We examine the variance of the number of eigenvalues of the Laplacian for the modular surface in a short interval. The analysis allows for the interval to be small enough so that the size of the variance is Poissonian. The starting point for the investigation is the Kuznetsov formula and the body of the work consists of studying the complicated off-diagonal contributions which are responsible f...

In this paper, a direct power control (DPC) strategies have been investigated in order to control a high power AC/DC converter with time variable load. This converter is composed of a three level three phase neutral point clamped (NPC) converter as rectifier and an H-bridge four quadrant current control converter. In the high power application, controller not only must adjust the desire outputs...

for beneficiation of converter slag, the role of surface phenomena on slag composition was studied. this work includes some experimental data, which were measured for basic oxygen steel (bos) slag in isfahan steel plant. all data were collected on site in the plant. the results support the idea that surface activity plays a major role in converter slag formation. it was also a new finding that ...

This paper presents the hybrid seven-level cascaded active neutral-point-clamped (ANPC)-based multilevel converter. The converter topology is the cascaded connection of a three-level ANPC converter and an H-bridge per phase. The proposed topology provides a tradeoff between different component counts to achieve a good loss distribution, avoid direct series connection of semiconductor devices, k...