A novel scheme to identify flow regime and measure quality in gas-liquid two-phase using differential pressure signal is proposed. Flow regime is identified based on wavelet analysis and back-propagation (BP) neural n...
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A novel scheme to identify flow regime and measure quality in gas-liquid two-phase using differential pressure signal is proposed. Flow regime is identified based on wavelet analysis and back-propagation (BP) neural network. Nine-scale Haar wavelet decomposition is performed on differential pressure signal. The scale energy ratio is extracted as the input of BP network to identify flow regime. Based on the flow regime information, relation between quality and pressure signal is fitted by polynomial. Experiments show that in annular flow, the polynomial fits well.
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.
The paper analyzes global solutions to the optimal digital controller realization problem based on maximizing a finite word length (FWL) closed-loop stability measure. For each closed-loop eigenvalue, a single-pole FW...
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ISBN:
(纸本)0780375165
The paper analyzes global solutions to the optimal digital controller realization problem based on maximizing a finite word length (FWL) closed-loop stability measure. For each closed-loop eigenvalue, a single-pole FWL stability function is first introduced, and a single-pole FWL stability measure is then defined as the maximum of the corresponding single-pole stability function over all the controller realizations. It is shown that the minimum of the single-pole stability measures for all the closed-loop eigenvalues is an upper bound of the optimal value for the optimal realization problem. An analytical method to compute a single-pole stability measure is developed, and an expression for all the realizations which achieve a given single-pole measure is derived. When a realization, which is a solution of the minimum single-pole measure, further satisfies the condition that the values of all its single-pole stability functions are not less than the minimum single-pole measure, the minimum single-pole measure is the optimal value of the optimal realization problem and this realization is the solution for the optimal realization problem. A computationally simple algorithm is presented.
A novel method for the on-line measurement of powder flowrate in pneumatic conveying system is proposed. It is a nonrestrictive method based on the measurement values of total pressure drop of gas-solid two-phase flow...
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ISBN:
(纸本)0780366468
A novel method for the on-line measurement of powder flowrate in pneumatic conveying system is proposed. It is a nonrestrictive method based on the measurement values of total pressure drop of gas-solid two-phase flow and the powder concentration, and also has the advantage of simplicity, reliability and low cost. An intelligent measurement system for the powder flowrate measurement is developed. The experimental results show that the maximum measurement error is satisfactory for industrial application.
Based on electrical capacitance tomography technique, a new method for the void fraction measurement of two-phase flow is proposed. A void function measurement system is established, A mathematical model of image reco...
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ISBN:
(纸本)0780366468
Based on electrical capacitance tomography technique, a new method for the void fraction measurement of two-phase flow is proposed. A void function measurement system is established, A mathematical model of image reconstruction of electrical capacitance tomography is developed. To obtain the quantitative information of two-phase flow, a new image reconstruction algorithm is presented. The experimental results show that the accuracy of void fraction measurement is satisfactory. The proposed method is suitable for the void fraction measurement of many kinds of two-phase flow.
A two-stage electroencephalogram (EEG) source tomography method is proposed. First, the layer recursive algorithm (LRA) is developed to calculate the cortical potentials from the scalp potentials by using the finite v...
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