this paper presents a new control method for a three-phase four-wire unified power quality conditioner (upqc) to deal with the problems of power quality under distortional and unbalanced load conditions. the proposed control approach is the combination of instantaneous power theory and synchronous reference frame (srf) theory which is optimized by using a self-tuning filter (stf) and without us...

‎We consider the oscillator group equipped with‎ ‎a biinvariant Lorentzian metric‎. ‎Some geometrical properties of this space and the harmonicity properties of left-invariant vector fields on this space are determined‎. ‎In some cases‎, ‎all these vector fields are critical points for the energy functional‎ ‎restricted to vector fields‎. ‎Left-invariant vector fields defining harmonic maps are...

We study non-Gaussianity induced by a pseudo Nambu-Goldstone boson with a cosine-type scalar potential. We focus on how the non-Gaussianity is affected when the pseudo Nambu-Goldstone boson rolls down from near the top of the scalar potential where the deviation from a quadratic potential is large. We find that the resultant non-Gaussianity is similar to that obtained in the quadratic potential...

The paper is devoted to the solution of the inverse boundary problem for the heat equation. Let Ω be a connected bounded domain in R n (n ≥ 2) with C l (l ≥ 2) boundary Γ. Consider the mixed problem for the heat equation (1.1)        (ρ(x)∂ t − −)u f (t, x) = 0 in (0, +∞) × Ω, u f (t, x) = f (t, x) o n(0 , +∞) × Γ, u f (0, x) = 0 on Ω. The density ρ(x) is a C l+σ , 0 < σ < 1, function on...

In the present paper, we study uniform approximation of bounded functions on an open subset of the Euclidean space d by means of harmonic functions arising as solutions of the classical or generalized Dirichlet problem. As a consequence of results obtained we establish a harmonic analogue of Sarason’s H + C – theorem; see e. g. [5]. We shall consider an arbitrary bounded open subset of , d ≥ 2....

Traveling Wave Tubes (TWTs) consist of different elements. The most important element of TWT is the RF circuit. RF circuits in helix TWTs need a dielectric support to hold the helix; this support also has an effect in electromagnetic properties of RF circuits. A novel dielectric support is proposed to reduce the second harmonic of helix TWTs. The dielectric support in this structure consists of...

A model of auditory grouping is described in which auditory attention plays a key role. The model is based upon an oscillatory correlation framework, in which neural oscillators representing a single perceptual stream are synchronised, and are desynchronised from oscillators representing other streams. The model suggests a mechanism by which attention can be directed to the high or low tones in...

The paper is devoted to the solution of the inverse boundary problem for the heat equation. Let Ω be a connected bounded domain in R n (n ≥ 2) with C l (l ≥ 2) boundary Γ. Consider the mixed problem for the heat equation (1.1)        (ρ(x)∂ t − −)u f (t, x) = 0 in (0, +∞) × Ω, u f (t, x) = f (t, x) o n(0 , +∞) × Γ, u f (0, x) = 0 on Ω. The density ρ(x) is a C l+σ , 0 < σ < 1, function on...