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Gdańsk University of Technology

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Publications from the year 2019

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  • Advances in Architectures, Big Data, and Machine Learning Techniques for Complex Internet of Things Systems
    • David Gil
    • Magnus Johnsson
    • Higinio Mora
    • Julian Szymański
    2019 Full text COMPLEXITY

    Te feld of Big Data is rapidly developing with a lot of ongoing research, which will likely continue to expand in the future. A crucial part of this is Knowledge Discovery from Data (KDD), also known as the Knowledge Discovery Process (KDP). Tis process is a very complex procedure, and for that reason it is essential to divide it into several steps (Figure 1). Some authors use fve steps to describe this procedure, whereas others use only four.

  • Advantages of the Application of the Temper Bead Welding Technique During Wet Welding
    • Jacek Tomków
    • Grzegorz Rogalski
    • Dariusz Fydrych
    • Jerzy Łabanowski
    2019 Full text Materials

    Thermo-mechanically rolled S460ML steel was chosen for welding in underwater wet welding conditions by covered electrodes. The main aim of this study was to check the weldability for fillet welds in a water environment by controlled thermal severity (CTS) tests and to check the influence of temper bead welding (TBW) on the weldability of the investigated steel. Non-destructive and destructive tests showed that S460ML steel has a high susceptibility to cold cracking. In all joints, hardness in the heat-affected zone (HAZ) was extended to the 400 HV10 values. Microscopic testing showed the presence of microcracks in the HAZ of all welded joints. TBW was chosen as the method to improve the weldability of the investigated steel. This technique allows for the reduction of the maximum hardness in the HAZ below the critical value of 380 HV10, as stated by the EN-ISO 15614-1:2017. It was determined that for S460ML steel, from the point of view of weldability, the pitch between two beads should be in the range 75%-100%. Also, if the pitch between two beads increases, the hardness, grain size, and number of cracks decreases. In all specimens where the hardness of the HAZ was below 380 HV10, there were no microcracks.

  • AEGIS – mobilne urządzenie do wytwarzania kurtyny elektromagnetycznej dla zastosowań specjalnych i ochrony przed RCIED
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Magiera
    • Paweł Tomasz Kosz
    • Agnieszka Czapiewska
    • Robert Burczyk
    • Jarosław Sadowski
    • Sławomir Ambroziak
    2019 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule przedstawiono założenia, projekt oraz wykonanie demonstratora technologicznego mobilnego urządzenia do wytwarzania kurtyny elektromagnetycznej. Urządzenie jest zaprojektowane do zablokowania łączności radiowej, za pomocą której możliwe byłoby zdetonowanie prowizorycznych ładunków wybuchowych. Celem jest zapewnienie bezpieczeństwa funkcjonariuszom służb państwowych takich jak Straż Graniczna, czy też Policja. W artykule zarówno przedstawiono urządzenie, jak i omówiono oprogramowanie demonstratora technologicznego, dzięki któremu możliwe jest wytworzenie szerokopasmowego sygnału zagłuszającego

  • Aeration Process in Bioreactors as the Main Energy Consumer in a Wastewater Treatment Plant. Review of Solutions and Methods of Process Optimization
    • Jakub Drewnowski
    • Anna Remiszewska-Skwarek
    • Sylwia Duda
    • Grzegorz Łagód
    2019 Full text Processes

    Due to the key role of the biological decomposition process of organic compounds in wastewater treatment, a very important thing is appropriate aeration of activated sludge, because microorganisms have to be supplied with an appropriate amount of oxygen. Aeration is one of the most energy-consuming processes in the conventional activated sludge systems of wastewater treatment technology (may consume from 50% to 90% of electricity used by a plant), which makes it the most cost-generating process incurred by treatment plants. The paper presents the construction of aeration systems, their classification as well as parameters and factors that significantly affect the aeration process e.g., oxygen transfer effciency, diffuser fouling, methods of dealing with diffuser fouling, diffuser selection. Additionally, there are briefly presented “smart control” systems in wastewater treatment and effect of application control strategy based on Supervisory Control and Data Acquisition system connected with the decrease in the energy consumption for aeration of bioreactors with activated sludge. It is noted that before the process is optimized, the system should be equipped with suitable metering devices. Only when relevant data is available, the improvements can be carried out. However, it’s important, that the operator should regularly maintain good condition and high effciency of diffusers.

  • Aerodynamics in the education of prospective architects
    • Katarzyna Zielonko-Jung
    2019 Full text World Transactions on Engineering and Technology Education

    The inclusion of issues of aerodynamics in the education of architecture students is discussed in this article. The field of aerodynamics knowledg of the nature of wind phenomena around building developments. It is especially important to know how to influence the occurrence of such phenomena by means of shaping buildings through architectural and urban design. The method applied for working with Master’s degree students in the Faculty of Architecture at Gdańsk University of Technology (FA-GUT), Gdańsk, Poland, included experimental studies in a wind tunnel. The technique allows prospective architects not only to become acquainted with a specific issue that ranges beyond their competencies, but also to attain a broader perspective on the interdisciplinary nature of building residential estates and on city design.

  • Airstrip Ground Improvement Works by Blasting Charge Technique and Dredged-Ash Material Mixture
    • Eligiusz Mieloszyk
    • Mariusz Wyroślak
    2019 Full text IOP Conference Series: Materials Science and Engineering

    Soil improvement by blasting charge technique is known in geotechnics as one of the efficient and inexpensive method. It can be used in preparing of underground to found road construction and buildings as well. The technique proves usefulness especially when dynamic load is applied. It is because of non-stiff or rather resilient type soil after improvement. In noncohesive or organic soil, blasting charge must be used with well-graded soil or similar granular material layered as working platform. Explosions cause exchange of soil. Using dredged-ash material mixture it can be benefitable in resource management and ecology. The purpose of research was finding a fast method of soil improvement to prepare special constructions like airstrips for landing and taking off light and small aircrafts. Expected results can be achieved after using blasting charge technique.

  • Aktywizacja potencjału mieszkańców miast polskich poprzez działania artystyczne w oparciu o wybrane przykłady
    • Anna Stasiak
    2019 Full text Acta Scientiarum Polonorum Administratio Locorum

    Obecnie ponad połowa mieszkańców naszego globu zamieszkuje tereny zurbanizowane. Doprowadziło to do wyraźnego zagęszczenia ludności w miastach w przeciągu kilku ostatnich dziesięcioleci, a tym samym zmienił się tryb życia ich mieszkańców. W wielotysięcznych miastach coraz trudniej jest znaleźć pretekst i możliwość do nawiązania bliższych relacji z otaczającymi nas ludźmi. Działania artystyczne związane z tworzeniem i prezentowaniem sztuki w przestrzeniach publicznych są jedną z dróg pozwalających na aktywizację potencjału mieszkańców miast. Celem artykułu jest poprzez analizę pięciu drobnoskalowych aktywności artystycznych zdefiniowanie zabiegów przestrzennych, dzięki którym można osiągnąć pozytywne efekty – uspołeczniające oraz estetyzujące przestrzeń.

  • Akustyczna analiza natężenia ruchu drogowego dla systemów zarządzania ruchem
    • Karolina Marciniuk
    2019

    W pracy przybliżono wybrane zagadnienia z dziedziny zarządzania transportem drogowym w Polsce i na świecie. W tym kontekście pzredstawiono potrzeby rynkowe, wymagania jak i możliwości w zakresie pozyskiwania informacji o aktualnym stanie sieci drogowych. Zaproponowano akustyczną metodę nadzorowania ruchu drogowego i jej możliwości w kontekście systemów zarządzania ruchem. Przedstawiono schemat akwizycji sygnału wraz z danymi odniesienia. Omówiono proces opracowywania bazy danych i metodykę procesów związanych z przetwarzaniem wstępnym sygnałów audio. Następnie przedstawiono proces selekcji parametrów użytych do detekcji obecności pojazdu. Wykryte zdarzenia poddawane były ocenie statystycznej związanej z odstępami między pojazdami (kryterium bezpiecznej odległości), a następnie przeprowadzono dokładniejszą klasyfikację. Przedstawiono metody klasyfikacji typów pojazdów na podstawie ich brzmienia, stosując podział na cztery typy pojazdów, zestawiając to z typowymi stosowanymi metodami klasyfikacji w systemach zarządzania ruchem. Dodatkowo przestawiono metodę oceny bezpieczeństwa ruchu związanej z przyczepnością pojazdu do nawierzchni drogi – poprzez akustyczne wykrywanie obecności wody i śniegu na jezdni.

  • Akustyczne zobrazowanie morskich osadów dennych
    • Wojciech Szymczak
    2019 Full text

    Przedstawiany temat rozprawy doktorskiej: „Akustyczne zobrazowanie morskich osadów dennych”, prezentuje metody zobrazowania struktury osadów dennych pozyskanych z sondowania akwenu echosondą parametryczną SES-2000 Standard oraz urządzeniami pomocniczym — echosondą wielowiązkową EM3002 i sonarem bocznym. Tezą jest wykazanie, że metody akustyczne dają możliwość bezinwazyjnej klasyfikacji osadów dennych. Hipoteza zakłada, że istnieje ścisły związek pomiędzy wynikami symulacji echogramów w oparciu o informacje geologiczną (zebrane próbki osadów dennych), wynikami pozyskanymi podczas badań laboratoryjnych oraz pomiarami w warunkach rzeczywistych. W pracy zaprezentowana została podstawowa teoria związana z nieliniowymi właściwościami ośrodka oraz modelami i parametrami geofizycznymi dna morskiego. Rozdział 5 i 6 przedstawia metodykę pomiarów oraz analizę wyników badań przeprowadzonych w warunkach laboratoryjnych i podczas pomiarów In Situ (prezentacja charakterystycznych echogramów z wybranych rejonów Zatoki Puckiej/Gdańskiej). W 7 rozdziale przedstawione zostały wyniki działania oprogramowania z zaimplementowanymi metodami wizualizacji oraz klasyfikacji osadów dennych z wybranego akwenu pomiarowego. Pracę zakończono podsumowaniem wskazującym między innymi najważniejsze samodzielne osiągnięcia naukowe autora.

  • Akwarela / Watercolour
    • Jacek Krenz
    2019

    katalog dorocznej wystawy Stowarzyszenia Akwarelistów Polskich prezentowanej w Galerii Muzeum regionalnego w Radomsku oraz w Muzeum Miasta Turku im. J. Mehoffera 11.2019. Stowarzyszenie Akwarelistów Polskich 2019,

  • Akwarelą pod strzechy. Krenz J.: Cykl 5 akwarel.
    • Jacek Krenz
    2019

    Akwarelą pod strzechy. wystawa zbiorowa, poplenerowa Stowarzyszenia Akwarelistów Polskich prezentowana w Muzeum - Kaszubski Park Etnograficzny im. Teodory i Izydora Gulgowskich we Wdzydzach Kiszewskich.

  • Algorytmy roju w modelowaniu MES, czyli jak stado szpaków może pomóc inżynierowi
    • Marek Galewski
    • Michał Mazur
    2019 Pismo PG

    W poprzednich numerach „Pisma PG” prof. Jacek Rumiński przedstawił możliwości i perspektywy rozwoju sztucznej inteligencji (SI), zwłaszcza w kontekście notujących obecnie liczne sukcesy sztucznych sieci neuronowych. Jednak nie tylko budowa układu nerwowego jest inspiracją dla nowych metod SI. Ciekawą grupą metod są algorytmy wzorujące się na zachowaniu zwierząt, zwłaszcza na ich zdolnościach socjalnych i współpracy przy stawianiu czoła napotykanym przeciwnościom. Okazuje się, że inspiracje te mogą się przydać np. do ulepszania modeli wykorzystywanych w klasycznych metodach obliczeniowych, takich jak choćby stosowana w inżynierii mechanicznej (i nie tylko) Metoda Elementów Skończonych.

  • Alternative methods for dark fermentation course analysis
    • Edyta Słupek
    • Karolina Kucharska
    • Jacek Gębicki
    2019 Full text SN Applied Sciences

    Dark fermentation course analysis is crucial, as complexed matrix of gaseous components may be formed and revealed during the process. The paper considers key issues related to the microbiological process in which complex organic substances are transformed into hydrogen. For the purposes of hydrogen generation, the application of wastewater mixed sludge pre-treated according to Faloye method (Faloye et al. in Int J Hydrog Energy 38:11765–11773, 2013. https://doi.org/10.1016/j.ijhyd ene.2013.06.129; Int J Hydrog Energy 39:5607–5616, 2014. https ://doi.org/10.1016/j.ijhydene.2014.01.163) was applied. The main risk of by-product formation is related to the presence of methanogens, i.e., Archea, in the sludge. The application of gaseous chromatography confirmed the presence of hydrogen during the initial, lag and log phases of the culture and methane in the late logarithmic death phase of the culture. However, other fermen-tation gaseous products’ presence was not confirmed, as their concentration was under the limit of detection. Therefore, a revision regarding the application of matrix sensors was proposed, and the levels of gases able to be measured using both gas chromatography and matrix sensors were conducted. The criteria of matrix sensors’ selection should include the selectivity not only for the hydrogen, hydrogen sulfide or methane, but also the sensitivity to the response of other gases contained in the mixture—ammonium, carbon dioxide and oxygen. A comprehensive combination of commer-cially available sensors and their applicability for the purposes of dark fermentation course analysis was presented on the basis of the levels of gas concentrations in the generated gas mixture.

  • Alternative treatment approaches of urinary tract infections caused by uropathogenic Escherichia coli strains
    • Beata Zalewska-Piątek
    • Rafał Piątek
    2019 Full text Acta Biochimica Polonica

    Urinary tract infections (UTIs) are the most widespread and annoying infections affecting millions of people every year annually. The biggest problem of urinary diseases are recurrences, the increasing resistance of uropathogens to commonly used antibiotics, as well as the high health care costs of afflicted persons. Uropathogenic Escherichia coli strains (UPECs) are the most dominant etiologic agent of community-acquired infections of this type. During UTI pathogenesis, UPECs utilize various virulence factors, especially mono- and polyadhesive appendages of the chaperone-usher secretion pathway (CUP) required for adhesion, invasion and biofilm formation. The commonly used antibiotics for UTI treatment are usually effective, but their long-term utility may affect the gut microbiota of treated individuals and cause a selection of drug resistant uropathogenic variants. Due to the increasing resistance of UPEC strains to antibiotics via the evolution of specific defense mechanisms there is a need to develop alternative methods and therapeutic strategies to fight UTIs (vaccines, receptor analogues, pilicides and curlicides, bacterial interference or phagotherapy). Such therapeutic approaches usually target the processes enabling uropathogens to survive within urinary tract and cause recurrent infections.

  • Aluminium in glacial meltwater demonstrates an association with nutrient export (Werenskiöldbreen, Svalbard)
    • Łukasz Stachnik
    • Jacob C. Yde
    • Adam Nawrot
    • Łukasz Uzarowicz
    • Elżbieta Łepkowska
    • Katarzyna Kozak
    2019 HYDROLOGICAL PROCESSES

    The aluminium (Al) cycle in glacierised basins has not received a great deal of attention in studies of biogeochemical cycles. As Almay be toxic for biota, it is important to investigate the processes leading to its release into the environment. It has not yet been ascertained whether filterable Al (passing through a pore size of 0.45 m) is incorporated into biogeochemical cycles in glacierised basins. Our study aims to determine the relationship between the processes bringing filterable Al and glacier-derived filterable nutrients (particularly Fe and Si) into glacierised basins. We investigated theWerenskiöldbreen basin (44.1 km2, 60% glacierised) situated in SWSpitsbergen, Svalbard. In 2011, we collected meltwater from a subglacial portal at the glacier front and at a downstream hydrometric station throughout the ablation season. The Al concentration, unchanged between the subglacial system and proglacial zone, reveals that aluminosilicate weathering is a dominant source of filterable Al under subglacial conditions. By examining the Al:Fe ratio compared with pH and the sulphate mass fraction index, we found that the proton source for subglacial aluminosilicate weathering ismainly associatedwith sulphide oxidation and, to a lesser degree, with hydrolysis and carbonation. In subglacial outflows and in the glacial river, Al and Fe are primarily in the forms of Al(OH)4 - and Fe(OH)3. The annual filterable Al yield (2.7 mmolm-2)was of amagnitude similar to that of nutrients such as filterable Fe (3.0 mmolm-2) and lower than that of dissolved Si (18.5 mmolm-2). Our results show that filterable Al concentrations in meltwater are significantly correlated to filterable and dissolved glacier-derived nutrients (Fe and Si, respectively) concentrations in glaciers worldwide. We conclude that a potential bioavailable Al pool derived from glacierised basins may be incorporated in biogeochemical cycles, as it is strongly related to the concentrations and yields of glacier-derived nutrients.

  • Amides as models to study the hydration of proteins and peptides — spectroscopic and theoretical approach on hydration in various temperatures
    • Aneta Panuszko
    • Michał Nowak
    • Piotr Bruździak
    • Marcin Stasiulewicz
    • Janusz Stangret
    2019 Full text JOURNAL OF MOLECULAR LIQUIDS

    Interactions with water are one of the key factors which determine protein stability and activity in aqueous solutions. However, the protein hydration is still insufficiently understood. N-methylacetamide (NMA) is regarded as a minimal part of the peptide backbone and the relative simplicity of its structure makes it a good model for studies on protein–water interactions. In this paper, the influence of NMA and N,N-dimethylacetamide (DMA) on surrounding water molecules in a range of temperature (25–75 ◦C) is studied by means of the FTIR spectroscopy. The results of the difference HDO spectra method are compared with the results of theoretical DFT calculations of NMA and DMA aqueous complexes. Both NMA and DMA can be regarded as “structure-makers”, yet their hydration spheres are different. These molecules exhibit a mixed and mutually dependent types of hydration: hydrophilic and hydrophobic. In the case of a NMA molecule that has one methyl group less than DMA, the type of hydrophobic hydration is more important. The DMA hydration sphere is less stable: the interactions between water molecules around the methyl groups are strained. Moreover, the hydration of NMA is much more temperature dependant than in the case of DMA. The source of the differences may be hidden in the N-H· · ·H2O interaction. The delicate nature of water interactions with the peptide block models may be cautiously translated into the much more complicated interactions of proteins with their hydration shells.

  • Amyloid fibril formation in the presence of water structure-affecting solutes
    • Jarosław Wawer
    • Emilia Kaczkowska
    • Jakub Karczewski
    • Marcin Olszewski
    • Danuta Augustin-Nowacka
    • Joanna Krakowiak
    2019 BIOPHYSICAL CHEMISTRY

    The impact of the differently hydrated non-electrolytes (protein structure destabilizers) on the fibrillation of hen egg white lysozyme (HEWL) was investigated. Two isomeric urea derivatives i.e. butylurea (BU) and N,N,N′,N′-tetramethylurea (TMU) were chosen as a tested compounds. The obtained results show that butylurea exerts greater impact on HEWL and its fibrillation than tetramethylurea. Both substances decrease the time of induction of the fibrillation (lag time) but only BU increases the efficiency of amyloidogenesis. For the systems with equivalent reduction of the HEWL stability (250 mM BU and 500 mM TMU) the not-equivalent increase of the protein fibrillation was recorded (higher for BU). This fact suggests that specific interactions with protein, possibly water mediated, are responsible for the action of the tested substances.

  • An Analysis of Neural Word Representations for Wikipedia Articles Classification
    • Julian Szymański
    • Nathan Kawalec
    2019 CYBERNETICS AND SYSTEMS

    One of the current popular methods of generating word representations is an approach based on the analysis of large document collections with neural networks. It creates so-called word-embeddings that attempt to learn relationships between words and encode this information in the form of a low-dimensional vector. The goal of this paper is to examine the differences between the most popular embedding models and the typical bag-of-words (BoW) approach used for document representation. The hypothesis behind the experiments is that the more informative the representation is, the better classification results it produces. The evaluation of the representations has been performed with regards to the accuracy of three text classifiers. The experiments have been performed on subsets of articles selected from Wikipedia. To test the independence of the results from the language of their dataset, we created datasets for the Polish and English versions of this repository. The datasets have been provided publicly to create a baseline to study the different representation methods. The classification tasks, which aim to reconstruct the human-made Wikipedia categories, confirm that the word embeddings can be successfully used for text classification. Word embeddings for document representation with typical vector averaging methods does not outperform usage of BoW. We use a modification of the document representation based on kernel transformations that shows an improvement of the text classification results. Also, we find that in most cases the method of dimensionality reduction with neural embeddings outperforms that of LSA.

  • An Attempt to Create Speech Synthesis Model That Retains Lombard Effect Characteristics
    • Grazina Korvel
    • Olga Kurasova
    • Bożena Kostek
    2019 Full text

    The speech with the Lombard effect has been extensively studied in the context of speech recognition or speech enhancement. However, few studies have investigated the Lombard effect in the context of speech synthesis. The aim of this paper is to create a mathematical model that allows for retaining the Lombard effect. These models could be used as a basis of a formant speech synthesizer. The proposed models are based on dividing the speech signal into harmonics and modeling them as the output of a SISO system whose transfer function poles are multiple, and inputs vary in time. An analysis of the Lombard effect of the synthesized signal is performed on the noise residual. The synthesized signal residual is described by vectors of acoustic parameters related to the Lombard effect. For testing the performance of the created models in various noise conditions two classifiers are employed, namely kNN and Naive Bayes. For comparison of results, we created models of sinusoids based on frequency tracks. The results show that a model based on the residual sinewave sum demonstrates the possibility of retaining the Lombard effect. Finally, future work directions are outlined in conclusions.

  • An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea
    • Paweł Ziółkowski
    • Janusz Badur
    • Piotr Ziółkowski
    2019 ENERGY

    In this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and mixed with additional air. The efficiency gain is dependent on the extraction intermediate pressure and the extraction mass flow rate. The mathematical model of the proposed cycle and its implementation in an in-house code termed COM-GAS is presented. This zero-dimensional robust model allows the prediction of basic parameters such as temperatures, combustion composition, efficiency, and other related factors. Numerical simulations of both basic models with either semi-perfect or real gases based on thermodynamic tables were compared with available exploited data, and differences between this study and others did not exceed 5%. Contrarily, differences between gas turbine cycle with regenerative heating are visible between the two models. In particular, when using the coupled classical regeneration with regeneration according to Szewalski's idea, the integrated cycle efficiency could be significantly increased up to 39.5%.