No. 123 (2022)

The problems related to advancements in signal processing, mathematical tools and new analysis methods applied in investigations into different industrial fields have been intensively explored over the last few years. This issue at the Scientific Journal of Gdynia Maritime University is addressed to widely-treated problems occurring in a newly-defined discipline of science: automation, electronic and electrical engineering. The issue comprises seven research papers, specifically dedicated to a subject as a developed station for receiving satellite signals in the K band (1), the simulation techniques through which a H1 31.25 kbps Foundation Fieldbus Manchester Coded signal can be modulated or demodulated (2), proposals for solving the question of how to calculate the effective value of voltage V if the energy transfer time Δt is less than the period of the function, T (3), the impact of voltage fluctuations in the current of a one-phase induction motor (4), some calculations of the electrical and magnetic field distributions near the high voltage lines (5) and (6), the multi-criteria analysis of selected strategies for energy management in smart home systems (7).
The first paper (1) presents a developed station for receiving signals in the K band, with particular emphasis on the design and alignment of the antenna in the cassegrain system.
The second paper (2) deals with an analysis of the simulation results dedicated to a Manchester coded signal, which describes the mechanisms through which distortion induced by additive white Gaussian noise can be eliminated during the demodulation process, either by using recursive filters such as a Kalman filter or by calculating wave energy levels in specific time intervals.
In the third paper (3), some remarks on the energy transfer analyses during a time less than period T for voltage and current waveforms in electrical circuits are formulated, mainly in the context of how to calculate an effective value for voltage V under the aforementioned conditions in power electronics circuits.
The fourth paper (4) addresses the theme of a single-phase induction motor under voltage fluctuations while the results of empirical investigations are presented for sinusoidal amplitude modulation of various frequencies and are then compared with the effect of voltage subharmonics occurring as single power quality disturbances.

Papers (5) and (6) address the specific fields of distribution near high voltage lines adequately: paper (5) concerns the calculations for electrical field distribution and the consequences resulting from that, while paper (6) presents similar issues in relation to magnetic field distribution.
The last paper, (7), is dedicated to the problems of selected strategies for energy management in smart home systems, focusing on multi-criteria analysis as a tool for solving the energy management problem in KNX SMART HOME systems, based on two different strategies applied to two model houses.
This issue of the Scientific Journal of Gdynia Maritime University is dedicated to the memory of our long-time associate, Prof. Marian Pasko from the Silesian University of Technology.
Janusz Mindykowski