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Copula approach to residuals of regime-switching models

Anna Petričková, Magda Komorníková (2012)

Kybernetika

The autocorrelation function describing the linear dependence is not suitable for description of residual dependence of the regime-switching models. In this contribution, inspired by Rakonczai ([20]), we will model the residual dependence of the regime-switching models (SETAR, LSTAR and ESTAR) with the autocopulas (Archimedean, EV and their convex combinations) and construct improved quality models for the original real time series.

Decomposition of vibration signals into deterministic and nondeterministic components and its capabilities of fault detection and identification

Tomasz Barszcz (2009)

International Journal of Applied Mathematics and Computer Science

The paper investigates the possibility of decomposing vibration signals into deterministic and nondeterministic parts, based on the Wold theorem. A short description of the theory of adaptive filters is presented. When an adaptive filter uses the delayed version of the input signal as the reference signal, it is possible to divide the signal into a deterministic (gear and shaft related) part and a nondeterministic (noise and rolling bearings) part. The idea of the self-adaptive filter (in the literature...

Design of a model following control system for nonlinear descriptor system in discrete time

Shujing Wu, Shigenori Okubo, Dazhong Wang (2008)

Kybernetika

A model following control system (MFCS) can output general signals following the desired ones. In this paper, a method of nonlinear MFCS will be extended to be a nonlinear descriptor system in discrete time. The nonlinear system studied in this paper has the property of norm constraint | | f ( v ( k ) ) | | α + β | | v ( k ) | | γ , where α 0 , β 0 , 0 γ < 1 . In this case, a new criterion is proposed to ensure the internal states be stable.

Detection and accommodation of second order distributed parameter systems with abrupt changes in input term: stability and adaptation

Michael A. Demetriou, Marios M. Polycarpou (1998)

Kybernetika

In this note, we employ nonlinear on-line parameter estimation methods based on adaptive neural network approximators for detecting changes due to actuator faults in a class of second order distributed parameter systems. The motivating example is a cantilevered beam actuated via a pair of piezoceramic patches. We examine changes in the control input term, which provide a simple and practical model of actuator failures. Using Lyapunov redesign methods, a stable learning scheme for fault diagnosis...

Distributed H estimation for moving target under switching multi-agent network

Hu Chen, Qin Weiwei, He Bing, Liu Gang (2015)

Kybernetika

In this paper, the distributed H estimation problem is investigated for a moving target with local communication and switching topology. Based on the solution of the algebraic Riccati equation, a recursive algorithm is proposed using constant gain. The stability of the proposed algorithm is analysed by using the Lyapounov method, and a lower bound for estimation errors is obtained for the proposed common H filter. Moreover, a bound for the H parameter is obtained by means of the solution of the...

Distributed scheduling of sensor networks for identification of spatio-temporal processes

Maciej Patan (2012)

International Journal of Applied Mathematics and Computer Science

An approach to determine a scheduling policy for a sensor network monitoring some spatial domain in order to identify unknown parameters of a distributed system is discussed. Given a finite number of possible sites at which sensors are located, the activation schedule for scanning sensors is provided so as to maximize a criterion defined on the Fisher information matrix associated with the estimated parameters. The related combinatorial problem is relaxed through operating on the density of sensors...

DUCS copulas

Radko Mesiar, Monika Pekárová (2010)

Kybernetika

Based on a recent representation of copulas invariant under univariate conditioning, a new class of copulas linked to a distortion of the identity function is introduced and studied.

Dynamic approach to optimum synthesis of a four-bar mechanism using a swarm intelligence algorithm

Edgar A. Portilla-Flores, Maria B. Calva-Yáñez, Miguel G. Villarreal-Cervantes, Paola A. Niño Suárez, Gabriel Sepúlveda-Cervantes (2014)

Kybernetika

This paper presents a dynamic approach to the synthesis of a crank-rocker four-bar mechanism, that is obtained by an optimization problem and its solution using the swarm intelligence algorithm called Modified-Artificial Bee Colony (M-ABC). The proposed dynamic approach states a mono-objective dynamic optimization problem (MODOP), in order to obtain a set of optimal parameters of the system. In this MODOP, the kinematic and dynamic models of the whole system are consider as well as a set of constraints...

Eigenspace of a three-dimensional max-Łukasiewicz fuzzy matrix

Imran Rashid, Martin Gavalec, Sergeĭ Sergeev (2012)

Kybernetika

Eigenvectors of a fuzzy matrix correspond to stable states of a complex discrete-events system, characterized by a given transition matrix and fuzzy state vectors. Description of the eigenspace (set of all eigenvectors) for matrices in max-min or max-drast fuzzy algebra was presented in previous papers. In this paper the eigenspace of a three-dimensional fuzzy matrix in max-Łukasiewicz algebra is investigated. Necessary and sufficient conditions are shown under which the eigenspace restricted to...

Estimation of feedwater heater parameters based on a grey-box approach

Tomasz Barszcz, Piotr Czop (2011)

International Journal of Applied Mathematics and Computer Science

The first-principle modeling of a feedwater heater operating in a coal-fired power unit is presented, along with a theoretical discussion concerning its structural simplifications, parameter estimation, and dynamical validation. The model is a part of the component library of modeling environments, called the Virtual Power Plant (VPP). The main purpose of the VPP is simulation of power generation installations intended for early warning diagnostic applications. The model was developed in the Matlab/Simulink...

Finite-time output feedback stabilization and control for a quadrotor mini-aircraft

Chuanlin Zhang, Shihua Li, Shihong Ding (2012)

Kybernetika

This paper focuses on the finite-time output feedback control problem for a quad-rotor mini-aircraft system. First, a finite-time state feedback controller is designed by utilizing the finite-time control theory. Then, considering the case that the velocity states are not measurable, a finite-time stable observer is developed to estimate the unmeasurable states. Thus a finite-time output feedback controller is obtained and the stability analysis is provided to ensure the finite-time stability of...

Fusion based analysis of ophthalmologic image data

Jiří Jan, Radim Kolář, Libor Kubečka, Jan Odstrčilík, Jiří Gazárek (2011)

Kybernetika

The paper presents an overview of image analysis activities of the Brno DAR group in the medical application area of retinal imaging. Particularly, illumination correction and SNR enhancement by registered averaging as preprocessing steps are briefly described; further mono- and multimodal registration methods developed for specific types of ophthalmological images, and methods for segmentation of optical disc, retinal vessel tree and autofluorescence areas are presented. Finally, the designed methods...

Fuzzy empirical distribution function: Properties and application

Gholamreza Hesamian, S. M. Taheri (2013)

Kybernetika

The concepts of cumulative distribution function and empirical distribution function are investigated for fuzzy random variables. Some limit theorems related to such functions are established. As an application of the obtained results, a method of handling fuzziness upon the usual method of Kolmogorov-Smirnov one-sample test is proposed. We transact the α -level set of imprecise observations in order to extend the usual method of Kolmogorov-Smirnov one-sample test. To do this, the concepts of fuzzy...

Generalized kernel regression estimatefor the identification of Hammerstein systems

Grzegorz Mzyk (2007)

International Journal of Applied Mathematics and Computer Science

A modified version of the classical kernel nonparametric identification algorithm for nonlinearity recovering in a Hammerstein system under the existence of random noise is proposed. The assumptions imposed on the unknown characteristic are weak. The generalized kernel method proposed in the paper provides more accurate results in comparison with the classical kernel nonparametric estimate, regardless of the number of measurements. The convergence in probability of the proposed estimate to the unknown...

Global finite-time stabilization for a class of stochastic nonlinear systems by dynamic state feedback

Weiqing Ai, Junyong Zhai, Shumin Fei (2013)

Kybernetika

This paper addresses the problem of global finite-time stabilization by dynamic state feedback for a class of stochastic nonlinear systems. Firstly, we show a dynamic state transformation, under which the original system is transformed into a new system. Then, a state feedback controller with a dynamic gain is designed for the new system. It is shown that global finite-time stabilization in probability for a class of stochastic nonlinear system under linear growth condition can be guaranteed by...

Global robust output regulation of a class of nonlinear systems with nonlinear exosystems

Yuan Jiang, Ke Lu, Jiyang Dai (2020)

Kybernetika

An adaptive output regulation design method is proposed for a class of output feedback systems with nonlinear exosystem and unknown parameters. A new nonlinear internal model approach is developed in the present study that successfully converts the global robust output regulation problem into a robust adaptive stabilization problem for the augmented system. Moreover, an output feedback controller is achieved based on a type of state filter which is designed for the transformed augmented system....

Goodman-Kruskal Measure of Association for Fuzzy-Categorized Variables

S. M. Taheri, Gholamreza Hesamian (2011)

Kybernetika

The Goodman-Kruskal measure, which is a well-known measure of dependence for contingency tables, is generalized to the case when the variables of interest are categorized by linguistic terms rather than crisp sets. In addition, to test the hypothesis of independence in such contingency tables, a novel method of decision making is developed based on a concept of fuzzy p -value. The applicability of the proposed approach is explained using a numerical example.

Graphics card as a cheap supercomputer

Přikryl, Jan (2013)

Programs and Algorithms of Numerical Mathematics

The current powerful graphics cards, providing stunning real-time visual effects for computer-based entertainment, have to accommodate powerful hardware components that are able to deliver the photo-realistic simulation to the end-user. Given the vast computing power of the graphics hardware, its producers very often offer a programming interface that makes it possible to use the computational resources of the graphics processors (GPU) to more general purposes. This step gave birth to the so-called...

Currently displaying 21 – 40 of 117