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Gdańsk University of Technology

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Publications from the year 2020

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  • Performance of organic coatings upon cyclic mechanical load
    • Michał Szociński
    • Kazimierz Darowicki
    2020 Full text PROGRESS IN ORGANIC COATINGS

    A number of engineering structures fail due to the fatigue damage resulting from cyclic mechanical stress. However, as far as organic coatings are concerned this degradation factor remains underestimated. In the paper the authors propose a methodology combining global electrochemical impedance spectroscopy and local atomic force microscopy measurements for evaluation of coating resistance to an impact of repetitive mechanical stress. Typical epoxy coating designated for ship hull protection has been tested in as-received state as well as after preexposure to elevated temperature. Application of atomic force microscopy-based approach helped to reveal and spatially localize the spots of organic coating degradation onset. The mechanism and process of defect formation and propagation has been shown on a microscopic scale.

  • Performance-Driven Surrogate Modeling of High-Frequency Structures
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2020

    The development of modern high-frequency structures, including microwave and antenna components, heavily relies on full-wave electromagnetic (EM) simulation models. Notwithstanding, EM-driven design entails considerable computational expenses. This is especially troublesome when solving tasks that require massive EM analyzes, parametric optimization and uncertainty quantification be-ing representative examples. The employment of fast replacement models, also referred to as surrogates, has been fostered as a way of mitigating these issues. Unfortunately, conventional modeling meth-ods are of limited applicability for handling nonlinear outputs of high-frequency devices. The reason is the curse of dimensionality but also a fundamental requirement that design-ready surrogates are to cover wide ranges of the system parameters and its operating con-ditions. This book offers a different methodological perspective on modeling of high-frequency structures, specifically, the concept and implementation of constrained or performance-driven surrogates. The presented approach addresses the issues of dimensionality and parameter ranges through appropriate confinement of the model do-main, focused on the regions that are promising from the point of view of the relevant design objectives. The performance-driven par-adigm enables the construction of reliable surrogates at a fraction of cost required by conventional methods, and to accomplish the mod-eling tasks where other techniques routinely fail. The book provides a broad selection of specific frameworks, extensively illustrated us-ing examples of real-world microwave and antenna structures. Ap-plications, including parametric optimization and multi-objective de-sign, are also discussed, along with the exposition of inverse model-ing methods. Furthermore, the book contains introductory material on data-driven and physics-based surrogates. Practical aspects of high-frequency surrogate modeling and recommendations concern-ing particular techniques are discussed as well.

  • Performance/energy aware optimization of parallel applications on GPUs under power capping
    • Adam Krzywaniak
    • Paweł Czarnul
    2020 Full text

    In the paper we present an approach and results from application of the modern power capping mechanism available for NVIDIA GPUs to the bench- marks such as NAS Parallel Benchmarks BT, SP and LU as well as cublasgemm- benchmark which are widely used for assessment of high performance computing systems’ performance. Specifically, depending on the benchmarks, various power cap configurations are best for desired trade-off of performance and energy con- sumption. We present two: both energy savings and performance drops for same power caps as well as a normalized performance-energy consumption product. It is important that optimal configurations are often non-trivial i.e. are obtained for power caps smaller than default and larger than minimal allowed limits. Tests have been performed for two modern GPUs of Pascal and Turing generations i.e. NVIDIA GTX 1070 and NVIDIA RTX 2080 respectively and thus results can be useful for many applications with profiles similar to the benchmarks executed on modern GPU based systems.

  • Person Tracking in Ultra-Wide Band Hybrid Localization System Using Reduced Number of Reference Nodes
    • Piotr Rajchowski
    • Jacek Stefański
    • Jarosław Sadowski
    • Krzysztof Cwalina
    2020 Full text SENSORS

    In this article a novel method of positional data integration in an indoor hybrid localization system combining inertial navigation with radio distance measurements is presented. A point of interest is the situation when the positional data and the radio distance measurements are obtained from less than thee reference nodes and it is impossible to unambiguously localize the moving person due to undetermined set of positional equations. The presented method allows to continuously provide localization service even in areas with disturbed propagation of the radio signals. Authors performed simulation and measurement studies of the proposed method to verify the precision of position estimation of a moving person in an indoor environment. It is worth noting that to determine the simulation parameters and realize the experimental studies the hybrid localization system demonstrator was developed, combining inertial navigation and radio distance measurements. In the proposed solution, results of distance measurements taken to less than three reference nodes are used to compensate the drift of the position estimated using the inertial sensor. In the obtained simulation and experimental results it was possible to reduce the localization error by nearly 50% regarding the case when only inertial navigation was used, additionally keeping the long term root mean square error at the level of ca. 0.50 m. That gives a degradation of localization precision below 0.1 m with respect to the fusion Kalman filtration when four reference nodes are present.

  • Perspektywa jakości w szkolnictwie wyższym. O modelu QualHE
    • Piotr Grudowski
    2020

    Kategoria jakości w szkolnictwie wyższym, choć tak ważna dla zapewnienia oczekiwanego tempa rozwoju państw i społeczeństw, ciągle jeszcze nie znajduje odpowiadającego jej randze odzwierciedlenia w pracach przedstawiających tę problematykę w sposób holistyczny, w odniesieniu do stale zmieniających się możliwości i wyzwań. Oddawana do rąk Czytelników monografia wnosi wkład w wypełnianie wspomnianej luki, przede wszystkim poprzez: • przedstawienie szerokiego kontekstu ogólnoświatowego dyskursu dotyczącego kategorii jakości w szkolnictwie wyższym w ujęciu teoriopoznawczym i w wynikach badań empirycznych; • określenie potencjału i uwarunkowań aplikacyjnych dotyczących takich koncepcji jak TQM Lean Management, Six Sigma czy Lean Six Sigma; • przedstawienie aktualnych trendów w zarządzaniu usługami publicznymi jako zbioru impulsów do zmian oraz tła dla projakościowej transformacji uczelni; • wskazanie możliwości wykorzystania opracowanych przez ISO najnowszych normatywnych systemów zarządzania; • zaakcentowanie roli kultury jakości jako elementu determinującego powodzenie wszelkich inicjatyw związanych z doskonaleniem procesów uczelni; • przedstawienie wyników kompleksowych badań interesariuszy polskiego systemu szkolnictwa wyższego na temat całokształtu projakościowych regulacji i zmian w uczelniach; • odniesienie perspektyw i wyzwań dotyczących zmian w szkolnictwie wyższym do koncepcji Przemysłu 4.0 i Jakości 4.0. Zaproponowany w książce oryginalny model systemu zarządzania jakością na uczelni – QualHE – odnosi się do wymienionych elementów, pokazując ich wzajemne relacje i dynamiczny charakter. Książka jest adresowana do badaczy zainteresowanych funkcjonowaniem systemów szkolnictwa wyższego, uczelni i poszczególnych jednostek organizacyjnych oraz kierunkami ich modernizacji. Powinna też spotkać się z zainteresowaniem praktyków – przedstawicieli kadry kierowniczej oraz pracowników działów jakości, coraz powszechniej tworzonych w strukturach uczelni. Może także stanowić kompendium wiedzy i inspirację do identyfikacji działań związanych z doskonaleniem organizacji dla osób reprezentujących różne grupy interesariuszy szkół wyższych, np. studentów, absolwentów, pracowników uczelni czy pracodawców.

  • Phage therapy as a novel strategy in the treatment of urinary tract infections caused by E. coli
    • Beata Zalewska-Piątek
    • Rafał Piątek
    2020 Full text Antibiotics-Basel

    Urinary tract infections (UTIs) are regarded as one of the most common bacterial infections affecting millions of people, in all age groups, annually in the world. The major causative agent of complicated and uncomplicated UTIs are uropathogenic E. coli strains (UPECs). Huge problems with infections of this type are their chronicity and periodic recurrences. Other disadvantages that are associated with UTIs are accompanying complications and high costs of health care, systematically increasing resistance of uropathogens to routinely used antibiotics, as well as biofilm formation by them. This creates the need to develop new approaches for the prevention and treatment of UTIs, among which phage therapy has a dominant potential to eliminate uropathogens within urinary tract. Due to the growing interest in such therapy in the last decade, the bacteriophages (natural, genetically modified, engineered, or combined with antibiotics or disinfectants) represent an innovative antimicrobial alternative and a strategy for managing the resistance of uropathogenic microorganisms and controlling UTIs.

  • Phenolic compounds from Nerium oleander leaves: microwave assisted extraction, characterization, antiproliferative and cytotoxic activities
    • Siham Ayouaz
    • Sheila Cristina Oliveira-Alves
    • Khalef Lefsih
    • Ana Teresa Serra
    • Andreia Bento da Silva
    • Madani Samah
    • Jakub Karczewski
    • Khodir Madani
    • Maria Rosário Bronze
    2020 Food & Function

    A microwave-assisted extraction (MAE) method was used for the extraction of phenolic compounds from Nerium oleander leaves. The influence of variables such as ethanol concentration, microwave power, irradiation time and liquid/solid ratio on polyphenol extraction was modelled using a second-order regression equation based on response surface methodology (RSM). The optimal conditions for MAE were: extraction solvent 35% ethanol concentration, 500 W microwave power, 60 s irradiation time and a solvent/material ratio of 20 mL g−1. Under optimal MAE conditions, the recovery of TPC was 25.752 mg GAE per g dw. 19 compounds have been identified by HPLC-ESI-MS/MS analysis; the main compounds identified were chlorogenic acid, rutin and quinic acid esters, such as caffeoylquinic acids and dicaffeoylquinic acids. Additionally, the optimized extract demonstrated potential to inhibit HT29 colorectal cancer cell growth (EC50 = 2.432 μg mL−1) without presenting cytotoxicity in confluent Caco-2 cells, a model of human intestinal epithelium. These results supply new information about the phenolic composition of Nerium oleander leaves and their antiproliferative effect.

  • Photochemical Rearrangement of a 19-Membered Azoxybenzocrown: Products and their Properties
    • Ewa Wagner-Wysiecka
    • Paulina Szulc
    • Elżbieta Luboch
    • Jarosław Chojnacki
    • Katarzyna Szwarc-Karabyka
    • Natalia Łukasik
    • Miłosz Murawski
    • Michał Kosno
    2020 Full text ChemPlusChem

    The preparation and characterization of products of the chemical and photochemical rearrangements of a 19-membered o,o'-azoxybenzocrown were presented. In photochemical rearrangement, besides expected product i.e. 19-membered o-hydroxy-o,o'-azobenzocrown (19-o-OH), obtained under defined conditions with 75% yield, also other macrocyclic products were isolated and identified, namely: 19-membered p-hydroxy-o,o'-azobenzocrown (19-p-OH), 21-membered o'-hydroxy-o,p'-azobenzocrown (21-o'-OH) and 19-membered macrocycle containing 5-membered ring bearing an aldehyde group (19-al). The structures of two atypical products of the photochemical rearrangement - 21-o'-OH and 19-al - were determined in the solid state by the X-ray method and in solution using NMR spectroscopy. Tautomeric equilibrium of the formed hydroxyazobenzocrowns and its change depending on acidity/basicity of the environment and alkali and alkaline earth metal cations complexation were studied using UV-Vis spectrophotometry, spectrofluorimetry and 1H NMR spectroscopy.

  • Photoinduced K+ Intercalation into MoO3/FTO Photoanode—the Impact on the Photoelectrochemical Performance
    • Mariusz Szkoda
    • Konrad Trzciński
    • Marcin Stanisław Łapiński
    • Anna Lisowska-Oleksiak
    2020 Full text Electrocatalysis

    In this work, thin layers of MoO3 were tested as potential photoanodes for water splitting. The influence of photointercalation of alkali metal cation (K+) into the MoO3 structure on the photoelectrochemical properties of the molybdenum trioxide films was investigated for the first time. MoO3 thin films were synthesized via thermal annealing of thin, metallic Mo films deposited onto the FTO substrate using a magnetron sputtering system. The Tauc and Mott–Schottky plots analysis were performed in order to determine the energy bands position of the investigated material. The photointercalation effect of K+ on photoelectrochemical properties of FTO/MoO3 photoanodes was studied using electrochemical techniques performed under simulated solar light illumination. It was proven that pristine MoO3 layers cannot act as effective photoanodes for water splitting due to the utilization of the photoexcited electrons in the intercalation process. The photochromic phenomenon related to Mo6+ centers reduction, and K+ intercalation occurs at a potential range in which the photoanode exhibits photoelectrochemical activity towards water photooxidation.

  • Photoplethysmographic Time-Domain Heart Rate Measurement Algorithm for Resource-Constrained Wearable Devices and its Implementation
    • Marek Wójcikowski
    • Bogdan Pankiewicz
    2020 Full text SENSORS

    This paper presents an algorithm for the measurement of the human heart rate, using photoplethysmography (PPG), i.e., the detection of the light at the skin surface. The signal from the PPG sensor is processed in time-domain; the peaks in the preprocessed and conditioned PPG waveform are detected by using a peak detection algorithm to find the heart rate in real time. Apart from the PPG sensor, the accelerometer is also used to detect body movement and to indicate the moments in time, for which the PPG waveform can be unreliable. This paper describes in detail the signal conditioning path and the modified algorithm, and it also gives an example of implementation in a resource-constrained wrist-wearable device. The algorithm was evaluated by using the publicly available PPG-DaLia dataset containing samples collected during real-life activities with a PPG sensor and accelerometer and with an ECG signal as ground truth. The quality of the results is comparable to the other algorithms from the literature, while the required hardware resources are lower, which can be significant for wearable applications.

  • Photoresponsive, amide-based derivative of embonic acid for anion recognition
    • Natalia Łukasik
    • Jarosław Chojnacki
    • Elżbieta Luboch
    • Andrzej Okuniewski
    • Ewa Wagner-Wysiecka
    2020 Full text JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

    The synthesis and ion-binding properties of amide-based derivative of embonic acid andp-aminoazobenzenewere described. The new compound was characterized by X-ray structural analysis and spectroscopic methods.Ligand interacts in acetonitrile with Y-shaped anions (benzoates and acetates) and dihydrogen phosphatesforming complexes of 1:1 stoichiometry. In more polar DMSO the complexes stoichiometry changes to 2:1(L:anion). Light-inducedtranstocisisomerization was studied. The effect of anions on thermal back iso-merization was investigated.

  • Photosensitive and pH-dependent activity of pyrazine-functionalized carbazole derivative as promising antifungal and imaging agent
    • Agnieszka Chylewska
    • Aleksandra Dąbrowska
    • Sandra Ramotowska
    • Natalia Maciejewska
    • Mateusz Olszewski
    • Maciej Bagiński
    • Mariusz Makowski
    2020 Full text Scientific Reports

    Carbazole skeleton plays a significant role as a structural scaffold of many pharmacologically active compounds. Pyrazine-functionalized carbazole derivative was constructed by coupling 2-amino-5-bromo-3-methylaminepyrazine (ABMAP) into 3 and 6 positions of the carbazole ring. Multi-experimental methods were used, e.g., potentiometric, spectroscopic (ATR, UV, XRD powder,1H and13C NMR), electrochemical (cyclic voltammetry), and optical techniques, to receive the complete structural analysis, physicochemical (pKa, logP) and biological profile of a new carbazole derivative with acronym 3,6-PIRAMICAR. The interaction ability of the compound studied with potential cellular targets like Calf Thymus DNA (CT-DNA), or Bovine Serum Albumin (BSA) were also taken into account. Experiments showed the existence of strong binding, but no DNA or BSA cleavage was observed. The comparative analyzes of compounds anti-Candida action clearly show pH-dependent antifungal activity of 3,6-PIRAMICAR, which was strongly stimulated in the acidic media. Surprisingly, the titled compound turn out to be much more effective (14 times by MIC50; 8 times by MIC; c.a. 4 times by MFC) against Candida krusei than fluconazole at pH 4.

  • Physicochemical and Mechanical Performance of Freestanding Boron-Doped Diamond Nanosheets Coated with C:H:N:O Plasma Polymer
    • Michał Rycewicz
    • Łukasz Macewicz
    • Jiri Kratochvil
    • Alicja Stanisławska
    • Mateusz Ficek
    • Mirosław Sawczak
    • Vitezslav Stranak
    • Marek Szkodo
    • Robert Bogdanowicz
    2020 Full text Materials

    The physicochemical and mechanical properties of thin and freestanding heavy boron-doped diamond (BDD) nanosheets coated with a thin C:H:N:O plasma polymer were studied. First, diamond nanosheets were grown and doped with boron on a Ta substrate using the microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Next, the BDD/Ta samples were covered with nylon 6.6 to improve their stability in harsh environments and flexibility during elastic deformations. Plasma polymer films with a thickness of the 500–1000 nm were obtained by magnetron sputtering of a bulk target of nylon 6.6. Hydrophilic nitrogen-rich C:H:N:O was prepared by the sputtering of nylon 6.6. C:H:N:O as a film with high surface energy improves adhesion in ambient conditions. The nylon–diamond interface was perfectly formed, and hence, the adhesion behavior could be attributed to the dissipation of viscoelastic energy originating from irreversible energy loss in soft polymer structure. Diamond surface heterogeneities have been shown to pin the contact edge, indicating that the retraction process causes instantaneous fluctuations on the surface in specified microscale regions. The observed Raman bands at 390, 275, and 220 cm−1 were weak; therefore, the obtained films exhibited a low level of nylon 6 polymerization and short-distance arrangement, indicating crystal symmetry and interchain interactions. The mechanical properties of the nylon-on-diamond were determined by a nanoindentation test in multiload mode. Increasing the maximum load during the nanoindentation test resulted in a decreased hardness of the fabricated structure. The integration of freestanding diamond nanosheets will make it possible to design flexible chemical multielectrode sensors.

  • Phytoremediation—From Environment Cleaning to Energy Generation—Current Status and Future Perspectives
    • Anna Grzegórska
    • Piotr Rybarczyk
    • Andrzej Rogala
    • Dawid Zabrocki
    2020 Full text ENERGIES

    :Phytoremediationis a technology based on the use of green plants to remove, relocate, deactivate, or destroy harmful environmental pollutants such as heavy metals, radionuclides, hydrocarbons, and pharmaceuticals. Under the general term of phytoremediation, several processes with distinctively different mechanisms of action are hidden. In this paper, the most popular modes of phytoremediation are described and discussed. A broad but concise review of available literature research with respect to the dominant process mechanism is provided. Moreover, methods of plant biomass utilization after harvesting, with particular regard to possibilities of “bio-ore” processing for metal recovery, or using energy crops as a valuable source for bio-energy production (bio-gas, bio-ethanol, bio-oil) are analyzed. Additionally, obstacles hindering the commercialization of phytoremediation are presented and discussed together with an indication of future research trends.

  • Pierwsze laboratoria wysokich napięć na ziemiach polskich
    • Krystian Chrzan
    • Marek Olesz
    • Stanisław Wojtas
    2020 Full text Przegląd Elektrotechniczny

    W publikacji przedstawiono pierwsze laboratoria wysokich napięć w Gdańsku, Wrocławiu, Lwowie, Warszawie, Gródku oraz osoby, które przyczyniły się do ich powstania. Alfons Hoffmann na Pomorzu, Ignacy Mościcki i Stanisław Jasilkowski we Lwowie i Kazimierz Drewnowski w Warszawie należą do pionierów i propagatorów techniki wysokich napięć w Polsce. Podczas budowy na początku ubiegłego stulecia nowoczesnych laboratoriów wykorzystywali nowatorskie pomysły oraz produkty wiodących firm, m in. fabryki transformatorów Siemens-Schuckert.

  • Plan zarządzania danymi–jak skutecznie współpracować z naukowcami? Doświadczenia Centrum Kompetencji Otwartej Nauki przy Bibliotece Politechniki Gdańskiej
    • Piotr Krajewski
    • Magdalena Szuflita-Żurawska
    2020 Full text Biuletyn EBIB

    Każdy projekt naukowy wiąże się z gromadzeniem i przetwarzaniem danych badawczych. Zaplanowanie całego procesu zarządzaniaoraz udostępniania danych stanowi obecnie nie tylko dobryzwyczaj, ale i konieczność. Od 2019 r. wszystkie wnioski składane w konkursach o granty Narodowego Centrum Nauki (NCN) muszą zawierać plan zarzą-dzania danymi z najważniejszymi informacjami dotyczącymi miejsca przechowywania danych, jak będą one opisywane igdzie udostępniane. Przygotowanie takiego planu może niejednokrotnie stanowić wyzwaniedla naukowców, zwłaszcza waspekcie praw własności intelektualnej czy też odpowiedniego zabezpieczenia danych. Artykuł przedstawia działania Centrum Kompetencji Otwartej Nauki działającego przy Bibliotece Politechniki Gdańskiej,podjęte w celu wsparcia naukowców w tym zadaniu. Działalność pracowników centrum przebiega dwutorowo: z jednej strony prowadzone są szkolenia, na których naukowcy mogą zapoznać się z najważniejszymi elementami procesu zarządzania danymi, z drugiej strony wszystkie plany przygotowane przez naukowców Politechniki Gdańskiej są konsultowane oraz weryfikowane. Ponadto na zaproszenie NCN pracownicy Centrum Kompetencji przeprowadzili szkolenia dla bibliotekarzy oraz pracowników administracji z innych uczelni, którzy dzięki zdobytej wiedzy mogą teraz wspierać naukowców w swoich macierzystych instytucjach.

  • Planty, promenady, ringi. Śródmiejskie założenia pierścieniowe Gdańska, Poznania, Wrocławia i Krakowa
    • Łukasz Bugalski
    2020

    [notka wydawnicza] Okalają centra miast, określają ich strukturę urbanistyczną i wpływają na codzienne życie mieszkańców. Planty, promenady i ringi – które autor nazywa ogólnie założeniami pierścieniowymi – są charakterystyczne dla wielu polskich miast. Powstały w miejscu dawnej granicy miasta – średniowiecznych murów lub nowożytnych bastionów ziemnych. Dziś stanowią atrakcyjną przestrzeń publiczną wypełnioną alejami, bulwarami i parkami bądź jej przeciwieństwo: jednorodny obszar zdominowany przez arterie komunikacyjne. Łukasz Bugalski definiuje, czym są założenia pierścieniowe, i zarysowuje szeroki kontekst ich powstawania – zarówno historyczny, jak i teoretyczny. Książkę wieńczy analiza czterech przypadków obrazujących zróżnicowany charakter założeń pierścieniowych: Gdańska, Poznania, Wrocławia i Krakowa.

  • Plasticity of Bead-On-Plate Welds Made with the Use of Stored Flux-Cored Wires for Offshore Applications
    • Aleksandra Świerczyńska
    • Michał Landowski
    2020 Full text Materials

    Extreme atmospheric conditions in the marine and offshore industry are harmful to engineering materials, especially to welded joints, and may cause degradation of their properties. This article presents the results of research on the plasticity of bead-on-plate welds made using two types of seamless, copper plated flux-cored wires. Before welding, spools with wire were stored for 1 month in two distinct locations with different geographical and industrial conditions in Poland, and then subjected to visual examination. Bead-on-plate welds were subjected to a static tensile test and on this basis plasticity indexes showing the effect of storage on plasticity were determined. The fractures after tensile tests and the surfaces of the wires were examined on an electron scanning microscope. Additionally, diffusible hydrogen content in deposited metal measurements for each condition were carried out. The highest degradation level was found for wire stored in an agricultural building in north-eastern Poland—there was an almost fourfold decrease in the plasticity index value and the highest diffusible hydrogen content. For the same wire and the same location, the largest difference was also observed in fracture morphology after the tensile test—ductile fracture was obtained for wire at delivery condition while an almost full cleavage fracture was found after relatively short (1 month) storage of wire.

  • Playing the Sprint Retrospective: A Replication Study
    • Yen Ying Ng
    • Jędrzej Skrodzki
    • Maciej Wawryk
    2020

    The Sprint Retrospective is a vehicle for continuous process improvement. Even though it is a well established agile practice, running effective retrospective meetings is challenging. There have been a lot of identified problems that commonly occur during these meetings. To address them, Przybyłek & Kotecka [20] successfully revitalized retrospective meetings by adopting collaborative games, which represent a powerful tool in improving interactions among team members. In this paper, we report on a replication of their study in Bluebay Poland and IHS Markit Gdańsk. The received feedback confirms the original findings and indicates that game-based retrospectives improve team members’ creativity, involvement, and communication as well as produce better results than the standard retrospectives. This paper is an extended version of our previous work [25].

  • Płynne przestrajanie pasma filtru ułamkowoopóźniającego z wykorzystaniem funkcji sklejanych
    • Marek Blok
    2020 Full text Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Przedstawiona metoda projektowania filtrów ułamkowoopóźniających definiowanych w dziedzinie częstotliwości umożliwia, poza określeniem jego opóźnienia, swobodne sterowanie szerokością pasma. Przestrajanie pasma filtru jest tu realizowane z użyciem funkcji sklejanych trzeciego stopnia, interpolujących współczynniki definiujące charakterystykę częstotliwościową. Zaproponowane rozwiązanie odpowiada użyciu metody okien przesuwanych, stąd użycie tych filtrów pozwala na sterowanie chwilową szerokością pasma w algorytmie zmiany szybkości próbkowania.