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Wyniki wyszukiwania dla: signal
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Using a square-wave signal for fault diagnosis of analog parts of mixed-signal electronic embedded systems
PublikacjaArtykuł przedstawia nowe podejście do detekcji i lokalizacji pojedynczych katastroficznych i parametrycznych uszkodzeń części analogowych w mieszanych sygnałowo elektronicznych systemach wbudowanych. Podejście składa się z trzech etapów: tworzenia słownika uszkodzeń na podstawie krzywych identyfikacyjnych, etapu pomiarowego w którym układ badany pobudzany jest falą prostokątną generowaną przez mikrokontroler a odpowiedź jest próbkowana...
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Music signal equalization in a changing environment
PublikacjaThe paper presents the concept of an automatic system for music signal correction, considering room frequency response and music genre being played. The proposed algorithm, based on the room frequency response, compensates acoustic conditions surrounding the sound source. Additionally, the compensation process considers the signal content by recognizing music genre. As part of the described research, a series of subjective tests...
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Tools for signal analysis of gas sensors
PublikacjaStatystyki drugiego rzedu oraz jklasyczna analiza widmowa są zwykle stosowane do badania sygnałów losowych o rozkładzie gaussowskim. Są one jednak często nieodpowiednie w przypadku analizy niestacjonarnych sygnałów niegaussowskich. Pewne narzędzia do analizy takich sygnałów sa dostępne w bibliotekach środowiska MATLAB. Zostały one wykorzystane do do analizy fluktuacji sygnałów czujników gazów. W artykule przedstawiono system do...
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FMO1 Is Involved in Excess Light Stress-Induced Signal Transduction and Cell Death Signaling
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An automatic system for identification of random telegraph signal (RTS) noise in noise signals
PublikacjaIn the paper the automatic and universal system for identification of Random Telegraph Signal (RTS) noise as a non-Gaussian component of the inherent noise signal of semiconductor devices is presented. The system for data acquisition and processing is described. Histograms of the instantaneous values of the noise signals are calculated as the basis for analysis of the noise signal to determine the number of local maxima of histograms...
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Analysis of Positioning Error and Its Impact on High Frequency Performance Parameters of Differential Signal Coupler of Differential Signal Coupler
PublikacjaThis paper presents the analysis of the effect of differential signal coupler positioning accuracy on its high frequency performance parameters for contact-less high speed chip-to-chip data transmission on PCB application. Our considerations are continuation of the previous works on differential signal coupler concept, design methodology and analysis for high speed data transmission monitoring presented in [1, 2]. The theoretical...
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Application of Complementary Signals in Built-In Self Testers for Mixed-Signal Embedded Electronic Systems
PublikacjaThis 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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The Use of Wavelet Analysis to Denoising of Electrocardiography Signal
PublikacjaThe electrocardiography examination, due to its accessibility and simplicity, has an important role in diagnostics of the heart ailments. It enables quick detection of various heart defects, undetectable by other kinds of diagnostic tools, so it is very popular. Nevertheless, the measured signal is exposed to a different disturbances. Among them, the electromagnetic interferences, drift of reference electrode and high frequency...
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Comparison of selected electroencephalographic signal classification methods
PublikacjaA variety of methods exists for electroencephalographic (EEG) signals classification. In this paper, we briefly review selected methods developed for such a purpose. First, a short description of the EEG signal characteristics is shown. Then, a comparison between the selected EEG signal classification methods, based on the overview of research studies on this topic, is presented. Examples of methods included in the study are: Artificial...
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Optimal ECG lead for deriving respiratory signal
PublikacjaEDR is an interesting measuring technique that allows an indirect assessment of respiratory activity. This is an alternative solution to direct methods that are based on the measurement of air flow, which require a specialized sensor or even a system. However, due to inter-personal anatomical differences, the optimal ECG lead (placement of the electrodes) ensuring the best EDR signal quality is not fixed. An influence of ECG lead...
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SIMPLY AND LOW COAST ELECTROMYOGRAPHY SIGNAL AMPLIFIER
PublikacjaRecently, there has been a noticeable increase in interest in solu tions utilizing electrical signals accompanying muscle activity. Electromyography (EMG) is a technique for recording, analysis and evaluating the electrical activity produced by striated muscle. Its great popularity is due, among other, to the ability to measure with non-invasive electrodes (calle d as sEMG surface electromyography)....
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A random signal generation method for microcontrollers with DACs
PublikacjaA new method of noise generation based on software implementation of a 7-bit LFSR based on a common polynomial PRBS7 using microcontrollers equipped with internal ADCs and DACs and a microcontroller noise generator structure are proposed in the paper. Two software applications implementing the method: written in ANSI C and based on the LUT technique and written in AVR Assembler are also proposed. In the method the ADC results are...
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A Study on Audio Signal Processed by "Instant Mastering"
PublikacjaAn increasing amount of music produced in home- and project-studios results in development and growth of "automatic mastering services". The presented investigation explores changes introduced to audio signal by various online mastering platforms. A music set consisting of 10 songs produced in small facilities was processed by eight on-line automatic mastering services. Additionally, some laboratory-constructed signals were tested....
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Reconstruction of input signal of sensor with frequency output
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Digital structures for high-speed signal processing
PublikacjaThe work covers several issues of realization of digital structures for pipelined processing of real and complex signals with the use of binary arithmetic and residue arithmetic. Basic rules of performing operations in residue arithmetic are presented along with selected residue number systems for processing of complex signals and computation of convolution. Subsequently, methods of conversion of numbers from weighted systems to...
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Respiratory signal of bathing person - preliminary study
PublikacjaThe scope of this paper is analysis of applicability of modern biomedical acquisition system installed in bathtub towards reception of respiratory signals of bathing person. An analysis of the possibility of such measurement is shown as well as preliminary results.
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General analysis of braodband signal spatial filtration.
PublikacjaPrzedstawiono ogólną metodę wyznaczania charakterystyk kierunkowych filtrów przestrzennych dla hydroakustycznych sygnałów przestrzennych. Omówiono wpływ szerokości widma odbieranych sygnałów na szerokość wiązki i poziom listków bocznych. Pokazano skutki oszczędnych metod filtracji przestrzennej stosowanych przy odbiorze sygnałów wąskopasmowych, gdy odbierane są sygnały szerokopasmowe.
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Digital Processing of Frequency–Pulse Signal in Measurement System
PublikacjaThe work presents the issue of the use of multichannel measurement systems of sensors processing input value to impulse signal frequency. The frequency impulse signal obtained from such sensors is often required to be processed at the same time with a voltage signal which is obtained from other sensors used in the same measurement system. In such case, it is usually necessary to sample the output signals from all sensors in the...
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Reduction of the Velocity Impact on the Magnetic Flux Leakage Signal
PublikacjaThe velocity effect on the magnetic flux leakage (MFL) signal was investigated in this paper. Experiments were performed for velocity of the MFL tool within the range of 0–2 m/s. The velocity was not constant during each measurement to imitate real operational conditions of the MFL tool. Two components of the leakage were measured, i.e. the tangential to the motion direction (x) and the normal to the investigated surface (z). In...
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A study on signal processing methods applied to hearing aids
PublikacjaThis paper presents a short survey on current technology available in hearing aids with a focus on digital signal processing techniques used. First, factors influencing the hearing aid effectiveness are introduced. Then, examples of the present DSP methods and strategies are provided. Also, a description of current limitations of hearing aids and future trends of development are shown. Finally, the notion of computational auditory...
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Efficient signal processing in spectroscopic optical coherence tomography
PublikacjaSpectroscopic optical coherence tomography (SOCT) is an extension of a standard OCT technique, which allows to obtain depth-resolved, spectroscopic information on the examined sample. It can be used as a source of additional contrast in OCT images e.g. by encoding certain features of the light spectrum into the hue of the image pixels. However, SOCT require computation of time-frequency distributions of each OCT A-scan, what is...
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Sleep Apnea Detection by Means of Analyzing Electrocardiographic Signal
PublikacjaObstructive sleep apnea (OSA) is a condition of cyclic, periodic ob-struction (stenosis) of the upper respiratory tract. OSA could be associated with serious cardiovascular problems, such as hypertension, arrhythmias, hearth failure or peripheral vascular disease. Understanding the way of connection between OSA and cardiovascular diseases is important to choose proper treatment strategy. In this paper, we present a method for integrated...
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Analysis of allophones based on audio signal recordings and parameterization
PublikacjaThe aim of this study is to develop an allophonic description of English plosive consonants based on recordings of 600 specially selected words. Allophonic variations addressed in the study may have two sources: positional and contextual. The former one depends on the syllabic or prosodic position in which a particular phoneme occurs. Contextual allophony is conditioned by the local phonetic environment. Co-articulation overlapping...
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Determination of electrode impedance by means of exponential chirp signal
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A Distributed System of Signal Acquisition for Induction Motors Diagnostic
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Investigations of speech signal parameters with regard to articulation influences
PublikacjaW pracy zostało podjęte zagadnienie parametryzacji sygnału mowy w kontekście ekstrakcji cech biometrycznych. Analizowane parametry to parametry cepstralne (cepstrum liniowe i mel-cepstrum, czyli MFCC), parametry liniowej predykcji (LPC) oraz momenty widmowe i parametr F0. Zastosowano analize w krótkich stałych segmentach sygnału z zastosowaniem dużego zakładkowania, tzw. ''implicite segmentation''. Umożliwiło to zaobserwowanie...
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Gait Recognition: A Challenging Task for MEMS Signal Identification
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System of speech signal processing and visualisation for linguistic purposes
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Medley filters - simple tools for efficient signal smoothing
PublikacjaMedley filters are defined as convex combinations of elementary smoothing filters (averaging, median) with different smoothing bandwidths. It is shown that when adaptive weights of such a mixture are evaluated using the recently proposed Bayesian rules, one obtains a tool which often outperforms the state-of-the-art wavelet-based smoothing algorithms. Additionally, unlike wavelet-based procedures, medley filters can easily cope...
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Seabed characterisation using spectral moments of the echo signal
PublikacjaZbadano użyteczność zastosowania momentów spektralnych obwiedni echa w rozpoznawaniu i klasyfikacji dna morskiego. Przeprowadzono obliczenia momentów spektralnych dla około 15000 ech od dna zarejestrowanych w rejonie Bałtyku Południowego i potwierdzono tezę, że wartości tych momentów skorelowane są silnie z typem dna i rodzajem osadów.
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Determination of electrode impedance by means of exponential chirp signal.
PublikacjaPrzedstawiona została nowa metoda pomiaru impedancji elektrodowej. Jako pobudzenie zastosowany został niestacjonarny sygnał napięciowy, którego częstotliwość jest ekspotencjalną funkcją czasu. Zastosowanie zmodyfikowanej któtko-czasowej transformaty Fouriera (STFT) w analizie napięciowego pobudzenia i odpowiedzi prądowej pozwala na otrzymanie widma impedancyjnego.
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Substrate noise-aware floorplanning for mixed-signal SOCs.
PublikacjaOpisano nową metodę projektowania systemów na chipie z uwzglednieniem minimalizacji szumu podłożowego. Optymalizacje rozmieszczenia bloków układowych na chipie uzyskuje się dzieki wykorzystaniu algorytmu ewolucyjnego minimalizującego funkcję celu uwzględniającą poziom szumu podłożowego.
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Uncertainty in measuring the power spectrum density of a random signal
PublikacjaPrzedstawiono sposób oszacowania niepewności wyznaczania gęstości widmowej mocy przebiegu losowego. Przeprowadzono ocenę niepewności estymacji gęstości widmowej mocy biorąc pod uwagę propagację niepewności związanej z rejestracją pojedynczej próbki sygnału w algorytmie cyfrowego przetwarzania sygnału oraz błąd obciążenia estymatora wynikający z zastosowanego modelu matematycznego wielkości wyznaczanej. Wyprowadzono zależności na...
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Procesing the complex signal in the acoustic processor of a sonobuoy system
PublikacjaW artykule przedstawiono metody cyfrowego przetwarzania sygnału kompleksowego w procesorze akustycznym systemu radiohydroboi. Omówiono ogólną postać systemu oraz sygnału kompleksowego. Opisano dwie alternatywne metody przetwarzania sygnału: pierwszą w dziedzinie czasu, drugą w dziedzinie częstotliwości. Zaprezentowano schematy blokowe algorytmów obu sposobów przetwarzania. Omówiono problemy praktycznej realizacji poszczególnych...
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Using wearable device for biomedical signal acquisition and processing
PublikacjaIn this paper we present the research conducted on synchronous measurements of biosignals. The experiment was conducted to evaluate the possibility of estimating vital signs based on eye tracking. Method: The eGlasses platform was used for acquisition of ECG, respiration rate, eye and pupil movement and blood pressure. Data were acquired in three 5 min. intervals during which a subject was performing certain tasks. The signals...
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A low complexity double-talk detector based on the signal envelope
PublikacjaA new algorithm for double-talk detection, intended for use in the acoustic echo canceller for voice communication applications, is proposed. The communication system developed by the authors required the use of a double-talk detection algorithm with low complexity and good accuracy. The authors propose an approach to doubletalk detection based on the signal envelopes. For each of three signals: the far-end speech, the microphone...
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Detection of the First Component of the Received LTE Signal in the OTDoA Method
PublikacjaIn a modern world there is a growing demand for localization services of various kinds. Position estimation can be realized via cellular networks, especially in the currently widely deployed LTE (Long Term Evolution) networks. However, it is not an easy task in harsh propagation conditions which often occur in dense urban environments. Recently, time-methods of terminal localization within the network have been the focus of attention,...
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Digital signal processing applied to the modernization of Polish Navy sonars
PublikacjaThe article presents the equipment and digital signal processing methods used for modernizing the Polish Navy’s sonars. With the rapid advancement of electronic technologies and digital signal processing methods, electronic systems, including sonars, become obsolete very quickly. In the late 1990s a team of researchers of the Department of Marine Electronics Systems, Faculty of Electronics, Telecommunications and Informatics, Gdansk...
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A quasi-2D small-signal MOSFET model - main results
PublikacjaDynamic properties of the MOS transistor under small-signal excitation are determined by kinetic parameters of the carriers injected into the channel, i.e., the low-field mobility, velocity saturation, mobility at the quiescent-point (Q-point), longitudinal electric field in the channel, by dynamic properties of the channel, as well as by an electrical coupling between the perturbed carrier concentration in the channel and the...
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Comparison of the effectiveness of automatic EEG signal class separation algorithms
PublikacjaIn this paper, an algorithm for automatic brain activity class identification of EEG (electroencephalographic) signals is presented. EEG signals are gathered from seventeen subjects performing one of the three tasks: resting, watching a music video and playing a simple logic game. The methodology applied consists of several steps, namely: signal acquisition, signal processing utilizing z-score normalization, parametrization and...
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Design of novel microstrip directional coupler for differential signal decoupling
PublikacjaThis study describes a concept of a novel microstrip directional coupler for differential signal decoupling, which can be used to digital signal overhearing on printed-circuit-boards. The complete design method is proposed with rules given analytically. Considered methodology is suitable for synthesis of couplers with low coupling factors, which have negligible influence on the transmission in main line. Theoretical considerations...
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A quasi-2D small-signal MOSFET model - main results
PublikacjaMain results stemming from a new quasi 2D non-quasi-static small-signal four-terminal model of the MOSFET are presented in this work. The model is experimentally verified up to 30 GHz.
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Influence of sensor design and optical properties of tissue on the photoplethysmographic signal
PublikacjaPhotopletysmography and an associated technique called pulse oximetry are still explored due to the expectations that they give a lot of information about the state of the patient and, also, due to the fact that they are non invasive. Knowledge about the impact of various parameters on the measured signal leads to a faster and a more reliable way of analyzing measurement results and finding the dependencies between the involved...
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Effect of oxygenation time on signal of a sensor based on ionic liquids
PublikacjaThe paper presents an oxygen sensor based on ionic liquids and solid electrodes. The following ionic liquids have been employed: [BMIM][BF4], [HMIM][Cl], [BMIM][N(CN2)]. Minimum time of the sensor exposure to analyte, after which the signal (current intensity) was stable, has been evaluated. An impact of volumetric flow rate of analyte on the sensor exposure time and signal has been determined. A product of permeability coefficient...
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Signal propagation in electromagnetic media described by fractional-order models
PublikacjaIn this paper, signal propagation is analysed in electromagnetic media described by fractional-order (FO) models (FOMs). Maxwell’s equations with FO constitutive relations are introduced in the time domain. Then, their phasor representation is derived for one-dimensional case of the plane wave propagation. With the use of the Fourier transformation, the algorithm for simulation of the non-monochromatic wave propagation is introduced....
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Research on methods for detecting respiratory rate from photoplethysmographic signal
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Analysis of radiometric signal in sedimentating suspension flow in open channel
PublikacjaThe article discusses issues related to the estimation of the sedimentating solid particles average flow velocity in an open channel using radiometric methods. Due to the composition of the compound, which formed water and diatomite, received data have a very weak signal to noise ratio. In the process analysis the known determining of the solid phase transportation time delay the classical cross-correlation function is the most...
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Simulation of Signal Propagation Along Fractional-Order Transmission Lines
PublikacjaIn this paper, the simulation method of signal propagation along fractional-order (FO) transmission lines is presented. Initially, fractional calculus and the model of FO transmission line are introduced. Then, the algorithm allowing for simulation of the nonmonochromatic wave propagation along FO transmission lines is presented. It employs computations in the frequency domain, i.e., an analytical excitation is transformed to the...
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Methods of data extraction from sub-bottom profiler's signal
PublikacjaData obtain during sounding Gdansk Bay with SES-2000 Standard parametric sub-bottom profiler has two types of information: envelope and pure signal. First is used to plot echograms in real time and contain envelope of echo. The second one is stored during sounding and can be processed after recording data. Comparison of results will be shown and discussed. First step in investigation was proper configuration of small measurement...
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Optimization of impedance measurements using ‘chirp’ type perturbation signal
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