• Title/Summary/Keyword: data modelling

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Modelling Growth and Yield for Intensively Managed Forests

  • Burkhart, Harold E.
    • Journal of Forest and Environmental Science
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    • v.24 no.3
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    • pp.119-126
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    • 2008
  • Growth and yield prediction methods, ranging from whole-stand models to individual-tree models, have been developed for forest types managed for wood production. The resultant models are used for a host of purposes including inventory updating, management planning, evaluation of silvicultural alternatives, and harvest scheduling. Because of the large investment in developing growth and yield models for improved genotypes and silvicultural practices for loblolly pine (Pinus taeda) in the Southern United States, this region serves to illustrate approaches for modelling intensively managed forests. Analytical methods and computing power generally do not restrict development of reliable growth and yield models. However, long-term empirical observations on stand development, which are time consuming and expensive to obtain, often limit modelling efforts. Given that growth and yield models are used to project present volumes and to evaluate alternative treatment effects, data of both the inventory type and the experimental type are needed. Data for developing stand simulators for loblolly pine plantations have been obtained from a combination of permanent plots in operational forest stands and silvicultural experiments; these data collection efforts are described and summarized. Modelling is essential for integrating and synthesizing diverse information, identifying knowledge gaps, and making informed decisions. The questions being posed today are more complex than in the past, thus further accentuating the need for comprehensive models for stand development.

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Three-dimensional Crush Measurement Methodologies Using Two-dimensional Data (2차원 데이터를 활용한 3차원 충돌 변형 측정 방법)

  • Han, Inhwan;Kang, Heejin;Park, Jong-Chan;Ha, Yongmin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.3
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    • pp.254-262
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    • 2015
  • This paper presents 3D collision deformation modelling methodologies using photogrammetry for reconstruction of vehicle accidents. A vehicle's deformation shape in collision provides important information on how the vehicle collided. So effective measurement(scanning) and construction of a corresponding appropriate model are essential in the analysis of collision deformation shape for obtaining much information related to collision accident. Two measurement methods were used in this study: Indirect-photogrammetry which requires relatively small amount of photos or videos, and direct-photogrammetry which requires large amount of photos directly taken for the purpose of 3D modelling. When the indirect-photogrammetry method, which was mainly used in this study, lacked enough photographic information, already secured 2D numerical deformation data was used as a compensation. This made 3D collision deformation modelling for accident reconstruction analysis possible.

A Study on 3D MODELLING DATA BANK & 3D RENDERING Effect (3D MODELLING DATA BANK와 3D RENDERING 효과에 대한 연구 - 전통 문양의 현대적 재해석과 '함' 디자인 사례를 중심으로 -)

  • 이대우
    • Journal of the Korea Furniture Society
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    • v.10 no.2
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    • pp.79-86
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    • 1999
  • 본 연구는 국내가구 디자인 산업의 경쟁력 강화를 위한 사례의 하나로 디자인 작품을 시도하게 되었다. 지존의 디자인 모델링은 소프트 모델 또는 목업(mock up)개념에서 시행되어 디자이너가 직접 제작하기 전에는 3차원의 형상을 구현하기가 어려웠으며, 더욱이 문야의 적용은 실크스크린 또는 인쇄와 같은 처리기법으로 사용되었다. 이 방법은 시간, 경비, 공간, 자료의 보관 및 축적, 기타의 많은 문제점과 생산성 향상에 애로사항이 되어왔다. 요지와 같이 많은 문제점과 렌더링의 데이터베이스 뱅크는 활용 가능한 분야와 직종에 따라서 응용 가능하기 때문에 많은 실험적 시도가 요구된다. 디자인의 발상은 우리나라 전통문화의 가구디자인을 접목시킨 사례로서 시도하였으며, 형태와 문양을 현대적 개념에서 재해석하여 대입시켰다. 적용디자인 사례는 2개의 모델에 10가지의 패턴을 복합적으로 활용한 디자인 작품의 결과물이다. 이러한 결과는 다양한 디자인 연출과 시안을 추출할 수 있으며, 디자인 활동과 설계에 능률을 배가시키는 효과를 검증할 수 있겠다.

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A study on fatigue crack growth modelling by back propagation neural networks (역전파 신경회로망을 이용한 피로 균열성장 모델링에 관한 연구)

  • 주원식;조석수
    • Journal of Ocean Engineering and Technology
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    • v.10 no.1
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    • pp.65-74
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    • 1996
  • Up to now, the existing crack growth modelling has used a mathematical approximation but an assumed function have a great influence on this method. Especially, crack growth behavior that shows very strong nonlinearity needed complicated function which has difficulty in setting parameter of it. The main characteristics of neural network modelling to engineering field are simple calculations and absence of assumed function. In this paper, after discussing learning and generalization of neural networks, we performed crack growth modelling on the basis of above learning algorithms. J'-da/dt relation predicted by neural networks shows that test condition with unlearned data is simulated well within estimated mean error(5%).

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A Major DNA marker Mining of ILST035 microsatellite loci in Hanwoo Chromosome 6

  • Lee, Jea-Young;Yeo, Jung-Sou;Kim, Jae-Woo;Lee, Yong-Won
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.2
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    • pp.97-104
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    • 2002
  • K-Means modelling has been tried for finding major DNA marker of ILST035 microsatellite loci in Hanwoo Chromosome 6 linkage map. Major DNA markers are obtained from the ILST035 microsatellite through quantitative trait loci(QTL) and data mining modelling.

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Neural Network Modelling and Computer Simulation of the Local Circuits of the Outer Plexiform Layer in a Vertebrate Retina (망막 외망층의 국부회로에 대한 신경망 모델 및 컴퓨터 모의실험)

  • 이일병
    • Journal of Biomedical Engineering Research
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    • v.9 no.1
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    • pp.17-24
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    • 1988
  • This paper describes a neural network modelling of a vertebrate retina using a discrete-time and discrete-space approach based on neuro-anatomical data, and the computer simulations of the model which approximate the frog/amphibian negro-physiological data. It then compares them and describes how such a model can be beneficially used for confirming the hypothesis of a given neural system and further predict yet unknown experimental data.

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A Case Study on Blasting Vibration 3D Modelling with Electronic-Delay System Detonator (전자발파시스템을 이용한 발파진동 3D 모델링 연구 사례)

  • Kim, Gab-Su;Yang, Ruilin;Kim, Yong-Gyun;Kang, Dae-Woo
    • Tunnel and Underground Space
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    • v.24 no.2
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    • pp.131-142
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    • 2014
  • This study is using electronic-delay system detonator which can input an accurate detonating delay, compare predicted blasting vibration level derived from vibration 3D modelling with real measured blasting vibrations, and then considered modelling results are able to apply blast design. It confirmed there are certain relations between modelling and real vibration data, so modelling prediction method also can be apply design various blast conditions and prediction equation of blast vibration.

ON THE MODELLING OF TWO-PHASE FLOW IN HORIZONTAL LEGS OF A PWR

  • Bestion, D.;Serre, G.
    • Nuclear Engineering and Technology
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    • v.44 no.8
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    • pp.871-888
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    • 2012
  • This paper aims at presenting the state of the art, the recent progress, and the perspective for the future, in the modelling of two-phase flow in the horizontal legs of a PWR. All phenomena relevant for safety analysis are listed first. The selection of the modelling approach for system codes is then discussed, including the number of fluids or fields, the space and time resolution, and the use of flow regime maps. The classical two-fluid six-equation one-pressure model as it is implemented in the CATHARE code is then presented and its properties are described. It is shown that the axial effects of gravity forces may be correctly taken into account even in the case of change of the cross section area or of the pipe orientation. It is also shown that it can predict both fluvial and torrential flow with a possible hydraulic jump. Since phase stratification plays a dominant role, the Kelvin-Helmholtz instability and the stability of bubbly flow regime are discussed. A transition criterion based on a stability analysis of shallow water waves may be used to predict the Kelvin-Helmholtz instability. Recent experimental data obtained in the METERO test facility are analysed to model the transition from a bubbly to stratified flow regime. Finally, perspectives for further improvement of the modelling are drawn including dynamic modelling of turbulence and interfacial area and multi-field models.

Survey on the Application of three dimensional product modeling in the army (군에서의 3차원 제품 모델 적용 방안 연구)

  • Choi, Ki-In
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.12
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    • pp.5716-5720
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    • 2012
  • To expand the use of three dimensional(3D) product modelling in the army, we have analyzed military technical data management system, as well as the military guidelines for the unique format and content of technical data package. Because traditional munition sector is based on the machinery and equipment industry, they have usually applied two dimensional(2D) drawings to prepare a design and to make a product. For that reason, there is no provision for 3D product modelling as a technical data package in the military guideline. In this study, we proposed an improvement scheme for the vitalization of 3D product modelling in the army not only in terms of related guideline but also military technical data management system.

Efficient Triangulation Algorithm for Constructing the Model Surface from the Interpolation of Irregularly-Spaced Laser Scanned Data

  • Shon, Ho-Woong
    • Journal of the Korean Geophysical Society
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    • v.8 no.3
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    • pp.153-157
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    • 2005
  • A discussion of a method has been used with success in terrain modelling to estimate the height at any point on the land surface from irregularly distributed samples. The special requirements of terrain modelling are discussed as well as a detailed description of the algorithm and an example of its application.

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