• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.163-165
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• 2006

This paper presents a implementation of speed sensorless vector control algorithm of induction motor using MATLAB/SIMULINK amd dSPACE DSl104 R&D board. The estimation of rotor flux linkage and rotor speed is carried out using model reference adaptive system(MRAS) method. Estimated rotor speed is used to speed controller of induction motor. Simulation results are presented to confirm speed sensorless vector control algorithm.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.517-518
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• 2020

이 연구는 3D 그래픽의 로프 시뮬레이션이나 3D 캐릭터의 포니테일 등 Joint들이 복잡하게 꼬이는 상황에서Joint들의 Up-Vector에 대해 이상적으로 꼬이지 않는(Twist-free) 회전을 계산하는 연구이다. 꼬이지 않는 방향은 이상적인 기준점이 될 수 있어서 Twist 연출에 다양한 응용을 할 수 있는 시발점이 된다.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.545-556
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• 2015

A HEVC-compatible 3D video coding method (3D-HEVC) has been recently developed as an extension of the high efficiency video coding (HEVC) standard. In order to efficiently deal with the multi-view video plus depth (MVD) format, 3D-HEVC exploits an inter-component prediction which allows the prediction between texture and depth map images in addition to a temporal prediction used in the conventional single layer video coding such as H.264/AVC and HEVC. The performance of the inter-component prediction is normally affected by the accuracy of the disparity vector, and thus it is important to have an accurate disparity vector used for the inter-component prediction. This paper, therefore, introduces a disparity derivation method and inter-component algorithms using the disparity vector for the efficient 3D video coding. Simulation results show that the 3D-HEVC provides higher coding performance compared with the simulcast approach using HEVC and the simple multi-view extension (MH-HEVC).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.317-326
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• 2008

This paper presents a vector control implementation for SPMSM(Surface-mounted Permanent Magnet Synchronous Motor) using dSPACE 1104 system and MATLAB/SIMULINK. SPMSM can be treated as a DC motor provided that currents of flux and torque component are controlled independently using vector control. Therefore various control algorithms for conventional DC motor control can be adopted to SPMSM. The system is designed to improve set-point tracking capability, fast response, and accuracy In This paper, d-q equivalent modeling of PMSM is derived based on vector control theory. PI controller is used for speed control and decoupling PI controller is used for current control. For the implementation of high performance vector control system, dSPACE 1104 system is used. Experiments were carried out to examine validity of the proposed vector control implementation.

• Korean Journal of Computational Design and Engineering
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• v.13 no.1
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• pp.1-7
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• 2008

Data compression becomes increasingly an important issue for reducing data storage spaces as well as transmis-sion time in network environments. In 3D geometric models, the normal vectors of faces or meshes take a major portion of the data so that the compression of the vectors, which involves the trade off between the distortion of the images and compression ratios, plays a key role in reducing the size of the models. So, raising the compression ratio when the normal vector is compressed and minimizing the visual distortion of shape model's shading after compression are important. According to the recent papers, normal vector compression is useful to heighten com-pression ratio and to improve memory efficiency. But, the study about distortion of shading when the normal vector is compressed is rare relatively. In this paper, new normal vector compression method which is clustering normal vectors and assigning Representative Normal Vector (RNV) to each cluster and using the angular deviation from actual normal vector is proposed. And, using this new method, Visually Undistinguishable Lossy Compression (VULC) algorithm which distortion of shape model's shading by angular deviation of normal vector cannot be identified visually has been developed. And, being applied to the complicated shape models, this algorithm gave a good effectiveness.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.8
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• pp.1187-1193
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• 2013

In this paper, we present realistic 3D head modeling and facial expression systems. For 3D head modeling, we perform generic model fitting to make individual head shape and texture mapping. To calculate the deformation function in the generic model fitting, we determine correspondence between individual heads and the generic model. Then, we reconstruct the feature points to 3D with simultaneously captured images from calibrated stereo camera. For texture mapping, we project the fitted generic model to image and map the texture in the predefined triangle mesh to generic model. To prevent extracting the wrong texture, we propose a simple method using a modified interpolation function. For generating 3D facial expression, we use the vector muscle based algorithm. For more realistic facial expression, we add the deformation of the skin according to the jaw rotation to basic vector muscle model and apply mass spring model. Finally, several 3D facial expression results are shown at the end of the paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.298-301
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• 2008

Vector Graphics describes an image with mathematical statements instead of pixel information, Which enables easy scalability without loss in image quality and usually results in a much smaller file size compared with bitmap images. In this paper, we propose Vector Graphics Rasterizer for mobile device with scan-line edge flag algorithm. Proposed Vector Graphics Accelerator was verified with OpenVG 2D Vector image. The estimated performance of proposed Accelerator is 5 frame per second with Tiger image.

• Computers and Concrete
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• v.2 no.5
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• pp.345-366
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• 2005

This work presents an assessment of the computational performance of a vector-parallel implementation of probabilistic model for concrete cracking in 3D. This paper shows the continuing efforts towards code optimization as reported in earlier works Paz, et al. (2002a,b and 2003). The probabilistic crack approach is based on the direct Monte Carlo method. Cracking is accounted by means of 3D interface elements. This approach considers that all nonlinearities are restricted to interface elements modeling cracks. The heterogeneity governs the overall cracking behavior and related size effects on concrete fracture. Computational kernels in the implementation are the inexact Newton iterative driver to solve the non-linear problem and a preconditioned conjugate gradient (PCG) driver to solve linearized equations, using an element by element (EBE) strategy to compute matrix-vector products. In particular the paper analyzes code behavior using OpenMP directives in parallel vector processors (PVP), such as the CRAY SV1 and CRAY T94. The impact of the memory architecture on code performance, and also some strategies devised to circumvent this issue are addressed by numerical experiment.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1457-1460
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• 1987

2-D shape matching algorithm is proposed which uses pivot vector and componentwise adaptive convergence factor. It is proved that proposed algorithm has better result than any other algorithm. It is to be expected that this algorithm will work effectively in 3-D shape matching.

• Journal of Digital Contents Society
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• v.16 no.4
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• pp.575-581
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• 2015

This paper presents the development of certain highly efficient and accurate method for computing tangent curves for three-dimensional vector fields. Unlike conventional methods, such as Runge-Kutta method, for computing tangent curves which produce only approximations, the method developed herein produces exact values on the tangent curves based upon piecewise linear variation over a tetrahedral domain in 3D. This new method assumes that the vector field is piecewise linearly defined over a tetrahedron in 3D domain. It is also required to decompose the hexahedral cell into five or six tetrahedral cells for three-dimensional vector fields. The critical points can be easily found by solving a simple linear system for each tetrahedron. This method is to find exit points by producing a sequence of points on the curve with the computation of each subsequent point based on the previous. Because points on the tangent curves are calculated by the explicit solution for each tetrahedron, this new method provides correct topology in visualizing 3D vector fields.