• Title/Summary/Keyword: centroid

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Obtaining the driving scale of turbulence from observations

  • Cho, Jungyeon
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.56.2-56.2
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    • 2017
  • To maintain turbulence in astrophysical fluids, driving is required. Constraining the driving scale of turbulence is important to identify the driving mechanism and also to obtain more accurate turbulence statistics from observations. We discuss how to obtain the driving scale of turbulence from observations. First, we explain the method to obtain the driving scale from the standard deviation of centroid velocity (i.e. the first moment of the line profile). Second, we discuss other techniques to obtain the driving scale.

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The Analytical Study of Axial Force-Moment Relationships for High Strength Concrete Structures using Reliability Theory (신뢰성이론을 이용한 고강도콘크리트 구조물의 축력-모멘트관계에 관한 해석적인 연구)

  • 최광진;홍원기;장일영;송재호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.500-506
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    • 1997
  • The main object of the study is that axial force-moment relationships for high strength concrete structures using reliability theory probability conception. And mean stress factors and centroid factors proposed to high strength concrete structures using reliability theory. Finally, the established experimental data for axial force-moment relationships are compared to the analytical data for the axial force-moment relationships in this analytical method.

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Analysis of Document Clustering Varing Cluster Centroid Decisions (클러스터 중심 결정 방법에 따른 문서 클러스터링 성능 분석)

  • 오형진;변동률;이신원;박순철;정성종;안동언
    • Proceedings of the IEEK Conference
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    • 2002.06c
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    • pp.99-102
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    • 2002
  • K-means clustering algorithm is a very popular clustering technique, which is used in the field of information retrieval. In this paper, We deal with the problem of K-means Algorithm from the view of creating the centroids and suggest a method reflecting document feature and considering the context of each document to determine the new centroids during the process of forming new centroids. For experiment, We used the automatic document summarizer to summarize the Reuter21578 newslire test dataset and achieved 20% improved results to the recall metrics.

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Fiducial Mark Recognition Using Generalized Hough Transform (Generalized Hough Transform을 이용한 Fiducial Mark 인식)

  • 조태훈
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.04b
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    • pp.568-570
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    • 2001
  • fiducial mark는 PCB 정밀조립/검사 장비에서 위치보정을 위해 필수적으로 사용되는데, 실제 생산현장에서의 fiducial mark의 품질은 완전하지 않고, 손상된 상태인 경우가 많이 발생한다. 기존에 주로 사용되는 blob centroid 방법에 의한 mark의 위치추출은 mark의 상태가 손상되었을 경우, 큰 오차를 수반하게 된다. 본 논문에서는 Generalized Hough Transform을 이용한 fiducial mark의 중심위치 기법을 개발하여, 적용한 결과 손상된 mark에 대해서도 매우 강건한 결과를 보여주었다.

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A study on the new gamut mapping method for digital soft color proofing (디지털 소프트 칼라 교정인쇄를 위한 새로운 색역 사상방법에 관한 연구)

  • 송경철;강상훈
    • Proceedings of the Korean Printing Society Conference
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    • 2002.05a
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    • pp.10-18
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    • 2002
  • On the process of cross-media color reproduction, a key feature is the use of gamut mapping techniques to adjust the different color gamuts between displays and printers. Even though a number of GMAs have been published, but there are no method satisfactory enough for more exect color reproduction. In this paper, the gamut mapping methods of nearest point clipping(NPC), centroid clipping (SLIN), straight clipping and cusp clipping(CUSP) were tested and analyzed with color difference, and a new gamut mapping algorithm based on variable anchor point method was proposed.

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The Enhancement of Learning Time in Fuzzy c-means algorithm (학습시간을 개선한 Fuzzy c-means 알고리즘)

  • 김형철;조제황
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.113-116
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    • 2001
  • The conventional K-means algorithm is widely used in vector quantizer design and clustering analysis. Recently modified K-means algorithm has been proposed where the codevector updating step is as fallows: new codevector = current codevector + scale factor (new centroid - current codevector). This algorithm uses a fixed value for the scale factor. In this paper, we propose a new algorithm for the enhancement of learning time in fuzzy c-means a1gorithm. Experimental results show that the proposed method produces codebooks about 5 to 6 times faster than the conventional K-means algorithm with almost the same Performance.

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Rate Control of Very Low Bit-rate Video Coder Using Fuzzy Quantization (퍼지 양자화에 의한 초저전송율 동영상 부호기의 율 제어)

  • 양근호
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2000.08a
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    • pp.189-192
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    • 2000
  • A fuzzy controller for the evaluation of the quantization parameters in the H.263 coder has been introduced. We adopted a Mamdani fuzzy controller with centroid defuzzification. The inputs are variance, entropy, current motion vector and previous motion vector. This results is obtained a effective rate control technique using fuzzy Quantization.

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C-V Characteristics in Nanometer Scale MuGFETs with Considering Quantum Effects (양자 현상을 고려한 나노미터 스케일 MUGFETS의 C-V 특성)

  • Yun, Se-Re-Na;Yu, Chong-Gun;Park, Jong-Tae
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.11
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    • pp.1-7
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    • 2008
  • In this work, a two dimensional, self-consistent Poisson-$Schr{\ddot{o}}dinger$ solver has been implemented to study C-V characteristics in nanometer scale MuGFETs with considering quantum effects. The quantum-mechanical effects on gate-channel capacitance for different device dimension and gate configurations of nanometer scale MuGFETs have been analyzed. It has been found that 4he gate-channel capacitance per unit gate area is increased as the device dimension decreases. For different gate configurations, the gate-channel capacitance is decreased with increase of effective gate number. Those resu1ts have been explained by the distribution profile of electron concentration in the silicon surface and inversion capacitance. The length of inversion-layer centroid has been calculated from inversion capacitance with device dimension and gate configurations.

Kinematic Analysis of Samdan Didimsae Movement for Jajinmori Jangdan (자진모리장단에 따른 한국무용3단 디딤새 동작에 관한 운동학적 분석)

  • Ahn, Wan-Sik
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.203-212
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    • 2008
  • The purpose of this study is to propose appropriate model for 3 staged Didimsae movement to Jajinmori rhythm and to provide information for ideal foot step movements. For the locational change of body center, the height of body center is lowered at the moment of forward step and during forward intersection of the feet, forward direction linear motion is converted to vertical motion to maintain stability. Speed change of body center reduces flow of body on step forward moment and controls rapid forward movement for stabled movement and position when preventing fast forward horizontal direction movement of centroid speed while knee joint and foot joint are vertically risen for heel bone contacts the ground. For angle changes of joints, in order to prevent hyperextension of lower leg, hip joint is extended and knee joint is curved to secure stability of movement for smooth curves and extension. When centroid of foot joint is moved from top of the feet to whole foot sole and when left foot makes dorsal curve, stabled movement is accomplished.