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Wyniki wyszukiwania dla: SIGNAL GENERATION MECHANISM
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Low-coherence sensors with nanolayers for biomedical sensing
PublikacjaIn this paper, we describe the fiber optic low-coherence sensors using thin film. We investigated their metrological parameters. Presented sensors were made with the use of standard telecommunication single mode optical fiber (SMF28). Different materials were applied to obtain thick layers, such as boron doped diamond, silver and gold. The thickness of layers used in the experiments ranged from 100 nm to 300 nm. Measurements were...
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Approximate Cramér–Rao bound on Doppler error in correlation-processing relatively narrowband noise radar
PublikacjaThe paper studies limitations on accuracy of Doppler estimation in continuous-wave noise radar with correlation processing. Second order properties of output of the correlation receiver are evaluated and an approximate Cram´er-Rao bound on errors of Doppler measurement is derived. The accuracy of Doppler measurements is found to be affected by the following factors: power spectral density of noise signal, frequency response of the...
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Microseismic Monitoring of Hydraulic Fracturing - Data Interpretation Methodology With an Example from Pomerania
PublikacjaMicroseismic monitoring is a method for localizing fractures induced by hydraulic fracturing in search for shell gas. The data is collected from an array of geophones deployed on the surface or underground. Ground vibrations are recorded and analysed for fracture location, magnitude and breakage mechanism. For successful microseismic monitoring one need a velocity model of underlying formations. The model is further tuned with...
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Effect of electrode resistance on admittance spectra of planar organic device carrying SCLC and on charge carrier mobility extracted from susceptance
PublikacjaThe work presents small signal admittance spectra of a sandwich system with thin organic layer carrying a space charge limited current. The effect of series resistance of electrodes on the spectra is discussed. Spectra of small signal capacitance are added to get more detailed insight. The analysis performed shows that the series resistance can affect both parts of small signal response within a whole range of frequency. Moreover,...
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Traffic Modeling in IMS-based NGN Networks
PublikacjaIn the modern world the need for accurate and quickly delivered information is becoming more and more essential. In order to fulfill these requirements, next generation telecommunication networks should be fast introduced and correctly dimensioned. For this reason proper traffic models must be identified, which is the subject of this paper. In the paper standardization of IMS (IP Multimedia Subsystem) concept and IMS-based NGN...
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Elimination of impulsive disturbances from archive audio files – comparison of three noise pulse detection schemes
PublikacjaThe problem of elimination of impulsive disturbances (such as clicks, pops, ticks, crackles, and record scratches) from archive audio recordings is considered and solved using autoregressive modeling. Three classical noise pulse detection schemes are examined and compared: the approach based on open-loop multi-step-ahead signal prediction, the approach based on decision-feedback signal prediction, and the double threshold approach,...
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Improved method for real-time speech stretching
Publikacjan algorithm for real-time speech stretching is presented. It was designed to modify input signal dependently on its content and on its relation with the historical input data. The proposed algorithm is a combination of speech signal analysis algorithms, i.e. voice, vowels/consonants, stuttering detection and SOLA (Synchronous-Overlap-and-Add) based speech stretching algorithm. This approach enables stretching input speech signal...
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The accuracy of a new approach to order determination for the Modified Prony method in swath mapping application
PublikacjaThis article presents the performance of a new approach to determine the model order for the modified Prony method applied to swath acoustic mapping. Key requirements for any mapping application are depth determination accuracy and angular resolution. Depth determination accuracy is strictly related to angular accuracy and geometrical relations between receiver and sources of the backscattered signal. Angular resolution determines...
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Analysis of the possibility of creep damage detection in T24 heat resistant steel with the help of magnetic nondestestructive testing methods
PublikacjaThe paper presents the result of an analysis of applicability of various electromagnetic methods of nondestructive evaluation for creep damage detection in a novel heat resistant steel - T24 grade. Two sample sets, cut out from membrane wall tubes, were investigated – the as-delivered one and another exploited for 36,000 h in a power plant. There are described results of magnetic hysteresis loops B(H), Barkhausen noise (BN) and...
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Metoda i algorytmy modyfikacji sygnału do celu wspomagania rozumienia mowy przez osoby z pogorszoną rozdzielczością czasową słuchu
PublikacjaPrzedmiotem badań przeprowadzonych w ramach rozprawy są metody modyfikacji czasu trwania sygnału (ang. Time Scale Modification –TSM) mowy operujące w czasie rzeczywistym oraz ocena ich wpływu na rozumienie wypowiedzi przez osoby z pogorszoną rozdzielczością czasową słuchu. Pogorszona rozdzielczość słuchu jest jednym z symptomów związanych z ośrodkowymi zaburzeniami słuchu (ang. Cetnral Auditory Processing Disorder – CAPD). W odróżnieniu...
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Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublikacjaThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...
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Usage of concentrated spectrogram for analysis of acoustical signals
PublikacjaA novel precise method of signal analysis in the time-frequency domain is presented. A signal energy distribution is estimated by discard and displacement of energy parts of the classical spectrogram. A channelized instantaneous frequency and a local group delay are used in order to energy replacement. Additionally, newly introduced representations such as: a channelized instantaneous bandwidth and a local group duration are used...
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Effect of shallow traps on admittance spectra of the system carrying SCLC and on values of charge carrier mobility extracted from susceptance
PublikacjaThe work concerns small-signal spectra of space-charge-limited current below threshold frequency (ft) of shallow traps. It is shown that below ft the small-signal concentration of trapped charge carriers is proportional to and in phase with small-signal concentration of free charge carriers, so there is no room for “slow shallow traps”. Conductance can be reduced by the traps, however no change in the range of real capacitance...
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Morphology, Photocatalytic and Antimicrobial Properties of TiO2 Modified with Mono- and Bimetallic Copper, Platinum and Silver Nanoparticles
PublikacjaNoble metal nanoparticles (NMNPs) enhanced TiO2 response and extended its activity under visible light. Photocatalytic activity of TiO2 modified with noble metal nanoparticles strongly depends on the physicochemical properties of NMNPs. Among others, the differences in the size of NMNPs seems to be one of the most important factors. In this view, the effect of the metal’s nanoparticles size, type and amount on TiO2 photocatalytic...
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Decomposition of halogenated nucleobases by surface plasmon resonance excitation of gold nanoparticles
PublikacjaHalogenated uracil derivatives are of great interest in modern cancer therapy, either as chemotherapeutics or radiosensitisers depending on their halogen atom. This work applies UV-Vis spectroscopy to study the radiation damage of uracil, 5-bromouracil and 5- uorouracil dissolved in water in the presence of gold nanoparticles upon irradiation with an Nd:YAG ns-pulsed laser operating at 532nm at dierent uences. Gold nanoparticles...
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TiO2 nanotube arrays-based reactor for photocatalytic oxidation of parabens mixtures in ultrapure water: Effects of photocatalyst properties, operational parameters and light source
PublikacjaSelf-organized TiO2 nanotubes as immobilized photocatalysts were evaluated in detail for the photocatalytic degradation of parabens mixtures from ultrapure water. This kind of approach can be a very suitable option for emerging contaminants degradation considering the possibility of the catalyst reuse and recovery which will be simpler than when catalytic powders are used. The anodization method was applied for the TiO2 nanotubes...
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The influence of azide and imidazole on the properties of Mn- and Cd-based networks: conductivity and nonlinear phenomena
PublikacjaWe report a study on a family of four new Mn- and Cd-azide-imidazolate-based compounds with various crystal architectures. Notably, three of these compounds display noncentrosymmetric crystal arrangements at room temperature, a rare phenomenon in hybrid organic–inorganic materials. Both nonlinear optical (NLO) and electrical phenomena in these compounds are observed. The NLO processes include second and third harmonic generation,...
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A double-talk detector using audio watermarking
Publikacjaa novel approach to double-talk detection in the acoustic echo canceler is proposed. a hidden signature is embedded into the arriving signal, using the echo-hiding method. next detection of the presence of this signature in the microphone signal is performed. the results of the signature detection may be used by the acoustic echo canceler to stop or restart the adaptation process.
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Optical-Fiber Microsphere-Based Temperature Sensors with ZnO ALD Coating—Comparative Study
PublikacjaThis study presents the microsphere-based fiber-optic sensor with the ZnO Atomic Layer Deposition coating thickness of 100 nm and 200 nm for temperature measurements. Metrological properties of the sensor were investigated over the temperature range from 100 °C to 300 °C, with a 10 °C step. The interferometric signal was used to monitor the integrity of the microsphere and its attachment to the connecting fiber. For the sensor...
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Practical Trial for Low-Energy Effective Jamming on Private Networks With 5G-NR and NB-IoT Radio Interfaces
PublikacjaFourth-generation (4G) mobile networks are successively replaced by fifth-generation (5G) ones, based on the new releases of the 3rd Generation Partnership Project (3GPP) standard. 5G generation is dedicated to civilian users and the conducted analytical work shows that it has numerous technological gaps that prevent its direct implementation in military communications systems. However, the recent armed world conflicts showed that...
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Experimental Extraction of Secure Correlations from a Noisy Private State
PublikacjaWe report experimental generation of a noisy entangled four-photon state that exhibits a separation between the secure key contents and distillable entanglement, a hallmark feature of the recently established quantum theory of private states. The privacy analysis, based on the full tomographic reconstruction of the prepared state, is utilized in a proof-of-principle key generation. The inferiority of distillation-based strategies...
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A system for Direction-Of-Arrival estimation in ISM 2.4 GHz frequency band based on ESPAR antenna and SDR technology
PublikacjaDetermination of the direction of the signal arrival (DOA) finds many applications in various areas of science and industry. Knowledge of DOA is used, among others to determine the position of a satellite with a low Earth orbit (LEO), localization of people and things as well as in research of wireless communication systems, for instance the determination of the number of...
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The Methods for RTS Noise Identification
PublikacjaIn the paper authors present two methods, which allows to identify the RTS noise in noise signal of semiconductor devices. The first one was elaborated to identify the RTS noise and also to estimate the number of its levels. The second one can be used to estimate all of the parameters of Gaussian and non-Gaussian components in the noise signal in a frequency domain.
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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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HILS for the Design of Three-Wheeled Mobile Platform Motion Surveillance System with a Use of Energy Performance Index
PublikacjaCurrent tendency in mechatronic design requires the use of comprehensive development of an environment, which gives the possibility to prototype, design, simulate and integrate with dedicated hardware. The paper discusses the Hardware-In-the-Loop Simulations (HILS) mechatronic technique, used during the design of the surveillance system based on energy performance index. The presented test configuration (physical controller – emulated...
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Temperature Fiber-Optic Sensor with ZnO ALD Coating
PublikacjaThis study presents a microsphere-based fiber-optic sensor with a ZnO Atomic Layer Deposition (ALD) coating thickness of 100 nm for temperature measurements. Metrological properties of the sensor were investigated over the temperature range of 100 °C to 300 °C, with a 10 °C step. An interferometric signal is used to control whether the microstructure is whole. Spectrum shift of a reflected signal is used to ascertain changes in...
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New Design of Axial Piston Pump with Displaced Swash Plate Axis of Rotation for Hydro-Mechanical Transmissions
PublikacjaThis paper presents a prototype design of an axial piston pump with displaced swash plate axis of rotation in two directions of discharge with electronic control intended for installation on a hydraulic-mechanical gearbox dedicated to working machines. The effect of displacement of the swash plate rotation axis on dead space volume and volumetric efficiency is presented. The construction and principle of operation of the capacity...
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Measurements of the optical and thermal properties of the 2D black phosphorus coating
PublikacjaBlack phosphorus is a 2D material, which properties are still being discovered. In this paper, the sensitivity to the temperature of a few-layer black phosphorus coating deposited, on the surface of a microsphere-based fiber-optic sensor, by a dip-coating method is presented. The coating was investigated after 2, 3, and 5 deposition cycles and during temperature growth from 50 °C to 300 °C in an interferometric setup. The intensity...
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Reduction of the Multipath Propagation Effect in a Hydroacoustic Channel Using Filtration in Cepstrum
PublikacjaDuring data transmission in a hydroacoustic channel, one of the problems is the multipath propagation effect, which leads to a decrease in the transmission parameters and sometimes completely prevents it. Therefore, we have attempted to develop a method, which is based on a recorded hydroacoustic signal, that allows us to recreate the original (generated) signal by eliminating the multipath effect. In our method, we use cepstral...
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Investigation of the temperature modulation parameters on semiconductor gas sensor response
PublikacjaIn this work we present the results of the investigation of the sensing properties of semiconductor gas sensors with a sinusoidally modulated temperature in the presence of synthetic air (SA) and three volatile air pollutants, i.e. NH3, NO2 and SO2. The measurements were performed for different average sensor heater temperatures and the amplitude of the modulation signal. In addition, the extraction of features from the sensor...
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Design of OFDM-based radio communication systems for coast-to-sea and coast-to-air propagation environments
PublikacjaIn the paper the study of radio communication system design process for systems based on OFDM transmission is considered. The signal propagation model for 1.4 GHz frequency band is discussed, and the study of signal propagation characteristics, important from the point of view of OFDM system design, is presented. The methodology of OFDM interface design is proposed and some characteristics of the OFDM-based radio communication...
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Effect of synthesis method parameters on properties and photoelectrocatalytic activity under solar irradiation of TiO2 nanotubes decorated with CdS quantum dots
PublikacjaThe growing research interest on photoelectrocatalysis has encouraged the search for new materials with high activity and the development of methods for their synthesis. The successive ionic layer adsorption and reaction (SILAR) method is an effective way to synthesize materials with photoelectrocatalytic (PEC) properties that are active under visible radiation. Therefore, studies on the impact of the parameters of the SILAR method...
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Detection and Direction-of-Arrival Estimation of Weak Spread Spectrum Signals Received with Antenna Array
PublikacjaThis paper presents a method for the joint detection and direction of arrival (DOA) estimation of low probability of detection (LPD) signals. The proposed approach is based on using the antenna array to receive spread-spectrum signals hidden below the noise floor. Array processing exploits the spatial correlation between phase-delayed copies of the signal and allows us to evaluate the parameter used to make the decision about the...
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Running performance of an aerodynamic journal bearing with squeeze film effect
PublikacjaResults of theoretical and experimental studies concerning the performance of an aerodynamic journal bearing of which running is assisted by squeeze film ultrasonic levitation (SFUL) are presented in this paper. The SFUL mechanism not only can separate journal from the bearing at the start and stop phases of operation but also can significantly contribute to the dynamic stability of the bearing when it runs at speed. Computer calculations...
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Information transfer during the universal gravitational decoherence
PublikacjaRecently Pikovski et al. (Nat Phys 11:668, 2015) have proposed in an intriguing universal decoherence mechanism, suggesting that gravitation may play a conceptually important role in the quantum-to-classical transition, albeit vanishingly small in everyday situations. Here we analyze information transfer induced by this mechanism. We show that generically on short time-scales, gravitational decoherence leads to a redundant information...
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Instantaneous complex frequency for pipeline pitch estimation
PublikacjaIn the paper a pipeline algorithm for estimating the pitch of speech signal is proposed. The algorithm uses instantaneous complex frequencies estimated for four waveforms obtained by filtering the original speech signal through four bandpass complex Hilbert filters. The imaginary parts of ICFs from each channel give four candidates for pitch estimates. The decision regarding the final estimate is made based on the real parts of...
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Superresolution algorithm to video surveillance system
PublikacjaAn application of a multiframe SR (superresolution) algorithm applied to video monitoring is described. The video signal generated by various types of video cameras with different parameters and signal distortions which may be very problematic for superresolution algorithms. The paper focuses on disadvantages in video signal which occur in video surveillance systems. Especially motion estimation and its influence on superresolution...
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Application of thin diamond films in low-coherence fiber-optic Fabry Pérot displacement sensor
PublikacjaThe novel fiber-optic low coherence sensor with thin diamond films is demonstrated. The undoped and boron-doped diamond films were elaborated by the use of the microwave plasma enhanced chemical vapor deposition (μPE CVD) system. The optical signal from the Fabry–Pérot cavity made with the application of those thin films is sensitive to displacement. The sensor characterization was made in the range of 0–600 μm. The measurements...
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Comparison of Acoustic and Visual Voice Activity Detection for Noisy Speech Recognition
PublikacjaThe problem of accurate differentiating between the speaker utterance and the noise parts in a speech signal is considered. The influence of utilizing a voice activity detection in speech signals on the accuracy of the automatic speech recognition (ASR) system is presented. The examined methods of voice activity detection are based on acoustic and visual modalities. The problem of detecting the voice activity in clean and noisy...
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Rzadka reprezentacja sygnału niestacjonarnego w technice oszczędnego próbkowania
PublikacjaPrzedstawiono zastosowanie techniki oszczędnego próbkowania do rekonstrukcji sygnału niestacjonarnego na podstawie skompresowanych próbek w dziedzinie czas-częstotliwość. Zastosowano nadmiarowy algorytm z różnymi słownikami aby znaleźć rzadką reprezentację sygnału. Wyniki symulacji potwierdzają, że zastosowanie oszczędnego próbkowania pozwala na rekonstrukcję sygnału niestacjonarnego z małej liczby losowo pobranych próbek, z niewielką...
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Fully Adaptive Savitzky-Golay Type Smoothers
PublikacjaThe problem of adaptive signal smoothing is consid-ered and solved using the weighted basis function approach. Inthe special case of polynomial basis and uniform weighting theproposed method reduces down to the celebrated Savitzky-Golaysmoother. Data adaptiveness is achieved via parallel estimation.It is shown that for the polynomial and harmonic bases andcosinusoidal weighting sequences, the competing signal estimatescan be computed...
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From U2TP Models to Executable Tests with TTCN-3
PublikacjaThe approach towards system engineering according to Model-Driven Architectures (MDA) with code generation derived from model implies also an increased need for research on automation of the test generation process. This paper presents an approach to derive executable tests from UML 2.0 Testing Profile diagrams automatically. In particular, an approach to derive executable tests within the Testing and Test Control Notation (TTCN-3)...
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A vector-enzymatic DNA fragment amplification-expression technology for construction of artificial, concatemeric DNA, RNA and proteins for novel biomaterials, biomedical and industrial applications
PublikacjaA DNA fragment amplification/expression technology for the production of new generation biomaterials for scientific, industrial and biomedical applications is described. The technology enables the formation of artificial Open Reading Frames (ORFs) encoding concatemeric RNAs and proteins. It recruits the Type IIS SapI restriction endonuclease (REase) for an assembling of DNA fragments in an ordered head-to-tail-orientation. The...
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Audio codec employing frequency-derived tonality measure
PublikacjaA transform codec employing efficient algorithm for detection of spectral tonal components is presented. The tonality measure used in MPEG psychoacoustic model is replaced with the method providing adequate tonality estimates even if the tonal components are deeply frequency modulated. The reliability of hearing threshold estimated using psychoacoustic model with standardized tonality measure and the proposed one is investigated...
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Position Estimation in Corridors Along the Coupled Mode of Radiating Cables
PublikacjaRadiating cables are mostly used to provide radio communication in tunnels or corridors, but they can also be used to estimate the position of a mobile terminal along the cable. In this paper, a measuring receiver’s position was estimated by measuring the difference in the direct signal’s reception time, which was generated by a transmitter connected to one end of the radiating cable, and the delayed signal retransmitted from another...
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Quality Evaluation of Novel DTD Algorithm Based on Audio Watermarking
PublikacjaEcho cancellers typically employ a doubletalk detection (DTD) algorithm in order to keep the adaptive filter from diverging in the presence of near-end speech signal or other disruptive sounds in the microphone signal. A novel doubletalk detection algorithm based on techniques similar to those used for audio signal watermarking was introduced by the authors. The application of the described DTD algorithm within acoustic echo cancellation...
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Atomic Force Microscope data post-processing algorithm for higher harmonics imaging
PublikacjaPrevious works have proved that higher harmonics topography imaging using atomic force microscope (AFM) can significantly enhanced its measurement capabilities. Integrated tools dedicated to most of microscopes allow to visualize the investigated surface only by one selected harmonic. Because of the different characteristics of a sample, scanning tip and the environment, appropriate harmonic selection is time consuming and requires...
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Ultrasonic spectroscopy of silicon single crystal
PublikacjaSpecimens of Si single crystals with different crystal orientation [100] and [110] were studied by the electro-ultrasonic spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: electric AC signal and ultrasonic signal,...
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Implementation of DIFAR Processing in ASW Dipping Sonar
PublikacjaThis paper presents the implementation of the signal processing algorithm used by buoy DIFAR (Directional Frequency Analysis and Recording), that is fully operational on Polish Navy anti-submarine warfare (ASW) helicopters and ships, applied to dipping sonars for detection and tracking of submarines. The development of the DSP algorithms was a part of the modernization of sonars conducted at the Gdansk University of Technology....
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A New Coupler Concept for Contactless High-Speed Data Transmission Monitoring
PublikacjaThis paper presents a new concept of a couplerthat can be applied to high-speed data transmission contactlessmeasurements. The proposed approach is dedicated for differentialsignal transmission monitoring in microstrip coupled lineson printed circuit boards (PCBs). The coupler, produced on aseparate PCB, is overlayed on the transmission line with thedifferential signal and delivers decoupled differential signal tothe main measurement...