• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.262-263
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• 2015

본 논문에서는 마이크로소프트 키넥트 센서를 이용한 실시간 성능의 3차원 환경 복원 알고리즘을 소개한다. 기존의 멀티키넥트 시스템을 확장하여 총 열두대의 키넥트를 사용하는데, 키넥트의 높은 대역폭 문제를 해결하기 위하여 키넥트가 여섯 대씩 연결된 두 대의 데스크탑을 UDP 통신으로 연결하였고, 각 키넥트로부터 들어오는 3차원 포인트클라우드로부터 확률적인 3차원 환경복원을 하기 위하여 옥토맵 알고리즘을 차용하였다. 또한, GPU를 연산에 활용함으로써 실시간 성능을 확보하였다.

• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.79-88
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• 1997

This paper introduces a new energy function, as maximum a posteriori(MAP) estimate of binocular disparity, that can deal with both random dot stereo-gram(RDS) and natural scenes. The energy function uses phase-magnitude as features to detect only the shift for a pair of corrupted conjugate images. Also we adopted Fleet singularity that effectively detects unstable areas of image plant and thus eliminates in advance error-prone stereo mathcing. The multi-scale concept is applied to the multi laser architecture that can search the solutions systematically from coarse to fine details and thereby avoids drastically the local minima. Using mean field approximation, we obtained a compact representation that is suitable for fast computation. In this manner, the energy function satisfies major natural constraints and requirements for implementing parallel relaxation. As an experiment, the proposed algorithm is applied to RDS and natural stereo images. As a result we will see that it reveals good performance in terms of recognition errors, parallel implementation, and noise characteristics.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.156-159
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• 1993

In this paper, computerized BEAM (brain electrical activity map) was implemented for objective and quantitative multichannel EEG analysis. BEAM is calculated by 4 point Interpolation method and number of elements are 5140. Representation methods of BEAH are two. One is dot density method which classify brain electrical potential 9 levels by dot density and the other is color method which classify brain electrical 12 levers by different colors. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.93-100
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• 1994

5-axis CNC machining is being used in the manufacturing of tire mold, screw, and turbine blade because it can produce complex workpiece more efficiently and accurately than 3-axis CNC machining does. However, it is difficult to calculate the CL data in 5-axis CNC machining. This paper describes an efficient method to modify and edit the NC code and a data structure for representation of the workpiece produced by 5-axis CNC machining. Wireframe display of tool path and shading display of workpiece are used to represent verification results. Machining errors can be evaluated quantitively using the data structure based on the workpiece data model. The methods are implemented in a program with a IBM-PC and MS-Windows.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.473-474
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• 2011

Image quantization 기술은 영역 평탄화 기술중 하나로서 NPR과 같은 컴퓨터 그래픽스 분야에서 널리 쓰이고 있는 기술 중 하나이다. 하지만 기존의 image quantization은 중요부분을 고려하지 않기 때문에 detail한 칼라 정보를 가지는 주요 영역이 있는 경우에는 그 결과가 좋지 못한 단점을 가지고 있다. 본 논문에서는 이러한 단점을 극복하기 위해, Sailency map을 이용해 영상의 주요 영역을 고려한 image Flattening 기법을 제안한다. 제안한 방법은 검출된 주요 영역을 좀 더 세분화해서 표현하므로 기존의 방법과 비교해 좀 더 좋은 결과를 보여준다.

• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.188-195
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• 2024

This paper proposes a photorealistic real-time dense 3D mapping system that utilizes a neural network-based image enhancement method and mesh-based map representation. Due to the characteristics of the underwater environment, where problems such as hazing and low contrast occur, it is hard to apply conventional simultaneous localization and mapping (SLAM) methods. At the same time, the behavior of Autonomous Underwater Vehicle (AUV) is computationally constrained. In this paper, we utilize a neural network-based image enhancement method to improve pose estimation and mapping quality and apply a sliding window-based mesh expansion method to enable lightweight, fast, and photorealistic mapping. To validate our results, we utilize real-world and indoor synthetic datasets. We performed qualitative validation with the real-world dataset and quantitative validation by modeling images from the indoor synthetic dataset as underwater scenes.

• Advances in materials Research
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• v.13 no.3
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• pp.203-210
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• 2024

Science mapping is a visual representation of the structure and dynamics of scholarly knowledge. Gas adsorption on catalyst supports is a crucial process in many catalytic reactions. The R package "Bibliometrix" and VosViewer software were employed for science mapping analysis. The results show that the upward trend but fluctuates from year to year for both annual scientific production and average article citations per year. Co-occurrence of the keywords were used to identify the primary fields of study and to map the existing state of research. Trending topics reveal some interesting features that support the growth of research in this field and are associated with emerging disciplines or areas of study that have not been extensively explored.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.372-378
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• 2014

Noise in biomedical X-ray image degrades the quality so that it might causes to decrease the accuracy of diagnosis. Especially the noise reduction techniques is quite essential for low-dose biomedical X-ray images obtained from low radiation power in order to protect patients, because their noise level is usually high to well discriminate objects. This paper proposes an efficient method to remove the noise in low-dose X-ray images while preserving the edges with diverse resolutions. In the proposed method, a noisy image is at first decomposed into several images with different resolutions in pyramidal representation, then the stable map of edge confidence is obtained from each of analyzed image using a fuzzy logic-based edge detector. This map is used to adaptively determine the parameter for guided filters, which eliminate the noise while preserving edges in the corresponding image. The filtered images in the pyramid are extended and synthesized into a resulted image using interpolation technique. The superiority of proposed method compared to the median, bilateral, and guided filters has been experimentally shown in terms of noise removal and edge preserving properties.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.3
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• pp.184-193
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• 2010

This paper proposes a biological iridescence BRDF(Bidirectional Reflectance Distribution Function) compression and rendering method. In the graphics technology, iridescence sometimes is named structure colors. The main features of these symptoms are shown transform of color and brightness by varying viewpoint. Graphics technology to render this is the BRDF technology. The BRDF methods enable realistic representation of varying view direction, but it requires a lot of computing power because of large data. In this paper, we obtain reflection map from iridescence BRDF, analyze color of reflection map and propose representation method by several colorfully concentric circle. The one concentric circle represents beam width of reflection ray by one normal vector. In this paper, we synthesize rough concentric by using several virtually optical normal vectors. And we obtain spectrum information from concentric circles passing through the center point. The proposed method enables IBR(image based rendering) technique which results is realistic illuminance and spectrum distribution by one texture from reduced BRDF data within spectrum.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.143-150
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• 2013

The purpose of this study is to suggest the methodology to develop variable-scale network model, which is able to induce large-scale road network in detailed level corresponding to small-scale linear objects with various abstraction in higher level. For this purpose, the definition of terms, the benefits and the specific procedures related with a variable-scale model were examined. Second, representation level and the components of layer to design the variable-scale map were presented. In addition, rule-based data generating method and indexing structure for higher LoD were defined. Finally, the implementation and verification of the model were performed to road network in study area (Jeju -do) so that the proposed algorithm can be practical. That is, generated variable scale road network were saved and managed in spatial database (Oracle Spatial) and performance analysis were carried out for the effectiveness and feasibility of the model.