2021 - Repozytorium publikacji - Politechnika Gdańska

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Selected information technology tools supporting for maintenance and operation management electrical grids
- Waldemar Kamrat
2021 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences
The paper presents the main issues of management of electrical grids. Selected information technology tools supporting for electrical grids maintenance are presented. In electrical infrastructure maintenance of power companies the geographic information systems are increasingly used to support the management of theirs resources. Their functionalities in terms creating comprehensive databases for electrical infrastructure of power sector are described. The important information technology tools regarding spatial systems for supporting maintenance and operation management electrical grids and the conditions of their implementation are presented. This paper also attempts to innovative multidimensional evaluate the technical and economic benefits resulting from the use of modern information technology tools for the management of energy infrastructure.
Selected manufacturing difficulties encountered during setup of machining on cnc multi-axis linear automatic lathe and on cnc multi-spindle turning centers
- Piotr Sender
2021 Pełny tekst
The article presents the observed manufacturing technology implementation difficulties in workshop practice, resulting from the construction and principles of operation on the DMG’s SPRINT 32/5 CNC linear automatic lathe and on the Mazak’s HQR 150 MSY and QTN 200 MS CNC turn - mill centers, and discusses possible rules for solving the production problems encountered. The article also discusses the principles of dividing the machining process and working steps on multi-spindle CNC turn - mill centers. It is worth to build a system supporting the selection of the sequence of treatments [1], taking into account the frequency of natural vibrations and stiffness obtained after each single machining operations. The article shows the method of verification of the selection of the machining planning method on CNC multi-spindle lathes.
Selected problems of decision making modelling in power engineering
- Waldemar Kamrat
2021 Pełny tekst Sustainable Energy Technologies and Assessments
The paper presents the selected problems of decision making modelling in power engineering specially investment risk evaluation methods. The proposed model can be used in the range programming the development and investing process in power engineering. Decision making problems in power engineering and the evaluation of investment effectiveness in particular are closely related to modelling which relatively accurately reflects the complexity of market economy mechanisms. In order to analyze the phenomena mentioned above, models of existing processes, which are later used to achieve a set goal during decision making in a real situation, are applied. Its mathematical representation is a formalization of a model of a decision making task. A significant task in the whole process is to design a mathematical model, optimized by means of a goal function, whose arguments are decision variables meeting defined boundary conditions. Descriptions of decision making processes show that variables usually have non-negative values. Also the economic environment influences the quality of modelling. The dynamics of events causes that models of decision making processes can be analyzed. An attempt to take into account the influence of the factors mentioned above on the modelling of decision making in power engineering is presented in this paper.
Selection of an artificial pre-training neural network for the classification of inland vessels based on their images
- Katarzyna Bobkowska
- Izabela Bodus-olkowska Izabela
2021 Pełny tekst Zeszyty Naukowe Akademii Morskiej w Szczecinie
Artificial neural networks (ANN) are the most commonly used algorithms for image classification problems. An image classifier takes an image or video as input and classifies it into one of the possible categories that it was trained to identify. They are applied in various areas such as security, defense, healthcare, biology, forensics, communication, etc. There is no need to create one’s own ANN because there are several pre-trained networks already available. The aim of the SHREC projects (automatic ship recognition and identification) is to classify and identify the vessels based on images obtained from closed-circuit television (CCTV) cameras. For this purpose, a dataset of vessel images was collected during 2018, 2019, and 2020 video measurement campaigns. The authors of this article used three pre-trained neural networks, GoogLeNet, AlexNet, and SqeezeNet, to examine the classification possibility and assess its quality. About 8000 vessel images were used, which were categorized into seven categories: barge, special-purpose service ships, motor yachts with a motorboat, passenger ships, sailing yachts, kayaks, and others. A comparison of the results using neural networks to classify floating inland units is presented.
Selective monitoring of noise emitted by vehicles involved in road traffic
- Andrzej Czyżewski
- Tomasz Śmiałkowski
2021 Pełny tekst Journal of the Acoustical Society of America
An acoustic intensity probe was developed measures the sound intensity in three orthogonal directions, making possible to calculate the azimuth and elevation angles, describing the sound source position. The acoustic sensor is made in the form of a cube with a side of 10 mm, on the inner surfaces of which the digital MEMS microphones are mounted. The algorithm works in two stages. The first stage is based on the analysis of sound intensity signals, and it detects acoustic events. The second stage analyses a detection function based on the normalized source position; its task is to determine whether the acoustic event represents a vehicle passing the sensor and detecting its movement direction. The acoustic probes were mounted inside intelligent lamps that illuminate the roadways depending on the volume of traffic. The paper explains how accurately traffic can be monitored through directional noise analysis and shows the resulting application to smart cities.
Selenium enrichment in broccoli sprouts as an initial step in the preparation of Certified Reference Material
- Chintankumar Padariya
- Małgorzata Rutkowska
- Piotr Konieczka
2021 Pełny tekst
Selenium is considered one of the essential elements in animals and humans. The main source of selenium intake for humans is the diet. Selenium deficiency has one of the most concerning issues worldwide. Broccoli sprouts are five-to-six-day old broccoli plants, and they may exhibit stronger chemoprotective effects. Thus, the enrichment of selenium in broccoli sprouts can enhance anticancer properties. As a result of conducted study, four batches of selenium enriched sprouts have been produced in order to verify the efficiency of selenium uptake by broccoli sprouts under commercial conditions. –1 Sodium selenite solution (10 mg L ) was used to prepare seleniumenriched broccoli sprouts. Sodium selenite is available for biological uptake by plants. The results might be different while the addition of sodium selenite in each step of the germination process could enhance the concentration of selenium in broccoli sprouts. Therefore, it could be potentially selected as a candidate for certified reference materials
Self Portrait with a Mask
- Paweł Sasin
2021 Pełny tekst Sztuka i Dokumentacja
Paweł SASIN - Self Portrait with a Mask “Every work of art is the child of its time, and, in many cases, the mother of our emotions. “ Wassily Kandynsky, Concerning the Spiritual in Art The two years 2020 and 2021 were marked by the COVID-19 pandemic – a lengthy period of time in which everyone felt in danger of losing one’s health or life. As a result, many people were experiencing negative emotion, becoming subject to psychological stress: feeling anxious, fearful, frustrated, upset, depressed. In such situations, finding motivations to overcome these feelings is crucial and positive, as it helps people to overcome inactivity and achieve goals. During the phase of stress mobilization, one often experiences elevated efficiency of intellectual and cognitive processes: the ability to make associations and conceive unique ideas is enhanced, as well as one’s sensitivity to stimuli; which results in people accessing a greater range of their potential abilities (Frączek, Kofta, „Frustracja i stres psychologiczny”/ “Frustration and Psychological Stress”). What I am about to present is an attempt to address the question of the influence which the COVID-19 pandemic, as a socially challenging experience, may have had on the spontaneity and authenticity of creative imagination possessed by people studying architecture. Obligatory isolation, social distancing and other restraining regulations, dangers stemming from the infectious qualities of the disease, finally the huge number of gravely ill and deceased victims – those circumstance served as a trigger to ask architecture students at the Gdańsk University of Technology to create a piece on the topic Self Portrait with a Mask as part of their sculpture course.
Self-assembly of vertically oriented graphene nanostructures: multivariate characterisation by Minkowski functionals and fractal geometry
- Mattia Pierpaoli
- Mateusz Ficek
- Paweł Jakóbczyk
- Jakub Karczewski
- Robert Bogdanowicz
2021 Pełny tekst ACTA MATERIALIA
The enormous self-assembly potential that graphene and its derived layered materials offer for responding to the contemporary environmental challenges has made it one of the most investigated materials. Hence, tuning its extraordinary properties and understanding the effect at all scales is crucial to tailoring highly customised electrodes. Vertically oriented graphene nanostructures, also known as carbon nanowalls (CNWs), due to the large surface area and unique maze-like morphology, have attracted attention as a platform for advanced sensing applications. In this work, a holistic investigation approach has been developed to disrupt the synthesis-composition-structure-property paradigm and to dig out the hidden materials relationships. To achieve that, autonomous advanced image-analysis methods (Minkowski Functionals, Fractal Analysis) have been applied to SEM micrographs and successfully classified them. Morphological, electrical, and electrochemical characterisation has been performed for all of the samples. Multivariate data analysis has been employed to mine the relationships between the material features, specifically as it relates to the understanding of the intrinsic properties. As a result, this study is intended to both shed light on CNWs as a promising transparent hybrid electrochemical substrate for perfectly assembled electrochemical devices and to provide a new flexible method for nanomaterial design, characterisation and exploitation.
Self-assembly, stability and conductance of amphotericin B channels: bridging the gap between structure and function
- Joanna Zielińska
- Miłosz Wieczór
- Paweł Chodnicki
- Ewa Grela
- Rafał Luchowski
- Łukasz Nierzwicki
- Tomasz Bączek
- Wiesław I. Gruszecki
- Jacek Czub
2021 NANOSCALE
Amphotericin B (AmB), one of the most powerful but also toxic drugs used to treat systemic mycoses, is believed to selectively permeabilize fungal cell membranes to ions in a sterol-dependent manner. Unfortunately, the structure of the biologically active AmB channels has long eluded researchers, obstructing the design of safer alternatives. Here, we investigate the structural and thermodynamic aspects of channel formation, stability, and selective ion conduction. We combine fluorescence lifetime imaging and molecular simulations to trace the process of channel assembly until the formation of stable, roughly octameric double-length channels (DLCs). This stoichiometry is confirmed by matching the predicted channel conductances with the past results of patch-clamp measurements. We then use free energy calculations to explain the effect of sterols on DLC stability and discuss the observed cation selectivity in structural terms, addressing several long-standing controversies in the context of their physiological relevance. Simulations of ion permeation indicate that only solvated ions pass through DLCs, revealing surprising solvation patterns in the channel lumen. We conclude our investigation by inspecting the role of the tail hydroxyl in the assembly of functional channels, pointing at possible origins of the cholesterol–ergosterol selectivity.
Self-assessment of competencies of students and graduates participating in didactic projects – Case study
- Małgorzata Gawrycka
- Justyna Kujawska
- Michał Tomczak
2021 Pełny tekst International Review of Economics Education
Aim/purpose: the aim of this article is to examine the opinions of students and graduates of the faculty of economics of a technical university as regards their selfassessment of their preparation for entering the modern labour market. All the respondents participated during their studies in didactic projects aimed at improving their competencies taking into account the expectations of potential employers. Design/methodology/approach: the study was quantitative in nature and was carried out using the CAWI method. In the analysis of the study results, elements of descriptive statistics were used, such as: mean measures, structure indicators, structure similarity indicators and tests for the significance of mean values. A comparative analysis was conducted between two groups of respondents – students and graduates. Findings: the conducted study shows that by organising additional training for students, the university contributes to supplementing their theoretical and practical knowledge in the area of competencies required by the labour market today, in particular within the scope of specialist and technical competencies which are becoming indispensable in the Economy 4.0. Research implications/limitations: due to the small size of the test sample, the results should be treated with caution, are not representative and constitute only a case study. Originality/value/contribution: the results of the research confirm the importance of lifelong learning as regards reducing the competence gap among university graduates. The tools used in the above-mentioned process include additional training activities, such as the presented didactic projects addressed to students, complementary to the curriculum of studies. They enabled the students to extend their competencies even before they left the walls of the university and, as a result, facilitated their entry into the labour market.
Self-employment of women: an opportunity or the last resort?
- Dagmara Nikulin
2021
It is believed that automatization and technological changes will be the main drivers of work in the future. At the same time, there is a growing discussion about new forms of employment, such as self-employment. It may be either perceived as a chance for empowerment, through creating new job opportunities, that were not reachable previously, or as precarious work, with less stability, higher risk, and uncertain income. The main goal of this work is to analyze what makes women choose self-employment. Our cross-country study, conducted for 31 European countries based on 2014 European Labour Force Survey (LFS), brings a new perspective on the phenomenon. Our results suggest that self-employment may constitute an opportunity for women as higher level of skills and older age increase the probability of becoming self-employed. Moreover, as skilled people predominantly show greater skills related to the use of technology, one may conclude that the use of ICT may reinforce this form of work. On the other hand, self-employed women’s work is to a greater extent based on part-time arrangements and is frequently performed in the evenings. For this reason, it may be concluded that self-employment is an option for women who have to combine family life with work and have no chance to find typical paid employment.
Self-Organising map neural network in the analysis of electromyography data of muscles acting at temporomandibular joint.
- Mateusz Troka
- Wiktoria Wojnicz
- Katarzyna Szepietowska
- Izabela Lubowiecka
2021
The temporomandibular joint (TMJ) is the joint that via muscle action and jaw motion allows for necessary physiological performances such as mastication. Whereas mandible translates and rotates [1]. Estimation of activity of muscles acting at the TMJ provides a knowledge of activation pattern solely of a specific patient that an electromyography (EMG) examination was carried out [2]. In this work, a Self-Organising Maps (SOMs) based method was used to identify a hidden similarities in EMG data between different patients. Artificial Neural Network algorithm used for this work – Supervised Kohonen Network (SKN) was proposed and described in [3] and extended into a MATLAB toolbox by [4]. SKN algorithm was used to simulate the model, resulting in a chart called class profiles describing the calculated averages of the Kohonen weights of each variable. It shows how data similarity coming from different subjects is distributed. The obtained results let one to draw a conclusion about muscle significance during specific motion. This SOM based modelling method was intended to estimate TMJ instability and its muscle performance during jaw motions. The study was an attempt to identify and categorise patients with similarly possible disorders in TMJ area which can be evaluated from their muscles activation data.
Semantic segmentation training using imperfect annotations and loss masking
- Adam Brzeski
- Jan Cychnerski
- Tomasz Dziubich
- Tomasz Gilewicz
- Jan Woś
2021
One of the most significant factors affecting supervised neural network training is the precision of the annotations. Also, in a case of expert group, the problem of inconsistent data annotations is an integral part of real-world supervised learning processes, well-known to researchers. One practical example is a weak ground truth delineation for medical image segmentation. In this paper, we have developed a new method of accurate segmentation of blood vessels based on a convolutional neural network. We focused on imperfect annotations for the semantic segmentation of blood vessels and introduced a concept of uncertainty masks and loss masking. These uncertainty masks can be created roughly by non-experts, which makes annotation process cheaper and faster. Quantitative results of our method on a real-world problem with missing annotations and on a perfectly labeled data set with artificially introduced noise are presented. Models trained with loss masking seem to be more robust regardless of the number of removed vessels. Noise robustness of four different model architectures has been tested and compared to the loss masking method, which turned out to have better performance during training on noisy data
SENSITIVITY ANALYSIS IN THE REHABILITATION OF HISTORIC TIMBER STRUCTURES ON THE EXAMPLES OF GREEK CATHOLIC CHURCHES IN POLISH SUBCARPATHIA
- Katarzyna Szepietowska
- Izabela Lubowiecka
2021
This work concerns structural and sensitivity analysis of carpentry joints used in historic wooden buildings in south-eastern Poland and western Ukraine. These are primarily sacred buildings and the types of joints characteristic for this region are saddle notch and dovetail joints. Thus, in the study the authors focus on these types of corner log joints. Numerical models of the joints are defined and finite element simulations of their statics are carried out. Moreover, a sensitivity analysis is performed in order to describe how the uncertainty of material properties including humidity of some structural members, caused during potential repairs, affect the structural behaviour of the whole connection. This represents the situation when some degraded logs are exchanged into new wood combining old, and often damp, wood with new and dry logs. A non-intrusive probabilistic approach to the sensitivity analysis is applied and regression-based Polynomial Chaos (PC) expansion method is used to propagate uncertainties.
Sensors and Sensor’s Fusion in Autonomous Vehicles
- Andrzej Stateczny
- Marta Wlodarczyk-Sielicka
- Paweł Burdziakowski
2021 Pełny tekst SENSORS
Autonomous vehicle navigation has been at the center of several major developments, both in civilian and defense applications. New technologies such as multisensory data fusion, big data processing, and deep learning are changing the quality of areas of applications, improving the sensors and systems used. New ideas such as 3D radar, 3D sonar, LiDAR, and others are based on autonomous vehicle revolutionary development. The Special Issue entitled “Sensors and Sensor’s Fusion in Autonomous Vehicles” was focused on many aspects of autonomous vehicle sensors and their fusion, such as autonomous navigation, multi-sensor fusion, big data processing for autonomous vehicle navigation, sensors related to science/research, algorithms/technical development, analysis tools, synergy with sensors in navigation, and artificial intelligence methods for autonomous vehicle navigation.
Sequence-dependent structural properties of B-DNA: what have we learned in 40 years?
- Gabriela da Rosa
- Leandro Grille
- Victoria Calzada
- Katya Ahmad
- Juan Pablo Arcon
- Federica Battistini
- Genís Bayarri
- Thomas Bishop
- Paolo Carloni
- Thomas Cheatham III
- Rosana Collepardo-Guevara
- Jacek Czub
- Jorge R. Espinosa
- Rodrigo Galindo-Murillo
- Sarah A. Harris
- Adam Hospital
- Charles Laughton
- John H. Maddocks
- Agnes Noy
- Modesto Orozco
- Marco Pasi
- Alberto Pérez
- Daiva Petkevičiūtė-Gerlach
- Rahul Sharma
- Ran Sun
- Pablo D. Dans
2021 Pełny tekst Biophysical Reviews
The structure of B-DNA, the physiological form of the DNA molecule, has been a central topic in biology, chemistry and physics. Far from uniform and rigid, the double helix was revealed as a flexible and structurally polymorphic molecule. Conformational changes that lead to local and global changes in the helix geometry are mediated by a complex choreography of base and backbone rearrangements affecting the ability of the B-DNA to recognize ligands and consequently on its functionality. In this sense, the knowledge obtained from the sequence-dependent structural properties of B-DNA has always been thought crucial to rationalize how ligands and, most notably, proteins recognize B-DNA and modulate its activity, i.e. the structural basis of gene regulation. Honouring the anniversary of the first high-resolution X-ray structure of a B-DNA molecule, in this contribution, we present the most important discoveries of the last 40 years on the sequence-dependent structural and dynamical properties of B-DNA, from the early beginnings to the current frontiers in the field.
Series-Slot-Fed Circularly Polarized Multiple-Input-Multiple-Output Antenna Array Enabling Circular Polarization Diversity for 5G 28-GHz Indoor Applications
- Ubaid Ullah
- Muath Al-hasan
- Ismail Mabrouk
- Sławomir Kozieł
2021 Pełny tekst IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
In this paper, a four-element circularly polarized series-slot-fed multiple-input-multiple-output (MIMO) antenna array with circular polarization diversity is presented. The proposed design utilizes a combination of 45-degree inclined slots and a straight microstrip line feeding technique. The two antennas are designed to operate with the opposite sense of circular polarization (CP). CP is achieved by placing a patch of just about square dimensions on the top of the V-slot with orthogonal but unequal arms. The unequal arm of the slot degenerates the fundamental mode at a slightly different frequency with 90-degree phase difference occurring at the center frequency of each arm. Proper positioning of the patch on the top of the slot ensures excitation of CP. For realizing a MIMO antenna with different sense of polarization, both the slots and the patches are flipped with respect to the feedline. Following optimization at the full-wave level of description, the antenna is prototyped and validated experimentally. The realizable antenna footprint is 20 mm × 27.7 mm. The simulated and measured results indicate that the proposed antenna features a wide impedance bandwidth (|S11|<-10 dB) from 26.9 GHz to 30.7 GHz, 3 dB axial ratio bandwidth from 27.31 GHz to 29.65 GHz and the peak realized gain of 11.86 dBic. Moreover, it exhibits a low level of in-band isolation |S21|>-37 dB and almost negligible envelope correlation coefficient (ECC), less than 0.00025. The highly directional beams, high gain and compact size of the proposed antenna permit implementation of multiple antennas for indoor applications in the 28-GHz band.
Serotonergic–Muscarinic Interaction within the Prefrontal Cortex as a Novel Target to Reverse Schizophrenia-Related Cognitive Symptoms
- Paulina Cieślik
- Adrianna Radulska
- Grzegorz Burnat
- Leszek Kalinowski
- Joanna M. Wierońska
2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Recent studies revealed that the activation of serotonergic 5-HT1A and muscarinic M1, M4, or M5 receptors prevent MK-801-induced cognitive impairments in animal models. In the present study, the effectiveness of the simultaneous activation of 5-HT1A and muscarinic receptors at preventing MK-801-induced cognitive deficits in novel object recognition (NOR) or Y-maze tests was investigated. Activators of 5-HT1A (F15599), M1 (VU0357017), M4 (VU0152100), or M5 (VU0238429) receptors administered at top doses for seven days reversed MK-801-induced deficits in the NOR test, similar to the simultaneous administration of subeffective doses of F15599 (0.05 mg/kg) with VU0357017 (0.15 mg/kg), VU0152100 (0.05 mg/kg), or VU0238429 (1 mg/kg). The compounds did not prevent the MK-801-induced impairment when administered acutely. Their activity was less evident in the Y-maze. Pharmacokinetic studies revealed high brain penetration of F15599 (brain/plasma ratio 620%), which was detected in the frontal cortex (FC) up to 2 h after administration. Decreases in the brain penetration properties of the compounds were observed after acute administration of the combinations, which might have influenced behavioral responses. This negative effect on brain penetration was not observed when the compounds were administered repeatedly. Based on our results, prolonged administration of a 5-HT1A activator with muscarinic receptor ligands may be effective at reversing cognitive decline related to schizophrenia, and the FC may play a critical role in this interaction.
Service-based Resilience via Shared Protection in Mission-critical Embedded Networks
- Doganalp Ergenc
- Jacek Rak
- Mathias Fischer
2021 Pełny tekst IEEE Transactions on Network and Service Management
Mission-critical networks, which for example can be found in autonomous cars and avionics, are complex systems with a multitude of interconnected embedded nodes and various service demands. Their resilience against failures and attacks is a crucial property and has to be already considered in their design phase. In this paper, we introduce a novel approach for optimal joint service allocation and routing, leveraging virtualized embedded devices and shared backup capacity for the fault-tolerant design of mission-critical networks. This approach operates in phases utilizing multiple optimization models. Furthermore, we propose a new heuristic that ensures resource efficiency and fault-tolerance against single node and link failures as pre-requisite for resilience. Our experiments for different application scenarios indicate that our heuristic achieves results close to the optimum and provides 50% of capacity gain compared to a dedicated capacity protection scheme. Moreover, our heuristic ensures fault-tolerance against at least 90% of all potential single node failures.
Seven Different Lighting Conditions in Photogrammetric Studies of a 3D Urban Mock-Up
- Katarzyna Bobkowska
- Paweł Burdziakowski
- Jakub Szulwic
- Karolina Zielińska-Dąbkowska
2021 Pełny tekst ENERGIES
One of the most important elements during photogrammetric studies is the appropriate lighting of the object or area under investigation. Nevertheless, the concept of “adequate lighting” is relative. Therefore, we have attempted, based on experimental proof of concept (technology readiness level—TRL3), to verify the impact of various types of lighting emitted by LED light sources for scene illumination and their direct influence on the quality of the photogrammetric study of a 3D urban mock-up. An important issue in this study was the measurement and evaluation of the artificial light sources used, based on illuminance (E), correlated colour temperature (CCT), colour rendering index (CRI) and Spectral power distribution (SPD) and the evaluation of the obtained point clouds (seven photogrammetric products of the same object, developed for seven different lighting conditions). The general values of the quality of the photogrammetric studies were compared. Additionally, we determined seventeen features concerning the group of tie-points in the vicinity of each F-point and the type of study. The acquired traits were related to the number of tie-points in the vicinity, their luminosities and spectral characteristics for each of the colours (red, green, blue). The dependencies between the identified features and the obtained XYZ total error were verified, and the possibility of detecting F-points depending on their luminosity was also analysed. The obtained results can be important in the process of developing a photogrammetric method of urban lighting monitoring or in selecting additional lighting for objects that are the subject of a short-range photogrammetric study.