This work investigates the performances of several State-Dependent Riccati Equation algorithms for the estimation and control of attitude and attitude rates of a rigid-body spacecraft. The estimators are designed to process line-of-sight and gyros measurements corrupted by white noises and potentially drifting biases. The case of gyroless estimation is also addressed. The vector measurements ar...

In this paper we present an approach for a mobile robot to avoid obstacles by using a stereo-camera system mounted on it. We use the “census transformation” to generate the features for the correspondence search. We train two SNoW (Spare Network of Winnovs)-classifiers, one for the decision wether to move straight forward or to evade and a second one for deciding whether to turn left or right w...

We consider the Cauchy problem of 2 dimensional incompressible Euler equations. We study the problem of growth rate of high Sobolev norms of the solutions. A well-known result that is implicit in [J. T. Beals ,T. Kato and A. Majda, Comm. Math. Phys. 94 (1984), 61-66] is the double exponential rate. An open question that has been asked by Tao is wether we can get an exponential rate. In this pap...

One of the problems of documenting software evolution appears with the extensive use of refactorings. This paper explores a method, based on graph transformation, to detect wether the evolution between two versions of a software system can be expressed by means of a sequence of refactoring operations. For this purpose we extend a graph representation format to use it for simple Java programs, a...

The operation of base contraction was successfully characterized for a very general class of logics using the notion of remainder sets. Although, in the general case, this notion is inadequate for revision, where it is replaced by maximal consistent subsets. A natural question is wether this latter notion allows for a definition of contractionlike operators and, in case it does, what difference...

In this paper, we construct a model of cyber-weapon deployment and attempt to determine an optimal deployment time for cyberweapons using this model. We compare and contrast our approach to that in Axelrod and Iliev (R. Axelrod and R. Iliev. Timing of cyber conflict. Proceedings of the National Academy of Science, (1322638111), 2013.), showing that our model accurately captures four real-world ...

This paper considers the problem of planning collision-free motion of three disks in the plane. One of the three disks, the robot, can autonomously translate in the plane, the other two move only when in contact with the robot. This represents the abstract formulation of a manipulation planning problem. Despite the simplicity of the formulation, the decidability of the problem had remained unpr...

We investigate critical properties of the phase transition in the four-dimensional compact U(1) lattice gauge theory supplemented by a monopole term for values of the monopole coupling λ such that the transition is of second order. It has been previously shown that at λ = 0.9 the critical exponent is already characteristic of a second-order transition and that it is different from the one of th...

This thesis is devoted to the study of subshifts, or symbolic dynamical systems, defined on some finitely presented monoids like Zd or the infinite binary tree. The main result concerning multidimensional subshifts establishes that any effective subshift of dimension d can be obtained by factor map and projective subaction of a subshift of finite type of dimension d+ 1. This result has many app...