scholarly journals STABILIZATION OF CONTROLLED DIFFUSIONS AND ZUBOV'S METHOD

2006 ◽  
Vol 06 (03) ◽  
pp. 373-393 ◽  
Author(s):  
FABIO CAMILLI ◽  
ANNALISA CESARONI ◽  
LARS GRÜNE ◽  
FABIAN WIRTH

We consider a controlled stochastic system which is exponentially stabilizable in probability near an attractor. Our aim is to characterize the set of points which can be driven by a suitable control to the attractor with either positive probability or with probability one. This will be done by associating to the stochastic system a suitable control problem and the corresponding Zubov equation. We then show that this approach can be used as a basis for numerical computations of these sets.

Author(s):  
Ari Arapostathis ◽  
Anup Biswas ◽  
Somnath Pradhan

In this article we consider the ergodic risk-sensitive control problem for a large class of multidimensional controlled diffusions on the whole space. We study the minimization and maximization problems under either a blanket stability hypothesis, or a near-monotone assumption on the running cost. We establish the convergence of the policy improvement algorithm for these models. We also present a more general result concerning the region of attraction of the equilibrium of the algorithm.


Author(s):  
Hussain A. El-Saify

Using a previous result by Gali and El-Saify (1983) and the theory of Kotarski (1989), and Lions (1971), we formulate the boundary control problem for a system governed by Neumann problem involving selfadjoint elliptic operator of2ℓth order with an infinite number of variables. The inequalities which characterize the optimal control in terms of the adjoint system are obtained, it is studied in order to construct algorithms attainable to numerical computations for the approximation of the control.


Spine ◽  
1985 ◽  
Vol 10 (1) ◽  
pp. 1-14 ◽  
Author(s):  
RICHARD HERMAN ◽  
JAMES MIXON ◽  
ANNE FISHER ◽  
RUTH MAULUCCI ◽  
JOSEPH STUYCK

2018 ◽  
Vol 7 (3.13) ◽  
pp. 51
Author(s):  
S Kravtsov ◽  
K Rumyantsev

A method for determining the head height of fuel assemblies in the reactor core of a nuclear power unit using a 3-D reconstruction of a stereopair of collinear images is considered. The method is based on the principle of statistical evaluation of the height of a set of points for a 3-D reconstruction of the contour of the head of the fuel assembly. To obtain a stereopair of images, it is suggested to use a collinear digital stereo-vision system. A model experiment was carried out. The results are compared with the known method for determining the height of the heads of fuel assemblies, based on an estimate of the height of the centers of gravity of the contours of fuel assembly heads. The proposed method shows a higher accuracy in solving the problem of determining the heights of fuel assembly heads in comparison with the known method.  


Author(s):  
Pedro R. S. Antunes ◽  
Antoine Henrot

In this paper, we study the set of points in the plane defined by {( x , y )=( λ 1 ( Ω ), λ 2 ( Ω )), | Ω |=1}, where ( λ 1 ( Ω ), λ 2 ( Ω )) are either the first two eigenvalues of the Dirichlet–Laplacian, or the first two non-trivial eigenvalues of the Neumann–Laplacian. We consider the case of general open sets together with the case of convex open domains. We give some qualitative properties of these sets, show some pictures obtained through numerical computations and state several open problems.


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