• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.15 no.2
• /
• pp.253-261
• /
• 1997

In general, the transformation of coordinates in GPS is carried out by 3 dimensional transformation method with 3-10 parameter. In korea, the coordinates of transformation points ware determined are adjusted in-dependently by planimetry and the height, and also the weight of observations were not properly applied to the adjustment. In this study, two different transformation methods are tested and analysed by the field test, and it is finally found that 2 dimensional method is more efficient way than 3 dimensional classical transformation method.

• Korean Journal of Optics and Photonics
• /
• v.17 no.6
• /
• pp.525-531
• /
• 2006

Synthesized 3-D CGH of a general three dimensional object is obtained by using a new 3-D coordinates transformation technique. A CCD camera is used to record several projected images of the 3-D object from different viewing angles. The recorded data are numerically calculated and processed to yield two-dimensional complex functions, which are then encoded fer the final synthesized 3-D CGH.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.29 no.3
• /
• pp.249-255
• /
• 2011

The free-stereo mosaics image without GPS/INS and ground control data can be generated by using relative orientation parameters on the 3D model coordinate system. Its origin is located in one reference frame image. A 3D coordinate calculated by conjugate points on the free-stereo mosaic images is represented on the 3D model coordinate system. For determining 3D coordinate on the 3D absolute coordinate system utilizing conjugate points on the free-stereo mosaic images, transformation methodology is required for transforming 3D model coordinate into 3D absolute coordinate. Generally, the 3D similarity transformation is used for transforming each other 3D coordinates. Error of 3D model coordinates used in the free-stereo mosaic images is non-linearly increased according to distance from 3D model coordinate and origin point. For this reason, 3D model coordinates used in the free-stereo mosaic images are difficult to transform into 3D absolute coordinates by using linear transformation. Therefore, methodology for transforming nonlinear 3D model coordinate into 3D absolute coordinate is needed. Also methodology for resampling the free-stereo mosaic image to the geo-stereo mosaic image is needed for overlapping digital map on absolute coordinate and stereo mosaic images. In this paper, we propose a 3D non-linear transformation for converting 3D model coordinate in the free-stereo mosaic image to 3D absolute coordinate, and a 2D non-linear transformation based on 3D non-linear transformation converting the free-stereo mosaic image to the geo-stereo mosaic image.

• Korean Journal of Applied Biomechanics
• /
• v.12 no.1
• /
• pp.125-133
• /
• 2002

The purpose of this study was to develop a method for estimating 3-D coordinates of lower trunk muscles using orientation angles during a motion. Traditional 3-D motion analysis system with DLT technique was used to track down the locations of eight reference markers which were attached on the back of the subject. In order to estimate the orientations of individual lumbar vertebrae and musculoskeletal parameters of the lower trunk muscle, the rotation matrix of the middle trunk reference frame relative to the lower trunk reference frame was determined and the angular locations of individual lumbar vertebrae were estimated by partitioning the orientation angles (Cardan angles) that represent the relative angles between the rotations of the middle and lower trunks. When the orientation angles of individual intervertebral joints were known at a given instant, the instantaneous coordinates of the origin and insertion for all selected muscles relative to the L5 local reference frame were obtained by applying the transformation matrix to the original coordinates which were relative to a local reference frame (S1, L4, L3, L2, or L1) in a rotation sequence about the Z-, X- and Y-axes. The multiplication of transformation matrices was performed to estimate the geometry and kinematics of all selected muscles. The time histories of the 3-D coordinates of the origin and insertion of all selected muscles relative to the center of the L4-L5 motion segment were determined for each trial.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.10
• /
• pp.886-890
• /
• 2013

In this paper, a 3D coordinates acquisition method for a mechanical assembly is developed by using multiview X-ray images. The multi-view X-ray images of an object are obtained by a rotary table. From the rotation transformation, it is possible to obtain the 3D coordinates of corresponding edge points on multi-view X-ray images by triangulation. The edge detection algorithm in this paper is based on the attenuation characteristic of the X-ray. The 3D coordinates of the object points are represented on a graphic display, which is used for the inspection of a mechanical assembly.

• 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.

• Journal of Korean Society for Geospatial Information Science
• /
• v.2 no.2 s.4
• /
• pp.143-151
• /
• 1994

3-D coordinates that result form GPS survey are not applied directly in korea because they are based on WGS 84 ellipsoid. Thus they must be transformed into longitude, latitude on the Bessel ellipsoid and orthometric height. Transformation parameters must be determined in order to perform the coordinate transformation. Also, coordinate transformation be preformed on longitude, latitude and ellipsoidal height. First estimation of Bessel geoidal height must be accomplished to acquire Bessel ellipsoidal height This paper suggests accuracy of coordinate transformation according to the estimation method of Bessel geoidal height. Also, This paper suggests that Bessel geoidal height have influence on the coordinates transformation.

• Journal of the Korea Convergence Society
• /
• v.2 no.3
• /
• pp.15-23
• /
• 2011

This paper deals with the analysis for the operation characteristic of PV 3 phase inverter, considering the state equation through d-q coordinates transformation, and proposes an algorithm of controlling current using PI(Proportional Integral) controller to control the output and the theory algorithm of sinusoidal PWM method to design inverter. And also this paper performs PV modelling using PSCAD/EMTDC S/W which is commonly used in analysis of distribution system and confirms effectiveness of the modelling proposed in this paper by analyzing and comparing the EMTDC/PSCAD simulation result with the theoretical method.

• Journal of Cadastre & Land InformatiX
• /
• v.46 no.2
• /
• pp.183-196
• /
• 2016

Ground control points are needed for precision geometric correction of satellite images, and the coordinates of a high-quality ground control point can be obtained from the GPS measurement. However, considering the GPS measurement requires an excessive amount o f t ime a nd e fforts, there is a need for coming up with an alternative solution to replace it. Therefore, we examined the possibility of replacing the existing GPS measurement with coordinates available at online maps to acquire the coordinates of ground control points. To this end, we examined error amounts between the coordinates of ground control points obtained through Daum Map API, and them compared the accuracies between three types of coordinate transformation equations which were used for geometric correction of satellite images. In addition, we used the coordinate transformation equation with the highest accuracy, the coordinates of ground control point obtained through the GPS measurement and those acquired through D aum M ap A PI, and conducted geometric correction on them to compare their accuracy and evaluate their effectiveness. According to the results, the 3rd order polynomial transformation equation showed the highest accuracy among three types of coordinates transformation equations. In the case of using mid-resolution satellite images such as those taken by Landsat-8, it seems that it is possible to use geometrically corrected images that have been obtained after acquiring the coordinates of ground control points through Daum Map API.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.55 no.2
• /
• pp.103-109
• /
• 2006

In this paper, the detection scheme of the spatial coordinates based on stereo camera for a intelligent path planning of an automatic mobile robot is proposed. In the proposed system, face area of a moving person is detected from a left image among the stereo image pairs by using the YCbCr color model and its center coordinates are computed by using the centroid method and then using these data, the stereo camera embedded on the mobile robot can be controlled for tracking the moving target in real-time. Moreover, using the disparity mad obtained from the left and right images captured by the tracking-controlled stereo camera system and the perspective transformation between a 3-D scene. and an image plane, depth information can be detected. Finally, based-on the analysis of these calculated coordinates, a mobile robot system is derived as a intelligent path planning and a estimation.