• Title/Summary/Keyword: orthonormal basis

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Face Recognitions Using Centroid Shift and Neural Network-based Principal Component Analysis (중심이동과 신경망 기반 주요성분분석을 이용한 얼굴인식)

  • Cho Yong-Hyun
    • The KIPS Transactions:PartB
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    • v.12B no.6 s.102
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    • pp.715-720
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    • 2005
  • This paper presents a hybrid recognition method of first moment of face image and principal component analysis(PCA). First moment is applied to reduce the dimension by shifting to the centroid of image, which is to exclude the needless backgrounds in the face recognitions. PCA is implemented by single layer neural network which has a teaming rule of Foldiak algorithm. It has been used as an alternative method for numerical PCA. PCA is to derive an orthonormal basis which directly leads to dimensionality reduction and possibly to feature extraction of face image. The proposed method has been applied to the problems for recognizing the 48 face images(12 Persons $\ast$ 4 scenes) of 64$\ast$64 pixels. The 3 distances such as city-block, Euclidean, negative angle are used as measures when match the probe images to the nearest gallery images. The experimental results show that the proposed method has a superior recognition performances(speed, rate). The negative angle has been relatively achieved more an accurate similarity than city-block or Euclidean.

The Active Noise Control in Harmonic Enclosed Sound Fields (I) Computer Simulation (조화가진된 밀폐계 음장에서의 능동소음제어 (I) 컴퓨터 시물레이션)

  • Oh, Jae-Eung;Lee, Tae-Yeon;Kim, Heung-Seob;Shin, Joon
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1054-1065
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    • 1993
  • A computer simulation is performed on the effectiveness of the active minimization of harmonically excited enclosed sound fields for producing global reduction in the amplitude of the pressure fluctuations. In this study for the appreciable reductions in total time averaged acoustic potential energy, $E_{pp}$, the transducer location strategies for three dimensional active noise control is presented based on a state space modal which approximates the closed acoustic field.In this study, the above theoretical basis is used to investigate the application of active control to sound fields of low modal density. By the used of room-like 3-dimensional rectangular enclosure it is demonstrated that the reductions in $E_{pp}$ can be achieved by using a single secondary source, provided that the source is placed within the half a wavelength from the primary source and placed away from nodal line of the sound field. Concerning the reductions in $E_{pp}$ by minimzing the pressure in sound fields by the use of 3-dimensional rectangular enclosure, the effects of the number of sensors and the locations of these sensors are investigated. When a few modes dominate the response it is found that if only a limited number of sensors are located away from nodal line and located at the pressure maxima of the sound field such as at each corner of a rectangular enclosure.