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Repozytorium publikacji
Politechniki Gdańskiej

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  • Komu i jak z sukcesem przekazać pałeczkę? Transfer przedsiębiorstw w polskim sektorze MSP
    • Marzena Grzesiak
    • Piotr Kasprzak
    • Magdalena Olczyk
    • Anita Richert-Kaźmierska
    2020 Pełny tekst

    Transfer biznesu jest fazą w cyklu życia biznesu, przedsiębiorstwa czy właściciela. Nie dla każdej firmy przeniesienie kończy się sukcesem. Część firm „umiera”, a zastępują je nowe, lepiej dopasowane do potrzeb gospodarki. Transfer przedsiębiorstwa trudniejszy jest w firmach mniejszych, gdzie właściciel odgrywa dominującą rolę. W monografii omówione zostaną wybrane zagadnienia związane z procesem przekazania biznesu w małych i średnich firmach, ze zwróceniem szczególnej uwagi na sukcesję oraz uwypuklone zostały działania umożliwiające sprawne jej przeprowadzenie. Celem monografii jest przedstawienie jak najszerszego spektrum problemu sukcesji w małych i średnich przedsiębiorstwach, zarówno od strony teoretycznej jak i ukazania aspektów praktycznych przekazania małej i średniej firmy. Monografia skierowana jest zarówno do przedsiębiorców/właścicieli małych i średnich firm, praktyków zajmujących się sukcesją, organizacji wspierających działalność przedsiębiorstw jak i do studentów oraz doktorantów kierunków ekonomicznych (potencjalnych sukcesorów, menedżerów firm). W rozdziale pierwszym przeprowadzono teoretyczną próbę przeglądu definicji transferu biznesu oraz skupiono się na procesie sukcesji w małym i średnim przedsiębiorstwie. W rozdziale drugim monografii omówiono najczęściej wybierane przez przedsiębiorstwa sektora MSP w Polsce formy przekazania firmy przez dotychczasowych właścicieli: sukcesję, wprowadzenie zewnętrznego zarządu oraz sprzedaż. Rozdział trzeci monografii poświęcony został nowym rozwiązaniom zawartym w ustawie, dotyczącym ustanowienia zarządu sukcesyjnego. W kolejnej części monografii opisano istotne, praktyczne aspekty związane z wykorzystaniem mechanizmów wprowadzonych ustawą o zarządzie sukcesyjnym w listopadzie 2018 roku. Dokonano analizy najważniejszych rozwiązań odpowiadając m.in. na pytania „czym jest zarząd sukcesyjny?”; „jakie czynności może wykonywać powołany zarządca sukcesyjny?”; „jakie są najważniejsze skutki podatkowe związane z wprowadzeniem w przedsiębiorstwie zarządu sukcesyjnego?”; a także „dlaczego warto rozważyć wprowadzenie zarządcy sukcesyjnego w firmie rodzinnej?”. Natomiast w rozdziale piątym zwrócono uwagę na możliwość uzyskania wsparcia o różnym charakterze od organizacji czy instytucji, wspomagające poszczególne etapy procesu transferu przedsiębiorstw (szczególnie etap planowania sukcesji), jak również przedstawiono dostępne narzędzia ułatwiające znalezienie potencjalnego sukcesora.

  • KONCEPCJA DIAGNOZOWANIA GNIAZD ZAWORÓW CYLINDROWYCH SILNIKÓW OKRĘTOWYCH W EKSPLOATACJI
    • Zbigniew Korczewski
    2020 Pełny tekst Journal of Polish CIMEEAC

    W artykule przybliżono fizykę uszkodzeń eksploatacyjnych zaworów cylindrowych silników okrętowych oraz technologię ich naprawy. Zaprezentowano system diagnozujący tego typu silników, który znajduje się na wyposażeniu bazy laboratoryjnej Katedry Siłowni Morskich i Lądowych WOiO PG. Umożliwia on przeprowadzenie kompleksowej oceny stanu technicznego przestrzeni roboczych silników zabudowanych w siłowni okrętowej w bieżącej eksploatacji. Zaproponowano schemat organizacji badań zaworów cylindrowych z wykorzystaniem posiadanego systemu diagnozującego dla potrzeb dokonania oceny skuteczności zaadaptowanej technologii naprawy gniazd zaworowych.

  • Koncepcja "Myślenia Mitycznego" Ernsta Cassirera
    • Andrzej Karalus
    • Przemysław Parszutowicz
    2020

    Artykuł krótko rekapituluje teorię myślenia mitycznego Ernsta Cassirera, osadzając jego teorię na tle tradycji idealizmu niemieckiego, neokantyzmu i filozofii symbolicznej.

  • Koncepcja połączenia kolejowego Morskiego Portu Gdynia S.A. z Kolejową Obwodnicą Trójmiasta
    • Eugeniusz Dembicki
    • Eligiusz Mieloszyk
    • Sławomir Grulkowski
    • Anita Milewska
    • Kamila Szwaczkiewicz
    2020 Pełny tekst Inżynieria Morska i Geotechnika

    Zapotrzebowanie na połączenie rozwijającego się Morskiego Portu Gdynia z Kolejową Obwodnicą Trójmiasta. Utworzenie tak zwanych „długich pociągów”. Wpływ katastrof kolejowych na warunki gruntowe i środowisko. Potrzeba modernizacji linii kolejowych. Kolejowa Obwodnica Trójmiasta jako alternatywa dla przejazdu pociągów przez obszar Aglomeracji Trójmiejskiej.

  • Konkurs o Pomorską Nagrodę Jakości w czasach Gospodarki Opartej na Wiedzy
    • Anna Wendt
    2020

    Celem autorki jest analiza wpływu aspektu zarządzania wiedzą u uczestników XXII edycji Konkursu o Pomorską Nagrodę Jakości na wynik oraz uzyskanie wyróżnienia. Konkurs składa się z kilku etapów, m.in. samooceny oraz weryfikacji w siedzibie uczestnika przeprowadzonej przez ekspertów Polskiego Rejestru Statków. Po udziale w konkursie organizacja biorąca w nim udział, poza aspektami marketingowymi uzyskuje informacje zwrotną w postaci raportu w którym zawarta jest dokładna punktacja oraz mocne strony organizacji oraz tzw. obszary do doskonalenia. Celem niniejszej pracy jest analiza mocnych stron organizacji biorących udział w konkursie oraz określenie ile z nich dotyczy tematu zarządzania wiedzą i jakie ma to przełożenie na wyniki konkursu oraz proces ciągłego doskonalenia się.

  • Konstrukcje z gruntu zbrojonego geosyntetykami odciążające przyczółki - Analiza temperatur
    • Angelika Duszyńska
    • Krzysztof Żółtowski
    • Przemysław Kalitowski
    2020 Mosty

    W artykule podjęto, bardzo istotny z punktu widzenia bezpieczeństwa i trwałości konstrukcji, temat zachowania się w czasie przyczółków mostowych, które zaprojektowano z wykorzystaniem konstrukcji odciążających z gruntu zbrojonego geosyntetykami. Na dwóch przykładach przeanalizowano zmienność temperatur wewnątrz bloku z gruntu zbrojonego. Temperatura w otoczeniu geozbrojenia syntetycznego może mieć istotny wpływ na jego trwałość.

  • Konwersja komunalnych osadów ściekowych w nawóz organiczny w systemach trzcinowych
    • Katarzyna Kołecka
    • Hanna Obarska-Pempkowiak
    2020 Pełny tekst

    Dla małych i średnich oczyszczalni ścieków ciekawą alternatywą może być metoda wykorzystująca systemy trzcinowe do jednoczesnego odwadniania i stabilizacji osadów. Metoda ta jest powszechnie znana i wykorzystywana w wielu krajach europejskich, np. we Francji, w Dani, a także w Szwecji, Norwegii, Hiszpanii i we Włoszech. W Polsce, w skali technicznej, systemy trzcinowe pracują m.in. na terenie konwencjonalnej oczyszczalni ścieków w Gniewinie k. Wejherowa oraz w Zambrowie w województwie podlaskim (Kołecka i in., 2018). Systemy trzcinowe eliminują główne problemy, które występują podczas mechanicznego odwadniania. Przede wszystkim nie wymagają drogich urządzeń do odwadniania. Eliminują również robociznę związaną z procesem mechanicznego odwadniania oraz konieczność stosowania drogich polielektrolitów. Istotnie też zmniejszają uciążliwości związane z magazynowaniem odwodnionych osadów, ich zagniwaniem oraz koniecznością stosowania wielokrotnie w ciągu roku. Systemy trzcinowe są przede wszystkim łatwe w obsłudze oraz charakteryzują się niskimi kosztami eksploatacyjnymi. Metoda ta daje możliwość dostosowania jej do lokalnych warunków terenowych, a naturalne walory umożliwiają łatwe wkomponowanie w istniejący krajobraz. Procesy odwadniania i stabilizacji w systemach trzcinowych zachodzą podobnie jak w warunkach naturalnych, a działanie metody związane jest z symulacją procesów zachodzących w ekosystemach bagiennych.

  • Koopetycja w trzech odsłonach
    • Jan Kreft
    • Krzysztof Leja
    2020

    Książka ta, poświęcona dynamicznie rozwijającemu kierunkowi badań nad osobliwym zjawiskiem, jakim jest koopetycja, czyli jednoczesne występowanie konkurowania i współ¬pracy, oferuje wyprawę w nieoczywiste rejony zarządzania, w których wiedza ekspercka w ramach nurtu ekonomicznego spotyka się z poglądami humanistycznymi z ich uniwersa¬lizmami ludzkich niedoskonałości, uparcie objawiających się w środowisku nieustępliwie dążącym do kwantyfikacji tego, co wydaje się niepoliczalne, a co ma znakomity wpływ nie tylko na każdy etap zarządzania strategicznego, ale też na jego skutki. Proponujemy przerzucenie pomostu łączącego wiedzę płynącą z zarządzania interpre¬towanego w ramach analiz ilościowych i dorobek nauk, w których równoprawne miejsce zajmują humanistyczne „niepoliczalności” i „nieoczywistości”. W istocie więc proponujemy powrót do źródeł zarządzania w nurcie humanistycznym wytyczanym przez Maxa Webera i Eltona Mayo. W kontekście badań nad koopetycją dostrzegamy, podkreślając ich znaczenie, czynniki zakłócające łańcuch zdarzeń/przypadków, wyróżniając, a wręcz wynosząc na pierwszy plan wolną wolę człowieka w zarządzaniu. Jako pola swych obserwacji wybraliśmy dwa z pozoru odległe środowiska: szkolnictwo wyższe i media cyfrowe. Nieprzypadkowo – oba bowiem wymykają się łatwemu narzuceniu ram formalnych i w obu – to ich cecha nadrzędna – fundamentalną rolę pełnią liderzy for¬malni i nieformalni; to ich cechy i ich wpływ są przedmiotem szczególnego zainteresowania w tej publikacji. Oba środowiska cechują się tym, że podstawowe znaczenie ma w nich to, co przyjęło się określać zarządzaniem wiedzą. Obydwa są ekosystemami prymatu tworzenia wartości niematerialnych w organizacjach i oba cechuje ponadprzeciętny brak determinizmu. Skupiając się na tych kwestiach, proponujemy określony porządek rozważań. W odsłonie pierwszej prezentujemy przegląd literatury światowej na temat koopetycji w zarządzaniu strategicznym organizacjami, bez względu na ich status prawny oraz zakres działalności. W odsłonie drugiej odnosimy koncepcję koopetycji do mediów, zastanawiając się nad tym, czy jest to recepta na stające przed nimi wyzwania strategiczne. Odsłona trzecia poświęcona jest rozważaniom nad koopetycją w instytucjach akademickich.

  • Kultura jakości i czynniki ją kształtujące w szkołach wyższych
    • Piotr Grudowski
    • Małgorzata Wiśniewska
    2020 Problemy Jakości

    W artykule przedstawiono rozważania dotyczące kultury jakości w instytucjach szkolnictwa wyższego. Szczególną uwagę zwrócono na czynniki, które wspierają rozwój kultury jakości w uczelniach oraz na te, które stanowią bariery jej pozytywnego rozwoju. Zagadnienie to zostało zaprezentowane na tle różnych wyników badań dotyczących kultury jakości jako specyficznej subkultury organizacyjnej.

  • La storia economica in Italia e in Germania. Fuori o dentro il dibattito pubblico?
    • Luciano Segreto
    2020

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  • Laboratorium Zanurzonej Wizualizacji Przestrzennej
    • Jacek Lebiedź
    2020

    W opracowaniu opisano Laboratorium Zanurzonej Wizualizacji Przestrzennej, jego wyposażenie, potencjał i zastosowania.

  • Landscape perception and the teaching of it in Poland
    • Anna Górka
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    A preliminary assessment of the state of knowledge of landscape perception is contained in this article. A survey was carried out of students of architecture and urban planning during the rural design course in the academic year 2017/2018. The pilot project involved the initial establishment of categories of the countryside image. It was assumed that the results represented students’ knowledge of the landscape characteristics and indirectly reflected the level of social knowledge. The results of the study revealed general spatial incompetence and the causes of it. Education in landscape perception is a support for local societies in land management and landscape protection. The Council of Europe in the European Landscape Convention from 2000 advised EU countries to engage the population in spatial and ecological policy. In Poland, the rapid degradation of rural landscapes means systemic remedies would be particularly desirable. Outlined in this article are the principles for change in social education.

  • Laser Dissimilar Welding of AISI 430F and AISI 304 Stainless Steels
    • Krzysztof Pańcikiewicz
    • Aleksandra Świerczyńska
    • Paulina Hućko
    • Marek Tumidajewicz
    2020 Pełny tekst Materials

    A dissimilar autogenous laser welded joint of AISI 430F (X12CrMoS17) martensitic stainless steel and AISI 304 (X5CrNi18-10) austenitic stainless steel was manufactured. The welded joint was examined by non-destructive visual testing and destructive testing by macro- and microscopic examination and hardness measurements. With reference to the ISO 13919-1 standard the welded joint was characterized by C level, due to the gas pores detected. Microscopic observations of AISI 430F steel revealed a mixture of ferrite and carbides with many type II sulfide inclusions. Detailed analysis showed that they were Cr-rich manganese sulfides. AISI 304 steel was characterized by the expected austenitic microstructure with banded δ-ferrite. Martensitic microstructure with fine, globular sulfide inclusions was observed in the weld metal. The hardness in the heat-affected zone was increased in the martensitic steel in relation to the base metal and decreased in the austenitic steel. The hardness range in the weld metal, caused by chemical inhomogeneity, was 184–416 HV0.3.

  • Laser induced formation of copper species over TiO2 nanotubes towards enhanced water splitting performance
    • Katarzyna Grochowska
    • Zuzanna Molenda
    • Jakub Karczewski
    • Julien Bachmann
    • Kazimierz Darowicki
    • Jacek Ryl
    • Katarzyna Siuzdak
    2020 Pełny tekst INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    We proposed fast and scalable route where the ordered TiO2 nanotubes coated with thin copper layers were annealed by the laser beam of 355 nm wavelength at different fluencies in the range of 15–120 mJ/cm2. As a result, copper species are integrated with the titania substrate and the formed material exhibits unique optical absorption bands in the visible range. Moreover, X-ray photoelectron spectroscopy analysis reveals the formation of Cu2O while the 4+ oxidation state of titanium is preserved. According to the electrochemical results, the material treated by laser exhibits outstanding photoelectrochemical activity comparing to the pristine titania or the one only covered by the thin copper film. In particular, when the fluence of 60 mJ/cm2 was used for the modification of the titania decorated with Cu film, the current density recorded in KOH electrolyte reaches nearly 4.5 mA/cm2 at +2.0 V vs. Ag/AgCl/0.1 M KCl upon visible light.

  • Laser-assisted modification of titanium dioxide nanotubes in a tilted mode as surface modification and patterning strategy
    • Jakub Wawrzyniak
    • Jakub Karczewski
    • Piotr Kupracz
    • Katarzyna Grochowska
    • Karol Załęski
    • Oleksandr Pshyk
    • Emerson Coy
    • Michał Bartmański
    • Marek Szkodo
    • Katarzyna Siuzdak
    2020 Pełny tekst APPLIED SURFACE SCIENCE

    Electrochemical anodization is regarded as a facile and easily scalable fabrication method of titania nanotubes (TiO2NTs). However, due to the extended duration of calcination and further modifications, much faster alternatives are highly required. As a response to growing interest in laser modification of nanotube arrays, a comprehensive investigation of pulsed-laser irradiation and its effect onto TiO2NT properties has been carried out. The impact of irradiation onto the surface being placed at different angles in respect to the laser beam was studied and evaluated. The usage of the motorized table enables formation of laser-treated traces over the selected area. SEM and TEM analysis provides insight into morphological changes and shows partial melting of nanotubes surface, which is accompanied by the decrease of internal TiO2 tube diameter just below the melted region. Although structural and optical analysis consisting of Raman, photoluminescence and UV–Vis data indicate that presented method does not result in complete material crystallization, it promotes creation of advantageous localized states within TiO2 bandgap that may play a crucial role in charge separation. Moreover, impressive improvements to the mechanical properties resulting from the laser-modification are presented.

  • Laser-Assisted Synthesis and Oxygen Generation of Nickel Nanoparticles
    • Jakub Wawrzyniak
    • Jakub Karczewski
    • Jacek Ryl
    • Katarzyna Grochowska
    • Katarzyna Siuzdak
    2020 Pełny tekst Materials

    Nowadays, more than ever, environmental awareness is being taken into account when it comes to the design of novel materials. Herein, the pathway to the creation of a colloid of spherical, almost purely metallic nickel nanoparticles (NPs) through pulsed laser ablation in ethanol is presented. A complex description of the colloid is provided through UV-vis spectroscopy and dynamic light scattering analysis, ensuring insight into laser-induced nanoparticle homogenization and size-control of the NPs. The transmission electron spectroscopy revealed spherical nanoparticles with a narrow size distribution, whereas the energy-dispersive X-ray spectroscopy accompanied by the X-ray photoelectron spectroscopy revealed their metallic nature. Furthermore, an example of the application of the colloidal nanoparticles is presented, where a quick, five-min ultrasound modification results in over an order of magnitude higher current densities in the titania-based electrode for the oxygen evolution reaction.

  • Latest Achievements in Concrete Structures Three-Dimensional Printing
    • Patryk Ziółkowski
    • Maciej Niedostatkiewicz
    2020

    We can hear about three-dimensional printed concrete structures for several years, up to date solutions in this technology allow entire printing settlements of tiny concrete houses. Due to technical limitations, these houses are still small and not very durable, but undoubtedly, this technology is developing. Home printed in three-dimensional technology can be an alternative to modular container buildings implemented in areas affected by natural disasters and as a solution for low-cost small residential houses. We believe that in a few years it will reach its full potential by entering a constructions mainstream. Printing concrete structures have many advantages over casual concrete casting. First of all, it is the speed of the construction process, three-dimensional printed houses can me build quicker, and relatively low printing costs. Printing concrete structures is not labour-intensive and is more environmentally friendly due to lower consumption of energy and reduction of construction waste to zero. In this paper, we will analyse the current state of the art in concrete structures three-dimensional printing technology, we will describe the dominant and developing trends, and we will consider in what direction this technology may improve in the future. The most common problems related to the implementation of construction nodes of small residential houses in three-dimensional technology will also be indicated. In addition, methods will be proposed to increase the spatial stiffness of printed houses, taking into account the optimisation of costs in terms of technology and time of completion.

  • Learning from Mistakes. A Study on Maturity and Adaptability to Change
    • Wioleta Kucharska
    • Denise A. D. Bedford
    2020 Pełny tekst

    Learning culture matters; company culture must support continuous improvement. Organizational learning is a process of identifying and modifying mistakes that result from interactions between co-workers. The article aims to explore the learning power via errors, using the level of organizational maturity as a moderator. Companies need to know how organizational maturity may moderate the adaptability to change via the acceptance of their mistakes. Based on 380 samples gathered from November to December 2019 among Polish employees working in knowledge-driven organizations across various industries, and analyzing the data using PROCESS software, the authors established that employees working in young organizations adapt to changes better than those who work in mature companies. On the other hand, the acceptance of mistakes by mature organizations significantly improves their adaptability to change. The study shows that mature organizations achieve better change adaptability than young organizations when accepting mistakes. The conclusion is that mature organizations may adapt to changes only if they accept errors (learn from their errors). Concerning young organizations' mistakes, their effect on adaptability to change is not significant.

  • Light Symposium. Connecting health research with lighting practice
    • Karolina Zielińska-Dąbkowska
    2020 Pełny tekst ARC Lighting In Architecture

    Thanks to state-of-the-art medical and environmental research, our current understanding about the impact of light and lighting is improving at a rapid rate. While the evolution of lighting technologies offers promising design possibilities, it also poses new challenges to planners and the general public. This is further complicated by the fact that today’s modern indoor lifestyle means we can be completely disconnected from nature and natural light. Instead, we live under artificial skies in man-made environments. To answer the need for cross-disciplinary talks and in order to bridge the knowledge gaps in the field of architectural lighting design, in 2007, the concept of a Light Symposium emerged at the Professional Lighting Designers Convention (PLDC) in London. Michael F. Rohde, a German lighting designer and professor at the Hochschule Wismar (HSW) in Wismar, was inspired to create an interdisciplinary event where light and health could be holistically addressed and connected with research and practice.

  • Light-improved glucose sensing on ordered Au-Ti heterostructure
    • Katarzyna Siuzdak
    • Dirk Döhler
    • Julien Bachmann
    • Jakub Karczewski
    • Katarzyna Grochowska
    2020 OPTIK

    Non-enzymatic electrochemical platforms sensitive towards glucose presence have attracted a worldwide attention during last decades. We report on influence of solar light onto response of gold-titanium heterostructures prepared via controllable approach. The material based on Au nanoparticles orderly distributed over the structured titanium foil was obtained by electrochemical anodization followed by chemical etching, magnetron sputtering of gold and finally thermal treatment in the continuous regime. It is proven that the applied synthesis route leads to the enhanced visible light absorption boosting material photoactivity. Fabricated electrode immersed in the glucose containing solution and exposed to the solar light exhibits superior increase of oxidation current comparing to pristine substrate before thermal annealing. Photosensor is characterized by broad linear response up to 40 mM of glucose, limit of detection of 0.2 and 0.1 mM and sensitivity of 3.08 and 0.92 μA/cm2 in NaOH and PBS, respectively. It is concluded that the electrode exhibits enhanced performance taking advantage from plasmon resonance effect and the presence of thin titania passive film. Moreover, obtained material is stable under prolonged illumination and was verified in the presence of blood serum sample. Overall, presented results suggest that the impact of solar light should be taken into account during works on sensing devices.

  • Light-Powered Starter for Micro-Power Boost DC–DC Converter for CMOS Image Sensors
    • Grzegorz Blakiewicz
    • Jacek Jakusz
    • Miron Kłosowski
    • Waldemar Jendernalik
    • Stanisław Szczepański
    2020 Pełny tekst CIRCUITS SYSTEMS AND SIGNAL PROCESSING

    The design of a starter for a low-voltage, micro-power boost DC–DC converter intended for powering CMOS image sensors is presented. A unique feature of the starter is extremely low current, below 1 nA, supplying its control circuit. Therefore, a high-voltage (1.3 V) configuration of series-connected photovoltaic diodes available in a standard CMOS process or a small external LED working in photovoltaic mode can be used as an auxiliary supply for the control circuit. With this auxiliary supply, the starter can generate a starting voltage from 1 to 2.7 V using 50–200 mV supply voltage. The starter was verified by simulations and measurements of a prototype chip fabricated in a standard 180-nm CMOS technology. The results of simulations and tests showed correct operation of the starter in the temperature from 0 to 50 °C and under process parameters variation.

  • Limited selectivity of amperometric gas sensors operating in multicomponent gas mixtures and methods of selectivity improvement
    • Marta Dmitrzak
    • Piotr Jasiński
    • Grzegorz Jasiński
    2020 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences

    In recent years, smog and poor air quality have became a growing environmental problem. There is a need to continuously monitor the quality of the air. The lack of selectivity is one of the most important problems limiting the use of gas sensors for this purpose. In this study, the selectivity of six amperometric gas sensors is investigated. First, the sensors were calibrated in order to find a correlation between the concentration level and sensor output. Afterwards, the responses of each sensor to single or multicomponent gas mixtures with concentrations from 50 ppb to 1 ppm were measured. The sensors were studied under controlled conditions, a constant gas flow rate of 100 mL/min and 50 % relative humidity. Single Gas Sensor Response Interpretation, Multiple Linear Regression, and Artificial Neural Network algorithms were used to predict the concentrations of SO2 and NO2. The main goal was to study different interactions between sensors and gases in multicomponent gas mixtures and show that it is insufficient to calibrate sensors in only a single gas.

  • Limiting distribution of the three-state semi-Markov model of technical state transitions of ship power plant machines and its applicability in operational decision-making.
    • Jerzy Girtler
    2020 Pełny tekst Polish Maritime Research

    The article presents the three-state semi-Markov model of the process {W(t): t 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application of this model to examine models of real state transitions of ship power plant machines. Empirical data concerning ME were used for calculating limiting probabilities for the process {W(t): t 0}. The applicability of these probabilities in decision making with the assistance of the Bayesian statistical theory is demonstrated. The probabilities were calculated using a procedure included in the computational software MATHEMATICA, taking into consideration the fact that the random variables representing state transition times of the process {W(t): t 0} have gamma distributions. The usefulness of the Bayesian statistical theory in operational decision-making concerning ship power plants is shown using a decision dendrite which maps ME states and consequences of particular decisions, thus making it possible to choose between the following two decisions: d1 – first perform a relevant preventive service of the engine to restore its state and then perform the commissioned task within the time limit determined by the customer, and d2 – omit the preventive service and start performing the commissioned task.

  • L’indistricabile intreccio. Imprese, imprenditori e regime fascista. (An Inextricable Intertwining. Companies, Entrepreneurs, and the Fascist Regime)
    • Luciano Segreto
    2020 Studi Storici

    The papers of this section analyse the relationships between the economic and business community and the fascist regime. Their aim is to refresh the interpretations that were established in the 1960s-1970s and remained undisputed in the decades thereafter, becoming a sort of mantra among Italian contemporary historians. The article presents the most relevant contributions of that historiographical season, explaining the reasons for a new approach and a new interpretation on the strength of the numerous public, business, and private archives that have become available over the past 20-30 years, extensive use of which has been made by the papers included in this section

  • Linezolid-resistant Enterococcus faecium strains isolated from one hospital in Poland –commensals or hospital-adapted pathogens?
    • Beata Krawczyk
    • Magdalena Wysocka
    • Roman Kotłowski
    • Marek Bronk
    • Michał Michalik
    • Alfred Samet
    2020 Pełny tekst PLOS ONE

    One of the most pressing problems of enterococci infections is occurring resistance to linezolid, which is an antibiotic used in the treatment of infections caused by vancomycin-resistant strains (VRE). The main objective of our research was to investigate the relationship of 19 linezolid-resistant E. faecium isolates from 18 patients hospitalized at Clinical Hospital in Gdansk (Poland). One of the LZDREF was isolated in 2003 (K2003), and another 18 were collected from 2013 to 2017. Genotyping with PCR MP method indicated 14 main unrelated genetic profiles and no association with K2003 strain. Two isolates with the same genotype and genetically closely related two sub-types (2 isolates for each sub-type) were hospital-derived colonizations of patients. The other unrelated genotypes were discussed in the context of colonization, nosocomial infections, and commensal origin, taking into account prior exposure to linezolid. We determined the presence of a point mutation G2576T in six loci of 23S rDNA. There was also a significant correlation (p<0.0015) between the presence of MIC>32 value and the presence of G2576T point mutation on the sixth rrn. We also detected 5 virulence genes for all isolates: gelE, cylA, asa1, hyl, esp. Correlation (p≤0.0001) was observed between the presence of gelE gene encoding gelatinase and two other genes: cylA and asa1 encoding cytolysin and collagen binding protein responsible for aggregation of bacterial cells, respectively. Significant correlation was also observed between asa1 and cfr genes encoding 23S rRNA rybonuclease responsible for resistance to PhLOPSA antibiotics (p = 0.0004). The multidimensional analysis has also shown the correlation between cfr gene and GI-tract (p = 0, 0491), which suggests horizontal gene transfer inside the gut microbiota and the risk of colonization with linezolid-resistant strains without previously being treated with the antibiotic. The patient could have been colonized with LZDRVREF strains which in the absence of competitive microbiota quickly settle in ecological niches favourable for them and pose a risk for the patient. 

  • Lipidomika – strategie analityczne i zastosowania
    • Weronika Hewelt-Belka
    • Agata Kot-Wasik
    2020

    Bioanalityka, to interdyscyplinarna dziedzina wiedzy, która stanowi szybko rozwijający się obecnie dział chemii analitycznej. Bioanaliza zaczyna odgrywać kluczową rolę w szybko rozwijających się dziedzinach współczesnej bionauki w ramach genomiki, proteomiki, metabolomiki, lipidomiki i innych. Umiejętność doboru odpowiednich metod i narzędzi, w zależności od rodzaju podejmowanego problemu, jest niezwykle ważne i często decyduje o powodzeniu zarówno kolejnych etapów jak i całości badań. Duże zainteresowanie bioanalityką, w tym kształcenie na poziomie przedmiotów podstawowych i specjalnościowych, jak również funkcjonowanie specjalności „Bioanalityka” na wielu uczelniach, potrzeby laboratoriów klinicznych czy medycyny sądowej, czy kontroli jakości produktów spożywczych i żywności, skłoniły redaktorów naukowych do przygotowania niniejszej książki. Przedstawione w niej zagadnienia będą przydatne studentom i pracownikom naukowym, pracownikom laboratoriów badawczych również z pokrewnych dziedzin. Książka ta jest opracowaniem zbiorowym, w którym znakomici specjaliści z różnych ośrodków naukowych i badawczych w Polsce przedstawili – potencjał, aplikacje kliniczne i środowiskowe oraz perspektywy dalszego rozwoju bioanalityki.

  • Lipidy szkodliwe dla zdrowia
    • Izabela Sinkiewicz
    2020

    Lipidy są niezbędne w diecie człowieka.Są one źródłem energii, niezbędnych, nienasyconych kwasów tłuszczowych i cholesterolu. Jednakże przekroczenie ich spożycia w stosunku do zapotrzebowania, stanowi zagrożenie dla zdrowia.Znajomość i przestrzegania prawidłowych racji lipidów i ich rodzaju w żywieniu powinno zapewnić konsumentom profilaktykę metabolicznych chorób układu krążenia oraz zapobiec nowotworom i otyłości

  • Liquefaction of alder wood as the source of renewable and sustainable polyols for preparation of polyurethane resins
    • Kamila Gosz
    • Daria Kowalkowska-Zedler
    • Józef Haponiuk
    • Łukasz Piszczyk
    2020 WOOD SCIENCE AND TECHNOLOGY

    Liquefaction of wood-based biomass gives different polyol properties depending on the reagents used. In this article, alder wood sawdust was liquefied with glycerol and poly(ethylene glycol) solvents. Liquefaction reactions were carried out at temperatures of 120, 150 and 170 °C. The obtained bio-polyols were analyzed in order to establish the process efficiency, hydroxyl number, acid value, viscosity and structural characteristics using Fourier transform infrared (FTIR), carbon (13C) and proton (1H) NMR analyses. The results indicate that the optimal conditions for the liquefaction process are at 150 °C for 6 h. The results of the FTIR spectra analysis and the hydroxyl number in the range of 214–687 mg KOH/g showed that the obtained bio-polyols are a potential substitute for petrochemical polyols commonly used for the synthesis of polyurethane polymers. Polyurethane resins containing 90 wt% of bio-polyol were obtained by a one-step method using a hydraulic press. The material was pressed for 15 min (5 MPa) at 100 °C with an NCO/OH ratio in the range of 0.9–1.2. Dynamic mechanical thermal analysis (DMA) showed high cross-linking density and modulus of elasticity in a wide range of 62–1362 MPa.

  • Literature review of user needs, toward user requirements
    • Claudia Naves David Amorim
    • David Geisler-Moroder,
    • Thorbjörn Laike
    • Justyna Martyniuk-Pęczek
    • Barbara Szybińska-Matusiak
    • Wilfried Pohl
    • Natalia Sokół
    2020

    This report has been developed in the frame of the IEA SHC Task 61 Subtask A “User requirements”. The main objective was to rethink and reformulate user requirements to lighting (daylighting and electric lighting) in public buildings on the basis of a thorough literature study. The work is a joint effort of a number of scientists and represents collective knowledge in this topic. The concept of Lighting quality is the one, among many lighting concepts, which expresses the user perspective best. Lighting quality is the important goal of lighting designers and planners; however, it is difficult to define and to measure. The following definition of lighting quality has been used for many years: Lighting quality is a concept that allows excellent vision while providing high comfort. (Kruisselbrink, Dangol and Rosemann) (2018) In this recent paper, the authors try to find measures that could be directly used for describing the lighting quality: quantity, glare, spectral power distribution, distribution of light, directionality and dynamics. The overview also shows that the luminance distribution is a suitable way for at least getting useful information of the lighting quality. If spectral distribution is added to these measurements an even better description of the lighting quality is obtained. The above-mentioned definition of lighting quality focuses at humans, but it does not take into consideration aspects of light that have indirect and profound impact on human health and well-being. Those are the non-image forming aspects of light and some psychological aspects. In this report those additional aspects are included and structured in chapters as follows: 1. Perception of light 2. Visual Comfort 3. Psychological aspects of lighting (view out, perceived quality of space, privacy, etc.) 4. Non-image forming aspects of light (ipRGCs action spectrum, hormones, etc.) By using these four different basic aspects we have the possibility to define several criteria for lighting quality, both image-forming and non-image forming. We have also the possibility to compare between qualities of electric lighting and daylighting. During the last twenty years the knowledge about light and lighting has developed and at the same time the technological development has been immense. Today we are able to get much more electrical lighting with less energy than ever before, but is the light of good quality? We need to develop evaluation methods.

  • LNG TANK IN ŚWINOUJŚCIE: NONLINEAR ANALYSIS OF THE TANK DOME ELEMENTS BEHAVIOUR
    • Bartosz Sobczyk
    2020 Pełny tekst Polish Maritime Research

    In this paper, the dome of a tank in the Świnoujście LNG terminal is analysed. Some of the rafter ribs at the connection with hangers were not mounted during construction of the tank dome. Therefore, it has become necessary to estimate its response, which has been done with the aid of some computational models of the dome, that have been created in the finite element method environment. Different local models are studied, aiming to recreate possible outermost conditions of the tank dome response, i.e. with or without composite action between steel and concrete parts of the tank dome. Static calculations with material and geometric nonlinearities are carried out on the computational models, enabling the creation of a load capacity envelope of the rafter with or without ribs. The obtained results are then used to decide if repair works need to be done and whether the missing ribs should be welded.

  • Local and global response of sandwich beams made of GFRP facings and PET foam core in three point bending test
    • Łukasz Pyrzowski
    • Bartosz Sobczyk
    2020 Pełny tekst COMPOSITE STRUCTURES

    In the paper behaviour of laminated sandwich beams (FRP face sheet – PET foam core – FRP face sheet) subjected to three point bending is studied. The paper aim is to find practical descriptions enabling effective and accurate estimation of the elastic response, damage and failure of the beams, basing on experiments and static calculations. Therefore a number of tests are described, that were done on laminated coupons and foam specimens in order to choose appropriate material models and find their constants. Experimental results of three-point bending tests of sandwich beams with three types of PET cores are analysed to evaluate the chosen material laws. The beam responses are predicted in numerical static simulations. The equations of problem are solved by means of finite element method (FEM). In the end the experimental and FEM results are compared. They are similar in terms of both their quantity and quality.

  • Local buckling of composite channel columns
    • Czesław Szymczak
    • Marcin Kujawa
    2020 Pełny tekst CONTINUUM MECHANICS AND THERMODYNAMICS

    The investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic material modelling are performed: the homogenization with the aid of theory of mixture and periodicity cell or homogenization upon the Voigt–Reuss hypothesis. The fundamental differential equation of local buckling is derived with the aid of the stationary total potential energy principle. The critical buckling stress corresponding to a number of buckling half-waves is assumed to be a minimum eigenvalue of the equation. Some numerical examples dealing with columns are given here. The analytical results are compared with the finite element stability analysis carried out by means of ABAQUS software. The paper is focused on a close analytical solution of the critical buckling stress and the associated buckling mode while the web–flange cooperation is assumed.

  • Lokalizacja terminala ruchomego w korytarzu przy użyciu kabli promieniujących
    • Olga Błaszkiewicz
    • Jarosław Sadowski
    • Jacek Stefański
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W referacie przedstawiono wyniki testów możliwości określania położenia terminala ruchomego wzdłuż korytarza na podstawie propagacji sygnałów w kablach promieniujących w dwóch kierunkach. Opisane zostało stanowisko pomiarowe oraz wyniki uzyskane przy różnych sposobach wytwarzania sygnałów pomiarowych w instalacji jedno- i dwuprzewodowej.

  • Long Distance Geographically Distributed InfiniBand Based Computing
    • Karol Niedzielewski
    • Marcin Semeniuk
    • Jarosław Skomiał
    • Jerzy Proficz
    • Piotr Sumionka
    • Bartosz Pliszka
    • Marek Michalewicz
    2020 Pełny tekst Supercomputing Frontiers and Innovations

    Collaboration between multiple computing centres, referred as federated computing is becom- ing important pillar of High Performance Computing (HPC) and will be one of its key components in the future. To test technical possibilities of future collaboration using 100 Gb optic fiber link (Connection was 900 km in length with 9 ms RTT time) we prepared two scenarios of operation. In the first one, Interdisciplinary Centre for Mathematical and Computational Modelling (ICM) in Warsaw and Centre of Informatics – Tricity Academic Supercomputer & networK (CI- TASK) in Gdan ́sk prepared a long distance geographically distributed computing cluster. System consisted of 14 nodes (10 nodes at ICM facility and 4 at TASK facility) connected using Infini- Band. Our tests demonstrate that it is possible to perform computationally intensive data analysis on systems of this class without substantial drop in performance for a certain type of workloads. Additionally, we show that it is feasible to use High Performance Parallex [1], high level abstrac- tion libraries for distributed computing, to develop software for such geographically distributed computing resources and maintain desired efficiency. In the second scenario, we prepared distributed simulation - postprocessing - visualization workflow using ADIOS2 [2] and two programming languages (C++ and python). In this test we prove capabilities of performing different parts of analysis in seperate sites.

  • Long-Period Gratings and Microcavity In-Line Mach Zehnder Interferometers as Highly Sensitive Optical Fiber Platforms for Bacteria Sensing
    • Tinko Eftimov
    • Monika Janik
    • Marcin Koba
    • Mateusz Śmietana
    • Predrag Mikulic
    • Wojtek J. Bock
    2020 Pełny tekst SENSORS

    Selected optical fiber sensors offer extraordinary sensitivity to changes in external refractive (RI), which make them promising for label-free biosensing. In this work the most sensitive ones, namely long-period gratings working at (DTP-LPG) and micro-cavity in-line Mach-Zehnder interferometers (µIMZI) are discussed for application in bacteria sensing. We describe their working principles and RI sensitivity when operating in water environments, which is as high as 20,000 nm/RIU (Refractive index unit) for DTP-LPGs and 27,000 nm/RIU for µIMZIs. Special attention is paid to the methods to enhance the sensitivity by etching and nano-coatings. While the DTP-LPGs offer a greater interaction length and sensitivity to changes taking place at their surface, the µIMZIs are best suited for investigations of sub-nanoliter and picoliter volumes. The capabilities of both the platforms for bacteria sensing are presented and compared for strains of Escherichia coli, lipopolysaccharide E. coli, outer membrane proteins of E. coli, and Staphylococcus aureus. While DTP-LPGs have been more explored for bacteria detection in 102–106 Colony Forming Unit (CFU)/mL for S. aureus and 103–109 CFU/mL for E. coli, the µIMZIs reached 102–108 CFU/mL for E. coli and have a potential for becoming picoliter bacteria sensors.

  • LONG-TERM RISK CLASS MIGRATIONS OF NON-BANKRUPT AND BANKRUPT ENTERPRISES
    • Tomasz Korol
    2020 Pełny tekst Journal of Business Economics and Management

    This paper investigates how the process of going bankrupt can be recognized much earlier by enterprises than by traditional forecasting models. The presented studies focus on the assessment of credit risk classes and on determination of the differences in risk class migrations between non-bankrupt enterprises and future insolvent firms. For this purpose, the author has developed a model of a Kohonen artificial neural network to determine six different classes of risk. Long-term analysis horizon of 15 years before the enterprises went bankrupt was conducted. This long forecasting horizon allows one to identify, visualize and compare the intensity and pattern of changes in risk classes during the 15-year trajectory of development between two separate groups of companies (150 bankrupt and 150 non-bankrupt firms). The effectiveness of the forecast of the developed model was compared to three popular statistical models that predict the financial failure of companies. These studies represent one of the first attempts in the literature to identify the long-term behavioral pattern differences between future “good” and “bad” enterprises from the perspective of risk class migrations.

  • Looking for the Optimal Location of an Eco-District within a Metropolitan Area: The Case of Tricity Metropolitan Area
    • Julia Kurek
    • Justyna Martyniuk-Pęczek
    2020 Pełny tekst Sustainability

    Compact housing structures located in city centers are considered to be the most energy and environmentally eective, mainly due to the access to services, transport networks and municipal infrastructures. There is the question of why so many of the acknowledged ecological housing complexes are located on the outskirts of cities or suburbs. Numerous cities decide to introduce strategies either to densify city centers, hoping to improve energy eciency. The Tricity metropolitan area is a special case undergoing dynamic transformation, and its development overlaps with the processes of both planned densification of the center as well as uncontrolled suburbanization. The goal of this study was to find the correlation between optimal location of an eco-district from the functional center of the Tricity metropolitan area, allowing for the most favorable energy and environmental parameters related both to the architectural and urban scale. The research was conducted in four dierent scenarios, concerning present and future development. In these scenarios, specific locations were examined, and the following were compared: total energy consumption, ecological footprint and CO2 lifecycle emissions. This study shows the possibility for suburban housing complexes with appropriate parameters in an edge city model to have the same or better results than complexes situated closer to the functional center of the city. This is mainly due to the building’s energy eciency, sustainable mobility, municipal infrastructure and relevant service access. The research proves the importance of implementing sustainable energy-saving and environmentally oriented activities at both an architectural and urban scale planning process.

  • Love your mistakes!—they help you adapt to change. How do knowledge, collaboration and learning cultures foster organizational intelligence?
    • Wioleta Kucharska
    • Denise A. D. Bedford
    2020 Pełny tekst JOURNAL OF ORGANIZATIONAL CHANGE MANAGEMENT

    Purpose: The study aims to determine how the acceptance of mistakes is related to adaptability to change in a broad organizational context. Therefore it explores how knowledge, collaboration, and learning culture (including “acceptance of mistakes”) might help organizations overcome their resistance to change. Methodology: The study uses two sample groups: students aged 18–24 (330 cases) and employees aged >24 (326 cases) who work in knowledge-driven organizations. Structural equation models were developed, assessed, and compared. Findings: The effect of the “learning climate” on “adaptability to change” mediated by “acceptance of mistakes” has been detected for young students aged 18-24; however this relationship is not significant for business employees aged >24. This result suggests that organizations, unlike universities, do not use mistakes as a tool to support learning that is to lead to change. Limitations: Both samples used in the study come from Poland. The business sample is in the majority represented by small and medium-sized enterprises. Therefore the presented findings may only apply to Poland. Practical implications: Acceptance of mistakes is vital for developing a learning culture. Mistakes help employees adapt to change. Hence, a learning culture that excludes the acceptance of mistakes is somehow artificial and may be unproductive. Paradoxically, the findings reveal that the fact that employee intelligence (adaptability to change) improves via mistakes does not mean that organizational intelligence will also increase. Thus, organizations that do not develop mechanisms of learning from mistakes lose the learning potential of their employees. Scientific implications: The study presents mistakes as a valuable resource that enables the adaptation and development of intelligence. Hence, this study brings to attention a promising research area of “learning from organizational mistakes” in the context of adaptability to change. The study should be replicated for large Polish companies, international companies, and other countries to get a total picture of this phenomenon. Moreover, the acceptance of mistakes would be a significant step to advance learning technologies. Novelty: This study proposes a constant learning culture scale that includes the “acceptance of mistakes” and “learning climate” dimensions. Further, it empirically proves the value of mistakes for adaptability to change.

  • Low energy differential elastic electron scattering from trichloromethane
    • B Diaz
    • G Tatreau
    • Borna Hlousek
    • Mateusz Zawadzki
    • Murtadha Khakoo
    2020 Pełny tekst Journal of Physics : Conference Series

    Experimental differential cross sections for low energy electron scattering from trichloromethane is measured utilizing a crossed electron-molecular beam experiment via the relative flow method, for the incident electron energies in the range of E = 0.5 eV-30 eV and the scattering angles in the range of θ = 10◦ − 130◦ .

  • Low energy elastic electron scattering from benzonitrile (C6H5CN)
    • G Tatreau
    • B Diaz
    • F Alharthi
    • Mateusz Zawadzki
    • Murtadha Khakoo
    2020 Pełny tekst Journal of Physics : Conference Series

    We present experimental differential elastic scattering cross sections (DCSs) for low energy electron scattering from benzonitrile along with integral and momentum-transfer cross sections that are determined from these DCSs. The measurements of DCSs are obtained using the relative flow method with helium as the standard gas, in a crossed electron-molecular gas beam arrangement. Our measurements are made at incident electron energies in the range of 1 − 30 eV and scattering angles in the range of (10◦ -130◦ ).

  • Low energy electron mass stopping power in H2
    • Mateusz Zawadzki
    • Murtadha Khakoo
    2020 Pełny tekst Journal of Physics : Conference Series

    We present experimental mass stopping powers of electrons in gaseous H2 obtained with a newly developed electron time-of-flight spectrometer, for the incident electron energy range of 10eV to 25eV. In our procedure the average energy loss is derived from our conversion of measured electron time-of-flight spectra into equivalent electron energy loss spectra so as to obtain the values of mass stopping power for electron scattering from H2.

  • Low energy inelastic electron scattering from carbon monoxide: I. excitation of the a3Π, a’3Σ+ and AΠ1 electronic states.
    • Mateusz Zawadzki
    • Morty Khakoo
    • Logan Voorneman
    • Luka Ratkovic
    • Zdenek Masin
    • Karel Houfek
    • Amar Dora
    • Russ Laher
    • Jonathan Tennyson
    2020 JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

    Differential scattering cross sections for electron excitation of the three lowest excited electron states of carbon monoxide are obtained experimentally using low-energy electron energy-loss spectroscopy and theoretically using the R-matrix method. The incident electron energies range from near-threshold of 6.3 eV to 20 eV. Experimental scattering angles range from 20◦ to 120◦. The normalization of the experimental cross sections is made to available experimental elastic scattering data (Gibson et al 1996 J. Phys. B: At. Mol. Opt. Phys. 29 3197). The R-matrix calculations use three distinct close-coupling models and their results are compared to available experimental and theoretical cross sections. The overall comparison leads to significantly improved description of the excitation cross sections for this target.

  • Low noise poroelastic road pavements based on modified asphalt binder
    • Jerzy Ejsmont
    • Beata Świeczko-Żurek
    • Władysław Gardziejczyk
    2020

    Tire/road noise is one of the most important environmental problems related to road traffic. As the most effective way to fight noise is reduction of sound emission from the source, a lot of work is being done to improve tire and road surfaces construction. This paper describes the first “road” results obtained within the SEPOR project, which is focused on developing a low noise poroelastic road surface based on bituminous binder. It is also a continuation of the paper presented during NOISE-CON 2019 conference that described the preliminary results of laboratory tests and small scale experiments. The paper presents results of measurements performed on two road sections paved with poroelastic material in 2019. The technologies used on these test sections were aimed at eliminating the problems that occurred with poroelastic surfaces using polyurethane binder and in particular increasing the durability of the surface (especially in terms of adhesion to the base layer) as well as reducing rolling resistance. The paper describes the results of tire noise, sound absorption, drainage properties and rolling resistance tests. Experience to date indicates that bituminous binder has eliminated the most troublesome problems of poroelastic road surfaces, but at this stage of development the achieved noise reduction is not as high as expected so more trials will be performed in 2020.

  • Low-Cost Automated Design of Compact Branch-Line Couplers
    • Adrian Bekasiewicz
    2020 Pełny tekst SENSORS

    Branch-line couplers (BLCs) are important components of wireless communication systems. Conventional BLCs are often characterized by large footprints which make miniaturization an important prerequisite for their application in modern devices. State-of-the-art approaches to design of compact BLCs are largely based on the use of high-permittivity substrates and multi-layer topologies. Alternative methods involve replacement of transmission-line sections of the circuit with their composite counterparts referred to as compact cells (CCs). Owing to efficient use of available space, CC-based couplers are often characterized by small footprints. Design of compact BLCs is normally conducted based on engineering experience. The process is laborious and requires many adjustments of topology followed by manual or, semi-automatic tuning of design parameters. In this work, a framework for low-cost automated design of compact BLCs using pre-defined CCs is proposed. Low cost of the presented design technique is ensured using equivalent-circuit models, space mapping correction methods, and trust-region-based local optimization algorithms. Performance of the framework is demonstrated using three examples concerning design of unequal-power split coupler, comparison of automatically generated compact BLCs, as well as rapid re-design of the coupler for different substrates. Furthermore, the approach has been benchmarked against the state-of-the-art methods for low-cost design of circuits.

  • Low-cost data-driven modelling of microwave components using domain confinement and PCA-based dimensionality reduction
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2020 IET Microwaves Antennas & Propagation

    Fast data-driven surrogate models can be employed as replacements of computationally demanding full-wave electromagnetic simulations to facilitate the microwave design procedures. Unfortunately, practical application of surrogate modelling is often hindered by the curse of dimensionality and/or considerable nonlinearity of the component characteristics. This paper proposes a simple yet reliable approach to cost-efficient modelling of miniaturized microwave components which adopts two fundamental mechanisms to improve the computational efficiency of setting up the surrogate. Firstly, the model domain is confined-using a set of pre-optimized reference designs-to the region of the parameter space containing high-quality designs with respect to the relevant performance figures. Secondly, the domain is spanned by the selected principal components of the reference set for dimensionality reduction. Consequently, the surrogate model, covering wide ranges of the device parameters and operating conditions, can be established using a fraction of training data samples required by conventional approaches, without compromising its predictive power. The proposed technique is illustrated using two miniaturized microstrip components: a rat-race coupler (RRC) and an impedance matching transformer. The following accuracies of the PCA-based surrogates have been obtained: 0.9% for RRC and 2.1% for the transformer (for 800 training data samples).

  • Low-cost performance-driven modelling of compact microwave components with two-layer surrogates and gradient kriging
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2020 Pełny tekst AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    Utilization of electromagnetic (EM) simulation tools has become indispensable for reliable evaluation of microwave components. As the cost of an individual analysis may already be considerable, the computational overhead associated with EM-driven tasks that require massive simulations (e.g., optimization) may turn prohibitive. One of mitigation methods is the employment of equivalent network models. Yet, they are incapable of accounting for cross-coupling effects that occur in devices of complex geometries. Another option are fast replacement models (surrogates), especially the data-driven ones: readily available, generic and problem independent. Unfortunately, due to the curse of dimensionality, their applicability is limited to low-dimensional parameter spaces and narrow parameter ranges. From the utility perspective, however, the surrogate has to be valid over broad ranges of parameters and operating conditions. The recently reported performance-modeling techniques (especially nested-kriging) allow for rendering such surrogates even for complex devices. Key concept is to carry out the modeling process within a confined domain, being a subset of the parameter space that encompasses the designs of high-quality regarding the performance figures of choice. The goal of this work is to reduce the cost of reference design acquisition, which adds up to the total cost of constructing the surrogate. Toward this end, gradient-enhanced kriging is incorporated into the performance-driven modeling framework. The predictive power of the surrogates rendered using our approach by far exceeds that of the conventional methods and is comparable to the original nested kriging technique while requiring a significantly smaller number of reference designs (thus, the CPU cost). These features are demonstrated using a three-section transformer and a rat-race coupler.

  • Low-Cost Surrogate Modeling of Miniaturized Microwave Components Using Nested Kriging
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2020 APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL

    In the paper, a recently reported nested kriging methodology is employed for modeling of miniaturized microwave components. The approach is based on identifying the parameter space region that contains high-quality designs, and, subsequently, rendering the surrogate in this subset. The results obtained for a miniaturized unequal-power-split rat-race coupler and a compact three-section impedance transformer demonstrate reliability of the method even for highly-dimensional parameter spaces, as well as its superiority over conventional modeling methods.

  • Low-Power Receivers for Wireless Capacitive Coupling Transmission in 3-D-Integrated Massively Parallel CMOS Imager
    • Grzegorz Blakiewicz
    • Miron Kłosowski
    • Waldemar Jendernalik
    • Jacek Jakusz
    • Stanisław Szczepański
    2020 Pełny tekst IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS

    The paper presents pixel receivers for massively parallel transmission of video signal between capacitive coupled integrated circuits (ICs). The receivers meet the key requirements for massively parallel transmission, namely low-power consumption below a single μW, small area of less than 205 μm2, high sensitivity better than 160 mV, and good immunity to crosstalk. The receivers were implemented and measured in a 3-D IC (two face-to-face stacked chips fabricated in CMOS 180 nm process). The maximum throughput of 20 Mbps of single receiver has been achieved using a return-to-zero (RZ) code. The static and dynamic power consumption of the single receiver are below 0.2 μW and 0.3 μW/MHz, respectively. The design approach for cost-effective inter-chip massively parallel transmission of photosensor signals with pulse position modulation (PPM) has been also performed. With this approach and the developed receivers it is possible to transfer between chips 9-10 bit images at a speed of over 1k fps.

  • LSTM-based method for LOS/NLOS identification in an indoor environment
    • Alicja Olejniczak
    • Olga Błaszkiewicz
    • Krzysztof Cwalina
    • Piotr Rajchowski
    • Jarosław Sadowski
    2020

    Due to the multipath propagation, harsh indoor environment significantly impacts transmitted signals which may adversely affect the quality of the radiocommunication services, with focus on the real-time ones. This negative effect may be significantly reduced (e.g. resources management and allocation) or compensated (e.g. correction of position estimation in radiolocalisation) by the LOS/NLOS identification algorithm. This paper investigates the idea of improving already existing method of LOS/NLOS classification, based on a deep feedforward neural network, by the LSTM-based model which allows extracting and analysing time-related dependencies occurring in a radio channel.

  • Machine Learning and Text Analysis in an Artificial Intelligent System for the Training of Air Traffic Controllers
    • Tetiana Shmelova
    • Yuliya Sikirda
    • Nina Rizun
    • Vitaliy Lazorenko
    • Volodymyr Kharchenko
    2020 Pełny tekst

    This chapter presents the application of new information technology in education for the training of air traffic controllers (ATCs). Machine learning, multi-criteria decision analysis, and text analysis as the methods of artificial intelligence for ATCs training have been described. The authors have made an analysis of the International Civil Aviation Organization documents for modern principles of ATCs education. The prototype of the neural network for evaluating the timeliness and correctness of the decision making by ATCs has been developed. The new theoretical and practical tasks for simulation and pre-simulation training have been obtained using expert judgment method. The methodology for sentiment analyzing the airline customers' opinions has been proposed. In addition, the examples of artificial intelligence systems and expert systems by the authors, students and colleagues from National Aviation University, Ukraine and Gdansk University of Technology, Poland have been proposed.