• Korean Journal of Mathematics
• /
• v.17 no.3
• /
• pp.315-330
• /
• 2009

Using the fixed point method, we prove the generalized Hyers-Ulam stability of the following cubic-quadratic functional equation $$(0.1)\;\frac{1}{2}(f(2x+y)+f(2x-y)-f(-2x-y)-f(y- 2x))\\{\hspace{35}}=2f(x+y)+2f(x-y)+4f(x)-8f(-x)-2f(y)-2f(-y)$$ in fuzzy Banach spaces.

• Journal of the Korean Mathematical Society
• /
• v.49 no.1
• /
• pp.153-164
• /
• 2012

In this paper, we study the existence, non-existence, and multiplicity of positive solutions for a coupled telegraph system using the xed-point theorem of cone expansion/compression type, the upper-lowe solutions method, and xed point index theory.

• Journal of the Chungcheong Mathematical Society
• /
• v.29 no.3
• /
• pp.453-464
• /
• 2016

In this paper, we investigate the solution of the following functional inequality $$N(f(x)+f(y)+f(z),t){\geq}N(f(x+y+z),mt)$$ for some fixed real number m with $\frac{1}{3}$ < m ${\leq}$ 1 and using the fixed point method, we prove the generalized Hyers-Ulam stability for it in fuzzy Banach spaces.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.23 no.4
• /
• pp.439-444
• /
• 1986

In this paper the PID-B self-tuner[1] is extended to allow a less abrupt response to set point or plant parameter changes and to control a nonminimum phase plant. The proposed extended PID/ST derived from the direct pole-placement PID/ST is obtained with the Bezout identity as the underlying design method. And its control gains are normalized by the integral control gain. Although the integral control gain is normalized to 1 in our scheme, the so-called "set point and derivative kick" can be avoided sufficiently by normalizing the measurement vector and set point.

• Journal of the Chungcheong Mathematical Society
• /
• v.25 no.1
• /
• pp.43-49
• /
• 2012

In this paper, we investigate the stability of a functional equation $$f(x+y+z)-f(x+y)-f(y+z)-f(x+z)+f(x)+f(y)+f(z)=0$$ by using the fixed point theory in the sense of L. $C\breve{a}dariu$ and V. Radu.

• Journal of the Chungcheong Mathematical Society
• /
• v.32 no.1
• /
• pp.113-125
• /
• 2019

In this paper, I investigate the stability of the functional equation f(x + 2y) - 3f(x + y) + 3f(x) - f(x - y) - 3f(y) + 3f(-y) = 0 by using the fixed point theory in the sense of L. $C{\breve{a}}dariu$ and V. Radu.

• The Korean Journal of Applied Statistics
• /
• v.6 no.2
• /
• pp.247-252
• /
• 1993

Consider minimizing the sum of absolute deviations for multiple regression models. If a regression line is assumed to pass a given point, then we can find that the $L_1$ regression coefficient can be defined in terms of the weighted medians of the slopes from each data point to the given point. Therefore, $L_1$ method could be regarded to find the optimal point which regression line passes over.

• Journal of the Korean Data and Information Science Society
• /
• v.9 no.1
• /
• pp.1-9
• /
• 1998

In case of Zero-Inflated Poisson model with a change-point, likelihood ratio test statistic was used for testing hypothesis for a change-point. A change-point and several interesting parameters were estimated by using the method of moments and maximum likelihood. In order to compare the estimators, empirical mean-square-error was used. Real data for the Zero-Inflated Poisson model with a change-point and Poisson model without a change-point were examined.

• International Journal of CAD/CAM
• /
• v.12 no.1
• /
• pp.9-19
• /
• 2012

Generation of optimum planar B-spline curve in terms of minimum deviation and required fairness to approximate a target shape defined by a strip-shaped unorganized 2D point cloud is studied. It is proposed to use the location of control points as variables within the geometric optimization framework of point distance minimization. An adaptive simulated annealing heuristic optimization algorithm is developed to iteratively update an initial approximate curve towards the target shape. The new implementation comprises an adaptive cooling procedure in which the temperature change is adaptively dependent on the objective function evolution. It is shown that the proposed method results in an improved convergence speed when compared to the standard simulated annealing method. A couple of examples are included to show the applicability of the proposed method in the surface model reconstruction directly from point cloud data.

• KIEE International Transaction on Systems and Control
• /
• v.12D no.1
• /
• pp.7-11
• /
• 2002

In this study, fur the shape-based image retrieval, a method using local differential invariants is proposed. This method calculates the differential invariant feature vector at every feature point extracted by Harris comer point detector. Then through vector quantization using LBG algorithm, all feature vectors are represented by a codebook index. All images are indexed by the histogram of codebook index, and by comparing the histograms the similarity between images is obtained. The proposed method is compared with the existing method by performing experiments for image database including various 1100 trademarks.