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Application of regularized Savitzky–Golay filters to identification of time-varying systems
PublicationSavitzky–Golay (SG) filtering is a classical signal smoothing technique based on the local least squares approximation of the analyzed signal by a linear combination of known functions of time (originally — powers of time, which corresponds to polynomial approximation). It is shown that the regularized version of the SG algorithm can be successfully applied to identification of time-varying finite impulse response (FIR) systems....
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A convergence result for mountain pass periodic solutions of perturbed Hamiltonian systems
PublicationIn this work, we study second-order Hamiltonian systems under small perturbations. We assume that the main term of the system has a mountain pass structure, but do not suppose any condition on the perturbation. We prove the existence of a periodic solution. Moreover, we show that periodic solutions of perturbed systems converge to periodic solutions of the unperturbed systems if the perturbation tends to zero. The assumption on...
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Accurate design of pseudoelliptic inline SIW filters with frequency-dependent couplings
PublicationThis paper presents an accurate synthesis method for inline SIW (Substrate Integrated Waveguide) generalized Chebyshev bandpass filters with frequency-dependent couplings. The technique is based on the synthesis of a coupling matrix that takes into account the impedance of the frequency-dependent stub. Thus, a loading effect compensation in adjacent resonators (via resonant frequency adjustment) and coupling elements (via coupling-value...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Sensorless IPMSM drive with rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes a sensorless Interior Permanent Magnet Synchronous Motor (IPMSM) drive designed for traction applications. Wide-speed sensorless operation is provided with the use of three methods of rotor position estimation designed for: a standstill, low- and high-speed range. The paper focuses on the high-speed estimation algorithm. The estimator uses the derivatives of motor phase currentsresulting from PWM modulation...
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Preliminary designing method of external pressure vessels for sea subsurface aplications
PublicationThis paper describes a unique engineering method intended for the preliminary designing of marine subsurface buoy mooring systems. The solved designing problem consists in determining geometrical parameters and selecting structural materials for a vessel of a buoyancy necessary to contain measuring instruments of a given mass, as well as its maximum dimensions and operational submersion depth. The assumed variability range of...
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Application of Barycentric Coordinates in Space Vector PWM Computations
PublicationThis paper proposes the use of barycentric coordinates in the development and implementationof space-vector pulse-width modulation (SVPWM) methods, especially for inverters with deformed space-vector diagrams. The proposed approach is capable of explicit calculation of vector duty cycles, independentof whether they assume ideal positions or are displaced due to the DC-link voltage imbalance. The use ofbarycentric coordinates also...
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The Importance of Demand and Environment for Defining and Establishing the Role of Data Stewards
PublicationData stewardship is now a central part of FAIR research data management. Although various types of positions called data stewards have been created at academic institutions over the last years, no demand-oriented, formal model of data stewardship and the associated roles exist so far. This workshop report presents the outcomes of the panel discussion “The Importance of Demand and Environment for Defining Data Stewardship” held...
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Analiza systemu zabezpieczeń dla internetowego portalu typu Online Judge
PublicationPrzedmiotem rozważań jest powszechnie dostępny portal internetowy pozwalający na organizację zawodów programistycznych. System taki, określany popularnie jako online judge lub online contester, udostępnia użytkownikom do rozwiązania zestaw zadań o charakterze algorytmicznym. Reguły konkursów oraz treści i zasady oceny poszczególnych zadań ustalane są przez uprzywilejowanych użytkowników zarządzających swoimi konkursami poprzez...
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Thermal buckling of functionally graded piezomagnetic micro- and nanobeams presenting the flexomagnetic effect
PublicationGalerkin weighted residual method (GWRM) is applied and implemented to address the axial stability and bifurcation point of a functionally graded piezomagnetic structure containing flexomagneticity in a thermal environment. The continuum specimen involves an exponential mass distributed in a heterogeneous media with a constant square cross section. The physical neutral plane is investigated to postulate functionally graded material...
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Cattaneo–Christov heat flow model for copper–water nanofluid heat transfer under Marangoni convection and slip conditions
PublicationThis report is devoted to the study of the flow of MHD nanofluids through a vertical porous plate with a temperature-dependent surface tension using the Cattaneo–Christov heat flow model. The energy equation was formulated using the Cattaneo–Christov heat flux model instead of Fourier’s law of heat conduction. The Tiwari–Das model was used to take into account the concentration of nanoparticles when constructing the momentum equation....
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Behavior of residual current devices at frequencies up to 50 kHz
PublicationThe use of residual current devices (RCDs) is obligatory in many types of low-voltage circuits. They are devices that ensure protection against electric shock in the case of indirect contact and may ensure additional protection in the case of direct contact. For the latter purpose of protection, only RCDs of a rated residual operating current not exceeding 30 mA are suitable. Unfortunately, modem current-using equipment supplied...
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Methylmercury and total mercury content in soft tissues of two bird species wintering in the Baltic Sea near Gdansk, Poland
PublicationOf the various forms of Hg occurring in nature, (mono) methylmercury (MeHg) is an especially toxic form and practically all forms of Hg can be converted into MeHg as a result of natural processes. Total mercury (THg) and MeHg were determined in tissues of two piscivorous birds: razorbill Alca torda and black-throated loon Gavia arctica to provide baseline data on current mercury concentrations for liver, kidneys and pectoral muscle...
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Multi-Channel Virtual Instrument for Measuring Temperature—A Case Study
PublicationThe article presents the hardware and software configuration of the developed multi-channel temperature measurement system as well as calibration procedures and measurement results verifying the properties of measurement channels. The system has been developed and dedicated primarily for measuring the temperature distribution in a laboratory model simulating underground power lines. With the adopted configuration of the analog...
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Optoelektroniczny monitoring stanu wzbudzenia plazmy niskotemperaturowej w procesach syntezy optycznych warstw diamentopodobnych
PublicationZrealizowana praca jest jednym z głównych zadań wieloletniego projektu badawczego z zakresu syntezy warstw diamentopodobnych. Celem bezpośrednim pracy było określenie rozkładu wzbudzenia plazmy w komorze technologicznej stanowiska PA ECR CVD. Głównym celem było opracowanie optoelektronicznego systemu pomiarowego, na którego potrzeby zastosowano przestrzennie selektywną optyczną spektroskopię emisyjną dedykowaną do badania procesu...
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Hydrophobic (deep) eutectic solvents (HDESs) as extractants for removal of pollutants from water and wastewater – A review
PublicationDeep eutectic solvents (DESs) are a new generation of solvents that attracted increasing attention in diverse applications. In last years, growing number of studies on hydrophobic (deep) eutectic solvents (HDESs) as an alternative extractants for various chemicals from aqueous environments have been reported. This article provides an overview on the usage of HDESs in liquid–liquid extraction (LLE) of different pollutants from water...
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Spatiotemporal Assessment of Satellite Image Time Series for Land Cover Classification Using Deep Learning Techniques: A Case Study of Reunion Island, France
PublicationCurrent Earth observation systems generate massive amounts of satellite image time series to keep track of geographical areas over time to monitor and identify environmental and climate change. Efficiently analyzing such data remains an unresolved issue in remote sensing. In classifying land cover, utilizing SITS rather than one image might benefit differentiating across classes because of their varied temporal patterns. The aim...
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Conjugates of Ciprofloxacin and Levofloxacin with Cell-Penetrating Peptide Exhibit Antifungal Activity and Mammalian Cytotoxicity
PublicationSeven conjugates composed of well-known fluoroquinolone antibacterial agents, ciprofloxacin (CIP) or levofloxacin (LVX), and a cell-penetrating peptide transportan 10 (TP10-NH2) were synthesised. The drugs were covalently bound to the peptide via an amide bond, methylenecarbonyl moiety, or a disulfide bridge. Conjugation of fluoroquinolones to TP10-NH2 resulted in congeners demonstrating antifungal in vitro activity against human...
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CeCu2O4 as a functional layer on solid oxide fuel cells for synthetic biogas reforming
PublicationSolid Oxide Fuel Cells (SOFC) are one of the most promising electrochemical devices, which can convert chemical energy to the electrical energy these days. Their ability to work with different kind of fuel makes them noteworthy. SOFC can work with biogas. The problem arises when solid carbon starts to be deposited in anode. That leads to degradation of fuel cell. Simple solution is to apply catalytic functional layer, which is...
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Wpływ uwarunkowań rzeczywistych na pracę równoległego filtru aktywnego sterowanego ze sprzężeniem od prądu zasilającego
PublicationW artykule przedstawiono wpływ uwarunkowań rzeczywistych na pracę równoległego filtru aktywnego i zdolność kompensacji prądów harmonicznych. Zbadano wpływ opóźnień czasowych wynikających z implementacji cyfrowej sterowania, wpływ impedancji zwarciowej sieci zasilającej oraz błędów generowania napięcia przekształtnika na jakość kompensacji filtru. Badania symulacyjne przeprowadzono dla trzech układów sterowania: otwartego, zamkniętego...
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Sterowanie stopniem wejściowym izolowanego wielopoziomowego przekształtnika kaskadowego DC-AC w napędzie EZT zasilanym z sieci trakcyjnej 3kV
PublicationW artykule przedstawiono wybraną problematykę sterowania wielopoziomowego przekształtnika DC-DC stanowiącego stopień wejściowy przekształtnika napędowego, przeznaczonego do napędów elektrycznych zespołów trakcyjnych (EZT). Sterowanie napędem trakcyjnym powinno uwzględniać właściwości sieci trakcyjnej 3kV DC: skokowe zmiany napięcia i przerwy w zasilaniu, m.in. spowodowane przejazdem odbieraka prądu przez izolatory sekcyjne. Proponowany...
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Methods of estimating the cost of traffic safety equipment’s life cycle
Publicationn the article, the authors discuss the preliminary information necessary to determine the scope and direction of further research conducted within the project called “The influence of time and operating conditions on the durability and functionality of road safety elements”. The main objective of the project is to develop the concept of a method for optimizing the life cycle costs of road safety devices. The authors draw attention...
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Implementacja automatycznych metod strojenia nastaw regulatora PID w sterowniku programowalnym
PublicationZainteresowanie środowiska przemysłowego klasycznymi algorytmami regulacji, dającymi akceptowalne wyniki pracy i stabilność w odniesieniu do zmiennych warunków otoczenia, wciąż jest bardzo duże. W artykule opisano wybrane inżynierskie metody doboru nastaw regulatora PID. Przedstawiono implementację sprzętową jednej z nich (metoda Åströma-Hägglunda) w sterowniku programowalnym PLC, umożliwiającą automatyczny dobór nastaw regulatora....
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Selection of C-Type Filters for Reactive Power Compensation and Filtration of Higher Harmonics Injected into the Transmission System by Arc Furnaces
PublicationThis article presents a method for selecting the elements of a C-type filter working with a conventional LC-type filter for compensating reactive power and filtering out higher harmonics generated by arc furnaces and ladle furnaces. The study was conducted in a steel mill supplied by a 110 kV transmission system, where higher harmonic currents and nonlinear loads were measured. A series of computer simulations were performed under...
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Application of vertical flow cw for highly contaminated wastewater treatment
PublicationBasing on quantitative and qualitative characteristics of reject waters generated during digested sewage sludge dewatering on centrifuges in conventional WWTP (RWC) and municipal landfill leachate (LL), the pilot constructed wetlands for treatment of both types of highly contaminated wastewater were designed. In the paper the characteristics of the pilot plants and assumed treatment efficiencies are presented. According to the...
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Displacement Sensors Based on the Phase of the Reflection Coefficient of a Split Ring Resonator Loaded Transmission Line
Publication— In this paper, novel displacement sensors using a microstrip loaded with a pair of split ring resonators (SRRs) are proposed. It is shown that the phase of the reflection coefficient from the loading SRRs can be used for displacement sensing. The paper also proposes a differential version of the sensor that benefits from a higher sensitivity and reference zero, which is useful for alignment purposes. It is further shown that...
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Nonlinearity shaping in nanostructured glass-diamond hybrid materials for optical fiber preforms
PublicationNanodiamond integration with optical fibers has proved a compelling methodology for magneto-optics. We reveal that the applicability of nanodiamonds in nonlinear optics goes beyond the previous demonstrations of frequency converters. Instead, we exploit the recently reported volumetric integration of nanodiamonds along the optical fiber core and show that the nonlinear response of glasses can be manipulated by nanodiamonds. By...
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Investigation of the electrochemical behaviour of AA1050 aluminium alloy in aqueous alkaline solutions using Dynamic Electrochemical Impedance Spectroscopy
PublicationThe paper presents the electrochemical behaviour of aluminium alloy AA1050 in aqueous alkaline media in the pH range 14–8.5. Electrochemical study was applied in order to obtain comprehensive information on the mechanism and kinetics of the process of anodic dissolution of aluminium, supplemented by monitoring of surface topography using an electron microscope. The corrosion rate of AA1050 increases with increasing concentration...
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Investigating Feature Spaces for Isolated Word Recognition
PublicationMuch attention is given by researchers to the speech processing task in automatic speech recognition (ASR) over the past decades. The study addresses the issue related to the investigation of the appropriateness of a two-dimensional representation of speech feature spaces for speech recognition tasks based on deep learning techniques. The approach combines Convolutional Neural Networks (CNNs) and timefrequency signal representation...
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Client-side versus server-side geographic data processing performance comparison: Data and code
PublicationThe data and code presented in this article are related to the research article entitled “Analysis of Server-side and Client-side Web-GIS data processing methods on the example of JTS and JSTS using open data from OSM and Geoportal” (Kulawiak et al., 2019). The provided 12 datasets include multi-point and multi-polygon data of different scales and volumes, representing real-world geographic features. The datasets cover the area...
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Wild oscillations in a nonlinear neuron model with resets: (I) Bursting, spike-adding and chaos
PublicationIn a series of two papers, we investigate the mechanisms by which complex oscillations are generated in a class of nonlinear dynamical systems with resets modeling the voltage and adaptation of neurons. This first paper presents mathematical analysis showing that the system can support bursts of any period as a function of model parameters, and that these are organized in a period-incrementing structure. In continuous dynamical...
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Semantics for an Interdisciplinary Computation
PublicationSemantics for an interdisciplinary computation is becoming increasingly difficult to capture while dealing with multi-domain problems. Expertise from Computer Science, Computer Engineering, Electrical Engineering, and other disciplines merges as engineering challenges in modern systems, such as, Cyber-Physical Systems, Smart Cities, and Bionic Systems must be tackled in a methodological manner. In this paper, a paradigm for formalization...
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Miniaturized dual‐band branch‐line coupler with enhanced bandwidth
PublicationIn this letter, a miniaturized hybrid dual-band branch-line coupler (BLC) with enhanced fractional bandwidths is proposed. Compact size and bandwidth enhancement are obtained using meandered transmission line sections with broken symmetry between cross-coupling branches. The circuit is designed at a low numerical cost using surrogate-assisted techniques. The optimized design features small size of only 0.25λg×0.19λg(28% miniaturization...
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Firing map of an almost periodic input function
PublicationIn mathematical biology and the theory of electric networks the firing map of an integrate-and-fire system is a notion of importance. In order to prove useful properties of this map authors of previous papers assumed that the stimulus function f of the system ẋ = f(t,x) is continuous and usually periodic in the time variable. In this work we show that the required properties of the firing map for the simplified model ẋ = f(t) still...
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Considerations of Adaptive Digital Communications in Underwater Acoustic Channel
PublicationDown-link communication (DLC) and air transportable communication (ATAC) buoys as well as autonomous underwater vehicles (AUV) use acoustic links for gathering oceanographic data from underwater monitoring systems. The underwater channel propagation conditions are diverse in nature and require a special adaptive approach to the communication system design. The article presents a methodology for the communication systems design,...
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Bearing capacity of monotonically installed tapered piles in medium dense Fontainebleau sand
PublicationA series of installation of tapered piles in medium-dense Fontainebleau sand were performed in the geotechnical centrifuge at Gustave Eiffel University. The models of piles with three different shapes - straight profile (S), and with taper angle of 0.70 degrees (T1), and 1.4 degrees (T2) were used. The piles were instrumented with fiber optic wires on the shaft and load cell at the base. After monotonic installation, the models were...
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Ekonomiczne aspekty strategii utrzymania torów kolejowych
PublicationW ostatnich lata coraz więcej uwagi poświęca się analizie kosztów cyklu życia (Life Cycle Cost - LCC) w zakresie planowania strategii utrzymania infrastruktury kolejowej. Większość prac ogranicza się jednak do kosztów bezpośrednich (planowanych), takich jak budowy, konserwacji, odnowienia i utylizacji. Takie podejście prowadzi do niedoszacowania kosztów wynikających z niskiej jakości geometrii toru. W artykule przedstawiona została...
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Analiza tłuszczów obecnych w surowcach stosowanych do produkcji czekolady
PublicationW pracy zbadano 28 próbek miazgi kakaowej, 12 próbek tłuszczu kakaowego i 6 próbek mleka w proszku w celu stwierdzenia, czy znajdujš się w nich obce tłuszcze. W przypadku miazgi kakaowej i tłuszczu kakaowego zastosowano metodę HPLC do analizy TAG. W przypadku tłuszczu wyekstrahowanego z mleka w proszku zastosowano metodę GLC do analizy składu kwasów tłuszczowych. W próbkach miazgi kakaowej i mleka w proszku nie stwierdzono obecności...
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The importance and availability of marine certified reference materials
PublicationTraceability and reliable results are the two pillars of analytical methods; certified reference materials (CRMs) meet this requirement. ISO 17034:2016 credentials provide brief information on general requirements for the competence of Reference Material Producers (RMPs). The different types of CRMs have been produced in recent years for chemical analysis in food, water, soil, and sediment matrices in recent years. This review...
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The life cycle cost of a building from the point of view of environmental criteria of selecting the most beneficial offer in the area of competitive tendering
PublicationThe article analyses environmental and ecological criteria of selecting the most beneficial offer in the aspect of LCC. Construction works contracts and the potential method of defining the above criteria, among others, is pondered on (for example by the recommendation of a material, which is supposed to be used, a ban on substances that are harmful for human health as well for the environment). In the relation to the above, it...
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Ocena techniczno-ekonomiczna stosowania pomp ciepła w systemach ogrzewania wolnostojących budynków mieszkalnych
PublicationW artykule przedstawiono ocene techniczno-ekonomiczną ogrzewania wolnostojącego budynku mieszkalnego, realizowanego w oparciu o dwa systemy. Analizę opłacalności przeprowadzono dla układów, których porównanie jest w wysokim stopniu adekwatne do rzeczywistych warunków ekonomicznych i technicznych. Ocenie poddano systemy c.o. i c.w.u. wykorzystujące sprężarkową pompę ciepła lub alternatywnie kocioł olejowy, przy założeniu, że parametry...
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Ograniczenia wirtualnego miernika impedancji opartego na karcie akwizycji danych
PublicationW artykule przedstawiono wirtualny miernik parametrów elementów RLC, zrealizowany w oparciu o komputer PC z zainstalowana kartą akwizycji danych(PCI-6040E) wyposażoną w przetworniki a/c i c/a. Analizowano właściwości metrologiczne miernika zależne od parametrów zastosowanej karty. Przeprowadzono badania symulacyjne błędu pomiaru pojemności uwzględniajace rozdzielczośc i częstotliwośc próbkowania przetwornika a/c oraz jego czas...
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Comparison of the content of phenolic compounds and antioxidant activity of white, red and black currants (Ribes sp.) extracts
PublicationThe aim of this study was to compare the content of antioxidant compounds and the antioxidant activity of extracts from white, red and black currants (Ribes sp.). The chemical properties verified included determinations of anthocyanins and other phenols by HPLC-DAD-MS, total antioxidant activity by standard spectrophotometric tests (ABTS, DPPH and FCR), and profiles of antioxidants by TLC with visualization reagents (ABTS, DPPH,...
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Management of Dark Fermentation Broth via Bio Refining and Photo Fermentation
PublicationLignocellulose and starch-based raw materials are often applied in the investigations regarding biohydrogen generation using dark fermentation. Management of the arising post-fermentation broth becomes a problem. The Authors proposed sequential processes, to improve the efficiency of both hydrogen generation and by-products management carried under model conditions. During the proposed procedure, the simple sugars remaining in...
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A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit
PublicationIn the paper, there is presented a new time-domain measurement method for determining the capacitance values of capacitive sensors, dedicated, among others, to capacitive relative humidity sensors. The method is based on a versatile direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators (ACs) and with precision voltage reference sources, e.g. digital-to-analog converters (DACs). The reference...
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Core loss resistance impact on sensorless speed control of an induction motor using hybrid adaptive sliding mode observer
PublicationInduction motors (IMs) experience power losses when a portion of the input power is converted to heat instead of driving the load. The combined effect of copper losses, core losses, and mechanical losses results in IM power losses. Unfortunately, the core losses in the motor, which have a considerable impact on its energy efficiency, are not taken into account by the generally employed dynamic model in the majority of the studies. Due...
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Providing Public Space Continuities in Post-Industrial Areas through Remodelling Land/Water Connections
PublicationThis article examines the problem of urban transformation strategies applied in recent years which are based on the creation of new water areas and modification of existing ones. The research is an attempt to prove that modifications of plans of water areas and forms of their borders may play an important role in achieving the best quality public spaces in post-industrial territories. The basis for demonstrating the importance...
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Digits Recognition with Quadrant Photodiode and Convolutional Neural Network
PublicationIn this paper we have investigated the capabilities of a quadrant photodiode based gesture sensor in the recognition of digits drawn in the air. The sensor consisting of 4 active elements, 4 LEDs and a pinhole was considered as input interface for both discrete and continuous gestures. Index finger and a round pointer were used as navigating mediums for the sensor. Experiments performed with 5 volunteers...
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Rapid Characterization of the Human Breast Milk Lipidome Using a Solid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry-Based Approach.
PublicationHuman breast milk (HBM) is a biofluid consisting of various biomolecules such as proteins, lipids, carbohydrates, minerals and bioactive substances. Due to its unique and complex composition, HBM provides not only nutritional components required for the growth of the infant, but also additional protection against infections. Global insight into the composition of HBM is crucial to understanding the health benefits infants receive...
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Average Redundancy of the Shannon Code for Markov Sources
PublicationIt is known that for memoryless sources, the average and maximal redundancy of fixed–to–variable length codes, such as the Shannon and Huffman codes, exhibit two modes of behavior for long blocks. It either converges to a limit or it has an oscillatory pattern, depending on the irrationality or rationality, respectively, of certain parameters that depend on the source. In this paper, we extend these findings, concerning the Shannon...