• ETRI Journal
• /
• v.32 no.4
• /
• pp.630-633
• /
• 2010

In this letter, we propose a novel polygonal approximation of digital curves that preserve original shapes. The proposed method first detects break points, which have two different consecutive vectors, and sets an initial dominant point set. The approximation is then performed iteratively by deleting a dominant point using a novel distance, which can measure both the distance and the angle acuteness. The experimental results show that the proposed method can preserve original shapes and is appropriate for various shapes, including slab-sided shapes.

• Journal of KIISE:Software and Applications
• /
• v.32 no.9
• /
• pp.868-877
• /
• 2005

Arcs are usually treated as significant features in the field of pattern recognition. This paper presents a method to detect arcs from digital planar curves and estimate their arc centers and radii by using geometric analysis. The deviation of distance between the original curve and the detected arc by the proposed method does not exceed a tolerant error. The experimental results show that the proposed method is available for the detection of arcs iron not only smooth but also heavily noisy curves.

• Journal of the Korean Magnetics Society
• /
• v.14 no.3
• /
• pp.109-113
• /
• 2004

GMR isolator was modeled using a Wheatstone bridge which is profitable for transmitting rectangular wave digital data, and the output voltage characteristics in relation to the input current were investigated in time domain. GMR isolator modeling was divided into two parts, namely magnetic and electric parts. The flow chart of the modeling was drawn in which measured MR curve of the spin valves were incorporated to obtain the electrical voltage output. For magnetic modeling, 3-dimensional model of planar coil was analyzed by FEM method to obtain the magnetic field strength corresponding to the input current. For electric modeling, resistance, inductance and capacitance of the planar coil were calculated and magnetic field waveform was obtained corresponding to the coil current waveform in time domain. Finally, MR-H curves of spin valves and the magnetic field waveform at the spin valves were composited to obtain the output voltage waveform of the isolator. Even though the amplitude of the coil current waveform was increased by 100％, decreased by 90％, or delayed by 10％ of the period compared with the input current, similar transmitted output voltage waveform to the input current waveform was obtained due to hysteretic characteristics of the spin valves at the transmission speed of over 400 Mbit/s.

• Journal of KIISE
• /
• v.44 no.11
• /
• pp.1194-1208
• /
• 2017

A traditional average smoothing method is designed for smoothing out noise, which, however, unintentionally results in smooth corner points on the curvature accompanied with a shrinkage of curves. In this paper, we propose a novel curve smoothing method via polygonal approximation of the input curve. The proposed method determines the smoothing weight for each point of the input curve based on the angle and approximation error between the approximated polygon and the input curve. The weight constrains a displacement of the point after smoothing not to significantly exceed the average noise error of the region. In the experiment, we observed that the resulting smoothed curve is close to the original curve since the point moves toward the average position of the noise after smoothing. As an application to digital cartography, for the same amount of smoothing, the proposed method yields a less area reduction even on small curve segments than the existing smoothing methods.