• Title/Summary/Keyword: 왜곡률

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A Study on the Problems and Principles of the School Library Opening Policy (학교도서관 지역사회 개방의 문제와 발전적 원리)

  • Kim, Jong-Sung
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.21 no.4
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    • pp.17-31
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    • 2010
  • The purpose of this study is to make an inspection of the School Library Opening Policy. Some problems show the policy is not only ineffective but also disadvantage to the development of school libraries. The writer suggested three principles and critical strategies for the successful implementation of the School Library Opening Policy.

Interpretation of Influence Winding Short Phase of Induction Motor to Distortion Ratio of Park's Vector Pattern (유도전동기의 권선 단락 상에 따른 팍스 벡터 패턴 왜곡률의 영향 해석)

  • Yang, Chul-Oh;Kim, Jong-Sun;Kim, Jun-Young;Park, Kyu-Nam;Song, Myung-Hyun
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2075-2076
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    • 2011
  • The stator winding faults diagnosis technique based on MCSA is as follows. Firstly, collecting the 3 phase motor currents, that signal is transformed by (d-q transform, $i_d$, $i_q$). Park's vector pattern, the circle that is down by d-q transformed currents($i_d$, $i_q$). The circle is widely used for stator winding faults detection. The current distortion ratio(DR), defined by the ratio of max-axis and min-axis of ellipse of Park's vector's pattern. In this study, distortion ratio of Park's vector pattern is suggested for Auto diagnosis of stator winding short fault and usefulness of distortion ratio is verified through simulation using LabVIEW program.

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Study on Distortion Ratio Calculation of Park's Vector Pattern for Diagnosis of Stator Winding Fault of Induction Motor (유도전동기의 고정자 권선고장 진단을 위한 팍스벡터 패턴의 왜곡률 연산에 대한 연구)

  • Yang, Chul-Oh;Park, Kyu-Nam;Song, Myung-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.4
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    • pp.643-649
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    • 2012
  • The diagnosis technique of stator winding faults based on Motor Current Signature Analysis(MCSA) was suggested. Park's vector pattern, the circle that is drawn by d-q transformed currents($i_d$, $i_q$), is widely used for stator winding faults detection. The current Distortion Ratio(DR), defined by the ratio of max axis and min axis of ellipse of Park's vector's pattern, was more simple and powerful method than the Park's vector pattern. In this study, a calculation method of distortion ratio of Park's vector pattern was suggested for auto diagnosis of stator winding short fault and usefulness of suggested calculation method of distortion ratio was verified through simulation using LabVIEW program.

Adaptive Regularized Enhancement of Wavelet Compressed Video (웨이블릿 압축 동영상의 정칙화 기반 적응적 개선에 관한 연구)

  • 정정훈;기현종;이성원;백준기
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.4
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    • pp.39-44
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    • 2004
  • The three-dimensional (3D) wavelet transform with motion compensation is suitable for very high quality video coding due to both spatial and temporal decorrelations. However, it still suffers from image degradation such as ringing artifact and afterimage because of the loss of high frequency components by quantization. This paper proposes an iterative regularized enhancement of the motion-compensated 3D wavelet coded video. We also propose the adaptive implementation of the constraints for the regularization. It selectively suppresses the high frequency component along only the corresponding edge direction.

Key Frame Extraction using Shot Coverage and Distortion (샷 기여도와 왜곡률을 고려한 키 프레임 추출 알고리즘)

  • 이중용;문영식
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.3
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    • pp.137-143
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    • 2003
  • Key frame extraction has been recognized as one of tile important research issues in video information retrieval. Although progress has been made in key frame extraction, the existing approaches do not evaluate the importance of extracted frame Quantitatively, and Dey are computationally expensive or ineffective. In this Paper, we introduce a new 미해rithm for key frame extraction using shot coverage and distortion. The algorithm finds significant key frames from candidate key frames. When selecting the candidate frames, the coverage rate to the total frames from each frame is computed by using the difference between the adjacent frames in tile shot. The frames within 10$\%$ from the top are selected as the candidates. Then, by comfuting the distortion rate of the candidates against all frames, pick the frames which arc most representative are selected. The performance of the proposed algorithm has been verified by a statistical test. Experiments show that more than 13-50$\%$ improvement has been obtained by the proposed algorithm compared to the existing methods.

Study on Noise Filling algorithm of Unified Speech and Audio Coding (통합 음성/오디오 부호화기의 Noise Filling 알고리즘에 대한 연구)

  • Song, Jeongook;Kang, Hong-Goo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.07a
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    • pp.260-261
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    • 2012
  • 본 논문에서는 Unified Speech and Audio Coding (USAC)에 적용된 Noise Filling의 부호화 과정에서 음질 왜곡 정도에 따라 Noise level을 설정하는 방법을 제안한다. USAC는 Moving Picture Experts Group (MPEG)에서 표준화한 최신의 음성/오디오 통합 코덱으로 현존하는 코덱 중에 최고의 성능을 가지고 있다. 하지만, 복호화기 기술만 표준화하여, 인코더를 설계하는 방법에 따라 음질의 차이가 존재한다 현재 오픈 소스 기반으로 진행되고 있는 프로젝트 JAME에서는 이러한 음질 차이를 극복하고, USAC에 적용된 핵섬 인코더 기술의 성능을 최대화 할 수 있는 여러 가지 방법을 포함하고 있다. 그 중 Noise Filling은 저 전송률 부호화 과정에서 양자화 되지 않는 스펙트럼에 대하여 일정한 noise level을 넣어 인지적으로 음질을 향상시키는 방법이다. 제안된 Noise Filling 부호화 방법은 현재 프레임의 음질 왜곡 정도를 반영하여, noise-like 신호 성분을 더욱 정교하게 부호화 할 수 있게 하였다.

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Auto-Diagnosis for Stator Winding Faults Using Distortion Ratio of Park's Vector Pattern (Park's 벡터 패턴의 왜곡률을 이용한 고정자 권선 고장 자동진단)

  • Song, Myung-Hyun;Park, Kyu-Nam;Han, Dong-Gi;Yang, Chul-Oh
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.2
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    • pp.160-163
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    • 2008
  • In this paper, an auto-diagnosis method of the stator winding fault for small induction motor is suggested. 3-phase stator currents are sampled, filtered, and transformed with Park's vector transformation. After then Park's vector patterns are obtained. To detect the stator winding fault automatically, a distortion ratio is newly defined and compared with the one of healthy motor, and the threshold levels of distortion ratio are suggested. The 2-turn, 4-turn, 8-turn winding fault are tested with no load, 25%, 50%, 75%, and 100% rated load. The distortion ratio of the Park's vector patterns are increased as the increase of the faulted turns, but are same as the increase of the load.

Main Points Extraction and Layout Vectorization of Hand-designed Forms (손으로 설계한 서식 문서의 주요점 검출 및 서식 구조 벡터화)

  • Kim, Byeong-Yong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2001.10a
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    • pp.519-522
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    • 2001
  • 본 논문은 손으로 자유롭게 그린 서식 문서의 주요점을 검출하여 서식의 구조를 벡터화하는 방법을 제안한다. 선 성분의 주요점을 검출하여 그 구조를 벡터화하는 방법은 주로 인쇄 서식 문서의 구조 분석에 적용하기 좋은 방법이다. 이에 반해 손으로 설계한 서식 문서는 주요점 부분이 왜곡되어 있기 때문에 주요점의 검출이 손쉽게 이루어지기 곤란하다. 이 논문에서는 이러한 문제를 해결하기 위해 손으로 설계한 서식 문서를 세선화한 다음 여유 성분을 갖는 마스크를 적용하고 후처리를 통해 주요점 부분의 심한 왜곡을 보상하는 방법을 제안하여 손으로 설계한 서식 문서에서도 주요점의 검출이 가능하도록 하였다. 제안한 방법의 유효성을 확인하기 위한 실험 결과 손으로 설계한 서식의 경우 91.9%, 인쇄 서식의 경우 100%의 벡터화 성공률을 보여주어 제안한 방법이 손으로 설계한 서식 구조의 벡터화에 유효함을 확인하였다.

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Automatic Diagnosis for Stator Winding Faults Using Distortion Ratio (왜곡률을 이용한 고정자 권선고장 자동진단)

  • Song, Myung-Hyun;Park, Kyu-Nam;Han, Dong-Gi;Yang, Chul-Oh
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.358-360
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    • 2007
  • In this paper, an auto-diagnosis method of the stator winding fault for small induction motor is suggested. 3-phase stator currents are sampled, filtered, and transformed with Park's vector transformation. After then Park's vector patterns are obtained. To detect the stator winding fault automatically, a distortion ratio (id/iq) is newly defined and compared with the one of healthy motor, and the threshold levels are suggested. The 2-turn, 4-turn, 8-turn winding fault are tested with no load, 25%, 50%, 75%, and 100% rated load. The distortion ratio of the Park's vector patterns are increased as the increase of the faulted turns, but are same as the increase of the load.

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