Correctly recognizing characters with peculiarities for each writer is a difficult problem. The process of absorbing variations in individual writing by creating an individual dictionary is also difficult when a write...
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In this paper a novel approach to the problem of edge preserving smoothing, which allows to break an image into a set of homogeneous regions, is proposed and evaluated. The new algorithm is based on the combined forwa...
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A new filtering approach designed to eliminate impulsive noise in color images, while preserving Jine image details is presented. The computational complexity of the new filter is significantly lower than that of the ...
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The use of low-level visual features to search and retrieve information in the multimedia databases has drawn much attention in the recent years [1,2]. Many of the existing techniques of image retrieval are based on i...
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A new filtering approach designed to eliminate impulsive noise in color images, while preserving fine image details is presented in this paper. The comparison shows that the new filter outperforms the VMF, as well as ...
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Based on Moore and Greitzer's model (1986), surge behavior is found to be attributable to the appearance of Hopf bifurcation. Lyapunov function based control is proposed to provide the asymptotic stability of the ...
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Based on Moore and Greitzer's model (1986), surge behavior is found to be attributable to the appearance of Hopf bifurcation. Lyapunov function based control is proposed to provide the asymptotic stability of the post-surge operating point for the compressor with uncertain axisymmetric characteristics. Although robust stabilization can be achieved by Lyapunov function based design, such an approach strongly relies on the explicit knowledge of the operating point. A washout filter type linear controller is proposed to delay and suppress the occurrence of Hopf bifurcation in compressor dynamics, which does not require the knowledge of system equilibria. Numerical results demonstrate the effectiveness of the proposed designs.
In this paper discrete-time iterative learning control (ILC) systems are analysed from an algebraic point of view. The algebraic analysis shows that an ILC synthesis problem can be considered as a tracking problem of ...
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In this paper discrete-time iterative learning control (ILC) systems are analysed from an algebraic point of view. The algebraic analysis shows that an ILC synthesis problem can be considered as a tracking problem of a multi-channel step-function. Furthermore, the plant to be controlled is a static multivariable plant. Another major contribution of this paper is a general convergence theory of ILC systems in terms of their closed-loop poles. This convergence theory shows that time-variant ILC control laws should be typically used instead of time-invariant control laws in order to guarantee good transient tracking behaviour. Simulations high-light the different theoretical findings in this paper.
To estimate the amount of fatigue damage in metallic plates such as steel and stainless steel, we have investigated the relationship between the amount of plane bending fatigue damage and residual magnetization. The m...
To estimate the amount of fatigue damage in metallic plates such as steel and stainless steel, we have investigated the relationship between the amount of plane bending fatigue damage and residual magnetization. The magnetic flux density in the Z component (Bz) at 1 mm above a specimen caused by residual magnetization is measured by using a thin-film flux-gate magnetic sensor. From the results of our experiment, the magnetic flux density has clear dependence on the increase of bending stress and the number of stress cycles in austenitic stainless steel. The distribution of Bz on steel plates is changed by the amount of plane bending fatigue damage. But, the relationship between the change of Bz and the number of stress cycles is not clear in the case of steel plates. In this paper, the relationship between the amount of plane bending fatigue damage and residual magnetization in metallic plates is discussed.
The paper investigates the closed-loop stability issue of finite-precision realizations for digital controllers implemented in floating-point arithmetic. Unlike the existing methods which only address the effect of th...
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ISBN:
(纸本)0780375165
The paper investigates the closed-loop stability issue of finite-precision realizations for digital controllers implemented in floating-point arithmetic. Unlike the existing methods which only address the effect of the mantissa bits in floating-point format to the sensitivity of closed-loop stability, the sensitivity of closed-loop stability is analyzed with respect to both the mantissa and exponent bits of floating-point format. A computationally tractable finite word length (FWL) closed-loop stability measure is defined, and the optimal controller realization problem is posed as searching for a floating-point realization that maximizes the proposed measure. A numerical optimization approach is adopted to solve for the resulting optimization problem. Simulation results show that the proposed design procedure yields computationally efficient controller realizations with enhanced FWL closed-loop stability performance.
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