• Title/Summary/Keyword: Geometry Transformation

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Transforming Objects and a Scene Tree of MPEG-4 Contents for Mobile Devices (모바일 장치를 위한 MPEG-4 콘텐츠의 객체 및 장면 트리 변환)

  • Kim Sangwook;Kim Kyungdeok;Lee Sookyoung
    • Journal of KIISE:Computing Practices and Letters
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    • v.11 no.2
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    • pp.124-132
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    • 2005
  • We propose a method using a transformation of an object and a scene tree in order to author MPEG-4 contents for mobile devices in this paper. The method transforms media objects in the scene into geometry objects in order to reduce initial loading time of the contents, and reduces an external form of each object in a scene of the content for presenting it efficiently on the small interface of mobile devices. Therefore, the contents for mobile devices are reconstructed by the method. An original object in the scene is presented on a mobile device when a user clicks a related geometry object. The method was applied to a conventional authoring tool, so we could find that the method showed an efficient presentation of MPEG-4 contents on mobile devices.

Automatic Process Planning Design and Finite Element Method for The Multistage Cold Forged Parts (다단 냉간단조품의 자동공정설계시스템과 유한요소법)

  • 최재찬;김병민;이언호;김동진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.200-205
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    • 1993
  • The automatic forming sequence design system can determine desirable operation sequences even if they have little experience in the design of cold forging process. This system is proposed,which generates forming sequence plans for the multistage cold forging of zxisymmetrical solid products. Since the process of metal forming can be considered as a transformation of geometry, treatment of the geometry of the product is a key in planning processes. Forming sequence for the part can be determined by means of primitive geometries such as cylinder,cone, convex, and concave. By utilizing this geometrical characteristics(diameter,height, and radius),the product geometry is expressed by a list of the pnmitive geometries. Accordingly, the forming sequence design is formulated as the search problem which starts with a billet geometry and finishes with a given product one. Using the developed system, the sequence drawing with all dimensions, which includes the proper sequence of operations for the part, is generated under the environment of AutoCAD. The preliminary choice of some feasible forming sequences can verify by using the finite element simulation.

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The Historical Background of Erlangen Program (에를랑겐 프로그램의 성립 배경)

  • Han, Kyeong Hye
    • Journal for History of Mathematics
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    • v.26 no.4
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    • pp.233-243
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    • 2013
  • The Erlangen program is a scholastic plan by German mathematician Felix Klein, in which he, based on group theory, made a reassessment of geometry as well as an attempt to generally organize it. In this paper, I will introduce the historical and scholastic background of the Erlangen program, overview the process of its formation, and provide some comments regarding its historical significance.

Influence of geometry and loading conditions on the dynamics of martensitic fronts

  • Berezovski, Arkadi
    • Smart Structures and Systems
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    • v.4 no.2
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    • pp.123-135
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    • 2008
  • Damping capacity of SMA damping devices is simulated numerically under distinct geometry and loading conditions. Two-dimensional numerical simulations are performed on the basis of a phenomenological model of dynamics of martensite-austenite phase boundaries. Results of the simulations predict the time delay and the value of the stress transferred to other parts of a construction by a damper device.

TOPOLOGICAL METHOD DOES NOT WORK FOR FRANKEL-MCDUFF CONJECTURE

  • Kim, Min Kyu
    • Journal of the Chungcheong Mathematical Society
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    • v.20 no.1
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    • pp.31-35
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    • 2007
  • In dealing with transformation group, topological approach is very natural. But, it is not sufficient to investigate geometric properties of transformation group and we need geometric method. Frankel-McDuff Conjecture is very interesting in the point that it shows struggling between topological method and geometric method. In this paper, the author suggest generalized Frankel-McDuff conjecture as a topological version of the conjecture and construct a counterexample for the generalized version, and from this we assert that topological method does not work for Frankel-McDuff Conjecture.

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Binary classification on compositional data

  • Joo, Jae Yun;Lee, Seokho
    • Communications for Statistical Applications and Methods
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    • v.28 no.1
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    • pp.89-97
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    • 2021
  • Due to boundedness and sum constraint, compositional data are often transformed by logratio transformation and their transformed data are put into traditional binary classification or discriminant analysis. However, it may be problematic to directly apply traditional multivariate approaches to the transformed data because class distributions are not Gaussian and Bayes decision boundary are not polynomial on the transformed space. In this study, we propose to use flexible classification approaches to transformed data for compositional data classification. Empirical studies using synthetic and real examples demonstrate that flexible approaches outperform traditional multivariate classification or discriminant analysis.

GEOMETRY OF SATELLITE IMAGES - CALIBRATION AND MATHEMATICAL MODELS

  • JACOBSEN KARSTEN
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.182-185
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    • 2005
  • Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

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Image Transformation Logics for Caricature Generation : The Focus on Emotional Form (캐리커처 자동 생성을 위한 이미지 변형 법칙에 관한 연구 - 감성적 형태 중심의 변형 방법 -)

  • Kim, Sung-Kon
    • Science of Emotion and Sensibility
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    • v.12 no.1
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    • pp.129-136
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    • 2009
  • Unlike former researches, this study for developing the caricature generator began observing the methods that other caricature experts have adopted. According to the observation, it seemed that experts tried to exaggerate characteristics of the target shape from other similar objects. When we are saying "This is similar to that," we give salience to their difference among the identical form groups. This study was to find the most similar geometry form to the target shape and then to transform its form through exaggeration. The research scope was restricted to exaggerate the outline shape of two-dimensional looped curve as a caricature form. For this, the author discussed the following: (a) organization method of four kinds of similar geometry form database, (b) search method to find the pertinent similar geometry form, (c) arrangement method for those searched data, and (d) method to exaggerate the target shape. Human faces and cars were selected as research categories to make the database. According to the survey over the transformed results, it was proved its possibility.

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