• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1995.06a
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• pp.137-141
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• 1995

MASF is a kind of temporal filter proposed for noise reduction and temporal band limitation. MASF uses motion vectors to extract temporal information in spatial domain. Therefore, inaccurate motion information causes some distortions in MASF operation. Currently, bilinear interpolation after MBA(Block Matching Algorithm) is used for the motion estimation sheme of MASF. But, this method results in unreliable estimation when the object in image sequence has larger movement than the maximum displacement assumed in BMA or the input images are severely corrupted with noise. In order to solve this problem, we propose a hierarchical motion estimation algorithm for MASF. Experimental results show that the proposed method produces reliable output under large motion and noisy situations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.414-419
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• 1994

In recent years, there has been an increasing intest in control of active automotive suspension systems with a goal of improving the ride comfort and safety. Many approaches for these purposes have used linearized models of the suspension's dynamics, allowing the use of linear control theory. However, the linearized model does not well descriibe the actual system behavior which is inherently nonlinear. The object of this study is to develop a neuro controlled active suspension for the ride quality improvement. After obtaining active control law using optimal control theory, we use the artificial neural network to train the neuro controller to learn the relation of road input and control force. Form the numerical results, we found that back propagation learning does show good pattern matching and vertical acceleration of the driver's seat and sprung mass.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.1861-1873
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• 1996

This paper describes the content-based image retrieval system that is implemented to retrieve images using constituent rate of lines and Bezier curves. We proposed the line and Bezier curve extraction algorithm which extracts lines and curve that are fitted on the contour information of images. For this extration, it was necessary to remove internal area of the proprocessed object within images and to approximate its contour to polygon, and proposed retrevial algorithm which gets the simularity using the consitituent rate of lines and curves and perform the simularity matching.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.625-629
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• 2014

In this paper, a tile projector for the active control of low-frequency underwater echoes is studied using finite element method. Compared to the existing underwater actuators used for echo reduction, the tile projector is better suited for covering a wide area such as the hull of a submarine. In order to actively match the acoustic impedance at the water-object interface, the projector is driven to radiate a pressure wave that is the inverted replica of the echo at the interface. Finite element simulations demonstrate significant echo reductions due to the active impedance matching by the tile projector.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.249-252
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• 2001

본 논문에서는 실제 물체 윤곽을 검출하기 위해 물체 분할 과정에서 변이(disparity) 정보를 이용한다. 스테레오 정합(stereo matching)으로 획득한 변이도에서 불연 속한 부분은 물체의 경계나 변이가 할당되지 않는 폐색 영역 일부분에서 나타날 수 있으므로, 변이 변화가 작 은 영상의 각 영역은 같은 물체의 일부분이라는 것은 직관적으로 명백하다. 분할 과정은 이러한 변이 정보를 적절하게 이용하고 확산망(diffusion network)을 이용하여 선택적인 확산을 수행한다. 추정된 변이도는 변이 변화가 작은 영역을 인식하기 위해 사용되고 그러한 영 역은 단일 물체의 일부분이거나 배경(background)이라고 간주하고 텍스쳐(texture)에 의한 에지(edge)글 등방성 확산으로 제거하는 과정을 거친다. 나머지 영상 영역에서, 비등방성 확산으로 변이의 변화와 밝기차의 변화를 고려하여 수행된다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.55-58
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• 2012

백내장 수술에서 인공수정체 삽입영역을 표시하고 제어하는 것은 매우 중요하다. 수술시 발생하는 삽입영역 제어의 오차는 시력의 저하를 가져온다. 이를 위해 디지털 이미지 프로세싱을 이용한 많은 추적 방법이 연구 중에 있다. 그 중에서 템플릿 매칭은 실시간성이 뛰어난 객체 추적 방법으로 인공수정체 삽입 영역 추적 방법으로 사용 될 수 있다. 그러나 템플릿 매칭 방법은 입력 영상과 템플릿 영역의 상관관계만을 따지며 추적하기 때문에 추적 할 객체의 물체 겹침 상황이 발생하면 정확한 추적이 불가능하다. 본 논문에서는 템플릿 매칭 방법을 이용하여 인공수정체 삽입 영역을 추적하고 특정 영역의 버퍼들을 사용하여 물체 겹침 상황을 해결하고자 한다.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.333-334
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• 2016

본 논문은 광류와 템플릿 정합을 이용한 장기 객체 추적 기법을 제안한다. 템플릿 정합은 객체의 형태, 크기, 회전 등 변화에 취약하지만, 객체의 변화량이 적은 경우 검출 성능은 우수한 편이다. 동영상의 인접한 프레임들은 객체의 변화량이 크지 않아 템플릿 정합만으로도 검출이 가능하지만, 누적되는 오차로 인해 템플릿의 갱신이 필요하다. 하지만 템플릿 정합만으로는 갱신에 필요한 객체 영역을 특정할 수 없기 때문에, 광류를 이용하여 효과적으로 템플릿을 갱신할 수 있다. 이와 같은 구조의 적응형 템플릿 정합을 적용한 장기 객체 추적 기법을 제안하며, 모의 실험을 통해 장기 객체 추적이 가능함을 증명한다.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.90-95
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• 2010

This paper describes the development of integrated head and eye tracker system. Vision based head tracker is performed and it has 7mm error in 300mm translation. The epi-polar method and point matching are used for determining a position of head and rotational degree. High brightness LEDs are installed on helmet and the installed pattern is very important to match the points of stereo system. Eye tracker also uses LED for constant illumination. A Position of gazed object(3m distance) is determined by pupil tracking and eye tracker has 1~5 pixel error. Integration of result data of each tracking system is important. RS-232C communication is applied to integrated system and triggering signal is used for synchronization.

• Proceedings of the IEEK Conference
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• summer
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• pp.259-262
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• 2004

In most of the character recognition systems, the method of template matching or statistical method using hidden Markov model is used to extract and recognize feature shapes. In this paper, we used modified chain-code which has 8-directions but 4-codes, and made the chain-code of hand-written character, after that, converted it into transition chain-code by applying to HMM(Hidden Markov Model). The transition chain code by HMM is analyzed as signal flow graph by Mason's theory which is generally used to calculate forward gain at automatic control system. If the specific forward gain and feedback gain is properly set, the forward gain of transition chain-code using Mason's theory can be distinguished depending on each object for recognition. This data of the gain is reorganized as tree structure, hence making it possible to distinguish different hand-written characters. With this method, $91\%$ recognition rate was acquired.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.50-53
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• 2000

It is effectively removed noise in the image using FCNN(Fuzzy Cellular Neural Network) applying fuzzy theory to CNN(Cellular Neural Network) structure and HD(Hausdorff Distance) commonly used measures for object matching. HD calculates the distance between two point set of pixels in two-dimensional binary images without establishing correspondence. Also, this method is proposed in order to improve the operation speed. In this paper, $\alpha$-LTSHD(Least Trimmed Square HD) operator applying $\alpha$-Trimmed to LTSHD, one field of HD, is applied to FCNN structure, and it is proposed as the modified method in order to remove noise in the image. Also, it is made a comparison with the other filters by using MSE and SNR after removing noise using the FCNNS which are applied $\alpha$-LTSHD operator through the computer simulation. In a result, FCNN performance which is applied the proposed $\alpha$-LTSHD demonstrated the superiority to the other filters in the noise removal.