming large and complex. Thus BIM-based construction project is increased and used in whole fields of AEC industry. Quantity take-off and estimation fields are important factor for decision-making in conceptual and schematic design stages of construction projects. The purpose of this study improves reliability of the estimation through QTO based on Open BIM. Scope and method to apply QTO is to select conceptual design stage through LoD(Level of Detail) in AEC field and to extract information from BIM model through analysis of IFC structure. This study proceeds three step to make BIM model and check the model quality and calculate QTO. The methodology of QTO using IFC is to verify of result in this study and expects utilizing in design stage of construction projects. The result from this study is expected to decrease the risk factor and time of estimation in the project early phase through improving reliability of schematic estimation.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.22 no.53
• /
• pp.89-97
• /
• 1999

We are concerned with the optimal design of flexible manufacturing cells in this study, thus try to suggest the detail information for each resource on the optimal conditions. Object oriented simulation technology is used to write models more easily and to execute simulation running time more rapidly, and the optimal level of relevant decision variables is probed by response surface methodology(RSM), which is well known for the optimization technology based on experiment design and regression equation. We investigate the optimal level for the number of pallets and the speed of AGVs of FMC systems, carry out the performance analysis of this system. Consequently we suggest systematic procedures for the optimization of FMCs in detail design stage.