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Gdańsk University of Technology

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  • Analysis of the Dynamic Height Distribution at the Estuary of the Odra River Based on Gravimetric Measurements Acquired with the Use of a Light Survey Boat—A Case Study
    • Jerzy Pyrchla
    • Krzysztof Pyrchla
    • Paulina Kowalska
    • Arkadiusz Tomczak
    • Grzegorz Zaniewicz
    2020 Full text SENSORS

    LaCoste) for determining the dynamic height along the Odra River, in northwest Poland. The gravity measurement campaign described in this article was conducted on a small, hybrid-powered survey vessel (overall length: 9.5 m). We discuss a method for processing the results of gravimetric measurements performed on a mobile platform affected by strong external disturbances. Because measurement noise in most cases consists of signals caused by non-ideal observation conditions, careful attempts were made to analyze and eliminate the noise. Two different data processing strategies were implemented, one for a 20 Hz gravity data stream and another for a 1 Hz data stream. A comparison of the achieved results is presented. A height reference level, consistent for the entire estuary, is critical for the construction of a safe waterway system, including 3D navigation with the dynamic estimation of under-keel clearance on the Odra and other Polish rivers. The campaign was conducted in an area where the accuracy of measurements (levelling and gravimetric) is of key importance for shipping safety. The shores in the presented area of interest are swampy, so watercraft-based measurements are preferred. The method described in the article can be successfully applied to measurements in all near-zero-depth areas.

  • Analysis of the radiation dose in UV-disinfection flow reactors.
    • Wojciech Artichowicz
    • Aneta Łuczkiewicz
    • Jerzy Sawicki
    2020 Full text Water

    Theoretical considerations devoted to the variation of UV radiation doses in flow disinfection reactors are presented. The minimal time required by the fluid to pass the reactor was determined and combined with the radiation intensity. The active zones of the reactor were determined.

  • Analysis of the Ways to Identify Rail Running Surface Defects by Means of Vibration Signals
    • Roksana Licow
    • Franciszek Tomaszewski
    2020 Full text Problemy Kolejnictwa

    Th e article discusses a preliminary concept of a method enabling the identifi cation of chosen rail running surface defects, such as squats, spalling, and running surface defects, by analysing the parameters of vibration signals. It features a description of the methodology of the conducted tests, the scope thereof, and the selection of the measurement points with specifi c defect types. Th e article covers selected results of vibration tests, the results of analyses of recorded signals for defective track sections and those for control track sections. Th e presented measurement results have been obtained for the technical–operating conditions occurring on railway line no. 213 Reda – Hel and line no. 131 Chorzów Batory – Tczew. Th e preliminary test results and conclusions included in the article show that it is reasonable to pursue further research into the phenomena involving the utilisation of vibroacoustics in rail performance diagnostics.

  • Analysis of ultimate compressive strength of cracked plates with the use of DOE techniques
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2020 Full text Polish Maritime Research

    The objective of this work is to investigate the structural compressive response of plates with locked cracks accounting for all relevant factors and correlation between them. The nonlinear FE model considering both geometric and material nonlinearities is employed herein, and the FE model of the structural response of intact plates is validated with the available experimental data. In the common studies, based on One Factor at a Time analysis, some of the parameters and interactions between them are excluded. In the present study, the numerical investigations are conducted with the use of the Design of Experiments techniques, where all essential parameters and their interactions are adequately considered. With a total of 32 numerical analyses, the most influential factors and their interactions are identified. As a study outcome, empirical formulations, which allow for a fast estimation of the ultimate compressive strength of intact plates, plates with locked cracks, and repaired cracked plates, are derived. The developed formulations represent a fast and practical tool for estimating the ultimate compressive strength of intact, cracked, and repaired plates, which can be easily employed in the reliability analysis.

  • Analysis of Validation and Simplification of Timber-Frame Structure Design Stage with PU-Foam Insulation
    • Marcin Szczepański
    • Wojciech Migda
    2020 Full text Sustainability

    The transition from experimental studies to the realm of numerical simulations is often necessary for further studies, but very difficult at the same time. This is especially the case for extended seismic analysis and earthquake-resistant design. This paper describes an approach to moving from the experimental testing of an elementary part of a wood-frame building structure to a numerical model, with the use of a commercial engineering analysis software. In the presented approach, a timber-frame structure with polyurethane (PU)-foam insulation and OSB (oriented strand board) sheathing was exposed to dynamic excitation. The results were then used to generate a numerical 3D model of the wooden frame element. The process of creating the 3D model is explained with the necessary steps to reach validation. The details of the model, material properties, boundary conditions, and used elements are presented. Furthermore, the authors explain the technical possibilities for simplifying the numerical model in used software. Simplifying the model leads to a substantial reduction of calculation time without the loss of accuracy of results. Such a simplification is especially useful when conducting advanced numerical calculations in the field of seismic and dynamic resistant object design.

  • Analysis of Vibration and Acoustic Signals for Noncontact Measurement of Engine Rotation Speed
    • Shan Xuansheng
    • Tang Lu
    • He Wen
    • Radek Martinek
    • Janusz Smulko
    2020 Full text SENSORS

    The non-contact measurement of engine speed can be realized by analyzing engine vibration frequency. However, the vibration signal is distorted by harmonics and noise in the measurement. This paper presents a novel method for the measurement of engine rotation speed by using the cross-correlation of vibration and acoustic signals. This method can enhance the same frequency components in engine vibration and acoustic signal. After cross-correlation processing, the energy centrobaric correction method is applied to estimate the accurate frequency of the engine’s vibration. This method can be implemented with a low-cost embedded system estimating the cross-correlation. Test results showed that this method outperformed the traditional vibration-based measurement method.

  • Analytical calculations of scattering lengths for a class of long-range potentials of interest for atomic physics
    • Radosław Szmytkowski
    2020 Full text JOURNAL OF MATHEMATICAL PHYSICS

    We derive two equivalent analytical expressions for an $l$th partial-wave scattering length $a_{l}$ for central potentials with long-range tails of the form % \begin{math} \displaystyle V(r)=-\frac{\hbar^{2}}{2m}\frac{Br^{n-4}}{(r^{n-2}+R^{n-2})^{2}} -\frac{\hbar^{2}}{2m}\frac{C}{r^{2}(r^{n-2}+R^{n-2})}, \end{math} % ($r\geqslant r_{s}$, $R>0$). % For $C=0$, this family of potentials reduces to the Lenz potentials discussed in a similar context in our earlier works [Acta Phys. Pol.\ A 79 (1991) 613 and J.\ Phys.\ A 28 (1995) 7333]. The formulas for $a_{l}$ which we provide in this paper depend on the parameters $B$, $C$ and $R$ characterizing the tail of the potential, on the core radius $r_{s}$, as well as on the short-range scattering length $a_{ls}$, the latter being due to the core part of the potential. The procedure, which may be viewed as an analytical extrapolation from $a_{ls}$ to $a_{l}$, is relied on the fact that the general solution to the zero-energy radial Schr{\"o}dinger equation with the potential given above may be expressed analytically in terms of the \emph{generalized\/} associated Legendre functions.

  • Analyzing and Visualizing Government-Citizen Interactions on Twitter to Support Public Policy-making
    • Rocio Hubert
    • Elsa Estevez
    • Ana Maguitman
    • Tomasz Janowski
    2020 Full text Digital Government: Research and Practice

    Twitter is widely adopted by governments to communicate with citizens. It has become a major source of data for analyzing how governments communicate with citizens and how citizens respond to such communication, uncovering important insights about government-citizen interactions that could be used to support public policy-making. This article presents research that aims at developing a software tool called Twitter Analytics for Government Intelligence and Public Participation (TA4GIP) that applies sentiment analysis and visualization techniques to information collected from Twitter and presents the findings to policy-makers and other non-technical users to facilitate understanding and interpretation. The use of the tool is illustrated through the case study of Twitter communication carried by five government secretaries responsible for health, education, social development, labor, and environment sectors in Mexico, and corresponding citizen responses over a nine-month period. The case study demonstrates that TA4GIP helps identify and analyze relevant aspects of government presence and citizen participation on social media, such as abnormal activity, salient topics being discussed, citizen views about enacted public policies, correlations between types of emotions in responses to particular government announcements, topics that generate polarized reactions from citizens, and many others.

  • Analyzing the Effectiveness of the Brain–Computer Interface for Task Discerning Based on Machine Learning
    • Jakub Browarczyk
    • Adam Kurowski
    • Bożena Kostek
    2020 Full text SENSORS

    The aim of the study is to compare electroencephalographic (EEG) signal feature extraction methods in the context of the effectiveness of the classification of brain activities. For classification, electroencephalographic signals were obtained using an EEG device from 17 subjects in three mental states (relaxation, excitation, and solving logical task). Blind source separation employing independent component analysis (ICA) was performed on obtained signals. Welch’s method, autoregressive modeling, and discrete wavelet transform were used for feature extraction. Principal component analysis (PCA) was performed in order to reduce the dimensionality of feature vectors. k-Nearest Neighbors (kNN), Support Vector Machines (SVM), and Neural Networks (NN) were employed for classification. Precision, recall, F1 score, as well as a discussion based on statistical analysis, were shown. The paper also contains code utilized in preprocessing and the main part of experiments.

  • Analyzing the Impact of Simulated Multispectral Images on Water Classification Accuracy by Means of Spectral Characteristics
    • Krystyna Michałowska
    • Ewa Głowienka
    2020 Full text Geomatics and Environmental Engineering

    Remote sensing is widely applied in examining the parameters of the state and quality of water. Spectral characteristics of water are strictly connected with the dispersion of electromagnetic radiation by suspended matter and the absorp-tion of radiation by water and chlorophyll a and b.Multispectral sensor ALI has bands within the ranges of electromagnetic radia-tion: blue and infrared, absent in sensors such as Landsat, SPOT, or Aster. The main goal of the article was to examine the influence of the presence of these bands on water classification accuracy carried out for simulated images ALI, Landsat, Spot, and Aster. The simulation of images was based on the hyper-spectral image from a Hyperion sensor. Due to the spectral properties of water, all the operations on the images were carried out for the set of bands in visible and near-infrared (VNIR) spectral range. In the framework of these studies, the impact of removing individual bands or sets of bands on the classification results was tested. Tests were carried out for the area of the water body of the Dobczyce Reservoir. It was observed that the lack of a spectral response in the infrared range of ALI image can reduce the accuracy of a classification by as much as 60%. On the other hand, the lack of blue and red bands in the data-set for the classification decreased the accuracy of water classification by 15% and 10%, respectively.

  • ANALYZING TITLES OF ECONOMY NEWS TO UNDERSTAND IMPACT OF COVID-19 ON ECONOMICAL SITUATION
    • Olgun Aydin
    • Cansu Altunbas
    • Elvan Hayat
    2020

    Covid-19 affected the whole world in a short time, causing serious panic and uncertainty in society. Because it was an unprecedented disease, the medical community has worked hard to find out how to deal with it, and it continues to do so. The rapid spread of the disease, the shortage of hospital capacity and the increase in deaths drove the whole world to a closure, so to speak. In this time period, life in the world came to a halt. This also brought along many problems in terms of global economy. Many businesses announced their bankruptcy, many people were unemployed. Although the governments launched support packages, the lockdown caused huge damage to the global economy. In the light of this information, while studies continue intensively in the fields of medicine, chemistry and biology, researchers have accelerated their studies in fields such as data science, data analysis and open data as well. Within the scope of this study, in order to monitor and analyze the effects of Covid-19 on the economy, the economy news titles in the relevant period were collected and analyzed in detail using text mining techniques, and it was aimed to propose an alternative perspective to analyze the effect of the virus on the global economy.

  • Anodic titania nanotubes decorated with gold nanoparticles produced by laser-induced dewetting of thin metallic films
    • Katarzyna Grochowska
    • Nikolay Nedyalkov
    • Jakub Karczewski
    • Łukasz Haryński
    • Gerard Śliwiński
    • Katarzyna Siuzdak
    2020 Full text Scientific Reports

    Herein, we combine titania layers with gold species in a laser-supported process and report a substantial change of properties of the resulting heterostructures depending on the major processing parameters. Electrodes were fabricated via an anodisation process complemented with calcination to ensure a crystalline phase, and followed by magnetron sputtering of metallic films. The obtained TiO2 nanotubes with deposited thin (5, 10 nm) Au films were treated with a UV laser (355 nm) to form Au nanoparticles on top of the nanotubes. It was proven that selected laser working parameters ensure not only the formation of Au nanoparticles, but also simultaneously provide preservation of the initial tubular architecture, while above-threshold laser fluences result in partial destruction (melting) of the top layer of the nanotubes. For almost all of the samples, the crystalline phase of the nanotubes observed in Raman spectra was maintained independently of the laser processing parameters. Enhanced photoresponse up to ca 6 mA/cm2 was demonstrated by photoelectrochemical measurements on samples obtained by laser annealing of the 10 nm Au coating on a titania support. Moreover, a Mott–Schottky analysis indicated the dramatically increased (two orders of magnitude) concentration of donor density in the case of a laser-treated Au–TiO2 heterojunction compared to reference electrodes.

  • Antenna Modeling Using Variable-Fidelity EM Simulations and Constrained Co-Kriging
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2020 Full text IEEE Access

    Utilization of fast surrogate models has become a viable alternative to direct handling of fullwave electromagnetic (EM) simulations in EM-driven design. Their purpose is to alleviate the difficulties related to high computational cost of multiple simulations required by the common numerical procedures such as parametric optimization or uncertainty quantification. Yet, conventional data-driven (or approximation) modeling techniques are severely affected by the curse of dimensionality. This is a serious limitation when it comes to modeling of highly nonlinear antenna characteristics. In practice, general-purpose surrogates can be rendered for the structures described by a few parameters within limited ranges thereof, which is grossly insufficient from the utility point of view. This paper proposes a novel modeling approach involving variable-fidelity EM simulations incorporated into the recently reported nested kriging modeling framework. Combining the information contained in the densely sampled low- and sparsely sampled highfidelity models is realized using co-kriging. The resulting surrogate exhibits the predictive power comparable to the model constructed using exclusively high-fidelity data while offering significantly reduced setup cost. The advantages over conventional surrogates are pronounced even further. The presented modeling procedure is demonstrated using two antenna examples and further validated through the application case studies.

  • Anticancer Imidazoacridinone C-1311 is Effective in Androgen-Dependent and Androgen-Independent Prostate Cancer Cells
    • Magdalena Niemira
    • Barbara Borowa-Mazgaj
    • Samuel B. Bader
    • Adrianna Moszyńska
    • Marcin Ratajewski
    • Kaja Karaś
    • Mirosław Kwaśniewski
    • Adam Krętowski
    • Zofia Mazerska
    • Ester M. Hammond
    • Anna Skwarska
    2020 Full text Biomedicines

    Androgen receptor (AR) plays a crutial role in prostate cancer (PCa) development and metastasis. Here, we reported potent anti-PCa activity of a small molecule imidazoacridinone C-1311. In AR-positive PCa cells, C-1311 was found to inhibit the transcriptional activity of AR uncovering a novel mechanism that may be relevant for its anticancer effect. Mechanistically, C-1311 decreased AR binding to prostate-specific antigen (PSA) promoter, reduced PSA protein level, and as shown by transcriptome sequenvcing, down-regulated numerous AR target genes. Importantly, AR-negative PCa cells were also sensitive to C-1311, suggesting a promising efficacy in androgen-independent PCa sub-type. Irrespective of AR status, C-1311 induced DNA damage, arrested cell cycle progression and induced apoptosis. RNA sequencing indicated on the significant differences in transcriptional response to C-1311 between PCa cells. Gene ontology analysis showed that in AR-dependent PCa cells, C-1311 mainly affected DNA damage response pathways. In contrast, in AR-independent PCa cells, C-1311 targeted cellular metabolism and inhibited gene regulating glycolysis and gluconeogenesis. Together, these results indicate that C-1311 warrants further development for the treatment of PCa.

  • Antimony substituted lanthanum orthoniobate proton conductor – structure and electronic properties.
    • Aleksandra Mielewczyk-Gryń
    • Sebastian Wachowski
    • Agnieszka Witkowska
    • Kacper Dzierzgowski
    • Wojciech Skubida
    • Konrad Świerczek
    • Anna Regoutz
    • David J. Payne
    • Stephen Hull
    • Hangfeng Zhang
    • Isaac Abrahams
    • Maria Gazda
    2020 JOURNAL OF THE AMERICAN CERAMIC SOCIETY

    X‐ray and neutron diffraction have been utilized to analyze the crystalline and electronic structure of lanthanum orthoniobate substituted by antimony. Using X‐ray absorption spectroscopy and photoelectron spectroscopy, changes in the electronic structure of the material upon substitution have been analyzed. The structural transition temperature between fergusonite and scheelite phases for 30 mol% antimony substitution was found to be 15 °C. Based on the neutron data, the oxygen nonstoichiometry was found to be relatively low. Moreover, no influence on the position of the valence band maximum was observed. The influence of the protonation on the electronic structure of constituent oxides has been studied. Absorption data show that the incorporation of protonic defects into the lanthanum orthoniobate structure leads to changes in lanthanum electronic structure and a decrease in the density of unoccupied electronic states.

  • Application of 3D printing metal powder technology in the manufacture of components with complex geometries
    • Mariusz Deja
    • Dawid Zieliński
    2020 Full text Mechanik

    The possibilities of using 3D printing powder technologies for making objects with complex geometries were presented. For this purpose, selected examples of elements with different geometries were used, which were built using metal powder methods – DMLS (direct metal laser sintering) / SLM (selective laser melting). Simultaneously, the indicated elements concern those areas of industry where 3D printing technology has been widely used in recent years, i.e. maritime and aerospace industries. Also, the metal 3D printing process was characterized by a description of the particular stages of model building. The directions of further development of the above mentioned 3D printing methods and the areas of possible applications of the 3D printed parts were presented, respectively.

  • Application of Analytic Signal and Smooth Interpolation in Pulse Width Modulation for Conventional Matrix Converters
    • Paweł Szczepankowski
    • Patrick Wheeler
    • Tomasz Bajdecki
    2020 Full text IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    The paper proposes an alternative and novel approach to the PWM duty cycles computation for Conventional Matrix Converters (CMC) fed by balanced, unbalanced or non–sinusoidal AC voltage sources. The presented solution simplifies the prototyping of direct modulation algorithms. PWM duty cycles are calculated faster by the smooth interpolation technique, using only vector coordinates, without trigonometric functions and angles. Both input voltages and output reference voltages are expressed by analytic signals in the proposed direct modulation. Input voltages are represented by the rotating vector collection in the two–dimensional Cartesian coordinate system. All reference output voltages are located inside the triangular surface, named here as the voltage synthesis field, formed by these rotating vectors. A certain degree of reference signals placement freedom allows to maximize the voltage transfer ratio to 0:866 with less switching compared to the Optimum–Venturini direct method. The proposed solution was verified by simulations and experiments for CMC3xk. The comparison with the Optimum–Venturini modulation is included. The proposed PWM duty cycle computation approach can also be applied to multiphase CMC converters for any number of inputs as well as outputs.

  • APPLICATION OF APRIORI ALGORITHM IN THE LAMINATION PROCESS IN YACHT PRODUCTION
    • Tacjana Niksa-Rynkiewicz
    • Michał Landowski
    • Paweł Szalewski
    2020 Full text Polish Maritime Research

    The article specifies the dependence of defects occurring in the lamination process in the production of yachts. Despite great knowledge about their genesis, they cannot be completely eliminated. Authentic data obtained through cooperation with one of the Polish yacht shipyards during the years 2013–2017 were used for the analysis. To perform a simulation, the sample size was observed in 1450 samples, consisting of 6 models of yachts with closed and open deck. Finding the dependence of the occurrence of specific defects will allow for faster procedures and more effective quality control, which will contribute to lower costs. The use of new methods based on artificial intelligence related to Big Data allows for easier observation of dependencies in the complex structure of data from yacht production. The association rules were defined using the algorithm Apriori and define interdependent defects. A number of dependencies were found for the occurrence of production defects not obvious to technologists, but occurring with a high probability of coexistence. The presented research results may allow the planning process of production tasks to be improved.

  • Application of BiOClnBrm photocatalyst to cytostatic drugs removal from water; mechanism and toxicity assessment
    • Patrycja Wilczewska
    • Andrea Elisabeth Natasha Ona
    • Aleksandra Bielicka-giełdoń
    • Anna Malankowska
    • Karol Tabaka
    • Jacek Ryl
    • Filip Pniewski
    • Ewa Siedlecka
    2020 Full text SEPARATION AND PURIFICATION TECHNOLOGY

    The photocatalytic activity of series of BiOClnBrm photocatalysts toward degradation and mineralization of the cytostatic drugs 5-fluorouracil (5-FU) and imatinib mesylate (IMA) both singly and in their mixture under simulated solar and visible light irradiation has been investigated. Screening test revealed that among BiOClnBrm photocatalysts synthesized by a solvothermal method, the one with molar 1.3Cl/0.7Br ratio was the most efficient in 5-FU removal under UV-Vis irradiation. The dose 200 mg L-1 and 6.3 pH were optimal to effective removal of 5-FU. The BiOCl1.3Br0.7 was successfully used to 5-FU and IMA removal singly and in their mixture under simulated solar and visible light irradiation. Scavenging experiments showed that h+ and •O2- were the major oxidative species participated in both drugs degradation. In presence of IMA, 5-FU removal was significantly depressed. In singly drug solutions and in the mixture of drugs, the presence of inorganic ions such as Cl−, SO42−, and NO3- significantly hindered 5-FU photocatalytic degradation, and increased the adsorption of IMA onto the photocatalyst surface in dark phase. The HCO3− anion, Fe3+ and Ag+ cations accelerated the 5-FU removal, while Ca2+ showed no impact on the process. The transformation products of 5-FU and IMA were identified by LC-MS revealing that hydroxylation and oxidation were the main transformation pathways, under the all studied systems. Some of intermediates were indicated for the first time in heterogeneous photocatalysis. The defluorination of 5-FU by the reaction with photogenerated e- was also possible. Furthermore, the alga toxicity assay was investigated using Chlorella vulgaris. A reduction of toxicity in effluents after photocatalytic degradation of both drugs singly and in their mixture was observed.

  • Application of Diffusion Models in the Analysis of Financial Markets: Evidence on Exchange Traded Funds in Europe
    • Ewa Lechman
    • Adam Marszk
    2020 Full text Risks

    Exchange traded funds (ETFs) are financial innovations that may be considered as a part of the index financial instruments category, together with stock index derivatives. The aim of this paper is to explore the trajectories and formulates predictions regarding the spread of ETFs on the financial markets in six European countries. It demonstrates ETFs’ development trajectories with regard to stock index futures and options that may be considered as their substitutes, e.g., in risk management. In this paper, we use mathematical models of the diffusion of innovation that allow unveiling the evolutionary patterns of turnover of ETFs; the time span of the analysis is 2004–2015, i.e., the period of dynamic changes on the European ETF markets. Such an approach has so far rarely been applied in this field of research. Our findings indicate that the development of ETF markets has been strongest in Italy and France and weaker in the other countries, especially Poland and Hungary. The results highlight significant differences among European countries and prove that diffusion has not taken place in all the cases; there are also considerable differences in the predicted development paths.

  • Application of Diversity Combining with RLS Adaptive Filtering in Data Transmission in a Hydroacoustic Channel
    • Agnieszka Czapiewska
    • Ryszard Studański
    • Andrzej Łuksza
    • Andrzej Żak
    2020 Full text SENSORS

    When transmitting data in a hydroacoustic channel under difficult propagation conditions, one of the problems is intersymbol interference (ISI) caused mainly by the effect of multipath propagation. This phenomenon leads to a decrease in transmission parameters, and sometimes completely prevents it. Therefore, we have made an attempt to use diversity combining with Recursive Least Squares (RLS) adaptive filtering to improve the quality of data transmission in a hydroacoustic channel with strong reflections. The method was tested in simulation and during measurements in a real environment. The influence of the method on data transmission in the hydroacoustic channel was examined in detail. The obtained results allow us to draw conclusions regarding the purposefulness of use of diversity combining and RLS adaptive filtering in order to improve the quality of data transmission by reducing the effect of ISI.

  • Application of Least Squares with Conditional Equations Method for Railway Track Inventory Using GNSS Observations
    • Krzysztof Czaplewski
    • Zbigniew Wiśniewski
    • Cezary Specht
    • Andrzej Wilk
    • Władysław Koc
    • Krzysztof Karwowski
    • Jacek Skibicki
    • Paweł Dąbrowski
    • Bartosz Czaplewski
    • Mariusz Specht
    • Piotr Chrostowski
    • Jacek Szmagliński
    • Sławomir Judek
    • Sławomir Grulkowski
    • Roksana Licow
    2020 Full text SENSORS

    Satellite geodetic networks are commonly used in surveying tasks, but they can also be used in mobile surveys. Mobile satellite surveys can be used for trackage inventory, diagnostics and design. The combination of modern technological solutions with the adaptation of research methods known in other fields of science offers an opportunity to acquire highly accurate solutions for railway track inventory. This article presents the effects of work carried out using a mobile surveying platform on which Global Navigation Satellite System (GNSS) receivers were mounted. The satellite observations (surveys) obtained were aligned using one of the methods known from classical land surveying. The records obtained during the surveying campaign on a 246th km railway track section were subjected to alignment. This article provides a description of the surveying campaign necessary to obtain measurement data and a theoretical description of the method employed to align observation results as well as their visualisation.

  • Application of mesh deformation for modeling of conformal RF components with 3D FEM
    • Maciej Jasiński
    • Adam Lamęcki
    • Michał Mrozowski
    2020 Full text

    In this paper, a method of analysis of conformal RF components has been proposed. In this approach, modeling of a curved structure is based on mesh deformation of planar objects rather than the construction of conformal geometry at CSG level. Since the model is represented as a 3D mesh, the deformation only requires the calculation of nodes position in the bent structure. The results of the proposed algorithm have been validated with simulation from other software and measurements, whereby method correctness has been confirmed

  • Application of non-classical operational calculus to indicate hazards in numerical solutions of engineering problems
    • Eligiusz Mieloszyk
    • Mariusz Wyroślak
    2020 Full text Studia Geotechnica et Mechanica

    The article addresses the application of non- classical operational calculus to approximative solutions of engineering problems. The engineering-sound examples show that a continuous–discrete problem transformation from differential unequivocal problem to a differential wildcard problem, triggering a change in solution quality. A number of approximative methods are capable to alter both quantitative and qualitative solution effects.

  • Application of probabilistic tools to extend load test design of bridges prior to opening
    • Piotr Owerko
    • Karol Winkelmann
    • Jarosław Górski
    2020 Structure and Infrastructure Engineering

    Load tests of bridges are widely performed in a large number of countries. Deterministic comparison of measurement results to the theoretical, FEM (finite element method)-based outcomes with possible further calibration is mostly applied. Sometimes, the data collected in the tests are also used to calibrate the reliability factors of bridge structures or their components. This work proposes to complement the stage of the load test design with the use of probabilistic tools. This approach is intended to provide a reliable and trustworthy limit range of measured values (e.g. displacements) instead of restrictive single values, streamlining the performance of in-situ tests. The proposed procedure is supported by an arch bridge example with the following uncertainty sources: random imperfections of the arch girder, random stiffness of the deck and random total weight of the applied load trucks. The presented calculations refer to global structural stiffness assessment. Both point estimate method (PEM) and response surface method (RSM) are applied here. It has been shown that the proposed procedure effectively supplements the deterministic approach, thus the suggested extension of application of probabilistic tools to bridge load test design is innovative and justified.

  • Application of safirinium N-hydroxysuccinimide esters to derivatization of peptides for high-resolution mass spectrometry, tandem mass spectrometry, and fluorescent labeling of bacterial cells
    • Joanna Fedorowicz
    • Magdalena Wierzbicka
    • Marek Cebrat
    • Paulina Wiśniewska
    • Rafał Piątek
    • Beata Zalewska-Piątek
    • Zbigniew Szewczuk
    • Jarosław Sączewski
    2020 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Mass spectrometry methods are commonly used in the identification of peptides and biomarkers. Due to a relatively low abundance of proteins in biological samples, there is a need for the development of novel derivatization methods that would improve MS detection limits. Hence, novel fluorescent N-hydroxysuccinimide esters of dihydro-[1,2,4]triazolo[4,3-a]pyridin-2-ium carboxylates (Safirinium P dyes) have been synthesized. The obtained compounds, which incorporate quaternary ammonium salt moieties, easily react with aliphatic amine groups of peptides, both in solution and on the solid support; thus, they can be applied for derivatization as ionization enhancers. Safirinium tagging experiments with ubiquitin hydrolysate revealed that the sequence coverage level was high (ca. 80%), and intensities of signals were enhanced up to 8-fold, which proves the applicability of the proposed tags in the bottom-up approach. The obtained results confirmed that the novel compounds enable the detection of trace amounts of peptides, and fixed positive charge within the tags results in high ionization efficiency. Moreover, Safirinium NHS esters have been utilized as imaging agents for fluorescent labeling and the microscopic visualization of living cells such as E. coli Top10 bacterial strain.

  • Application of Shape Memory Alloys in Pipeline Couplings for Shipbuilding
    • Leszek Matuszewski
    2020 Full text Polish Maritime Research

    The aim of the study is to analyse shape memory alloy (SMA) pipeline joints in limited space applications for all kinds of ships. Generally, the space available in various areas on ships is strictly limited and service works usually meet many obstacles. If we consider a pipeline, the flange joints always require a larger free space around the pipe than the pipe alone. A simultaneous problem can occur with the propeller shaft line coupling between bearings. SMA couplings require less space around the pipe and service should be easier, e.g., insulation fixing, painting and so on. SMA couplings last for a lifetime and there is no need for periodical seal replacement. Herein, some proposals among other unpublished data are discussed. There is a significant technological interest in the use of SMAs for applications not widely used yet. A wide variety of alloys present the shape memory effect and many generate an expressive restitution force considerable for commercial interests.

  • Application of sliding switching functions in backstepping based speed observer of induction machine
    • Marcin Morawiec
    • Arkadiusz Lewicki
    2020 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    The paper presents an analysis of the speed observer which is based on the backstepping and sliding mode approach. The speed observer structure is based on the extended mathematical model of an induction machine. The observer structure is based on the measured phase stator currents and transformed to ( αβ ) coordinate system. The stator voltage vector components are treated as known values. Additionally, such an observer structure is extended to the integrators. The observer stabilizing functions contain the appropriate sliding surfaces which result from Lyapunov function. The rotor angular speed is obtained from non-adaptive dependence. Stability analysis of the observer structure based on Lyapunov theory is presented in order to guarantee the estimation errors decay to zero.

  • Application of Stirling Engine Type Alpha Powered by the Recovery Energy on Vessels
    • Jacek Kropiwnicki
    2020 Full text Polish Maritime Research

    The Stirling engine is a device, in which thermal energy is transformed into mechanical without a contact between the heat carrier, and the working gas closed in the engine. Mentioned feature makes this type of engine very attractive for the use of the recovery energy, taken from other heat devices. One of the potential applications of Stirling engines is the use of thermal energy generated in the ship's engine room for producing electricity. The work presents the concept of the Stirling engine type alpha powered by the recovery energy. The model of Stirling engine developed in this work allows a quantitative assessment of the impact of the design features of the engine, primarily the heat exchange surfaces and the volume of control spaces, on the achieved efficiency and power of the engine. Using the iterative procedure, the Stirling engine simulation tests were carried out taking into account the variable structural features of the system. The influence of the size of the heater and the cooler, as well as, the effectiveness of the regenerator and the temperature of the heat source on the efficiency and power produced by the Stirling engine have been presented.

  • Application of surface active amino acid ionic liquids as phase-transfer catalyst
    • Emil Szepiński
    • Patrycja Smolarek
    • Maria Milewska
    • Justyna Łuczak
    2020 JOURNAL OF MOLECULAR LIQUIDS

    Five structurally related morpholinium derived ionic liquids containing N-acetyl-glycinate anion were synthesized and their thermal stability, surface properties and activity as phase transfer catalysts investigated. The thermal properties were studied by differential scanning calorimetry, while the adsorption at the air/water interface and micellization behavior was analyzed by surface tension measurements, conductometry and isothermal titration calorimetry. The catalytic activity was assessed in two model reactions that were N-alkylation of dibenzoazepine and C-alkylation reaction of fluorene derivatives. The effect of the chain length, thus surface activity of the newly synthetized ionic liquids on the yields of N- and C-alkylation reactions was discussed.

  • Application of the Anammox Process for Treatment of Liquid Phase Digestate
    • Joanna Majtacz
    • Dominika Grubba
    • Krzysztof Czerwionka
    2020 Full text Water

    The liquid phase of the digestate (LPD) contains a relatively high concentration of nitrogen, with total ammonium nitrogen being the dominant form of nitrogen, as well as other essential nutrients such as phosphorus and potassium. Consequently, it must be treated before it is released into the environment. However, there are no reports of co-purification of LPD in the anammox process in sequencing batch reactor with granular sludge, which is a novelty for the presented research. The main objective of this paper is to assess the possibility of nitrogen removal in the anammox process with LPD from biogas plants conducting the co-fermentation process along with the participation of agricultural products (cattle slurry). This publication presents the research results of the efficiency of the anammox process, accounting for the effect of dissolved organic matter. The conducted experiments revealed the potential of LPD purification, which co-ferments waste activated sludge and bovine slurry for the anammox process. In the reactor ammonium utilization rate (AUR) process with LPD addition increased from 2.3 mg N/(g VSS∙h) with 0.5% LPD addition to 8.5 mg N/(g VSS∙h) with 7.5% LPD addition. SAA in the reactor with LPD addition increased from 5.3 mg N/(g VSS∙h) with 0.5% LPD addition to 18.5 mg N/(g VSS∙h) with 4 and 5% LPD addition. With the addition of 7.5% LPD, SAA dropped to a value of 18.1 mg N/(g VSS∙h) in the LPD reactor.

  • Application of the Chimney Cap as a Method of Improving the Effectiveness of Natural Ventilation in Buildings
    • Romana Antczak-Jarząbska
    • Maciej Niedostatkiewicz
    2020 Full text Polish Maritime Research

    Adequately designed natural ventilation is the cheapest and easiest way to effectively remove indoor pollutants and keep the air inside a building fresh. A prediction of the performance and effectiveness of ventilation in order to determine the design of a ventilation system can provide real and long-term cost savings. The worst time in terms of the efficiency of natural ventilation is the spring-autumn transition period [7]. In order to improve the efficiency of natural ventilation, chimney caps are used, among others. They are designed to improve the chimney effect described in colloquial language as a chimney draft. The chimney effect is a physical phenomenon of the formation of a spontaneous flow of a warmer gas, e.g. air, from the bottom up in stem channels [12]. The article analyses the influence of the chimney cowl on the improvement of the chimney effect in an apartment of a multi-family building with natural ventilation. Long-term tests of the chimney draft were carried out for the case without and with a chimney cap. The paper presents the results of the performance (air change rate, ACH) of natural ventilation for a building with an inlet gap measured for the transitional season (between the heating and the summer season). The measurements were performed during a windy period.

  • APPLICATION OF THE GWR MODEL FOR PREDICTING THE ROAD FATALITIES RATE ON THE ROAD NETWORK IN THE NUTS 3 REGIONS IN EUROPE ON THE EXAMPLE OF KUYAVIAN- -POMERANIAN VOIVODESHIP
    • Joanna Wachnicka
    • Katarzyna Palikowska
    2020 Full text Journal of KONBiN

    The article presents the application of the GWR (Geographically Weighted Regression) model to the description of differences in the level of road traffic safety in individual counties on the example of the Kuyavian-Pomeranian Voivodeship. The GWR model developed for counties, taking into account the diversity of NUTS 3 regions, can be a helpful tool for traffic safety management in voivodships and lower administrative units, and such an approach has not yet been applied.

  • Application of the LifeRoSE method in funcionality evaluation of road safety equipment
    • Anna Gobis
    • Kazimierz Jamroz
    • Łukasz Jeliński
    2020 Full text Journal of KONBiN

    The article presents a mathematical model of the life cycle estimation method of road safety equipment. Then the model was adjusted to estimate the life cycle costs of the chosen horizontal road marking. Using the LCC method, the functionality of the horizontal marking was evaluated in terms of efficiency, durability and economic effectiveness. The article also presents the impact of selected factors on the life cycle costs of the horizontal road marking

  • Application of the Monte Carlo algorithm for solving volume integral equation in light scattering simulations
    • Maciej Kraszewski
    • Jerzy Pluciński
    2020 Full text OPTICA APPLICATA

    Various numerical methods were proposed for analysis of the light scattering phenomenon. Important group of these methods is based on solving the volume integral equation describing the light scattering process. The popular method from this group is the discrete dipole approximation (DDA). DDA uses various numerical algorithms to solve the discretized integral equation. In the recent years, the application of the Monte Carlo (MC) algorithm as one of them was proposed. In this research, we analyze application of the MC algorithm for two cases: the light scattering by large particles and by random conglomerates of small particles. We show that if proper preconditioning of the numerical problem is applied, the MC algorithm can solve the underlying systems of linear equations. We also show that the efficiency of the MC algorithm can be increased by reusing performed computations for various incident electromagnetic waves and the applicability of the MC algorithm depends on the particular use case. It is unlikely to be used in the case of light scattering by the large particles due to computational times inferior comparing with the other numerical methods but may become useful in the case of light scattering by the random conglomerates of small scattering particles.

  • Application of the neural networks for developing new parametrization of the Tersoff potential for carbon
    • Anthony Chukwuemeka Nwachukwu
    • Szymon Winczewski
    2020 Full text TASK Quarterly

    Penta-graphene (PG) is a 2D carbon allotrope composed of a layer of pentagons having sp2- and sp3-bonded carbon atoms. A study carried out in 2018 has shown that the parameterization of the Tersoff potential proposed in 2005 by Ehrhart and Able (T05 potential) performs better than other potentials available for carbon, being able to reproduce structural and mechanical properties of the PG. In this work, we tried to improve the T05 potential by searching for its parameters giving a better reproduction of the structural and mechanical properties of the PG known from the ab initio calculations. We did this using Molecular Statics (MS) simulations and Neural Network (NN). Our test set consisted of the following structural properties: the lattice parameter a; the interlayer spacing h; two lengths of C-C bonds, d1 and d2 respectively; two valence angles, 1 and 2, respectively. We also examined the mechanical properties by calculating three elastic constants, C11, C12 and C66, and two elastic moduli, the Young’s modulus and the Poisson’s ratio . We used MS technique to compute the structural and mechanical properties of PG at = 0 K. The Neural Network used is composed of 2 hidden layers, with 20 and 10 nodes for the first and second layer, respectively. We used an Adams optimizer for the NN optimization and the Mean Squared Error as the loss function. We obtained inputs (about 80 000 different sets of potential parameters) for the Molecular Statics simulation by using randomly generated numbers. The outputs from these simulations became the inputs to our Neural Network. The Molecular Statics simulations were done with LAMMPS while the Neural Network and other computations were done with Python, Pytorch, Numpy, Pandas, GNUPLOT and Bash scripts. We obtained a parameterization which has a slightly better accuracy (lower relative errors of the calculated structural and mechanical properties) than the original parameterization.

  • Applying artificial neural networks for modelling ship speed and fuel consumption
    • Wiesław Tarełko
    • Krzysztof Rudzki
    2020 Full text NEURAL COMPUTING & APPLICATIONS

    This paper deals with modelling ship speed and fuel consumption using artificial neural network (ANN) techniques. These tools allowed us to develop ANN models that can be used for predicting both the fuel consumption and the travel time to the destination for commanded outputs (the ship driveline shaft speed and the propeller pitch) selected by the ship operator. In these cases, due to variable environmental conditions, making decisions regarding setting the proper commanded outputs to is extraordinarily difficult. To support such decisions, we have developed a decision support system. Its main elements are the ANN models enabling ship fuel consumption and speed prediction. To collect data needed for building ANN models, sea trials were conducted. In this paper, the decision support system concept, input and variables of the ship driveline system models, and data acquisition methods are presented. Based on them, we developed appropriate ANN models. Subsequently, we performed a quality assessment of the collected data set, data normalization and division of the data set, selection of an ANN model architecture and assessment of their quality.

  • Applying case studies to teaching architectural investment
    • Michał Kwasek
    • Rafał Janowicz
    2020 Full text World Transactions on Engineering and Technology Education

    Case studies enable students to encounter practical issues during their education. Experiments conducted in class employing this method often feature simplified models of real-world situations. However, they still enable students to encounter actual problems, to which theoretical knowledge is applied. In architectural education, students carrying out semester projects usually rely on data provided by the teacher, without wondering where the data came from. The case study method described here was implemented by means of a graph and in accordance with the principles of turquoise teaching. It has been implemented and used for several years in classes, where architecture students are taught how to manage their company and how to organise the investment process. The teaching covers essential guidelines that determine how the architect-manager works. Discussed in this article are the advantages of the method, the impact of it on the effectiveness of education and its application.

  • Approximation of Fractional Order Dynamic Systems Using Elman, GRU and LSTM Neural Networks
    • Bartosz Puchalski
    • Tomasz Rutkowski
    2020 Full text

    In the paper, authors explore the possibility of using the recurrent neural networks (RNN) - Elman, GRU and LSTM - for an approximation of the solution of the fractional-orders differential equations. The RNN network parameters are estimated via optimisation with the second order L-BFGS algorithm. It is done based on data from four systems: simple first and second fractional order LTI systems, a system of fractional-order point kinetics and heat exchange in the nuclear reactor core and complex nonlinear system. The obtained result shows that the studied RNNs are very promising as approximators of the fractional-order systems. On the other hand, these approximations may be easily implemented in real digital control platforms.

  • Aptamer based tools for environmental and therapeutic monitoring: A review of developments, applications, future perspectives
    • Błażej Kudłak
    • Monika Wieczerzak
    2020 Full text CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY

    Nucleic acids in the form of aptamers play a growing and significant role in the targeted and rapid analysis of environmental sample composition and medical analyses. In this paper, the review of both aptamers synthesis methods as well as application of these short chain oligonucleotides (with critical comments on their strong and weak features) are given. The first ones include: systematic evolution of ligands by exponential enrichment (SELEX), high throughput aptamer identification screen (HAPIscreen), and a non-equilibrium capillary electrophoresis of equilibrium mixture (NECEEM). Afterwards, manuscript describes variety of sensors and biotests utilizing aptamers as active part of its action starting from electrochemical aptasensors, through optical to piezo-electric ones. Described biotests present basic developments in enzymelinked apta-sorbent assays (ELASA) that can be performed with different variations (enzyme-linked aptamer assay (ELAA), enzyme-linked oligonucleotide assay (ELONA) and aptamerlinked immobilized sorbent assay (ALISA)). Next, the review presents advantages and drawbacks of recent aptameric developments in versatile laboratory applications, namely medical ones, as well as analytical and bioassays. Utilitarian development of aptasensors and aptamers would strongly benefit from an assembly of interdisciplinary teams containing chemists, physicists, biologists, medical doctors, and material and electronic scientists, to determine the most effective application methodologies.

  • Architektura pomników poświęconych ofiarom ataków terrorystycznych jako kontynuacja realizacji komemoratywnych kształtowanych w postpamięci
    • Agnieszka Gębczyńska-Janowicz
    • Anna Awtuch
    2020 Full text Politeja. Pismo Wydziału Studiów Międzynarodowych i Politycznych Uniwersytetu Jagiellońskiego

    architecture of Memorials Dedicated to the Victims of terrorist attacks as a continuation of commemorative Structures created within Post-memory Having the rich art of commemorating events of the Second World War as a key reference, this article will try to show how contemporary architectural interven- tions in public space make attempts to respond to the social need of dealing with traumatic events and formulating a new attitude towards threatened places. The point of reference for our reflections will be the events affecting contemporary city in the 21th century associated with terrorist attacks. In order to determine types of architectural narratives about traumatic events developed in urban space, some memorial places in Europe and the USA will be analysed (e.g. Atocha station in Madrid, 9/11 Memorial in New York, Oklahoma City Bombing Memorial). Referring to examples of memorials and monuments, we will look at contempo- rary tendencies in designing commemorative architecture and how architecture reflects and supports the social and individual process of trauma recovery.

  • Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric
    • Paweł Kłosowski
    • Krzysztof Żerdzicki
    • Krzysztof Woźnica
    2020 Full text Jove-Journal of Visualized Experiments

    Architectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed method is based on the accelerated ageing approach proposed by Arrhenius. 300 mm x 50 mm samples were cut in the warp and fill directions and placed in a thermal chamber at 80 °C for up to 12 weeks or at 90 °C for up to 6 weeks. Then after one week of conditioning at ambient temperature, the samples were uniaxially tensioned at a constant strain rate. Experimentally, the parameters were determined for the non-linear elastic (linear piecewise) and viscoplastic (Bodner–Partom) models. Changes in these parameters were studied with respect to the ageing temperature and ageing period. In both cases, the linear approximation function was successfully applied using the simplified methodology of Arrhenius. A correlation was obtained for the fill direction between experimental results and the results from the Arrhenius approach. For the warp direction, the extrapolation results exhibited some differences. Increasing and decreasing tendencies have been observed at both temperatures. The Arrhenius law was confirmed by the experimental results only for the fill direction. The proposed method makes it possible to predict real fabric behavior during long term exploitation, which is a critical issue in the design process

  • Assessing Industry 4.0 Features Using SWOT Analysis
    • Ahmad Reshad Bakhtari
    • Mohammad Waris
    • Bisma Mannan
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Full text Communications in Computer and Information Science

    This paper assesses some features of industry 4.0 by using SWOT analysis that affects the adoption and implementation of industry 4.0. The paper identifies the strengths, weaknesses, opportunities, and threats related to industry 4.0. By the consideration of these four groups of factors, the industrial practitioners can understand how to implement industry 4.0. Moreover, industrial practitioners can use the strengths/opportunities offered by industry 4.0 to take strategic decisions to decrease the effect of the threats/weaknesses that come along with industry 4.0.

  • Assessment of Citizens’ Actions against Light Pollution with Guidelines for Future Initiatives
    • Karolina Zielińska-Dąbkowska
    • Kyra Xavia
    • Katarzyna Bobkowska
    2020 Full text Sustainability

    Due to the wide reach of media reports about scientific research and technological tools such as the world wide web (WWW), the Internet, and web browsers, citizens today have access to factual information about the negative impact of artificial light at night (ALAN) on their dark skies, and their health and well-being. This means they can now make educated decisions and take the necessary steps to help protect themselves and their communities from disruptive light pollution. Whilst this action is positive and welcomed, unfortunately, according to collected data, not all such initiatives have been successful. Although our understanding of this groundswell movement is deepening, further studies are required to complete a worldwide picture of the current situation. This paper therefore investigates the various actions taken by citizens, as well as the challenges, methods, and tools involved, regarding good practices initiated by grass roots activism on how to reduce existing and potential light pollution. The results of a comparative analysis of 262 international case studies (lawsuits and online petitions) reveal that, since the 1990s, there has been an increase in the number of legal cases related to light pollution due to the rise in public awareness, the availability of scientific knowledge via the Internet, and the ability to take accurate lighting measurements and perform lighting simulations. Also, in the last decade a new tool for digital participation in the form of online petitions has established a new movement of citizen action to mitigate the effects of light pollution. Based on this information, a seven-step framework involving recommendations for citizen action has been developed. It is expected that this new knowledge will benefit those citizens planning future efforts involving the development, implementation, and monitoring processes of outdoor lighting. Additionally, it might support the evolution of planning and policy approaches that are sustainable and necessary to improve the application and installation of ecologically/biologically responsible illumination for towns, cities, and natural habitats.

  • Assessment of Electronic Sensing Techniques for the Rapid Identification of Alveolar Echinococcosis through Exhaled Breath Analysis
    • Andrzej Kwiatkowski
    • Tomasz Chludziński
    • Tarik Saidi
    • Tesfalem Welearegay
    • Aylen Jaimes-Mogollón
    • Nezha El Bari
    • Sebastian Borys
    • Benachir Bouchikhi
    • Janusz Smulko
    • Radu Ionescu
    2020 Full text SENSORS

    Here we present a proof-of-concept study showing the potential of a chemical gas sensors system to identify the patients with alveolar echinococcosis disease through exhaled breath analysis. The sensors system employed comprised an array of three commercial gas sensors and a custom gas sensor based on WO3 nanowires doped with gold nanoparticles, optimized for the measurement of common breath volatile organic compounds. The measurement setup was designed for the concomitant measurement of both sensors DC resistance and AC fluctuations during breath samples exposure. Discriminant Function Analysis classification models were built with features extracted from sensors responses, and the discrimination of alveolar echinococcosis was estimated through bootstrap validation. The commercial sensor that detects gases such as alkane derivatives and ethanol, associated with lipid peroxidation and intestinal gut flora, provided the best classification (63.4% success rate, 66.3% sensitivity and 54.6% specificity) when sensors’ responses were individually analyzed, while the model built with the AC features extracted from the responses of the cross-reactive sensors array yielded 90.2% classification success rate, 93.6% sensitivity and 79.4% specificity. This result paves the way for the development of a noninvasive, easy to use, fast and inexpensive diagnostic test for alveolar echinococcosis diagnosis at an early stage, when curative treatment can be applied to the patients

  • ASSESSMENT OF FINANCIAL SECURITY OF AN ENTERPRISE ON THE BASIS OF BEHAVIORAL ECONOMICS
    • Oleksandr Melnychenko
    2020 Full text BULLETIN OF THE CHERKASY BOHDAN KHMELNYTSKY NATIONAL UNIVERSITY. ECONOMIC SCIENCES

    The article substantiates that the level of company’s financial security depends not so much on the indicators of its activity, but on its perception of decision-makers and other stakeholders. At the same time, this perception is formed due to the continuous participation of the stakeholder in operations, constant monitoring of financial indicators, the study of current approaches to enterprise management, changes in the environment, market conditions, etc. The role of economic analysis in assessing company’s financial security as a state is not in its complex study, but in the presented economic indicators, the processing of quantitative data on the company’s financial security. Instead, to speak of a comprehensive and thorough study of the level of financial security on the basis of economic analysis only would be incorrect and unreliable. Indices, indicators that are analyzed on the basis of financial or management reporting provide only a cursory view of the problem or even distort the overall picture, as they are taken at a particular point in time. For example, liquidity indicators change in certain groups of businesses and the country's economic or political environment can transform a liquid company with a solid stock of liquidity into absolutely illiquid in a few moments. However, considering the previous data of economic analysis without bearing in mind other aspects, it is possible to make fatal decisions for the company. Although, of course, such a scenario is impossible, since behind each enterprise there are people, whose decisions and experience depend on its further development, and practice shows that such people are not oriented solely to economic analysis data without context, to assess the situation in the economy of the country or the world in general. Their experience and perception of financial security are essencial in decision making. Thus, the paper argues that the method of expert assessment of company’s financial security is the most objective one, which, however, has disadvantages associated with cognitive limitations of people

  • Assessment of the Effective Variants Leading to Higher Efficiency for the Geothermal Doublet, Using Numerical Analysis‒Case Study from Poland (Szczecin Trough)
    • Anna Wachowicz-Pyzik
    • Anna Sowiżdżał
    • Leszek Pająk
    • Paweł Ziółkowski
    • Janusz Badur
    2020 Full text ENERGIES

    Numerical models of geothermal doublet allows us to reduce the high risk associated with the selection of the most eective location of a production well. Furthermore, modeling is a suitable tool to verify possible changes in operational geothermal parameters, which guarantees liveliness of the system. An appropriate selection of software as well as the methodology used to generate numerical models significantly aects the quality of the obtained results. In this paper, the authors discuss the influence of such parameters as grid density and distance between wells on the eciency of geothermal heating plant. The last stage of the analysis was connected with estimation of geothermal power potential for a hypothetical geothermal doublet. Numerical simulations were carried out using the TOUGH2 code, which applies the finite-dierence method. The research was conducted in the Szczecin Trough area (NW Poland), based on archival data from Choszczno IG-1 well. The results demonstrated that in the studied case of the Choszczno region, the changes in the distance of boreholes can have a visible influence on obtained results; however the grid density of the numerical model did not achieve a significant impact on it. The results show the significant importance of numerical modeling aimed at increasing the eciency of a potential geothermal heating plant.

  • Assessment of the Speed Management Impact on Road Traffic Safety on the Sections of Motorways and Expressways Using Simulation Methods
    • Jacek Oskarbski
    • Tomasz Kamiński
    • Kyandoghere Kyamakya,
    • Jean Chamberlain Chedjou,
    • Karol Żarski
    • Małgorzata Pędzierska
    2020 Full text SENSORS

    Methods used to evaluate the impact of Intelligent Transport System (ITS) services on road safety are usually based on expert assessments or statistical studies. However, commonly used methods are challenging to apply in the planning process of ITS services. This paper presents the methodology of research using surrogate safety measures calculated and calibrated with the use of simulation techniques and a driving simulator. This approach supports the choice of the type of ITS services that are beneficial for traffic efficiency and road safety. This paper presents results of research on the influence of selected scenarios of variable speed limits on the eciency and safety of traffic on the sections of motorways and expressways in various traffic conditions. The driving simulator was used to estimate the eciency of lane-keeping by the driver. The simulation traffic models were calibrated using driving simulator data and roadside sensor data. The traffic models made it possible to determine surrogate safety measures (number of conflicts and their severity) in selected scenarios of using ITS services. The presented studies confirmed the positive impact of Variable Speed Limits (VSLs) on the level of road safety and traffic efficiency. This paper also presents recommendations and plans for further research in this area.

  • Assessment of Trajectories of Non-bankrupt and Bankrupt Enterprises
    • Tomasz Korol
    2020 Full text European Research Studies Journal

    The aim of this study is to show how long-term trajectories of enterprises can be used to increase the forecasting horizon of bankruptcy prediction models. The author used seven popular forecasting models (two from Europe, two from Asia, two from North America and one from Latin America). These models (five multivariate discriminant analysis models and two logit models) were used to develop 17-year trajectories separately for non-bankrupt enterprises and those at risk of financial failure. Based on a sample of 200 enterprises, the author evaluated the differences between non-bankrupt and bankrupt firms in development during 17 years of activity. The long-term usability of the models was demonstrated. To date, these models have been used only to forecast bankruptcy risk in the short term (1–3 years’ prediction horizon). This paper demonstrates that these models can also serve to evaluate long-term growth and to identify the first symptoms of future bankruptcy risk many years before it actually occurs. It was proven and specified that long-term developmental differences exist between non-threatened and future insolvent companies. These studies proved that the process of going bankrupt is very long, perhaps even longer than the literature has previously demonstrated. This study is one of the first attempts in the literature globally to assess such long-term enterprise trajectories. Additionally by implementing a dynamic approach to the financial ratios in the risk-forecasting model let visualize the changes occurring in the company.

  • Assessment of Wide-Sense Stationarity of an Underwater Acoustic Channel Based on a Pseudo-Random Binary Sequence Probe Signal
    • Iwona Kochańska
    2020 Full text Applied Sciences-Basel

    The performances of Underwater Acoustic Communication (UAC) systems are strongly related to the specific propagation conditions of the underwater channel. Designing the physical layer of a reliable data transmission system requires a knowledge of channel characteristics in terms of the specific parameters of the stochastic model. The Wide-Sense Stationary Uncorrelated Scattering (WSSUS) assumption simplifies the stochastic description of the channel, and thus the estimation of its transmission parameters. However, shallow underwater channels may not meet the WSSUS assumption. This paper proposes a method for testing the Wide-Sense Stationary (WSS) part of the WSSUS feature of a UAC channel on the basis of the complex envelope of a received probe Pseudo-Random Binary Sequence (PRBS) signal. Two correlation coefficients are calculated that can be interpreted, together, as a measure that determines whether the channel is WSS or not. A similar wide-sense stationarity assessment can be performed on the basis of the Time-Varying Impulse Response (TVIR) of a UAC channel. However, the method proposed in this paper requires fewer computational operations in the receiver of a UAC system. PRBS signal transmission tests were conducted in the UAC channel simulator and in real conditions during an inland water experiment. The correlation coefficient values obtained using the method based on the envelope of a probe signal and the method of analysing the TVIR estimates are compared. The results are similar, and thus, it is possible to assess if the UAC channel can be modelled as a WSS stochastic process without the need for TVIR estimation.