2019 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2019

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Distributed Architectures for Intensive Urban Computing: A Case Study on Smart Lighting for Sustainable Cities
- Higinio Mora
- Jesus Peral
- Antonio Ferrandez
- David Gil
- Julian Szymański
2019 Full text IEEE Access
New information and communication technologies have contributed to the development of the smart city concept. On a physical level, this paradigm is characterised by deploying a substantial number of different devices that can sense their surroundings and generate a large amount of data. The most typical case is image and video acquisition sensors. Recently, these types of sensors are found in abundance in urban spaces and are responsible for producing a large volume of multimedia data. The advanced computer vision methods for this type of multimedia information means that many aspects can be dynamically monitored, which can help implement value-added applications in the city. However, obtaining more elaborate semantic information from these data poses significant challenges related to a large amount of data generated and the processing capabilities required. This work aims to address these issues by using a combination of cloud computing technologies and mobile computing techniques to design a three-layer distributed architecture for intensive urban computing. The approach consists of distributing the processing tasks among a city’s multimedia acquisition devices, a middle computing layer, known as a cloudlet, and a cloud-computing infrastructure. As a result, each part of the architecture can now focus on a small number of tasks for which they are especially designed, and data transmission communication needs are significantly reduced. To this end, the cloud server can hold and centralise the multimedia analysis of processed results from the lower layers. Finally, a case study on smart lighting is described to illustrate the benefits of using the proposed model in smart city environments.
DISTRIBUTION OF FLOWS IN A CHANNEL NETWORK UNDER STEADY FLOW CONDITIONS
- Dariusz Gąsiorowski
- Wojciech Artichowicz
2019 Full text Acta Scientiarum Polonorum Formatio Circumiectus
The article presents an algorithm for calculating the distribution of flow in a junction of open channel network under steady flow conditions. The article presents a simplified calculation algorithm used to estimate the distribution of flow in a network of channels under steady flow conditions. The presented algorithm is based on the continuity equation and a simplified energy equation. To describe the relationship between the depth of water and the flow rate, the Manning’s equation was used to express discharge in the main channel, whereas in case of other channels, with hydraulic structures, appropriate equations describing the flow over a weir and through the culverts were used. Substitution of the abovementioned relationships with the continuity equation leads to a non-linear algebraic equation with respect to the water level. The resulting equation can be solved with iterative numerical methods. Calculation example using the proposed algorithm was carried out for the hydraulic system located on the Strzyża stream in Gdańsk. The presented approach can be an alternative to analytical-graphic method and it does not require formulation of the boundary problem for the
Distribution Transformer with Multi-Zone Voltage Regulation for Smart Grid System Application
- Ryszard Strzelecki
- Wojciech Matelski
- Robert Małkowski
- Valentin Tomasov
- Leszek Wolski
- Antoni Krahel
2019 Full text
The article presents four concepts of the multi-zone voltage regulation (MZVR) system. It is a combination of a distribution transformer with an on-load tap-changer, for step voltage regulation, and a power electronic converter, dimensioned for a fraction of MZVR power, realizing continuous voltage regulation, supplemented by a special switch, the so-called bypass. This allows voltage regulation at high resolution, wide range and with high dynamics and increased reliability. The work contains selected computer simulation results of the continuous regulation system, and considerations about extending the MZVR continuous voltage regulation range and its power level.
DME as alternative fuel for compression ignition engines – a review
- Denys Stepanenko
- Zbigniew Kneba
2019 Full text Combustion Engines
The ecological issues and the depletion of crude oil, has led the researchers to seeking for non-petroleum based alternative fuels, along with more advanced combustion technologies, and after-treatment systems. The use of clean alternative fuels is the one of the most perspective method that aiming at resolving of the said issues. One of the promising alternative fuels that can be used as a clean highefficiency compression ignition fuel with reduced of toxic emissions is dimethyl ether (DME). Moreover, it can be produced from various feedstocks such as natural gas, coal, biomass and others. This article describes the properties and the potential of DME application on the combustion and emission reduction characteristics of the compression ignition engines.
DMSO hydration redefined: Unraveling the hydrophobic hydration of solutes with a mixed hydrophilic–hydrophobic characteristic
- Aneta Panuszko
- Piotr Bruździak
- Maciej Śmiechowski
- Marcin Stasiulewicz
- Joanna Stefaniak
- Janusz Stangret
2019 Full text JOURNAL OF MOLECULAR LIQUIDS
Hydrophobic hydration of solutes with a mixed hydrophilic--hydrophobic characteristics is still poorly understood. This is because both experimental and theoretical methods find it difficult to see the ice-like water structure around the nonpolar solute groups, unlike hydrogen bonds with the hydrophilic groups. In order to unravel this problem, we have investigated DMSO hydration by means of infrared spectroscopy and theoretical methods, namely DFT, ONIOM calculations and AIMD simulations, which allowed us to redefine its hydration. In dilute DMSO solutions the clathrate-like water is formed around the DMSO molecule, supported by interactions of water molecules with the methyl hydrogens (the blue-shifted hydrogen bonds). The cage is constructed by water molecules that form hydrogen bonds of the comparable energy and length with the SO group and between water molecules. When the construction of the cage is completed, DMSO molecule partially regains its rotational freedom inside. Strong hydrogen bonds within the frame are masked by the relatively small population of weakened hydrogen bonds of water molecules in the vicinity of the SO group, due to the improper fit to the bulk water of water molecules hydrogen bonded to the oxygen atom of DMSO. We also propose a new explanation of the highly non-ideal mixing behavior of aqueous DMSO solutions at the eutectic point, as the positive excess entropy of the equimolar amounts of molecular complexes distinguished in the system.
DNA Methylation Changes Induced by Redox-Active Compounds—Choosing the Right PCR-Based Method
- Patrycja Jakubek
- Jovana Rajić
- Monika Baranowska
- Melita Vidaković
- Agnieszka Bartoszek-Pączkowska
- Jacek Namieśnik
2019 Full text Proceedings
The impact of catechins on the expression profile of redox-related genes in HT29 cell line has been studied recently by our group using Oxidative Stress RT2 Profiler PCR Array. Within the examined panel of 84 genes, the down-regulation of SRXN1 gene was unique among other up-regulated genes. We hypothesized that the observed down-regulation resulted from DNA methylation and have exploited this observation to choose the proper strategy to monitor the changes in DNA methylation patterns incurred by dietary antioxidants. The current study verified two PCR-based approaches.
Do online reviews reveal mobile application usability and user experience? The case of WhatsApp
- Anna Baj-Rogowska
- Paweł Weichbroth
2019 Full text Annals of Computer Science and Information Systems
The variety of hardware devices and the diversity of their users imposes new requirements and expectations on designers and developers of mobile applications (apps). While the Internet has enabled new forms of communication platform, online stores provide the ability to review apps. These informal online app reviews have become a viral form of electronic wordof-mouth (eWOM), covering a plethora of issues. In our study, we set ourselves the goal of investigating whether online reviews reveal usability and user experience (UUX) issues, being important quality-in-use characteristics. To address this problem, we used sentiment analysis techniques, with the aim of extracting relevant keywords from eWOM WhatsApp data. Based on the extracted keywords, we next identified the original users’ reviews, and individually assigned each attribute and dimension to them. Eventually, the reported issues were thematically synthesized into 7 attributes and 8 dimensions. If one asks whether online reviews reveal genuine UUX issues, in this case, the answer is definitely affirmative.
Doktorant PG – Jutronauta w NASA
- Adam Dąbrowski
2019 Full text Pismo PG
Mgr inż. Adam Dąbrowski, doktorant i asystent na Wydziale Mechanicznym, został laureatem konkursu Gazety Wyborczej „Jutronauci. Bilet za horyzont”, w ramach którego odbył staż w Jet Propulsion Laboratory (JPL), laboratorium NASA w Pasadenie w Kalifornii.
Dokumentacja oraz wnioski z badań prototypowego stropu typu filigran z wkładką styropianową dla firmy Strobud Prefabrykacja sp. z o.o.
- Krystyna Nagrodzka-Godycka
- Marek Wesołowski
- Jarosław Kondrat
- Maciej Solarczyk
2019
Niniejsze opracowanie stanowi dokumentację oraz wnioski z badań prototypowego stropu typu filigran z wkładką styropianową.
Domination subdivision and domination multisubdivision numbers of graphs
- Magda Dettlaff
- Joanna Raczek
- Jerzy Topp
2019 Full text Discussiones Mathematicae Graph Theory
The domination subdivision number sd(G) of a graph G is the minimum number of edges that must be subdivided (where an edge can be subdivided at most once) in order to increase the domination number of G. It has been shown [10] that sd(T)<=3 for any tree T. We prove that the decision problem of the domination subdivision number is NP-complete even for bipartite graphs. For this reason we define the domination multisubdivision number of a nonempty graph G as a minimum positive integer k such that there exists an edge which must be subdivided k times to increase the domination number of G. We show that msd(G)<=3 for any graph G. The domination subdivision number and the domination multisubdivision number of a graph are incomparable in general, but we show that for trees these two parameters are equal. We also determine the domination multisubdivision number for some classes of graphs.
Doped Nanocrystalline Diamond Films as Reflective Layers for Fiber-Optic Sensors of Refractive Index of Liquids
- Monika Kosowska
- Daria Majchrowicz
- Kamatchi J Sankaran
- Mateusz Ficek
- Ken Haenen
- Małgorzata Szczerska
2019 Full text Materials
This paper reports the application of doped nanocrystalline diamond (NCD) films—nitrogen-doped NCD and boron-doped NCD—as reflective surfaces in an interferometric sensor of refractive index dedicated to the measurements of liquids. The sensor is constructed as a Fabry–Pérot interferometer, working in the reflective mode. The diamond films were deposited on silicon substrates by a microwave plasma enhanced chemical vapor deposition system. The measurements of refractive indices of liquids were carried out in the range of 1.3 to 1.6. The results of initial investigations show that doped NCD films can be successfully used in fiber-optic sensors of refractive index providing linear work characteristics. Their application can prolong the lifespan of the measurement head and open the way to measure biomedical samples and aggressive chemicals.
Doraźna nośność słupów o przekroju kołowym z rur FRP wypełnionych betonem Badania, teoria, obliczanie
- Marcin Abramski
2019
Praca ma charakter monografii opisującej aktualny stan wiedzy z zakresu badań, teorii i projektowania słupów CFFT (concrete-filled fiber-reinforced polymer tube). Celem prowadzonych przez autora prac studialnych i badań własnych, w tym eksperymentalnych, jest szczegółowa analiza doraźnej nośności i zachowania się słupów CFFT poddanych ściskaniu osiowemu i mimośrodowemu. W pierwszym rozdziale wyjaśniono motywację autora do podjęcia tej tematyki, przedstawiając ją jednocześnie jako niszę badawczą. W rozdziale drugim opisano na konkretnych przykładach najbardziej odpowiednie dla słupów CFFT obszary zastosowań: jako obiekty infrastruktury morskiej i mostowej. Rozdziały trzeci i czwarty mają na celu przedstawienie aktualnego stanu wiedzy, odpowiednio na temat zachowania betonu skrępowanego w słupach z rur stalowych lub kompozytowych wypełnianych betonem (concrete filled tube) oraz uwzględniania efektów drugiego rzędu w obliczaniu nośności słupów z betonu. W rozdziale trzecim przywołano wyselekcjonowane, zdaniem autora – mające charakter najbardziej poznawczy badania obce i opatrzono je komentarzem. W rozdziale czwartym natomiast wzięto pod uwagę normatywy projektowania słupów z betonu: przede wszystkim europejskie (Eurokody), ale także amerykańskie, międzynarodowe i wybrane krajowe. W rozdziale piątym, najbardziej obszernym, przedstawiono badania eksperymentalne, w przeważającej części własne, poświęcone nośności i zachowaniu słupów CFFT ściskanych osiowo lub mimośrodowo. W całości własne w tym rozdziale są obszerne badania eksperymentalne własności kompozytów FRP rur, których użyto do wykonania wspomnianych słupów. Dla trzech zastosowanych kompozytów wyznaczono podstawowe stałe materiałowe, wymagane w teorii liniowej sprężystości. Ponieważ były to badania nietypowe dla inżynierii budowlanej, zastosowano procedury nie tylko normowe, lecz także własne, zaproponowane przez autora. Wszystkie przeprowadzone badania opisane w pracy pozwoliły na sformułowanie propozycji metody wyznaczania doraźnej nośności słupów CFFT. Przedstawiono ją w rozdziale szóstym. Opracowując metodę, wzorowano się przede wszystkim na Eurokodach oraz na amerykańskim normatywie poświęconym projektowaniu słupów CFFT. Dla zaproponowanej metody opracowano program komputerowy i przy jego użyciu sprawdzono zgodność wyników nośności obliczonych metodą autorską z wynikami eksperymentów. Na zakończenie nakreślono kierunki dalszych badań nad słupami CFFT.
Drewniane więźby dachowe żuławskich domów podcieniowych typu III – badania, stan zachowania, analiza
- Tomasz Zybała
2019 Full text Budownictwo i Architektura
Zabytkowe domy podcieniowe ujścia Delty Wisły były obiektem zainteresowań wielu badaczy, jednak ich prace koncentrowały się głównie na aspektach historyczno-architektonicznych. Nie ma publikacji skupiających się na szczegółach i dokładnych analizach ustrojów budowlanych dla tej grupy historycznych obiektów. Artykuł jest rezultatem badań terenowych, kwerendy archiwalnej i obliczeń wykonanych przez autora. W pracyprzeanalizowano konstrukcje więźb dachowych zachowanych domów podcieniowych typu III.Autor wykonał zestawienia elementów nośnych dachów, połączeń ciesielskich, kątów nachylenia krokwi, opisał także stan zachowania wiązarów dachowych.Praca zawiera również obliczenia średniej objętości materiału konstrukcyjnego wiązara więźby dachowej przypadającego na metr kwadratowy rzutu połaci dachowej.
DREWNO i DOM. Drewno w architekturze mieszkalnej dawnego Wejherowa
- Anita Jaśkiewicz-Sojak
- Kurpiewski Maciej
2019
Drewno jest jednym z podstawowych materiałów budowlanych, który bardzo często był wykorzystywany w budownictwie minionych okresów historycznych. Drewno stosowano zarówno jako materiał konstrukcji budynków lub ich części, jak i tworzywo do kształtowania poszczególnych elementów i detalu architektonicznego. Wystawa przedstawia różne sposoby wykorzystania tego materiału budowlanego w architekturze mieszkaniowej Wejherowa w przeszłości. Rozważania na ten temat zostały zilustrowane archiwalnymi fotografiami i kartami pocztowymi dawnego Wejherowa, powstałymi w końcu XIX i w pierwszej połowie XX wieku. Ilustracjom towarzyszą także eksponaty, drewniane elementy zabytkowych budynków, które udało się zabezpieczyć i zachować. Są one dowodami na kruchość i nietrwałość drewna oraz świadczą o tym, że materialne dziedzictwo drewniane powoli znika z miejskiego krajobrazu i - paradoksalnie - powoli przekształca się w dziedzictwo niematerialne.
Droga S7 Koszwały – Kazimierzowo – geotechniczne aspekty inwestycji.
- Grzegorz Horodecki
2019 Magazyn Autostrady
W artykule przedstawiono ogólne informacje dotyczące geotechnicznych aspektów projektu i realizacji drogi S7 na odcinku Koszwały – Kazimierzowo, ze szczególnym uwzględnieniem rozwiązań z zastosowaniem technologii zamkniętego materaca odciążającego z kruszywa lekkiego – keramzytu geotechnicznego. Przedstawiono metody wzmocnienia podłoża przyjęte na etapie projektu oraz realizacji wraz z monitoringiem geotechnicznym.
Drop-coating deposition surface-enhanced Raman spectroscopy on silver substrates for biofluid analysis
- Maciej Wróbel
- Zufang Huang
- Soumik Siddhanta
- Ishan Barman
2019 Full text
Utilization of surface-enhanced Raman spectroscopy as a measurement technique is of particular interest in biodetection due to its superb chemical specificity and high sensitivity. The use of SERS substrates further improve this method by massive enhancement of the molecule Raman spectrum, permitting very low levels of detection. Therefore it is important to seek for new ways to develop reliable substrates, which are quickly and easily manufactured at a low cost. This paper describes the development of a simple and cost-effective substrate for the SERS detection. The substrate is synthesized from a silver ink on the glass, and its utilization for biodetection is shown. The hydrophobicity of the substrate permits the pre-concentration benefit of the drop-coating deposition, by the formation of the coffee-ring. This allows to achieve lower limits of detection, by effectively measuring areas with higher concentration of measured molecules than the initial sample. However, the different properties of the medium, such as the influence of protein types and amounts, may influence the ring formation mechanics, thus effectively changing the pre-concentration of the target analyte.
Dual-band antenna with improved gain for WLAN and ISM applications
- Adrian Bekasiewicz
- Sławomir Kozieł
2019 ELECTRONICS LETTERS
In this Letter, a dual-band antenna with an improved gain is proposed. The structure features 9.7 and 10.4 dBi gain within 2.4 GHz to 2.5 GHz and 5 GHz to 6 GHz bands, respectively. This makes it suitable for WLAN and ISM applications. The structure comprises an asymmetrical pair of radiators and slots suspended over a reflector. The antenna is optimised in a two-stage process using a trust-region-based gradient search algorithm. The design is compared to the state-of-the-art radiators reported in the literature. The numerical results are validated through measurements of the fabricated antenna prototype.
DWUKIERUNKOWY PRZEWODOWY SYSTEM TRANSMISJI MOWY PRZY WYKORZYSTANIU TECHNOLOGII BPL
- Przemysław Jedlikowski
- Grzegorz Debita
- Przemysław Falkowski-Gilski
- Marcin Habrych
- Bogdan Miedziński
- Jan Wandzio
2019 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Monitorowanie pracowników w środowisku podziemnym jest niezwykle ważnym zadaniem. Z uwagi na możliwe zagrożenia, konieczne jest opracowanie niezawodnego systemu komunikacji głosowej pomiędzy personelem a przełożonym. Dzięki wysokiej odporności na uszkodzenia mechaniczne, kable zasilające pracujące w technice BPL (Broadband over Power Line) wydają się doskonałym rozwiązaniem. W pracy przedstawiono w pełni funkcjonalny dwukierunkowy system transmisji mowy. Testy przeprowadzono w warunkach rzeczywistych, obejmujących szyb wydobywczy.
Dynamic Bankruptcy Prediction Models for European Enterprises
- Tomasz Korol
2019 Full text Journal of Risk and Financial Management
This manuscript is devoted to the issue of forecasting corporate bankruptcy. Determining a firm’s bankruptcy risk is one of the most interesting topics for investors and decision-makers. The aim of the paper is to develop and to evaluate dynamic bankruptcy prediction models for European enterprises. To conduct this objective, four forecasting models are developed with the use of four different methods—fuzzy sets, recurrent and multilayer artificial neural network, and decision trees. Such a research approach will answer the question of whether changes in indicators are relevant predictors of a company’s coming financial crisis because declines or increases in values do not immediately indicate that the company’s economic situation is deteriorating. The research relies on two samples of firms—the learning sample of 50 bankrupt and 50 non-bankrupt enterprises and the testing sample of 250 bankrupt and 250 non-bankrupt firms.
Dynamic modeling of non-cylindrical curved viscoelastic single-walled carbon nanotubes based on the second gradient theory
- Mohammad Malikan
- Van Bac Nguyen
- Rossana Dimitri
- Francesco Tornabene
2019 Full text Materials Research Express
This paper is devoted to the theoretical study of the dynamic response of non-cylindrical curved viscoelastic single-walled carbon nanotubes (SWCNTs). The curved nanotubes are largely used in many engineering applications, but it is challenging in understanding mechanically the dynamic response of these curved SWCNTs when considering the influences of the material viscosity. The viscoelastic damping effect on the dynamic response is considered here by using the Kelvin-Voigt viscoelastic model. A modified shear deformation beam theory is here employed to formulate the governing partial differential equations. When the SWCNTs are considered in a small scale model, quantum impacts are important for a correct evaluation of the mechanical response of the nanosystem. This is here investigated by embedding the well-known nonlocal strain gradient approach into the governing equations. The extracted equations are solved by utilizing the Galerkin analytical approach in which the governing partial differential equations are reduced to ordinary differential equations and numerical findings are achieved for various boundary conditions. In order to evaluate the efficiency of the proposed theory, the outcomes in terms of natural frequencies of the vibrating nanotubes are verified with respect to the available literature. It follows a vast systematic study, where several parameters are varied to investigate the influences of geometrical properties involving different polygons of the SWCNTs on the dynamic response.