• Title/Summary/Keyword: modelling methods

Search Result 528, Processing Time 0.028 seconds

Modelling on Multi-modal Circular Data using von Mises Mixture Distribution

  • Jang, Young-Mi;Yang, Dong-Yoon;Lee, Jin-Young;Na, Jong-Hwa
    • Communications for Statistical Applications and Methods
    • /
    • v.14 no.3
    • /
    • pp.517-530
    • /
    • 2007
  • We studied a modelling process for unimodal and multimodal circular data by using von Mises and its mixture distribution. In particular we suggested EM algorithm to find ML estimates of the mixture model. Simulation results showed the suggested methods are very accurate. Applications to two kinds of real data sets are also included.

A Study on the Generation and Application of Photometric Data for Lighting Simulation (조명 시뮬레이션을 위한 측광데이터의 생성과 적용)

  • Hong, Sung-De
    • Journal of The Korean Digital Architecture Interior Association
    • /
    • v.6 no.2
    • /
    • pp.25-30
    • /
    • 2006
  • The purpose of this study was to investigate how student felt the strengths and shortness of presentation methods for formation of interior spaces. For this study, the process of the interior architecture design class was divided into three stages: the programming. the design development, and the design completion. In the design development stage, students used presentation methods: hand sketch, scale model, computer modeling, and virtual realty. The strengths of hand sketch was that quick expression. Models provided three-dimensional feelings. Computer modelling provide realistic color and texture. Virtual reality provided three-dimensional immersion and real scale. It is effective that students collect brain storm images using quick hand sketch in the beginning of design development stage. After that, they compose interior spaces in study models with small scale. Watching the models, they design details of spaces by using hand sketch and computer modelling. Using virtual reality, they can check the scale and circulation. Finally, they complete computer modelling by texture mapping and check the final design in virtual reality.

  • PDF

Micro modelling of masonry walls by plane bar elements for detecting elastic behavior

  • Doven, Mahmud Sami;Kafkas, Ugur
    • Structural Engineering and Mechanics
    • /
    • v.62 no.5
    • /
    • pp.643-649
    • /
    • 2017
  • Masonry walls are amongst the oldest building systems. A large portion of the research on these structures focuses on the load-bearing walls. Numerical methods have been generally used in modelling load-bearing walls during recent years. In this context, macro and micro modelling techniques emerge as widely accepted techniques. Micro modelling is used to investigate the local behaviour of load-bearing walls in detail whereas macro modelling is used to investigate the general behaviour of masonry buildings. The main objective of this study is to investigate the elastic behaviour of the load- bearing walls in masonry buildings by using micro modelling technique. In order to do this the brick and mortar units of the masonry walls are modelled by the combination of plane truss elements and plane frame elements with no shear deformations. The model used in this study has fewer unknowns then the models encountered in the references. In this study the vertical frame elements have equivalent elasticity modulus and moment of inertia which are calculated by the developed software. Under in-plane static loads the elastic displacements of the masonry walls, which are encountered in literature, are calculated by the developed software, where brick units are modelled by plane frame elements, horizontal joints are modelled by vertical frame elements and vertical joints are modelled by horizontal plane truss elements. The calculated results are compatible with those given in the references.

Security Analysis based on Differential Entropy m 3D Model Hashing (3D 모델 해싱의 미분 엔트로피 기반 보안성 분석)

  • Lee, Suk-Hwan;Kwon, Ki-Ryong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.12C
    • /
    • pp.995-1003
    • /
    • 2010
  • The content-based hashing for authentication and copy protection of image, video and 3D model has to satisfy the robustness and the security. For the security analysis of the hash value, the modelling method based on differential entropy had been presented. But this modelling can be only applied to the image hashing. This paper presents the modelling for the security analysis of the hash feature value in 3D model hashing based on differential entropy. The proposed security analysis modeling design the feature extracting methods of two types and then analyze the security of two feature values by using differential entropy modelling. In our experiment, we evaluated the security of feature extracting methods of two types and discussed about the trade-off relation of the security and the robustness of hash value.

Model Checking for Joint Modelling of Mean and Dispersion (평균과 산포의 동시 모형화에 대한 모형검토)

  • Ha, Il-Do;Lee, Woo-Dong;Cho, Geon-Ho
    • Journal of the Korean Data and Information Science Society
    • /
    • v.8 no.2
    • /
    • pp.195-209
    • /
    • 1997
  • The joint modelling of mean and dispersion in quasi-likelihood models which greatly extend the scope of generalized linear models, is required in case that the dispersion parameter, the variance component of response variables, is not constant but changes by depending on any covariates. In this paper, by using statistical package GENSTAT(release 5.3.2, 1996) which makes a easily analyze real data through this joint modelling, we mention necessities that must consider this joint modelling rather than existing mean models through model checking based on graphic methods for esterase assay data introduced by Carrol and Ruppert(1987, pp.46-47), and then study methods finding reasonable joint model of mean and dispersion for this data.

  • PDF

Modelling Growth and Yield for Intensively Managed Forests

  • Burkhart, Harold E.
    • Journal of Forest and Environmental Science
    • /
    • v.24 no.3
    • /
    • pp.119-126
    • /
    • 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.

  • PDF

Semi-Rigid connections in steel structures: State-of-the-Art report on modelling, analysis and design

  • Celik, Huseyin Kursat;Sakar, Gokhan
    • Steel and Composite Structures
    • /
    • v.45 no.1
    • /
    • pp.1-21
    • /
    • 2022
  • In the structural analysis of steel frames, joints are generally considered as rigid or hinged considering their moment transfer ability. However, the first studies conducted with the beginning of the 20th century showed that the joints do not actually fit these two definitions. In reality, a joint behaves between these two extreme points and is called semi-rigid. Including the actual state of the joint in the structural analysis provides significant economic advantages, so the subject is an intense field of study today. However, it does not find enough application area in practice. For this reason, a large-scale literature published from the first studies on the subject to the present has been examined within the scope of the study. Three important points have been identified in order to examine a joint realistically; modelling the load-displacement relationship, performing the structural analysis and how to design. Joint modelling methods were grouped under 7 main headings as analytical, empirical, mechanical, numerical, informational, hybrid and experimental. In addition to the moment-rotation, other important external load effects like axial force, shear and torsion were considered. Various evaluations were made to expand the practical application area of semi-rigid connections by examining analysis methods and design approaches. Dynamic behaviour was also included in the study, and besides column-beam connections, other important connection types such as beam-beam, column-beam-cross, base connection were also examined in this paper.

FUSION OF LASER SCANNING DATA, DIGITAL MAPS, AERIAL PHOTOGRAPHS AND SATELLITE IMAGES FOR BUILDING MODELLING

  • Han, Seung-Hee;Bae, Yeon-Soung;Kim, Hong-Jin;Bae, Sang-Ho
    • Proceedings of the KSRS Conference
    • /
    • v.2
    • /
    • pp.899-902
    • /
    • 2006
  • For a quick and accurate 3D modelling of a building, laser scanning data, digital maps, aerial photographs and satellite images should be fusioned. Moreover, library establishment according to a standard structure of a building and effective texturing method are required in order to determine the structure of a building. In this study, we made a standard library by categorizing Korean village forms and presented a model that can predict a structure of a building from a shape of the roof on an aerial photo image. We made an ortho image using the high-definition digital image and considerable amount of ground scanning point cloud and mapped this image. These methods enabled a more quick and accurate building modelling.

  • PDF

Extended Trigger Modelling for the Workflow Analysis and Design: Case of Telecommunication Company (워크플로 분석/설계를 위한 확장 트리거 모델링: 전화국 사례)

  • Han, Dong-Il;Park, Sei-Kwon
    • IE interfaces
    • /
    • v.9 no.3
    • /
    • pp.236-248
    • /
    • 1996
  • Most of business enterprises today struggle with the coordination of work which is one of the most challenging problems in the business environment. And the situation becomes worse by the increasing complexity and uncertainty. In this paper, suitability of workflow technology for the modelling, optimization, and automation in the complex business structures is discussed. Also, in the abscence of a fully fledged method for analysis and design of workflow systems, this paper proposes a method, ETM(Extended Trigger Modelling), which can solve several problems in other methods. The proposed ETM approach consists of three stages such as situation analysis stage, activity coordination stage and implementation preparation stage. A modelling case of the proposed procedure is also presented.

  • PDF