作者:
Qu, SCLaboratory of Chromatography
DEPg.Fac.Quimica Universidad Nacional Autonoma de Mexico Circuito interior Cd Universitaria/CP 04510 Mexico D.F.Mexico
This paper presents a new recursive algorithm for calculating end-to-end blocking probability (EEB) with an arbitrary fixed nonhierarchical routing (AFNR) in a circuit-switched network, The new algorithm improves the ...
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This paper presents a new recursive algorithm for calculating end-to-end blocking probability (EEB) with an arbitrary fixed nonhierarchical routing (AFNR) in a circuit-switched network, The new algorithm improves the worst bound of the computation amount (WBCA) for the EEB of a node pair given in Chan [2] 2(n-1) times, where n is the number of the loss paths in the path-loss sequence, The amount of its practical computation may be far lower than WBCA. For an extreme case, sequential office-control (SOC) routing, it is proportional to the number of the completion paths from origination node to destination node.
In this article, the problem on the estimation of the convolution model parameters is considered. The recursive algorithm for estimating model parameters is introduced from the orthogonal procedure of the data, the co...
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In this article, the problem on the estimation of the convolution model parameters is considered. The recursive algorithm for estimating model parameters is introduced from the orthogonal procedure of the data, the convergence of this algorithm is theoretically discussed, and a sufficient condition for the convergence criterion of the orthogonal procedure is given. According to this condition, the recursive algorithm is convergent to model wavelet A- = (1, α1,..., αq).
The electrodynamic tether (EDT) system is used as one of the end-of-life disposal technologies to deorbit defunct satellites with the benefit of Earth???s magnetic field and plasma environment. However, due to the fle...
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The electrodynamic tether (EDT) system is used as one of the end-of-life disposal technologies to deorbit defunct satellites with the benefit of Earth???s magnetic field and plasma environment. However, due to the flexibility of the conductive tether, the orbit-attitude coupling effects as well as the influence of Multiphysics fields, this system suffers from time-consuming computations using complicated mathematical model in long-term simulations. Therefore, this paper proposes a high-fidelity high-efficiency dynamics model for the EDT system, in which the tether libration and transverse motions are described by the articulated model, and the system equations are formulated using recursive dynamics algorithm. Computational cost of the recursive method is compared with a nonrecursive method, and the result shows that with the number of tether elements larger than 15, the recursive method would show better computational efficiency. Since the conductive tether tends to be kilometers long in application, this new model would definitely contribute to the numerical efficiency. In addition, simulations are conducted with 2 and 16 tether elements solutions. By comparing the obtained results, it is found that the two cases show large differences over time. For a long tether, it is reasonable to use a larger number of elements in the dynamics analysis. Besides, in order to suppress the libration motion and avoid unstable states in the EDT system, a current control strategy is proposed and verified by a deorbit simulation in low Earth orbit.
A new optimal linear attitude estimator is proposed for single-point attitude estimation using geometric approach, and a recursive optimal linear attitude estimator is developed through filtering noisy measurements. D...
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A new optimal linear attitude estimator is proposed for single-point attitude estimation using geometric approach, and a recursive optimal linear attitude estimator is developed through filtering noisy measurements. Dot and cross products are taken in order to eliminate the unknown parameters of relationships between measurements and Gibbs vector. The optimality criterion, which does not coincide with Wahba's constrained criterion, yields linear attitude estimate. A prior rotation is adopted to avoid singularity which occurs when the principal angle is close to pi. The recursive algorithm is achieved for the purpose of improving attitude accuracy using all past measurements. For long-term space missions, memory fading concept is introduced into recursive optimal linear attitude estimator. The optimal relative weighting is obtained through minimizing error propagation, and an efficient modification is proposed to significantly reduce the sudden increase of attitude error of recursive optimal linear attitude estimator in special cases. Numerical simulations show that the estimate of optimal linear attitude estimator is almost identical with that of the famous QUaternion ESTimator, and the accuracy provided by recursive optimal linear attitude estimator is over an order magnitude higher than that of optimal linear attitude estimator or QUaternion ESTimator in most cases.
recursive algorithms for the estimation of mixtures of densities have attracted a lot of attention in the last 10 years. Here an algorithm for recursive estimation is studied. It complements existing approaches in the...
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recursive algorithms for the estimation of mixtures of densities have attracted a lot of attention in the last 10 years. Here an algorithm for recursive estimation is studied. It complements existing approaches in the literature, as it is based on conditions that are usually very weak. For example, the parameter space over which the mixture is taken does not need to be necessarily bounded. The essence of the procedure is to combine density estimation via empirical characteristic function together with an iterative Hilbert space approximation algorithm. The conditions for consistency of the estimator are verified for three important statistical problems. A simulation study is also included.
A new approach to the design of a digital algorithm for local system frequency estimation is presented. The algorithm is derived using the maximum likelihood method. One sinusoidal voltage model was assumed. FIR digit...
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A new approach to the design of a digital algorithm for local system frequency estimation is presented. The algorithm is derived using the maximum likelihood method. One sinusoidal voltage model was assumed. FIR digital filters used in papers [11], [12] are used to minimize the noise effect and to eliminate the presence of the harmonies effect. The algorithm showed a very high level of robustness as well as high measurement accuracy over a wide range of frequency changes. The algorithm convergence provided fast response and adaptability. This technique provides accurate estimates with error in the range of 0.005 Hz in about 25 ms and requires modest computations. The theoretical basis and practical implementation of the technique are described. To demonstrate the performance of the developed algorithm, computer simulated data records are processed.
作者:
Eidelman, YTel Aviv Univ
Raymond & Beverly Sackler Fac Exact Sci Sch Math Sci IL-69978 Tel Aviv Israel
In this paper, we continue the study of a class of structured matrices which may be treated as a generalization of the class of Hessenberg matrices. For this cl;class fast recursive algorithms for solution of the corr...
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In this paper, we continue the study of a class of structured matrices which may be treated as a generalization of the class of Hessenberg matrices. For this cl;class fast recursive algorithms for solution of the corresponding linear systems are obtained. The implementation of algorithms is illustrated by numerical experiments. (C) 2000 Elsevier Science Ltd. All rights reserved.
recursive algorithms have been found very effective for realization using software and very large scale integrated circuit (VLSI) techniques. Recently, some recursive algorithms have been proposed for the realization ...
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recursive algorithms have been found very effective for realization using software and very large scale integrated circuit (VLSI) techniques. Recently, some recursive algorithms have been proposed for the realization of the inverse discrete cosine transform (IDCT). In this paper, an efficient recursive algorithm for the IDCT with arbitrary length is presented. By using some appropriate iterative techniques, the formulation of the IDCT can be implemented effectively using recursive equations, and the hardware complexity is further reduced as compared with the approaches in the literature.
In this paper a recursive algorithm will be introduced to improve the differentiation method proposed by Hasan et al. (2012). Their algorithm is based on the undetermined coefficient method and uses the Taylor series ...
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In this paper a recursive algorithm will be introduced to improve the differentiation method proposed by Hasan et al. (2012). Their algorithm is based on the undetermined coefficient method and uses the Taylor series expansion and Vandermonde matrix inverse to calculate weighting coefficients with a complexity of O(n(4)). Our method reduces time complexity from O(n(4)) to O(n(3)). Moreover, we obtain a substantial optimality when the required degree and the order of accuracy increase. Finally, the implementation of the proposed method follows, and experimentations prove the validity of the algorithm and compare previous and new methods in terms of execution time. Besides, the combination of our optimization and parallel processing provides valuable results in real world applications. Particularly, QRS detection in ECG signal processing has been considered, and we have shown that how features of our method could be used in order to increase accuracy and speed for this application. (C) 2013 Elsevier B.V. All rights reserved.
In this article, based on least square estimation, a recursive algorithm for indirect learning structure predistorter is introduced. Simulation results show that of all polynomial predistorter nonlinear terms, higher-...
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In this article, based on least square estimation, a recursive algorithm for indirect learning structure predistorter is introduced. Simulation results show that of all polynomial predistorter nonlinear terms, higher-order (higher than 7th-order) nonlinear terms are so minor that they can be omitted in practical predistorter design. So, it is unnecessary to construct predistorter with higher-order polynomials, and the algorithm will always be stable. Further results show that even when 15th-order polynomial model is used, the algorithm is convergent after 10 iterations, and it can improve out-band spectrum of 20 MHz bandwidth signal by 64 dB, with a 1.2×10^11 matrix condition number.
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