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...

This paper presents a new control method for simultaneous compensation of instantaneous reactive power and current harmonics by parallel active filters (PAFs). Reference compensating currents of PAF are calculated using the subtraction of instantaneous power from its average value. In this way, it is possible omitting high/low pass filter(s) from the control circuit of PAF, which usually result...

The student movement is considered as one of the important issues of Iranian political sociology, but its role and its nature and its relationship with other movements and movements in Iran have been discussed. The present article is trying to answer the role and function of the student movement in Iran. Using a descriptive-analytic approach, political currents have become instrumental in most ...

We construct new topological theories related to sigma models whose target space is a seven dimensional manifold of G2 holonomy. We define a new type of topological twist and identify the BRST operator and the physical states. Unlike the more familiar six dimensional case, our topological model is defined in terms of conformal blocks and not in terms of local operators of the original theory. W...

Nowadays, more than 10,000 different types of medical devices can be found in hospitals.These devices used in medical centers and hospitals for monitoring and treatment of patients require periodic safety and performance checking in order to have confidence in their functioning and operation. Physicians need better accurate medical measurements in order to better diagnose diseases, monitor pati...

It has been known for a long time (Mestel 1953) that the meridional circulation velocity in stars, in the presence of μ-gradients, is the sum of two terms, one due to the classical thermal imbalance (Ω-currents) and the other one due to the induced horizontal μ-gradients (μ-induced currents, or μ-currents in short). In the most general cases, μ-currents are opposite to Ω-currents. Simple expres...