• Journal of Information Display
• /
• v.7 no.1
• /
• pp.30-34
• /
• 2006

A sub-field rearrangement driving method has been proposed to reduce a DFC (Dynamic False Contour) phenomenon in plasma display panels. The proposed driving method expresses 256 gray levels with 16 sub-fields, while conventional one uses only 8 sub-fields. Notwithstanding the increase in the number of sub-fields, the display time is similar to the conventional 8 sub-fields driving method by appropriate choosing selective writing and selective erasing for sub-fields.

• Progress in Medical Physics
• /
• v.7 no.2
• /
• pp.79-90
• /
• 1996

In this paper, we present an automatic threshold decision method to detect the contour of the a 2-D echocarodiogram by using the Bayes estimator for the boundary-like region. The boundary-like region is constructed from the conduction coefficient of the heat anisotro-pic diffusion method which enforces the blurred image during the preprocessing step. For the boundary-like region, we used the Bayes estimator to select an optimal threshold level. From this threshold value, the contour of the echocardigrams can be detected automatically Finally by overlapping the estimated contour to the original echocardiogram, we can obtain the contour enforced ultrasound echocardiogram.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.18 no.2
• /
• pp.181-192
• /
• 2014

In this paper, we propose a robust real-time myocardial border tracking algorithm for echocardiography. Commonly, after an initial contour of LV border is traced at one or two frame from the entire cardiac cycle, LV contour tracking is performed over the remaining frames. Among a variety of tracking techniques, optical flow method is the most widely used for motion estimation of moving objects. However, when echocardiography data is heavily corrupted in some local regions, the errors bring the tracking point out of the endocardial border, resulting in distorted LV contours. This shape distortion often occurs in practice since the data acquisition is affected by ultrasound artifacts, dropout or shadowing phenomena of cardiac walls. The proposed method deals with this shape distortion problem and reflects the motion realistic LV shape by applying global deformation modeled as affine transform partitively to the contour. We partition the tracking points on the contour into a few groups and determine each affine transform governing the motion of the partitioned contour points. To compute the coefficients of each affine transform, we use the least squares method with equality constraints that are given by the relationship between the coefficients and a few contour points showing good tracking results. Many real experiments show that the proposed method supports better performance than existing methods.

• Journal of Intelligence and Information Systems
• /
• v.8 no.2
• /
• pp.105-115
• /
• 2002

This paper proposed a recognition method of english calling card using both 4-directed contour tracking algorithm and enhanced ART1 algorithm. After we extract candidate character string region using horizontal smearing and 4-directed contour tracking method, we extract character string region through comparison of character region and non-character region using horizontal and vertical ratio and area in english calling card. In extracted character string region, we extract each character using horizontal smearing and contour tracking algorithm, and recognize each character by enhanced ART1 algorithm. The proposed ART1 algorithm is enhanced by dynamic control of similarity using fuzzy sum connective operator. The result indicate that the proposed method is superior in performance.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.378-383
• /
• 2001

In order to improve automobile maneuverability and tire durability, it is very important for one to determine a suitable sidewall contour producing the ideal tension and strain-energy distributions. In order to determine such a sidewall contour, one must apply multi-objective optimization technique. The optimization problem of tire carcass contour involves several objective functions. Hence, we execute the tire contour optimization for improving the maneuverability and the tire durability using satisficing trade-off method. And, the tire optimization also requires long cup time for the sensitivity analysis. In order to resolve this numerical difficulty, we apply neural network algorithm.

• Journal of the Korean Data and Information Science Society
• /
• v.15 no.4
• /
• pp.717-729
• /
• 2004

The contour method which was originally designed for $2{\times}2{\times}2$ contingency table is studied for $2{\times}2{\times}K$ and $2{\times}3{\times}K$ tables. Whereas a contour plot for a $2{\times}2{\times}K$ table is represented on unit squared two dimensional plane, a contour plot of a $2{\times}3{\times}K$ table can be expressed with a regular hexahedron on three dimensional space. Based on contour plots for categorical data fitted to all possible three dimensional log-linear models, one might identify whether $2{\times}2{\times}k$ or $2{\times}3{\times}K$ tables are collapsible over the third variable.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.1
• /
• pp.123-130
• /
• 2000

In this paper, we propose an extracting method of moving object contour using active contour model from image sequences acquired by fixed camera. We use an adaptive background model for robust processing in surrounding conditions. Object segmentation model detects pixels thresholded from local difference image between background and current image and extracts connected regions. Noises in boundary area of moving object we eliminated by morphological filter. The contour of segmented object is corrected by using active contour model for extracting accurate boundary of moving object. We apply the proposed method to highway image sequences and show the results of simulation.

• Proceedings of the KSME Conference
• /
• 2000.04a
• /
• pp.446-451
• /
• 2000

In this paper, a new adaptive cross-coupling control (CCC) algorithm with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

• Journal of Biomedical Engineering Research
• /
• v.13 no.2
• /
• pp.115-124
• /
• 1992

An algorithm has been proposed for the automatic detection of optimal epiand endocardial left ventricular borders from 2-D short axis echocardiogram which is degraded by noise and echo drop out. For the implementation of the algorithm, we modified Ballard's Generalized Hough Transform which can be applicable only for deterministic object border, and newly proposed Fuzzy Hough Transform method. The algorithm presented here allows detection of object whose exact shapes are unknown. The algorithm only requires an approximate model of target object based on anatomical data. To detect the approximate epicardial contour of left ventricle, Fuzzy Hough Transform was applied to the echocardiogram. The optimal epicardial contour was founded by using graph searching method which contains cost function analysis process. Using this optimal epicardial contour and average thickness imformation of left ventricular wall, the approximate endocardial line was founded, and graph searching method was also used to detect optimal endocardial contour.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.791-794
• /
• 2001

We described a method resonant mode identification in dielectric-disc loaded cylindrical cavity resonators. The characteristic equation is solved by using the ContourPlot graph of Mathematica. Contour graph method uses graphical method. It is comparable with numerical method. The numerical method is very difficult a mode identification. The analysis based on the approximated electromagnetic representation. This kinds of studies only concentrated on the calculation of resonant frequencies, and a mode identification of resonant frequencies have not been covered. But, the contour graph method to analyze the characteristic equations is simple and all parts of resonant frequency graph can be easily drawn, it is possible to calculate precise resonant frequencies and to identify the mode of resonant frequencies.