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Search results for: TRICKLING FILTERS
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Square root RC Nyquist filter of fractional delay
PublicationIn this paper we propose a discrete-time FIR (finite impulse response) filter which couples the role of square root Nyquist filter with fractional delay filter. This filter enables to substitute for a cascade of square root RC (SRRC) Nyquist filter and fractional delay filter in one device/algorithm. The aim is to compensate for transmission delay in communication system. Statistically defined performances, e.g. BER (bit error...
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A complex variable fractional-delay FIR filter structure
PublicationW artykule wprowadzamy strukturę zespolonego filtru o skończonej odpowiedzi impulsowej (ang. finite impulse response - FIR) ze zmiennym opóźnieniem ułamkowym (ang. fractional delay - FD). Strukturę tę otrzymujemy na podstawie przestrajanego filtru FD FIR o współczynnikach rzeczywistych. Stanowi ona połączenie zbioru liniowo-fazowych filtrów FIR o współczynnikach stałych rzeczywistych i dwóch łańcuchów mnożąco-akumulujących, zawierających...
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Control of Sensorless Electric Drive with Inverter Output Filter
PublicationW artykule przedstawiono układ sterowanie silnikiem asynchronicznym pracyjący bez pomiaru prędkości obrotowej. Zastosowano nowy rodzaj obserwatora prędkości obrotowej będący połączeniem liniowego obserwatora oraz obserwatora zakłóceń. Jako zakłócenia potraktowano siłę elektromotoryczną indukowaną w silniku. Aby umożliwić poprawną pracę układu z filtrem wyjściowym falownika zastosowano symulator dynamiki filtru do wyznaczenia prądów...
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Tunable Waveguide Filter with Bow-Tie Metallic Posts.
PublicationBadanie i synteza filtru falowodowego zawiewrającego metalowe rezonatory motylkowe (Bow-Tie). Wykorzystano zmodyfikowaną procedurę iteracyjną i metodę dopasowania rodzajów w celu rozwiązania problemu brzegowego na pojedynczej sekcji filtru i określenie pola rozproszonego od rezonatora motylkowego. Obrót i przemieszczenie opisywane struktury w złączu falowodowym umożliwia zmianę odpowiedzi częstotliwościowych układu. Efekt rotacji...
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Dual-Polarized Wideband Bandpass Metasurface-Based Filter
PublicationThis paper presents a novel metasurface-based bandpass filter. The structure is realized by simply patterning a double-sided AD250 substrate, and does not require any vias or insertion of lumped elements. The top layer is an annular- aperture-array with multiple inner conductors, whereas the bottom layer is a first-order Hilbert-curve array. FEM-based simulation results of the filter are obtained using HFSS. The experimental validation...
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In-ADC, Rank-Order Filter for Digital Pixel Sensors
PublicationThis paper presents a new implementation of the rank-order filter, which is established on a parallel-operated array of single-slope (SS) analog-to-digital converters (ADCs). The SS ADCs use an “on-the-ramp processing” technique, i.e., filtration is performed along with analog-to-digital conversion, so the final states of the converters represent a filtered image. A proof-of-concept 64 × 64 array of SS ADCs, integrated with MOS...
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Multistage generalized adaptive notch filter with improved accuracy
PublicationGeneralized adaptive notch filters (GANFs) are estimators of coefficients of quasi-periodically time-varying systems. Current state of the art GANFs can deliver highly accurate estimates of system variations’ frequency, but underperform in terms of accuracy of the coefficient estimates. The paper proposes a novel multistage GANF with accuracy improved in this aspect. The processing pipeline consists of three stages. The preliminary...
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The effect of using jug-type water filters on selected metals concentration in tap water – a case study
PublicationIn this study, the effect of the filtration process on Na, K, Mg, Ca, Fe and Zn concentration in water, using filters from one of the leading European manufacturers, was investigated. The increase in Na (up to 300%) and K concentration (up to 320%) at the beginning of jug filter usage was reported. A decrease in Ca, Fe and Zn concentration was observed. Standard filters remove 80–90% of Mg from tap water at the beginning of the...
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Mosaic Optical Fibers
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Convex universal fixers
PublicationPraca dotyczy dominowania wypukłego w grafach pryzmowych.
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Polyaryletherketone polymer nanocomposite engineered with nanolaminated Ti3SiC2 ceramic fillers
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Nanofillers-containing polymer composite filters Filtracyjne kompozyty polimerowe z dodatkiem nanonape�niaczy
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Influence of Carbon Sorbent Quantity on Breakthrough Time in Absorbent Filters for Antismog Half Mask Application
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Generalized adaptive comb filters/smoothers and their application to the identification of quasi-periodically varying systems and signals
PublicationThe problem of both causal and noncausal identification of linear stochastic systems with quasiharmonically varying parameters is considered. The quasi-harmonic description allows one to model nonsinusoidal quasi-periodic parameter changes. The proposed identification algorithms are called generalized adaptive comb filters/smoothers because in the special signal case they reduce down to adaptive comb algorithms used to enhance...
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A Novel Coupling Matrix Synthesis Technique for Generalized Chebyshev Filters With Resonant Source–Load Connection
PublicationThis paper reports a novel synthesis method for microwave bandpass filters with resonant source–load connection. In effect, a network realizing N+1 transmission zeros (where N is the number of reflection zeros) is obtained. The method is based on a prototype transversal coupling matrix (N+2, N+2) with source and load connected by a resonant circuit formed by a capacitor in parallel with a frequency-invariant susceptance. To complement...
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On designing minimax adjustable wideband fractional delay FIR filters using two-rate approach
PublicationZaprezentowano nowe rozwiązanie problemu projektowania numerycznie oszczędnego, przestrajalnego, szerokopasmowego filtru ułamkowo opóźniającego o skończonej odpowiedzi impulsowej (FIR) w strukturze Farrowa. Innowacja polega na zagregowaniu dwóch podejść. Pierwsze z nich polega na równoczesnej optymalizacji wszystkich podfiltrów struktury Farrowa. Drugie wykorzystuje dwuszybkościową aranżację dwustopniową. Docelowe rozwiązanie jest...
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Low-Loss 3D-Printed Waveguide Filters Based on Deformed Dual-Mode Cavity Resonators
PublicationThis paper introduces a new type of waveguide filter with smooth profile, based on specially designed dual-mode (DM) cavity resonators. The DM cavity design is achieved by applying a shape deformation scheme. The coupling between the two orthogonal cavity modes is implemented by breaking the symmetry of the structure, thus eliminating the need for additional coupling elements. The modes operating in the cavity are carefully analyzed...
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Miniaturized Dual-Band SIW-Based Bandpass Filters Using Open-Loop Ring Resonators
PublicationThis article presents two novel architectures of dual-band substrate integrated waveguide (SIW) bandpass filters (BPFs). Initially, two identical open-loop ring resonators (OLRRs) are coupled face-to-face on the top of the SIW cavity to realize a dual-band single-pole BPF. To obtain two-pole dual-band characteristics, two OLRRs resonant units are assembled horizontally within the top metal layer of the SIW, which is a technique...
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The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures
PublicationSubstances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist,...
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Removal of cyclohexane and ethanol from air in biotrickling filters inoculated with Candida albicans and Candida subhashii
PublicationThis paper presents investigations on the removal of cyclohexane and ethanol from air in polyurethane- -packed biotrickling filters, inoculated with Candida albicans and Candida subhashii fungal species. Results on process performance together with flow cytometry analyses of the biofilm formed over packing elements are presented and discussed. The results indicate that the presence of ethanol enhances the removal efficiency of cyclohexane...
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Compact Quasi-Elliptic-Type Inline Waveguide Bandpass Filters With Nonlinear Frequency-Variant Couplings
PublicationThis work presents the design techniques to synthesize a class of compact inline quasi-elliptic-type waveguide cavity bandpass filters based on novel nonlinear frequency-variant couplings (NFVCs). These highly dispersive frequency-variant couplings (FVCs) are realized by means of a pair of partial-height posts that are placed at the junctions between every two cavity resonators. Each NFVC produces a transmission pole in between...
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Low-Voltage Low-Power Filters with Independent ω0 and Q Tuning for Electronic Cochlea Applications
PublicationAn acoustic second-order low-pass filter is proposed for filter banks emulating the operation of a human cochlea. By using a special filter structure and an innovative quality (Q)-factor tuning technique, an independent change of the cutoff frequency (ω0) and the Q-factor with unchanged gain at low frequencies is achieved in this filter. The techniques applied result in a simple filter design with low Q-factor sensitivity to component...
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Estimation of the angular position of a two-wheeled balancing robot using a real IMU with selected filters
PublicationA low-cost measurement system using filtering of measurements for two-wheeled balancing robot stabilisation purposes has been addressed in this paper. In particular, a measurement system based on gyroscope, accelerometer, and encoder has been considered. The measurements have been corrected for deterministic disturbances and then filtered with Kalman, α-β type, and complementary filters. A quantitative assessment of selected filters...
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Distributed tracking system with central trajectories initialization
PublicationW pracy rozważa się problem wyznaczania trajektorii przy użyciu rozproszonego, wieloczujnikowego systemu. W systemie tego typu trajektoria poruszającego się obiektu wyznaczana jest przez grupę lokalnych estymatorów stanu. Każdy z estymatorów korzysta z filtru Kalmana i danych z pojedynczego źródła w celu określenia trajektorii obiektu. Zwykle źródła danych (czujniki) pracujące na potrzeby estymatorów lokalnych nie obserwują takiego...
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An unorthodox view on the problem of tracking facial expressions
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Multiple frequency tracker with improved tracking Capabilities
PublicationW pracy zaproponowano prostą modyfikację znanego z literatury wieloczęstotliwościowego adaptacyjnego filtra wycinającego, prowadzącą do istotnej poprawy jego charakterystyk nadążania.
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Surveillance camera tracking of GEO positioned objects
PublicationRozdział opisuje system sterowania kamerami ruchomymi PTZ realizujący śledzenie poruszającego się obiektu o znanej pozycji GPS. Przedstawione są idea systemu oraz możliwości jego wykorzystania. Opisane są: procedura kalibracji pola widzenia kamery i sposób powiązania z danymi o lokalizacji, procedura predykcji ruchu w celu kompensacji opóźnień czasowych. Omówiony jest zaimplementowany system modułowy, w którego skład wchodzą: terminale...
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An unorthodox view on the problem of tracking facial expressions
PublicationRecent developments in imaging cameras has opened a new way of analyzing facial expression. We would like to take advantage from this new technology and present a method of imaging and processing images of human face as a response to the particular stimuli. The response in this case is represented by the facial expressions and the stimuli are still images representing six basic emotions according to Eckmann. Working hypothesis...
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An unorthodox view on the problem of tracking facial expressions
PublicationRecent developments in imaging cameras has opened a new way of analyzing facial expression. We would like to take advantage from this new technology and present a method of imaging and processing images of human face as a response to the particular stimuli. The response in this case is represented by the facial expressions and the stimuli are still images representing six basic emotions according to Eckmann. Working hypothesis...
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Tracking of the Multimodal Ordering Process in FePd Alloy
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The sun tracking photovoltaic system in Northern Poland
PublicationPrezentowana fotowoltaiczna instalacja nadążna została umieszczona na dachu budynku Wydziału Chemicznego Politechniki Gdańskiej i składa się z czterech modułów: systemu PV, układu komputerowej kontroli położenia, stacji meteorologicznej, umożliwiającej analizę wpływu warunków atmosferycznych (prędkości i kierunku wiatru, temperatury powietrza, nasłonecznienia) na parametry pracy modułów fotowoltaicznych oraz komputerowego systemu...
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Multimedia interface using head movements tracking
PublicationThe presented solution supports innovative ways of manipulating computer multimedia content, such as: static images, videos and music clips and others that can be browsed subsequently. The system requires a standard web camera that captures images of the user face. The core of the system is formed by a head movement analyzing algorithm that finds a user face and tracks head movements in real time. Head movements are tracked with...
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On optimal tracking of rapidly varying telecommunication channels
PublicationWhen parameters of mobile telecommunication channels change rapidly, classical adaptive filters, such as exponentially weighted least squares algorithms or gradient algorithms, fail to estimate them with sufficient accuracy. In cases like this, one can use identification methods based on explicit models of parameter changes such as the method of basis functions (BF). When prior knowledge about parameter changes is available the...
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Parallel frequency tracking with built-in performance evaluation
PublicationThe problem of estimation of instantaneous frequency of a nonstationary complex sinusoid (cisoid) buried in wideband noise is considered. The proposed approach employs a bank of adaptive notch filters, extended with a nontrivial performance assessment mechanism which automatically chooses the best performing filter in the bank. Additionally, a computationally attractive method of implementing the bank is proposed. The new structure...
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Pose-Configurable Generic Tracking of Elongated Objects
PublicationElongated objects have various shapes and can shift, rotate, change scale, and be rigid or deform by flexing, articulating, and vibrating, with examples as varied as a glass bottle, a robotic arm, a surgical suture, a finger pair, a tram, and a guitar string. This generally makes tracking of poses of elongated objects very challenging. We describe a unified, configurable framework for tracking the pose of elongated objects, which...
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On Bayesian Tracking and Prediction of Radar Cross Section
PublicationWe consider the problem of Bayesian tracking of radar cross section. The adopted observation model employs the gamma family, which covers all Swerling cases in a unified framework. State dynamics are modeled using a nonstationary autoregressive gamma process. The principal component of the proposed solution is a nontrivial gamma approximation, applied during the time update recursion. The superior performance of the proposed approach...
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Eye tracking within near-to-eye display
PublicationIn this paper we investigate the effectiveness of the gaze interaction within near-to-eye display. The practical aspect of the paper is about combining an eye tracker with smart glasses. Presented research is related with the eGlasses project, which is focused on the development of an open platform in the form of multisensory electronic glasses and related interaction methods. One of the implemented interaction methods is the one...
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Implementation of control system and tracking objects in a Quadcopter
PublicationIn this paper, we implement a quadcopter assembly with control and navigation module. The project also includes the design of the control panel for the operator which consists of a set of the micro-controller and the glove equipped with sensors and buttons. The panel has a touch screen which displays current parameters such as vehicle status, including information about orientation and geographical coordinates. The concept of quadcopter...
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Bibliometric approach to tracking the concept of international competitiveness
PublicationThe main aim of paper is to identify the growth pattern in the international competitiveness literature, its core publications and key research domains on the basis of bibliometric data from the years 1945–2015. Citation data is collected from the ISI Web of Science Website, Scopus and Google Scholar, and analysed using HistCite, Pajek and VOSviewer software. Bibliometric indicators, network citation, key-route path methods and...
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Computationally efficient index generation unit using a Bloom filter
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efficient fractional delay hilbert transform filter in the farrow structure
PublicationIn this paper the design and application of a Fractional Delay Hilbert Transform Filter (FDHTF) into an adaptive sub-sample delay estimation between two separated sinusoidal signals is considered. The FDHTF incorporates the functions of Hilbertian and variable fractional delay filtering of the incoming signal simultaneously, in one stage. In traditional approach each of these operations was performed separately. Obtained value...
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Asynchronous motor nonlinear control with inverter output LC filter
PublicationFiltr wyjściowy falownika jest stosowany w napędach elektrycznych prądu przemiennego o regulowanej prędkości w celu wygładzenia przebiegów prądów i napięć zasilających silnik. Zastosowanie filtru utrudnia realizację precyzyjnych metod sterowania silnikami, szczególnie w przypadku napędów bezczujnikowych (tj. bez czujnika prędkości obrotowej wału silnika). Ponieważ, ze względów praktycznych, nie stosuje się pomiarów prądów i napięć...
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Automated microwave planar filter design with generalized Chebyshev characteristics.
PublicationIn this paper a technique of automatization of design of microwave filters with generalized Chebyshev characteristics is presented. A full wave electromagnetic simulator linked with the Matlab computing environment is used to ensure a rigorous numerical analysis while at the same time allowing automatization. To decrease time of optimization and overall design process, the Cauchy interpolation technique was used. An automated design...
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A diplexer design method using an augmented channel filter approach
PublicationContinuous development in RFID andmicrocontrollers technologies gives new possibilities to createsystems that are able to integrate a lot of sensors based ondifferent technologies. This integration brings us closer to realizethe Ubiquitous Network Society vision. However, many problemsmust be addressed before we will benefit from such systems. Inthis paper we describe concept of integrating RFID technologywith other sensors technologies...
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A nearly optimal fractional delay filter design with asymmetric window
PublicationW pracy przedstawiono wyniki badań nad zastosowaniem asymetrycznego okna wyodrębnionego zawczasu z filtru optymalnego. Pokazano, że takie podejście przy zastosowaniu dodatkowej korekcji wzmocnienia filtru zależnej od opóźnienia filtru pozwala na projektowanie filtrów prawie optymalnych. W efekcie zaproponowana metoda łączy prostotę metody okien z jakością porównywalną do jakości filtrów optymalnych. Efektywność zaprezentowanej...
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Predictive control of active filter system with LCL coupling circuit
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Sensorless predictive control of three-phase parallel active filter
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A Special Multi-Pulse Converter with Small Active Power Filter
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FIR Filter Design Using Distributed Maximal Flatness Method
PublicationIn the paper a novel method for filter design based on the distributed maximal flatness method is presented. The proposed approach is based on the method used to design the most common FIR fractional delay filter - the maximally flat filter. The MF filter demonstrates excellent performance but only in a relatively narrow frequency range around zero frequency but its magnitude response is no greater than one. This ,,passiveness”...
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Variable Fractional Delay Filter Design Using a Symmetric Window
PublicationIn this paper a numerically efficient method for designing a nearly optimal variable fractional delay (VFD) filter based on a simple and well-known window method is presented. In the proposed method a single window extracted from the optimal filter with fixed fractional delay (FD) is divided into even and odd part. Subsequently, the odd part is discarded and symmetric even part of the extracted window is used to design a family...