The effect of wind generator on sub-synchronous resonance (SSR) is being interested by increasing penetration of wind turbine in power systems,. Purpose of this article is to analyze SSR in a wind farm based on doubly fed induction generator (DFIG) which is connected to compensating series grid. A dynamic model for analysis of induction generator effect and Torsional Interaction (TI) has been u...

In the present we introduce a concept of doubly stochastic quadratic operator. We prove necessary and sufficient conditions for doubly stochasticity of operator. Besides, we prove that the set of all doubly stochastic operators forms convex polytope. Finally, we study analogue of Birkhoff’s theorem for the class of doubly stochastic operators. Mathematics Subject Classification: 15A51, 15A63, 4...

Let {Xk, k ≥ 1} be a sequence of independent, identically distributed nonnegative random variables with common distribution function F and finite expectation μ > 0. Under the assumption that the tail probability F(x) = 1−F(x) is consistently varying as x tends to infinity, this paper investigates precise large deviations for both the partial sums Sn and the random sums SN(t), where N(·) is a co...

in recent years, the number of research works devoted to applying the highly accurate numerical schemes, in particular compact finite difference schemes, to numerical simulation of complex flow fields with multi-scale structures, is increasing. the use of compact finite-difference schemes are the simple and powerful ways to reach the objectives of high accuracy and low computational cost. compa...

We investigate manifolds obtained as a quotient of a doubly warped product. We show that they are always covered by the product of two suitable leaves. This allows us to prove, under regularity hypothesis, that these manifolds are a doubly warped product up to a zero measure subset formed by an union of leaves. We also obtain a necessary and sufficient condition which ensures the decomposition ...

Let ; and n be point processes and let p€[O,I]. We say that ; is a p-thinning of n, if it is obtained from n by deleting the atoms independently with probability l-p. It is shown that, if PI,P2, ... €(O,I] with P +0 n and if ; n is a p -thinning of some n for each n€N, then ~n converges in distribution in the vague topology if and only if Pnnn does. Furthermore, denoting the limits by ~ and n r...

The distributed averaging problem is to devise a protocol which will enable the members of a group of n > 1 agents to asymptotically determine in a decentralized manner, the average of the initial values of their scalar agreement variables. A typical averaging protocol can be modeled by a linear iterative equation whose update matrices are doubly stochastic. Building on the ideas proposed in [1...

We introduce a constructive method, by using a doubly stochastic measure, to describe all the copulas that, in view of Sklar’s Theorem, are able to connect a bivariate distribution to its marginals. We use this to give the lower and upper optimal bounds for all the copulas that extend a given subcopula.