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Wyniki wyszukiwania dla: JOHNSON-NOISE
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INFLUENCE OF TEST CONDITIONS ON TYRE/ROAD NOISE MEASURED BY THE DRUM METHOD
PublikacjaTyre/road noise is one of the most important environmental problems related to road traffic. Nowadays a few standard procedures of tyre/road noise measurements are in use. Unfortunately, measurement conditions specified within relevant standards are very different. For example, procedure described in ISO 11819-2 used for pavement investigations requires tyre load of 3200 N and capped inflation pressure of 200 kPa. At the same time...
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Rolling Resistance And Tire/Road Noise on Rubberized Asphalt Pavement In Poland
PublikacjaThe paper presents results of tire/road noise and rolling resistance measurements performed on stone-matrix asphalt (SMA) that contains rubberized asphalt developed and produced by the company in Poland. Bituminous binder was modified with polymer and additive of crumb rubber. First observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger car...
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Three solvers for MIMO noise radar clutter cancellation - a performance comparison
PublikacjaThe problem of canceling strong clutter echos in a MIMO noise radar is considered. Execution times of three algorithms is compared. The first solution is a standard Least Squares approach employing Cholesky decomposition of the transmitted signal sample autocorrelation matrix. The second approach is based on careful waveform design which guarantees that the signal sample autocorrelation matrix has Toeplitz structure. This enables...
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Frequently updated noise threat maps created with use of supercomputing grid
PublikacjaAn innovative supercomputing grid services devoted to noise threat evaluation were presented. The services described in this paper concern two issues, first is related to the noise mapping, while the second one focuses on assessment of the noise dose and its influence on the human hearing system. The discussed services were developed within the PL-Grid Plus Infrastructure which accumulates Polish academic supercomputer centers....
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Certification requirements for tram noise measurements in terms of today’s expectations in cities
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Barkhausen noise properties measured by different methods for deformed Armco samples
PublikacjaPorównano właściwości sygnału napięciowego efektu Barkhausena (BN) uzyskanego za pomocą 'sondy punktowej' (użytecznej dla badań przemysłowych) oraz cewki otaczającej badany materiał. W pierwszej metodzie mierzono trzy wielkości: V1 - napięcie skuteczne, Nc - liczba impulsów, V2 - napięcie kontrolne z cewki. W drugiej metodzie z napięcia indukowanego w cewce wyznaczano pętlę histerezy B(H), obwiednie z napięcia skutecznego a także...
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Rolling resistance and tyre/road noise on rubberised asphalt pavement in Poland
PublikacjaThe paper presents results of tyre/road noise and rolling resistance measurements performed on stone mastics asphalt (SMA) that contains rubberised asphalt, developed and produced by a refinery in Poland. Bituminous binder was modified with polymer and addition of crumb rubber. The first observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger...
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ROSANNE Project: New Procedure for Noise Characterisation of Road Surfaces in Europe
PublikacjaROSANNE is a collaborative project in the 7th EU Framework Programme which aims at harmonising measurement methods for skid resistance, noise emission and rolling resistance of road pavements as a preparation for standardization. The project started in November 2013 and is developing and improving standards in the field of working group CEN/TC 227/WG 5. Regarding the influence of the pavement on the road traffic noise emission,...
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Signal conditioning for examination of shallow-water acoustic noise correlation properties
PublikacjaThe article describes the process of signal conditioning for examination of acoustic noise correlation properties in shallow water. Knowledge of these properties is very important for the design processes of passive and active hydroacoustic systems. This paper focuses on the above issue from the point of view of passive sonar. In sonar systems, signal processing algorithms operate on both useful acoustic signals, and accompanying...
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Tracking of the broadband source of the underwater noise in the very shallow water conditions
PublikacjaThe paper contains the result s, both theoretical and experimental , connected with the tracking of the underwater noise source as small ships, pontoon , diver and so on. The pro blem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is take n into account the detection of the sources that move on the surface of the sea or underwater in shallow...
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Realistic noise-tolerant randomness amplification using finite number of devices
PublikacjaRandomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification...
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On the Handling of Outliers in the GNSS Time Series by Means of the Noise and Probability Analysis
PublikacjaThe data pre-analysis plays a significant role in the noise determination. The most important issue is to find an optimum criterion for outliers removal, since their existence can affect any further analysis. The noises in the GNSS time series are characterized by spectral index and amplitudes that can be determined with a few different methods. In this research, the Maximum Likelihood Estimation (MLE) was used. The noise amplitudes...
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Analysis of the Usefulness of Cheap Audio Recorders for Spectral Measurement of Environmental Noise
PublikacjaEnvironmental noise pollution is nowadays one of the most serious health threats. The impact of noise on the human body depends not only on the sound level but also on its spectral distribution. Reliable measurements of the environmental noise spectrum are often hampered by the very high price of top quality measuring devices. This paper explores the possibility of using much cheaper audio recorders for the frequency analysis....
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Implementation of constant component filter in measurements of random telegraph signal noise
PublikacjaNoise is generated in all semiconductor devices. The intensity of these fluctuations depends on used elements, manufacturing process, operating conditions and device type. The result noise is a superposition of different kinds of fluctuations like thermal noise, generation-recombination noise, 1/f noise, shot noise and Random Telegraph Signal (RTS) noise. The last one, RTS noise is observed as nonstationary impulse fluctuations....
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A review of design approaches for the implementation of low-frequency noise measurement systems
PublikacjaElectronic noise has its roots in the fundamental physical interactions between matter and charged particles, carrying information about the phenomena that occur at the microscopic level. Therefore, Low-Frequency Noise Measurements (LFNM) are a well-established technique for the characterization of electron devices and materials and, compared to other techniques, they offer the advantage of being non-destructive and of providing...
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Investigating Noise Interference on Speech Towards Applying the Lombard Effect Automatically
PublikacjaThe aim of this study is two-fold. First, we perform a series of experiments to examine the interference of different noises on speech processing. For that purpose, we concentrate on the Lombard effect, an involuntary tendency to raise speech level in the presence of background noise. Then, we apply this knowledge to detecting speech with the Lombard effect. This is for preparing a dataset for training a machine learning-based...
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Assessment of Fuel Cells’ State of Health by Low-Frequency Noise Measurements
PublikacjaWe proposed applying low-frequency (flicker) noise in proton-exchange membrane fuel cells under selected loads to assess their state of health. The measurement set-up comprised a precise data acquisition board and was able to record the DC voltage and its random component at the output. The set-up estimated the voltage noise power spectral density at frequencies up to a few hundred mHz. We observed the evolution of the electrical...
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Evaluation of reinforcement corrosion rate in concrete structures by electrochemical noise measurements
PublikacjaW pracy przedstawiono wyniki obliczeń rezystancji polaryzacyjnej w układzie złożonym z dwóch elektrod (ze stali węglowej oraz elektrody odniesienia), umieszczonych w otulinie betonowej. Szybkość korozji ulega zmianom uzależnionym od stopnia nasiąknięcia betonu roztworem zawierającym jony chlorkowe. Zmiany rezystancji polaryzacyjnej elektrody stalowej oceniane są na podstawie pomiarów prądowego i potencjałowego szumu elektrochemicznego....
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Low-frequency noise in ZrS3 van der Waals semiconductor nanoribbons
PublikacjaWe report the results of the investigation of low-frequency electronic noise in ZrS3 van der Waals semiconductor nanoribbons. The test structures were of the back-gated field-effect-transistor type with a normally off n-channel and an on-to-off ratio of up to four orders of magnitude. The current–voltage transfer characteristics revealed significant hysteresis owing to the presence of deep levels. The noise in ZrS3 nanoribbons...
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Creating Dynamic Maps of Noise Threat Using PL-Grid Infrastructure
PublikacjaThe paper presents functionality and operation results of a system for creating dynamic maps of acoustic noise employing the PL-Grid infrastructure extended with a distributed sensor network. The work presented provides a demonstration of the services being prepared within the PLGrid Plus project for measuring, modeling and rendering data related to noise level distribution in city agglomerations. Specific computational environments,...
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Low frequency noise and DLTS as silicon solar cell characterization tools
PublikacjaPraca zawiera wyniki pomiarów DLTS próbek o powierzchni 1 mm2 krzemowych baterii słonecznych wykazujących znaczne niejednorodności wykryte za pomocą metody LBIV (Light Beam Induced Voltage). Wyniki pomiarów charakterystyk stałoprądowych oraz szumowych tych próbek zostały także przedstawione.
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Modeling incipient creep damage effects on Barkhausen noise and magnetoacoustic emission.
PublikacjaZaproponowano model fizyczny opisujący zmiany natężenia efektu Barkhausena i emisji magnetoakustycznej podczas procesu degradacji stali ekploatowanych w przemyśle energetycznym.
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Measurement of noise parameter set in the low frequency range: requirements and instrumentation.
PublikacjaOpisano dwa podstawowe szumowe modele metrologiczne czwórnika: ze źródłami szumów odniesionymi do wejścia i ze zwarciowymi prądami szumów. Parametry szumowe opisujące modele zawierające korelację pomiędzy prądami i/lub napięciami są mierzone przy zastosowaniu metod bezpośrednich i pośrednich. Przedstawiono kilka technik redukcji szumów własnych systemu pomiarowego. Szerzej zaprezentowano dwukanałowy system do pomiaru szumów z komputerowym...
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Noise reduction in audio employing spectral unpredictability measure and neural net.
Publikacjamodelu psychoakustycznym zostały przedyskutowane. Uczący się algorytm decyzjny, działający w opraciu o sztuczną sieć neuronową wykorzystany został w klasyfikacji składowych na pasożytnicze i użyteczne. Przedstawiona została również nowa iteracyjna procedura obliczania progu maskowania. W pracy zawarte zostały wyniki eksperymentów, oraz konkluzje odnoszące się do przedstawionych algorytmów.
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Global Optimization for Recovery of Clipped Signals Corrupted With Poisson-Gaussian Noise
PublikacjaWe study a variational formulation for reconstructing nonlinearly distorted signals corrupted with a Poisson-Gaussian noise. In this situation, the data fidelity term consists of a sum of a weighted least squares term and a logarithmic one. Both of them are precomposed by a nonlinearity, modelling a clipping effect, which is assumed to be rational. A regularization term, being a piecewise rational approximation of the ℓ0 function...
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A system for multitask noisy speech enhancement.
PublikacjaW artykule przedstawiono ogolną charakterystyke opracowanego systemu rejestracji i rekonstrukcji mowy. Artykuł zawiera opis składników systemu, ktory jest oprogramowaniem zawierającym zaawansowane narzędzia służące poprawie zrozumiałości mowy. Zaimplementowane narzędzia systemu umożliwiają wyszukiwanie nagrań dźwiękowych i ich obróbkę przy pomocy zaimplementowanych pluginów. W artykule przedstawione wykorzystane w systemie algorytmy...
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Multitask Noisy Speech Enhancement System
PublikacjaW referacie opisano Wielozadaniowy System Poprawy Jakości Sygnału Mowy. Jest to wyspecjalizowany pakiet oprogramowania przeznaczony do rejestrowania sygnału mowy i do poprawy jego jakości oraz zrozumiałości mowy, przy użyciu zaawansowanych procedur cyfrowego przetwarzania sygnału. Pakiet oprogramowania składa się z programów: Rejestrator, Przeglądarka oraz Rekonstruktor. Oprogramowanie to może być użyte w przypadkach, gdy zrozumiałość...
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Analysis of Lombard speech using parameterization and the objective quality indicators in noise conditions
PublikacjaThe aim of the work is to analyze Lombard speech effect in recordings and then modify the speech signal in order to obtain an increase in the improvement of objective speech quality indicators after mixing the useful signal with noise or with an interfering signal. The modifications made to the signal are based on the characteristics of the Lombard speech, and in particular on the effect of increasing the fundamental frequency...
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An in-depth look at the tire rubber hardness influence on tire/road noise measurements
PublikacjaWhen assessing the acoustic quality of a road pavement with the close-proximity (CPX) or the on-board sound intensity (OBSI) method, the rubber hardness of the reference tire substantially affects the measurement. Practical experience shows that measurement tires can get significantly harder within a single measurement season. This is why one would like to normalize measurements to a reference rubber hardness. The recently published...
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COMPARISON OF NOISE EMISSION OF HCT AND CLASSIC VEHICLE COMBINATIONS FOR TIMBER TRANSPORTATION IN SWEDEN
PublikacjaBy means of a special simulation tool, the noise emission of a high-capacity heavy vehicle (11 axles) was compared to that of a classic heavy vehicle (a truck-dolly-semitrailer with 8 axles). The two cases are designated “Extended vehicle” versus “Classic vehicle” in this study, having total lengths of 34 and 25 m, respectively. The Classic vehicle represents the most common articulated heavy vehicle configuration for transport...
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A Simplified Method of Trend Removal to Determine Noise Observed During a Supercapacitor’s Discharging
PublikacjaIn this paper, new method of trend removal is proposed. This is a simplified method based on Empirical Mode Decomposition (EMD). The method was applied for voltage time series observed during supercapacitor discharging process. It assured the determination of an additive noise component after subtracting the identified trend component. We analyzed voltage time series observed between the terminals of the supercapacitor when discharged...
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the assessment of the noise-induced harmful effects based on the properties of human hearing system
PublikacjaA new way of assessment of noise-induced harmful effects on human hearing system is presented in the paper. The method takes into consideration properties of the human hearing system. The pro-posed method determines the cumulative impact on hearing system produced by the excessive noise. Based on the predicted effects of the noise exposure, the new types of noise indicators were developed. The evaluation of these indicators was...
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Road noise mapping in the city area: measurements compared to model-based estimations
PublikacjaThe paper presents an approach to the verification of noise prediction models in selected localization in the city of Gdansk. The experiments described include a comparison between environmentalmeasurement results performed in the terrain and the noise level prediction results. The NMPB-96 (Nouvelle Méthode de Prévision du Bruit) and Harmonoise models outcomes provide the subject ofthe analysis. The proposed solution of continuous...
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The noise-induced harmful effect assessment based on the properties of the human hearing system
PublikacjaA new way of assessment of noise-induced harmful effects on human hearing system is presented in the paper. The method takes into consideration properties of the human hearing system. The pro-posed method determines the cumulative impact on hearing system produced by the excessive noise. Based on the predicted effects of the noise exposure, the new types of noise indicators were developed. The evaluation of these indicators was...
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Low Frequency Noise Measurement of Reverse Polarized Silicon Carbide Schottky Diodes
PublikacjaW artykule przedstawiono wyniki pomiaró szumów cz. wstecznie spolaryzowanych diod Schottky'ego.
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Estimation of the excitation variances of speech and noise AR-models for enhanced speech coding
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Multimedia System for Environmental Noise Monitoring. [Multimedialny System Monitorowania Hałasu Środowiskowego]
PublikacjaIntroductionNumerous reports relating to noise threats in Poland indicate that they occur commonly. The noise has an enormous impact on the health and life quality of the human beings. Noise pollution in Poland is greater than in others UE countries, moreover it has been increased recently. Taking into account 2002/49/WE directive related to the control and assessment of environmental noise a necessity of monitoring these threats...
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Noise spectral density computation based on finite element model of piezoceramic sensor
PublikacjaThe high sensitivity with wide bandwidth is required for sensor applications in non-destructive testing (NDT). The sensitivity of piezoceramic sensors demands to minimize their noise especially thermal noise, polarisation noise and low frequency 1/f noise,which are the main sources of voltage or current fluctuation in this sort of sensors. For simplicity, only the piezoceramic part of sensor was under study. the theoretical and...
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Resistance noise in tio2-based thin film gas sensors underultraviolet irradiation
PublikacjaBadano możliwości wykorzystania fluktuacji rezystancji w cienkich warstwach TiO2 do wykrywania gazów. Pomiary przeprowadzono, gdy próbka była oświetlona promieniowaniem ultrafioletowym o długości 370nm, w obecności gazu H2S. Stwierdzono, że fluktuacje rezystancji są indukowane promieniowaniem ultrafioletowym i pozwalają na wykrycie obecności H2S w stężeniu do 1.5 ppm.
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ESTIMATION OF NONSTATIONARY HARMONIC SIGNALS AND ITS APPLICATION TO ACTIVE CONTROL OF MRI NOISE
PublikacjaA new adaptive comb filtering algorithm, capable of tracking the fundamental frequency and amplitudes of different frequency components of a nonstationary harmonic signal embedded in white measurement noise, is proposed. Frequency tracking characteristics of the new scheme are studied analytically, proving (under Gaussian assumptions and optimal tuning) its statistical efficiency for quasi-linear frequency changes. Laboratory tests...
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<title>New low noise CCD cameras for Pi-of-the-Sky project</title>
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Determination of magnetisation conditions in a Double-Core Barkhausen Noise measurement set-up
PublikacjaThe magnetic Barkhausen effect is useful forassessing 1D and 2D stress states of ferromagnetic steelobjects. However, its extension to technically importantmaterials, such as duplex anisotropic steels, remains challenging. The determination of magnetisation inside the studied object and the electromagnet for various geometries, materials and magnetisation angles is a key issue.Three-dimensional, dynamic finite element analysis...
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Tyre/road noise measurements on ISO tracks using the modified CPX method
PublikacjaTyre rolling noise test method specified in the UNECE Regulation 117 is directly used in the Tyre Labelling Directive. Noise level specified on EU Tyre Label of each new tyre available on the European market was determined based on vehicle coast-by noise measurements performed on the standard reference road surface proscribed in the ISO 10844:2014. Available data from investigations by the vehicle and tyre industry and results...
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Tyre/road noise measurements on ISO tracks according to the UNECE Regulation 117
PublikacjaWithin the Polish-Norwegian research project ELANORE, a limited Round Robin Test has been performed on 3 ISO tracks in Northern Europe. The basic objective of the project is to improve the EU directive on labelling of tyres for noise and rolling resistance, and this directive is based on the measurement procedures defined in the UN ECE Reg.117. The same test car, test tyres and measurement equipment as well as personnel were used...
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Modeling the effect of electric vehicles on noise levels in the vicinity of rural road sections
PublikacjaNumerous European countries experience a steady increase in the share of electric (EV) and hybrid electric (HEV) vehicles in the traffic stream. These vehicles, often referred to as low- or zero-emission vehicles, significantly reduce air pollution in the road environment. They also have a positive effect on noise levels in city centers and in the surroundings of low-speed roads. Nevertheless, issues related to modeling noise from...
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Probability distribution of flicker noise in AuNPdecorated graphene–Si Schottky barrier diode
PublikacjaWe present results of the probability distribution analysis of flicker noise generated in Au nanoparticle (AuNP) decorated graphene–Si Schottky barrier diodes with and without yellow light illumination (592 nm), close to the localized surface plasmon resonance in the AuNPs (586 nm). The AuNPs occupy imperfections in the single-layer graphene and reduce the flicker noise intensity generated in the graphene layer. The estimated probability...
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Active Control of Highly Autocorrelated Machinery Noise in Multivariate Nonminimum Phase Systems
PublikacjaIn this paper, a novel multivariate active noise control scheme, designed to attenuate disturbances with high autocorrelation characteristics and preserve background signals, is proposed. The algorithm belongs to the class of feedback controllers and, unlike the popular feedforward FX-LMS approach, does not require availability of a reference signal. The proposed approach draws its inspiration from the iterative learning control...
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Experimental study of corrosion in reinforced concrete by acoustic emission and electrochemical noise techniques
PublikacjaTechnika emisji akustycznej jest znaną metodą badań korozji zbrojenia żelbetu. Źródłem aktywności akustycznej są zawsze zjawiska o naturze mechanicznej. Przedstawiono wynik badań akustycznych zbrojonego betonu w warunkach polaryzacji anodowej, przyspieszającej procesy korozyjne. Symultanicznie prowadzona była rejestracja szumu elektrochemicznego. Dla umożliwienia korelacji wyników, uzyskanych obiema technikami, wykonana została...
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Decoding of the FSK signal with noise and distortion with the use of coefficients of the time-frequency transform.
PublikacjaStreszczenie: Przeanalizowano sygnał z modulacją FSK wykorzystując metodę transformacji czasowo-częstotliwościowej różniące się sposobem podziału płaszczyzny TF na atomy: krótko-okresowej transformacji Fouriera, transformacji falkowej i transformacji pakietami falkowymi. Transformacja falkowa zapewnia dobrą lokalizację czasową zakłóceń o wielkiej częstotliwości, podczas gdy transformacja pakietami falkowymi zapewnia dobrą lokalizację...
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Comparing noise levels and audiometric testing results employing it based diagnostic systems.
PublikacjaW referacie przedstawiono Internetowy system przeznaczony do przeprowadzania przesiewowych testów słuchu. Zaprezentowano również system informacyjny przeznaczony do monitorowania hałasu środowiskowego. Obie Internetowe aplikacje mogą być pomocne w zmniejszaniu częstości występowania chorób słuchu powodowanych przez hałas środowiskowy i przemysłowy. Porównano wyniki testów audiometrycznych z pomiarami hałasu na podstawie zawartości...