• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1996.06a
• /
• pp.209-212
• /
• 1996

In this paper, we propose to re-size images using an oblique projection operator instead of the orthogonal one in order to obtain faster, simpler, and more general algorithms. The main advantage is that it becomes perfectly feasible to use higher order models(e.g., splines of degree n 3). We develop the theoretical background and present a simple and practical implementation procedure that uses B-splines. Experiments show that the proposed algorithm consistently outperforms the standard interpolation method and that it essentially provides the same performance as the optimal procedure (least squares solution) with considerably less computations.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10b
• /
• pp.1848-1853
• /
• 1991

To solve the nonlinear system problems, many methods have been proposed. Generally those methods however need long processing time because of their complicated algorithms. On the other hand, some simple linearization methods also have been studied. In this paper, a new linearization method using cubic splines[1] is proposed. The approximated linear system obtained by this method we can apply the conventional simple linear system theories such as Kalman filter[2, 3] for the estimation problem.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.3 no.1
• /
• pp.81-98
• /
• 1999

In spite of the well developed theory and the practical use of the univariate B-spline, the theory of multivariate B-spline is very new and waits its practical use. We compare in this article the multivariate B-spline approximation with the polynomial approximation for the surface fitting. The graphical and numerical comparisons show that the multivariate B-spline approximation gives much better fitting than the polynomial one, especially for the surfaces which vary very rapidly.

• Communications of the Korean Mathematical Society
• /
• v.26 no.1
• /
• pp.89-98
• /
• 2011

The Fourier series has a rapid oscillation near end points at jump discontinuity which is called the Gibbs phenomenon. There is an overshoot (or undershoot) of approximately 9% at jump discontinuity. In this paper, we prove that a bunch of series representations (certain nonharmonic Fourier series) give good approximations vanishing Gibbs phenomenon. Also we have an application for approximating some shape of upper part of a vehicle in a different way from the method of cubic splines and wavelets.

• Communications of the Korean Mathematical Society
• /
• v.11 no.2
• /
• pp.525-538
• /
• 1996

In the course of working on the preconditioning of $C^1$-bicubic collocation method, one has to deal with the $C^1$-bicubic splines. In this paper we are concerned with $C^1$-bicubic spline interpolant for a given function. We construct a basis for the space of $C^1$-bicubic splines for a given partition and find the $C^1$-bicubic spline interpolant for a given function defined on a set.

• Journal of the Korean Data and Information Science Society
• /
• v.18 no.1
• /
• pp.97-105
• /
• 2007

We consider a nonparametric additive risk model that is based on splines. This model consists of both purely and smoothly nonparametric components. As an estimation method of this model, we use the weighted least square estimation by Huller and Mckeague (1991). We provide an illustrative example as well as a simulation study that compares the performance of our method with the ordinary least square method.

• Journal of applied mathematics & informatics
• /
• v.20 no.1_2
• /
• pp.157-169
• /
• 2006

We study properties concerning approximation of fuzzy-number-valued functions by fuzzy B-spline series. Error bounds in approximation by fuzzy B-spine series are obtained in terms of the modulus of continuity. Particularly simple error bounds are obtained for fuzzy splines of Schoenberg type. We compare fuzzy B-spline series with existing fuzzy concepts of splines.

• Communications of the Korean Mathematical Society
• /
• v.10 no.2
• /
• pp.483-490
• /
• 1995

A parametric cubic spline interpolating at fixed number of nodes is constructed by formulating a parametric cubic $g^2$ B-splines $S_3(t)$ with not equally spaced parametric knots. Since the fact that each component is in $C^2$ class is not enough to provide the geometric smoothness of parametric curves, the existence of $S_3(t)$ oriented toward the modified second-order geometric continuity is focalized in our work.

• 한국데이터정보과학회:학술대회논문집
• /
• 2006.11a
• /
• pp.49-50
• /
• 2006

We consider a nonparametric additive risk model that are based on splines. This model consists of both purely and smoothly nonparametric components. As an estimation method of this model, we use the weighted least square estimation by Huffer and McKeague (1991). We provide an illustrative example as well as a simulation study that compares the performance of our method with the ordinary least square method.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.4
• /
• pp.205-215
• /
• 2006

Pen-input displays, such as LCD tablets and tablet PCs, are already popular for its usability in CAD design, in particular. in concept design phase. We propose an intuitive B-Spline modification scheme that can be used for the CAD systems targeting for such devices. Differently from the control point based modification schemes for the B-splines, our scheme relates user pen marking to determining the final shape of the target curve and surface. This, eventually, reduces time for interacting with the shape parameters (i.e., by control points or direct manipulators), which has been regarded as an unavoidable routine tasks for design. To prove its usability, we made an experiments with selected subjects who have been working for industrial design.