• Title/Summary/Keyword: Coordinates transformation

Search Result 270, Processing Time 0.028 seconds

Efficiency of Rotational Operators for Geometric Manipulation of Chain Molecules

  • Seok, Chaok;Coutsias, Evangelos A.
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.10
    • /
    • pp.1705-1708
    • /
    • 2007
  • Geometric manipulation of molecules is an essential elementary component in computational modeling programs for molecular structure, stability, dynamics, and design. The computational complexity of transformation of internal coordinates to Cartesian coordinates was discussed before.1 The use of rotation matrices was found to be slightly more efficient than that of quaternion although quaternion operators have been widely advertised for rotational operations, especially in molecular dynamics simulations of liquids where the orientation is a dynamical variable.2 The discussion on computational efficiency is extended here to a more general case in which bond angles and sidechain torsion angles are allowed to vary. The algorithm of Thompson3 is derived again in terms of quaternions as well as rotation matrices, and an algorithm with optimal efficiency is described. The algorithm based on rotation matrices is again found to be slightly more efficient than that based on quaternions.

Polar-coordinates Linear Interpolation for Map Contour Reconstruction at Summit Area (정상 영역의 등고선 재구성을 위한 극좌표계 선형보간)

  • Hwang Dong-Kuk;Jun Byung-Min;Park Cheon-Joo
    • The Journal of the Korea Contents Association
    • /
    • v.5 no.1
    • /
    • pp.127-134
    • /
    • 2005
  • To connect the gap on the contours at the summit area, we propose the linear interpolation in the polar coordinates. Tn the experiments of applying both existing algorithms and a proposed method to some graphic images, the proposed method generated curves that average MAE was 1.940 pixels. In particular, our method with MAE of 1.240 on real map image was superior than the others. Also by generating new curves with neighbors-resembled appearance, the contours were reconstructed seamlessly.

  • PDF

Adaptive control with neural network for a magnetic levitation system

  • Hao, Shuang-Hui;Yang, Zi-Jiang;Tsuji, Teruo
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1994.10a
    • /
    • pp.195-200
    • /
    • 1994
  • This paper presents a nonlinear adaptive control approach to a 4-point attraction magnetic levitation system using the local coordinates transformation and neural network. Based on local coordinates transformations, the magnetic levitation system can be represented in a state magnetic levitation system can be represented in a state space from of a 4-input 4-output. Neural networks which are defined in the new coordinates are used to learn the nonlinear functions of the system which are defined in the new coordinats also. The parameters of the neural networks are updated in an on-line manner according to an augmented tracking error. The simulation results are reported in this paper.

  • PDF

Development of Registration Algorithm considering Coordinate Weights for Automobile Sub-Frame Assembly (가중치를 고려한 자동차 서브프레임의 인증 알고리즘 구현)

  • Lee, Kwang-Il;Yang, Seung-Han;Lee, Young-Moon
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.3 no.4
    • /
    • pp.7-12
    • /
    • 2004
  • Inspection and analysis are essential process to determine whether a completed product is in given specification or not. Analysis of products with very complicated shape is difficult to carry out direct comparison between inspected coordinate and designed coordinates. So process called as matching or registrations is needed to solve this problem. By defining error between two coordinates and minimizing the error, registration is done. Registration consists of translation, rotation and scale transformations. Error must be defined to express feature of inspected product. In this paper, registration algorithm is developed to determine pose of sub-frame at assembly with body of automobile by defining error between two coordinates considering geometric feature of sub-frame.

  • PDF

A Study on the Pattern Recognition of Hole Defect using Neural Networks (신경회로망을 이용한 원공 결함 패턴 인식에 관한 연구)

  • 이동우;홍순혁;조석수;주원식
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.2
    • /
    • pp.146-153
    • /
    • 2003
  • Ultrasonic inspection of defects has been focused on the existence of defect in structural material and need has much time and expenses in inspecting all the coordinates (x, y) on material surface. Neural networks can have an application to coordinates (x, y) of defects by multi-point inspection method. Ultrasonic inspection modeling is optimized by neural networks Neural networks has trained training example of absolute and relative coordinate of defects, and defect pattern. This method can predict coordinates (x, y) of defects within engineering estimated mean error $\psi$.

Development of the Process of Coordinate Transformation of Local Datum Cadastral Map to the World Geodetic System - Using Adjusted Coordinate - (지적도면의 세계측지계 좌표변환 프로세스에 대한 연구 - 조정좌표의 활용을 통해서 -)

  • Yang, Chul Soo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.32 no.spc4_2
    • /
    • pp.401-412
    • /
    • 2014
  • This study is purposed on showing an effective process for coordinate transformation of cadastral maps, based on the local datum, in the World Geodetic System (WGS) for Cadastral Reform Project (CRP). The process follows three steps: coordinate adjustment, datum transformation and distortion modeling. The first procedure is that point coordinates on local datum has to be adjusted by those GPS observed point-to-point distances, using trilateration. Secondly, the adjusted coordinates need to be transformed to WGS by applying the Affine model, while the verification of the methodology is implemented under numerical experiments. To conduct this procedure, 195 points in the same coordinate origins in Seoul and 61 points in several different origins in Incheon are used in the estimation. As a result, there are less than 2cm coordinate differences between transformed coordinates and measured ones at everywhere. Also, it is remarkable that the transformation does not depend on either of the particular common points or the sizes of computed region. Therefore, this suggested methodology is expected to easily provide identifications and corrections for points-deviations for improved quality of the cadastral map by distortion modeling through CRP.

Improvment of Accuracy of Projective Transformation Matrix for Image Mosaicing (영상 모자이킹을 위한 사영 변환 행렬의 정밀도 개선)

  • 노현영;이상욱
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2002.11a
    • /
    • pp.226-230
    • /
    • 2002
  • This paper proposes a method of improvement of accuracy of projective transformation matrix for Image Mosaicing. Using shift theorem, we extracted global translation components between images and using translation components, we found matching points between images so we solve general matching point problem we extracted highly trusted matching point using RANSAC algorithm. we normalized matching point coordinates and improved accuracy of projective transformation matrix.

  • PDF

A Study on the Characteristics of the Coordinates Transformation between Ellipsoids on the Area Measured by GPS (GPS 측위범위에 따른 타원체간의 좌표변환특성 연구)

  • 이용창;강준묵
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.13 no.2
    • /
    • pp.153-162
    • /
    • 1995
  • The coordinate transformation both WGS84 and Bessel ellipsoids is essential to use of GPS in South Korea. Especially, for transformation considered the needed accuracy and the regional characteristics, the study about geoid modeling and the characteristics on the transformed area should be done. The aim of this study define the characteristics of the transformed coordinates according to transformation methods and the area measured by GPS. For this, large network that include South Korea, four regional network consist of large network, and local net-work include Incheon city designed. Geoid model based on Bessel suitable to South Korea selected from study about the effects of the assumed geoid height at the geodetic origin, and then coefficients computed according as transformed area and methods. Also, the transformed characteristics of the large coefficients, the regional coefficients, and the local coefficients according to methods compared, analyzed synthetically.

  • PDF

Fast Geometric Transformations of 3D Images Represented by an Octree (8진트리로 표현된 3차원 영상의 빠른 기학학적 변환)

  • Heo, Yeong-Nam;Park, Seung-Jin;Kim, Eung-Gon
    • The Transactions of the Korea Information Processing Society
    • /
    • v.2 no.6
    • /
    • pp.831-838
    • /
    • 1995
  • Geometric transformations require many operations in displaying moving 3D objects on the screen and a fast computation is a important problem in CAD or animation applications. The general method to compute the transformation coordinates of an object represented by an octree must perform the operations on every node. This paper proposes an efficient method that computes the rectangular coordinates of the vertices of the octree nodes into the coordinates of the universe space using the basicvectors in order to compute quickly geometric transformations of 3D images represented by an octree. The coordinates of the vertices of each octant are computed by using the formula presented here, which requies additions and multiplications by powers of 2. This method has a very fast execution time and is compared with the general computation method.

  • PDF

A Study on the Stifness of Coil Spring in the Three Dimensional Space (3차원 공간에서 코일스프링의 강성에 관한 연구)

  • 이수종
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.25 no.5
    • /
    • pp.1130-1139
    • /
    • 2001
  • Springs are widely utilized in machine element. To find out stiffness of coil spring, the space beam theory using the finite element method is adopted in this paper. In three dimensional space, a space frame element is a straight bar of uniform cross section which is capable of resisting axial forces, bending moments about two principal axes in the plane of its cross section and twisting moment about its centroidal axis. The corresponding displacement degrees of freedom are twelve. The displacements of nodal points due to small increment of force are calculated by the finite element method and the calculated nodal displacements are added to coordinates of nodal points. The new stiffness matrix of the system using the new coordinates of nodal points is adopted to calculated the another increments of nodal displacements, that is, the step by step method is used in this paper. The results of the finite element method are fairly well agreed with those of various experiments. Using MATLAB program developed in this paper, spring constants can be predicted by input of few factors.

  • PDF