• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.301-306
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• 2004

이 논문에서는 1m 해상도 위성영상에서 관측할 수 있는 여러 인공지물 중에서 아파트 및 산업용 건물 등, 비교적 중대형이고 사각형 형태인 건물들을 반자동으로 추출하기 위한 알고리즘을 소개한다. 기존에 연구된 건물추출을 위한 방식으로는 Perceptual Grouping, 스테레오 분석, LIDAR 센서 등에서 얻은 3 차원 정보를 이용하는 방식 등이 있다. 여기서는 단일영상 만을 이용하여 반자동으로 건물을 추출하는 알고리즘을 제안한다 이 알고리즘은 먼저 영상으로부터 라인을 추출한 후, 라인분석을 통하여 건물의 위치와 방향을 결정하고, 탬플릿 정합을 이용하여 이를 개선한다. 그리고 자동으로 추출된 건물외각선에 포함된 오류를 제거하기 위하여 수동편집 단계를 수행한다. 또한 먼저 수행한 건물추출 결과를 활용하여 주변에 유사한 형태의 건물외각선을 빠르게 추출하기 위해 기존에 추출된 건물 외각선 Polygon 을 탬플릿으로 정의하고 정합을 수행하여 건물 외각선을 추출한다. 개발된 알고리즘은 기존의 다른 방식들에 비해 추가적인 영상이나 정보를 요구하지 않고도 빠른 시간에 정확한 사각형형태의 건물을 추출할 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.4
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• pp.617-623
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• 2018

In this paper, we propose a novel seamless video composition method based on shape matching and Poisson equation. Video composition method consists of video segmentation process and video blending process. In the video segmentation process, the user first sets a trimap for the first frame, and then performs a grab-cut algorithm. Next, considering that the performance of video segmentation may be reduced if the color, brightness and texture of the object and the background are similar, the object region segmented in the current frame is corrected through shape matching between the objects of the current frame and the previous frame. In the video blending process, the object of source video and the background of target video are blended seamlessly using Poisson equation, and the object is located according to the movement path set by the user. Simulation results show that the proposed method has better performance not only in the naturalness of the composite video but also in computational time.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.434-444
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• 2002

본 논문에서는 기존의 RF 여파기가 대역 내에서만 정합이 되는 특성을 개선하여 대역 외에서도 50$\Omega$ 정합 특성을 가지는 여파기 설계 기술을 제안하였다. 대역 외에서 정합 시켜 주는 방법으로 결합기와 대역 통과 여파기로 구성된 Balance Type과 결합기와 대역 저지 여파기로 대역 통과 여파기 특성을 가지는 Reflection Type을 제시하여 그 특성을 확인하였다. 각각의 형태는 광대역 90도 3-㏈ 결합기를 사용한 것으로 결합기의 대역폭과 진폭 및 위상 오차에 따라 저지 대역에서의 정합 특성이 좌우되며, 이에 광대역의 3-㏈ 결합기를 설계 및 적용하여 광대역의 반사 손실 개선 효과를 얻을 수 있었다. 제작 결과 Balance type의 경우 1.2 GHz~2.6GHz까지 대역 내에서 -10㏈에서 -15 ㏈의 반사 손실 특성을 가지고 대역 저지 특성이 우수하며, Reflection type은 DC에서 3.3GHz까지 반사손실이 -15 ㏈ 내외로 광대역 정합 특성을 가진다. 특히, 저주파 반사 특성이 우수하여 저주파 발진 가능성이 큰 회로 설계에 유용하다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.5
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• pp.69-75
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• 2001

In this paper, a fast and easy impedance matching method, which could give the impedance matching component for the general 1 or 2-port network was introduced. First, the entire network structure was defined which consists of the network part to be matched and the impedance matching part composed of inductors and capacitors. Next, the transmission matrix and input and output impedances of the entire network from the terminal impedance conditions were calculated, then the exact solutions for the matching components were obtained. To verify the efficiency of this method, this method was applied to the CDMA If band withdrawal weighted SAW transversal filter, and investigated the effects of the impedance matching before and after, through the simulation and experiment. As the result, the performance of a fractional bandwidth of 1.2%, insertion loss of 29 dB, and VSWR of 80 have improved to a factional bandwidth of 1.8％, insertion loss of 9 dB, VSWR of 3 at 85.38 MHz center frequency. The result shows that this impedance matching method could be used in the SAW devices and other types of 1 or 2-port network.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.1
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• pp.60-69
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• 1999

Motion compensation by affine transform has been proposed as a solution to the artifact problems in very low bit rate video coding and a HMA(Hexagoanl Matching Algorithm) has been proposed for refine motions estimation. When dividing images with an affine transform, as image objects do not necessarily conform to triangle patterns. In this paper we propose a method that first divides an image into triangular patches according to its edge information and then further divides the image into more detailed triangular patches where more complicated edge information occurs. We image propose a PMA(Polygona Matching Algorithm) for refine motion estimation because of the different triangle pattern types of neighboring blocks and its performance is compared with H.263.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.602-608
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• 2005

We have studied to obtain the SAW filter for the Single Phase Unidirectional Transduce. (SPUDT), was formed on the Langasite substrate and was evaporated by Aluminum-Copper alloy and then we performed computer-simulated by simulator. We can fabricate that the block weighted type IDT as an input transducer of the filter and the withdrawal weighted type IDT as an output transducer of the filter from the results of our computer-simulations. Also, we have performed to obtain the properly conditions about impedance matching of the SAW filter for SPUDT. We have employed that the number of pairs of the input and output IDT are 50 pairs and the thickness and the width of reflector are 5000A and $3.6{\mu}m$, respectively. And the width of IDT' fingers is $2.4{\mu}m$, and the space between IDT' finger and reflector is $2.0{\mu}m$. Frequency response of the fabricated SAW filter has the property that the center frequency is about 190MHz and bandwidth at the 3dB is probably 7.7MHz after when we have matched impedance. Also, we could obtain that ripple characteristics is less than 0.4dB and standing wave ratio is probably 1.5 after when we have matched impedance.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.176-183
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• 2013

We propose a rolled fingerprint merging algorithm that effectively merges plain fingerprints in consecutive frame units that are fed through rolling and detects more fingerprint minutiae in order to increase the fingerprint recognition rate. The proposed rolled fingerprint merging algorithm uses a adaptive projection mask; it contains a detector that separates plain fingerprints from the background and a projection mask generator that sequentially projects the detect ed images. In addition, in the merging unit, the pyramid-shaped projection method is used to detect merged rolled fingerprints from the generated variable projective mask, starting from the main images. Simulations show that the extracted minutia e are 46.79% more than those from plain fingerprints, and the proposed algorithm exhibits excellent performance by detecting 52.0% more good fingerprint minutiae that are needed for matching.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.2
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• pp.73-78
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• 2004

By modeling the block matching algorithm as a function of the correlation of image blocks, we derive search patterns for fast block matching motion estimation. The proposed approach provides an analytical support lot the diamond-shape search pattern, which is widely used in fast block matching algorithms. We also propose a new fast motion estimation algorithm using adaptive search patterns and statistical properties of the object displacement. In order to select an appropriate search pattern, we exploit the relationship between the motion vector and the block differences. By changing the search pattern adaptively, we improve motion prediction accuracy while reducing required computational complexity compared to other fast block matching algorithms.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1178-1188
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• 2003

In this paper, we describe image mosaicing techniques for constructing a large high-resolution image with images taken by a video camera in hand. we propose the method which is automatically retrieving the exact matching area using color information and shape information. The proposed method extracts first candidate areas which have similar form using a Voronoi Distance Matching Method which is rapidly estimating the correspondent points between adjacent images, and calculating initial transformations of them and finds the final matching area using color information. It is a method that creates Voronoi Surface which set the distance value among feature points and other points on the basis of each feature point of a image, and extracts the correspondent points which minimize Voronoi Distance in matching area between an input image and a basic image using the binary search method. Using the Levenberg-Marquadt method we turn an initial transformation matrix to an optimal transformation matrix, and using this matrix combine a basic image with a input image.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1361-1366
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• 2006

본 논문에서는 제약되지 않은 카메라에서 얻어진 회전과 크기 변화를 가진 영상들을 특징 기반의 보로노이 거리 매칭 방법을 이용하여 고속으로 합성 하는 기법에 관해 기술한다. 기존의 특징점 기반 매칭 기법들이 사람의 개입에 의해 영상을 정합하거나, 크기나 회전 변화를 고려하지 않은 형태의 영상들을 처리하는 것과 달리 회전이나 크기변화요소가 포함된 입력영상들을 사람의 개입이 없이 자동으로 정확한 중첩영역을 빠르게 검색하는 방법을 제안한다. 제안된 방법은 우선 영상내의 특징 점들의 위상 정보와 특징 점들 사이의 거리 정보를 가지는 보로노이 거리 정합법을 통해 대응점을 구하고, 찾아진 대응 쌍들을 이용하여 2차원 투영의 초기 변환행렬을 구한다. 다음으로 비선형 이승오차 최적화 알고리즘을 이용하여 최적의 변환 행렬을 구한 후, 마지막으로 구해진 변환 행렬을 이용하여 영상을 합성한다. 실험결과를 통해 본 논문에서 제안한 방법의 효율성을 보인다.