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Wyszukujesz frazę "parameter" wg kryterium: Temat


Tytuł:
Parameter identifiability for nonlinear LPV models
Autorzy:
Srinivasarengan, Krishnan
Ragot, José
Aubrun, Christophe
Maquin, Didier
Powiązania:
https://bibliotekanauki.pl/articles/2134053.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
parameter identifiability
parameter estimation
linear parameter varying model
parity space approach
null space
identyfikacja parametrów
szacowanie parametrów
spacja zerowa
Opis:
Linear parameter varying (LPV) models are being increasingly used as a bridge between linear and nonlinear models. From a mathematical point of view, a large class of nonlinear models can be rewritten in LPV or quasi-LPV forms easing their analysis. From a practical point of view, that kind of model can be used for introducing varying model parameters representing, for example, nonconstant characteristics of a component or an equipment degradation. This approach is frequently employed in several model-based system maintenance methods. The identifiability of these parameters is then a key issue for estimating their values based on which a decision can be made. However, the problem of identifiability of these models is still at a nascent stage. In this paper, we propose an approach to verify the identifiability of unknown parameters for LPV or quasi-LPV state-space models. It makes use of a parity-space like formulation to eliminate the states of the model. The resulting input-output-parameter equation is analyzed to verify the identifiability of the original model or a subset of unknown parameters. This approach provides a framework for both continuous-time and discrete-time models and is illustrated through various examples.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2022, 32, 2; 255--269
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distributed scheduling of sensor networks for identification of spatio-temporal processes
Autorzy:
Patan, M.
Powiązania:
https://bibliotekanauki.pl/articles/331419.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
układ o parametrach rozłożonych
estymacja parametrów
pomiar skaningowy
sieć sensorowa
distributed parameter system
parameter estimation
running consensus
scanning measurements
Opis:
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 in lieu of individual sensor positions. Then, based on the adaptation of pairwise communication algorithms and the idea of running consensus, a numerical scheme is developed which distributes the computational burden between the network nodes. As a result, a simple exchange algorithm is outlined to solve the design problem in a decentralized fashion.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 2; 299-311
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal Selection of Measurement Locations for Parameter Estimation in Distributed Processes
Autorzy:
Uciński, D.
Powiązania:
https://bibliotekanauki.pl/articles/911191.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
czujnik lokacyjny
rozproszony system komputerowy
estymacja parametryczna
sensor location
distributed-parameter systems
parameter estimation
optimum experimental design
spatial statistics
Opis:
The problem of locating pointwise sensor measurements so as to optimally estimate unknown parameters in a class of distributed systems is studied. Based on a scalar measure of performance defined on the corresponding Fisher information matrix, two approaches are developed for this problem: introduction of continuous designs, which allows for adaptation of well-known sequential algorithms of classical optimum experimental design, and application of standard non-linear programming techniques. In each case, particular algorithms are delineated and analysis of the appropriate sensor placements is made. The relative advantages and shortcomings of both the approaches are discussed and demonstrated by applying them to a two-dimensional diffusion process.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2000, 10, 2; 357-379
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distributed scheduling of measurements in a sensor network for parameter estimation of spatio-temporal systems
Autorzy:
Patan, M.
Kowalów, D.
Powiązania:
https://bibliotekanauki.pl/articles/331122.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sensor network
distributed parameter system
parameter estimation
experimental design
sensor scheduling
sieć sensorowa
układ o parametrach rozłożonych
estymacja parametrów
projekt eksperymentalny
Opis:
The main aim of the paper is to develop a distributed algorithm for optimal node activation in a sensor network whose measurements are used for parameter estimation of the underlying distributed parameter system. Given a fixed partition of the observation horizon into a finite number of consecutive intervals, the problem under consideration is to optimize the percentage of the total number of observations spent at given sensor nodes in such a way as to maximize the accuracy of system parameter estimates. To achieve this, the determinant of the Fisher information matrix related to the covariance matrix of the parameter estimates is used as the qualitative design criterion (the so-called D-optimality). The proposed approach converts the measurement scheduling problem to a convex optimization one, in which the sensor locations are given a priori and the aim is to determine the associated weights, which quantify the contributions of individual gaged sites to the total measurement plan. Then, adopting a pairwise communication scheme, a fully distributed procedure for calculating the percentage of observations spent at given sensor locations is developed, which is a major novelty here. Another significant contribution of this work consists in derivation of necessary and sufficient conditions for the optimality of solutions. As a result, a simple and effective computational scheme is obtained which can be implemented without resorting to sophisticated numerical software. The delineated approach is illustrated by simulation examples of a sensor network design for a two-dimensional convective diffusion process.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2018, 28, 1; 39-54
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensor network scheduling for identification of spatially distributed processes
Autorzy:
Uciński, D.
Powiązania:
https://bibliotekanauki.pl/articles/331382.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sieć sensorowa
estymacja parametrów
układ o parametrach rozłożonych
macierz informacyjna Fishera
sensor network
parameter estimation
distributed parameter system
optimum experimental design
Fisher information matrix
Opis:
The work treats the problem of fault detection for processes described by partial differential equations as that of maximizing the power of a parametric hypothesis test which checks whether or not system parameters have nominal values. A simple node activation strategy is discussed for the design of a sensor network deployed in a spatial domain that is supposed to be used while detecting changes in the underlying parameters which govern the process evolution. The setting considered relates to a situation where from among a finite set of potential sensor locations only a subset of them can be selected because of the cost constraints. As a suitable performance measure, the Ds-optimality criterion defined on the Fisher information matrix for the estimated parameters is applied. The problem is then formulated as the determination of the density of gauged sites so as to maximize the adopted design criterion, subject to inequality constraints incorporating a maximum allowable sensor density in a given spatial domain. The search for the optimal solution is performed using a simplicial decomposition algorithm. The use of the proposed approach is illustrated by a numerical example involving sensor selection for a two-dimensional diffusion process.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 1; 25-40
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive modeling of reliability properties for control and supervision purposes
Autorzy:
Dettmann, K. U.
Söffker, D.
Powiązania:
https://bibliotekanauki.pl/articles/907535.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
niezawodność
estymacja parametrów
kumulacja uszkodzeń
reliability
parameter estimation
damage accumulation
probabilistic simulation
Opis:
Modeling of reliability characteristics typically assumes that components and systems fail if a certain individual damage level is exceeded. Every (mechanical) system damage increases irreversibly due to employed loading and (mechanical) stress, respectively. The main issue of damage estimation is adequate determination of the actual state-of-damage. Several mathematical modeling approaches are known in the literature, focusing on the task of how loading effects damage progression (e.g., Wöhler, 1870) for wear processes. Those models are only valid for specific loading conditions, a priori assumptions, set points, etc. This contribution proposes a general model, covering adequately the deterioration of a set of comparable systems under comparable loading. The main goal of this contribution is to derive the loading-damage connection directly from observation without assuming any damage models at the outset. Moreover, the connection is not investigated in detail (e.g., to examine the changes in material, etc.) but only approximated with a probabilistic approach. The idea is subdivided into two phases: A problem-specific relation between loading applied (to a structure, which contributes to the stress) and failure is derived from simulation, where a probabilistic approach only assumes a distribution function. Subsequently, an adequate general model is set up to describe deterioration progression. The scheme will be shown through simulation-based results and can be used for estimation of the remaining useful life and predictive maintenance/control.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2011, 21, 3; 479-486
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial Compensation of Boundary Disturbances by Boundary Actuators
Autorzy:
Afifi, L.
Chafiai, A.
El Jai, A.
Powiązania:
https://bibliotekanauki.pl/articles/908071.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system z rozproszonymi parametrami
nastawnik
sterowanie
distributed-parameter systems
remediability
controllability
actuators
sensors
Opis:
In this paper we show how to find convenient boundary actuators, termed boundary efficient actuators, ensuring finite-time space compensation of any boundary disturbance. This is the so-called remediability problem. Then we study the relationship between this remediability notion and controllability by boundary actuators, and hence the relationship between boundary strategic and boundary efficient actuators. We also determine the set of boundary remediable disturbances, and for a boundary disturbance, we give the optimal control ensuring its compensation.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2001, 11, 4; 899-920
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of a Quasilinear Parabolic Equation from Final Data
Autorzy:
Fernandez, L. A.
Pola, C.
Powiązania:
https://bibliotekanauki.pl/articles/908074.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
quasi-liniowy
zagadnienie odwrotności
oznaczenie parametru
quasilinear parabolic equation
inverse problem
parameter estimation
Opis:
We study the identification of the nonlinearities A, vec{b} and c appearing in the quasilinear parabolic equation y_t - div (A(y) nabla y + vec{b} (y)) + c(y) = u in Omega x (0,T), assuming that the solution of an associated boundary value problem is known at the terminal time, y(x,T), over a (probably small) subset of Omega, for each source term u. Our work can be divided into two parts. Firstly, the uniqueness of A, vec{b} and c is proved under appropriate assumptions. Secondly, we consider a finite-dimensional optimization problem that allows for the reconstruction of the nonlinearities. Some numerical results in the one-dimensional case are presented, even in the case of noisy data.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2001, 11, 4; 859-879
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An observability problem for a class of uncertain-parameter linear dynamic systems
Autorzy:
Oprzędkiewicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/908528.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
układ dynamiczny liniowy
układ o niepewnych parametrach
obserwowalność
linear uncertain-parameter dynamic systems
observability
Opis:
An observability problem for a class of linear, uncertain-parameter, time-invariant dynamic SISO systems is discussed. The class of systems under consideration is described by a finite dimensional state-space equation with an interval diagonal state matrix, known control and output matrices and a two-dimensional uncertain parameter space. For the system considered a simple geometric interpretation of the system spectrum can be given. The geometric interpretation of the system spectrum is the base for defining observability and non-observability areas for the discussed system. The duality principle allows us to test observablity using controllability criteria. For the uncertain-parameter system considered, some controllability criteria presented in the author’s previous papers are used. The results are illustrated with numerical examples.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2005, 15, 3; 331-338
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Configuring a sensor network for fault detection in distributed parameter systems
Autorzy:
Patan, M.
Uciński, D.
Powiązania:
https://bibliotekanauki.pl/articles/929887.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
metoda podziału i ograniczeń
ograniczony plan eksperymentu
układ o parametrach rozłożonych
detekcja uszkodzeń
estymacja parametryczna
rozmieszczanie czujników
branch-and-bound
constrained experimental design
distributed parameter system
fault detection
parameter estimation
sensor location
Opis:
The problem of fault detection in distributed parameter systems (DPSs) is formulated as that of maximizing the power of a parametric hypothesis test which checks whether or not system parameters have nominal values. A computational scheme is provided for the design of a network of observation locations in a spatial domain that are supposed to be used while detecting changes in the underlying parameters of a distributed parameter system. The setting considered relates to a situation where from among a finite set of potential sensor locations only a subset can be selected because of the cost constraints. As a suitable performance measure, the Ds-optimality criterion defined on the Fisher information matrix for the estimated parameters is applied. Then, the solution of a resulting combinatorial problem is determined based on the branch-and-bound method. As its essential part, a relaxed problem is discussed in which the sensor locations are given a priori and the aim is to determine the associated weights, which quantify the contributions of individual gauged sites. The concavity and differentiability properties of the criterion are established and a gradient projection algorithm is proposed to perform the search for the optimal solution. The delineated approach is illustrated by a numerical example on a sensor network design for a two-dimensional convective diffusion process.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2008, 18, 4; 513-524
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite-time adaptive modified function projective multi-lag generalized compound synchronization for multiple uncertain chaotic systems
Autorzy:
Li, Q.
Liu, S.
Chen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/331032.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
finite-time adaptive control
unknown parameter
chaotic system
sterowanie adaptacyjne
parametr nieznany
układ chaotyczny
Opis:
In this paper, for multiple different chaotic systems with fully unknown parameters, a novel synchronization scheme called ‘modified function projective multi-lag generalized compound synchronization’ is put forward. As an advantage of the new method, not only the addition and subtraction, but also the multiplication of multiple chaotic systems are taken into consideration. This makes the signal hidden channels more abundant and the signal hidden methods more flexible. By virtue of finite-time stability theory and an adaptive control technique, a finite-time adaptive control scheme is established to realize the finite-time synchronization and to properly evaluate the unknown parameters. A detailed theoretical derivation and a specific numerical simulation demonstrate the feasibility and validity of the advanced scheme.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2018, 28, 4; 613-624
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Planning identification experiments for cell signaling pathways: An NFκB case study
Autorzy:
Fujarewicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/908137.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
komórka
ścieżka sygnalizacyjna
projektowanie eksperymentu
estymacja parametrów
cell signaling pathways
experiment design
parameter estimation
Opis:
Mathematical modeling of cell signaling pathways has become a very important and challenging problem in recent years. The importance comes from possible applications of obtained models. It may help us to understand phenomena appearing in single cells and cell populations on a molecular level. Furthermore, it may help us with the discovery of new drug therapies. Mathematical models of cell signaling pathways take different forms. The most popular way of mathematical modeling is to use a set of nonlinear ordinary differential equations (ODEs). It is very difficult to obtain a proper model. There are many hypotheses about the structure of the model (sets of variables and phenomena) that should be verified. The next step, fitting the parameters of the model, is also very complicated because of the nature of measurements. The blotting technique usually gives only semi-quantitative observations, which are very noisy and collected only at a limited number of time moments. The accuracy of parameter estimation may be significantly improved by a proper experiment design. Recently, we have proposed a gradient-based algorithm for the optimization of a sampling schedule. In this paper we use the algorithm in order to optimize a sampling schedule for the identification of the mathematical model of the NF[...]B regulatory module, known from the literature. We propose a two-stage optimization approach: a gradient-based procedure to find all stationary points and then pair-wise replacement for finding optimal numbers of replicates of measurements. Convergence properties of the presented algorithm are examined.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 4; 773-780
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifiability and estimation of pharmacokinetic parameters for the ligands of the macrophage mannose receptor
Autorzy:
Verdiere, N.
Denis-Vidual, L
Joly-Blanchard, G.
Domurado, D.
Powiązania:
https://bibliotekanauki.pl/articles/908453.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
układ nieliniowy
identyfikowalność
estymacja parametrów
zastosowania biologiczne
nonlinear systems
identifiability
parameter estimation
biological applications
Opis:
The aim of this paper is numerical estimation of pharmacokinetic parameters of the ligands of the macrophage mannose receptor, without knowing a priori the values of these parameters. However, it first requires a model identifiability analysis, which is done by applying an algorithm implemented in a symbolic computation language. It is shown that this step can lead to a direct numerical estimation algorithm. In this way, a first estimate is computed from noisy simulated observations without a priori parameter values. Then the resulting parameter estimate is improved by using the classical least-squares method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2005, 15, 4; 517-526
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Continuity of Solutions of Riccati Equations for the Discrete-Time Jlqp
Autorzy:
Czornik, A.
Świerniak, A.
Powiązania:
https://bibliotekanauki.pl/articles/908498.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
automatyka
coupled algebraic Ricatti equations
jump parameter system
quadratic control
stochastic stabilizability
observability
robustness
sensitivity
Opis:
The continuity of the solutions of difference and algebraic coupled Riccati equations for the discrete-time Markovian jump linear quadratic control problem as a function of coefficients is verified. The line of reasoning goes through the use of the minimum property formulated analogously to the one for coupled continuous Riccati equations presented by Wonham and a set of comparison theorems.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2002, 12, 4; 539-543
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variable- and Fixed-Structure Augmented Interacting Multiple-Model Algorithms for Manoeuvring Ship Tracting Based on New Ship Models
Autorzy:
Semerdjiev, E.
Mihaylova, L.
Powiązania:
https://bibliotekanauki.pl/articles/911219.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model niepewności
estymacja parametryczna
Interacting Multiple Model (IMM) algorithm
model uncertainty
state and parameter estimation
Opis:
Real-world tracking applications are related to a number of difficulties caused by the presence of different kinds of uncertainty, e.g. unknown or incompletely known system models and statistics of random processes or abrupt changes in the system modes of functioning. These problems are especially complicated in the marine navigation practice, where the commonly-used simple models of rectilinear or curvilinear target motions are not adequate for highly non-linear dynamics of the manoeuvring ship motion. A solution to these problems is to derive more suitable descriptions of real ship dynamics and to design adaptive estimation algorithms. After an analysis of basic hydrodynamic models, new ship models are derived in the paper. They are implemented in two versions of the Interacting Multiple Model (IMM) algorithm which has become very popular recently. The first one is a standard IMM version based on fixed model structures (FS's). They represent various modes of ship motion, distinguished by their rates of turns. The same rate of turn is additionally adjusted in the proposed new augmented versions of the IMM (AIMM) algorithm by using FS's and variable structures (VS's) of adaptive models estimating the current change in the system control parameters. Monte Carlo simulation experiments indicate that the VS AIMM algorithm outperforms the FS AIMM and FS IMM ones with respect to both accuracy and adaptability.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2000, 10, 3; 591-604
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł

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