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Adaptive Equalization of Digital Line-Of-Sight Radio Systems

IFAC Proceedings Volumes 1992年第14期25卷 505-510页

作者： H. Sari Société Anonyme de Télécommunications 11 rue Watt B.P. 370 75626 Paris Cedex 13 France

This paper gives a state-of-the-art review of adaptive channel equalization in digital line-of-sight radio systems employing bandwidth-efficient modulation techniques. A particular emphasis is placed on decision-feedback equalizer (DFE) implementation and performance in the presence of nonminimum-phase fading. Stability problems of fractionally-spaced equalizers (FSE's) are discussed, and a newly developed adaptation technique is outlined. We also discuss the blind adaptation algorithms that are used to reduce outage by preventing the equalizer coefficients to diverge during severe fade events and carrier synchronism loss. Finally, we discuss further issues related to asymmetric equalizers and to the interaction of the equalizer adaptation algorithm with the carrier recovery loop.

关键词： Adaptive systems Adaptive equalization Data transmission Digital radio systems Fading channels Nyquist criterion recursive algorithms

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MODELLING OF NON STATIONARY SYSTEMS BASED ON A DYNAMICAL DECISION SPACE

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IFAC Proceedings Volumes 2006年第1期39卷 1222-1227页

作者： S. Lecœuche G. Mercère H. Amadou-Boubacar LAGIS - UMR CNRS 8146 Département G.I.P. Mines de Douai 59508 Douai Cedex Phone: +33(0)327712445 Fax : +33(0)327712980 Laboratoire d'Automatique et d'Informatique Industrielle 40 avenue du recteur Pineau 86022 Poitiers France Phone: + 33 (0)549453509 Fax: +33 (0)549454034

A new approach based on pattern recognition techniques and dedicated to the monitoring of non stationary systems is presented in this paper. More precisely, it consists of a recursive subspace identification algorithm combined with an adaptive classifier set for non stationary environment. The system identification method which provides a recursive estimation of a linear state space model is firstly described. Then, a feature vector representing the system functioning state is extracted from this estimated model. Next, the dynamical clustering algorithm which online learns the functioning modes and continuously determines the current mode of the system is introduced. Its auto adaptive and unsupervised abilities to take into account system modes evolutions are finally emphasized on simulation examples.

关键词： Monitoring Pattern Recognition System identification recursive algorithms Subspace methods Systems tracking Non stationary systems Classification

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Adaptive Error Based Thresholding for On-Line Wavelet Compression

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IFAC Proceedings Volumes 1999年第2期32卷 6680-6685页

作者： Manish Misra Shailesh Kumar S. Joe Qin Dick Seemann Department of Chemical Engineering University of Texas at Austin Austin TX 78712 USA Fisher Rosemount Systems Inc. 1712 Centre Creek Drive Austin TX 78754 USA

Wavelet based data compression is superior to interpolative compression techniques like boxcar as wavelets provide an efficient joint time-scale representation of the signal in terms of wavelet coefficients. Thresholding over these coefficients is used to achieve compression. A recursive on-line wavelet based compression algorithm, which combines the high quality of compression of wavelets and on-line implementability of interpolative methods has already been developed. In this paper, an error based thresholding framework is introduced, which adaptively computes these thresholds, given the bounds on root mean square error and local point error. This framework is applied to the recursive on-line wavelet based compression using Haar wavelets. Experiments show that the resulting algorithm gives superior compression as compared to interpolative methods. Moreover, it can be used on-line and provides an effective way of controlling the local point error (LPE) and the root mean square error (RMSE).

关键词： Data compression wavelets recursive algorithms error based thresholding

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A computational framework for the dynamic analyses of cable-driven parallel robots with feed and retrieval of cables

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MECHANISM AND MACHINE THEORY 2023年第1期186卷

作者： Mamidi, Teja Krishna Bandyopadhyay, Sandipan Indian Inst Technol Madras Dept Engn Design Chennai 600036 Tamil Nadu India

Accurate simulations of the motion of cable-driven parallel robots (CDPRs) are helpful in its modal analysis, testing robust control strategies, validating designs and estimating workspaces. On that account, a modular and computationally efficient framework to analyse the dynamics of CDPRs is developed in the present work. In contrast to the prior studies, the inertia, stiffness and damping properties of the cables, along with their temporal variations caused by feeding and retrieving, are included in the dynamic model. Further, the forward dynamics algorithm designed for this purpose is recursive in nature and has linear time complexity. Finally, the efficacy of the proposed framework is established with the help of the FAST manipulator, the largest existing CDPR. Also, its extensive application potential is established via the study of the CDPR CoGiRo, which, apart from being actuated redundantly, differs drastically from the former in terms of its mass and footprint.

关键词： Cable-driven parallel robot (CDPR) Five-hundred-meter aperture spherical radio (FAST) CoGiRo Forward dynamics recursive algorithms Numerical stiffness

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The Impact of Impulsive Traffic on Cellular Internet of Things Network Performance Indicators

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SENSORS 2024年第1期24卷 46页

作者： Dawood, Tammam Zuhair Stepanov, Mikhail Sergeevich Kudashkin, Matvey Shaimardanova, Arina Lapko, Petr Moscow Tech Univ Commun & Informat Fac Commun Networks & Syst 8AAviamotornaya Str Moscow 111024 Russia Tishreen Univ Fac Mech & Elect Engn POB 2237 Latakia Syria

The use of wireless sensor networks and the Internet of Things has increased dramatically in the last decade. The sensors measure the required parameters and send them to the data processing centers using one of the various wireless transmission technologies (often using cellular infrastructure) to make the appropriate decision. Files containing measurement information can arrive in bursts simultaneously, which is a critical issue to be aware of. The purpose of this work is to develop and analyze a model to evaluate the effectiveness of an LTE (Long-Term Evolution) cell in serving requests from NB-IoT (Narrowband Internet of things) devices when these requests are received in bursts rather than individually. In the article, the common uses of the Internet of Things in our modern era were discussed, the NB-IoT technology was paid attention to, and a mathematical model to evaluate the performance of an LTE cell in the case of impulsive arrivals of NB-IoT requests was built. Finally, the computational algorithm and numerical evaluation were introduced.

关键词： NB-IoT LTE LPWAN licensed spectrum recursive algorithms mathematical modeling

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recursive Construction of Optimal Smoothing Spline Surfaces with Constraints

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IFAC Proceedings Volumes 2011年第1期44卷 2278-2283页

作者： Hiroyuki Fujioka Hiroyuki Kano Department of System Management Fukuoka Institute of Technology Fukuoka 811-0295 JAPAN School of Science and Engineering Tokyo Denki University Saitama 350-0394 JAPAN

Abstract In this paper, we consider the problem of recursively constructing smoothing spline surfaces with equality and/or inequality constraints each time when a new set of data is observed. The splines are constituted by using normalized uniform B-splines as the basis functions. Then various types of constraints are formulated as linear function of the so-called control points, and the problem is reduced to quadratic programming problem. Based on the results, we develop the recursive design method for constructing such constrained smoothing spline surfaces. The performance is examined by some numerical examples.

关键词： Splines Smoothing Constraints recursive algorithms

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A recursive METHOD FOR MINIMAL SIPHON ENUMERATION IN PETRI NETS

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IFAC Proceedings Volumes 2005年第1期38卷 49-54页

作者： Arianna Benigno Roberto Cordone Luca Ferrarini Luigi Piroddi Dip. di Elettronica e Informazione Politecnico di Milano P.za L. Da Vinci 32 20133 Milano Italy Dip di Tecnologie dell'Informazione Università degli Studi di Milano Polo Didattico e di Ricerca di Crema Via Bramante 65 26013 Crema Italy

The enumeration of minimal siphons in ordinary Petri nets is fundamental in the assessment of behavioral properties and a crucial step in the development of deadlock prevention algorithms. A novel recursive algorithm is proposed in the paper for this purpose, based on theoretical results that extend well known properties described in the literature. The algorithm uses already found solutions to progressively decompose the search problem into smaller sub-problems. This recursive decomposition approach is combined with the LTUR procedure, which efficiently computes a siphon, based on a logical clause description approach. A prototypical version of the search algorithm has been developed and an experiment has been carried out on a large set of random test instances to evaluate the efficiency of the method.

关键词： Petri-nets Deadlock Search methods recursive algorithms Computational methods

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A recursive Modified Gram-Schmidt Identification with Directional Tracking of Parameters

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IFAC Proceedings Volumes 1991年第3期24卷 1103-1108页

作者： J. Kadlec Institute of Information Theory and Automation Czechoslovak Academy of Sciences Pod vodárenskou věži 4 18208 Praha 8 Czechoslovakia

The new version of the recursive Modified Gram- Schmidt algorithm with directional parameter tracking technique is presented for the input-output regression models. The directional forgetting improves significantly the numerical behavior of algorithm when data are not persistently exciting. The algorithm allows a highly modular and numerically safe implementation even if an extremely fast parameter tracking speed is desired. The algorithm works with a modular triangular structure of reflection coefficients. A comparative study demonstrates the improved numerical performance over the standard square root algorithms with the exponential parameter tracking.

关键词： Identification least-squares estimation adaptive systems multiprocessing systems parallel processing recursive algorithms

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Modeling Non-Linear Process Dynamics Using Partially Recurrent Neural Networks

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IFAC Proceedings Volumes 2000年第15期33卷 1049-1054页

作者： A.H. Adorn J.B. Gornm D. Williarns Control Systems Research Group School of Engineering Liverpool John Moores University Byrom Street Liverpool L3 3AF UK

The representation of non-linear process dynamics can cause problems for feedforward networks, and recurrent networks hold promise in this area. Two partially recurrent neural network structures with local output feedback are investigated, along with four training algorithms, for their ability to model non-linear processes. The training algorithms studied included two well-known backpropagation techniques and are all shown to be derivatives of the more general recursive prediction error (RPE) method. Networks were trained and tested on data from a simulated, non-linear chemical process. The performance of the partially recurrent networks is compared to a standard time delay neural network model. The results show that partially recurrent networks can model as well as time delay networks. Issues relating to the implementation of partially recurrent networks for non-linear modelling are discussed.

关键词： process identification neural networks neural dynamics recursive algorithms nonlinear models dynamic model

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recursive Dynamic Programming: Heuristic Rules, Bounding and State Space Reduction

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IFAC Proceedings Volumes 1995年第4期28卷 109-114页

作者： Henrik Kure Dina Danish Informatics Network In the Agricultural Sciences Royal Veterinary and Agricultural University Bulowsvej 13 DK-1870 Frb. Copenhagen.

An alternative approach towards dynamic programming (DP) is presented: Recursions. A basic deterministic model and solution function are defined and the model is generalized to include stochastic processes, with the traditional stochastic DP model as a special case. Heuristic rules are included in the models simply as restrictions on decision spaces and a small slaughter pig marketing planning example illustrates the potential state space reductions induces by such rules.

关键词： Dynamic programming recursive algorithms heuristics stochastic modelling

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