Publications Repository - Gdańsk University of Technology

Page settings

polski
Publications Repository
Gdańsk University of Technology

Show publications from the year

Publications from the year 2022

Show all
  • Przęsło łukowe kolejowego obiektu mostowego. Wpływ schematu statycznego i rozwiązań konstrukcyjnych na właściwości dynamiczne
    • Przemysław Kalitowski
    2022 Full text

    W pracy przedstawiono kompleksową analizę optymalizacyjną kolejowego wiaduktu łukowego. Szczególną uwagę zwrócono na zachowanie dynamiczne konstrukcji. Odpowiedź dynamiczna przęsła pod obciążeniem taboru Kolei Dużych Prędkości (KDP) jest jednym z kluczowych elementów podlegających ocenie przy projektowaniu obiektów wzdłuż KDP. Drgania przęsła ograniczane są ze względu na trwałość i bezpieczeństwo konstrukcji oraz komfort pasażerów. Sformułowano procedurę, w której połączono analizę numeryczną Metodą Elementów Skończonych oraz wielokryterialną optymalizację rojem cząstek (PSO) do poszukiwania zestawu najlepszych rozwiązań ze względu na ilość zużytego materiału i odpowiedź dynamiczną konstrukcji. Procedurę zaprezentowano na przykładzie istniejącego łukowego wiaduktu kolejowego WK-2 o rozpiętości 70 m w ciągu Pomorskiej Kolei Metropolitalnej. Parametry dynamiczne obiektu zidentyfikowano za pomocą procedury NExT-ERA Operacyjnej Analizy Modalnej. Zbudowany model MES skalibrowano wykorzystując wyniki badań i metodę optymalizacji PSO. Przeanalizowano dziewięć wariantów optymalizacji różniących się układem wieszaków oraz maksymalną prędkością przejazdu. Uwzględniono wieszaki pionowe, ukośne i Network oraz prędkości 160, 200 i 300 km/h. Zestawione wyniki pozwoliły na ocenę przydatności i opłacalności poszczególnych wariantów konstrukcji w zastosowaniach w ciągu KDP. Podjęto również próbę określenia zależności pomiędzy wielkością głównych elementów konstrukcyjnych, a odpowiedzią dynamiczną wiaduktu.

  • Przyczyna uszkodzeń uzwojeń silników 6 kV 500 kW, zainstalowanych w pompowni ujęcia wody
    • Dariusz Karkosiński
    • Dawid Łuszcz
    • Marek Olesz
    2022 Automatyka Elektryka Zakłócenia

    W artykule przedstawiono analizę przyczyn uszkodzeń silników średniej mocy i SN, służących do napędu pomp ujęcia wody dla miasta. Użytkownik pompowni w celu regulacji wydatku pomp zastosował przemiennik częstotliwości niskiego napięcia, których został zasilony przez transformator 6/0,4 kV. Napięcie za przemiennikiem było podnoszone poprzez transformator 0,4/6 kV i zasilało poprzez linie kablowe silniki pomp. W ciągu 2. lat od wdrożenia regulacji częstotliwościowej, w 3. silnikach wystąpiły uszkodzenie izolacji. Powodem tego zjawiska były chwilowe napięcie aż 2. krotnie większe od wartości dopuszczalnej.

  • Przyszłość fotowoltaiki – czy zaleje nas fala odpadów?
    • Ewa Klugmann-Radziemska
    2022 Full text Pismo PG

    Rozwój fotowoltaiki na świecie utrzymuje się przez ostatnie 40 lat na bardzo wysokim, 40-procentowym wzroście rok-do-roku. Również w Polsce obserwujemy od kilku lat rosnące zainteresowanie, zwłaszcza instalacjami prosumenckimi, głównie dzięki licznym programom wspierającym inwestycje. Znaczny udział systemów fotowoltaicznych w generowaniu energii elektrycznej na całym świecie przynosi niewątpliwe korzyści dla środowiska naturalnego, ponieważ systemy te nie są źródłem hałasu ani emisji szkodliwych substancji czy gazów cieplarnianych. Energia elektryczna wytwarzana z paliw kopalnych odpowiada za emisję gazów cieplarnianych na poziomie od 400 g do 1000 g CO2eq./kWh, podczas gdy ich emisja z krzemowych modułów fotowoltaicznych jest znikoma. Zakłada się, że moduły fotowoltaiczne powinny pełnić swoją funkcję 25 lat. Jednak, aby pozostały one bez negatywnego wpływu na środowisko, konieczne jest wprowadzenie długofalowej strategii obejmującej kompletny cykl życia wszystkich elementów systemu: od fazy produkcji, poprzez montaż i eksploatację aż do zagospodarowania odpadów. Recykling zużytych lub uszkodzonych modułów jest istotnym elementem tej strategii.

  • Psychological capital and happiness at work: The mediating role of employee thriving in multinational corporations
    • Beata Basińska
    • Małgorzata Rozkwitalska
    2022 Full text CURRENT PSYCHOLOGY

    Working in multicultural work environments of multinational corporations (MNCs) creates challenges whose expected impact on happiness is equivocal. In the following paper, we examine the relationship between psychological capital and happiness at work in the specific MNCs’ context. We assume that thriving (eudemonic well-being) at work fosters individuals’ development and enhances their happiness composed of both the affective (positivity) and cognitive (satisfaction with intercultural interactions) components. A sample of 137 individuals from subsidiaries of various MNCs and involved in intercultural interactions was included in the cross-sectional study. In order to test the mediating effect of vitality and learning, i.e., both components of thriving, on the psychological capital and happiness at work, as well as a moderating effect of psychological capital between thriving and happiness in a multicultural work setting, a bootstrapping analysis was conducted. Prior international experience and job tenure were control variables. The results show that psychological capital as resource caravans is positively associated with learning and further is related to more satisfaction with intercultural interactions. Moreover, psychological capital is associated with more vitality at work and further favourably relates to positivity. We also demonstrate that psychological capital does not moderate the relationship between thriving and happiness at work. The research broadens the understanding of positive aspects of well-being in the unique environment of MNCs. Our study suggests that managers should stimulate learning and vitality by managerial practices concerning improvement of employee psychological capital since then they may strengthen happiness at work.

  • pt. „PRZYSTANEK OD ZGIEŁKU MIASTA # Gdańsk-Letnica”
    • Agnieszka Kurkowska
    2022

    plakat promujący wystawę pt. „PRZYSTANEK OD ZGIEŁKU MIASTA # Gdańsk-Letnica” w mediach społecznościowych oraz fizycznie w siedzibie GAK Gama w Gdańsku-Letnicy

  • Public Finance in Poland in a COVID Fog: A Look Through the Lens of Fiscal Transparency and Accountability
    • Maria Jastrzębska
    2022 Full text Studies in Logic, Grammar and Rhetoric

    Abstract. Goal– The aim of the article is to identify dysfunctional phenomena (implementation of specific mechanisms/solutions and actions taken), generating increased opacity and limit the responsibility/accountability of public f inance in Poland, exacerbated by the COVID-19 crisis. Methods– descriptive analysis, comparative analysis and financial analysis methods were used. Results– fiscal transparency and accountability in Poland is limited by: the marginalisation of the role of the state budget, the loosening of the stabilising expenditure rule, the creation of financial mechanisms based on special funds fed by repayable financing sources for the implementation of state tasks, inter alia, in the fight against the effects of the COVID-19 crisis, the use of national and EU methodologies for calculating the deficit and debt of the public sector in order to conceal part of them, the lack of a consolidated financial statement of the public finance sector.

  • Pure cross-anisotropy for geotechnical elastic potentials
    • Andrzej Niemunis
    • Katarzyna Staszewska
    2022 Full text Acta Geotechnica

    The pure cross-anisotropy is understood as a special scaling of strain (or stress). The scaled tensor is used as an argument in the elastic stiffness (or compliance). Such anisotropy can be overlaid on the top of any elastic stiffness, in particular on one obtained from an elastic potential with its own stress-induced anisotropy. This superposition does not violate the Second Law. The method can be also applied to other functions like plastic potentials or yield surfaces, wherever some cross-anisotropy is desired. The pure cross-anisotropy is described by the sedimentation vector and at most two constants. Scaling with more than two purely anisotropic constants is shown impossible. The formulation was compared with experiments and alternative approaches. Static and dynamic calibration of the pure anisotropy is also discussed. Graphic representation of stiffness with the popular response envelopes requires some enhancement for anisotropy. Several examples are presented. All derivations and examples were accomplished using the algebra program Mathematica.

  • Pursuing Analytically the Influence of Hearing Aid Use on Auditory Perception in Various Acoustic Situations
    • Piotr Szymański
    • Tomasz Poremski
    • Bożena Kostek
    2022 Full text Vibrations in Physical Systems

    The paper presents the development of a method for assessing auditory perception and the effectiveness of applying hearing aids for hard-of-hearing people during short-term (up to 7 days) and longer-term (up to 3 months) use. The method consists of a survey based on the APHAB questionnaire. Additional criteria such as the degree of hearing loss, technological level of hearing aids used, as well as the user experience are taken into consideration. A web-based application is developed, allowing answering the survey questions from any computer with Internet access. The results of the benefit obtained from the use of hearing aids in various acoustic environments, taking into account the time of their use, are presented and compared to the earlier outcomes. The research results show that in the first period of use of hearing aids, speech perception improves, especially in noisy environments. The perception of unpleasant sounds also increases, which may lead to deterioration of hearing aid acceptance by their users.

  • Pursuing Listeners’ Perceptual Response in Audio-Visual Interactions - Headphones vs Loudspeakers: A Case Study
    • Bartłomiej Mróz
    • Bożena Kostek
    2022 Full text Archives of Acoustics

    This study investigates listeners’ perceptual responses in audio-visual interactions concerning binaural spatial audio. Audio stimuli are coupled with or without visual cues to the listeners. The subjective test participants are tasked to indicate the direction of the incoming sound while listening to the audio stimulus via loudspeakers or headphones with the head-related transfer function (HRTF) plugin. First, the methodology assumptions and the experimental setup are described to the participants. Then, the results are presented and analysed using statistical methods. The results indicate that the headphone trials showed much higher perceptual ambiguity for the listeners than when the sound is delivered via loudspeakers. The influence of the visual modality dominates the audio-visual evaluation when loudspeaker playback is employed. Moreover, when the visual stimulus is present, the headphone playback pattern of behavior is not always in response to the loudspeaker playback.

  • Pursuing the Deep-Learning-Based Classification of Exposed and Imagined Colors from EEG
    • Alejandro A. Torres-García
    • Jesus Garcia Salinas
    • Luis Villaseñor-Pineda
    2022 LECTURE NOTES IN COMPUTER SCIENCE

    EEG-based brain-computer interfaces are systems aiming to integrate disabled people into their environments. Nevertheless, their control could not be intuitive or depend on an active external stimulator to generate the responses for interacting with it. Targeting the second issue, a novel paradigm is explored in this paper, which depends on a passive stimulus by measuring the EEG responses of a subject to the primary colors (red, green, and blue). Particularly, we assess if a compact and feature-extraction-independent deep learning method (EEGNet) can effectively learn from these EEG responses. Our outcomes outperformed previous works focused on a dataset composed of EEG signals belonging to 7 subjects while seeing and imagining three primary colors. The method reaches an accuracy of 45% for exposed colors, 43% for imagined colors, and 35% for the six classes. Last, the experiments suggest that EEGNet learned to discover patterns in the EEG signals recorded for imagined and exposed colors, and for the six classes, too.

  • Pyrolysis Combined with the Dry Reforming of Waste Plastics as a Potential Method for Resource Recovery—A Review of Process Parameters and Catalysts
    • Ewelina Pawelczyk
    • Izabela Wysocka
    • Jacek Gębicki
    2022 Full text Catalysts

    : Emissions of greenhouse gases and growing amounts of waste plastic are serious environmental threats that need urgent attention. The current methods dedicated to waste plastic recycling are still insufficient and it is necessary to search for new technologies for waste plastic management. The pyrolysis-catalytic dry reforming (PCDR) of waste plastic is a promising pro-environmental way employed for the reduction of both CO2 and waste plastic remains. PCDR allows for resource recovery, converting carbon dioxide and waste plastics into synthetic gas. The development and optimization of this technology for the high yield of high-quality synthesis gas generation requires the full understanding of the complex influence of the process parameters on efficiency and selectivity. In this regard, this review summarizes the recent findings in the field. The effect of process parameters as well as the type of catalyst and feedstock are reviewed and discussed.

  • Pyrolysis of RDF and Catalytic Decomposition of the Produced Tar in a Char Bed Secondary Reactor as an Efficient Source of Syngas
    • Bogusław Kusz
    • Dariusz Kardaś
    • Łukasz Heda
    • Bartosz Trawiński
    2022 Full text Processes

    One of the technical limitations of refuse-derived fuel (RDF) pyrolysis is the high content of tar in its gas products. In order to resolve this problem, a two-stage RDF pyrolysis with a catalyst based on char from RDF pyrolysis is proposed. This paper presents the results of municipal waste pyrolysis beginning in an oven heated to 480 °C and ending with catalytic tar cracking carried out in the temperature range from 800 to 1000 °C. Thermal and catalytic pyrolysis with a char catalyst containing a minimum of 6% Fe resulted in increases in the CO and H2 contents in gas products and decreases in CO2 and CH4. At 1000 °C, the mass ratio of gaseous products to liquids was greater than 6. The residence time of the gases in the catalytic zone was about 3–5 s. The reactor was a good source of hydrogen and carbon monoxide.

  • Pyrrole bearing diazocrowns: Selective chromoionophores for lead(II) optical sensing
    • Błażej Galiński
    • Ewa Wagner-Wysiecka
    2022 Full text SENSORS AND ACTUATORS B-CHEMICAL

    Diazocrowns of 18-, 21- and 23-membered rings with pyrrole residue as a part of macrocycle were for the first time used as chromoionophores in lead(II) selective optodes. Sensing properties of optodes depend on the type of macrocycle, namely its size and the type of linker: oligoether or hydrocarbon chain. The best results were obtained for optode bearing 18-membered crown with oligoether linker showing linear response range of 8.05 × 10−8–2.24 × 10−5 M lead(II) and detection limit of 1.15 × 10−8 M. Membrane, based on cellulose triacetate, is lead(II) selective giving color change from red to different shades of blue (pH 5.5). Results obtained for model and real samples of lead(II) showed that easily accessible and regenerable sensor material can be used for spectrophotometric and colorimetric (Digital Color Analysis) detection and determination of lead(II).

  • QoS Extensions for Flow-Awareness Networks
    • Sylwester Kaczmarek
    • Maciej Wolff
    2022 Full text International Journal of Electronics and Telecommunications

    The paper contains a description and research results of the proposal for distributed QoS extensions for Flow-Based Networking. These QoS extensions let the network accept or reject flows based on current network load and QoS promises for each of the flows. Proposed solution consists of two distributed components, each of them performing in every node, measurement system and access control. The solution could be applied in any network architecture that is able to distinguish flows and routers in this architecture contains flow state table. Proposed approach was verified by simulation, in FSA architecture. Verification was done for six different network structures servicing two traffic classes (MRS, ARS). The results of the simulation tests have confirmed that the average time delay and packet loss ratio in the network with proposed extensions are below thresholds and meet the requirements recommended by ITU-T.

  • QoS Resource Reservation Mechanisms for Switched Optical Networks
    • Sylwester Kaczmarek
    • Magdalena Młynarczuk
    • Arkadiusz Dumin
    2022

    The paper regards the problem of resource reservation mechanisms for Quality of Service support in switched optical networks. The authors propose modifications and extensions for resources reservation strategy algorithms with resources pools, link capacity threshold and adaptive advance reservation approach. They examine proposed solutions in Automatically Switched Optical Network with Generalized Multi-Protocol Label Switching named as ASON/GMPLS network. The analysis is performed by simulation the Polish network structure with the use of OMNeT++ discrete-event simulator.

  • QRS Morphology-Based EDR Signal—Factors Determining its Properties
    • Piotr Przystup
    • Artur Poliński
    • Jerzy Wtorek
    2022 Full text IEEE Access

    Respiration-induced signals contain a clinically significant information. It could be obtained utilizing both direct and indirect methods. ECG-Derived Respiration (EDR) method is the latter one. However, in this case, two approaches could be distinguished. First one is based on determining changes in the morphology of QRS complexes while the second one is based on the Respiratory Sinus Arrhythmia (RSA) mechanism. The former approach is discussed in the paper. The basic properties of QRS morphology-based EDR signal were evaluated by means of simulations performed using a developed FEM model and appropriate experiments. In effect, basing on changes of the leads’ voltages induced by a heart translation or rotation, or by both mechanisms undergoing simultaneously, the sensitivity-like surfaces and the synthetic EDR signals were obtained. A very good agreement of the experimental and simulation results was achieved. The QRS morphology-based signal’s properties strongly depend on geometrical relation of the used lead to dominating direction of the heart translation, its rotation, and on personal relation between these two mechanisms. The conclusions presented should be taken into account especially when developing or using QRS morphology-based approach in respiratory monitoring systems.

  • Qualia: About Personal Emotions Representing Temporal Form of Impressions - Implementation Hypothesis and Application Example
    • Zdzisław Kowalczuk
    • Michał Czubenko
    • Marlena Gruba
    2022

    The aim of this article is to present the new extension of the xEmotion system as a computerized emotional system, part of an Intelligent System of Decision making (ISD) that combines the theories of affective psychology and philosophy of mind. At the same time, the authors try to find a practical impulse or evidence for a general reflection on the treatment of emotions as transitional states, which at some point may lead to the emergence of new emotional qualities ascribed to phenomena (objects or events) perceived by the agent. Since there is a dispute in the literature about the meaning and usefulness of `private' emotions, the article attempts to present in a transparent and technical manner the problem of hypothetical qualia against the background of selected theories of emotions, taking into account the cultural aspect or division. By treating qualia as an expression of individual emotional diversity and learning capacity, qualia can be assigned a quite technical role in modeling the human mind and in implementing autonomous robots and agents.

  • Quality Analysis of Audio-Video Transmission in an OFDM-Based Communication System
    • Monika Zamłyńska
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    2022

    Application of a reliable audio-video communication system, brings many advantages. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. With the availability of visual information one can monitor the surrounding, working environment, etc. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Currently, orthogonal frequency division multiplexing (OFDM) is widely utilized both in wired and wireless transmission. In this paper we investigate the quality of service (QoS) parameters of a simulated data transmission system, dedicated particularly to audio and video content distribution with orthogonal frequency division multiplexing. The audio research part involves a group of four language sets, namely: American English, British English, German, and Polish, processed using the Ogg Vorbis format. Whereas, in the video part we investigate a set of MPEG-4 video sequences coded at standard resolution of 480 × 270 pixels. Tests were performed under varying network and bandwidth conditions, including signal-to-noise ratio (SNR) and bit error rate (BER). Results of this study may aid parties interested in designing additional backup or supplementary services for portable devices and user terminals, including reliable means of contact, surveillance and monitoring for the Industry 4.0 and Internet of things (IoT) concept.

  • Quality assessment of low voltage surge arresters
    • Leszek Litzbarski
    • Marek Olesz
    • Stanisław Wojtas
    • Michał Winiarski
    • Tomasz Klimczuk
    • Hubert Glowinski
    • Bartłomiej Andrzejewski
    2022 Full text IEEE Access

    Users expect reliable operation of the surge arrester during overvoltages, which may originate from a switching process or a lightning discharge. The necessary conditions to guarantee these expectations are: appropriate construction of the surge arrester, its production being maintained in accordance with technical standards, and a positive results of the type test (as well routine and acceptance tests). The recipient, especially when purchasing large quantities of the product, can check the final quality of the product through selective testing of samples from the market in order to find the best supplier. This manuscript specifies the basic parameters of low-voltage (LV) surge arresters of four manufacturers. Basic electrical parameters, i.e. leakage current and varistor voltage (U1mA) before and after the nominal discharge current (In) of 8 µs/20 µs, were determined for 10 randomly selected surge arresters of each manufacturer. Moreover one sample of each varistor batches was aged by fifty 8 µs/20 µs current impulses with In. The obtained results of structural analysis indicate that the crystal structure of the varistor materials changes after ageing process, affecting its electrical properties. The proposed research methodology can be employed as a basis for forecasting the stability of the arrester parameters under operating conditions.

  • Quality Control of Bacterial Extracellular Vesicles with Total Protein Content Assay, Nanoparticles Tracking Analysis, and Capillary Electrophoresis
    • Aleksandra Steć
    • Joanna Jońca
    • Krzysztof Waleron
    • Małgorzata Waleron
    • Agata Płoska
    • Leszek Kalinowski
    • Bartosz Wielgomas
    • Szymon Dziomba
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Extracellular vesicles (EVs) were isolated from Pectobacterium zantedeschiae culturing media using direct ultracentrifugation (UC), iodixanol cushion ultracentrifugation (ICUC), and iodixanol density gradient ultracentrifugation (IDGUC) techniques. The isolates were characterized with total protein content assay (bicinchoninic acid assay, BCA), nanoparticles tracking analysis (NTA), and capillary electrophoresis (CE). A satisfactory correlation (R2 > 0.94) between quantitative results obtained with BCA, NTA and CE was achieved only for isolates obtained with the IDGUC. The correlation between protein content and CE was proved to be related to the isolates’ purity. The NTA was found unable to provide reliable information on EVs quantity in samples isolated with UC and ICUC, due to the co-isolated particulate impurities. Moreover, the work reports polysaccharides, used as culturing media components, as a potential source of bias of quantitation with total protein content assay and NTA. The study demonstrates the advantageous selectivity of CE in quality control of EVs and its ability to differentiate subpopulations of EVs of Pectobacterium.