The notion of a U-exact sequence is generalization the exact sequence. In this paper, we introduce rough in group an approximation space. Furthermore, provide properties group.

In this paper, a new circuit is proposed for step-up Z-source inverter based on QZSI (quasi-Z-source inverter). The proposed topology inherits all advantages of the conventional topology. The proposed topology in comparison with conventional topology reduces the ST (Shoot-through) duty cycle by over 25% at the same voltage boost factor. Theoretical analysis of the proposed qZSI in the ST and no...

In this paper, a new topology for cascaded multilevel inverter based on quasi-Z-source converter is proposed. In the proposed topology the magnitude of output DC voltage is not limited to the sum of magnitude of DC voltage sources. Moreover, the reliability of the circuit due to capability of short circuit by Z-source network is increased. The quasi-Z- source converter in different modes is ana...

Due to the favorable performance of structural topology optimization to create a proper understanding in the early stages of design, this issue is taken into consideration from the standpoint of research or industrial application in recent decades. Over the last three decades, several methods have been proposed for topology optimization. One of the methods that has been effectively used in stru...

In this paper a new topology for Dynamic Voltage Restorer (DVR) with high frequency link is proposed. This topology is able to compensate different types of voltage disturbances such as voltage sag, voltage swell and voltage harmonics. According to the obtained equations, this topology operates as a controllable current source to charge the series capacitor. Due to using High Frequency Transfor...

In this paper‎, ‎we introduce a new model of point free topology‎ ‎for point-set topology‎. ‎We study the basic concepts in this‎ ‎structure and will find that it is naturally close to point-set‎ ‎topology‎.‎

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

In this paper, a pointwise pseudo-metric function on the L-realline is constructed. It is proved that the topology induced by this pointwisepseudo-metric is the usual topology.