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Wyniki wyszukiwania dla: IMPULSE NOISE
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The analysis of stationary electrochemical noise.
PublikacjaSzum elektrochemiczny jest techniką cieszącą się rosnącym zainteresowaniem. Jedną z podstawowych charakterystyk przebiegów otrzymywanych za pomocą omawianej metody jest widmowa gęstość mocy. Prawidłowa estymacja powyższej wielkości wiąże się z koniecznością zachowania wymogu stacjonarności szumu elektrochemicznego. W niniejszej pracy autorzy proponują zastosowanie rozkładu Wignera-Villego do oceny stopnia niestacjonarności przebiegów...
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Noise of optoelectronic coupled devices.
PublikacjaOpisano trzy systemy do pomiaru szumów transoptora a mianowicie: system do pomiaru szumów m. cz. diod LED, system do pomiaru szumów m. cz. fototranzystorów oraz system do pomiaru szumów m. cz. transoptorów. Przedstawiono wyniki pomiaru szumów m. cz. próby 13 transoptorów. Określono współczynnik korelacji między intensywnością szumów a wybranymi parametrami stałoprądowymi tych transoptorów.
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Noise of optoelectronic coupled devices.
PublikacjaOpisano dwa systemy do pomiaru szumów transoptorów. System do pomiaru szumów fototranzystora oraz system do pomiaru szumów transoptora. Przedstawiono porównanie wyników pomiarów szumów 27 transoptorów trzech różnych producentów.
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Noise in biological Raman spectroscopy
PublikacjaRaman spectroscopy is a widely used method to investigate chemical molecules by analyzing their vibrational transitions. It utilizes inelastic scattering of the laser light irradiating the investigated object. The scattered light requires appropriate filtering to reduce dominant laser light and expose much weaker components having shifted wavelengths of a characteristic spectral pattern. These components are measured by dispersing...
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Model of noise sources in supercapacitors
PublikacjaThe paper presents detailed model of noise sources in supercapacitors. Noise phenomena observed in supercapacitors may be used as a diagnostic tool for assessment of supercapacitor quality or degradation mechanisms (e.g. corrosion of the electrodes or cloggin g up the pores) during ageing. Therefore, it is important to consider where noise is generated. The equivalent circuit of noise sources existing...
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A complex evaluation of lightning protection earthings using the impulse testing method
PublikacjaW artykule zamieszczono opis nowej procedury pomiaru uziemień odgromowych metodą udarową. Zgodnie z propozycję podczas testu udarowego można pomierzyć nie tylko impedancję udarową uziemienia, ale także ocenić jego rezystancję oraz współczynnik udaru. Wynik takiego badania uwzględnia tylko tę część uziomu, którą określa się jako jego długość efektywną.
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Finding the protection of lighting grounding with estimating its impulse impedance componets
PublikacjaOmówiono metodę rozdzielania składowych impedancji udarowej uziemień. Podano wskazania dotyczące oceny jakości ochrony odgromowej na podstawie wartości składowych impedancji udarowej.
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New method of IEEE 802.15.4a UWB Impulse Radio Spectrum Shaping
PublikacjaThis paper presents a new technique of IEEE 802.15.4a ultra-wideband signal spectrum control, based on changes in sequences of transmitted pulses with very short duration time. Basic parameters of UWB signal and outline of proposed spectrum shaping methods are briefly described. The main part of the paper presents influence of signal and algorithms parameters on the results of spectrum shaping.
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Earthing effective length for low and high amplitudes of lightning impulse currents
PublikacjaUziemienia w systemie elektroenergetycznym mogą być bardzo rozległe, zwłaszcza ze względu powszechne stosowanie połączeń ekwipotencjalizacyjnych. Ocena tak rozległych systemów z punktu widzenia ich przydatności do celów ochrony odgromowej jest dość trudna, ponieważ tylko część takiego rozległego systemu bierze udział w rozpraszaniu prądu piorunowego w gruncie. Ta część uziomu jest nazywana jego długością efektywną. W pracy zamieszczono...
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Channel Impulse Response Measurements at mmWave Band in Office and Conference Rooms
PublikacjaIn this paper, the measurements of the channel impulse response at mmWave band in office and conference rooms are described. The central frequency is 27 GHz with a bandwidth of 400 MHz. The description of the used measurement stand and considered environments are presented. The initial analysis of the power delay profile, mean delay, and RMS delay spread allows preliminary conclusions to be drawn that there is a significant impact...
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Measurement of Impulse Response of Shallow Water Communication Channel by Correlation Method
PublikacjaPerformances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel; conditions that can additionally change in time due to the movement of the acoustic system transmitter and receiver or to reflection by underwater objects of the transmitted signal. The time-varying impulse response is a comprehensive description of dynamically changing transmission...
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Developing assumptions for the tram noise attenuation passive system using the noise maps analysis method
PublikacjaThe paper presents experimental research carried out to determine the possible actions to reduce thenoise generated by trams in a highly urbanised area. A few design strategies affecting tram ride qualityhave been presented – especially in the aspect of the acoustic phenomena. Main sources of the noisein trams were characterised. The paper includes selected results of comprehensive...
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The Application Of A Noise Mapping Tool Deployed In Grid Infrastructure For Creating Noise Maps Of Urban Areas
PublikacjaThe concept and implementation of the system for creating dynamic noise maps in PL-Grid infrastructure are presented. The methodology of dynamic acoustical maps creating is introduced. The concept of noise mapping, based on noise source and propagation models, was developed and employed in the system. The details of incorporation of the system to the PL-Grid infrastructure are presented. The results of simulations performed by...
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Issues related to noise and protection against noise against the background of hazards present in the working environment
PublikacjaNoise is one of the physical factors that poses the greatest threat in the working environment. In order to reduce the noise exposure, noise reduction at the source should be considered. Next, the engineering and administrative controls are being developed. Finally, hearing protectors are used. Issues related to protection against noise are part of the topics in the field of occupational...
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Iterative learning approach to active noise control of highly autocorrelated signals with applications to machinery noise
PublikacjaThis paper discusses the design and application of iterative learning control (ILC) and repetitive control (RC) for high modal density systems. Typical examples of these systems are structural and acoustical systems considered in active structural acoustic control (ASAC) and active noise control (ANC) applications. The application of traditional ILC and RC design techniques, which are based on a parametric system model, on systems...
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The influence of switching impulses on degradation of polyethylene insulation
PublikacjaW pracy omówiono czas inkubacji i wzrostu drzewka elektrycznego rozwijającego się w izolacji polietylenowej usieciowanej w układzie ostrze - płyta uziemiona. Badania przeprowadzono przy udarach łączeniowych nałożonych na napiecie przemienne (napięcie skojarzone). Wyniki badań wskazują na istotny wpływ ładunku przestrzennego wprowadzanego napięciem udarowym na inkubację i propagację drzewienia elektrycznego.
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The EU Tyre Noise Label: The problem with measuring the noise level of only a few of all tyre variants
PublikacjaThe STEER project, described in another Inter-Noise 2022 paper, has evaluated the performance of the noise label of the European tyre label. The major finding was that uncertainties of the tyre/road noise measurements were higher than should be accepted. One of the worst uncertainty sources was found to be the common practice to measure only some tyres of all sizes or variants within a tyre line, to save money. Generally, only...
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EVALUATION OF SOUND QUALITY FEATURES ON ENVIRONMENTAL NOISE EFFECTS – A CASE STUDY APPLIED TO ROAD TRAFFIC NOISE
PublikacjaThe paper shows a study on the relationship between noise measures and sound quality (SQ) features that are related to annoyance caused by the traffic noise. First, a methodology to perform analyses related to the traffic noise annoyance is described including references to parameters of the assessment of road noise sources. Next, the measurement setup, location and results are presented along with the derived sound quality features....
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Identification of Optocoupler Devices with RTS Noise
PublikacjaThe results of noise measurements in low frequency range for CNY 17 type optocouplers are presented. The research were carried out on devices with different values of Current Transfer Ratio (CTR). The methods for identification of Random Telegraph Signal (RTS) in noise signal of optocouplers were proposed. It was found that the Noise Scattering Pattern method (NSP method) enables to identify RTS noise as non-Gaussian component...
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A new methof for identyfication of RTS noise
PublikacjaIn the paper a new method, called the Noise Scattering Pattern (NSP) method, for RTS noise identyfication in a noise signal is presented. Examples of patterns of the NSP method are included.
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The Low-frequency Noise of SiC MESFETs
PublikacjaPrzedstawiono system do pomiaru szumów małoczestotliwościowych tranzystorów SiC MESFET oraz przykładowe wyniki pomiarów.
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Novel applications of noise in sensing and communications
PublikacjaPrzedstawiono zaproponowane w ostatnich latach sposoby wykorzystania szumów do wykrywania gazów, jako źródła informacji o atmosferze otaczającej czujnik. Ponadto, przedstawiono możliwości wykorzystania zjawisk losowych do bezpiecznej komunikacji.
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Analysis of noise properties of the optocoupler device
PublikacjaIn the paper the localization of a source of Random Telegraph Signal noise (RTS noise) in optocoupler devices type CNY 17 were defined. The equivalent noise circuit in low frequency noise for these type optocouplers was proposed.
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RTS Noise in Optoelectronic Coupled Devices
PublikacjaPrzedstawiono wyniki pomiarów szumów z zakresu małuch częstotliwości transoptorów typu CNY17. Pomiary wykonano w systemie zaprojektowanym i skonstruowanym przez Autorów. Stwierdzono występowanie szumów RTS w kilku egzemplarzach badanej próby transoptorów. Przeprowadzono analizę szumów RTS, zarówno w dziedzinie czasu, jak i w dziedzinie częstotliwości. Oszacowano wartość częstotliwości, przy której występują szumy wybuchowe, na...
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Intelligent system for environmental noise monitoring.
PublikacjaW rozdziale przedstawiono projekt i realizację automatycznej stacji monitorowania hałasu środowiskowego. Stanowi ona jeden z elementów tworzonego w Katedrze Systemów Multimedialnych Politechniki Gdańskiej Multimedialnego Systemu Monitorowania Hałasu. Przedstawiono ogólną budowę stacji pomiarowej oraz omówiono jej podstawową funkcjonalność. Obszerniej opisano dodatkowe możliwości stacji, do których należą: komunikacja z wykorzystaniem...
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universal system for diagnosing environmental noise.
PublikacjaW publikacji przedstawiono projekt multimedialnego systemu komputerowego do monitoringu hałasu środowiskowego. Opracowywany system jest powiązany z aktualnie realizowanym w Katedrze Inżynierii Dźwięku i Obrazu Politechniki Gdańskiej projektem, którego celem jest redukcja częstości występowania niedosłuchu. Niedosłuch często jest wywołany przez nadmierny hałas przemysłowy, komunikacyjny lub innego rodzaju niepożądane dźwięki, towarzyszące...
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The stationarity characteristics of electrochemical current noise
PublikacjaPrzedstawiono rezultaty analizy szumu elektrochemicznego generowanego podczas korozji stali 0H18N9 w roztworze 0.1 M H2SO4+0,006 M Cl-. Rejestry uzyskano w warunkach potencjostatycznych. W szumie zaobserwowano trendy i sygnały przejściowe, charakterystyczne dla korozji wżerowej. Trend został usunięty za pomocą aproksymacji wielomianem trzeciego stopnia. Analiza statystyczna wykazała niestacjonarny bądź słabo stacjonarny charakter...
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Tyre/road noise. Reference book.
PublikacjaKsiążka przedstawia zagadnienia związane z hałasem opon samochodowych poruszających się po nawierzchniach drogowych. Zawiera rozdziały poświęcone budowie opon, budowie nawierzchni drogowych, akustyce, mechanizmom generowania hałasu, wpływie czynników eksploatacyjnych i konstrukcyjnych na hałas opon, metodom pomiarowym, modelowaniu, metodom ograniczania hałasu opon, zagadnieniom prawnym i normalizacyjnym. Jest kompletnym przewodnikiem...
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Problems of Railway Noise-A Case Study
PublikacjaUnder Directive 2002/49/EC relating to the assessment and management of environmental noise, all European countries are obliged to model their environmental noise levels in heavily populated areas. Some countries have their own national method, to predict noise but most have not created one yet. The recommendation for countries that do not have their own model is to use an interim method. The Dutch SRM II scheme is suggested for...
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Problems of Railway Noise—A Case Study
PublikacjaUnder Directive 2002/49/EC relating to the assessment and management of environmental noise, all European countries are obliged to model their environmental noise levels in heavily populated areas. Some countries have their own national method, to predict noise but most have not created one yet. The recommendation for countries that do not have their own model is to use an interim method....
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Noise emitted by SKM Trains in Gdansk
PublikacjaHigh intensity traffic of SKM trains in Gdansk carries a significant level of noise emission. SKM line runs through the central part of the city and therefore in the vicinity of residential areas and recreational facilities. This research was planned and performed to find out what was the real noise emission of SKM trains and to determine whether the measurement noise values are within allowed limits. Individual acoustic events...
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Poroelastic Low Noise Road Surfaces
PublikacjaNoise is one of the most important problems related to road traffic. During the last decades, noise emitted by engine and powertrain of vehicles was greatly reduced and tyres became a clearly dominant noise source. The paper describes the concept of low noise poroelastic road surfaces that are composed with mineral and rubber aggregate bound by polyurethane resin. Those surfaces have a porous structure and are much more flexible...
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Final report on noise and rolling resistance
PublikacjaWork Package 6 deals with environmental impacts of PERS use, including noise and rolling resistance. This report covers preliminary noise tests performed in the laboratory and at the road test sites. The obtained results indicate that PERS material reduce noise considerably - up to 12 dB in comparison to SMA16 reference surface. Noise reduction properties are especially visible in the case of factory produced PERS slabs supplied...
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Application of autoencoder to traffic noise analysis
PublikacjaThe aim of an autoencoder neural network is to transform the input data into a lower-dimensional code and then to reconstruct the output from this code representation. Applications of autoencoders to classifying sound events in the road traffic have not been found in the literature. The presented research aims to determine whether such an unsupervised learning method may be used for deploying classification algorithms applied to...
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HOW EFFICIENT IS NOISE LABELING OF TIRES?
PublikacjaSince 2012 all new tires in Europe must be labeled. The label contains general information about tire performance concerning rolling resistance (that corresponds to fuel economy), noise emission and wet grip (only for passenger car tires). Measurements of noise performance of tires must be performed according to the Annex 3 of the Regulation No 117 of the Economic Commission for Europe of the United Nations. The regulation specifies...
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Study of Noise Propagation for Small Vessels
PublikacjaThe paper presents the results of the noise propagation analysis in ship structures tested in a number of AHTS (Anchor Handling Tug Supply) vessels. Statistical Energy Analysis (SEA) based on numerical model developed specially for the purpose of this numerical investigation were conducted. This numerical model enabled the analysis of both the structural elements and the acoustic spaces. For the detailed studies 47 points fixed...
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Numerical and experimental propeller noise investigations
PublikacjaThe standard propeller has been investigated in model scale, using medium size cavitation tunnel. The hydroacoustic characteristics of propellers under different loading conditions have been investigated. Additionally the presented experimental results have been used for the verification of applied numerical approach. During both numerical and experimental analyses non-uniform inflow propeller’s conditions have been adapted. Good...
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Noise related to gas bottles explosions
PublikacjaModern industrialized world is in a never ending danger of accidents and catastrophes of technical nature. Some of them may involve fires and explosions of gas storage bottles or containers. Technical University of Gdansk, Poland performed numerous tests where bottles containing acetylene, oxygen, hydrogen, CO2, LPG, LNG or CNG were blown due to excessive temperature caused by fire. Although those experiments were not focused on...
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Measurements of flicker noise in supercapacitor cells
PublikacjaFlicker noise (1/f-like noise) is often used to assess the quality of various materials and devices. This phenomenon has been observed in different electrochemical devices or reactions (e.g., smart windows, pitting corrosion events). In our exploratory studies we consider how to measure and utilize 1/f noise for the quality assessment of supercapacitors. This task requires special attention because of enormous capacitance of the...
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Application of Maximum-Length Sequences to impulse response measurement of hydroacoustic communications systems
PublikacjaThere is a growing interest in digital transmission of telemetry data on ultrasonic waves. The dependence of signal attenuation on squared frequency, specific to the hy-droacoustic systems, induces problems that do not exist in monochromatic, narrowband radio communications systems. For adapting the transmission parameters to current propagation conditions, a precise knowledge of instantaneous changes of channel performances is...
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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a Impulse Radio Interference
PublikacjaThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. IEEE 802.15.4a UWB signal is being used as interferer, also with frame structure modifications which lead to change spectrum of the interference. Equations and coefficients which allow to calculate ratio between power of useful and interference signal are also presented.
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Hysteresis curves and loops for harmonic and impulse perturbations in some non-equilibrium gases
PublikacjaEvolution of sound in a relaxing gas whose properties vary in the course of wave propagation, is studied. A relaxing medium may reveal normal acoustic properties or be acoustically active. In the first case, losses in acoustic energy lead to an increase in internal energy of a gas similarly as it happens in Newtonian fluids. In the second case, acoustic energy increases in the course of sound propagation, and the internal energy...
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Extended duration running and impulse loading characteristics of an acoustic bearing with enhanced geometry
PublikacjaThis paper presents performance during prolonged running of the acoustic bearing when PZTs are switched off and when they are switched on. The effect of active PZT on shaft’s displacements in X and Y directions is clearly demonstrated. Performance of the acoustic bearing was also assessed when an impulse force was applied to the running shaft at speed. Once again the benefits of having PZTs active are beyond doubt. The instability...
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High frequency impulse ground penetrating radar application in assessment of interlayer connections
PublikacjaGround Penetrating Radar (GPR) technique is commonly used in the nondestructive evaluation of pavement structures. In particular, this method is used to estimate thicknesses of pavement layers as well as it can be utilized in advanced studies of pavement structures. The device presented in this paper comprise the high frequency impulse antennas that allow for investigating the interlayer zones in terms of their electromagnetic...
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ADAPTIVE IDENTIFICATION OF TIME-VARYING IMPULSE RESPONSE OF UNDERWATER ACOUSTIC COMMUNICATION CHANNEL
PublikacjaThe transmission properties of underwater acoustic communication channel can change dynamically due to the movement of acoustic system transmitter and receiver or underwater objects reflecting transmitted signal. The time-varying impulse response measurement and estimation are necessary to match the physical layer of data transmission to instantaneous channel propagation conditions. Using the correlative measurement method, impulse...
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Robert Bogdanowicz dr hab. inż.
OsobyRobert Bogdanowicz received his Ph.D. degree with honours in Electronics from the Gdansk University of Technology. He worked as a post-doc researcher in Ernst-Moritz-Arndt-Universität Greifswald Institut für Physik. He has initiated optical emission imaging of muti-magnetron pulsed plasma and contributed to the development of antibacterial implant coatings deposited by high-power impulse magnetron sputtering. He moved back to...
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IEEE Pulse
Czasopisma -
Inhomogeneity of low-noise wearing courses evaluated by tire/road noise measurements using the close-proximity method
PublikacjaPerforming numerous analyses of tire/road noise measurements on low-noise pavements during the last several years, the authors observed significant inhomogeneity of the wearing course in numerous cases, while similar problems were almost non-existent when dense pavements were measured. Three main causes of low-noise pavement inhomogeneity can be defined. The first one is imperfections in the technology used for asphalt mix production...
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The current amplifier in low frequency noise measurements; Absolute calibration and rigorous 1/f noise extraction for MOSFET´s
PublikacjaPrzedstawiono budowę wzmacniacza prądowego i sposób obliczania szumów wyjściowych przy dołączonym do wejścia rezystorze wzorcowym. Przedstawiono wyniki eksperymentów potwierdzających prawidłowość przyjętego sposobu postępowania. Zaproponowano metodę wyznaczania składowej 1/f szumów drenu tranzystora MOSFET.
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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....