• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.112-115
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• 2018

본 논문에서는 공간적 일관성과 시간적 일관성을 모두 고려하는 그래프 컷(graph cuts, GC) 알고리즘을 적용한 새로운 비디오 정합(video stitching) 방법을 제안한다. 먼저 입력 비디오로부터 취득한 전체 프레임에 대해서 정렬(frame alignment) 작업이 완료된 후, 프레임 합성(frame composition)을 위한 정합선 찾기(seam finding) 과정을 진행한다. 정합선을 찾는 과정에서 개선된 그래프 컷 알고리즘을 이용해 정렬된 프레임들을 자연스럽게 합성할 수 있는 최적의 정합선을 찾는다. 우선, 첫번째 입력 프레임에서 찾은 최적 정합선을 참조 정합선으로 설정한다. 그 다음, 연속된 프레임들의 정합선 찾기 과정을 수행할 때, 참조 정합선과의 거리 값을 가중치로 이용하는 새로운 비용 함수를 적용한다. 본 논문에서 제안하는 알고리즘으로 찾은 최적 정합선은 입력 프레임의 중첩 영역에 움직이는 물체가 존재할 때, 물체의 모양을 손상시키지 않으면서 동시에 연속된 프레임의 정합선을 유사한 형태로 유지시킨다. 결과적으로 공간적, 시간적 자연스러움이 보장되는 고품질의 비디오 정합 결과를 얻을 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.299-304
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• 1998

초고속 정보통신망에서 ATM 사용자와 ATM 망간의 접속을 위한 ATM 정합장치는 ATM 통신 방식으로 ATM 교환기와 정합하는 각종 정합장치로 구성된다. ATM 정합장치는 155.520 Mbps의 선로 속도를 갖는 기본속도(STM-1 : Synchronous Transport Module-1) 정합장치와 44.736 Mbps의 선로 속도를 갖는 중속(DS-3 : Digital Signal-level 3) 정합장치, 그리고 2.048 Mbps 혹은 1.544 Mbps의 선로 속도를 갖는 저속(DS-l/E) 정합장치, 622.08 Ups의 선로 속도를 갖는 고속(STM4) 정합 장치로 구성된다. 본 논문에서는 ATM 저속, 중속, 기본속도 및 고속 정합장치의 기능 및 구현에 대하여 기술하였다.

• The KIPS Transactions:PartB
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• v.17B no.2
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• pp.115-124
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• 2010

Stereo matching techniques are categorized in two major schemes, local and global matching techniques. In global matching schemes, several investigations are introduced, where cost accumulation is performed in multiple matching lines. In this paper, we introduce a new multi-line stereo matching techniques which expands a conventional single-line matching scheme to multiple one. Matching cost is based on simple normalized cross correlation. We expand the scan-line optimization technique to a multi-line scan-line optimization technique. The proposed technique first generates a reliability image, which is iteratively updated based on the previous reliability measure. After some number of iterations, the reliability image is completed by a hole-filling algorithm. The hole-filling algorithm introduces a disparity score table which records the disparity score of the current pixel. The disparity of an empty pixel is determined by comparing the scores of the neighboring pixels. The proposed technique is tested using the Middlebury and CMU stereo images. The error analysis shows that the proposed matching technique yields better performance than using conventional global matching algorithm.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.9
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• pp.700-704
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• 2009

In this paper, we propose a method for combining MR image with histopathology image of the prostate using image correction and multi-stage registration. Our method consists of four steps. First, the intensity of prostate bleeding area on T2-weighted MR image is substituted for that on T1-weighted MR image. And two or four tissue sections of the prostate in histopathology image are combined to produce a single prostate image by manual stitching. Second, rigid registration is performed to find the affine transformations that to optimize mutual information between MR and histopathology images. Third, the result of affine registration is deformed by the TPS warping. Finally, aligned images are visualized by the intensity intermixing. Experimental results show that the prostate tumor lesion can be properly located and clearly visualized within MR images for tissue characterization comparison and that the registration error between T2-weighted MR and histopathology image was 0.0815mm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.661-668
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• 2012

A coaxial-cable impedance transformer that can be used in high power and wideband frequency range is an arbitrary impedance transformation ratio by an additional coaxial cable. The coaxial-cable impedance transformer to be 50-${\Omega}$ to 25-${\Omega}$ impedance transformation ratio is easily operated an wideband power divider by connecting two 50-${\Omega}$ lines at 25-${\Omega}$ impedance point. This wideband power divider has a poor output matching characteristic and a poor isolation characteristic between two output ports. In this paper, it proposes a coaxial-cable power divider to be a good output matching and isolation characteristics as it uses the singly terminated filter design theory. The odd-mode operation characteristic of the suggested power divider to use singly terminated low pass filter coefficient due to matching order and ripple value is examined by ADS program. And, it fabricates and measures the operation characteristic of 2-way power divider with 2nd-order and 4th-order matching circuit.

• Korean Journal of Materials Research
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• v.5 no.3
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• pp.297-309
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• 1995

본 연구에서는 이온선보조증착법에 의해 Si(100)기판위에 정합성장된 $Si_{0.5}$Ge_{0.5}$층의 핵성성과 성장을 고찰하였다. 성장층에 대한 AFM(Atomic Force Microscopy), RHEED(Reflection High Energy Electron diffraction) 등의 분석결과 Si(100)기판위에 이온선보조증착에 의하여 성장된 $Si_{0.5}$Ge_{0.5}$층은 Stranski-Kranstanov(SK)기구로 성장되며, 300eV, 10 $\mu$A/$cm^{2}$의 Ar이온선을 조사시키는 경우 결정성이 향상되었고, SK 성장 방식의 임계두께가 증가하였다. Ar 이온선 조사에 의해 MBE에 의한 정합성장온도(55$0^{\circ}C$-$600^{\circ}C$)보다 훨씬 낮은 20$0^{\circ}C$에서 정합성장이 가능하였으며, $x_{mn}$값은 10.5%로 MBE에 의한 정합성장시 보고된 $x_{mn}$ 값보다 낮았다. 이온충돌에 의해 발생한 3차원 island의 분해와 표면확산의 증가가 $Si_{0.5}$Ge_{0.5}$층의 성장에 현저한 영향을 미쳤으며, 이온충돌의 영향은 3차원 island의 생성보다 3차원 island의 분해가 더 안정한 낮은 증착온도에서만 관찰되었다.

• Annual Conference on Human and Language Technology
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• 1992.10a
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• pp.225-235
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• 1992

본 논문은 오프라인 필기체 한글 인식에 관한 연구로서, 입력 문자 영상에 대한 위치 정규화, 외곽선 추적 및 세선화의 전처리 과정을 거쳐 외곽선의 방향 성분 분포, 세선화한 결과의 방향 성분 분포, 구조적 특징점 분포 등의 특징을 추출한 다음, 획을 추출하여 획의 방향과 길이에 대한중점 분포 특징으로 정합하는 필기 한글의 인식을 위한 획 정합 방법을 제안하였다. 인식 시간의 단축을 위해 먼저 외곽선의 방향성분분포를 이용하여 대분류하였으며, 한글 사용 빈도수 상위 520자로 구성되는 필기 데이타에 대한 실험 결과, 평균 91%의 인식률과 평균 0.46초의 문자당 인식 시간을 보임으로써 제안된 획 정합 방법이 입력 문자의 잡영이나 획의 기울기에 대한 변형을 효과적으로 흡수할 수 있음을 알 수 있었다.

• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.992-1001
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• 2019

In many applications, images acquired from multiple cameras are stitched to form an image with a wide viewing angle. We propose a method of estimating a seam line using motion information to stitch multiple images without distortion of the moving object. Existing seam estimation techniques usually utilize an energy function based on image gradient information and parallax. In this paper, we propose a seam estimation technique that prevents distortion of moving object by adding temporal motion information, which is calculated from the gradient information of each frame. We also propose a measure to quantify the distortion level of stitched images and to verify the performance differences between the existing and proposed methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.202-207
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• 2016

An auxiliary real-time train communications system among drivers, train-traffic controllers and field workers is necessary to share hazard information (i.e. rockfall detection, track maintenance) in low visibility zones (long tunnels and steep curved track). To develop the appropriate communication system, this paper proposes a new way of power line communication using the rail track (Rail - PLC), which has little noise and distortion of attenuation. Therefore, it is important to measure the impedance of the rail and to apply an impedance matching technique to increase the transmission characteristic of the Rail - PLC. This study would evaluate the reflection and the transmission characteristics of the rail using a network analyzer and an impedance matching transformer. The suitable impedance matching ratio was 1:3.28 from the result of back-to-back testing. The results confirmed that the transformer can improve the performance of the transmission signal in Rail - PLC using an impedance matching technique.

• 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.