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Gdańsk University of Technology

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Publications from the year 2020

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  • A Parallax Shift Effect Correction Based on Cloud Height for Geostationary Satellites and Radar Observations
    • Tomasz Bieliński
    2020 Full text Remote Sensing

    The effect of cloud parallax shift occurs in satellite imaging, particularly for high angles of satellite observations. This study demonstrates new methods of parallax effect correction for clouds observed by geostationary satellites. The analytical method that could be found in literature, namely the Vicente et al./Koenig method, is presented at the beginning. It approximates a cloud position using an ellipsoid with semi-axes increased by the cloud height. The error values of this method reach up to 50 meters. The second method, which is proposed by the author, is an augmented version of the Vicente et al./Koenig approach. With this augmentation, the error can be reduced to centimeters. The third method, also proposed by the author, incorporates geodetic coordinates. It is described as a set of equations that are solved with the numerical method, and its error can be driven to near zero by adjusting the count of iterations. A sample numerical solution procedure with application of the Newton method is presented. Also, a simulation experiment that evaluates the proposed methods is described in the paper. The results of an experiment are described and contrasted with current technology. Currently, operating geostationary Earth Observation (EO) satellite resolutions vary from 0.5 km up to 8 km. The pixel sizes of these satellites are much greater than for maximal error of the least precise method presented in this paper. Therefore, the chosen method will be important when the resolution of geostationary EO satellites reaches 50 m. To validate the parallax correction, procedure data from on-ground radars and the Meteosat Second Generation (MSG) satellite, which describes stormy events, was compared before and after correction. Comparison was performed by correlating the logarithm of the cloud optical thickness (COT) with radar reflectance in dBZ (radar reflectance – Z in logarithmic form).

  • A pilot study to assess an in-process inspection method for small diameter holes produced by Direct Metal Laser Sintering
    • Mariusz Deja
    • Dawid Zieliński
    2020 Full text RAPID PROTOTYPING JOURNAL

    Purpose The purpose of this research is to evaluate the geometric quality of small diameter holes in parts printed by DMLS technology. An in-process optical inspection method is proposed and assessed during a pilot study. The influence of the theoretical hole diameter assumed in a CAD system and the sample thickness (hole length) on the hole clearance was analysed. Design/methodology/approach The samples made of two different materials: EOS MaragingSteel MS1 and aluminium alloy EOS Aluminium consisted of straight through holes of different diameters and lengths. Dimensional and shape accuracy of the holes were determined with the use of the image processing software and the computer analysis of 2-D images. The definition of the equivalent hole diameter was proposed to calculate the hole clearance. Feret’s diameters were determined for the evaluation of the shape accuracy. Findings The dependency between the equivalent hole diameter and the theoretical diameter was approximated by the linear function for a specific sample thickness. Additionally, a general empirical model for determining the hole clearance was developed, allowing for calculating the equivalent hole diameter as a function of a sample thickness and a theoretical hole diameter. Practical implications Developed functions can be used by designers for a proper assignment of a hole diameter to achieve the required patency. The relevant procedures and macros based on proposed empirical models can be embedded in CAD systems to support the designing process. Originality/value The analysis of the geometric quality of the holes in parts printed by DMLS was based on the computer analysis of 2-D images. The proposed method of assessing the shape accuracy of straight through holes is relatively cheap, is widely available and can be applied to the features of other shapes produced by 3D printing.

  • A Population-Based Method with Selection of a Search Operator
    • Krystian Łapa
    • Krzysztof Cpałka
    • Tacjana Niksa-Rynkiewicz
    • Wang Lipo
    2020

    This paper presents a method based on a population in which the parameters of individuals can be processed by operators from various population-based algorithms. The mechanism of selecting operators is based on the introduction of an additional binary parameters vector located in each individual, on the basis of which it is decided which operators are to be used to modify individuals’ parameters. Thus, in the proposed approach, many operators can be used simultaneously for this purpose. As part of the paper various methods of initializing binary parameters, various population sizes, and their impact on the operation of the algorithm were tested. The simulation was carried out on a wellknown set of benchmark functions.

  • A pore-scale thermo–hydro-mechanical model for particulate systems
    • Robert Caulk
    • Luc Sholtès
    • Marek Krzaczek
    • Bruno Chareyre
    2020 COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING

    A pore scale numerical method dedicated to the simulation of heat transfer and associated thermo–hydro-mechanical couplings in granular media is described. The proposed thermo–hydro-mechanical approach builds on an existing hydromechanical model that employs the discrete element method for simulating the mechanical behavior of dense sphere packings and combines it with the finite volume method for simulating pore space fluid flow and the resulting hydro-mechanical coupling. Within the hydro-mechanical framework, the pore space is discretized as a tetrahedral network whose geometry is defined by the triangulation of discrete element method (DEM) particle centers. It is this discretization of DEM particle contacts and tetrahedral pore spaces that enables the efficient conductive and advective heat transfer models proposed herein. In particular, conductive heat transfer is modeled explicitly between and within solid and fluid phases: across DEM particle contacts, between adjacent tetrahedral pores, and between pores and incident particles. Meanwhile, advective heat transfer is added to the existing implicit fluid flow scheme by estimating mass–energy–flux from pressure induced fluid fluxes. In addition to the heat transfer model, a thermo-mechanical coupling is implemented by considering volume changes based on the thermal expansion of particles and fluid. The conduction and advection models are verified by presenting comparisons to an analytical solution for conduction and a fully resolved numerical solution for conduction and advection. Finally, the relevance of the fully coupled thermo–hydro-mechanical model is illustrated by simulating an experiment where a saturated porous rock sample is subjected to a cyclic temperature loading.

  • A Power-Efficient Digital Technique for Gain and Offset Correction in Slope ADCs
    • Miron Kłosowski
    2020 Full text IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    In this brief, a power-efficient digital technique for gain and offset correction in slope analog-to-digital converters (ADCs) has been proposed. The technique is especially useful for imaging arrays with massively parallel image acquisition where simultaneous compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. The presented approach is based on stopping the ADC clock by a specially prepared clock-enable pulse sequence. This brief describes the properties of ADCs utilizing this clock stopping technique, including power dissipation, integral, and differential nonlinearity. The experimental validation has been performed for the ASIC implementation of the 128-pixel imager containing photo-sensors integrated with ADCs. Finally, a modification is proposed that increases the accuracy of the gain correction. Measurements confirm functionality of the proposed approach. Reduction of the PRNU (to ~0.4 LSB) has been achieved as well.

  • A Preliminary Study and Analysis of Tidal Stream Generators
    • Saad bin Abul Kashem
    • Molla E. Majid
    • Mujahid Tabassum
    • Azad Ashraf
    • Jarosław Guziński
    • Krzysztof Łuksza
    2020 Full text Acta Energetica

    For a sustainable future, tidal energy can play a vital role. Tidal energy relies on the gravitational pull of the Moon and the Sun along with the centrifugal forces created by the Earth. Tidal barrage uses the potential energy from the tide and has been very successful in electricity production. With the help of a turbine, kinetic energy can also be harnessed from tidal currents to generate electricity. However, it is not economically feasible to use this type of technology for large scale production of electrical energy. It is important to note that the development of this technology is still in the early stage. This research paper provides a preliminary discussion of tidal energy generation using a few different technologies. Initial research has been done using Computational Fluid Dynamics and SolidWorks software on the tidal stream generator and tidal barrage system. Some of the key challenges are also identified in terms of the development of the tidal energy conversion system.

  • A Proposed Machine Learning Model for Forecasting Impact of Traffic-Induced Vibrations on Buildings
    • Anna Jakubczyk-Gałczyńska
    • Robert Jankowski
    2020

    Traffic-induced vibrations may cause various damages to buildings located near the road, including cracking of plaster, cracks in load-bearing elements or even collapse of the whole structure. Measurements of vibrations of real buildings are costly and laborious. Therefore the aim of the research is to propose the original numerical algorithm which allows us to predict, with high probability, the nega-tive dynamic impact of traffic-induced vibrations on the examined building. The model has been based on machine learning. Firstly, the experimental tests have been conducted on different buildings using specialized equipment taking into ac-count six factors: distance from the building to the edge of the road, type of sur-face, condition of road surface, condition of the building, the absorption of soil and the type of vehicle. Then, the numerical algorithm based on machine learning (using support vector machine) has been created. The results of the conducted analysis clearly show that the method can be considered as a good tool for pre-dicting the impact of traffic-induced vibrations on buildings, being characterized by high reliability.

  • A Proposed Soft Computing Model for Ultimate Strength Estimation of FRP-Confined Concrete Cylinders
    • Reza Kamgar
    • Hosein Naderpour
    • Houman Ebrahimpour Komeleh
    • Anna Jakubczyk-Gałczyńska
    • Robert Jankowski
    2020 Full text Applied Sciences-Basel

    In this paper, the feed-forward backpropagation neural network (FFBPNN) is used to propose a new formulation for predicting the compressive strength of fiber-reinforced polymer (FRP)-confined concrete cylinders. A set of experimental data has been considered in the analysis. The data include information about the dimensions of the concrete cylinders (diameter, length) and the total thickness of FRP layers, unconfined ultimate concrete strength, ultimate confinement pressure, ultimate tensile strength of the FRP laminates and the ultimate concrete strength of the concrete cylinders. The confined ultimate concrete strength is considered as the output data, while other parameters are considered as the input data. These parameters are mostly used in existing FRP-confined concrete models. Soft computing techniques are used to estimate the compressive strength of FRP-confined concrete cylinders. Finally, a new formulation is proposed. The results of the proposed formula are compared to the existing methods. To verify the proposed method, results are compared with other methods. The results show that the described method can forecast the compressive strength of FRP-confined concrete cylinders with high precision in comparison with the existing formulas. Moreover, the mean percentage of error for the proposed method is very low (3.49%). Furthermore, the proposed formula can estimate the ultimate compressive capacity of FRP-confined concrete cylinders with a different type of FRP and arbitrary thickness in the initial design of practical projects.

  • A Rapid and Simple Method for Screening Microorganisms with a Potential for Catechol Biodegradation
    • Natalia Filipowicz
    • Hubert Cieśliński
    2020 International Journal of Environmental Research

    Catechol is a highly toxic compound that is also a key intermediate in biodegradation pathways of various aromatic compounds. In this paper, a new screening method for isolation of microorganisms with the potential for catechol biodegradation is reported. The method described is based on the ability of catechol to form a color complex with Fe3+ ions. For this purpose, basal medium that is widely used for classification of microorganisms by carbon requirements was used. Specifically, minimal Bushnell Haas medium plates supplemented with catechol at 500 mg l−1 concentration were used for both yeast and bacteria cultivation. After appearance of microorganism colonies on the growth medium, each plate was flooded with 7.0 ml of 5% (w/v) of FeCl3 and incubated for a period of 5 min at room temperature. Flooding with this solution led to the formation of a green color from Fe3+-catechol complexes in the growth medium and an appearance of clear zones around colonies of microorganisms that utilize catechol as a sole source of carbon. Based on this, the presented method could be useful as a screening step for microorganisms with a potential for catechol biodegradation.

  • A rapid dispersive liquid–liquid microextraction of antimicrobial onion organosulfur compounds in animal feed coupled to gas chromatography-mass spectrometry
    • Marta Pastor-belda
    • Natalia Arroyo-manzanares
    • Kateryna Yavir
    • Paloma Abad
    • Natalia Campillo
    • Manuel Hernandez-Cordoba
    • Pilar Vinas
    2020 Analytical Methods

    A rapid analytical procedure is proposed for determining two antimicrobial onion organosulfur compounds, propyl disulfide (PDS) and propyl propane thiosulfonate (PTSO), in animal feed. The use of PTSO as a natural ingredient in animal feed is allowed due to its antimicrobial activity against pathogenic organisms. Two analytical methodologies using gas chromatography coupled to mass spectrometry (GC-MS) are compared. After the extraction of the compounds from animal feed with acetonitrile, dispersive solid phase extraction (DSPE) as a cleaning stage with C18, or dispersive liquid–liquid microextraction (DLLME), using 100 mL of CHCl3, was tried. Both the methods were validated using a pig feed sample and the best results were achieved by DLLME. This technique provided cleaner extracts, five-times greater linear ranges and lower detection limits than simple cleaning due to the enrichment factor achieved. The relative standard deviation decreased from 22% with DSPE to 13% with DLLME. The usefulness of the DLLME-GC-MS methodology was tested by analysing 10 different samples of chicken, calf, hen, cow and fish feed. The concentrations of PDS were in the 0.1–1.7 mg g1 range and those of PTSO were between 0.09 and 2.1 mg g-1

  • A reactive algorithm for deducing nodal forwarding behavior in a multihop ad-hoc wireless network in the presence of errors
    • Karol Rydzewski
    • Jerzy Konorski
    2020 Full text International Journal of Electronics and Telecommunications

    A novel algorithm is presented to deduce individual nodal forwarding behavior from standard end-to-end acknowledgments. The algorithm is based on a well-established mathematical method and is robust to network related errors and nodal behavior changes. The proposed solution was verified in a network simulation, during which it achieved sound results in a challenging multihop ad-hoc network environment.

  • A Review of Emotion Recognition Methods Based on Data Acquired via Smartphone Sensors
    • Agata Kołakowska
    • Wioleta Szwoch
    • Mariusz Szwoch
    2020 Full text SENSORS

    In recent years, emotion recognition algorithms have achieved high efficiency, allowing the development of various affective and affect-aware applications. This advancement has taken place mainly in the environment of personal computers offering the appropriate hardware and sufficient power to process complex data from video, audio, and other channels. However, the increase in computing and communication capabilities of smartphones, the variety of their built-in sensors, as well as the availability of cloud computing services have made them an environment in which the task of recognising emotions can be performed at least as effectively. This is possible and particularly important due to the fact that smartphones and other mobile devices have become the main computer devices used by most people. This article provides a systematic overview of publications from the last 10 years related to emotion recognition methods using smartphone sensors. The characteristics of the most important sensors in this respect are presented, and the methods applied to extract informative features on the basis of data read from these input channels. Then, various machine learning approaches implemented to recognise emotional states are described.

  • A screening of select toxic and essential elements and persistent organic pollutants in the fur of Svalbard reindeer
    • Aneta Pacyna-Kuchta
    • Paulina Wietrzyk-Pełka
    • Michał Węgrzyn
    • Marcin Frankowski
    • Żaneta Polkowska
    2020 Full text CHEMOSPHERE

    Reindeers play an important role in the polar ecosystem, being long-lived sole vegetarians feeding on local vegetation. They can be used as a valuable bioindicator, helping us to understand contaminants’ impact on the polar terrestrial ecosystem. Still, scarce data exist from research in which polar herbivores (especially those from the European parts of the Arctic) were a major study subject for trace elements and persistent organic pollutant determination. Here, Svalbard reindeer fur has been used to determine metals, non-metals and metalloids using ICP-MS, and several persistent organic pollutants including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) using gas chromatography coupled to a tandem mass spectrometer (GC-MS/MS). Samples were collected from reindeer populations living in the area near Ny-Ålesund and Longyearbyen. Essential elements like Fe, Mg, Zn, K, Ca, Cu predominated in the trace elements profile. Median values of As, Cd, Co, Li, Ni, Se and V were all below 0.5 mg/g dw. Mercury was below detection limit in all samples, while the Pb median varied from 0.35 to 0.74 mg/g dw. Except acenaphthylene and fluorene, PAHs were detectable only in samples collected in the vicinity of Longyearbyen. Of 15 studied pesticides, only DDT and its metabolites were above the detection limit, and, of PCBs, only PCB28.

  • A shear stress micromodel of urinary tract infection by the Escherichia coli producing Dr adhesin
    • Beata Zalewska-Piątek
    • Marcin Olszewski
    • Tomasz Lipniacki
    • Sławomir Błoński
    • Miłosz Wieczór
    • Piotr Bruździak
    • Anna Skwarska
    • Bogdan Nowicki
    • Stella Nowicki
    • Rafał Piątek
    2020 Full text PLoS Pathogens

    In this study, we established a dynamic micromodel of urinary tract infection to analyze the impact of UT-segment-specific urinary outflow on the persistence of E. coli colonization. We found that the adherence of Dr+ E. coli to bladder T24 transitional cells and type IV collagen is maximal at lowest shear stress and is reduced by any increase in flow velocity. The analyzed adherence was effective in the whole spectrum of physiological shear stress and was almost irreversible over the entire range of generated shear force. Once Dr+ E. coli bound to host cells or collagen, they did not detach even in the presence of elevated shear stress or of chloramphenicol, a competitive inhibitor of binding. Investigating the role of epithelial surface architecture, we showed that the presence of budding cells–a model microarchitectural obstacle–promotes colonization of the urinary tract by E. coli. We report a previously undescribed phenomenon of epithelial cell “rolling-shedding” colonization, in which the detached epithelial cells reattach to the underlying cell line through a layer of adherent Dr+ E. coli. This rolling-shedding colonization progressed continuously due to “refilling” induced by the flow-perturbing obstacle. The shear stress of fluid containing free-floating bacteria fueled the rolling, while providing an uninterrupted supply of new bacteria to be trapped by the rolling cell. The progressive rolling allows for transfer of briefly attached bacteria onto the underlying monolayer in a repeating cascading event.

  • A simple model of the trap-assisted recombination with the excitonic Auger mechanism
    • Jędrzej Szmytkowski
    2020 Full text European Physical Journal Plus

    We present a simple model of the trap-assisted recombination combined with the excitonic Auger mechanism. It has been shown that only six independent transitions of electrons and holes should be taken into account to describe a combination of the Shockley–Read–Hall (SRH) recombination with this excitonic process. This is in opposition to a well-known model of the SRH mechanism with the free carriers Auger effect via deep states, where eight separated transitions take place. The derived equation for the effective recombination rate can be useful for modeling the excitonic processes in semiconductors, especially in photovoltaic and optoelectronic devices.

  • A space-efficient algorithm for computing the minimum cycle mean in a directed graph
    • Paweł Pilarczyk
    2020 Journal of Mathematics and Computer Science-JMCS

    An algorithm is introduced for computing the minimum cycle mean in a strongly connected directed graph with n vertices and m arcs that requires O(n) working space. This is a considerable improvement for sparse graphs in comparison to the classical algorithms that require O(n^2) working space. The time complexity of the algorithm is still O(nm). An implementation in C++ is made publicly available at http://www.pawelpilarczyk.com/cymealg/.

  • A strong preference for the TA/TA dinucleotide step discovered for an acridine-based, potent antitumor dsDNA intercalator, C-1305: NMR-driven structural and sequence-specificity studies
    • Tomasz Laskowski
    • Witold Andrałojć
    • Jakub Grynda
    • Paulina Gwarda
    • Jan Mazerski
    • Zofia Gdaniec
    2020 Full text Scientific Reports

    Triazoloacridinone C-1305, a potent antitumor agent recommended for Phase I clinical trials, exhibits high activity towards a wide range of experimental colon carcinomas, in many cases associated with complete tumor regression. C-1305 is a well-established dsDNA intercalator, yet no information on its mode of binding into DNA is available to date. Herein, we present the NMR-driven and MD-refined reconstruction of the 3D structures of the d(CGATATCG)2:C-1305 and d(CCCTAGGG)2:C-1305 non-covalent adducts. In both cases, the ligand intercalates at the TA/TA site, forming well-defined dsDNA:drug 1:1 mol/mol complexes. Orientation of the ligand within the binding site was unambiguously established by the DNA/ligand proton-proton NOE contacts. A subsequent, NMR-driven study of the sequence-specificity of C-1305 using a series of DNA duplexes, allowed us to confirm a strong preference towards TA/TA dinucleotide steps, followed by the TG/CA steps. Interestingly, no interaction at all was observed with duplexes containing exclusively the AT/AT, GG/CC and GA/TC steps.

  • A Study of Cross-Linguistic Speech Emotion Recognition Based on 2D Feature Spaces
    • Gintautas Tamulevicius
    • Grazina Korvel
    • Anil Bora Yayak
    • Povilas Treigys
    • Jolita Bernataviciene
    • Bożena Kostek
    2020 Full text Electronics

    In this research, a study of cross-linguistic speech emotion recognition is performed. For this purpose, emotional data of different languages (English, Lithuanian, German, Spanish, Serbian, and Polish) are collected, resulting in a cross-linguistic speech emotion dataset with the size of more than 10.000 emotional utterances. Despite the bi-modal character of the databases gathered, our focus is on the acoustic representation only. The assumption is that the speech audio signal carries sufficient emotional information to detect and retrieve it. Several two-dimensional acoustic feature spaces, such as cochleagrams, spectrograms, mel-cepstrograms, and fractal dimension-based space, are employed as the representations of speech emotional features. A convolutional neural network (CNN) is used as a classifier. The results show the superiority of cochleagrams over other feature spaces utilized. In the CNN-based speaker-independent cross-linguistic speech emotion recognition (SER) experiment, the accuracy of over 90% is achieved, which is close to the monolingual case of SER.

  • A study of the kinetics of bismuth telluride synthesis by an oxide reduction method
    • Bartosz Jakub Trawiński
    • Beata Bochentyn
    • Marcin Stanisław Łapiński
    • Bogusław Kusz
    2020 Full text THERMOCHIMICA ACTA

    The kinetics of a reduction of bismuth and tellurium oxides in a hydrogen atmosphere, leading to the formation of thermoelectric bismuth telluride is investigated. The evaluation of the reaction kinetics was based on a thermogravimetric analysis performed in non-isothermal conditions. A non-parametric analysis method and the Friedman method were used for the evaluation of the data. Additionally, for a better understanding of the process, reactions of the reduction of Bi2O3, TeO2 as well as Bi2Te2O7 and Bi2Te4O11, which are formed as intermediate products, were investigated. The activation energies calculated for the reactions were between 56 kJ/mol in the case of the Bi2Te2O7 reduction and 100 kJ/mol for the reduction of mixed oxides. No correlation between the activation energy and the Bi:Te ratio in the reduced material was found. The calculated conversion functions also differed between the investigated reactions. A self-heating process was found for TeO2 and Bi2Te4O11 reduction reactions. In the case of the tellurium oxide, it was assigned to the melting of Te nanoparticles. These effects were also found to enhance the synthesis of Bi2Te3 by the reduction of mixed bismuth and tellurium oxides. The resulting thermoelectric material was found to be completely reduced, with no traces of oxygen in the XPS spectrum. EDX mapping of the cross-section of material’s grains revealed a homogenous distribution of elements in the final product.

  • A study on fibre-reinforced concrete elements properties based on the case of habitat modules in the underwater sills
    • Marzena Kurpińska
    • Beata Grzyl
    • Adam Kristowski
    2020 Full text Polish Maritime Research

    Hydrotechnical constructions are mostly objects functioning in extreme conditions and requiring a custom-made construction project. In the case of using prefabricated elements, it is required to develop production, transport, assembly, conservation and repair technology. Concerning the problem of concrete cracks, modern repair systems allow positive effects to be achieved in many cases of concrete elements repair. In this work an attempt has been made to assess the properties of concrete, situated in the Baltic Sea environment, in which traditional rebar was partly replaced by dispersed fibre-phase. Fibre-reinforced concrete belongs to the group of composite materials. The presence of fibres helps to increase the tensile strength, flexural strength and resilience and also prevents the appearance of cracks. In the given paper we will also discuss basic parameters of steel and polymer fibres and the influence of both types of fibres on the maturing and hardened concrete. In this work special attention has been paid to the advantages of polypropylene and polymer fibres with regard to commonly-known steel fibres. The use of synthetic fibres will be advantageous in constructions where the reduction of shrinkage cracks and high resilience are essential. On top of that, the use of synthetic fibres is highly recommended when constructing objects that will be exposed to the impact of an aggressive environment. Undoubtedly, polymer fibres are resistant to the majority of corrosive environments. Fibre-reinforced concretes are a frequently implemented construction solution. The possibility of concrete modification allows the emergence of new construction materials with improved physical-mechanical properties, under the condition of being applied relevantly.