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A novel interval arithmetic approach for solving differential-algebraic equations with VALENCIA-IVP

International Journal of Applied Mathematics and Computer Science

The theoretical background and the implementation of a new interval arithmetic approach for solving sets of differentialalgebraic equations (DAEs) are presented. The proposed approach computes guaranteed enclosures of all reachable states of dynamical systems described by sets of DAEs with uncertainties in both initial conditions and system parameters. The algorithm is based on VALENCIA-IVP, which has been developed recently for the computation of verified enclosures of the solution sets of initial...

A verified method for solving piecewise smooth initial value problems

International Journal of Applied Mathematics and Computer Science

In many applications, there is a need to choose mathematical models that depend on non-smooth functions. The task of simulation becomes especially difficult if such functions appear on the right-hand side of an initial value problem. Moreover, solution processes from usual numerics are sensitive to roundoff errors so that verified analysis might be more useful if a guarantee of correctness is required or if the system model is influenced by uncertainty. In this paper, we provide a short overview...

An algorithm for checking Hurwitz stability of K-symmetrizable interval matrices

Control and Cybernetics

An iterative algorithm for testing solvability of max-min interval systems

Kybernetika

This paper is dealing with solvability of interval systems of linear equations in max-min algebra. Max-min algebra is the algebraic structure in which classical addition and multiplication are replaced by $\oplus$ and $\otimes$, where $a\oplus b=max\left\{a,b\right\},a\otimes b=min\left\{a,b\right\}$. The notation $𝔸\otimes x=𝕓$ represents an interval system of linear equations, where $𝔸=\left[\underline{A},\overline{A}\right]$ and $𝕓=\left[\underline{b},\overline{b}\right]$ are given interval matrix and interval vector, respectively. We can define several types of solvability of interval systems. In this paper, we define the T4 and T5 solvability and give necessary and...

Bounding the maximum value of the real-valued sequence.

JIPAM. Journal of Inequalities in Pure &amp; Applied Mathematics [electronic only]

Computing discrete convolutions with verified accuracy via Banach algebras and the FFT

Applications of Mathematics

We introduce a method to compute rigorous component-wise enclosures of discrete convolutions using the fast Fourier transform, the properties of Banach algebras, and interval arithmetic. The purpose of this new approach is to improve the implementation and the applicability of computer-assisted proofs performed in weighed ${\ell }^{1}$ Banach algebras of Fourier/Chebyshev sequences, whose norms are known to be numerically unstable. We introduce some application examples, in particular a rigorous aposteriori...

Control of constrained nonlinear uncertain discrete-time systems via robust controllable sets: a modal interval analysis approach

ESAIM: Control, Optimisation and Calculus of Variations

A general framework for computing robust controllable sets of constrained nonlinear uncertain discrete-time systems as well as controlling such complex systems based on the computed robust controllable sets is introduced in this paper. The addressed one-step control approach turns out to be a robust model predictive control scheme with feasible unit control horizon and contractive constraint. The solver of 1-dimensional quantified set inversion in modal interval analysis is extended to 2-dimensional...

Derivation of physically motivated constraints for efficient interval simulations applied to the analysis of uncertain dynamical systems

International Journal of Applied Mathematics and Computer Science

Interval arithmetic techniques such as VALENCIA-IVP allow calculating guaranteed enclosures of all reachable states of continuous-time dynamical systems with bounded uncertainties of both initial conditions and system parameters. Considering the fact that, in naive implementations of interval algorithms, overestimation might lead to unnecessarily conservative results, suitable consistency tests are essential to obtain the tightest possible enclosures. In this contribution, a general framework for...

Deterministic global optimization using interval constraint propagation techniques

RAIRO - Operations Research - Recherche Opérationnelle

The purpose of this article is to show the great interest of the use of propagation (or pruning) techniques, inside classical interval Branch-and-Bound algorithms. Therefore, a propagation technique based on the construction of the calculus tree is entirely explained and some properties are presented without the need of any formalism (excepted interval analysis). This approach is then validated on a real example: the optimal design of an electrical rotating machine.

Deterministic global optimization using interval constraint propagation techniques

RAIRO - Operations Research

The purpose of this article is to show the great interest of the use of propagation (or pruning) techniques, inside classical interval Branch-and-Bound algorithms. Therefore, a propagation technique based on the construction of the calculus tree is entirely explained and some properties are presented without the need of any formalism (excepted interval analysis). This approach is then validated on a real example: the optimal design of an electrical rotating machine.

Evolutionary optimization of interval mathematics-based design of a TSK fuzzy controller for anti-sway crane control

International Journal of Applied Mathematics and Computer Science

A hybrid method combining an evolutionary search strategy, interval mathematics and pole assignment-based closed-loop control synthesis is proposed to design a robust TSK fuzzy controller. The design objective is to minimize the number of linear controllers associated with rule conclusions and tune the triangular-shaped membership function parameters of a fuzzy controller to satisfy stability and desired dynamic performances in the presence of system parameter variation. The robust performance objective...

Fault diagnosis and fault tolerant control using set-membership approaches: Application to real case studies

International Journal of Applied Mathematics and Computer Science

This paper reviews the use of set-membership methods in fault diagnosis (FD) and fault tolerant control (FTC). Setmembership methods use a deterministic unknown-but-bounded description of noise and parametric uncertainty (interval models). These methods aims at checking the consistency between observed and predicted behaviour by using simple sets to approximate the exact set of possible behaviour (in the parameter or the state space). When an inconsistency is detected between the measured and predicted...

Interval analysis for certified numerical solution of problems in robotics

International Journal of Applied Mathematics and Computer Science

Interval analysis is a relatively new mathematical tool that allows one to deal with problems that may have to be solved numerically with a computer. Examples of such problems are system solving and global optimization, but numerous other problems may be addressed as well. This approach has the following general advantages: (a) it allows to find solutions of a problem only within some finite domain which make sense as soon as the unknowns in the problem are physical parameters; (b) numerical computer...

Interval linear regression analysis based on Minkowski difference – a bridge between traditional and interval linear regression models

Kybernetika

In this paper, we extend the traditional linear regression methods to the (numerical input)-(interval output) data case assuming both the observation/measurement error and the indeterminacy of the input-output relationship. We propose three different models based on three different assumptions of interval output data. In each model, the errors are defined as intervals by solving the interval equation representing the relationship among the interval output, the interval function and the interval...

Nonsingularity, positive definiteness, and positive invertibility under fixed-point data rounding

Applications of Mathematics

For a real square matrix $A$ and an integer $d\ge 0$, let ${A}_{\left(d\right)}$ denote the matrix formed from $A$ by rounding off all its coefficients to $d$ decimal places. The main problem handled in this paper is the following: assuming that ${A}_{\left(d\right)}$ has some property, under what additional condition(s) can we be sure that the original matrix $A$ possesses the same property? Three properties are investigated: nonsingularity, positive definiteness, and positive invertibility. In all three cases it is shown that there exists a real number...

On an algorithm for testing T4 solvability of max-plus interval systems

Kybernetika

In this paper, we shall deal with the solvability of interval systems of linear equations in max-plus algebra. Max-plus algebra is an algebraic structure in which classical addition and multiplication are replaced by $\oplus$ and $\otimes$, where $a\oplus b=max\left\{a,b\right\}$, $a\otimes b=a+b$. The notation $𝔸\otimes x=𝕓$ represents an interval system of linear equations, where $𝔸=\left[\overline{b},\overline{A}\right]$ and $𝕓=\left[\underline{b},\overline{b}\right]$ are given interval matrix and interval vector, respectively. We can define several types of solvability of interval systems. In this paper, we define the T4 solvability and give an algorithm...

Set arithmetic and the enclosing problem in dynamics

Annales Polonici Mathematici

We study the enclosing problem for discrete and continuous dynamical systems in the context of computer assisted proofs. We review and compare the existing methods and emphasize the importance of developing a suitable set arithmetic for efficient algorithms solving the enclosing problem.

Stochastic Arithmetic Theory and Experiments

Serdica Journal of Computing

Stochastic arithmetic has been developed as a model for exact computing with imprecise data. Stochastic arithmetic provides confidence intervals for the numerical results and can be implemented in any existing numerical software by redefining types of the variables and overloading the operators on them. Here some properties of stochastic arithmetic are further investigated and applied to the computation of inner products and the solution to linear systems. Several numerical experiments are performed showing...

The automatic computation of second-order slope tuples for some nonsmooth functions.

ETNA. Electronic Transactions on Numerical Analysis [electronic only]

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