• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.556-558
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• 2002

항공사진에 포함된 기점 마크의 방사 및 기하 특성을 이용하여 마크의 중심 위치를 자동으로 인식하기 위한 방안을 제안한다. 마크를 포함하는 배경 영역의 방사 특성에 기반을 푼 전략에 근거하여 입력된 영상을 이치화한 다음 형태 연산자를 적용시켜 기전 마크가 있는 후보 영역을 추출한다. 기하 특성에 기반을 둔 전략에 근거하여 ▽$^2$G 필터링과 대칭성 강조 필터링을 적용시킨 후, 대칭이 가장 강하게 나타나는 위치인 마크의 중심 위치를 구한다. 66매의 기점 마크 영상에 대한 평가 결과 중심 위치가 1 화소의 정확도까지 얻어질 수 있다는 것을 확인할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.606-609
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• 2021

최근 한국에서도 이루다의 윤리 이슈를 기점으로 딥러닝 모델의 윤리적 언어학습 필요성이 대두되었다. 그럼에도 불구하고 영어 데이터에 비해 한국어 데이터는 Korean Hate Speech Detection Dataset 이 유일하다. 이번 연구에서는 기존 데이터 세트의 유연성이 떨어지고 세부 라벨이 제한적이라는 문제를 개선한 새로운 데이터 세트를 제안하고, 해당 데이터 세트에 대하여 다양한 신경망 분류 모델을 적용한 벤치마크 결과를 공개한다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.88-95
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• 2003

This paper presents the measurement and correction method of PCB alignment errors for PCB screen printer. Electronic equipment is getting smaller and yet must satisfy high performance standard. Therefore, there is a great demand for PCB with high density. However conventional PCB screen printer doesn't have enough accuracy to accommodate the demand fur high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because the alignment errors of PCB occur when it is loaded to the screen printer. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors with high-accuracy. An automatic optical inspection part measures the PCB alignment errors using machine vision, and the high-accuracy 3-axis stage makes correction for these errors. This system used two CCD cameras to get images of two fiducial marks of PCB. The geometrical relationship between PCB, cameras, and xy$\theta$ stage is derived, and analytical equations for alignment errors are also obtained. The unknown parameters including camera declining angles and etc. can be obtained by initialization process. Finally, the proposed algorithm is verified by experiments by using test bench.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.96-104
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• 2003

This paper presents the measurement and correction method of PCB alignment errors for PCB screen printer. Electronic equipment is getting smaller and yet must satisfy high performance standard. Therefore, there is a great demand for PCB with high density. However conventional PCB screen printer doesn't have enough accuracy to accommodate the demand for high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because the alignment errors of PCB occur when it is loaded to the screen printer. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors with high-accuracy. An automatic optical inspection part measures the PCB alignment errors using machine vision, and the high-accuracy 3-axis stage makes correction for these errors. This system used two CCD cameras to get images of two fiducial marks of PCB. The centers of fiducial marks are obtained by using moment, gradient method. The first method is calculating the centroid by using first moment of blob, and the latter method is calculating the center of the circle whose equation is obtained by curve-fitting the boundaries of fiducial mark. The operating system used to implement the whole set-up is carried in Window 98 (or NT) environment. Finally we implemented this system to PCB screen printer.