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New Algorithms for Adaptive Notch Smoothing
PublicationThe problem of extraction/elimination of a nonstationary complex sinusoidal signal buried in noise is considered. This problem is usually solved using adaptive notch filtering (ANF)algorithms. It is shown that accuracy of signal estimation can be increased if the results obtained from ANF are further processed using a cascade of appropriately designed filters. The resulting adaptive notch smoothing (ANS) algorithms can be employed...
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Identification of quasi-periodically varying systems with quasi-linear frequency changes
PublicationThe problem of identification of linear quasi-periodically varying systems is considered. This problem can be solved using generalized adaptive notch filtering (GANF) algorithms. It is shown that accuracy of system parameter estimation can be increased if the results obtained from GANF are further processed using a cascade of appropriately designed filters. The resulting generalized adaptive notch smoothing (GANS) algorithms can...
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Application of Complementary Signals in Built-In Self Testers for Mixed-Signal Embedded Electronic Systems
PublicationThis paper concerns the implementation of shape-designed complementary signals (CSs), matched to the frequency characteristic of the circuit under test, in built-in self testers (BISTs), dedicated to mixed-signal embedded electronic systems for testing their analog sections. The essence of the proposed method and solution of CS BIST is low-cost realization on the base of hardware and software resources of microcontrollers used...
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Efficiency of pollutant removal by five multistage constructed wetlands in a temperate climate
PublicationIn recent years, an increase in interest in hybrid constructed wetland systems (HCWs) has beenobserved. These systems are composed of two or more filters with different modes of sewage flow.Based on over eight years of monitoring, carried out at five local HCWs located in the PomeraniaRegion of Northern Poland, the effective removal of organic matter (from 74.9 to 95.5% COD) in theloading range 1.5-17.0 g COD·m-2·d-1 was confirmed....
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Hybrydowa koncepcja łagodzenia stromości zmian napięcia du/dt dla wielopoziomowych przekształtników kaskadowych SiC
PublicationW referacie zaproponowano nową hybrydową koncepcję łagodzenia stromości zmian napięcia du/dt w wielopoziomowych przekształtnikach kaskadowych SiC. Proponowana koncepcja polega na wykorzystaniu nietłumionego filtra du/dt, podatnego na rezonans oraz zastosowaniu w algorytmie sterowania PWM dodatkowych impulsów sterujących tranzystorami SiC MOSFET, wymuszających rezonansowe przełączanie napięcia na wyjściu filtra. Efekt zmniejszenia...
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Hybrydowa koncepcja łagodzenia stromości zmian napięcia du/dt dla wielopoziomowych przekształtników kaskadowych SiC
PublicationW referacie zaproponowano nową hybrydową koncepcję łagodzenia stromości zmian napięcia du/dt w wielopoziomowych przekształtnikach kaskadowych SiC. Proponoana koncepcja polega na wykorzystaniu nietłumionego filtra du/dt, podatnego na rezonans oraz zastosowaniu w algorytmie sterowania PWM dodatkowych impulsów sterujących tranzystorami SiC MOSFET, wymuszających rezonansowe przełączanie napięcia na wyjściu filtra. Efekt zmniejszenia...
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High-density Polyethylene - Expanded Perlite Composites: Structural Oriented Analysis of Mechanical and Thermomechanical Properties
PublicationAs part of this work, research was carried out on the effect of the addition of expanded perlite (PR) on the mechanical and thermomechanical properties of high-density polyethylene (PE) composites. Composites containing from 1 to 10 wt% of the inorganic filler were produced. Polyethylene-based composites manufactured by twin-screw extrusion and formed in the compression molding process were subjected to mechanical, thermomechanical,...
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Structural Assessment of Reinforced Concrete Beams Incorporating Waste Plastic Straws
PublicationThe behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The effect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3,...
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Two- and three-dimensional elastic networks with rigid junctions: modeling within the theory of micropolar shells and solids
PublicationFor two- and three-dimensional elastic structures made of families of flexible elastic fibers undergoing finite deformations, we propose homogenized models within the micropolar elasticity. Here we restrict ourselves to networks with rigid connections between fibers. In other words, we assume that the fibers keep their orthogonality during deformation. Starting from a fiber as the basic structured element modeled by the Cosserat...
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Photovoltaic Maximum Power Point Technique based on Incremental Conductance (INCON) control algorithm
PublicationMaximum output power status can significantly improve the deployment rate of solar energy system. In order to get the maximum power output, issue of tracking maximum power point (MPP), reduced harmonics around MPP and improve efficiency of the solar power energy system, this paper presents the improved maximum power point tracking (MPPT) control...
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Projektowanie filtrów cyfrowych IIR o nietypowych charakterystykach przy użyciu algorytmu ewolucji różnicowej
PublicationW artykule przedstawiono zastosowanie algorytmu ewolucji różnicowej do projektowania filtrów cyfrowych o nietypowych charakterystykach amplitudowych. Przy użyciu proponowanej metody zaprojektowano trzy filtry o charakterystykach: liniowo narastającej, liniowo opadającej oraz nieliniowo narastającej. Opisane tą metodą filtry są stabilne a ich charakterystyki amplitudowe spełniają wszystkie założenia projektowe.
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PRZEBIEG TEMPERATURY ZIM NA OBSZARZE POLSKI W LATACH 1720–2015
PublicationThe work discusses the air temperature course of winter periods (December–March) in Poland in the years 1720–2015. The analysis is carried out for area mean values calculated from 5 stations: Szczecin, Wrocław, Warsaw, Wilno and Lwów. The time series of the mean area winter temperature (hereinafter PLZ) consists of combined observational (140 years) and reconstructed (156 years) data. PLZ reconstruction is based on independent...
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Application of Fast Cameras to String Vibrations Recording
PublicationA hardware and software solution for guitar string vibration measurement by fast cameras is described. Orthogonal setup for 3D image acquisition is proposed capable to capture several thousand image frames per second. Dedicated image processing algorithm was developed and described in the paper, aimed at tracking the movement of some selected points along the string. Fast and accurate tracking results provided a detailed information...
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Eco-Friendly Electromagnetic Interference Shielding Materials from Flexible Reduced Graphene Oxide Filled Polycaprolactone/Polyaniline Nanocomposites
PublicationHybrid nanocomposites have the unique ability of enhancing material properties due to the existing synergistic effect of the fillers. In this study, the authors report such an eco-friendly hybrid nanocomposite comprising of polyaniline and reduced graphene oxide in polycaprolactone. The conducting polyaniline improved the processability of polycaprolactone, and the final composites were prepared by incorporating graphene oxide...
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RF Input-Quasi-Reflectionless Dispersive-Delay Structures Based on Complementary-Diplexer Circuits
PublicationA class of RF dispersive-delay structures (DDSs) with input-quasi-reflectionless behavior is reported. It is based on the exploitation of complementary-diplexer circuit networks, in which the out-of-band RF-input-power echoes reflected by the main bandpass-filter-(BPF)-type channel are dissipated by the resistively-terminated auxiliary bandstop-filter-(BSF)-type channel. Specifically, it is shown that the influence of the absorptive...
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Design and Implementation of a Dual-band Filtering Wil-kinson Power Divider Using Coupled T-shaped Dual-band Resonators
PublicationThe paper introduces a novel structure of a dual-band filtering Wilkinson power divider (WPD). Its essential component is a dual-band bandpass filter (BPF), implemented using coupling lines and two T-shaped resonators. The BPF is incorporated into the divider structure to suppress the unwanted harmonics within the circuit. The latter is achieved owing to a wide stopband of the filter. The deigned dual-band WPD can suppress third...
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Numerical modelling of the mesofracture process of sintered 316L steel under tension using microtomography
PublicationThis paper concerns numerical modelling of the deformation process, taking into account the local fracture of porous 316L sinters at the mesoscopic scale using the finite element method. Calculations are performed with the use of geometrical models, to map the realistic shape of the porous mesostructure of the material, obtained by means of computed microtomography. The microtomographic device has limited and insufficient measurement...
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Filtracja zakłóceń w obwodzie wyjściowym falownika napięcia w symulacji komputerowej
PublicationW referacie zamieszczono wyniki badań symulacyjnych układu filtru wejściowego falownika napięcia, połączonego z obwodem pośredniczącym przemiennika częstotliwości. Dokonano opisu matematycznego filtru oraz przy pomocy programu TCAD przeprowadzono analizę modelowego obwodu. Przedstawiono przebiegi prądów i napięć w układzie oraz amplitudy harmonicznych zawarte w prądzie wyjściowym falownika napięcia.
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The impact of thermomechanical and chemical treatment of waste Brewers’ spent grain and soil biodegradation of sustainable Mater-Bi-Based biocomposites
PublicationDue to the massive plastic pollution, development of sustainable and biodegradable polymer materials is crucial to reduce environmental burdens and support climate neutrality. Application of lignocellulosic wastes as fillers for polymer composites was broadly reported, but analysis of biodegradation behavior of resulting biocomposites was rarely examined. Herein, sustainable Mater-Bi-based biocomposites filled with thermomechanically-...
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Structural, thermal and physico-mechanical properties of polyurethane/brewers’ spent grain composite foams modified with ground tire rubber
PublicationIn this work, brewers’ spent grain (BSG) and ground tire rubber (GTR) waste fillers were applied as low-cost reinforcement phase in rigid polyurethane foam (PUR). PUR/BSG/GTR composites were prepared by a single step method, using polyglycerol as partial substitute of commercially available petrochemical polyols. Foaming parameters, chemical structure, dynamic mechanical properties, thermal stability, physico-mechanical properties...
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Intelligent monitoring the vertical dynamics of wheeled inspection vehicles
PublicationThe problem of intelligent monitoring of the vertical dynamics of wheeled inspection vehicles is addressed. With the independent MacPherson suspension system installed, the basic analysis focuses on the evaluation of the parameters of the so-called quarter car model. To identify a physically motivated continuous description, in practice, dedicated integral-horizontal filters are used. The obtained discrete model, which retains...
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Using deep learning to increase accuracy of gaze controlled prosthetic arm
PublicationThis paper presents how neural networks can be utilized to improve the accuracy of reach and grab functionality of hybrid prosthetic arm with eye tracing interface. The LSTM based Autoencoder was introduced to overcome the problem of lack of accuracy of the gaze tracking modality in this hybrid interface. The gaze based interaction strongly depends on the eye tracking hardware. In this paper it was presented how the overall the...
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The Application of the IODA Document Architecture to Music Data
PublicationThis paper is concerned with storing music data with the use of document architecture called Interactive Open Document Architecture (IODA). This architecture makes it possible to create documents which are executable, mobile, interactive and intelligent. Such documents consist of many files that are semantically related to each other. Semantic links are defined in XML files which are a part of a document. IODA documents with music...
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Detection of broadband signals in the field of aperture and array systems.
PublicationAnteny i szyki anten w dolnopasmowych systemach hydroakustycznych wnoszą istotne zniekształcenia liniowe wpływające na możliwości detekcji sygnałów szerokopasmowych. W artykule analizowany jest charakter takich zniekształceń metodą przestrzenno - czasowych odpowiedzi impulsowych. Sygnał odbierany w różnych kierunkach przestrzeni poddano filtracji na dwa sposoby z filtrem dopasowanym do sygnału nadawanego i filtrem dopasowanym...
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Reduced order models in computational electromagnetics (in memory of Ruediger Vahldieck)
PublicationThis paper reviews research of Ruediger Vahldieck's group and the group at the Gdansk University of Technology in the area of model order reduction techniques for accelerating full-wave simulations. The applications of reduced order models to filter design as well as of local and nested(multilevel) macromodels for solving 3D wave equations and wave-guiding problems using finite difference and finite element methods are discussed.
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Sensorless Control of Induction Machine Supplied by Current Source Inverter
PublicationThe paper describes the voltage control technique of induction machines supplied by a current source inverter. The control system is based on proposed new multi-scalar variables, which are named “r.” The control system contains the output filter capacitor's model. In the sensorless control system the Z type backstepping speed observer was applied. The mathematical dependences are confirmed by simulation and experimental research.
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Interconnection of the Customer-Side Resources Using Single Phase VAPF
PublicationThe paper introduces method for utilization of the customer-side generated energy using single phase voltage active power filter. Structure and control method of the power electronics converter has been described and some simulation results are shown to prove usefulness of this arrangements. Proposed application realizes the following functions: power quality improvement, uninterruptible supplying and energy costs reduction.
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Influence of accelerometer signal pre-processing and classification method on human activity recognition
PublicationA study of data pre-processing influence on accelerometer-based human activity recognition algorithms is presented. The frequency band used to filter-out the accelerometer signals and the number of accelerometers involved were considered in terms of their influence on the recognition accuracy. In the test four methods of classification were used: support vector machine, decision trees, neural network, k-nearest neighbor.
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User Authentication by Eye Movement Features Employing SVM and XGBoost Classifiers
PublicationDevices capable of tracking the user’s gaze have become significantly more affordable over the past few years, thus broadening their application, including in-home and office computers and various customer service equipment. Although such devices have comparatively low operating frequencies and limited resolution, they are sufficient to supplement or replace classic input interfaces, such as the keyboard and mouse. The biometric...
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Dielectric properties of modified graphene oxide filled polyurethane nanocomposites and its correlation with rheology
PublicationThis study aims at investigating the dynamic mechanical, dielectric and rheological properties of reinforced polyurethane (PU) nanocomposites containing hydrophilic graphene oxide (GO) and/or hydrophobic modified graphene oxide (mGO) sheets. The organic modification of GO was performed with 4,4′-methylenebis (phenyl isocyanate) (MDI) and the samples were prepared by solvent mixing. We found that addition of mGO provides a more...
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More than just a beer—the potential applications of by-products from beer manufacturing in polymer technology
PublicationBeer is the most popular alcoholic beverage in the world, and its popularity is continuously growing. Currently, global beer production is estimated at around 2 billion hectoliters. Nevertheless, the increasing production capacity implicates the rising issue of generated by-products—brewers’ spent grain, spent hops, spent yeast, and wastewater. They are generated in massive amounts, so having in mind the current pro-ecological...
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Zmienność termicznego charakteru okresów zimowych w Polsce i jej przyczyny
PublicationPraca przybliża problematykę funkcjonowania fenomenu klimatycznego Oscylacji Północnego Atlantyku (Norh Atlantic Oscillation – NAO) oraz omawia jej wpływ na kształtowanie charakteru termicznego zim (grudzień – marzec) na obszarze Polski. Zmiana faz NAO z w przewadze ujemnych na w przewadze dodatnie, jaka nastąpiła w latach 1987-1989 spowodowała, że po roku 1989 obserwuje się w Polsce znaczne złagodzenie stopnia ostrości zim.
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Estimation of the amplitude of the signal for the active optical gesture sensor with sparse detectors
PublicationIn this paper we deal with the problem of precise gesture recognition for the active optical proximity sensor with sparse 8 photodiodes. We particularly focus on developing the method of estimating the real, usually not observable, maximum signal value representing maximum intensity of light reflected from an obstacle present in the front of the sensor. Different configurations of the fingers were used as an obstacle. The Monte Carlo...
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GOOD HEALTH PRODUCTS AND POLYMER COMPOSITES OBTAINED WITH THE USE OF NATURAL ORIGIN MICRO- AND NANOFIBERS
PublicationThe aim of this work was focused on good health products and polymer composites obtained with the use of natural origin micro- and nanofibers. Many different type of the natural plants are used in the production of good health products and polymer processing like curcuma, cellulose, microalgae and others. Often are used as a antioxidants and fillers. In this work the effect of algae and cellulose as a microfillers on the chosen...
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Sample Rate Conversion with Fluctuating Resampling Ratio
PublicationIn this paper a sample rate conversion with continuouslychanging resampling ratio has been presented. The proposed implementation is based on variable fractional delay filter implemented using a Farrow structure. It have been demonstrated that using the proposed approach instantaneous resampling ratio can be freely changed. This allows for simulation of audio recored on magnetic tape with nonuniform velocity as well as removal...
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A New Method of Noncausal Identification of Time-varying Systems
PublicationThe paper shows that the problem of noncausal identification of a time-varying FIR (finite impulse response) sys- tem can be reformulated, and solved, as a problem of smoothing of the preestimated parameter trajectories. Characteristics of the smoothing filter should be chosen so as to provide the best trade- off between the bias and variance of the resulting estimates. It is shown that optimization of the smoothing operation can...
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Post-comatose patients with minimal consciousness tend to preserve reading comprehension skills but neglect syntax and spelling
PublicationModern eye tracking technology provides a means for communication with patients suffering from disorders of consciousness (DoC) or remaining in locked-in-state. However, being able to use an eye tracker for controlling text-based contents by such patients requires preserved reading ability in the first place. To our knowledge, this aspect, although of great social importance, so far has seemed to be neglected. In the paper, we...
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Rigid polyurethane foams with different flame retardants and their physical and mechanical properties
PublicationRigid polyurethane foams (PUFs) containing 3, 6 or 9 % of one of of two selected fire retardants (FR): oligomeric ethyl ethylene phosphate (Fyrol PNX) and expandable graphite (EG) were prepared, inspected and compared to foam without that fillers as the control. The thermal stability of PUFs was described by horizontal test according to norm: UL 94 HB. Compressive strength and physical properties (density, fragility and water absorption)...
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Nonlinear fuzzy control of the dissolved oxygen in activated sludge processes
PublicationWastewater treatment plant is generally a complex, multivariable, time varying and nonlinear large scale industrial system. Moreover, interactions between the components are very strong. The dissolved oxygen tracking problem is one of the most complex and fundamental issues of biological processes. Air for the aerated tanks is supplied by aeration system (blowers, pipes, diffusers). It is a complex dynamic system. The new control...
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Sample Rate Conversion with Fluctuating Resampling Ratio
PublicationIn this paper a sample rate conversion with continuously changing resampling ratio has been presented. The proposed implementation is based on variable fractional delay filter implemented using a Farrow structure. It have been demonstrated that using the proposed approach instantaneous resampling ratio can be freely changed. This allows for simulation of audio recored on magnetic tape with nonuniform velocity as well as removal...
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Linking music data in executable documents
PublicationThis paper presents the application of Interactive Open Document Architecture (IODA) to music and video data. This architecture was design to create multilayer documents which consist of many files. The paper shows the method of creating media documents on the basis of IODA. These kind of documents were called IODA Media Documents (IMD). IMD have links that connect many different kinds of files containing music and video data....
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Shape-Memory Polyurethane Polymers
PublicationPolyurethanes (PUs) are one of the most widely used polymers in research and industry. They can be synthesized from chemical sources and natural sources. PUs are a very useful class of polymers and exhibit many desirable properties that can be exploited in various applications. PUs are formed by the reaction between polyols and isocyanates. A wide variety of polyols and isocyanates are available for synthesis, and hence we can...
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Application of electronic nose to effectiveness monitoring of air contaminated with toluene vapors biofiltration process
PublicationThe research presents the application of electronic nose (combined with MLR model) to on-line effectiveness monitoring of biofiltration of air contaminated with hydrophobic, odorous compound (toluene vapors). The research was conducted using two-section biotrickling filter inhabited by Candida environmental isolates. Gas chromatography was used as the comparative technique to obtain reliable quantification of toluene concentration...
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Tailoring Graphene to Achieve Negative Poisson's Ratio Properties
PublicationGraphene can be made auxetic through the introduction of vacancy defects. This results in the thinnest negative Poisson's ratio material at ambient conditions known so far, an effect achieved via a nanoscale de-wrinkling mechanism that mimics the behavior at the macroscale exhibited by a crumpled sheet of paper when stretched.
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A Time Delay Controller Included Terminal Sliding Mode and Fuzzy Gain Tuning for Underwater Vehicle-Manipulator Systems
PublicationAn improved Time Delay Control (TDC) method for an Underwater Vehicle-Manipulator System (UVMS) is proposed. The proposed controller consists of three terms: a time-delay-estimation term that cancels nonlinearities of the UVMS dynamics, a Terminal Sliding Mode (TSM) term that provides a fast response and a PID term that reduces the tracking error. In addition the proposed controller uses fuzzy rules to adaptively tune the gains...
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LRIT - a novel system of vessels monitoring for maritime security and safety
PublicationW artykule przedstawiono propozycję architektury przyszłego, globalnego systemu monitorowania statków LRIT (Long Range ship's Identification and Tracking) podlegających konwencji SOLAS. Przedstawiono i scharakteryzowano poszczególne komponenty systemu ze szczególnym uwzględnieniem aspektów radiokomunikacyjnych.
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Ionogel sorbent coatings for determining organophosphorus and pyrethroid insecticides in water and fresh juice samples by headspace-solid phase microextraction
PublicationThe sol–gel method yielded three different ionogel sorbent coatings that were obtained based on a silica material containing ionic liquids (ILs) immobilized in its pores. Two ILs, triethylsulfonium bis(trifluoromethylsulfonyl) imide [Set3][TFSI] and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide [C4C1Pip][TFSI], as well as their equimolar mixture [Set3/C4C1Pip], were used to obtain ionogel fibers. The developed...
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Adaptive acoustic crosstalk cancellation in mobile computer device
PublicationThe cancellation of acoustic crosstalk is employed to enhance the stereo image in mobile listening conditions. A practical setup employing a mobile computer is employed. The adaptation of the crosstalk cancellation filter to the position of the listener's head is featured. The measurement evaluating the possibility of practical application of the method are described. The head and torso simulator was used for measurements. The...
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Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublicationIn this article, specific methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...
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Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublicationIn this study, dedicated methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...