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Tytuł:
The grouping differential evolution algorithm for multi-dimensional optimization problems
Autorzy:
Piotrowski, A. P.
Napiórkowski, J. J.
Powiązania:
https://bibliotekanauki.pl/articles/969839.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
differential evolution
multidimensional problems
multimodal problems
metaheuristics
Opis:
A variant of the Differential Evolution method is presented. The classical Differential Evolution approach is very successful for simple problems, but does not perform well enough for troublesome multi-dimensional non-convex continuous functions. To overcome some of the drawbacks, the Grouped Multi-Strategy Differential Evolution algorithm is proposed here. The main idea behind the new approach is to exploit the knowledge about the local minima already found in different parts of the search space in order to facilitate further search for the global one. In the proposed method, the population is split into four groups: three of them rarely communicate with the others, but one is allowed to gain all available knowledge from the whole population throughout the search process. The individuals simultaneously use three different crossover/mutation strategies, which makes the algorithm more flexible. The proposed approach was compared with two Differential Evolution based algorithms on a set of 10- to 100-dimensional test functions of varying difficulty. The proposed method achieved very encouraging results; its advantage was especially significant when more difficult 50- and 100-dimensional problems were considered. When dividing population into separate groups, the total number of individuals becomes a crucial restriction. Hence, the impact of the number of individuals on the performance of the algorithms was studied. It was shown that increasing the number of individuals above the number initially proposed for classic Differential Evolution method is in most cases not advantageous and sometimes may even result in deterioration of results.
Źródło:
Control and Cybernetics; 2010, 39, 2; 527-550
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extensions of the control variational method
Autorzy:
Sprekels, J.
Tiba, D.
Powiązania:
https://bibliotekanauki.pl/articles/206097.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
optimal control
calculus of variations
contact problems
evolution problems
Opis:
The control variational method is a development of the variational approach, based on optimal control theory. In this work, we give an application to a variational inequality arising in mechanics and involving unilateral conditions both in the domain and on the boundary, and we explore the extension of the method to time-dependent problems.
Źródło:
Control and Cybernetics; 2011, 40, 4; 1099-1108
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Existence, uniqueness and convergence of simultaneous distributed-boundary optimal control problems
Autorzy:
Gariboldi, C. M.
Tarzia, D. A.
Powiązania:
https://bibliotekanauki.pl/articles/206574.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
simultaneous optimal control problems
mixed elliptic problems
optimality conditions
elliptic variational equalities
Opis:
We consider a steady-state heat conduction problem P for the Poisson equation with Mied Bondary conditions in a bounded multidimensional domain Ω. We also consider a family of problems Pα for the same Poisson equation with mixed boundary conditions, α > 0 being the heat transfer coefficient defined on a portion Γ1 of the boundary. We formulate simultaneous distributed and Neumann boundary optimal control problems on the internal energy g within Ω and the heat flux q, defined on the complementary portion Γ2 of the boundary of Ω for quadratic cost functional. Here, the control variable is the vector (g,q). We prove existence and uniqueness of the optimal control (g,q) for the system state of P, and (gα,qα) for the system state of Pα, for each α > 0, and we give the corresponding optimality conditions. We prove strong convergence, in suitable Sobolev spaces, of the vectorial optimal controls, system and adjoint states governed by the problems Pα to the corresponding vectorial optimal control, system and adjoint states governed by the problem P, when the parameter α goes to infinity. We also obtain estimations between the solutions of these vectorial optimal control problems and the solution of two scalar optimal control problems characterized by fixed g (with boundary optimal control q) and fixed q (with distributed optimal control g), respectively, for cases both of α > 0 and α = ∞.
Źródło:
Control and Cybernetics; 2015, 44, 1; 5-17
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A few words about history of extremal problems at Moscow University
Autorzy:
Tikhomirov, V. M.
Demidovich, V. B.
Powiązania:
https://bibliotekanauki.pl/articles/970919.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
Moscow University
history of extremal problems
Źródło:
Control and Cybernetics; 2009, 38, 4A; 997-999
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exponential and chaotic neurodynamical tabu searches for quadratic assignment problems
Autorzy:
Hasegawa, M.
Ikeguchi, T.
Aihara, K.
Powiązania:
https://bibliotekanauki.pl/articles/206864.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
problem optymalizacji kombinatorycznej
sieć neuronowa
chaos
combinatorial optimization problems
neural networks
quadratic assignment problems
tabu search
Opis:
We propose a chaotic neurodynamical searching method for the Quadratic Assignment Problems (QAPs). First, we construct a neural network whose behavior is the same as that of the conventional tabu search. Using the dynamics of the tabu search neural network, we realize the exponential tabu search, whose tabu effect decreases exponentially with time, and we show the effectiveness of this type of exponential tabu search. Next, we extend this novel tabu search to a chaotic version. This chaotic method includes both effects of the chaotic dynamical search and the exponential tabu search, and exhibits better performance than the conventional and exponential tabu searches. Last, we propose an automatic parameter tuning method and show that the proposed method exhibits high performance even on large QAPs.
Źródło:
Control and Cybernetics; 2000, 29, 3; 773-788
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimality and stability result for bang-bang optimal controls with simple and double switch behaviour
Autorzy:
Felgenhauer, U.
Poggiolini, L.
Stefani, G.
Powiązania:
https://bibliotekanauki.pl/articles/970776.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
bang-bang control
parametric control problems
Hamiltonian flows
Opis:
The paper considers parametric optimal control problems with bang-bang control vector function. For this problem we give regularity and second-order optimality conditions at the nominal solution which are sufficient to: (i) existence and local uniqueness of extremals, (ii) local structure stability, (iii) strong local optimality, under parameter perturbations. Here "local" means in a L∞ neighbourhood of the nominal trajectory, regardless of the control values. Stability results were obtained by the first author using the shooting approach, while optimality results were obtained by the other authors, using the Hamiltonian approach. The paper, combining both approaches, allows to unify the assumptions and to close some gaps between optimality and stability results.
Źródło:
Control and Cybernetics; 2009, 38, 4B; 1305-1325
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Existence conditions in symmetric multivalued vector quasiequilibrium problems
Autorzy:
Anh, L. Q.
Khanh, P. Q.
Powiązania:
https://bibliotekanauki.pl/articles/970286.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
symmetric quasiequilibrium problems
upper semicontinuity
0-level C-quasiconvexity relative to a set
lower and upper bounded quasiequilibrium problems
coincidence points
Opis:
We consider symmetric multivalued vector quasiequilibrium problems in topological vector spaces. Sufficient conditions for the solution existence are established under relaxed assumptions, which are shown by examples to be essential, easy to check and more advantageous than recent known results. Applications to lower and upper bounded quasiequilibrium problems and to coincidence point problems are given.
Źródło:
Control and Cybernetics; 2007, 36, 3; 519-530
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the inverse problems of Lyapunov theorem and Riccati equation
Autorzy:
Sun, Y.
Powiązania:
https://bibliotekanauki.pl/articles/205963.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
teoria systemu liniowego
zagadnienie odwrotne
inverse problems
linear systems theory
Opis:
In this note, the inverse problem of Lyapunov theorem is reconsidered and the inverse problem of Riccati equation is introduced. Simple proofs are provided to guarantee the solution of such problems.
Źródło:
Control and Cybernetics; 2001, 30, 2; 227-230
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal design of stationary flow problems by path-following interior-point methods
Autorzy:
Antil, H.
Hoppe, R. H.
Linsenmann, C.
Powiązania:
https://bibliotekanauki.pl/articles/970290.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
shape optimization
Stokes flow problems
path-following interior-point methods
Opis:
We consider the numerical solution of structural optimization problems in CFD where the state variables are supposed to satisfy a linear or nonlinear Stokes system and the design variables are subject to bilateral pointwise constraints. Within a primal-dual setting, we suggest an all-at-once approach based on interior-point methods. The discretization is taken care of by Taylor-Hood elements with respect to a simplicial triangulation of the computational domain. The efficient numerical solution of the discretized problem relies on path-following techniques, namely a continuation method with an adaptive choice of the continuation step size, a long-step path-following algorithm and a nonlinear version of Mehrotra's algorithm. The performance of the suggested methods is documented by several illustrative numerical examples.
Źródło:
Control and Cybernetics; 2008, 37, 4; 771-796
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On singular arcs in nonsmooth optimal control
Autorzy:
Oberle, H. J.
Rosendahl, R.
Powiązania:
https://bibliotekanauki.pl/articles/969559.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
nonsmooth optimal control problems
necessary conditions
singular state subarcs
Zermelo's problem
Opis:
In this paper we consider general optimal control problems (OCP) which are characterized by a nonsmooth ordinary state differential equation. However, we allow only mild types of nonsmoothness. More precisely, we assume that the right-hand side of the state equation is piecewise smooth and that the switching points, which separate these pieces, are determined as points, where a state-and possibly control-dependent (smooth) switching function changes sign. For this kind of optimal control problems necessary optimality conditions are developed. Attention is paid to the situation when the switching function vanishes identically along a nontrivial subarc. Such subarcs, which we call singular state subarcs, are investigated with respect to necessary conditions and to junction conditions. In extension to earlier results of the authors, Oberle and Rosendhal (2006), in this paper nonsmooth OCPs are considered with respect to the order of the switching function. Especially, the case of a zero-order switching function is included and examples of order zero, one and two are treated.
Źródło:
Control and Cybernetics; 2008, 37, 2; 429-450
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solving Markov decision processes by d-graph algorithms
Autorzy:
Kátai, Z.
Powiązania:
https://bibliotekanauki.pl/articles/205688.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
Markov decision processes
dynamic programming
graph representation
graph algorithms
optimization problems
Opis:
Markov decision processes (MDPs) provide a mathematical model for sequential decisionmaking (sMDP/dMDP: stochastic/ deterministic MDP). We introduce the concept of generalized dMDP (g-dMDP) where each action may result in more than one next (parallel or clone) state. The common tools to represent dMDPs are digraphs, but these are inadequate for sMDPs and g-dMDPs. We introduce d-graphs as general tools to represent all the above mentioned processes (stationary versions). We also present a combined d-graph algorithm that implements dynamic programming strategies to find optimal policies for the finite/infinite horizon versions of these Markov processes. (The preliminary version of this paper was presented at the Conference MACRo 2011.)
Źródło:
Control and Cybernetics; 2012, 41, 3; 577-593
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-order long-step methods for solving semidefinite linear complementarity problems
Autorzy:
Preiss, M.
Stoer, J.
Powiązania:
https://bibliotekanauki.pl/articles/1839179.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
semidefinite linear complementarity problems
infeasible-interior-point methods
long-step methods
Opis:
The authors studied in Preiss and Stoer (2003) the analyticity properties of infeasible-interior-point paths encountered in the context of semidefinite linear complementarity problems. It will be shown that these results allow for the design of infeasible-interior-point methods of long-step type with an arbitrarily high order of local convergence for solving such problems.
Źródło:
Control and Cybernetics; 2003, 32, 3; 659-670
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability analysis of variational inequalities for bang-singular-bang controls
Autorzy:
Felgenhauer, U.
Powiązania:
https://bibliotekanauki.pl/articles/206215.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
parametric optimal control problems bang-singular control structure
approximation of extremals
Opis:
The paper is related to parameter dependent optimal control problems for control-affine systems. The case of scalar reference control with bang-singular-bang structure is considered. The analysis starts from a variational inequality (VI) formulation of Pontryagin’s Maximum Principle. In a first step, under appropriate higher-order sufficient optimality conditions, the existence of solutions for the linearized problem (LVI) is proven. In a second step, for a certain class of right-hand side perturbation, it is show that the controls from LVI have bang-singular-bang structure and, in L1 topology, depend Lipschitz continuously on the data. Applying finally a common fixed-point approach to VI, the results are brought together to obtain existence and structural stability results for extremals of the original control problem under parameter perturbation.
Źródło:
Control and Cybernetics; 2013, 42, 3; 557-592
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topological derivative for optimal control problems
Autorzy:
Sokołowski, J.
Żochowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/206790.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
sterowanie optymalne
asymptotic expansion
control problems
shape derivative
shape optimization
topological derivative
Opis:
The topological derivative is introduced for the extremal values of cost functionals for control problems. The optimal control problem considered in the paper is defined for the elliptic equation which models the deflection of an elastic membrane. The derivative measures the sensitivity of the optimal value of the cost with respect to changes in topology. A change in topology means removing a small ball from the interior of the domain of integration. The topological derivative can be used for obtaining the numerical solutions of the shape optimization problems.
Źródło:
Control and Cybernetics; 1999, 28, 3; 611-625
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the robustness of the topological derivative for Helmholtz problems and applications
Autorzy:
Leugering, Günter
Novotny, Antonio André
Sokolowski, Jan
Powiązania:
https://bibliotekanauki.pl/articles/2183490.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
topological derivative
shape optimization
inverse problems
Helmholtz problem
numerical methods
complex variables
Opis:
We consider Helmholtz problems in two and three dimensions. The topological sensitivity of a given cost function J(uɛ) with respect to a small hole Bɛ around a given point x0ɛ ∈ Bɛ ⊂ Ω depends on various parameters, like the frequency k chosen or certain material parameters or even the shape parameters of the hole Bɛ. These parameters are either deliberately chosen in a certain range, as, e.g., the frequencies, or are known only up to some bounds. The problem arises as to whether one can obtain a uniform design using the topological gradient. We show that for 2-d and 3-d Helmholtz problems such a robust design is achievable.
Źródło:
Control and Cybernetics; 2022, 51, 2; 227--248
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł

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