We consider the partial observability model for multi-armed bandits, introduced by Mannor and Shamir [11]. Our main result is a characterization of regret in the directed observability model in terms of the dominating and independence numbers of the observability graph. We also show that in the undirected case, the learner can achieve optimal regret without even accessing the observability grap...

Several concepts on the measure of observability, reachability, and robustness are defined and illustrated for both linear and nonlinear control systems. Defined by using computational dynamic optimization, these concepts are applicable to a wide spectrum of problems. Some questions addressed include the observability based on userinformation, the determination of strong observability vs. weak ...

Infinite–dimensional linear dynamic systems, with output, are studied. They are described by row-finite infinite matrices. Observability of such systems is investigated. It is shown that observability is equivalent to the property that one can calculate the value of each state variable using only finitely many rows of Kalman observability matrix. Different necessary or sufficient conditions of ...

Reachability and observability criteria are obtained for 2D continuous-discrete time-variable Attasi type systems by using suitable 2D reachability and observability Gramians. Necessary and sufficient conditions of reachability and observability are derived for time-invariant systems. The duality between the two concepts is emphasized as well as their connection with the minimality of these sys...

Positive reachability and positive observability of positive linear systems on time scales are studied. Differential and integral calculus on time scales allows for unified treatment of continuousand discrete-time systems. Reachability and observability graphs for positive systems are introduced. They are used to characterize positive reachability and positive observability for systems on homog...

Stochastic observability refers to the existence of a filter for which the errors of the estimated state mean vector have bounded variance. In this paper, we derive a test to assess the stochastic observability of a Kalman filter implemented for discrete linear time-varying stochastic systems. This test is derived with the assumptions that the system matrices consist of known, deterministic par...

In this paper, we study the observability properties of nonlinear discrete time systems. Two types of contributions are given. First, we present observability criteria in terms of appropriate codistributions. For particular, but significant, classes of systems we provide criteria that require only a finite number of computations. Then, we consider invertible systems (which includes discrete-tim...

In this paper, we consider local observability at an initial state for discrete-time autonomous polynomial systems. When testing for observability, for discrete-time nonlinear systems, a condition based on the inverse function theorem is commonly used. However, it is a sufficient condition. In this paper, first we derive a necessary and sufficient condition for global observability at an initia...

We study observability of switched differentialalgebraic equations (DAEs) for arbitrary switching. We present a characterization of observability and, a related property called, determinability. These characterizations utilize the results for the single-switch case recently obtained by the authors. Furthermore, we study observability conditions when only the mode sequence of the switching signa...

A class of multidimensional hybrid linear systems is presented, with the time vector composed by q continuous-time real components and by r discrete-time integer ones, q, r ≥ 1. The state equation is of multidimensional partial differential-difference type. A generalized variation-of-parameters formula is provided and it is used to obtain the state and the general response of the system. The fu...