• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.61-69
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• 2005

This paper presents an efficient method of extracting line segments from the occupancy grids in a grid map. The grid map is composed of 2-D grids that have both the occupancy and orientation probabilities using sonar sensors. We evaluate the orientation information of every grid when the occupancy probability of the grid is updated from sonar range data. To find the shape of an object in the map from orientation information, the orientations are clustered into several groups according to their values. The line segments are, then, extracted from the clusters based on Hough transform. Finally, a feature-based map is built with these line segments. The proposed method is illustrated with the results produced by sets of experiments in an indoor environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.7
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• pp.1126-1132
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• 2002

In this paper, we propose a new scheme of motion tracking based on fuzzy inference (Fl) and wavelet transform (WT) from image sequences. First, we present a WT to segment a feature extraction of dynamic image . The coefficient matrix for 2-level DWT tent to be clustered around the location of Important features in the images, such as edge discontinuities, peaks, and corners. But these features are time varying owing to the environment conditions. Second, to reduce the spatio-temperal error, We develop a fuzzy inference algorithm. Some experiments are performed 0 testify the validity and applicability of the proposed system As a result, proposed method is relatively simple compared with the traditional space domain method. It is also well suited for motion tracking under the conditions of variation of illumination.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.5
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• pp.85-96
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• 1990

The object of this study is to develop the computer program to predict the transmission loss of a perforated tube muffler with mean flow, and to investigate the influence of porosity and mean flow on the performance of the muffler. The numerical model is made by dividing the muffler into small segments and estimating the transfer matrices for each segment. The computer program is developed for the calculation of the transmission loss of a through-or cross-flow perforated muffler. The experiment is performed for the measurement of the transmission loss and/or the pressure drop for various porosity and flow velocity. From the comparison between computation and experiment, is known that the numerical model agrees well with the experimental result. The effect of porosity and flow velocity on the acoustic performance and the flow resistance of a muffler is presented.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.10
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• pp.1234-1243
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• 1988

In this paper, a target tracking algorithm using the centroid of moving edges is presented. It aims to avoid the difficulty of image segmentation in case of extracting the centroid from only one frame. The proposed algorithm can more easily segment the target than the conventional one in images with complex background. Moreover, it can track the target well when the target is occluded by an object. The result of applying it to a real-time target tracker is shown to be comparatively good.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.47-52
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• 2001

Rapid Prototyping(RP) has been widely applied in designing and developing process of new products. RP can reduce the lead time and expense required to bring a new product form initial concept to production. Among several RP process can dramatically reduce the total build time and be applied for fabrication of large-sized and free form object because it uses in LOM the paper thickness is 0.05∼0.38mm as deposition feature segment. In this study, mechanical properties of pattern with LOM system is studied for optimal design of sand mold casting. The main result is that tensile, compressive strength and pattern size are significantly affected by temperature of hot roll.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.5
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• pp.483-488
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• 2008

An active omni-directional raging system using an omni-directional vision with structured light has many advantages compared to the conventional ranging systems: robustness against external illumination noise because of the laser structured light and computational efficiency because of one shot image containing $360^{\circ}$ environment information from the omni-directional vision. The omni-directional range data represents a local distance map at a certain position in the workspace. In this paper, we propose a matching algorithm for the local distance map with the given global map database, thereby to localize a mobile robot in the global workspace. Since the global map database consists of line segments representing edges of environment object in general, the matching algorithm is based on relative position and orientation of line segments in the local map and the global map. The effectiveness of the proposed omni-directional ranging system and the matching are verified through experiments.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.88-96
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• 1997

As the need of automatized system has been increased recently together with the development of industrial and military technologies, the adaptive real-time target detection technologies that can be embedded on vehicles, planes, ships, robots and so on, are hgihly demanded. Accordingly, this paper proposes a novel approach to detect and segment the moving targets using the binary phase extraction joint transform correlator (BPEJTC), the advanced image subtraction filter and convex hull processing. The BPEJTC which was used as a target detection unit mainly for target tracking compensating the camera movement. The target region has been detected by processing the successful three frames using the advanced image subtraction filter, and has become more accurate by applying the developed convex hull filter. As shown by some experimental results, it is expected that the proposed approaches for compensation of the camera movement and segmentationof of target region, can be used for th emissile guiddance, aero surveillance, automatic inspectin system as well as the target detection unit of automatic target recognition system that request adaptive real-time processing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.217-221
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• 2002

In this paper, we propose a new scheme of motion tracking based on fuzzy inference (FI)and wavelet transform (WT) from image sequences. First, we present a WT to segment a feature extraction of dynamic image . The coefficient matrix for 2-level DWT tent to be clustered around the location of important features in the images, such as edge discontinuities, peaks, and corners. But these features are time varying owing to the environment conditions. Second, to reduce the spatio-temporal error, We develop a fuzzy inference algorithm. Some experiments are peformed to testify the validity and applicability of the proposed system. As a result, proposed method is relatively simple compared with the traditional space domain method. It is also well suited for motion tracking under the conditions of variation of illumination.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.249-250
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• 2007

Background subtraction is a method typically used to segment moving regions in image sequences taken from a static camera by comparing each new frame to a model of the scene background. We present a improved non-parametric background model by null hypothesis. Evaluation shows that this approach achieves very sensitive detection with very low false alarm rates.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.349-351
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• 2012

영상분할은 입력 영상에서 특정 영역을 분할하는 처리로서 이동물체추적, 영상 감시, 영상 기반 제어등 다양한 분야에서 중요하게 다루는 기술 중 한 가지이다. 기존 영상 분할 방법은 영역을 기반으로 하는 방법과 경계선을 기반으로 하는 방법 등이 있으며 경계선을 기반으로 이동물체 영역을 분할하는 것이 연산량 감소등 의 많은 이점이 있다. 그러나 영상의 경계가 모호한 경우 적용이 곤란하다. 본 논문에서는 이동벡터를 추출한 후 이동벡터를 분할기법을 제안하고자 한다. 입력영상에 대하여 BMA기법을 적용하여 이동벡터를 추출하여 이동벡터 영상을 구한 후, 이동 벡터영상에 워터쉐이드 기법을 적용하여 영상 분할하였다. 기존 경계선을 이용한 영상 분할과 비교한 결과 노이즈가 적은 결과를 얻었다.