Galerkin Projection Methods for Solving Multiple Linear Systems

In this paper, we consider using conjugate gradient (CG) methods for solving multiple linear systems A(i) x(i) = b(i) , for 1 ≤ i ≤ s, where the coefficient matrices A(i) and the right-hand sides b( i) are different in general. In particular, we focus on the seed projection method which generates a Krylov subspace from a set of direction vectors obtained by solving one of the systems, called the seed system, by the CG method and then projects the residuals of other systems onto the generated Krylov subspace to get the approximate solutions. The whole process is repeated until all the systems are solved. Most papers in the literature [T. F. Chan and W. L. Wan, SIAM J. Sci. Comput., 18 (1997), pp. 1698­1721; B. Parlett Linear Algebra Appl., 29 (1980), pp. 323­346; Y. Saad, Math. Comp., 48 (1987), pp. 651­662; V. Simoncini and E. Gallopoulos, SIAM J. Sci. Comput., 16 (1995), pp. 917­933; C. Smith, A. Peterson, and R. Mittra, IEEE Trans. Antennas and Propagation, 37 (1989), pp. 1490­1493] considered only the case where the coefficient matrices A( i) are the same but the right-hand sides are different. We extend and analyze the method to solve multiple linear systems with varying coefficient matrices and right-hand sides. A theoretical error bound is given for the approximation obtained from a projection process onto a Krylov subspace generated from solving a previous linear system. Finally, numerical results for multiple linear systems arising from image restorations and recursive least squares computations are reported to illustrate the effectiveness of the method.published_or_final_versio

Wavelet analysis of head-related transfer functions

The directional-dependent information in the head-related transfer function (HRTF) is important for the study of human sound localization system and the synthesis of virtual auditory signals. Its time-domain and frequency-domain characteristics have been widely studied by researchers. The purpose of this paper is to explore the ability of discrete wavelet transform to describe the time-scale characteristics of HRTFs. Both the time-domain characteristics and energy distribution of different frequency subbands were studied. Discrete wavelet analysis is found to be a new direction-dependence information showing the relation of the characteristics of the HRTFs to sound source directions.published_or_final_versio

A comparative study of Kalman filtering for sensorless control of a permanent-magnet synchronous motor drive

Author name used in this publication: Borsje, P.Author name used in this publication: Wong, Y. K.Author name used in this publication: Ho, S. L.Refereed conference paper2004-2005 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Speed estimation of an induction motor drive using an optimized extended Kalman filter

Author name used in this publication: K. L. ShiAuthor name used in this publication: Y. K. WongAuthor name used in this publication: S. L. Ho2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A simulation study on sensorless control of permanent magnet synchronous motor drives

Author name used in this publication: Tze-Fun ChanRefereed conference paper2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Randomized trial of use of incentive to increase the response rate to a mailed survey

Author name used in this publication: Tong M. F. ChanAuthor name used in this publication: Sonny H. M. TseAuthor name used in this publication: Mary C. DayAuthor name used in this publication: Edmond T. F. TongAuthor name used in this publication: Lorna K. P. Suen2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A rule-based acceleration control scheme for an induction motor

Author name used in this publication: Y. K. WongAuthor name used in this publication: S. L. Ho2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Fast and easy blind deblurring using an inverse filter and PROBE

PROBE (Progressive Removal of Blur Residual) is a recursive framework for blind deblurring. Using the elementary modified inverse filter at its core, PROBE's experimental performance meets or exceeds the state of the art, both visually and quantitatively. Remarkably, PROBE lends itself to analysis that reveals its convergence properties. PROBE is motivated by recent ideas on progressive blind deblurring, but breaks away from previous research by its simplicity, speed, performance and potential for analysis. PROBE is neither a functional minimization approach, nor an open-loop sequential method (blur kernel estimation followed by non-blind deblurring). PROBE is a feedback scheme, deriving its unique strength from the closed-loop architecture rather than from the accuracy of its algorithmic components

Neural network model of binaural hearing based on spatial feature extraction of the head related transfer function

In spatial hearing, complex valued head-related transfer function (HRTF) can be represented as a real valued head-related impulse response (HRIR). Using Karhunen-Loeve expansion, the spatial features of the normalized HRIRs on measurement space can be extracted as spatial character functions. A neural network model based on Von-Mises function is used to approximate the discrete spatial character function of HRIR. As a result, a time-domain binaural model is established and it fits the measured HRIRs well.published_or_final_versio

Direct self control of induction motor based on neural network

Author name used in this publication: Y. K. WongAuthor name used in this publication: S. L. Ho2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe