• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.649-652
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• 2007

이 논문에서는 영화, CF 같은 영상물 제작 시 CG/실사 합성을 위해 배경기하정보를 추출하는 알고리즘을 제안한다. Metric Reconstruction 은 카메라 자동 보정을 통해 이루어지며 이는 오랫동안 연구되어 온 분야이다. 접근방법은 영상의 특징점 추적 정보와 카메라 내부변수 가정으로부터 유도되는 자기 보정 방식과 공간상에서 미리 기하 정보를 알고 있는 보정틀을 사용하는 방식으로 크게 분류될 수 있다. CG/실사 합성의 작업 효율성을 위해서는 배경 영상에 보정틀이 보이지 않는 것이 좋은데 자연 특징점(Natural Feature)에만 의존하는 자기 보정 방식의 경우 2K 급 영상에서 CG 객체를 합성했을 때 떨림이 느껴지지 않을 만큼 정확한 결과를 얻기 힘들다. 이 논문에서는 Polleyfeys[2]가 제안하였던 영상 시퀀스를 입력으로 하는 자기 보정 시스템을 바탕으로 마야 작업 환경에서의 핀홀 카메라 모델에 맞도록 카메라 내부변수의 비선형 최적화를 수행하는 방법과 사용자 개입을 통한 카메라 변수 정확도 향상방법을 제안한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.6
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• pp.448-453
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• 1999

원전의 열성층 현상으로 발생하는 열 피로균열 및 입계응력부식균열(IGSCC) 등은 결함에 대해서 검사자의 특별한 관심과 노력 없이는 초음파를 이용해 이러한 종류의 결함검출 및 크기 측정이 쉽지 않다. 이러한 결함의 검출 및 크기 측정을 위해서 먼저 초음파 모드 변환 기법을 사용하여 결함 검출 및 결함 크기를 분류한 후에 결함 끝단에서의 초음파 회절파(tip diffraction)를 이용한 여러 가지의 초음파 기법 둥으로 정확한 결함 크기를 측정하여 가동전 중점검시 발견된 결함의 추적 관리 및 결함평가신뢰도 향상에 기여하고자 한다. 따라서, 여기서는 열 피로균열 및 입계응력부식균열 등과 같은 결함의 정확한 검출 및 크기 측정을 위해 초음파 모드 변환 기법의 특성을 철저히 이해하고 이에 관련된 초음파 신호들을 정확히 구분할 수 있는 방법을 기술하였다.

• Journal of KIISE
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• v.43 no.1
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• pp.13-26
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• 2016

This paper proposes a new sound localization algorithm that can improve localization performance based on a tetrahedron-shaped microphone array. Sound localization system estimates directional information of sound source based on the time delay of arrival(TDOA) information between the microphone pairs in a microphone array. In order to obtain directional information of the sound source in three dimensions, the system requires at least three microphones. If one of the microphones fails to detect proper signal level, the system cannot produce a reliable estimate. This paper proposes a tetrahedron- shaped sound localization system with a coordinate transform method by adding one microphone to the previously known triangular-shaped system providing more robust and reliable sound localization. To verify the performance of the proposed algorithm, a real time simulation was conducted, and the results were compared to the previously known triangular-shaped system. From the simulation results, the proposed tetrahedron-shaped sound localization system is superior to the triangular-shaped system by more than 46% for maximum sound source detection.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.5 s.335
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• pp.13-22
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• 2005

IEEE 802.11a is a standard for the high-speed wireless local area network (WLAN), supporting from 6 up to 54 Mbps in a 5 GHz band. We propose a channel equalization algerian and a sampling clock recovery algorithm by utilizing the Viterbi decoder output of the IEEE 802.11a WLAN standard. The proposed channel equalizer adaptively compensates channel variations. The proposed system uses re-encoded Viterbi decoder outputs as reference symbols for the adaptation of the channel equalizer. It also extracts sampling phase information with the Viterbi decoder outputs for fine adjustment of the sampling clock. The proposed sampling clock recovery and equalizer are more robust to noise and frequency selective fading environments than conventional systems using only four pilot samples.

• Journal of the Korean Society for information Management
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• v.41 no.1
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• pp.261-282
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• 2024

This study proposed and evaluated electroencephalography (EEG)-based and eye-tracking-based methods to determine relevance by utilizing users' implicit relevance feedback while navigating content in a digital library. For this, EEG/eye-tracking experiments were conducted on 32 participants using video, image, and text data. To assess the usefulness of the proposed methods, deep learning-based artificial intelligence (AI) techniques were used as a competitive benchmark. The evaluation results showed that EEG component-based methods (av_P600 and f_P3b components) demonstrated high classification accuracy in selecting relevant videos and images (faces/emotions). In contrast, AI-based methods, specifically object recognition and natural language processing, showed high classification accuracy for selecting images (objects) and texts (newspaper articles). Finally, guidelines for implementing a digital library interface based on EEG, eye-tracking, and artificial intelligence technologies have been proposed. Specifically, a system model based on implicit relevance feedback has been presented. Moreover, to enhance classification accuracy, methods suitable for each media type have been suggested, including EEG-based, eye-tracking-based, and AI-based approaches.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.102-109
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• 2014

A particle system is used for modeling the physical phenomenon. There are many traditional ways for simulation modeling which can be well suited for application including the landscapes of branches, clouds, waves, fog, rain, snow and fireworks in the three-dimensional space. In this paper, we present a new fireworks modeling technique for modeling 3D firework based on Firework Particle Tracking (FPT) using the particle system. Our method can track and recognize the launched and exploded particle of fireworks, and extracts relatively accurate 3D positions of the particles using 3D depth values. It can realize 3D simulation by using tracking information such as position, speed, color and life time of the firework particle. We exploit Region of Interest (ROI) for fast particle extraction and the prevention of false particle extraction caused by noise. Moreover, Kalman filter is used to enhance the robustness in launch step. We propose a new fireworks particle tracking method for the efficient tracking of particles by considering maximum moving range and moving direction of particles, and shall show that the 3D speeds of particles can be obtained by finding the rotation angles of fireworks. Also, we carry out the performance evaluation of particle tracking: tracking speed and accuracy for tracking, classification, rotation angle respectively with respect to four types of fireworks: sphere, circle, chrysanthemum and heart.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.332-336
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• 2008

For reliable real-time interaction in a camera-tracked laser pointer system, a new idea is proposed and its feasibility is tested in this paper. In order to improve response time in the system and remove useless visual overload, the function of a laser pointer in the system is divided, the Region of Functional Interest is defined and subsequently its new interactions are introduced. Finally the experiments to measure reliability, accuracy, latency and usability are conducted and the results are presented.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.10 no.2
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• pp.37-44
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• 1992

Although scanners are much more expensive than other input devices expect for some low quality devices, raster scanner and vectorizing softwares have been used and will be used as a means for the data entry in GIS. In this study, the accuracy of raster data and vectorizing in data entry by scanning technology, the coverage generation are investigated. As a result, the deterioration of spatial resolution can be improved by using the histogram analysis and the line enhancement when we scan a map at a lower dpi. It is to be desired that a raster scanner dpi is selected 150 dpi or 200 dpi among five densities (75 dpi, 150, dpi, 200 dpi, 300 dpi, 400 dpi) in view of the storage of raster data and the RMSE of coverage generation. Also, it was very important role of the choice of trace parameters to trace raster data in the vectorizing procedure.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.105-108
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• 1989

This paper proposes a performance improvement to a control system with state feedback control loops and feedforward control loops proposed in a previous paper. The technique allows to solve the regulator problem and at the same time to make the system follow command signal. The scheme is implemented in a 16 bit microcomputer using a floating coprocessor. Tests on a DC machine have been conducted, comparisons with the previous results are made.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.218-232
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• 2022

Researches are underway to use a radar sensor, a sensor used for object recognition in vehicles, for position estimation. In particular, a method of classifying dynamic and static objects using the Doppler velocity, the output from the radar sensor, and calculating ego-motion using only static objects has been researched recently. Also, for the existing dynamic object classification, several methods using RANSAC or robust filtering has been proposed. Still, a classification method with higher performance is needed due to the nature of the position estimation, in which even a single failure causes large effects. Hence, in this paper, we propose a method to improve the classification performance compared to existing methods through tracking and filtering of dynamic objects. Additionally, the method used a GMPHD filter to maximize tracking performance. In effect, the method showed higher performance in terms of classification accuracy compared to existing methods, and especially shows that the failure of the RANSAC could be prevented.