2020 - Repozytorium publikacji - Politechnika Gdańska

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Forecasting risks and challenges of digital innovations
- Marcin Sikorski
2020
Forecasting and assessment of societal risks related to digital innovation systems and services is an urgent problem, because these solutions usually contain artificial intelligence algorithms which learn using data from the environment and modify their behaviour much beyond human control. Digital innovation solutions are increasingly deployed in transport, business and administrative domains, and therefore, if abused by a malicious human activity or by a technical malfunction, may pose serious threats to public and to society. Contrary to enthusiastic promotional messages from business and industry circles, the public is increasingly concerned by numerous examples of abuse of DIs, including hacking of specific digital solutions, misuse of social media for destructive activities, or digital addiction spreading among young users. Although certainly not a new concept, the issue of designers’ responsibility for the social impact of their creations is becoming ever more actual, as a well as the search for preventive technological, cultural and institutional measures.This chapter presents early results of testing a new approach to forecasting and prioritizing societal risks associated with deploying digital innovations. This approach – termed the RADI methodology – features two new elements: combining small expert panels with AHP-processed human assessments, and a relationship matrix visually mapping identified threats with available preventive policies, including the Socially Responsible Design approach. Although in an early version, the RADI methodology has been shown to be useful in guiding expert panels in profiling arrays of interventions to be undertaken by specific institutions against potential damage caused by non-validated and non-certified digital innovations.
Formaldehyde detection with chemical gas sensors based on WO3 nanowires decorated with metal nanoparticles under dark conditions and UV light irradiation
- Benachir Bouchikhi
- Tomasz Chludziński
- Tarik Saidi
- Janusz Smulko
- Nezha El Bari
- He Wen
- Radu Ionescu
2020 Pełny tekst SENSORS AND ACTUATORS B-CHEMICAL
We report results of formaldehyde gas (CH2O) detection under dark conditions and UV light irradiation with pristine tungsten trioxide nanowires (WO3 NWs) and metal nanoparticles decorated WO3 NWs gas sensing layers. The resistive layers were deposited by one step aerosol assisted chemical vapor deposition (AACVD) on commercial alumina substrates with 10-pair interdigitated platinum electrodes. The elaborated gas sensors, based on pristine WO3 and on WO3 decorated with Au, Pt, Au/Pt, Ni and Fe nanoparticles, were investigated towards three concentrations of formaldehyde gas (5, 10 and 15 ppm) under dark conditions and under UV light irradiation at the wavelength of 394 nm. Two main effects were observed: firstly, under UV light irradiation the response time for CH2O desorption was significantly reduced with the exception of the nanomaterial with Fe NPs dopant; secondly, the gas induced baseline shift was reduced under UV light irradiation conditions. These results can be explained by the additional energy induced by the UV light, accelerating the adsorption-desorption processes. The results obtained confirmed that both the decoration of WO3 NWs with selected metal nanoparticles as well as sensors operation under UV light irradiation are a practical and affordable way to enhance gas sensing towards formaldehyde detection, although both strategies applied together did not introduce an amplified synergetic effect.
─ Formation of a state institution on the basis of a process analysis - The concept of the institution of cadastre
- Nogalski Bogdan
- Adam Klimek
- Joanna Czerska
- Agnieszka Szpitte
2020
Modification of the structures of public administration encounters major obstacles. Institutional changes are difficult to introduce due to their complexity and broad impact. Non-substantial (political) factors are of importance as well. The resistance to change is aggravated by how difficult it is for decision-makers to assess the impact of the changes that are proposed. We present a method of handling such issues based on the process approach. It allows one to take a critical look at functioning state institutions and to develop draft changes. We discuss its application in the creation of concepts of institutional changes relying on the example of the administration segment, which handles geodesy and cartography in Poland. The study consists of three parts: the introduction, which defines the purpose of the work and presents the issues, method of conducting work, tools used, and the subject of research; the second part, in which the process of creating a cadastre concept is described based on the presented method; and the third part, namely the summary.
Formation of the hollow nanopillar arrays through the laser-induced transformation of TiO2 nanotubes
- Jakub Wawrzyniak
- Jakub Karczewski
- Piotr Kupracz
- Katarzyna Grochowska
- Emerson Coy
- Adam Mazikowski
- Jacek Ryl
- Siuzdak Katarzyna
2020 Pełny tekst Scientific Reports
In the following article, we present a simple, two-step method of creating spaced, hollow nanopillars, from the titania nanotube arrays via pulsed laser-treatment. Due to the high ordering of the structure, the prepared material exhibits photonic properties, which has been shown to increase the overall photoefficiency. The optical and morphological changes in the titania nanotubes after pulsed laser-treatment with 532, 355, and 266 nm wavelengths in the 10–50 mJ/cm2 fluence range are studied. The investigation reveals, that by using appropriate wavelength and energy, the number of surface defects, geometrical features, or both can be tailored.
Fotodachówka z systemem chłodzenia jako hybrydowy panel fotowoltaiczny – badania eksperymentalne
- Jan Wajs
- Aleksandra Gołąbek
2020
Panel fotowoltaiczny w formie dachówki, zbudowany z monokrystalicznych ogniw krzemowych, może tworzyć system solarny dla budownictwa, określany jako technologia Building-Integrated Photovoltaic (BIPV). Ze względu na spadek sprawności elektrycznej ogniw fotowoltaicznych wraz ze wzrostem temperatury pracy, poszukuje się metod ich skutecznego chłodzenia. Pozyskane w ten sposób ciepło można dodatkowo wykorzystać w innych procesach, np. dla potrzeb budownictwa mieszkaniowego lub budownictwa użyteczności publicznej. W artykule przedstawiono wyniki własnych badań z udziałem fotowoltaicznej dachówki chłodzonej powietrzem, stanowiącej hybrydowy panel fotowoltaiczny. Zaprezentowano stanowisko badawcze, wyposażone w symulator promieniowania słonecznego, oraz metodykę prowadzenia badań eksperymentalnych. Dokonano oceny wpływu warunków chłodzenia na temperaturę pracy dachówki oraz jej parametry elektryczne. W zakresie badań cieplnych, oszacowano gęstość pozyskanego strumienia ciepła, przy wydatkach objętościowych powietrza 1 i 4 m3/h, przepływającego w kanałach o wysokości 25 oraz 51 mm. Chłodzenie panelu fotowoltaicznego skutkowało maksymalnym wzrostem sprawności elektrycznej o 12,6%, a uzyskana całkowita sprawność konwersji promieniowania przekroczyła 32%.
fotografia pt. 'relacje nadzwyczajne'
- Agnieszka Kurkowska
2020
Pandemia wymusiła relacje nadzwyczajne. Międzyludzkie i ludzko-przyrodnicze. Fotografia dokumentuje cykl instalacji artystycznych w przestrzeni lasu. Bohaterami dokumentowanych fotograficzne sytuacji są schematyczne zarysowane postaci ludzkie, w niecodziennej skali, niecodziennych ulokowaniach ale codziennych 'ułożeniach'. To czyni te relacje nadzwyczajnymi, choć pandemiczny kontekst społecznej izolacji ujmuje im semantyczny wydźwięk świąteczny. Utęskniona relacja z przyrodą paradoksalnie czyni te wykreowane spotkania wyjątkowymi.
FPGA Based Real Time Simulations of the Face Milling Process
- Michał Mazur
- Marek Galewski
- Krzysztof Kaliński
2020 Pełny tekst IEEE Access
The article presents a successful implementation of the milling process simulation at the Field-Programmable Gate Array (FPGA). By using FPGA, very rigorous Real-Time (RT) simulation requirements can be met. The response time of the FPGA simulations is significantly reduced, and the time synchronization is better than in a typical RT system implemented in software. The FPGA-based approach is characterized by enormous flexibility when it comes to input and output operations that can be implemented deterministically in RT. Complex simulation software has been implemented using the High Level Synthesis technique, which is a relatively easy and fast approach for FPGA programming without using complex Hardware Description Languages. The hardware functions are based on procedures written in high-level C programming language. The mathematical descriptions of simulations, results of computer simulations, Hardware-in-the-Loop Simulation experiments, and real experiments are presented. The approach presented in this paper can be used to simulate the dynamics of various mechatronic systems.
FPGA-Based System for Electromagnetic Interference Evaluation in Random Modulated DC/DC Converters
- Hermes Loschi
- Piotr Lezynski
- Robert Smolenski
- Douglas Nascimento
- Wojciech Śleszyński
2020 Pełny tekst ENERGIES
Field-Programmable Gate Array (FPGA) provides the possibility to design new “electromagnetic compatibility (EMC) friendly” control techniques for power electronic converters. Such control techniques use pseudo-random modulators (RanM) to control the converter switches. However, some issues connected with the FPGA-based design of RanM, such as matching the range of fixed-point numbers, might be challenging. The modern programming tools, such as LabVIEW, may facilitate the design process, but there are still fixed-point operations and limitations in arithmetic operations. This paper presents the design insights on the FPGA-based EMC friendly control system for DC/DC converter. Probability density functions (PDF) are used to analyse and improve pseudo-random algorithms. The theoretical algorithms, hardware details and experimental results are presented and discussed in terms of conducted electromagnetic interference emission.
Framework for Integration Decentralized and Untrusted Multi-vendor IoMT Environments
- Andrzej Sobecki
- Julian Szymański
- David Gil
- Higinio Mora
2020 Pełny tekst IEEE Access
Lack of standardization is highly visible while we use historical data sets or compare our model with others that use IoMT devices from different vendors. The problem also concerns the trust in highly decentralized and anonymous environments where sensitive data are transferred through the Internet and then are analyzed by third-party companies. In our research we propose a standard that has been implemented in the form of framework that allows describing requirements for methods and platforms that collect, manage, share, and perform data analysis form the Internet of Medical Things in order to increase trust. Further, we can distinguish two types of IoMT devices: passive and active. Passive devices measure some parameters of the body and save them in databases. Active devices have the functionality of passive devices and moreover, they can act in a defined way, eg.: inject directly into the patient's body some elements such as a medicament, electric signals to the nervous system, stimulus pacemaker, etc. Nevertheless how to create a safe and transparent environment for using data active sensors, developing safe ML models, performing medical decisions based on the created models and finally deploy this decision to the specified device. While the IoMT devices are used in real-life, professional healthcare the control system should offer tools for backtracking decisions, allowing e.g. to find who made a mistake, or which event caused a particular decision. Our framework provides backtracking in the IoMT environment in which for each medical decision supported by ML models we can prove which sensor sends the data, which data was used to create prediction/recommendation, what prediction was produced, who and when use it, what medical decision was made by who. We propose a vendor transparency framework for each IoMT devices and ML models that will process the medical data in order to increase patient's privacy and prevent for eventual data leaking.
Framework for Structural Health Monitoring of Steel Bridges by Computer Vision
- Adam Marchewka
- Patryk Ziółkowski
- Victor Aguilar-vidal
2020 Pełny tekst SENSORS
The monitoring of a structural condition of steel bridges is an important issue. Good condition of infrastructure facilities ensures the safety and economic well-being of society. At the same time, due to the continuous development, rising wealth of the society and socio-economic integration of countries, the number of infrastructural objects is growing. Therefore, there is a need to introduce an easy-to-use and relatively low-cost method of bridge diagnostics. We can achieve these benefits by the use of Unmanned Aerial Vehicle-Based Remote Sensing and Digital Image Processing. In our study, we present a state-of-the-art framework for Structural Health Monitoring of steel bridges that involves literature review on steel bridges health monitoring, drone route planning, image acquisition, identification of visual markers that may indicate a poor condition of the structure and determining the scope of applicability. The presented framework of image processing procedure is suitable for diagnostics of steel truss riveted bridges. In our considerations, we used photographic documentation of the Fitzpatrick Bridge located in Tallassee, Alabama, USA.
Free Vibration of Flexomagnetic Nanostructured Tubes Based on Stress-driven Nonlocal Elasticity
- Mohammad Malikan
- Victor Eremeev
2020 Pełny tekst
A framework for the flexomagneticity influence is here considered extending the studies about this aspect on the small scale actuators. The developed model accommodates and composes linear Lagrangian strains, Euler-Bernoulli beam approach as well as an extended case of Hamilton’s principle. The nanostructured tube should subsume and incorporate size effect; however, for the sake of avoiding the staggering costs of experiments, here, via stress-driven nonlocal elasticity theory, the desired influence is captured. A given section is dedicated to reveal the accuracy of the achieved model. In view of solution, the numerical results are generated analytically. We receive the conclusion that in nanoscale tubes the diameter can affect fundamentally the performance of the flexomagnetic effect.
Frequency Diagnostics of Transformer Insulating Parameters
- Peter Brnacal
- Miroslav Gutten
- Cefer Viktor
- Daniel Korenciak
- Leszek Jarzębowicz
2020
In the article is presented experimental analysis and diagnostics of insulating system oil-paper for power transformers, mainly by progressive frequency method – dielectric spectroscopy. In the 1-st part of the article is described base theory about measurement and diagnostics insulating part (oil and paper) of power transformers. In the 2-nd part of article is described measuring method of insulating frequency diagnostics - frequency domain spectroscopy (FDS). This method is used for analysis insulating condition of highvoltage equipment with insulating oil-paper. In the 3-st part of article is described measuring time method of insulating diagnostics - return voltage measurement (RVM). This method is used for analysis of condition of paper moisture of high-voltage equipment. The both measuring methods are unique in terms of analysis of insulating system of oil power transformers. In comparison with other methods, the RVM and FDS methods it is possible comparison and evaluate the moisture state of the dielectric paper of the power transformer with high reliability and accurate. Their reliability in determining moisture in paper was shown by determining the same result (3.5%) on the same measured distribution transformer.
Functional phase bistability in a nanocrystalline RbMn[Fe(CN)6] thin film fabricated by matrix-assisted laser evaporation
- Dominik Maskowicz
- Mirosław Sawczak
- Rafał Jendrzejewski
- Maria Gazda
- Hiroko Tokoro
- Shin-ichi Ohkoshi
- Yann Garcia
- Gerard Śliwiński
2020 SCRIPTA MATERIALIA
One of the main barriers hindering applications of Prussian blue metal assemblies is their poor processability, which makes the fabrication of intact thin films very difficult. In this work, a nanocrystalline RbMn[Fe(CN)6]·xH2O film on silicon substrate was obtained for the first time via laser-stimulated deposition and investigated. Temperature-induced phase transition and bistability within broad hysteresis loop (120 K), along with transition temperatures up to 317 K, which is the highest in the RbMnFe series, were observed using variable-temperature Raman spectroscopy. This study thus proposes a reliable deposition approach for preparing a functional magnetic materials that operate at room temperature.
Fundamental properties of solutions to fractional-order Maxwell's equations
- Tomasz Stefański
- Jacek Gulgowski
2020 JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS
In this paper, fundamental properties of solutions to fractional-order (FO) Maxwell's equations are analysed. As a starting point, FO Maxwell's equations are introduced in both time and frequency domains. Then, we introduce and prove the fundamental properties of electromagnetic field in FO electromagnetics, i.e. energy conservation, uniqueness of solutions, and reciprocity. Furthermore, the algorithm of the plane wave simulation is developed and implemented in software, which allows us to demonstrate the general properties of electromagnetic field in the media described by FO models (FOMs). The differences in interpretation of the fundamental theorems of electromagnetics (i.e. Poynting's theorem, the uniqueness theorem and the Lorentz reciprocity theorem) in comparison to integer-order electromagnetics are analysed. It is demonstrated that all the properties of electromagnetic field, related to these fundamental theorems are preserved when time derivatives are generalized towards FO in Maxwell's equations.
Fundamental Schemes to Determine Disjoint Paths for Multiple Failure Scenarios
- Teresa Gomes
- Luisa Jorge
- Rita Girão-Silva
- Jose Yallouz
- Péter Babarczi
- Jacek Rak
2020
Disjoint path routing approaches can be used to cope with multiple failure scenarios. This can be achieved using a set of k (k> 2) link- (or node-) disjoint path pairs (in single-cost and multi-cost networks). Alternatively, if Shared Risk Link Groups (SRLGs) information is available, the calculation of an SRLG-disjoint path pair (or of a set of such paths) can protect a connection against the joint failure of the set of links in any single SRLG. Paths traversing disaster-prone regions should be disjoint, but in safe regions it may be acceptable for the paths to share links or even nodes for a quicker recovery. Auxiliary algorithms for obtaining the shortest path from a source to a destination are also presented in detail, followed by the illustrated description of Bhandari’s and Suurballe’s algorithms for obtaining a pair of paths of minimal total additive cost. These algorithms are instrumental for some of the presented schemes to determine disjoint paths for multiple failure scenarios.
Fundamentals of Communication Networks Resilience to Disasters and Massive Disruptions
- Jacek Rak
- David Hutchison
- Janos Tapolcai
- Rasa Bruzgiene
- Massimo Tornatore
- Carmen Mas-Machuca
- Marija Furdek
- Paul Smith
2020
Communication networks are exposed to a variety of massive failure events following from activities of nature, weather-induced disruptions, technology-implied problems, and malicious human activities. In this chapter, we first highlight the characteristics of these scenarios and discuss example failure events reported during the last three decades. Next, we explain the concept of network resilience and present an overview of major problems and related schemes further addressed in this monograph, concerning (a) measures and models for the analysis and evaluation of disaster-resilient networks, (b) techniques for design and update of disaster-resilient systems, (c) algorithms and schemes for resilient systems, and (d) advanced topics focusing, e.g. on emerging communication technologies.
Fuzzy Control of Waves Generation in a Towing Tank
- Marcin Drzewiecki
- Jarosław Guziński
2020 Pełny tekst ENERGIES
This paper presents the results of research related to the transformation of electrical energy into potential and kinetic energy of waves generated on the water surface. The waves are generated to model the environmental conditions for the needs of the model tests. The model tests are performed on model-scale objects to predict the features of full-scale maritime objects. It is done to improve human safety and the survivability of constructions. Electrical energy is transformed into the energy of the water waves using a wave maker. The wave maker considered is a facility with an electrohydraulic drive and an actuator submerged into the water. The actuator movement results in the waves being mechanically-generated in accordance with the wave maker theory. The study aimed to investigate the advantage of the newly implemented fuzzy-logic controller over the hitherto cascading proportional-integral controllers of the wave maker actuator. The research was focused on experimental investigation of the transformation process outcomes harvested under the fuzzy-logic controller, versus the cascading proportional-integral controllers. The waves were generated and measured in the real towing tank, located in the Maritime Advanced Research Centre (CTO S.A.). The investigation confirmed the advantage of the fuzzy-logic controller. It provides more accurate transformation of energy into the desired form of the water waves of specified parameters—frequency and amplitude—and more flat amplitude-frequency characteristic of the transformation process.
Fuzzy Divisive Hierarchical Clustering of Solvents According to Their Experimentally and Theoretically Predicted Descriptors
- Miroslava Nedyalkova
- Costel Sarbu
- Marek Tobiszewski
- Vasil Simeonov
2020 Pełny tekst Symmetry-Basel
The present study describes a simple procedure to separate into patterns of similarity a large group of solvents, 259 in total, presented by 15 specific descriptors (experimentally found and theoretically predicted physicochemical parameters). Solvent data is usually characterized by its high variability, dierent molecular symmetry, and spatial orientation. Methods of chemometrics can usefully be used to extract and explore accurately the information contained in such data. In this order, advanced fuzzy divisive hierarchical-clustering methods were eciently applied in the present study of a large group of solvents using specific descriptors. The fuzzy divisive hierarchical associative-clustering algorithm provides not only a fuzzy partition of the solvents investigated, but also a fuzzy partition of descriptors considered. In this way, it is possible to identify the most specific descriptors (in terms of higher, smallest, or intermediate values) to each fuzzy partition (group) of solvents. Additionally, the partitioning performed could be interpreted with respect to the molecular symmetry. The chemometric approach used for this goal is fuzzy c-means method being a semi-supervised clustering procedure. The advantage of such a clustering process is the opportunity to achieve separation of the solvents into similarity patterns with a certain degree of membership of each solvent to a certain pattern, as well as to consider possible membership of the same object (solvent) in another cluster. Partitioning based on a hybrid approach of the theoretical molecular descriptors and experimentally obtained ones permits a more straightforward separation into groups of similarity and acceptable interpretation. It was shown that an important link between objects’ groups of similarity and similarity groups of variables is achieved. Ten classes of solvents are interpreted depending on their specific descriptors, as one of the classes includes a single object and could be interpreted as an outlier. Setting the results of this research into broader perspective, it has been shown that the fuzzy clustering approach provides a useful tool for partitioning by the variables related to the main physicochemical properties of the solvents. It gets possible to oer a simple guide for solvents recognition based on theoretically calculated or experimentally found descriptors related to the physicochemical properties of the solvents.
Fuzzy Multi-Regional Fractional PID controller for Pressurized Water nuclear Reactor
- Bartosz Puchalski
- Tomasz Rutkowski
- Kazimierz Duzinkiewicz
2020 Pełny tekst ISA TRANSACTIONS
The paper presents the methodology for the synthesis of a Fuzzy Multi-Regional Fractional Order PID controller (FMR-FOPID) used to control the average thermal power of a PWR nuclear reactor in the load following mode. The controller utilizes a set of FOPID controllers and the fuzzy logic Takagi-Sugeno reasoning system. The proposed methodology is based on two optimization parts. The first part is devoted to finding the optimal parameters of local FOPID controllers and in the second part, the optimal membership functions of the fuzzy reasoning system are designed. During the controller designing and comparison phase, the two validated nodal models of a nuclear reactor are used, simplified model and extended model respectively. The proposed approach has been verified by computer simulations that confirm its effectiveness.
GaN Nanowire Array for Charge Transfer in Hybrid GaN/P3HT:PC71BM Photovoltaic Heterostructure Fabricated on Silicon
- Giorgi Tchutchulashvili
- Sergij Chusnutdinow
- Wojciech Mech
- Krzysztof P. Korona
- Anna Reszka
- Marta Sobanska
- Zbigniew R. Zytkiewicz
- Wojciech Sadowski
2020 Pełny tekst Materials
Abstract: We demonstrate that a GaN nanowire array can be used for efficient charge transfer between the organic photovoltaic layer and silicon in a Si/GaN/P3HT:PC71BM inverted hybrid heterostructure. The band alignment of such a material combination is favorable to facilitate exciton dissociation, carrier separation and electron transport into Si. The ordered nature of the GaN array helps to mitigate the intrinsic performance limitations of the organic active layer. The dependence of photovoltaic performance enhancement on the morphology of the nanostructure with nanowire diameters 30, 50, 60, 100 and 150 nm was studied in detail. The short circuit current was enhanced by a factor of 4.25, while an open circuit voltage increase by 0.32 volts was achieved compared to similar planar layers.