On application of least-delay variation problem in ethernet networks using SDN concept

The goal of this paper is to present an application idea of SDN in Smart Grids, particularly, in the area of L2 multicast as defined by IEC 61850-9-2. Authors propose an Integer Linear Formulation (ILP) dealing with a Least-Delay-Variation multicast forwarding problem that has a potential to utilize Ethernet networks in a new way. The proposed ILP formulation is numerically evaluated on random graph topologies and results are compared to a shortest path tree approach that is traditionally a product of Spanning Tree Protocols. Results confirm the correctness of the ILP formulation and illustrate dependency of a solution quality on the selected graph models, especially, in a case of scale-free topologies

Analysis of microstrip antennas

Práce pojednává o numerické metodě pro analýzu jednoportových mikropáskových obvodů, která se nazývá metoda hraničních prvků. Je zde popsán obecný postup výpočtů důležitých parametrů pro analýzu mikropáskových antén. Dále jsou numericky řešeny geometrické parametry nutné pro vyčíslení prvků matic U a H, pomocí nichž lze jednoduše získat vstupní impedanci obvodu nebo činitel odrazu na vstupu obvodu.This work deals with the method for analysis of one-port microstrip circuits which is called as contour-integral method. The general procedure for evaluating of important parameters concerning the analysis of microstrip antennas is given. Next, the geometrical parameters necessary for the calculation of elements in U and H matrices are numerically solved. With the help of these matrices, the input impedance or the reflection coefficient can be easily found.