• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.341-344
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• 2001

본 논문에서는 학습을 수행하여 뇌 MR 이미지를 자동으로 분류하고 검색하는 시스템을 설계하였다. 이미지로부터 얻을 수 있는 정보는 크게 두 가지 부류로 나눌 수 있다. 이미지 자체로부터 얻을수 있는 크기, 색상, 질감, 윤곽선 등의 하위레벨(low-level) 정보가 있고, 이미지 의미 해석에서 오는 전이, 포함, 방향, 등의 상위레벨(high-level) 정보가 있다. 이 논문은 의료 이미지에 대하여 상위 및 하위 레벨 정보의 각 특징을 살리고 효과적으로 검색하기 위해, 두 부류의 이미지 정보에 대한 결정 트리(Decision Tree) 학습을 2 단계로 적용하여 이미지를 분류하도록 시스템을 설계하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.254-259
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• 2000

데이터 웨어하우스는 다양하고 서로 다른 저장소로부터 데이터를 수집하고 통합하는 역할을 담당한다. 그리고 의사결정 지원이나 OLAP 질의에 대한 효과적인 구현을 목적으로 하나 또는 그 이상의 저장소의 데이터에 대한 구체화된 뷰들을 저장 관리한다. 데이터 웨어하우스를 둘러싸고 있는 화제로는 구조, 알고리즘, 그리고 다양한 데이터베이스들 또는 다른 정보 저장소들로부터 데이터를 추출하여 가져와 하나의 저장소(Data Warehouse)에 저장하는 툴들이 있다. 최근 몇 년간 데이터 웨어하우스는 데이터베이스 업계에서 두드러진 분야로 성장하였다. 그러나 데이터베이스 연구 공동체는 제한되어 왔다. 본 논문에서는 일반적인 데이터 웨어하우스 구조의 윤곽을 잡고 데이터 웨어하우스를 위해 데이터를 수집하고 변형하고 통합하는 시스템 설계를 목적으로 한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.362-365
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• 2006

본 논문에서는 인간 로봇 상호 작용을 위해 정확한 스켈레톤 특징점을 추출하는 강인한 추출기를 설계한다. 제안된 특징점 추출기는 인간의 움직임 정보로부터 얻어진 색상, 윤곽선, 시간차 정보 및 가상 신체 모델을 이용하여 정확한 특징점 위치를 찾아낸다. 또한 특징점 추출에 소요되는 탐색 시간을 줄이기 위해 격자박스를 이용한 원형 탐색 기법을 도입하였다. 최종적으로 기법의 우수성을 확인하기 위해 다양한 동작의 특징점 추출 실험을 수행하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.7
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• pp.1038-1046
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• 2004

In order to acquire high-speed and high-precision performances in servomechanisms, an integrated design method have been proposed. Based on strict mathematical modeling and analysis of system performance according to design and operating parameters, a nonlinear constrained optimization problem including the relevant subsystem parameters of the servomechanism is formulated. Optimum design results of mechanical and electrical parameters are obtained according to the design parameters specified by designers through the integrated design processes. Motors are optimally selected from the servo motor database. Both the geometric errors referring to Abbe offset and the contour errors are minimized while required constraints such as stability conditions and saturated conditions are satisfied. This design methodology both offers the improved possibility to evaluate and optimize the dynamic motion performance of the servomechanism and improves the quality of the design process to achieve the required performance for high-speed/precision servomechanisms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.92-101
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• 2005

It is difficult to detect the accurate detection which leads the camera it moves follows in change of the noise or illumination and Also, it could be recognized with backgound if the object doesn't move during hours. In this paper, the proposed method is updating changed background image as much as N＊M pixel mask as time goes on after get a difference between imput image and first background image. And checking image pixel can efficiently detect moving by computing fixed distance pixel instead of operate all pixel. Also, set up minimum area of object to use boundary point of object abstracted through checking image pixel and motion detect of object. Therefore motion detection is available as is fast and correct without doing checking image pixel every Dame. From experiment, the designed and implemented system showed high precision ratio in performance assessment more than 90 percents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.7
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• pp.1203-1212
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• 1994

This paper proposes a variable block size vector quantization based on a biorthogonal wavelet transform for image compression. An image is first decomposed with the biorthogonal wavelet transform into multiresolution image and the wavelet coefficients of the middle frequency bands are segmented using the quadtree sturcture to extract the perceptually important regions in the middle frequency bands. A sedges of middle frequency bands exist the corresponding position of high frequency bands, the complicated quadtree structure of middle frequency bands is equally applied to the high frequency bands. Therefore the overhaed information of the quadtree codes needed to segment the high frequency bands can be reduced. The segmented subblocks are encoded with the codebook designed at the each scales and directions. The simulation results showed that the proposed methods could reproduce higher quality image with bit rate reduced about 20(%) than of the preceding VQ method and sufficiently reduce the bolck effect and the edge degradation.

• Journal of KIISE:Databases
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• v.32 no.5
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• pp.498-508
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• 2005

A shape data is used one oi most important feature for image retrieval as data to reflect meaning of image. Especially, structural feature of shape is widely studied because it represents primitive properties of shape and relation information between basic units well. However, most structural features of shape have the problem that it is not able to guarantee an efficient search time because the features are expressed as graph or tree. In order to solve this problem, we generate curvature-based morphological graph, End design key to cluster shapes from this graph. Proposed this graph have contour features and morphological features of a shape. Shape retrieval is accomplished by stages. We reduce a search space through clustering, and determine total similarity value through pattern matching of external curvature. Various experiments show that our approach reduces computational complexity and retrieval cost.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.407-416
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• 2006

It is difficult for the movement detection of an object through a camera to detect exact movement because of unnecessary noises and changes of the light. It can be recognized as a background, when there is no movement after the inflow of an object. Therefore, It is necessary to fast search algorithm for tracking and extract of object that is realtime image. In this thesis, we evaluate the difference of the input vision based on initial image and replace some pixels in process of time. When there is a big difference between background image and input image, we decide it is the point of the time of the object input and then extract boundary point of it. The extracted boundary point detects precise movement of the object by creating minimum block of it and searching block that maintaining distance. The designed and embodied system shows more than 95% accuracy in the performance test.

• Journal of Sensor Science and Technology
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• v.11 no.2
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• pp.93-101
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• 2002

The quality of agricultural products is classified with various factors which are measured and determined by destructive and/or nondestructive method. NIR spectrum analysis method is used to determine internal qualities such as a brix and an acidity. CCD color camera is used to measure external quality like color and a size of fruit. Today, nondestructive methods are widely researched. The quality and the grade of fruit loaded into a cup automatically and measured in real time by camera and NIR system is determined by infernal and external factors. This paper proposes modified boundary tracking algorithm which detects the contour of fruit's color image and make chain code faster than conventional method. The chain code helps compute a size of fruit image and find multiple loading of a fruit in single cup or fruit between two cups. The designed classification system sorts a citrus at speed of 8 fruit/s, with evaluating a brix, an acidity and a size grade.

• The KIPS Transactions:PartB
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• v.14B no.3 s.113
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• pp.191-198
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• 2007

In this paper, we present a marker detection and recognition method from camera image for a disabled person to interact with a server system which can control appliance of surrounding environment. It converts the camera image to a binary image by using multi-threshold and extracts contours of objects in the binary image. After that, it approximates the contours to a list of line segments. It finds rectangular markers by using geometrical features which are extracted from the approximated line segments. It normalizes the shape of extracted markers into exact squares by using the warping technique. It extracts feature vectors from marker image by using principal component analysis and then recognizes the marker. The proposed marker recognition system is robust for light change by using multi-threshold. Also, it is robust for angular variation of camera by using warping technique and principal component analysis. Experimental results show that the proposed method achieves 100% recognition rate at maximum for 21 markers and execution speed of 12 frames/sec.