• Journal of Electrical Engineering and Technology
• /
• v.9 no.6
• /
• pp.2134-2141
• /
• 2014

This paper addresses on a wind power system with BESS(Battery Energy Storage System). The concerned system consists of four parts: the wind speed production model, the wind turbine model, configure capacity of the battery energy storage, battery model and control of the BESS. First of all, we produce wind speed by 4-component composite wind speed model. Secondly, the maximum available wind power is determined by analyzing the produced wind speed and the characteristic curve of wind power. Thirdly, we configure capacity of the BESS according to wind speed and characteristic curve of wind speed-power. Then, we propose a control strategy to track the power reference. Finally, some simulations have been demonstrated to visualize the feasibility of the proposed methodology.

• 제어로봇시스템학회:학술대회논문집
• /
• 1987.10a
• /
• pp.780-785
• /
• 1987

The measuring point data of clay model are widely used to design parts whose external features are important design factor such as automobiles and general die products. This paper presents a method for improving the process to generate smooth surfaces from the measuring point data using turnkey CAD/CAM system. The process of smooth-surface generation involves several steps: styline finding, curve fairing, surface generation and filleting. The process is improved by automatic curve fairing, local correction of surface and multi-boundary surface treatment. An automobile bumper and a telephone receiver are measured and modeled to test the new method. Significant time saving is resulted by changing interactive mode to automatic mode and eliminating inefficient loop of surface generation process.

• Structural Engineering and Mechanics
• /
• v.3 no.6
• /
• pp.541-553
• /
• 1995

The determination of the stress intensity factors is investigated by using the surface integral defined around the crack tip of the structure. In this work, the integral method is derived naturally from the standard path integral J. But the use of the surface integral is also extended to the case where body forces act. Computer program for obtaining the stress intensity factors $K_I$ and $K_{II}$ is developed, which prepares input variables from the result of the conventional finite element analysis. This paper provides a parabolic smooth curve function. By the use of the function and conventional element meshes in which the aspect ratio (element length at the crack tip/crack length) is about 25 percent, relatively accurate $K_I$ and K_{II}$ values can be obtained for the outer integral radius ranging from 1/3 to 1 of the crack length and for inner one zero.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.3
• /
• pp.575-591
• /
• 2011

We present a novel active contour-based two-pass approach to extract smooth feature regions from a triangular mesh. In the first pass, an active contour formulated in level-set surfaces is devised to extract feature regions with rough boundaries. In the second pass, the rough boundary curve is smoothed by minimizing internal energy, which is derived from its curvature. The separation of the extraction and smoothing process enables us to extract feature regions with smooth boundaries from a triangular mesh without user's initial model. Furthermore, smooth feature curves can also be obtained by skeletonizing the smooth feature regions. We tested our algorithm on facial models and proved its excellence.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.1
• /
• pp.32-42
• /
• 1999

Approximate lofting or skinning is one of practical surface modeling techniques well used in CAD and reverse engineering applications. Presented in this paper is a method for approximately lofting a given set of curves wihin a specified tolereance. It is based on refitting input curves simultaneously on a common knot vector and interpolating them to get a resultant NURBS surface. A concept of reducing the number of interior knots of the common knot vector is well adopted to acquire more compact representation for the resultant surface. Energy minimization is newly introduced in curve refitting process to stabilize the solution of the fitting problem and get more fair curve. The proposed approximate lofting provides more smooth surface models and realizes more efficient data reduction expecially when the parameterization and compatibility of input curves are not good enough. The method has been successfully implemented in a new CAD/CAM product VX Vision? of Varimetrix Corporation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.544-547
• /
• 2008

Navigation in 3D virtual environment(VE) is very difficult because the virtual environment is lack information than real 3D world. So navigation is import research subject in 3D VE. In this paper, we study tour path setting method using spline curve. The spline curve is augmented polynomial function. So the curve is differentiable. In particular, since the curves which are order of 2 and 3 are second order differentiable those are sufficiently smooth for using the computer graphics and CAD system.

• International Journal of CAD/CAM
• /
• v.6 no.1
• /
• pp.65-71
• /
• 2006

Based on the smoothness criterion of minimum curvature variation of the curve, tangent angle constraints guaranteeing an optimized geometric Hermite (OGH) curve both mathematically and geometrically smooth is given, and new methods for constructing composite optimized geometric Hermite (COH) curves are presented in this paper. The comparison of the new methods with Yong and Cheng's methods based on strain energy minimization is included.

• Bulletin of the Korean Mathematical Society
• /
• v.48 no.1
• /
• pp.105-114
• /
• 2011

In this paper, we classify (C, $\cal{L}$) such that a smooth curve C of genus g has a nonspecial very ample line bundle $\cal{L}$ of deg $\cal{L}$ = 2g-2-a failing to be normally generated, in terms of the number a.

• Journal of the Chungcheong Mathematical Society
• /
• v.23 no.2
• /
• pp.197-206
• /
• 2010

We study the restriction estimate of Fourier transform to arbitrary convex curves in $R^2$ with no regularity assumption. Assuming that the convex curve has the lower bound of curvatures, we extend the restriction results from smooth convex curves to arbitrary convex curves. Our work has been motivated by the lecture notes of Terence Tao. The bilinear approach and geometric observations play an important role.

• Journal of Korea Multimedia Society
• /
• v.21 no.2
• /
• pp.181-187
• /
• 2018

Line-laser beams are used for depth measurement of welding beads along the circumference of a pipe. For this, first we project a line-laser beam on an rotating pipe and take a sequence of images of the beam projected on the pipe using a CCD camera. Second, the projected line laser beam in each image is detected, converted into a thin curve. Finally measure the distance between the thinned curve and an imaginary line. When a line-laser beam is projected to a rough metal surface such as arc welding beads, the beam is severely scattered. This severe scattering makes the thinned curve perturbed. In this paper, we propose a thinning method robust against scattering of line lasers. First, we extract a projected line laser beam region using an adaptive threshold. Second, we model a thinned curve with a spline curve with control points. Next, we adjust the control points to fit the curve to the projected line-laser beam. Finally, we take a weighted mean of thin curves on a sequence of image frames. Experiments shows that the proposed thinning method results in a thinning curve, which is smooth and fit to the projected line-laser beam with small error.