• Journal of KIISE:Software and Applications
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• v.30 no.7_8
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• pp.719-726
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• 2003

This paper proposes a multimodal registration method for segmentation of the Visible Human color images, in which color characteristics of bones are very similar to those of its surrounding fat areas. Bones are initially segmented in CT images, and then registered into color images to lineate their boundaries in the color images. For the segmentation of bones in CT images, a thresholding method is developed. The registration method registers boundaries of bodies in CT and color images using a cross-correlation approach, in which the boundaries of bodies are extracted by thresholding segmentation methods. The proposed method has been applied to segmentation of bones in a head and legs whose boundary is ambiguous due to surrounding fat areas with similar color characteristics, and produced promising results.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.55-69
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• 2015

Bandwidth enhancement technique for a proximity coupled patch antenna is investigated. The bandwidth and radiation characteristics of a proximity coupled patch antenna with an integrated impedance matching network printed on substrates with various dielectric constants and thicknesses are compared to those of a proximity coupled patch antenna without an impedance matching network. The bandwidth of a proximity coupled patch antenna with an integrated impedance matching network is greatly increased than that of a proximity coupled patch antenna without an impedance matching network without the degradation of radiation characteristics.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.81-84
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• 2003

부분방전시험은 고전압 고정자 권선의 절연상태를 검사, 평가 할 수 있는 중요한 수단이다. 전동기와 발전기에서 일어나는 절연 악화의 징후로써 부분방전이 발생되며 이러한 부분방전 신호를 검출하기 위한 센서로 SSC(Stator Slot Couple)를 사용한다. 하지만 현재 사용되고 있는 대부분의 SSC의 경우 설계에 있어 특성 임피던스가 실제구조에서 정확히 고려되지 않는 경향이 있다. 실제로 고정자 슬롯에 부착된 마이크로스트립 센서의 특성 임피던스는 정확히 50옴으로 정합 되지 않으며 이것은 센서의 성능에 중요한 영향을 미치게 된다. 그러므로 본 논문에서는 부분방전 센서의 성능을 개선시키기 위해 결합 전송선로(Coupled transmission line)를 이용한 임피던스 정합회로를 제안하고자 한다. 제안된 센서의 성능을 입증하기 위하여 고정자 슬롯에 설치된 기존의 SSC와 임피던스 정합회로를 부착한 센서를 시뮬레이션 한 후 비교 분석하였다. 결과적으로 제안된 정합 회로는 광대역 임피던스 정합 특성을 가지며 임피던스 부정합때문에 일어나는 기존 SSC의 성능 악화를 개선할 수 있었다.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.211-216
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• 2008

Gap fillar antennas are needed for serving the high quality of DMB through the cellular phone by eliminating the shadow regions among buildings or underground. We implement Quadrifilar Helical Antenna using phase difference with PCB feeding lines without coaxial cables and four impedance matching circuits. It is shown that the antenna characteristics is affected by the size and diameter through the simulation process using MicroWave Studio and it is applied for implementing QHA. Experiment results confirm that the performance can be gained as same as the simulation data by using the phase difference with PCB feeding lines without additional impedance matching circuits.

• Journal of KIISE:Software and Applications
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• v.29 no.11
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• pp.767-774
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• 2002

Conventional research on image restoration has focused on restoring degraded images resulting from image formation, storage and communication, mainly in the signal processing field. Related research on recovering original image information of caption regions includes a method using BMA(block matching algorithm). The method has problem with frequent incorrect matching and propagating the errors by incorrect matching. Moreover, it is impossible to recover the frames between two scene changes when scene changes occur more than twice. In this paper, we propose a method for recovering original images using EBMA(Extended Block Matching Algorithm) and a region compensation method. To use it in original image recovery, the method extracts a priori knowledge such as information about scene changes, camera motion and caption regions. The method decides the direction of recovery using the extracted caption information(the start and end frames of a caption) and scene change information. According to the direction of recovery, the recovery is performed in units of character components using EBMA and the region compensation method. Experimental results show that EBMA results in good recovery regardless of the speed of moving object and complexity of background in video. The region compensation method recovered original images successfully, when there is no information about the original image to refer to.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.569-577
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• 1999

A wideband RF receiver for satellite mobile communications system was fabricated and evaluated of performance in low noise amplifier and high gain amplifier. The low noise amplifier used to the resistive decoupling and self-bias circuits. The low noise amplifier is fabricated with both the RF circuits and the self-bias circuits. Using a INA-03184, the high gain amplifier consists of matched amplifier type. The active bias circuitry can be used to provide temperature stability without requiring the large voltage drop or relatively high-dissipated power needed with a bias stabilized resistor. The bandpass filter was used to reduce a spurious level. As a result, the characteristics of the receiver implemented here show more than 55 dB in gain, 50.83 dBc in a spurious level and less than 1.8 : 1 in input and output voltage standing wave ratio(VSWR), especially the carrier to noise ratio is a 43.15 dB/Hz at a 1 KHz from 1537.5 MHz.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.85-92
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• 2009

This paper proposes a full-search block-matching motion estimation circuit with hybrid architecture combining systolic arrays and adder trees for an MPEG-4 encoder. The proposed circuit uses systolic arrays for motion estimation with a small number of clock cycles and adder trees to reduce required circuit resources. The interpolation circuit for 1/2 pixel motion estimation consists of six adders, four subtracters and ten registers. We improved the circuit performance by resource sharing and efficient scheduling techniques. We described the motion estimation circuit for integer and 1/2 pixels at RTL in Verilog HDL. The logic-level circuit synthesized by using 130nm standard cell library contains 218,257 gates and can process 94 D1($720{\times}480$) image frames per second.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.5
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• pp.65-73
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• 2017

In this paper, we propose a stereo matching method to improve the image quality at the hole and the disparity discontinuity regions. The stereo matching method extracts disparity map finding corresponding points between stereo image pair. However conventional stereo matching methods have a problem about the tradeoff between accuracy and precision with respect to the length of the baseline of the stereo image pair. In addition, there are hole and disparity discontinuity regions which are caused by textureless regions and occlusion regions of the stereo image pair. The proposed method extracts initial disparity map improved at disparity discontinuity and miss-matched regions using modified AD-Census-Gradient method and adaptive weighted cost aggregation. And then we conduct the disparity map refinement to improve at miss-matched regions, while also improving the accuracy of the image. Experimental results demonstrate that the proposed method produces high-quality disparity maps by successfully improving miss-matching regions and accuracy while maintaining matching performance compared to existing methods which produce disparity maps with high matching performance. And the matching performance is increased about 3.22(%) compared to latest stereo matching methods in case of test images which have high error ratio.

• Journal of KIISE:Software and Applications
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• v.37 no.11
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• pp.859-865
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• 2010

In this paper, a new method for finger vein recognition is proposed. Researchers are recently interested in the finger vein recognition since it is a good way to avoid the forgery in finger prints recognition and the inconveniences in obtaining images of the iris for iris recognition. The vein images are processed to obtain the line shaped vein images through the local histogram equalization and a thinning process. This thinned vein images are processed for matching, using a new matching algorithm, named HS(HeeSung) matching algorithm. This algorithm yields an excellent recognition rate when it is applied to the curve-linear images processed through a thinning or an edge detection. In our experiment with the finger vein images, the recognition rate has reached up to 99.20% using this algorithm applied to 650finger vein images(130person ${\times}$ 5images each). It takes only about 60 milliseconds to match one pair of images.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.50-59
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• 2000

Stereo vision is a technique extracting depth information from stereo images, which are two images that view an object or a scene from different locations. The most important procedure in stereo vision, which is called stereo matching, is to find the same points in stereo images. It is difficult to match stereo images in real time because stereo matching requires heavy calculation. In this Paper we design a digital VLSI to Process stereo matching in real time, which we call stereo image match processor (SIMP). For implementation of real time stereo matching, sliding memory and minimum selection tree are presented. SIMP is designed with pipeline architecture and parallel processing. SIMP takes 64 gray level 64$\times$64 stereo images and yields 8 level 64 $\times$64 disparity map by 3 bit disparity and 12 bit address outputs. SIMP can process stereo images with process speed of 240 frames/sec.