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Gdańsk University of Technology

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Publications from the year 2020

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  • Quality of Service in ASON/GMPLS Network with Hierarchical Control Plane Structure
    • Sylwester Kaczmarek
    • Magdalena Młynarczuk
    2020

    The paper presents the problem of quality of service for hierarchical control plane structure of Automatically Switched Optical Network (ASON) utilizing Generalized Multi-Protocol Label Switching (GMPLS). The approach is implemented to control the multidomain network with required quality of service, in a use case of incomplete domain network information. The authors examine different factors, including resource reservation algorithms with pools resources assumptions to indicate if they have significant impact on required quality of service in ASON/GMPLS network with hierarchical control plane. The analysis is performed by simulating the European network structure with the use of OMNeT++ discrete-event simulator.

  • QUANTITATIVE EASING POLICY AND ITS IMPACT ON THE GLOBAL ECONOMY
    • I. Shkodina
    • Oleksandr Melnychenko
    • M. Babenko
    2020 Full text Financial and Credit Activity-Problems of Theory and Practice

    Based on the analysis of the impact of quantitative easing policies on the global economy, there was concluded that the world’s largest central banks and widespread debt stimulation have created the model of economic growth. This model was based on the productivity growth. The lack of productivity growth in the developed world, the active integration of developing countries (first of all China and India) in the global economy have completely changed the directions of global financial flows and caused fundamental geopolitical changes. Striving to confront the cyclical nature of the economy, government regulators transform the global economy into a «zombie economy». There are unprofitable companies and banks, which operate on cheap money from central banks and government bailouts. The monetization of fiscal policy transforms the risks from governments to central banks and destroys their independence. We concluded that the strategy of tackling the global economy through cheap credit is doomed to failure because governments do not solve the problems of real economy, productivity increase, management of public and corporate debt, stagflation, unemployment, and increase in income differentiation. Nowadays, in the context of COVID-19 pandemic, central banks use the new and forgotten old tools to expand economic activity (so-called QE and «Not QE»). These tools provide the necessary stimulus only in the short-term period, but in the long term period it will inevitably lead to serious disparities, undermine the market mechanism, increase the administrative influence and lead the global economy to a choice between depression, unemployment, hyperinflation or systemic collapse. We believe that the global coronavirus pandemic stimulates the scientific debate on rethinking monetary policy goals and instruments, as the use of various «non-standard tools» has repeatedly proven ineffective in combating crises and it has helped only to create new global imbalances and crises.

  • Quantitative Storytelling in the Making of a Composite Indicator
    • Marta Kuc-Czarnecka
    • Samuele Piano, Lo
    • Andrea Saltelli,
    2020 Full text Social Indicators Research

    The reasons for and against composite indicators are briefly reviewed, as well as the available theories for their construction. After noting the strong normative dimension of these measures—which ultimately aim to ‘tell a story’, e.g. to promote the social discovery of a particular phenomenon, we inquire whether a less partisan use of a composite indicator can be proposed by allowing more latitude in the framing of its construction. We thus explore whether a composite indicator can be built to tell ‘more than one story’ and test this in practical contexts. These include measures used in convergence analysis in the field of cohesion policies and a recent case involving the World Bank’s Doing Business Index. Our experiments are built to imagine different constituencies and stakeholders who agree on the use of evidence and of statistical information while differing on the interpretation of what is relevant and vital.

  • Quasi-Global Optimization of Antenna Structures Using Principal Components and Affine Subspace-Spanned Surrogates
    • Jon Tomasson
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2020 Full text IEEE Access

    Parametric optimization is a mandatory step in the design of contemporary antenna structures. Conceptual development can only provide rough initial designs that have to be further tuned, often extensively. Given the topological complexity of modern antennas, the design closure necessarily involves full-wave electromagnetic (EM) simulations and—in many cases—global search procedures. Both factors make antenna optimization a computationally expensive endeavor: population-based metaheuristics, routinely used in this context, entail significant computational overhead. This letter proposes a novel approach that interleaves trust-region gradient search with iterative parameter space exploration by means of local kriging surrogate models. Dictated by efficiency, the latter are rendered in low-dimensional subspaces spanned by the principal components of the antenna response Jacobian matrix, extracted to identify the directions of the maximum (frequency-averaged) response variability. The aforementioned combination of techniques enables quasi-global search at the cost comparable to local optimization. These features are demonstrated using two antenna examples as well as benchmarking against multiple-start local tuning.

  • Radar and Sonar Imaging and Processing
    • Andrzej Stateczny
    • Witold Kazimierski
    • Krzysztof Kulpa
    2020 Full text Remote Sensing

    The 21 papers (from 61 submitted) published in the Special Issue “Radar and Sonar Imaging Processing” highlighted a variety of topics related to remote sensing with radar and sonar sensors. The sequence of articles included in the SI dealt with a broad profile of aspects of the use of radar and sonar images in line with the latest scientific trends. The latest developments in science, including artificial intelligence, were used.

  • Random field model of foundations at the example of continuous footing
    • Kamil Żyliński
    • Aleksandra Korzec
    • Karol Winkelmann
    • Jarosław Górski
    2020 Full text AIP Conference Proceedings

    The purpose of the paper is to indicate an efficient method of foundation settlement analysis taking into account the variability of soil properties. The impact of the random variable distribution (Gauss or Lognormal) describing soil stiffness on foundation deposits was assessed. The Monte Carlo simulation method was applied in the computations. The settlements of the strip foundation with the subsoil described by a single random variable and a random field were compared.

  • Random field modelling of mechanical behaviour of corroded thin steel plate specimens
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2020 Full text ENGINEERING STRUCTURES

    The objective of this work is to explore the possibility of corrosion degradation modelling of thin steel plate specimens with the use of random field approach. The mechanical properties are obtained via the nonlinear Finite Element Analysis with the use of an explicit dynamic solver. The fully nonlinear material model is adopted to obtain the proper stress-strain response. Sensitivity analysis considering the main statistical descriptors of the random field is performed. The results of the analysis are validated with the available experimental data showing a good agreement for lower levels of Degree of Degradation and significant deviations for severely corroded specimens. The analysis shows that the irregularities in the corroded plate surface are one of the main reason for the mechanical properties reduction. Random field modelling revealed to be a swift and practical tool for representing the corroded surfaces in steel structures.

  • Ranking of Generation Source Locations by a Hybrid Multi-Criteria Method
    • Alicja Stoltmann
    • Marcin Jaskólski
    • Paweł Bućko
    2020 Full text Acta Energetica

    The paper presents a ranking of the locations of eight renewable energy sources (RES) made using a hybrid multi-criteria analysis method. The method is a combination of the analytical hierarchical process (AHP) method and numerical taxonomy. The considered generating sources, i.e. solar plants, biogas plants, and wind farms are sources that will significantly contribute to implementing the provisions of the energy and climate package for Poland (by 2030). Increasing the share of energy from renewable sources will increase the country's energy security. Low-emission generation sources obtain energy from renewable sources. Therefore, their location is influenced by factors such as environmental impact, availability and origin of raw materials, e.g. biogas, as well as technological aspects. The multitude of factors mentioned makes the location of a biogas plant a multi-threaded issue. The AHP method is a mathematical method with a high degree of sophistication and time consumption. The method's advantage is its ability to compare countable and uncountable factors with each other, which was used in conjunction with the numerical taxonomy method. The analysis' effect is ranking of the locations in question.

  • Ranking Speech Features for Their Usage in Singing Emotion Classification
    • Szymon Zaporowski
    • Bożena Kostek
    2020 Full text

    This paper aims to retrieve speech descriptors that may be useful for the classification of emotions in singing. For this purpose, Mel Frequency Cepstral Coefficients (MFCC) and selected Low-Level MPEG 7 descriptors were calculated based on the RAVDESS dataset. The database contains recordings of emotional speech and singing of professional actors presenting six different emotions. Employing the algorithm of Feature Selection based on the Forest of Trees method, descriptors with the best ranking results were determined. Then, the emotions were classified using the Support Vector Machine (SVM). The training was performed several times, and the results were averaged. It was found that descriptors used for emotion detection in speech are not as useful for singing. Also, an approach using Convolutional Neural Network (CNN) employing spectrogram representation of audio signals was tested. Several parameters for singing were determined, which, according to the obtained results, allow for a significant reduction in the dimensionality of feature vectors while increasing the classification efficiency of emotion detection.

  • Rapid and simple multi-analyte LC–MS/MS method for the determination of benzodiazepines and Z-hypnotic drugs in blood samples: Development, validation and application based on three years of toxicological analyses
    • Laura Banaszkiewicz
    • Mateusz Woźniak
    • Marzena Kata
    • Ewa Domagalska
    • Marek Wiergowski
    • Beata Szpiech
    • Agata Kot-Wasik
    2020 JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS

    Benzodiazepines (BZDs) and Z-drugs have been particularly important treatments for sleeping and anxiety disorders for many years. However, recently, a number of new benzodiazepines (named designer benzodiazepines, DBZDs) were synthesised, but some of them have never been used in the clinic; they reached the black drug market as new psychoactive substances and are used for recreational purposes. The abuse of these substances has led to many crimes and even deaths. Therefore, it is necessary to develop new methods for their quantification for forensic and clinical toxicology. A liquid chromatography–tandem mass spectrometry-based method was developed for the simultaneous determination of 20 classical BZDS, 4 DBZDs and 3 Z-hypnotic drugs in human whole blood. As a sample preparation step, liquid-liquid extraction requiring the use of only 0.5 mL of blood sample and 1 mL of extraction solvent was applied. The selectivity, linearity, carry-over effects, limits of detection (LOD) and quantification (LOQ), precision, accuracy (both intra- and inter-day assays) and recovery were evaluated for validation. Calibration curves were linear with r values > 0.98. The LODs ranged from 0.01 to 0.33, and the LOQs were assumed to be 1 ng/mL. Inter-day precisions and accuracies were in the ranges of 87.8% - 108.5% and 1.8% - 11.2%, respectively. The recovery values ranged from 81.0% to 106.7%. The developed method proved to be sensitive, specific, simple, and fast and can be quickly modified and expanded for new compounds by the optimization of MRM. The method was applied for analysis of blood samples in 145 toxicological cases over a three-year study (2017 - 2019), which allowed us to obtain information on the prevalence of the use of these substances. The most frequently determined compounds were nordazepam (87 cases; 60%), diazepam (81 cases; 55.9%), temazepam (72 cases; 49.7%), oxazepam (56 cases; 38.7%), and midazolam (36 cases; 24.8%). The ranges of concentrations were wide and are presented as box plots. The results were used for the preparation of medico-legal opinions, which proved the utility of the method for routine toxicology analyses.

  • Rapid multi-objective optimization of antennas using nested kriging surrogates and single-fidelity EM simulation models
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2020 Full text ENGINEERING COMPUTATIONS

    Ever increasing performance requirements make the design of contemporary antenna systems a complex and multi-stage process. One of the challenges, pertinent to the emerging application areas but also some of the recent trends (miniaturization, demands for multi-functionality, etc.), is the necessity of handling several performance figures such as impedance matching, gain, or axial ratio, often over multiple frequency bands. The fundamental difficulty is that most of the design objectives are at least partially conflicting. Hence, an improvement of one generally implies degradation of the others. The knowledge of available trade-offs is indispensable and can be acquired through multi-objective optimization (MO). Unfortunately, MO is computationally expensive when executed at the level of EM simulation models, otherwise necessary from the standpoint of antenna evaluation reliability. This paper proposes a computationally efficient framework for MO of antennas. Its keystone is the recently introduced nested kriging modeling technology, here adopted for identifying the design space region that contains the best design trade-offs, as well as for constructing a fast surrogate model to be processed by the MO algorithm. The technique is demonstrated through a two-objective optimization of a planar Yagi antenna (with respect to the impedance matching and gain enhancement) and three-objective design of a compact wideband antenna (with respect to the impedance matching, gain variability, and the footprint area). In both cases, the Pareto set is obtained at the low cost of a few hundred of antenna simulations, even though the optimization process is exclusively based on high-fidelity EM analysis.

  • Rapid optimization of compact microwave passives using kriging surrogates and iterative correction
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2020 Full text IEEE Access

    Design of contemporary microwave components is—in a large part—based on full-wave electromagnetic (EM) simulation tools. The primary reasons for this include reliability and versatility of EM analysis. In fact, for many microwave structures, notably compact components, EM-driven parameter tuning is virtually imperative because traditional models (analytical or network equivalents) are unable to account for the cross-coupling effects, strongly present in miniaturized layouts. At the same time, the cost of simulation-based design procedures may be significant due to a typically large number of evaluations of the circuit at hand involved. In this paper, a novel approach to expedited design closure of compact microwave passives is presented. The proposed procedure incorporates available designs (e.g., existing from the previous design work on the same structure) in the form of the kriging interpolation models, utilized to yield a reasonable initial design and to accelerate its further refinement. An important component of the framework is an iterative correction procedure that feeds the accumulated discrepancies between the target and the actual design objective values back to the kriging surrogate to produce improved predictions. The efficacy of our methodology is demonstrated using two miniaturized impedance matching transformers with the optimized designs obtained at the cost of a few EM simulations of the respective circuits. The relevance of the iterative correction is corroborated through the comparative studies showing its superiority over rudimentary gradient-based refinement.

  • Rapid redesign of multiband antennas with respect to operating conditions and material parameters of substrate
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    2020 Full text INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS

    This work addresses geometry parameter scaling of multi-band antennas for Internet of Things applications. The presented approach is comprehensive and permits re-design of the structure with respect to both the operating frequencies and material parameters of the dielectric substrate. A two-step procedure is developed with the initial design obtained from an inverse surrogate model constructed using a set of appropriately prepared reference points, and the final design identified through an iterative correction procedure. The latter is necessary in order to account for limited accuracy of the surrogate. The proposed approach is validated using a dual-band microstrip patch antenna scaled over wide ranges of operating frequencies (1.5 GHz to 2.5 GHz for the lower band, and 5.0 GHz to 6.0 GHz for the upper band), substrate thickness (0.7 mm to 1.5 mm), and substrate permittivity (2.5 to 3.5). The re-design cost corresponds to only up to three electromagnetic simulations of the antenna at hand. Reliability of the process is confirmed through experimental validation of the fabricated antenna prototypes.

  • Rapid tolerance‐aware design of miniaturized microwave passives by means of confined‐domain surrogates
    • Anna Pietrenko-Dąbrowska
    2020 INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS

    The effects of uncertainties, primarily manufacturing tolerances but also incomplete information about operating conditions or material parameters, can be detrimental to the performance of microwave components. Quantification of such effects is essential to ensure a meaningful evaluation of the structure, in particular, its reliability under imperfect fabrication procedures. The improvement of the circuit robustness can be achieved by reducing sensitivity to geometry/material parameter deviations, which requires optimization of suitably chosen statistical performance metrics such as the yield. The prerequisite for the latter is statistical analysis. In the case of compact circuits, it is executed through full‐wave electromagnetic (EM) analysis. The fundamental difficulty, that is, the high CPU cost, can be alleviated by the employment of fast surrogate models, which is the method of choice for the majority of contemporary approaches. Despite its advantages, a practical challenge of surrogate‐assisted design is the initial computational overhead related to metamodel construction. As a workaround, this work proposes the employment of a recently introduced concept of constrained modelling, where the surrogate domain is confined only to contain the essential subsets of the parameter space. In the context of yield optimization, the domain needs to correspond to directions featuring maximum variability of the circuit responses (particularly the parts thereof that affect the yield value in the most significant way) with respect to its geometry parameters. The small volume of the domain spanned by such directions permits setting up an accurate model using a fraction of training data samples required by conventional methods. The proposed technique is demonstrated using a miniaturized microstrip rat‐race coupler with its yield optimized at the cost of just a few dozen of EM simulations of the circuit. EM‐based Monte Carlo simulations corroborate the reliability of the approach.

  • Raportowanie obrotu produktami leczniczymi w doskonaleniu przepływu informacji o stanach magazynowych aptek
    • Olga Mąka
    • Anna Zielińska
    • Grzegorz Zieliński
    2020 Problemy Jakości

    Celem opracowania jest identyfikacja roli raportowania obrotu produktami leczniczymi w aptekach. Zaprezentowano podstawowe założenia wymogu raportowania stanów magazynowych, w odniesieniu do poszczególnych grup interesariuszy, związanych z informacją o stanach magazynowych w aptece. Zidentyfikowano również korzyści dla poszczególnych grup interesariuszy wynikające z konieczności przygotowania tego typu raportów.

  • Raportowanie społeczne w sądach powszechnych
    • Sylwia Morawska
    • Przemysław Banasik
    2020

    Pomimo upływu 20 lat od pojawienia się pierwszych pionierskich badań nad raportowaniem społecznym w organizacjach publicznych stan wiedzy w tym obszarze jest wciąż na wczesnym etapie. Liczba obecnych badań, chociaż wykazuje tendencję wzrostową, jest nadal niewielka i są one lokalne. Niedobór prac teoretycznych z pewnością stanowi hamulec dla pełnego rozwoju potencjału tej dziedziny badań. Intencją autorów rozdziału jest opracowanie modelu raportowania społecznego w sądach powszechnych. Wykorzystano literaturę krajową i międzynarodową dotyczącą prezentowanej tematyki, a także dokonano analizy stron internetowych wszystkich sądów powszechnych w celu identyfikacji sposobów komunikowania działań prospołecznych na rzecz interesariuszy przez sąd. Badania wykazują, że sądy sporadycznie komunikują działania prospołeczne na rzecz swoich interesariuszy. Żaden z badanych sądów nie opublikował na stronie internetowej raportu społecznego.

  • Reactive extrusion of biodegradable aliphatic polyesters in the presence of free-radical-initiators: A review
    • Marta Przybysz-Romatowska
    • Józef Haponiuk
    • Krzysztof Formela
    2020 POLYMER DEGRADATION AND STABILITY

    Nowadays, growing attention is being paid to the environment and sustainability, what fully justified research works focused on modification of biodegradable polymers and their composites. In this field of research reactive extrusion seems to be the most promising approach, which fits well to sustainable development strategy. In In the present work, the in-situ modification of biodegradable aliphatic polyesters and the compatibilization of their blends by the action of free-radical initiators has been reviewed. The main concerns are the mechanisms of the free radicals induced modification of aliphatic polyesters and their blends. The cross-linked, branched or degraded structures of the formed polymers/blends were comprehensively characterized as function of modifier type and processing conditions. Moreover, the reactive processing and various types of irradiation in respect to the inter chain modification of polymers were presented. Main advantages and disadvantages related to reactive extrusion of biodegradable aliphatic polyesters and their blends in presence of free-radical-initiators were also pointed and discussed.

  • Reactive Processing and Functionalization of Ground Tire Rubber
    • Łukasz Zedler
    • Marta Przybysz-Romatowska
    • Aleksander Hejna
    • Xavier Colom
    • Javier Cañavate
    • Mohammad Saeb
    • Krzysztof Formela
    2020

    The dynamic development of the automotive industry resulted in a sig- nificant increase in rubber wastes, especially end-of-life tires, which are a serious threat to the natural environment and human health. This situation has enforced the industry and academic research groups to search new and cost-effective methods for recycling waste tires. In this field of research, reactive processing and functionaliza- tion seem to be a very promising approach to extend recycling and the ‘up-cycling’ of ground tire rubber. This chapter presents recent progress in the modification of waste rubber and valorization strategies with special attention on structure-properties relationships of the products obtained.

  • Reactive Sintering of Ground Tire Rubber (GTR) Modified by a Trans-Polyoctenamer Rubber and Curing Additives
    • Łukasz Zedler
    • Daria Kowalkowska-Zedler
    • Xavier Colom
    • Javier Cañavate
    • Mohammad Reza Saeb
    • Krzysztof Formela
    2020 Full text Polymers

    The proposed method of ground tire rubber (GTR) utilization involves the application of trans-polyoctenamer rubber (TOR), a commercially available waste rubber modifier. The idea was to investigate the influence of various curing additives (sulfur, N-cyclohexyl-2-benzothiazole sulfenamide (CBS), dibenzothiazole disulfide (MBTS) and di-(2-ethyl)hexylphosphorylpolysulfide (SDT)) on curing characteristics, physico-mechanical, thermal, acoustic properties as well as the morphology of modified GTR, in order to evaluate the possibility of reclaiming GTR and the co-cross-linking between applied components. The results showed that the presence of the modifier without the addition of curing additives hinders the physico-mechanical properties of revulcanized GTR. The addition of SDT, CBS, MBTS and sulfur change the melting kinetics of TOR, indicating partial degradation and/or co-cross-linking between components. In the studied conditions, the best mechanical properties were obtained by the samples cured with sulfur. The morphology analysis, combined with the physico-mechanical results, indicated that when the surface of the GTR is more developed, obtained by the addition of TOR, the properties of the GTR improve.

  • REALIZACJA USŁUGI DSR NA PRZYKŁADZIE DOMÓW JEDNORODZINNYCH
    • Paweł Bućko
    • Wiktoria Stahl
    2020 Full text Rynek Energii

    W artykule przedstawiono ideę usługi DSR, czyli reakcji strony popytowej, dla odbiorców rozproszonych. Polega ona na zmniejszeniu zapotrzebowania na energię elektryczną lub przesunięcia go w czasie. Wdrożenie usługi może w znaczny sposób wpłynąć na pracę systemu elektroenergetycznego – usługa DSR może wspomóc bilansowanie systemu elektroenergetycznego, a także pozytywnie oddziaływać na jego elastyczność, wydajność oraz stabilność. W artykule wykazano możliwy wpływ redukcji zapotrzebowania na energię elektryczną przez mieszkańców domów jednorodzinnych. Oszacowano spodziewany wpływ na obciążenie systemu skoordynowanego wykorzystania zagregowanych możliwości świadczenia usługi DSR przez większą grupę odbiorców indywidualnych w domach jednorodzinnych.