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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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Positive solutions to second-order differential equations with dependence on the first-order derivative and nonlocal boundary conditions
PublikacjaIn this paper, we consider the existence of positive solutions for second-order differential equations with deviating arguments and nonlocal boundary conditions. By the fixed point theorem due to Avery and Peterson, we provide sufficient conditions under which such boundary value problems have at least three positive solutions. We discuss our problem both for delayed and advanced arguments α and also in the case when α(t)=t, t∈[0,1]....
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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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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 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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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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TIME- AND FREQUENCY-DOMAIN QUASI-2D SMALL-SIGNAL MOSFET MODELS
PublikacjaA novel approach to small-signal MOSFET modeling is presented in this book. As a result, time- and frequency-domain physics-based quasi-2D NQS four-terminal small-signal MOSFET models are proposed. The time-domain model provides the background to a novel DIBL-included quasi‑2D NQS four-terminal frequency-domain small-signal MOSFET model. Parameters and electrical quantities of the frequency-domain model are described by explicit...
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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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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal
PublikacjaThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowbandtransmission. Finally narrowband transmission quality in presence of modified ultrawideband...
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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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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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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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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal
PublikacjaThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowband transmission. Finally narrowband transmission quality in presence of modified ultrawideband...
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Research on methods for detecting respiratory rate from photoplethysmographic signal
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Wideband Signal Generation for Jamming Radio-Controlled Improvised Explosive Devices
PublikacjaThis paper focuses on modelling operation of a wideband jamming signal generator, considering the effects present in real device which influence the shape of transmitted signal’s spectrum. Introduction is followed by a brief overview of AEGIS project, aim of which is to develop a mobile generator of electromagnetic curtain. Next, simulation model is described which includes the factors...
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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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Data Compression in Ultrasonic Network Communication via Sparse Signal Processing
PublikacjaThis document presents the approach of using compressed sensing in signal encoding and information transferring within a guided wave sensor network, comprised of specially designed frequency steerable acoustic transducers (FSATs). Wave propagation in a damaged plate was simulated using commercial FEM-based software COMSOL. Guided waves were excited by means of FSATs, characterized by the special shape of its electrodes, and modeled...
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Dynamic Signal Strength Mapping and Analysis by Means of Mobile Geographic Information System
PublikacjaBluetooth beacons are becoming increasingly popular for various applications such as marketing or indoor navigation. However, designing a proper beacon installation requires knowledge of the possible sources of interference in the target environment. While theoretically beacon signal strength should decay linearly with log distance, on-site measurements usually reveal that noise from objects such as Wi-Fi networks operating in...
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Fast High-Impedance Spectroscopy Method Using SINC Signal Excitation
PublikacjaIn this paper the method of fast impedance spectroscopy of technical objects with high impedance (|Zx| > 1 Gohm) is evaluated by means of simulation and practical experiment. The method is based on excitation of an object with a sinc signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance spectrum is obtained with use of continuous Fourier transform...
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Accuracy analysis of the RSSI BLE SensorTag signal for indoor localization purposes
PublikacjaIn this paper we describe possibility of use the RSSI signal (Radio Signal Strength Indication) from Texas Instruments SensorTag CC2650 for indoor positioning purposes. This idea is not a new but in our opinion it is possible to use SensorTags with Bluetooth LE wireless interface for positioning inside buildings in such applications as people findings in hospitals, senior come care, etc. RSSI is mostly selected as the sensor localization...
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Magnetic field gradient as the most useful signal for detection of flaws using MFL technique
PublikacjaThe magnetic flux leakage (MFL) technique is extensively used for detection of flaws as well as for evaluation of their dimensions in ferromagnetic materials. However, proper analysis of the MFL signal is hindered by the MFL sensor velocity causing distortions of this signal. Traditionally measured components of the MFL signal are particularly sensitive to the scanning velocity. In this paper, an another signal – the gradient of...
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Butyrylcholinesterase signal sequence self-aggregates and enhances amyloid fibril formation in vitro
PublikacjaAlzheimer’s disease (AD) pathogenesis has been attributed to extracellular aggregates of amyloid β (Aβ) plaques and neurofibrillary tangles in the human brain. It has been reported that butyrylcholinesterase (BChE) also accumulates in the brain Aβ plaques in AD. We have previously found that the BChE substitution in 5′UTR caused an in-frame N-terminal extension of 41 amino acids of the BChE signal peptide. The resultant variant...
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Pitch estimation of narrowband-filtered speech signal using instantaneous complex frequency
PublikacjaIn this paper we propose a novel method of pitch estimation, based on instantaneous complex frequency (ICF). New iterative algorithm for analysis of ICF of speech signal in presented. Obtained results are compared with commonly used methods to prove its accuracy and connection between ICF and pitch, particularly for narrowband-filtered speech signal.
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Pitch estimation of narrowband-filtered speech signal using instantaneous complex frequency
PublikacjaIn this paper we propose a novel method of pitch estimation, based on instantaneous complex frequency (ICF). New iterative algorithm for analysis of ICF of speech signal in presented. Obtained results are compared with commonly used methods to prove its accuracy and connection between ICF and pitch, particularly for narrowband-filtered speech signal.
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Value of Perfusion-Weighted MR Imaging in the Assessment of Early Cerebral Alterations in Neurologically Asymptomatic HIV-1-Positive and HCV-Positive Patients
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Radar Signal Parameters Estimation Using Phase Accelerogram in the Time-Frequency Domain
PublikacjaRadar signal parameter estimation, in the context of the reconstruction of the received signal in a passive radar utilizing other radars as a source of illumination, is one of the fundamental steps in the signal processing chain in such a device. The task is also a crucial one in electronic reconnaissance systems, e.g. ELINT (Electronic Intelligence) systems. In order to obtain accurate results it is important to measure, estimate...
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The effect of current signal filtering method on the value of cutting power while sawing wood
PublikacjaThe goal of this work was to investigate an effect of various signal pre-processings on the outline of the electrical power curve and its influence on the measured cutting force estimation. Two signal processing methods were selected for the needs of the experiment, including digital filter and wavelet transform. The filter used was Butterworth, 3rd order band-stop with the cut-out band from 45 Hz to 55 Hz. The second approach...
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Probe signal processing for channel estimation in underwater acoustic communication system
PublikacjaUnderwater acoustic communication channels are characterized by a large variety of propagation conditions. Designing a reliable communication system requires knowledge of the transmission parameters of the channel, namely multipath delay spread, Doppler spread, coherence time, and coherence bandwidth. However, the possibilities of its estimation in a realtime underwater communication system are limited, mainly due to the computational...
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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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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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Geospatial Coverage and Signal Quality Measurements of Terrestrial DAB+ Network in Northern Poland
PublikacjaModern signal coverage maps are prepared based on industry-standard radio propagation models, which take into account a number of parameters, including: type of antenna, distance from the transmitter, type of terrain, etc. However, such simulations are prone to location-specific inaccuracies, and should be verified with in-situ measurements. This paper presents results of a field test of a terrestrial DAB+ (Digital Audio Broadcasting...
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Classifying type of vehicles on the basis of data extracted from audio signal characteristics
PublikacjaThe aim of this study is to find and optimize a feature vector for an automatic recognition of the type of vehicles, extracted form an audio signal. First, the influence of weather-based conditions of road surface on spectral characteristic of the audio signal recorded from a passing vehicle in close proximity to the road is discussed. Next, parameterization of the recorded audio signal is performed. For that purpose, the MIRtoolbox,...
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Signal filtering method of the fast-varying diesel exhaust gas temperature
PublikacjaThe paper presents the problem of the impact of external distortions originating on laboratory test stands on the results of measurements of fast-varying diesel exhaust gas temperature. It has been stressed how significant the aspect of the test stand adaptation is during an experiment to ensure the smallest possible impact. This paper, however, focuses on the methods of mathematical processing of a signal recorded during experimental...
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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 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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Signal Propagation in Electromagnetic Media Modelled by the Two-Sided Fractional Derivative
PublikacjaIn this paper, wave propagation is considered in a medium described by a fractional-order model, which is formulated with the use of the two-sided fractional derivative of Ortigueira and Machado. Although the relation of the derivative to causality is clearly specified in its definition, there is no obvious relation between causality of the derivative and causality of the transfer function induced by this derivative. Hence, causality...
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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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Implementation of an Adaptive Method for Changing the Frequency Division of the Counter Clock Signal in a Frequency-to-Code Converter
PublikacjaProcessing physical quantities into an indirect signal is a standard method of transferring information about the measured quantity to the master system, which analyzes the data obtained from the acquisition system. The intermediate signal is very often the voltage, but another transmission medium can be the frequency of the output signal of the “physical quantity-to-frequency” converter. The article presents the implementation...
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A testing method of analog parts of mixed-signal electronic systems equipped with the IEEE1149.1 test bus
PublikacjaA new solution of the JTAG BIST for testing analog circuits in mixed-signal electronic microsystems controlled by microcontrollers and equipped with the IEEE1149.1 bus is presented. It is based on a new fault diagnosis method in which an analog circuit is stimulated by a buffered signal from the TMS line, and the time response of the circuit to this signal is sampled by the ADC equipped with the JTAG. The method can be used for...
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A concept of Signal Equalization Method Based on Music Genre and the Listener's Room Characteristics
PublikacjaA research study that investigates the influence of the room acoustics environment on the frequency characteristic of the audio signal playback is presented. First, a novel spectral equalization method of the room acoustic conditions is introduced. On the basis of the frequency response of the room, a system for room acoustics compensation based on eight-band equalizer is proposed. The system settings depend on music genre. In...
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Self-optimizing narrowband interference canceller - can reference signal help?
PublikacjaSONIC (Self-Optimizing Narrowband Interference Canceller) is an acronym of the recently proposed active noise control algorithm with interesting adaptivity and robustness properties. SONIC is a purely feedback controller, capable of rejecting nonstationary sinusoidal disturbances (with time-varying amplitudes and/or frequencies) in the presence of plant (secondary path) uncertainties. We show that even though SONIC can work reliably...
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Application of TMS320c67xx signal processors for SONIC-self-optimizing narrowband interference canceler
PublikacjaThe paper presents a laboratory system for testing active control algorithms of acoustics noise in ducts. An applied algorithm - self-optimizing narrowband interference canceller (SONIC), allows one to remove narrowband disturbances of constant or slowly time-varying frequencies. Example experimental results of using the laboratory system for supression of sinusoidal disturbance are described. An electronic part of the system was...
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An idea of an approach to self-testing of mixed signal systems based on a quadratic function stimulation
PublikacjaA new approach to self-testing of the analog parts of mixed-signal electronic systems controlled by microcontrollers equipped with an ADC and a DAC is presented. It is based on a BIST and a new fault diagnosis method. A novelty is the use of the DAC as a component of the BIST, allowing to generate a stimulating signal with a quadratic function shape. It contributes to a better extraction of information about the state of the circuit...
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New Method of Non-Linear Electrochemical Impedance Spectroscopy with an Amplitude-Modulated Perturbation Signal
PublikacjaThe paper presents a new method of non-linear electrochemical impedance spectroscopy (NLEIS), which allows fast and nondestructive evaluation of the corrosion rate and determination of the Tafel coefficients values for a corrosion system under investigation. This method employs amplitude modulation of the ac perturbation signal. The study demonstrated that it was possible to obtain impedance characteristic as a function of the...
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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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Estimation of the amplitude of the signal for the active optical gesture sensor with sparse detectors
PublikacjaIn this paper we deal with the problem of precise gesture recognition for the active optical proximity sensor with sparse 8 photodiodes. We particularly focus on developing the method of estimating the real, usually not observable, maximum signal value representing maximum intensity of light reflected from an obstacle present in the front of the sensor. Different configurations of the fingers were used as an obstacle. The Monte Carlo...
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Study of probe signal bandwidth influence on estimation of coherence bandwidth for underwater acoustic communication channel
PublikacjaA signal transmitted in a shallow Underwater Acoustic Communication (UAC) channel suffers from time dispersion due to the multipath propagation and the refraction phenomena. This causes intersymbol interference of the received signal and frequency-selective fading observed in its spectrum. Coherence bandwidth is one of the key transmission parameters used for designing the physical layer of a data transmission system to minimise...
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Investigation on accelerated impedance spectrum measurement method with multisine signal stimulation
PublikacjaThe paper presents an investigation on the accelerated impedance spectrum measurement method, oriented at parameter identification of technical objects modelled by a linear equivalent circuit, e.g. anticorrosion coatings.The method is based on multisine signal stimulation of an object and response analysis by triangle window filterbanks.It has several advantages, as compared with conventional point-by-point spectrum measurement....