The design of nonlinear optimal neurocontrollers based on the Adaptive Critic Designs (ACDs) family of algorithms has recently attracted interest. This paper presents a summary of these algorithms, and compares their ...
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The design of nonlinear optimal neurocontrollers based on the Adaptive Critic Designs (ACDs) family of algorithms has recently attracted interest. This paper presents a summary of these algorithms, and compares their performance when implemented on two different types of artificial neural networks, namely the multilayer perceptron neural network (MLPNN) and the radial basis function neural network (RBFNN). As an example for the application of the ACDs, the control of synchronous generator on an elec.ric power grid is considered and results are presented to compare the different ACD family members and their implementations on different neural network architectures.
In the present work, a constructive learning algorithm is employed to design an optimal one-hidden layer neural network structure that best approximates a given mapping. The method determines not only the optimal numb...
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In the present work, a constructive learning algorithm is employed to design an optimal one-hidden layer neural network structure that best approximates a given mapping. The method determines not only the optimal number of hidden neurons but also the best activation function for each node. Here, the projection pursuit technique is applied in association with the optimization of the solvability condition, giving rise to a more efficient and accurate computational learning algorithm. As each activation function of a hidden neuron is optimally defined for every approximation problem, better rates of convergence are achieved. The proposed constructive learning algorithm was successfully applied to identify a large-scale multivariate process, providing a multivariable model that was able to describe the complex process dynamics, even in long-range horizon predictions. The resulting identification model is then considered as part of a model-based predictive control strategy, with high-quality performance in closed-loop experiments.
The paper proposes a fast Fourier transform (FFT) architecture to satisfy both small area and high speed. The proposed architecture uses the mixed-radix algorithm based on the radix-4 and radix-2 algorithms and the me...
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The paper proposes a fast Fourier transform (FFT) architecture to satisfy both small area and high speed. The proposed architecture uses the mixed-radix algorithm based on the radix-4 and radix-2 algorithms and the memory bank structure for high speed real-time processing. To satisfy the small area requirement, it uses an in-place memory strategy that stores butterfly outputs in the same memory location used by butterfly inputs. To meet real-time processing, this paper proposes a continuous flow architecture using only two N-word memories for the mixed-radix algorithm. The proposed architecture can reduce the number of clock cycles about 70% compared with an existing architecture.
This paper reports on the design, fabrication, and testing of a novel analog MEMS varactor with measured tuning range of 300%. The proposed elec.rostatically actuated varactor is based on a parallel-plate approach and...
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This paper reports on the design, fabrication, and testing of a novel analog MEMS varactor with measured tuning range of 300%. The proposed elec.rostatically actuated varactor is based on a parallel-plate approach and Is best suited for microwave/millimeter-wave applications. The measured capacitance values are in the range of 40-160 fF and are achieved with DC voltages of 20-34 V. The proposed varactor has the additional advantages of very high resonant frequency (its series measured parasitic inductance is 9 pH) and high quality factor (higher than 80 at 40 GHz).
A novel technique for operating MOS translinear loops at very low supply voltages is presented. It is based on the use of a biasing cell recently reported and named "flipped voltage follower", that allows to...
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A novel technique for operating MOS translinear loops at very low supply voltages is presented. It is based on the use of a biasing cell recently reported and named "flipped voltage follower", that allows to create a very low impedance node in the translinear loops with a controllable and well-defined DC voltage even for large current swings, thus relaxing the supply voltage requirements for a given input current range. Measurement results of a 1.5V MOS translinear loop circuit implementing the square-root operator and fabricated in a 2.4μm CMOS process confirm the viability of the proposed approach.
Applications such as e-commerce payment protocols, elec.ronic contract signing, and certified e-mail delivery require that fair exchange be assured. A fair-exchange protocol allows two parties to exchange items in a f...
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ISBN:
(纸本)9781581137088
Applications such as e-commerce payment protocols, elec.ronic contract signing, and certified e-mail delivery require that fair exchange be assured. A fair-exchange protocol allows two parties to exchange items in a fair way so that either each party gets the other's item, or neither party does. We describe a novel method of constructing very efficient fair-exchange protocols by distributing the computation of RSA signatures. Specifically, we employ multisignatures based on the RSA-signature sch.me. To date, the vast majority of fair-exchange protocols require the use of zero-knowledge proofs, which is the most computationally intensive part of the exchange protocol. Using the intrinsic features of our multisignature model, we construct protocols that require no zero-knowledge proofs in the exchange protocol. Use of zero-knowledge proofs is needed only in the protocol setup phase - this is a one-time cost. Furthermore, our sch.me uses multisignatures that are compatible with the underlying standard (single-signer) signature sch.me, which makes it possible to readily integrate the fair-exchange feature with existing e-commerce systems.
We provide an iterative and a non-iterative channel impulse response (CIR) estimation algorithm for communication systems which utilize a periodically transmitted training sequence within a continuous stream of inform...
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We provide an iterative and a non-iterative channel impulse response (CIR) estimation algorithm for communication systems which utilize a periodically transmitted training sequence within a continuous stream of information symbols. The iterative procedure calculates the (semi-blind) Best Linear Unbiased Estimate (BLUE) of the CIR. The non-iterative version is an approximation to the BLUE CIR estimate, achieving almost similar performance, with much lower complexity. We first provide a formulation of the received data and correlation processing with the adjacent symbol correlation taken into account, and we then present the connections of the correlation based CIR estimation sch.me to the ordinary least squares CIR estimation, and the BLUE CIR estimation. Simulation results are provided to demonstrate the performance of the novel algorithms for 8-VSB ATSC Digital TV system.
An improved backflashover model, which estimates the lightning performance of high voltage overhead transmission lines using Monte Carlo statistical technique, is presented based upon a previous study. In contrast to ...
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An improved backflashover model, which estimates the lightning performance of high voltage overhead transmission lines using Monte Carlo statistical technique, is presented based upon a previous study. In contrast to the earlier approach in which only mean values of design characteristics and meteorological data were considered, this method takes into consideration the characteristics of each one individual tower of the transmission line and the exact meteorological conditions for the particular geographic region where each one tower is located. Furthermore it gives the opportunity to use in the calculations, either the measured footing resistance of each tower, or to estimate the tower footing resistance by providing the resistivity of soil and the geometric characteristics of the grounding system. The improved method coded as a Visual Basic computer program, has been applied, on several operating Hellenic transmission lines, with different geometrical and geographical characteristics, showing much greater accuracy than this which has been shown using the earlier approach and results almost identical to the field observation data. The proposed method can be used as a useful tool in the design of elec.ric power systems, aiding in a more effective protection of them against lightning strokes.
A fuzzy c-means based adaptive clustering algorithm is proposed for the fuzzy segmentation of 3D MR brain images, which are typically corrupted by noise and intensity non-uniformity (INU) artifact. The proposed algori...
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A fuzzy c-means based adaptive clustering algorithm is proposed for the fuzzy segmentation of 3D MR brain images, which are typically corrupted by noise and intensity non-uniformity (INU) artifact. The proposed algorithm enforces the spatial continuity constraint to account for the spatial correlations between image voxels, resulting in the suppression of noise and classification ambiguity. The INU artifact is compensated for by the introduction of a pseudo-3D bias field, which is modeled as a stack of smooth B-spline surfaces with continuity enforced across slices. The efficacy of the proposed algorithm is demonstrated experimentally using both simulated and real MR images.
In this paper we will develop a method to determine cross sections of arbitrary two-dimensional tubular structures, which are allowed to branch, by means of a Stokes flow based boundary integral formulation. The measu...
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In this paper we will develop a method to determine cross sections of arbitrary two-dimensional tubular structures, which are allowed to branch, by means of a Stokes flow based boundary integral formulation. The measure for the cross sections for a point on the boundary of a given structure will be the path obtained by integrating perpendicularly to the flow lines from one side of the boundary to the other. Special emphasis will be put on the behavior at branching points, the behavior at vortices, and the necessary boundary conditions. The method can be extended to three dimensional problems.
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