12 results match your criteria: "St. Petersburg State Marine Technical University[Affiliation]"
Comput Methods Biomech Biomed Engin
June 2024
School of Automation, Hangzhou Dianzi University, Hangzhou, China.
Motor imagery (MI) stands as a powerful paradigm within Brain-Computer Interface (BCI) research due to its ability to induce changes in brain rhythms detectable through common spatial patterns (CSP). However, the raw feature sets captured often contain redundant and invalid information, potentially hindering CSP performance. Methodology-wise, we propose the Information Fusion for Optimizing Temporal-Frequency Combination Pattern (IFTFCP) algorithm to enhance raw feature optimization.
View Article and Find Full Text PDFHeliyon
March 2024
Wolfson Centre for Magnetics, School of Engineering, Cardiff University, Cardiff, CF24 3AA, UK.
In a world grappling with escalating energy demand and pressing environmental concerns, microgrids have risen as a promising solution to bolster energy efficiency, alleviate costs, and mitigate carbon emissions. This article delves into the dynamic realm of microgrids, emphasizing their indispensable role in addressing today's energy needs while navigating the hazards of pollution. Microgrid operations are intricately shaped by a web of constraints, categorized into two essential domains: those inherent to the microgrid itself and those dictated by the external environment.
View Article and Find Full Text PDFJ Neurosci Methods
May 2024
School of Automation, Hangzhou Dianzi University, Hangzhou 310018, China.
Background: Cortico-muscular coherence (CMC) between the cerebral cortex and muscle activity is an effective tool for studying neural communication in the motor control system. To accurately evaluate the coherence between electroencephalogram (EEG) and electromyogram (EMG) signals, it is necessary to accurately calculate the time delay between physiological signals to ensure signal synchronization.
New Method: We proposed a new delay estimation method, named wavelet coherence time lag (WCTL) and the significant increase areas (SIA) index as a measure of the specific region enhancement effect of the magnitude squared coherence (MSC) image.
Heliyon
August 2022
St. Petersburg State Marine Technical University, 190121, St. Petersburg, Russia.
The necessity to improve the metallographic analysis systems to automate diagnostics of the condition of the metals for all their characteristics has been substantiated. The metallographic analysis algorithm based on the use of neural networks for recognizing metal microstructures and a case-based reasoning approach for determining the metal grade is proposed. The structure of a multilayer neural network to determine the metals quantitative parameters has been developed.
View Article and Find Full Text PDFMaterials (Basel)
December 2021
National Research Center "Kurchatov Institute", Akademika Kurchatova 1, 123182 Moscow, Russia.
The present work seeks to extend the level of understanding of the stress field evolution during direct laser deposition (DLD) of a 3.2 mm thick multilayer wall of Ti-6Al-4V alloy by theoretical and experimental studies. The process conditions were close to the conditions used to produce large-sized structures by the DLD method, resulting in specimens having the same thermal history.
View Article and Find Full Text PDFMaterials (Basel)
December 2021
World-Class Research Center Advanced Digital Technologies, St. Petersburg State Marine Technical University, St. Petersburg 190121, Russia.
The results disclosed that both the microstructure and mechanical properties of AA7075-T6 laser welds are considerably influenced by the heat input. In comparison with high heat input (arc welding), a smaller weld fusion zone with a finer dendrite arm spacing, limited loss of alloying elements, less intergranular segregation, and reduced residual tensile stress was obtained using low heat input. This resulted in a lower tendency of porosity and hot cracking, which improved the welded metal's soundness.
View Article and Find Full Text PDFMaterials (Basel)
December 2021
World-Class Research Center "Advanced Digital Technologies", St. Petersburg State Marine Technical University, 190121 St. Petersburg, Russia.
The study of the formation of microstructural features of low-alloy bainite-martensitic steel 09CrNi2MoCu are of particular interest in additive technologies. In this paper, we present a study of cold-rolled samples after direct laser deposition (DLD). We investigated deposited samples after cold plastic deformation with different degrees of deformation compression (50, 60 and 70%) of samples from steel 09CrNi2MoCu.
View Article and Find Full Text PDFMaterials (Basel)
October 2021
World-Class Research Center "Advanced Digital Technologies", St. Petersburg State Marine Technical University, Lotsmanskaya 3, 190121 St. Petersburg, Russia.
In the present work, the mechanical properties of the DLD-processed Ti-6Al-4V alloy were obtained by tensile tests performed at different temperatures, ranging from 20 °C to 800 °C. Thereby, the process conditions were close to the conditions used to produce large-sized structures using the DLD method, resulting in specimens having the same initial martensitic microstructure. According to the obtained stress curves, the yield strength decreases gradually by 40% when the temperature is increased to 500 °C.
View Article and Find Full Text PDFMaterials (Basel)
September 2021
Institute of laser and welding technologies, St. Petersburg State Marine Technical University, 3 Lotsmanskaya, 190121 St. Petersburg, Russia.
In this paper, we present the results of a study on droplet transferring with arc space short circuits during wire-arc additive manufacturing (WAAM GMAW). Experiments were conducted on cladding of single beads with variable welding current and voltage parameters. The obtained oscillograms and video recordings were analyzed in order to compare the time parameters of short circuit and arc burning, the average process peak current, as well as the droplets size.
View Article and Find Full Text PDFEntropy (Basel)
January 2021
Department of Cyber-Physical Systems, St.Petersburg State Marine Technical University, 190121 St. Petersburg, Russia.
An information model is outlined, which represents an intelligent system of metallographic analysis in the form of a set of subsystems, the interaction of which ensures the performance of metallographic analysis functions. The structure of the information storage subsystem for metallographic analysis is presented. The deployment model of an intelligent metallographic analysis system is proposed and described.
View Article and Find Full Text PDFMaterials (Basel)
June 2020
SEC Siberian Center for Industrial Design and Prototyping, National Research Tomsk State University, Tomsk Oblast 634050, Russia.
The urgency of heat treatment of samples of maraging steel obtained by direct laser deposition from steel powder 06Cr15Ni4CuMo is considered. The structural features and properties of 06Cr15Ni4CuMo steel samples after direct laser deposition and heat treatment are studied. The work is devoted to research into the influence of thermal processing on the formation of structure and the mechanical properties of deposit samples.
View Article and Find Full Text PDFJ Acoust Soc Am
April 2009
St Petersburg State Marine Technical University, St Petersburg, Russia.
Propagation of energy along the sound channel axis cannot be formally described in terms of geometrical acoustics due to repeated cusped caustics along the axis. In neighborhoods of these cusped caustics, a very complicated interference pattern is observed. Neighborhoods of interference grow with range and overlap at long ranges.
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