Dear Readers, I am pleased to announce the publication of the third edition (63(135)) of the Scientific Journals of the Maritime University of Szczecin in 2020. This edition contains the findings and opinions of the authors within thirteen articles, which are grouped into six fields: Civil Engineering and Transport, Environmental Engineering, Mining and Energy, Electrical Engineering, Mechanical Engineering, Economics, Management and Quality Science, and Information and Communication Technology. The Civil Engineering and Transport section begins with an article in which the authors provide an FMECA for a thermal deburring machine of a Slovak company to develop an efficient maintenance policy. The second article also covers maintenance issues by addressing freight cars used in railway transport. The authors used railroad car operation, maintenance, and failure data to establish a methodology to calculate the probability of failure and thereby determine the risk levels in the rolling stock maintenance policy. The author of the third article noted that the continued growth of transport systems and the extensive activities related to the system user safety require the development of methods to assess how the extension or upgrading of road infrastructure impacts road safety. The author aimed to develop an assessment concept that will form part of a comprehensive methodology for analyzing the operational reliability of transport systems. Conceptualized in the article is an assessment of the impact of road infrastructure on road safety that refers to the GAMAB and Road Safety Impact Assessment methods reported in the literature. The concept is based on a comparative analysis of the state of road infrastructure before and after expansion or upgrades, based on publicly-available data. The last article in this section deals with digitization, one of the most urgent modern determinants of economic activity. The authors consider the digitization of transport as a tool for achieving the European Union’s policy objectives set out in the Digital Single Market Strategy for Europe. For railway transport, digital innovation is necessary to increase its competitiveness, and one of the tools for the digital transformation of the railway is the fifth-generation of wireless communication systems (5G). The purpose of this article is to show the advantages of 5G deployment for railway operators. It describes unique flexibility in the allocation of 5G network resources, depending on the existing needs of rail traffic. The Environmental Engineering, Mining and Energy section contains study, that elaborates on the modern technologies used for the production and utilization of methanol. Particular attention was paid to technology for energy storage in the form of “renewable” methanol generated from hydrogen produced using renewable surplus energy or from captured CO2. The paper presents a methanol production and treatment plant and a methodology for assessing the plant efficiency. The Electrical Engineering section contains two studies. The first article demonstrates that an electricity- and-power system is affected by various types of power quality disturbances, which have a detrimental effect on generators, transformers and electrical appliances. At the same time, the authors noted that some 6 Scientific Journals of the Maritime University of Szczecin 63 (135) of the most harmful disturbances in power quality are voltage subharmonics, and the study describes the effect of voltage subharmonics on power losses and the heating-up of an induction motor. The second article presents methods for analyzing the power characteristics of generator sets with vector control of an asynchronous squirrel-cage machine. These methods facilitate analyses of the power characteristics of generator sets with field-oriented control (FOC) and direct torque control (DTC). The Mechanical Engineering section also contains two studies. The authors of the first article presented an analysis of possible variants of a handling terminal system by considering the factors of the current development of the Russian transport system. Their considerations were directed at identifying the rationale and possible issues related to the lack of human presence in the technological process of an inland container terminal. The control system of a mini crane is reported in the second study of this section, which analyses a system employing a programmable logic-controlled exoskeleton. The Economics, Management and Quality Science section presents three articles. The first examines the impact of exchange rate movements on international trade. The authors point out that various studies prove that the impact may vary between different sectors and countries. In the fishing industry, this relationship was not widely studied; therefore, an analysis was undertaken in this respect. Using the Emirmahmutoğlu and Köse causality test, the authors examined whether exchange rate fluctuations in certain countries affected fish production. The authors of the next study considered the most important problem in recent months, COVID-19. As we have already seen, the pandemic is a strong determinant, not only of social life, but the economy as well. Recognizing the strong impact of COVID-19 on different spheres of our lives, the authors analyzed the impact of the coronavirus pandemic on the oil market. The authors of the third study in this section, assuming that the management process analysis allows the detection of weaknesses and strengths, analyzed the production line management processes. To this end, they created a queuing model for a production line and analyzed its performance and reliability. The attempted modelling was used to determine whether queuing theory can be used to mod-el processes in production lines. In the last section, Information and Communication Technology, the authors evaluated the tracking performance of the GOOSE platform and compared it to a reference receiver. The quality and performance were analyzed using raw measurements of three signals, GPS L1CA, L2CM and L5. The data were processed with the “zeroEdit” module of the TUB-NavSolutions software. In conclusion, the presented articles address a wide range of contemporary problems that can initiate theoretical and empirical scientific research. We are aware that the problems are described only to a modest extent, yet we hope that the articles will inspire further research and considerations.

The GOOSE (GNSS Receiver with open software interface) Software-Defined Receiver has been developed at the Fraunhofer Institute for Integrated Circuits (IIS) in Nürnberg, Germany. The main motivation for the development of this platform was to control the receiver at all stages, from digital signal processing to the PVT domain, and to enable controlled feedback to the hardware. Besides having access to all raw data including correlation values, the GOOSE receiver also enables for example tight- or ultra-tight integration with an inertial navigation system or other dead reckoning systems, as these kinds of architectures require access to the acquisition and tracking loops. In this paper, the tracking performance of the GOOSE platform was evaluated and compared to a reference receiver (Septentrio PolaRx5S). Several long data sessions were recorded on a “zero baseline” in which both receivers used the same precise geodetic antenna that was also developed at Fraunhofer IIS. The measurements were performed in a harsh environment (obstructions, multipath, possible interferences), as well as on a site with an unobstructed sky view. Quality and performance analyses were performed using raw measurements (in the domain of primary observables) of three civil GPS signals: L1CA, L2CM, and L5. The data were processed using the “zeroEdit” module of the TUB-NavSolutions academic software for education and research. The quality of the raw observables and tracking performance were described by the following parameters: number of cycle slips detected, number of un-correctable cycle slips, number of loss of locks of the signals, number of single epoch data gaps, and the length of carrier phase arcs. The presentation is illustrated with some numerical examples.

The article presents the analysis of options for a transshipment terminal system with consideration of Russian transport system development. The aim is to determine the premises and possible problems, considering human absence, in the technological process at an inland container terminal. Statistical methods are used to analyze the market of robotic automation and the perspective for unmanned technology introduction. Simulation modeling of inland container terminal operation with various types of equipment, to study the applicability of robotic automation. The choice of modeling equipment results from the impossibility of completing an experiment on the real object, difficulties of analytical modeling (the system contains casual relations, nonlinear logic, stochastic variables), and the necessity to analyze the system’s time behavior. Consideration of robotic automation in a terminal warehouse complex is of particular importance due to technological progress followed by the freight terminal to be an area with highly organized technological processes and the need for highly paid specialists.

This paper deals with the effect of voltage subharmonics on power losses and heating of an induction motor. An increase in power losses in stator and rotor windings and their impact on windings temperature is presented for subharmonics of various frequencies. The results of this study’s investigations are provided for subharmonics occurring as a single power quality disturbance and combined with voltage deviation. The appropriate electromagnetic computations were performed with the finite element method, and thermal ones – with an analytical method.

The paper presents technologies currently being developed for methanol production and its applications. Particular attention was paid to energy storage technology in the form of “renewable” methanol, which is produced from hydrogen generated from surplus energy from renewable energy sources and from captured CO2. The global methanol market was characterized, i.e. global demand, major producers and global demand for products made from methanol. The installation of methanol production and purification with stoichiometry as well as the methodology for assessing the efficiency of such an installation are also presented. The results of the analysis of such an installation were discussed in accordance with the methodology given.

At the beginning of the COVID-19 coronavirus global pandemic, the oil market was crushed. In this period, the oil market was correlated with COVID-19 coronavirus world infection cases: more infected cases resulted in low oil prices, and the negative correlation between these two indices was very strong. Different factors determined the increase in both crude oil price and the number of oil futures contracts after April 20. Firstly, oil prices were driven by the coronavirus mortality rate, rather than by the absolute number of infection cases. The decisive driver for oil prices in the medium-term became pandemic development trends, instead of the actual epidemiological situation. This statement is proven by the statistical regression model of the interdependence between oil prices and COVID-19 coronavirus world mortality rate. Secondly, a gradual stable decrease in the coronavirus world mortality rate created an environment for the gradual restart of the world economy. Thirdly, the coronavirus mortality rate analysis provides investors with tangible guidelines to assess the medium-term sustainability of futures markets and, therefore, to elaborate investment strategies. Fourthly, after April 20, the oil market gradually achieved equilibrium, which is proven by a restored correlation between oil prices and the Euro-to-U.S. Dollar exchange rate. Three-month tendencies provide tangible guidelines for an optimistic forecast of the oil the market and maritime tanker business for the end of 2020 and all of 2021. So long as a new wave of COVID-19 does not dramatically increase mortality rates, the oil and maritime tanker trade market will regain the equilibrium it lost at the end of January.

This study proposes a new methodology for the accurate risk assessment of railway freight wagons that has real-world applications in the operation and maintenance of freight vehicles. The paper specifically focuses on the analysis of posterior reliability calculation methods using Weibull’s reliability model to calculate reliability indicators by which the probability of occurrence of individual failures can be estimated. The consequences of failure are calculated through an existing system from the General contract used for freight wagons (AVV). The formula for calculating the risk value is based on a classical risk theory, where the risk is defined as a combination of the occurrence of a negative phenomenon and the severity of its consequence. The reasoning for this approach was in an effort to maintain simplicity and clarity for potential users in practice. This is based on the information gathered in examining the current state of risk management in the sector of railway vehicles in Slovakia. The data used for risk calculations were taken from a maintenance workshop in Slovakia to provide a realistic picture of the failure rates of freight wagons. The proposed methodology uses historical data for prediction of reliability for the next years. Based on the reliability being a function of time, the risk associated with it is variable, increasing with time. These findings have broader implications for the maintenance systems taken appropriate maintenance actions necessary with respect to increased risk.

The constant development of transport systems and the extensive activities related to the safety of its users necessitate the development of methods for assessing the impact of road infrastructure expansion/modernization on road safety. The objective of this paper is to elaborate the concept of such an assessment, which will form part of the author’s activities aimed at creating a methodology for a comprehensive analysis of the operational reliability of transport systems. The concept of assessing the impact of road infrastructure development on road safety presented in this paper refers to the GAMAB and Road Safety Impact Assessment methods from the subject literature. Our method is based on a comparative analysis of the condition of road infrastructure before and following its expansion/modernization, based on commonly available data, which constitutes the main advantage of the concept presented in this paper. Furthermore, the coefficients for occurrence of adverse road events were determined, and then conclusions drawn on this basis. The acquired results constitute an argument for the correctness of the presented concept.

This study investigates FMECA analysis and its potential use in improving the reliability and maintenance of the thermal deburring machine in a manufacturing company located in Slovakia. In the beginning, an overview of the FMEA/FMECA methods and their utilization for increased reliability are discussed. As a practical solution, the deburring machine EXTRUDE HONE TEM P-350 was chosen. Functions of its systems and components, thermal deburring process, its characteristics and in practice application are described. Maintenance policy in the company and the current state of maintenance of the machine are also presented. In addition, the study includes failure analysis which evaluates the riskiest systems of the machine. One element, hydraulic unit, is a subject for the FMECA analysis which envisions the assessment of the current failure modes using risk priority number (RPN) and proposals of prevention and detection action reducing the level of RPN. The final section focuses on influencing and improving maintenance and summarizing the potential benefits of FMECA Analysis for company and machine operation.

Digitisation of transport is a tool for achieving the European Union’s political goals included in the Digital Single Market Strategy for Europe. For rail transport, digital innovation is required to increase its competitiveness. One of the tools of the digital transformation of railways is 5G networks, the fifth generation of wireless communication systems. The purpose of this article is to present the benefits of implementing 5G network for railway operators. Focus was placed on its innovative features, such as ultra-fast access to Internet services, very high connection reliability, and extremely low data transmission delays. Examples of new services for railway operators based on the capabilities of 5G networks were presented. This article describes the unique functions of the 5G network in which resources can be flexibly allocated depending on current traffic needs thanks to the network slicing function, e.g., for services of key importance to rail traffic and commercial services for other market segments. Roadmap proposals for transforming the current rail communication network infrastructure towards the target FRMCS system are presented. The analysis was based on source materials from Nokia Corporation, available literature, EU documents and regulations, as well as institutional studies of the railway sector.

One of the most important factors affecting international trade is exchange rate fluctuations. To date, studies that have analyzed the effect of exchange rates have shown that the effect can vary from sector to sector and from country to country. The fact that this relationship has not been extensively studied in the fisheries industry is the motivation for this study. In this regard, the aim of this study is to determine whether changes in the real exchange rates of countries affect their fisheries production levels. Accordingly, we used the causality test developed by Emirmahmutoglu and Kose (2011), which takes into account both cross-sectional dependencies and heterogeneity. The data set used in this study consisted of 27 annual observations from 38 countries from 1990–2016. The results revealed that changes in the real exchange rate affected fisheries production. This situation shows that changes in exchange rates may affect the international demand for fisheries and serve as a source of motivation for producers.

Analytical research methods to determine the power characteristics of generator sets with vector control in an asynchronous squirrel-cage machine were developed and used to calculate the energy characteristics of generator sets with the field-oriented control (FOC) and direct torque control (DTC). The analytical calculations showed that a generator set with direct torque control had slightly better energy characteristics. Confirmation of the analytical calculation results was carried out using simulation models developed in the MATLAB-Simulink package with an environment Simscape Power System.

In today’s production and service systems, the management process plays a primary role. Analysis of the management process allows the detection of weaknesses and strengths in analyzed systems. This paper analyses production line management processes. For one literature example, a queuing model of a selected production line was built, and its performance and reliability were analyzed. The modelling attempt undertaken here was designed to determine whether queuing theory is suitable for modelling production line processes. Confirmation of this thesis would be a novelty in this field.

In this paper, a mini-crane control system using an exoskeleton based on programmable logic technology is presented. The first stage was to identify the parameters of the mini-crane and exoskeleton sub-assemblies. Then, individual crane and exoskeleton control subsystems were designed based on cascade regulation. The final stage was to connect these subsystems into the master-slave control system using the manipulator’s kinematics equations. Parallel processing was used to minimize delays in the control system. Analysis of the results showed that the difference between the set and measured crane position was small.