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NEW ROBUST AND FLEXIBLE PARAMETER-ESTIMATION METHOD

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第2期16卷 411-413页

作者： LIU, CY KUNG, MC CHEN, JC CHIANG, SM TAM KANG UNIV DEPT ELECTR ENGNTAIPEITAIWAN

The paper presents the derivation of the generalized maximum likelihood estimator (GME), using a very flexible distribution. The GME properties are determined from the basic theory of the M-estimator, and its robust r... 详细信息

关键词： recursive algorithm Flexible Structures Structural Dynamics Feedback Control Korea Aerospace Research Institute Aircraft Stability and Control Aerospace Engineering Fixed Wing Aircraft Cantilever Beam Vibration Suppression

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Second-order equations for rendezvous in a circular orbit

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2004年第3期27卷 499-501页

作者： Karlgaard, CD Lutze, FH Analyt Mech Associates Inc Hampton VA 23666 USA Virginia Polytech Inst & State Univ Dept Aerosp & Ocean Engn Blacksburg VA 24061 USA

This Note develops an approximate analytical solution of the two-body orbital boundary-value problem, known as Lambert's problem, using a time-explicit analytical solution of the relative motion problem. Explicitly stated, the problem is to determine the initial velocity of a satellite, given two position vectors and a time of flight between them. Although the classical origin of the problem related to the determination of planetary orbits, present-day applications are in the area of intercept and rendezvous guidance, where the initial velocity of a maneuvering spacecraft for which its position will coincide with a target position at a specified time must be determined.

关键词： Clohessy Wiltshire Equation Lambert's Problem Singular Value Decomposition Perturbation Method recursive algorithm Newton Raphson Method Flight Testing Rendezvous Guidance Nonlinear Dynamics Planetary Orbits

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Digital design of sigmoid approximator for artificial neural networks

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ELECTRONICS LETTERS 2002年第1期38卷 35-37页

作者： Basterretxea, K Tarela, JM del Campo, I Euskal Herriko Unibertsitatea EHUUPV EUITI Elekt & Telekomunikazio Saila Bilbao 48012 Basque Country Spain Euskal Herriko Unibertsitatea UPV EHU Zientzi Fak Leioa 48940 Basque Country Spain

A digital design for piecewise-linear (PWL) approximation to the sigmoid function is presented. Circuit operation is based on a recursive algorithm that uses lattice operators max and min to approximating nonlinear functions. The resulting hardware is programmable, allowing for the control of the delay-time/approximation-accuracy rate.

关键词： sigmoid approximator hardware implementation piecewise-linear approximation circuit operation Interpolation and function approximation (numerical analysis) Neural net devices integrated circuit design nonlinear function approximation Neural nets (circuit implementations) Digital circuit design, modelling and testing silicon area digital design artificial neural networks Semiconductor integrated circuit design, layout, modelling and testing neural chips VLSI function approximation recursive algorithm lattice operators piecewise linear techniques

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Frequency Estimation of Three-Phase Power System Using Weighted-Least-Square algorithm and Adaptive FIR Filtering

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2010年第2期59卷 322-329页

作者： Kusljevic, Miodrag D. Tomic, Josif J. Jovanovic, Ljubisa D. Termoelektro Enel AD Belgrade 11060 Serbia Univ Novi Sad Fac Tech Sci Dept Power Elect & Telecommun Engn Novi Sad 21000 Serbia Inst Mihailo Pupin Belgrade 11000 Serbia

A new technique for estimation of the instantaneous frequency based on simultaneous sampling of three-phase voltage signals is presented. The structure consists of two decoupled modules: the first is for adaptive filtering of input signals, and the second is for frequency estimation. A suitable and robust algorithm for frequency estimation is obtained. This technique provides better performance, compared with the technique based on a single-phase signal in relation to waveforms with noise. The technique is particularly important when asymmetric sags generate zero voltage in one of the three phases. In addition, it allows the measurement of the instantaneous frequency value of real signals for single- or three-phase systems. To demonstrate the performance of the developed algorithm, computer-simulated data records and calibrator-generated signals are processed. The proposed algorithm has been put to test with distorted three-phase voltage signals.

关键词： Adaptive filtering finite-impulse-response (FIR) filter frequency estimation frequency measurement harmonics median filter recursive algorithm three-phase power system

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Systematic modeling of a chain of N-flexible link manipulators connected by revolute-prismatic joints using recursive Gibbs-Appell formulation

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ARCHIVE OF APPLIED MECHANICS 2014年第2期84卷 187-206页

作者： Korayem, M. H. Shafei, A. M. Dehkordi, S. F. Iran Univ Sci & Technol Sch Mech Engn Dept Mech EngnRobot Res Lab Ctr Excellence Expt Solid Mech & Dynam Tehran 16846 Iran

The main intent of this paper is to represent a systematic algorithm capable of deriving the equations of motion of N-flexible link manipulators with revolute-prismatic joints. The existence of the prismatic joints together with the revolute ones makes the derivation of governing equations difficult. Also, the variations of the flexible parts of the links, with respect to time cause the associated mode shapes of the links to vary instantaneously. So, to derive the kinematic and dynamic equations of motion for such a complex system, the recursive Gibbs-Appell formulation is applied. For a comprehensive and accurate modeling of the system, the coupling effects due to the simultaneous rotating and reciprocating motions of the flexible arms as well as the dynamic interactions between large movements and small deflections are also included. In this study, the links are modeled based on the Euler-Bernoulli beam theory and the assumed mode method. Also, the effects of gravity as well as the longitudinal, transversal and torsional vibrations have been considered in the formulations. Moreover, a recursive algorithm based on 3 x 3 rotational matrices has been applied in order to derive the system's dynamic equations of motion, symbolically and systematically. Finally, a numerical simulation has been performed by means of a developed computer program in order to demonstrate the ability of this algorithm in deriving and solving the equations of motion related to such systems.

关键词： Revolute-prismatic joint Gibbs-Appell recursive algorithm Flexible link

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algorithm for Reliability Evaluation of Nonrepairable Phased-Mission Systems Consisting of Gradually Deteriorating Multistate Elements

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IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS 2013年第1期43卷 63-73页

作者： Levitin, Gregory Amari, Suprasad V. Xing, Liudong Univ Elect Sci & Technol China Collaborat Auton Comp Lab Sch Comp Sci Chengdu 610054 Peoples R China Israel Elect Corp Ltd IL-31000 Haifa Israel Parametr Technol Corp Greensburg PA 15601 USA Univ Massachusetts Dartmouth Dept Elect & Comp Engn N Dartmouth MA 02747 USA

Reliability analysis of phased-mission systems (PMS) must consider the statistical dependences of element states across different phases as well as changes in system configuration, success criteria, and component behavior. This paper proposes a recursive method for the exact reliability evaluation of PMS consisting of nonidentical independent nonrepairable multistate elements. The method is based on conditional probabilities and the branch-and-bound principle. It is invariant to changes in system structure, demand, and the elements' state transition rates among phases. The main advantage of this method is that it does not require the composition of decision diagrams and can be fully automated. Both analytical and numerical examples are presented to illustrate the application and advantages of the proposed method. The computational performance of the proposed algorithm is illustrated through comprehensive experimentation on the CPU running time of the algorithm.

关键词： Multistate element phased-mission systems (PMS) recursive algorithm reliability analysis

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The rupture degree of trees

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INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 2008年第11期85卷 1629-1635页

作者： Li, Yinkui Qinghai Nationalities Coll Dept Math Xining Qinghai Peoples R China

For the complete graph K-n, its rupture degree is defined as 1-n;and for a noncomplete connected graph G, its rupture degree is defined by r(G) = max{omega(G-X) - vertical bar X vertical bar - m(G-X) : X subset of V (G), omega(G-X) > 1}, where omega(G-X) is the number of components of G-X and m(G-X) is the order of a largest component of G - X. It is shown that this parameter can be well used to measure the vulnerability of networks. Li and Li proved in 2004 that computing the rupture degree for a general graph is NP-complete. In this paper, we give a recursive algorithm for computing the rupture degree of trees, and determine the maximum and minimum rupture degree of trees with given order and maximum degree.

关键词： rupture degree recursive algorithm tree

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Search for all d-MPs for all d levels in multistate two-terminal networks

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RELIABILITY ENGINEERING & SYSTEM SAFETY 2015年第Oct.期142卷 300-309页

作者： Bai, Guanghan Zuo, Ming J. Tian, Zhigang Univ Alberta Dept Mech Engn Edmonton AB Canada

A general method for reliability evaluation of multistate network is using minimal path vectors. A minimal path (MP) vector to system state d is called a d-MP. Most reported works on generating d-MPs are for a particular d value. However, if all d-MPs for all possible integer d values are required, we need to call such methods multiple times with respect to all d values. A more efficient method is desirable to generate all d-MPs. In this paper, we develop a recursive algorithm based on breadth-first search to search for all the d-MPs for all possible d values. The relationships among d-MPs for different d levels are revealed. Each d-MP candidate can be generated by a combination of one (d-1)-MP and the vector form of one binary minimal path. Thus, we can use binary MPs as building blocks to generate 2-MP candidates, and use 2-MPs and binary MPs as building blocks to generate 3-MP candidates ... and so forth. When the d-MPs with respect to the maximum d value have been found, all the d-MPs for all possible d values are obtained. A heuristic for pre-processing the MPs is proposed to improve the efficiency of the algorithm. Through computational experiments, it is found that the proposed algorithm is more efficient than existing algorithms for finding all d-MPs for all possible d values. In addition, we show that the proposed algorithm can also be used to generate a subset of d-MPs for all or some d values given a subset of MPs. The generated subset of d-MPs can be used for lower reliability bound evaluation. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Two-terminal networks Multistate reliability Minimal path vectors recursive algorithm

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Efficient MDCT recursive Structure for VLSI Implementation

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2020年第3期39卷 1372-1386页

作者： Dahiya, Pragati Jain, Priyanka Delhi Technol Univ Dept Elect & Commun Engn Bawana Rd Delhi India

Modified discrete cosine transform (MDCT) is a computationally intensive fundamental processing block for mapping time into frequency in various versions of MPEG audio coding. An efficient algorithm for MDCT computation is a basic requirement to realize low-cost audio codec. This paper introduces a new recursive algorithm and architecture for MDCT. The proposed architecture requires minimum hardware and execution time. Folding of the input sequence is performed multiple times in the subsequent groups which results in a significant reduction in real multiplication and real addition operations. Also, fewer number of execution cycles are required to generate the output through this algorithm. The proposed structure is suitable for parallel VLSI implementation as it is simple, regular and modular.

关键词： Modified discrete cosine transform (MDCT) Infinite impulse response (IIR) filter structure recursive algorithm Very large scale integrated circuits (VLSI) MPEG codec

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A bi-objective guillotine cutting problem of stamping strips of equal circles

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INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 2010年第12期87卷 2716-2721页

作者： Cui, Yaodong Gu, Tianlong Hu, Wei Guangxi Normal Univ Dept Comp Sci Guilin 541004 Peoples R China Guilin Univ Elect Technol Dept Comp Sci Guilin 541004 Peoples R China

Some factories use the cutting and stamping processes to divide stock plates into circles to make products. A guillotine machine cuts the plate into strips in the cutting process and then a stamping press punches out circles from the strips in the stamping process. The circles in a strip have the same size. The number of rows of circles in each strip is limited. Under these constraints, this paper addresses the following primary objective: to cut a plate by a guillotine method so that the maximal number of circles is obtained. Then the secondary objective should be optimized: the cutting layout should use a minimal number of strips. The problem is formulated as a bi-objective optimization problem and a recursive algorithm is presented for it. The computational results indicate that the algorithm can efficiently simplify the cutting process.

关键词： recursive algorithm two-dimensional cutting circle packing stamping strips

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