• Title/Summary/Keyword: Level-of-detail

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A Hybrid Rendering Model to support LOD(Level of Detail) (LOD(Level of Detail)를 지원하는 하이브리드 렌더링 모델)

  • Kim, Hak-Ran;Park, Hwa-Jin
    • Journal of Digital Contents Society
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    • v.9 no.3
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    • pp.509-516
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    • 2008
  • We propose the Hybrid Rendering model to support multi-resolution for computer graphics. LOD method for computer graphics system considering performance of device environment and end-user preference usually adopts mesh resolution, mipmap in texture rendering, or oct-tree data structure in ray tracing. The hybrid rendering model, as a local shading model combining Gouraud shading model and a flat shading model, applies a proper shading method to each of polygons consisting of an object. This method can be an effective alternative to reduce real-time rendering time so that it can be utilized in real time adaptive service of computer graphic contents among various device environments under ubiquitous environments.

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A Study on the Level of Communication and Clinical Skills of Korean Medical Students by the Participatory Method of Role Playing (역할극의 참여방식에 따른 한의대생의 의사소통 및 진료기술 수준에 대한 연구)

  • Kim, Kyung-Soo;Jeong, Seo-Yun;Kim, Kyeong-Ok
    • Journal of Oriental Neuropsychiatry
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    • v.30 no.3
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    • pp.177-184
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    • 2019
  • Objectives: This purpose of this study was to examine the level of communication and clinical skills of Korean medical students according to the participatory method of role playing during medical education. Methods: A total of 100 fourth grade students from the Korean Medical College of Dongshin University in 2018 and 2019 were divided into two groups: Role players and scenario writers. After performing their role-playing, they were asked to complete questionnaires regarding two categories-communication and clinical skills-, consisting of 10 items. Results: 1. Communication skills were measured at approximately 80% of the expected level, and the level difference was shown in detail. 2. Clinical skills were measured at approximately 75% of the expected level, and the level difference was shown in detail. 3. The level of communication skills and the level of clinical skills according to the participatory method did not differ significantly. Conclusions: Writing scenarios in role playing can be observed as having the same effect on communication and clinical skill levels as acting.

A Study for the Optimal Expression Level Definition of BIM Model in Construction Phase (시공단계 BIM모델의 적정표현수준 정의를 위한 기초 연구)

  • Noh, Hae-ra;Kim, Ji-yun;Lee, Da-un;Yun, Seok-heon
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.4
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    • pp.378-388
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    • 2016
  • As the needs for the mega-sized, high-rise and irregular shape of building increase, domestic application of BIM in construction industry is increasing in recent years. In this circumstance, interests in BIM modeling and modeling detail level have been also increased. BIM that is based on a three-dimensions, requires a specific and precise building expressions. And model expression level required for each phase such as design, construction, and maintenance of the construction project could be different as its needs. Because that it is not clear to define the criteria for the expression level of construction BIM model, It is difficult to decide how detail and what to model is appropriate in the practical application of BIM model. It could be the reason why the productivity in construction project became lower and lower. In this study we consider the way how to improve the productivity of BIM and analyze the appropriate representation level of construction BIM model through the experts' survey. The results of study could suggest the basis for an appropriate expression level of construction BIM model.

A Study on Feature-Based Multi-Resolution Modelling - Part II: System Implementation and Criteria for Level of Detail (특징형상기반 다중해상도 모델링에 관한 연구 - Part II: 시스템 구현 및 상세수준 판단기준)

  • Lee K.Y.;Lee S.H.
    • Korean Journal of Computational Design and Engineering
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    • v.10 no.6
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    • pp.444-454
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    • 2005
  • Recently, the requirements of multi-resolution models of a solid model, which represent an object at multiple levels of feature detail, are increasing for engineering tasks such as analysis, network-based collaborative design, and virtual prototyping and manufacturing. The research on this area has focused on several topics: topological frameworks for representing multi-resolution solid models, criteria for the level of detail (LOD), and generation of valid models after rearrangement of features. As a solution to the feature rearrangement problem, the new concept of the effective zone of a feature is introduced in the former part of the paper. In this paper, we propose a feature-based non-manifold modeling system to provide multi-resolution models of a feature-based solid or non-manifold model on the basis of the effective feature zones. To facilitate the implementation, we introduce the class of the multi-resolution feature whose attributes contain all necessary information to build a multi-resolution solid model and extract LOD models from it. In addition, two methods are introduced to accelerate the extraction of LOD models from the multi-resolution modeling database: the one is using an NMT model, known as a merged set, to represent multi-resolution models, and the other is storing differences between adjacent LOD models to accelerate the transition to the other LOD. We also suggest the volume of the feature, regardless of feature type, as a criterion for the LOD. This criterion can be used in a wide range of applications, since there is no distinction between additive and subtractive features unlike the previous method.

Extraction of Runoff Component from Stage in Tidal River Using Wavelet Transform (Wavelet Transform을 이용한 감조하천 수위자료의 유출성분 추출)

  • Oh, Chang-Ryeol;Lee, Jin-Won;Jung, Sung-Won;Park, Sung-Chun
    • Journal of Korea Water Resources Association
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    • v.40 no.10
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    • pp.793-800
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    • 2007
  • This research applied to Wavelet transform that have soft resolution time and frequency area for stage of Hadong2 station in order to extract to discharge component by rainfall and tidal level component by tide. Approximation component(A6) of last level for wavelet decomposition displayed the biggest energy value 87.77%, and detail component(D3) energy value was 10.70% with periodicity of semidiurnal tide type(about 12 hours). Also skewness, kurtosis values of D3 have similar to tidal level of Yeosu. Approximation component(A6), Detail component(D6, D5) for Hadong2 stage was runoff component, and detail component(D4, D3, D2) was tide component according to effect of tide.

An Efficient Algorithm for Real-Time 3D Terrain Walkthrough

  • Hesse, Michael;Gavrilova, Marina L.
    • International Journal of CAD/CAM
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    • v.3 no.1_2
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    • pp.111-117
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    • 2003
  • The paper presents an efficient algorithm based on ROAM for visualization of large scale terrain models in real-time. The quality and smoothness of the terrain data visualization within a 3D interactive environment is preserved, while the complexity of the algorithm is kept on a reasonable level. The main contribution of the paper is an introduction of a number of efficient techniques such as implicit coordinates method within the patch array representing ROAM and the viewpoint dependent triangle rendering method for dynamic level of detail (LOD) updates. In addition, the paper presents experimental comparison of a variety of culling techniques, including a newly introduced method: relational position culling. These techniques are incorporated in the visualization software, which allows to achieve more realistic terrain representation and the real-time level of detail reduction.

Development of Realtime GRID Analysis Method based on the High Precision Streaming Data

  • Lee, HyeonSoo;Suh, YongCheol
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.6
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    • pp.569-578
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    • 2016
  • With the recent advancement of surveying and technology, the spatial data acquisition rates and precision have been improved continually. As the updates of spatial data are rapid, and the size of data increases in line with the advancing technology, the LOD (Level of Detail) algorithm has been adopted to process data expressions in real time in a streaming format with spatial data divided precisely into separate steps. The existing GRID analysis utilizes the single DEM, as it is, in examining and analyzing all data outside the analysis area as well, which results in extending the analysis time in proportion to the quantity of data. Hence, this study suggests a method to reduce analysis time and data throughput by acquiring and analyzing DEM data necessary for GRID analysis in real time based on the area of analysis and the level of precision, specifically for streaming DEM data, which is utilized mostly for 3D geographic information service.

A basic study 3D model advancement method for nuclear power plant (원자력 발전설비의 3D 모델 상세화 방안에 대한 기초 연구)

  • Lim, Byung-Ki
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.37-38
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    • 2018
  • BIM(Building Information Modeling) in the architecture, VDC(Virtual Design and Construction) defined CIFE(Center for Integrated Facility Engineering) of Stanford university in USA, and Data-driven design definition issued by TECDOC-1284 of IAEA are doing data-level design generated by 3D CAD technology, integrating and managing related information based on the 3D model, and Using 3D models effectively during nuclear power plant life cycle. 3D model of domestic nuclear power industry is using interference review between design fields, 4D system linked 3D construction model and schedule activity, but the 3D model generated in the design phase is effectively not utilized during the construction, operation, decommissioning. therefore, This study is aimed to suggest 3D model LOD(Level of Detail) advancement method through the analysis of existing literature, 2D drawings, and 3D models throughout nuclear power plant lifecycle.

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Prediction Based Dynamic Level of Detail in Flight Simulator (항공시뮬레이터에서 예측 기반의 동적 LOD 적용방안)

  • Kim, DongJin;Lim, Juho;Kim, Ki-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1363-1368
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    • 2016
  • Fast rendering speed is one of key functions to provide realistic scenes in flight simulator. However, since flight simulator mostly operates with high volume terrain data, rendering speed is reduced and changed very rapidly when it handles file containing too much vertexs. So, previous schemes make use of Level of Details (LOD) scheme to prevent this problem. But, since LOD is applied after the large number of vertexs are detected, transition between scenes is not completely smooth. To solve this problem, in this paper, we propose a new dynamic LOD scheme which controls LOD level in advance through prediction of vertex overload. To verify the proposed scheme, we implement the proposed scheme in our flight simulation through OpenSceneGraph(OSG) and identify the reduced number of vertexs and enhanced Frame Per Second (FPS) by comparing real data with predicted one.

A Study on Saliency-based Stroke LOD for Painterly Rendering (회화적 렌더링을 위한 세일리언시 기반의 스트로크 단계별 세부묘사 제어에 관한 연구)

  • Lee, Ho-Chang;Seo, Sang-Hyun;Yoon, Kyung-Hyun
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.3
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    • pp.199-209
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    • 2009
  • In this paper, we suggest a stroke level of detail (LOD) based on a saliency density. On painter]y rendering, the stroke LOD has an advantage of making the observer concentrate on the main object and improving accuracy of expression. For the stroke LOD, it is necessary to classify the detailed and abstracted area. We divide the area on the basis of saliency distribution and the level of detailed expression is controlled based on the saliency information. 'We define that the area of which the saliency distribution is high is a major subject that an artist tries to express, it is described in detail. The area of which the saliency distribution is low is abstractly described. Each divided area has the abstraction level. And by adapting the brushes of which sizes are appropriate to each level, it is possible to express the area which needs to be expressed in details from the one which needs to be expressed abstractly.