Due to their ability to synthesize waveforms with better harmonic spectrum and attain higher voltages, multi-level inverters are receiving increasing attention in the past few years. The multilevel inverter was introduced as a solution to increase the converter operating voltage above the voltage limits of classical semiconductors. In this paper, a Diode Clamped Multilevel Inverter is controlle...

this paper presents a new control methodology for active power filters that provide an adaptive online harmonic estimation with partial and selective harmonic reduction schemes, which has been implemented within an integrated controller. the proposed approach is to provide partial and selective reduction of those individual harmonics which exceed the recommended levels as set by regulatory bodi...

one of the important factors influencing outdoor insulators performance is pollution phenomenon. the pollution, especially during humidity condition, reduces superficial resistance of insulator and lead to a flow of leakage currents (lc) on the insulator surface, which may result in total flashover. the lc characteristics are affected by parameters such as nature and severity of pollution. loca...

in order to study stress tolerance indices and identifying tolerance genotypes to drought stress condition 16 genotypes of durum wheat were assessed in a randomized complete block design with four replications under two irrigated and rainfed conditions in the research station located in west of iran ilam in 2006- 2007. results showed that variation in among durum wheat genotypes under irrigated...

We have developed a diode-pumped Nd:YVO4 cw laser for testing KTiOPO4 crystals designed for intracavity second-harmonic generation at 532 nm. We demonstrate that this source is extremely sensitive to defects inside the crystal, inducing losses at 1064 nm and an index mismatch between fundamental and harmonic waves.

Harmonic sliding analysis (HSA) is a dynamic spectrum analysis [1] in which the next analysis interval differs from the previous one by including the next signal sample and excluding the first one from the previous analysis interval. Such a harmonic analysis is necessary for time-frequency localization [2] of analysed signal given peculiarities. Using the well-known Fast Fourier transform (FFT)...

The harmonic index H(G) of a graph G is the sum of 2 d(u) + d(υ) over all edges uυ of G, where d(u) denotes the degree of a vertex u in G. In this paper, we give the minimum value of H(G) for graphs G with given minimum degree δ(G) ≥ 2 and characterize the corresponding extremal graph. Furthermore, we prove a best-possible lower bound on the harmonic index of a triangle-free graph G with arbitr...

We study properties of the harmonic measure of balls in large critical Galton–Watson trees whose offspring distribution is in the domain of attraction of a stable distribution with index α ∈ (1, 2]. Here the harmonic measure refers to the hitting distribution of height n by simple random walk on the critical Galton–Watson tree conditioned on non-extinction at generation n. For a ball of radius ...