2020 - Repozytorium publikacji - Politechnika Gdańska

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Circular polarization diversity implementation for correlation reduction in wideband low-cost multiple-input-multiple-output antenna
- Ubaid Ullah
- Muath Al-hasan
- Sławomir Kozieł
- Ismail Mabrouk
2020 Pełny tekst IEEE Access
In this paper, a multiple-input-multiple-output (MIMO) antenna featuring circular polarization diversity, and designed on a common coplanar ground is presented. The proposed antenna design utilizes a coplanar waveguide (CPW) feeding technique with three parallel coplanar ground planes, and two feedlines in-between. For circular polarization (CP), quasi-loops are created by etching slots on the outermost ground planes. With this configuration, circular polarization diversity is induced in the MIMO antenna with the left-hand CP (LHCP) from one antenna and the right-hand CP (RHCP) from the other. The total footprint of the antenna radiator is only 0.78λ0 × 0.55λ0 = 0.42λ02. Experimental results show perfectly overlapping impedance and axial ratio bandwidths of 39.3% (4.5 GHz to 6.7 GHz). In addition, average in-band isolation |S21| ≤ –15 dB without any added complexity or active circuit elements. The peak realized gain of the antenna is 5.8 dBic with broadside radiation pattern in the +z- direction and envelope correlation coefficient (ECC) of 0.005. The antenna is suitable for multiple applications in the C-band that includes WLAN (5 GHz, 5.2 GHz and 5.8 GHz) and WiMAX (5.5 GHz).
Civil liability for artificial intelligence products versus the sustainable development of CEECs: which institutions matter?
- Małgorzata Godlewska
- Sylwia Morawska
- Przemysław Banasik
2020 Pełny tekst Ruch Prawniczy, Ekonomiczny i Socjologiczny
The aim of this paper is to conduct a meta-analysis of the EU and CEECs civil liability institutions in order to find out if they are ready for the Artificial Intelligence (AI) race. Particular focus is placed on ascertaining whether civil liability institutions such as the Product Liability Directive (EU) or civil codes (CEECs) will protect consumers and entrepreneurs, as well as ensure undistorted competition. In line with the aforementioned, the authors investigate whether the civil liability institutions of the EU and CEECs are based on regulations that can be adapted to the new generation of robots that will be equipped with learning abilities and have a certain degree of unpredictability in their behaviour. The conclusion presented in the paper was drawn on the basis of a review of the current literature and research on national and European regulations. The primary contribution that this article makes is to advance the current of the research concerning the concepts of AI liability for damage and personal injury. A second contribution is to show that the current civil liability institutions of the EU as well as the CEECs are not sufficiently prepared to address the legal issues that will start to arise when self-driving vehicles or autonomous drones begin operating in fully autonomous modes and possibly cause property damage or personal injury.
Coin
- Luciano Segreto
2020
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Collaborative Data Acquisition and Learning Support
- Tomasz Boiński
- Julian Szymański
2020 Pełny tekst International Journal of Computer Information Systems and Industrial Management Applications
With the constant development of neural networks, traditional algorithms relying on data structures lose their significance as more and more solutions are using AI rather than traditional algorithms. This in turn requires a lot of correctly annotated and informative data samples. In this paper, we propose a crowdsourcing based approach for data acquisition and tagging with support for Active Learning where the system acts as an oracle and repository of training samples. The paper presents the CenHive system implementing the proposed approach. Three different usage scenarios are presented that were used to verify the proposed approach.
COLLABORATIVE LEARNING ENVIRONMENT FOR ENGINEERING EDUCATION (COLED)
- Anna Grabowska
- Anna Czaja
- Ewa Kozłowska
- Jacek Zieliński
2020
Collaborative Learning Environment for Engineering Education is a European project implemented under the Erasmus + program, The main goal of 5 partners from 4 different European countries – Bulgaria, Poland, Portugal and Romania is to develop an innovative collaborative training approach, encompassing curricula related to the introduction of enterprise automation. Project activities are carried out in the period from Dctober 2018 to December 2020.
Collision-induced luminescence spectra of pyridine bombarded by 1000 eV He+ cations
- Tomasz Wąsowicz
2020 Pełny tekst Results in Physics
Here we show collision-induced luminescence spectra measured for collisions of the He+cations with thearomatic six-membered ring of the pyridine molecule (C5H5N). Distinct emission bands due to the CH(A2Δ→X2Πr;B2Σ+→X2Πr;C2Σ+→X2Πr), CN(B2Σ+→X2Σ+), C2(d3Πg→a3Πu), and NH(A3Π→X3Σ−) transitions, aswell as atomic H, He, and C lines have been observed. Apart from the He atoms, all the emitters arise from thefragmentation of the pyridine ring. The identification of the helium lines indicates a single electron transferreaction from the pyridine molecule to the He+cations. The products’intensities relative to the Hβintensityhave also been obtained and compared with the intensity ratios determined for He++ furan collisions.
Colloidal transport of lipid digesta in human and porcine small intestinal mucus
- Adam Macierzanka
- Olivia Ménard
- Didier Dupont
- Krzysztof Gutkowski
- Robert Staroń
- Lukasz Krupa
2020 Pełny tekst FOOD RESEARCH INTERNATIONAL
Small intestinal mucus transport of food-derived particulates has not been extensively studied, despite mucus being a barrier nutrients need to cross before absorption. We used complex dispersions of digesta obtained from simulated, dynamic gastrointestinal digestion of yogurt to examine the penetrability of human and porcine mucus to the particles formed of lipolysis products. Quantitative, time-lapse confocal microscopy revealed a sieve-like behaviour of the pig jejunal and ileal mucus. The digesta diffusivity decreased significantly over the first 30 min of mucus penetration, and then remained constant at ca. 5×10-12 m2s-1 (approx. 70% decrease from initial values). A non-significantly different penetrability was recorded for the ileal mucus of adult humans. The digesta diffusion rates in neonatal, jejunal mucus of 2 week old piglets were 5–8 times higher than in the three different types of adult mucus. This is the first report that validates the mucus of fully-grown pigs as a human-relevant substitute for mucus permeation studies of nutrients/bio-actives and/or complex colloidal dispersions (e.g., post-digestion food particulates, orally-administrated delivery systems).
Column base fixity in steel moment frames: Observations from instrumented buildings
- Tomasz Falborski
- Ahmad Hassan
- Amit Kanvinde
2020 JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
The rotational fixity of column base connections in Steel Moment Resisting Frames (SMRFs) strongly influences their seismic response. However, approaches for estimating base fixity have been validated only against laboratory test data. These approaches are examined based on strong motion recordings from four instrumented SMRF buildings in California to informbest practices for seismic response simulation. These buildings represent a range of structural properties, including height, layout, as well as different types of base connections and foundations. Three-dimensional simulationmodels are constructed for these buildings, including the gravity framing and nonstructural stiffness. For each building, base fixities are parametrically varied. These include pinned and fixed bases, aswell as intermediate fixities determined frompreviously developedmodels that are appropriate for simulating the specific types of base connections used in the buildings. The simulated response of these buildings is comparedwith strong motion recordings to informoptimal approaches for simulating column bases. The results indicate that: (1) for frames with exposed base plate connections, model-based estimates of base fixity result in the least error with respect to the recordings, compared to both pinned and fixed estimates, (2) for frames with embedded base connections, model-based estimates, as well as the fixed base assumption are equivalent, resulting in the least error, whereas the pinned base estimate results in large error, and (3) if simulated with the appropriate estimate of fixity as inferred fromthese observations, the simulations predict peak displacements and accelerations with good accuracy.
Combination of instrumental and qualitative descriptive analysis for evaluation of selected tonic waters quality features
- Ewa Marjańska
- Maria Szpakowska
2020 JOURNAL OF TEXTURE STUDIES
The combination of sensory and instrumental analysis was applied for quality assurance of selected tonic waters. The Quantitative Descriptive Analysis (QDA) in terms of fourteen sensory attributes (aroma, astringency, bite, burn, numbing, tongue heaviness, carbonation, mouth coating, sweet taste, sour taste, bitter taste, sweet aftertaste, sour aftertaste, bitter aftertaste) of selected tonic waters was performed by sensory experts. The results of this analysis were bound with potentiometric sensor results to elaborate mathematical models for prediction of these attributes by Partial Least Squares (PLS) analysis. Predicted values of sensory attributes were in a good agreement with those obtained by sensory experts since the standard deviation on predicted values were relatively low and determination coefficients were high. The only exception was for sweet aftertaste attribute, which model was not so well-fitted, probably due to specific interactions of tonic waters’ sweet components. This approach may ensure the standards of food quality regarding sensory parameters with diminishing assessment’s time and costs. Practical application Elaborated models based on instrumental analysis with potentiometric sensor for prediction of sensory attributes (aroma, astringency, bite, burn, numbing, tongue heaviness, carbonation, mouth coating, sweet taste, sour taste, bitter taste, sweet aftertaste, sour aftertaste, bitter aftertaste) for a group of similar tonic waters ensure the highest standards of food quality assessment in terms of consumers’ sensory preferences. These models might even diminish the role of uncomfortable and expensive, sensory analysis. Elaborated models can be successfully used for quality assessment of given tonic waters before entering the sales network. This new approach to quality assessment can be applied also for other groups of similar beverages.
Combined Long-Period Fiber Grating and Microcavity In-Line Mach–Zehnder Interferometer for Refractive Index Measurements with Limited Cross-Sensitivity
- Monika Janik
- Marcin Koba
- Krystian Król
- Predrag Mikulic
- Wojtek J. Bock
- Mateusz Śmietana
2020 Pełny tekst SENSORS
This work discusses sensing properties of a long-period grating (LPG) and microcavity in-line Mach–Zehnder interferometer (µIMZI) when both are induced in the same single-mode optical fiber. LPGs were either etched or nanocoated with aluminum oxide (Al2O3) to increase its refractive index (RI) sensitivity up to ≈2000 and 9000 nm/RIU, respectively. The µIMZI was machined using a femtosecond laser as a cylindrical cavity (d = 60 µm) in the center of the LPG. In transmission measurements for various RI in the cavity and around the LPG we observed two effects coming from the two independently working sensors. This dual operation had no significant impact on either of the devices in terms of their functional properties, especially in a lower RI range. Moreover, due to the properties of combined sensors two major effects can be distinguished—sensitivity to the RI of the volume and sensitivity to the RI at the surface. Considering also the negligible temperature sensitivity of the µIMZI, it makes the combination of LPG and µIMZI sensors a promising approach to limit cross-sensitivity or tackle simultaneous measurements of multiple effects with high efficiency and reliability.
Combined thrust radial bearing of a submarine main shaft – Design and analysis of failure
- Michał Wasilczuk
- Filip Wasilczuk
2020 Pełny tekst ENGINEERING FAILURE ANALYSIS
This paper presents an analysis of the combined thrust radial bearing of a submarine propulsion shaft. The lubrication system of the bearing is based on a fixed ring. The efficiency of the lubrication system depends on the shaft speed and temperature, which affects oil viscosity. In turn, the thrust bearing load also depends on the rotational speed of the shaft, because as the speed increases, the drag of the ship increases simultaneously, but this increase in load is accompanied by the increase of load capacity of the hydrodynamic thrust bearing. The analysis made it possible to assess the causes of bearing failure and formulate recommendations for bearing operation.
Comments on various extensions of the Riemann–Liouville fractional derivatives : About the Leibniz and chain rule properties
- Anna Szafrańska
- Jacky Cresson
2020 Communications in Nonlinear Science and Numerical Simulation
Starting from the Riemann–Liouville derivative, many authors have built their own notion of fractional derivative in order to avoid some classical difficulties like a non zero derivative for a constant function or a rather complicated analogue of the Leibniz relation. Discussing in full generality the existence of such operator over continuous functions, we derive some obstruction Lemma which can be used to prove the triviality of some operators as long as the linearity and the Leibniz property are preserved. As an application, we discuss some properties of the Jumarie’s fractional derivative as well as the local fractional derivative. We also discuss the chain rule property in the same perspective.
Communication Model Order Reduction in Hybrid Methods Involving Generalized Impedance Matrix
- Grzegorz Fotyga
- Damian Szypulski
- Rafał Lech
- Piotr Kowalczyk
2020 Pełny tekst IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
A novel strategy for the efficient analysis of frequency-domain scattering electromagnetic problems in open and closed domains is presented. A fully automatic model-order reduction technique, called the enhanced reduced-basis method, is applied to increase the efficiency of the hybrid approach, which combines the finite-element and mode-matching methods. Numerical tests show that the proposed algorithm yields reliable and highly accurate results whereas the computational time is reduced by up to one order of the magnitude.
Compact Dual-Polarized Corrugated Horn Antenna for Satellite Communications
- Manshari Saeed
- Sławomir Kozieł
- Leifur Leifsson
2020 Pełny tekst IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
In this paper, a structure and design procedure of a novel compact dual-polarized corrugated horn antenna with high gain and a stable phase center for satellite communication is presented. The antenna incorporates an Ortho-Mode Transducer (OMT), a mode converter, and a corrugated structure. The compact OMT section is designed to be fed by standard WR-75 waveguides. The proposed compact design utilizes only ten corrugated slots to yield a symmetric radiation pattern. The antenna impedance bandwidth (VSWR < 1.5) is 10.2 GHz to 15 GHz. Furthermore, the antenna exhibits 14 dBi to 17 dBi gain, a constant 30-degree HPBW radiation pattern, and less than 9mm phase center variation over the operating frequency range. The aperture diameter is 7 cm and the total antenna length is 15 cm. Due to the aforementioned features, the proposed antenna is suitable as the feed reflector for both uplink and downlink satellite communication. The design is validated numerically and experimentally.
Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study
- Shuxia Guo
- Claudia Beleites
- Ute Neugebauer
- Sara Abalde-Cela
- Nils Kristian Afseth
- Fatima Alsamad
- Suresh Anand
- Cuauhtemoc Araujo-Andrade
- Sonja Aškrabić
- Ertug Avci
- Monica Baia
- Malgorzata Baranska
- Enrico Baria
- Luis A. E. Batista de Carvalho
- Philippe de Bettignies
- Alois Bonifacio
- Franck Bonnier
- Eva Maria Brauchle
- Hugh J. Byrne
- Igor Chourpa
- Riccardo Cicchi
- Frederic Cuisinier
- Mustafa Culha
- Marcel Dahms
- Catalina David
- Ludovic Duponchel
- Shiyamala Duraipandian
- Samir F. El-Mashtoly
- David I. Ellis
- Gauthier Eppe
- Guillaume Falgayrac
- Ozren Gamulin
- Benjamin Gardner
- Peter Gardner
- Klaus Gerwert
- Evangelos J. Giamarellos-Bourboulis
- Sveinbjorn Gizurarson
- Marcin Gnyba
- Royston Goodacre
- Patrick Grysan
- Orlando Guntinas-Lichius
- Helga Helgadottir
- Vlasta Mohaček Grošev
- Catherine Kendall
- Roman Kiselev
- Micha Kölbach
- Christoph Krafft
- Sivashankar Krishnamoorthy
- Patrick Kubryck
- Bernhard Lendl
- Pablo Loza-Alvarez
- Fiona M. Lyng
- Susanne Machill
- Cedric Malherbe
- Monica Marro
- Maria Paula M. Marques
- Ewelina Matuszyk
- Carlo Francesco Morasso
- Myriam Moreau
- Howbeer Muhamadali
- Valentina Mussi
- Ioan Notingher
- Marta Z. Pacia
- Francesco S. Pavone
- Guillaume Penel
- Dennis Petersen
- Olivier Piot
- Julietta V. Rau
- Marc Richter
- Maria Rybarczyk
- Hamideh Salehi
- Katja Schenke-Layland
- Sebastian Schlücker
- Markus Schosserer
- Karin Schütze
- Valter Sergo
- Faris Sinjab
- Janusz Smulko
- Ganesh D. Sockalingum
- Clara Stiebing
- Nick Stone
- Valérie Untereiner
- Renzo Vanna
- Karin Wieland
- Jürgen Popp
- Thomas Bocklitz
2020 Pełny tekst ANALYTICAL CHEMISTRY
The variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a ‘primary’ setup and the test data are generated on ‘replicate’ setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.
Comparative Analysis of Carbon, Ecological, and Water Footprints of Polypropylene-Based Composites Filled with Cotton, Jute and Kenaf Fibers
- Jerzy Korol
- Aleksander Hejna
- Dorota Burchart-Korol
- Jan Wachowicz
2020 Pełny tekst Materials
Composites containing natural fibers are considered environmentally friendly materials which is related to the reduced use of fossil fuels and the emission of carbon dioxide compared to petroleum-based polymers. Nevertheless, a complete evaluation of their environmental impact requires a broader view. This paper presents a carbon, ecological, and water footprints assessment of polypropylene-based composites filled with cotton, jute, and kenaf fibers based on a standardized European pallet (EUR-pallet) case study. Obtained results were compared with unmodified polypropylene and composite with glass fibers. Incorporation of 30 wt% of cotton, jute, and kenaf fibers into a polypropylene matrix reduced its carbon footprint by 3%, 18%, and 18%, respectively. Regarding the ecological footprint, an 8.2% and 9.4% reduction for jute and kenaf fibers were noted, while for cotton fibers, its value increased by 52%. For these footprints, the use of jute and kenaf fibers was more beneficial than glass fibers. Nevertheless, the application of natural fibers caused a 286%, 758%, and 891% drastic increase of water footprint of the final product, which was mainly affected by cultivation and irrigation of crops. Therefore, in a holistic view, the incorporation of natural fibers into the polypropylene matrix definitely cannot be impartially considered as an environmentally friendly solution.
Comparative DEM calculations of fracture process in concrete considering real angular and artificial spherical aggregates
- Michał Nitka
- Andrzej Tejchman-Konarzewski
2020 Pełny tekst ENGINEERING FRACTURE MECHANICS
Artykuł omawia wyniki obliczeń numerycznych pękania dla betonu stosując metodę elementów dyskretnych (DEM). Beton był opisany jako materiał 4-fazowy i był poddany zginaniu. Zbadano wpływ kształtu kruszywa na proces pekania i na zalezność obciązenia od ugięcia. Wyniki dwuwymiarowe i trzywymiarowe porównano bezpośrednio z doświadczeniami. Wyniki pokazały duzy wpływ kształtu kruszywa na wyniki numeryczne.
Comparative Lipidomic Study of Human Milk from Different Lactation Stages and Milk Formulas
- Weronika Hewelt-Belka
- Dorota Garwolińska
- Michał Młynarczyk
- Agata Kot-Wasik
2020 Pełny tekst Nutrients
In this report, we present a detailed comparison of the lipid composition of human milk (HM) and formula milk (FM) targeting different lactation stages and infant age range. We studied HM samples collected from 26 Polish mothers from colostrum to 19 months of lactation, along with FM from seven brands available on the Polish market (infant formula, follow-on formula and growing-up formula). Lipid extracts were analysed using liquid chromatography coupled to high-resolution mass spectrometry (LC–Q-TOF–MS). We found that the lipid composition of FM deviates significantly from the HM lipid profile in terms of qualitative and quantitative differences. FM had contrasting lipid profiles mostly across brands and accordingly to the type of fat added but not specific to the target age range. The individual differences were dominant in HM; however, differences according to the lactation stage were also observed, especially between colostrum and HM collected in other lactation stages. Biologically and nutritionally important lipids, such as long-chain polyunsaturated fatty acids (LC-PUFAs) containing lipid species, sphingomyelines or ether analogues of glycerophosphoethanoloamines were detected in HM collected in all studied lactation stages. The observed differences concerned all the major HM lipid classes and highlight the importance of the detailed compositional studies of both HM and FM.
Comparative study of a bottoming SRC and ORC for Joule–Brayton cycle cooling modular HTR exergy losses, fluid-flow machinery main dimensions, and partial loads
- Tomasz Kowalczyk
- Janusz Badur
- Paweł Ziółkowski
2020 Pełny tekst ENERGY
Energy conversion efficiency increase in power plants with high-temperature gas-cooled reactors via implementation of the bottoming cycle was investigated under nominal and minimal thermal load of a high-temperature reactor (HTR). Heat transfer surface area and turbine outlet volumetric flow rate in bottoming cycles was also investigated. Water and two low-boiling point working fluids (ammonia and ethanol) were analyzed. Analyzed thermodynamic cycles consisted of a closed Joule-Brayton cycle with helium as working medium, which was investigated in configurations with heat regeneration, compressor intercoolers, and in a simple design. Organic versus steam Rankine cycles were compared; low-boiling point fluids under supercritical conditions in some configurations provide higher cycle energy efficiency than the gas-steam cycle. Volumetric flow rates in the last turbine stages were reduced against the steam turbine to 38% and 0.8% with ethanol and ammonia, respectively. The steam Rankine cycle configuration provided the smallest heat transfer surface increase compared with the base cycle.
Comparative Study of Integer and Non-Integer Order Models of Synchronous Generator
- Szymon Racewicz
- Filip Kutt
- Michał Michna
- Łukasz Sienkiewicz
2020 Pełny tekst ENERGIES
This article presents a comparison between integer and non-integer order modelling of a synchronous generator, in the frequency domain as well as in the time domain. The classical integer order model was compared to one containing half -order systems. The half-order systems are represented in a Park d-q axis equivalent circuit as impedances modelled by half-order transmittances. Using a direct method based on the approximation of the half-order derivatives by the Grünwald–Letnikov definition, a state-space equation system was solved. For both models, a computational program written in Matlab software was used. For the purpose of time domain simulation, the machine models were connected to an electric load composed of an RL circuit. To validate and compare both models, simulation results of a three-phase short-circuit and a no-load voltage recovery were compared with corresponding measurements performed on a solid salient-pole synchronous generator of 125 kVA.