Keller's theorem relates the components of the macroscopic dielectric response of a binary two-dimensional composite system with those of the reciprocal system obtained by interchanging its components. We present ...
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Keller's theorem relates the components of the macroscopic dielectric response of a binary two-dimensional composite system with those of the reciprocal system obtained by interchanging its components. We present a derivation of the theorem that, unlike previous ones, does not employ the common assumption that the response function relates an irrotational to a solenoidal field and that is valid for dispersive and dissipative anisotropic systems. We show that the usual statement of Keller's theorem in terms of the conductivity is strictly valid only at zero frequency and we obtain a new generalization for finite frequencies. We develop applications of the theorem to the study of the optical properties of systems such as superlattices, 2D isotropic and anisotropic metamaterials and random media, to test the accuracy of theories and computational schemes, and to increase the accuracy of approximate calculations.
A scattering (S-) parameter method has been proposed for electromagnetic property extraction of a target layer within metal-backed inhomogeneous metamaterial (MM) structures. It relies on recursive S-parameters for tw...
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A scattering (S-) parameter method has been proposed for electromagnetic property extraction of a target layer within metal-backed inhomogeneous metamaterial (MM) structures. It relies on recursive S-parameters for two different polarizations (parallel and perpendicular). Two different algorithms depending on the value of the incidence angles were proposed to add flexibility to our method. The algorithms were first validated by a metal-backed quasi-one-port method applicable only for one-layer (homogeneous) samples. Then, they were applied to extract electromagnetic properties of the split-ring-resonator-wire MM slab of a metal-backed two-layer inhomogeneous structure and the Omega MM slab of a metal-backed four-layer inhomogeneous structure, and extracted properties by our algorithms were compared with those retrieved by different methods applicable for homogeneous samples only. The accuracy of our method was also examined when there was some noise in S-parameters, when there was a misalignment in incidence angles, and a when large value of iteration number was used.
This work studies the fault estimation problem for a class of nonlinear systems subjected to missing measurements and random component faults under the Round-Robin protocol. Considering that the communication bandwidt...
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This work studies the fault estimation problem for a class of nonlinear systems subjected to missing measurements and random component faults under the Round-Robin protocol. Considering that the communication bandwidth is not infinite in the actual projects, the Round-Robin protocol is used for data scheduling, in which sensor nodes cyclically transmit data to the controller/filter. Meanwhile, component faults are also considered which usually caused by actuator faults. It should be emphasized that the introduction of RR protocol will make the system output equation more complex, the MMs and component faults will generate more unknown parameters, which will bring new challenges during the design of the filter. In respect of the problems above, a recursive joint state and fault estimation (JSFE) algorithm is proposed to solve the difficulties caused by missing measurements, component faults, and nonlinearity. The performance of the designed JSFE filter is analyzed by using the boundedness theorem and the reasonable parameter condition is derived for this filter. Finally, an engineering example is given to verify the effectiveness and feasibility of the proposed joint state and fault estimation scheme. This study provides a new theoretical basis and reference for the JSFE of nonlinear systems with mixed faults under RR protocol.
The optimal control problem of singularly perturbed bilinear system is studied. A recursive algorithm is presented to solve the corresponding nonlinear algebraic equations. 'rhe algorithm removes the ill-condition...
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The optimal control problem of singularly perturbed bilinear system is studied. A recursive algorithm is presented to solve the corresponding nonlinear algebraic equations. 'rhe algorithm removes the ill-conditioning by decomposing the higher order equation into lower order equations and develops a technique which enables us to obtain an arbitrary accuracy that is, O(epsilon(k)) approximation for this problem. A numerical example is presented to support the theoretical results.
This paper discusses an algorithm to compute the Markov parameters of an observer or Kalman filter from experimental input and output data. The Markov parameters can then be used for identification of a state-space re...
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This paper discusses an algorithm to compute the Markov parameters of an observer or Kalman filter from experimental input and output data. The Markov parameters can then be used for identification of a state-space representation, with associated Kalman or observer gain, for the purpose of controller design. The algorithm is a nonrecursive matrix version of two recursive algorithms developed in previous works for different purposes, and the relationship between these other algorithms is developed. The new matrix formulation here gives insight into the existence and uniqueness of solutions of certain equations and offers bounds on the proper choice of observer order. It is shown that if one uses data containing noise and seeks the fastest possible deterministic observer, the deadbeat observer, one instead obtains the Kalman filter, which is the fastest possible observer in the stochastic environment. The results of the paper are demonstrated in numerical studies and experiments on the Hubble space telescope.
For a system described by the triple (A9B9C) where the matrix A has a set of distinct eigenvalues and a wellconditionedmodal matrix, we propose measures of modal controllability and observability. The angles between t...
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This paper presents a new basis, the WSB basis, which unifies the Bemstein basis, Wang-Ball basis and Said-Ball basis, and therefore the Bézier curve, Wang-Ball curve and Said-Ball curve are the special cases of ...
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This paper presents a new basis, the WSB basis, which unifies the Bemstein basis, Wang-Ball basis and Said-Ball basis, and therefore the Bézier curve, Wang-Ball curve and Said-Ball curve are the special cases of the WSB curve based on the WSB basis In addition, the relative degree elevation formula, recursive algorithm and conversion formula between the WSB basis and the Bern- stein basis are given.
The existing method for blind identification of a punctured convolutional code involves searching for dual words and the puncturing pattern exhaustively. As the length of the dual words and the code rate increase, the...
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The existing method for blind identification of a punctured convolutional code involves searching for dual words and the puncturing pattern exhaustively. As the length of the dual words and the code rate increase, the computational complexity of this method expands exponentially. To address this problem, a fast scheme for blind identification of punctured convolutional codes is proposed. First, a recursive algorithm for solving the parity check equation set is proposed. The dual word and generator polynomial bases of the punctured convolutional code are estimated by using the recursive algorithm. After this, by using the structural properties of the generator matrix of the blocked code, possible generator matrices of the punctured convolutional code are obtained. Finally, since a generator polynomial of the parent convolutional code can be recovered from any column of its polycyclic pseudocirculant matrix, the corresponding generator matrix of the parent code and the puncturing pattern are reconstructed simultaneously from an estimation of the generator matrix of the punctured code. The reconstructed generator matrix of the parent code with a minimal constraint length is determined to be the identification result. Simulation experiments show the effectiveness of the proposed method. As there is no need to search for the dual word and puncturing pattern exhaustively, the method can achieve fast identification of punctured convolutional codes. Additionally, the method is robust to bit errors in the received sequence.
Solution-Time and data-storage requirements for the solution of full linear systems have become increasingly unwieldy with problem growth. Two parallel solution algorithms are proposed that can greatly decrease the so...
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Solution-Time and data-storage requirements for the solution of full linear systems have become increasingly unwieldy with problem growth. Two parallel solution algorithms are proposed that can greatly decrease the solution time of full systems by employing multiple processes in the problem solution. Furthermore, the algorithms lend themselves to extremely efficient operation on disk resident problems because of benign demands on data transfer to and from disk. The basis for algorithms is LU decomposition with partial row pivoting.
This article deals with the implementation of the P-Class PMU compliant with IEC/IEEE Standard 60255-118-1:2018 by usage of a multiple-resonator (MR)-based approach for harmonic analysis having been proposed recently....
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This article deals with the implementation of the P-Class PMU compliant with IEC/IEEE Standard 60255-118-1:2018 by usage of a multiple-resonator (MR)-based approach for harmonic analysis having been proposed recently. In previously published articles, it has been shown that a trade-off between opposite requirements is possible by shifting a measurement time stamp along the filter window. Positioning the time stamp in a proximity of the time window center assures flat-top frequency responses. In this article, through simulation tests carried out under various conditions, it is shown that requirements of the IEC/IEEE Standard 60255-118-1:2018 can be satisfied by the second and third order MR structure for particular conditions of the time stamp location.
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