Wyszukiwarka
Wyniki wyszukiwania dla: noise modeling
-
Applicability of null-steering for spoofing mitigation in civilian GPS
PublikacjaCivilian GPS signals are currently used in many critical applications, such as precise timing for power grids and telecommunication networks. Spoofing may cause their improper functioning. It is a threat which emerges with the growing availability of GPS constellation simulators and other devices which may be used to perform such attack. Development of the effective countermeasures, covering detection and mitigation, is necessary...
-
The Innovative Faculty for Innovative Technologies
PublikacjaA leaflet describing Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology. Multimedia Systems Department described laboratories and prototypes of: Auditory-visual attention stimulator, Automatic video event detection, Object re-identification application for multi-camera surveillance systems, Object Tracking and Automatic Master-Slave PTZ Camera Positioning System, Passive Acoustic Radar,...
-
Testing Watermark Robustness against Application of Audio Restoration Algorithms
PublikacjaThe purpose of this study was to test to what extent watermarks embedded in distorted audio signals are immune to audio restoration algorithm performing. Several restoration routines such as noise reduction, spectrum expansion, clipping or clicks reduction were applied in the online website system. The online service was extended with some copyright protection mechanisms proposed by the authors. They contain low-level music features...
-
Analysis of Denoising Autoencoder Properties Through Misspelling Correction Task
PublikacjaThe paper analyzes some properties of denoising autoencoders using the problem of misspellings correction as an exemplary task. We evaluate the capacity of the network in its classical feed-forward form. We also propose a modification to the output layer of the net, which we called multi-softmax. Experiments show that the model trained with this output layer outperforms traditional network both in learning time and accuracy. We...
-
Research on causes of corrosion in the municipal water supply system
PublikacjaThis paper presents results of failure analysis study to characterize the corrosion damage that occurred in the water supply system in Krakow. This analysis includes: electrochemical noise, linear polarization and resistometric measurements. Water aggressiveness of four water intakes was defined using Langelier and Ryznar indices. Results from this indices did not reveal the causes of considerable corrosion losses in water systems....
-
Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublikacjaNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...
-
MEMS Gyro in the Context of Inertial Positionning
PublikacjaThe article undertake some vital aspect in geodesy, namely an inertial positioning problem using MEMS. Although MEMS inertial sensors offer affordable, appropriately scaled units, and though their inherent measurement noise can be relatively easily mitigated, there are still parameters due to they are not currently capable of meeting all requirements for the accurate and precise inertial positioning. The article presents crucial...
-
Fixed Pattern Noise Reduction and Linearity Improvement in Time-Mode CMOS Image Sensors
PublikacjaIn the paper, a digital clock stopping technique for gain and offset correction in time-mode analog-to-digital converters (ADCs) has been proposed. The technique is dedicated to imagers with massively parallel image acquisition working in the time mode where compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. Fixed pattern noise (FPN) reduction has been experimentally validated...
-
SAMPLE-AND-HOLDING METHOD FOR GAS SENSING APPLIED FOR RESISTANCE GAS SENSORS
PublikacjaThe DC resistance of a Taguchi gas sensor is influenced by the ambient gas. To improve the selectivity and sensitivity of a sensor the fluctuation enhanced sensing (FES) was used. The paper proposes a novel methodology of utilizing FES technique that sample composition of an ambient atmosphere and hold it for further processing (sample-and-holding technique). The method uses the heated gas sensor to sample an ambient atmosphere...
-
New satellite pumps
PublikacjaStosowanie Maszyn company from Katowice was initiator and originator of newest original high pressure satellite pumps series of types PSM. Construction solution, research and development of these pumps have been conducted by Team of Hydraulics and Pneumatics of Gdansk University of Technology in cooperation with this company within the confines of research project nr R0300103 (source of funds: Ministry of Science and Higher Education)....
-
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...
-
A Measurement-Based Approach for Speed Control of Induction Machines
PublikacjaThis paper presents an approach to design a measurement-based controller for induction machines. The proposed control approach is motivated by the fact that developing an appropriate mechanical model of such induction machines is a challenging task. Since our proposed control methodology is only on the basis of measured data, the controller design does not require any information about the model of the mechanical part. The control...
-
Performance analysis of data transmission in MC-CDMA radio interface with turbo codes
PublikacjaMulti-carrier code division multiple access (MC-CDMA) technique is a combination of two radio access techniques: CDMA and orthogonal frequency division multiplexing and has the advantages of both techniques. The paper presents the design of transmitter and receiver for MC-CDMA radio interface. It also presents encoders and decoders of turbo codes which were used in simulation of the MC-CDMA technique. Two turbo codes with 8-state...
-
Arm EMG Wavelet-Based Denoising System
PublikacjaThese paper presents research results of muscle EMG signal denoising. In the same time two muscles were examined - an adductor muscle (biceps brachii) and an abductor muscle (tricpeps brachii). The EMG signal was filtered using the wavelet transform technique, having selected the crucial parameters as: wavelet basis function (Daubechies 4), 10 th decomposition level, threshold selection algorithm (Heurestic) and a sln rescaling...
-
Objectivity in a Noisy Photonic Environment through Quantum State Information Broadcasting
PublikacjaRecently, the emergence of classical objectivity as a property of a quantum state has been explicitly derived for a small object embedded in a photonic environment in terms of a spectrum broadcast form—a specific classically correlated state, redundantly encoding information about the preferred states of the object in the environment. However, the environment was in a pure state and the fundamental problem was how generic and robust...
-
Dynamical objectivity in quantum Brownian motion
PublikacjaClassical objectivity as a property of quantum states —a view proposed to explain the observer-independent character of our world from quantum theory, is an important step in bridging the quantum-classical gap. It was recently derived in terms of spectrum broadcast structures for small objects embedded in noisy photon-like environments. However, two fundamental problems have arisen: a description of objective motion and applicability...
-
The environmental dimension of city dwellers’ quality of life and the city’s social and spatial variability
PublikacjaThe purpose of this paper is to attempt an analysis of the environmental dimension of the quality of life using quantitative surveys conducted among residents of Gdańsk. In the paper, we make reference to the theoretical assumptions ensuing from the concept of a comprehensive and integrated approach to the development of the urban environment, whilst noting the profound impact humans bring to their evaluation of the environmental...
-
A simplified channel estimation procedure for NB-IoT downlink
PublikacjaThis paper presents a low-complexity channel estimation procedure which is suitable for use in energy-efficient NB-IoT user equipment devices. The procedure is based on the well-established least squares scheme, followed by linear interpolation in the time domain and averaging in the frequency domain. The quality of channel estimation vs. signal-to-noise ratio is evaluated for two channel models and compared with the performance...
-
EMI attenuation in a DC-DC buck converter using GaN HEMT
PublikacjaA dc-dc buck converter using gallium nitride (GaN) high electron mobility transistors (HEMT) is experimentally investigated at the discontinuous current mode (DCM) and at the triangular current mode (TCM) operation. The paper objective is to specify the power conversion efficiency and attenuation of common mode (CM) and differential mode (DM) noise voltage, measured at the line impedance stabilization network (LISN) for compared...
-
Adaptive Wavelet-Based Correction of Non-Anechoic Antenna Measurements
PublikacjaNon-anechoic measurements represent an affordable alternative to evaluation of antenna performance in expensive, dedicated facilities. Due to interferences and noise from external sources of EM radiation, far-field results obtained in non-ideal conditions require additional post-processing. Conventional correction algorithms rely on manual tuning of parameters, which make them unsuitable for reliable testing of prototypes. In this...
-
Modelowanie hałasu samochodu osobowego w ruchu drogowym.
PublikacjaPrzedmiotem niniejszej pracy doktorskiej było opracowanie empirycznego modelu hałasu emitowanego przez samochody, pozwalającego na określenie hałasu w dowolnych warunkach ruchu pojazdu oraz nadającego się do analizy parametrycznej wpływu podstawowych parametrów ruchu na emitowany hałas. W ramach pracy opracowano metodykę a następnie przeprowadzono badania drogowe hałasu ośmiu pojazdów. Na podstawie uzyskanych charakterystyk emisji...
-
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...
-
Analogue GPS repeater
PublikacjaThis article concerns the problem of difficulty in correct indoor Global Positioning System (GPS) signals reception due to attenuation. Radio signal repeaters are proposed as means to solve this problem. Firstly, the GPS signal characteristics are described, emphasizing their low power in the point of reception. In the second part, various applications of GPS signal repeater, where indoor GPS signals reception is required, are...
-
SONIC - Self-optimizing narrowband interference canceler: comparison of two frequency tracking strategies
PublikacjaThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time linear stable plant with unknown and possibly time-varying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measurement noise. The proposed disturbance...
-
Fluctuation-Enhanced Sensing for Biological Agent Detection and Identification
PublikacjaPrzedstawiono wcześniejsze wyniki badań dotyczące trzech różnych sposobów wykrywania obecności substancji biologicznych za pomocą zjawisk fluktuacyjnych: 1) wirusów wnikających do komórek, 2) zapachów emitowanych przez mikroby, 3) rozkładu widma i wartości chwilowych szumów podczas rozpraszania światła używanego do wykrywania zarodników na podstawie wyznaczenia współczynnika dyfuzji opisująceo ich ruch.We survey and show our earlier...
-
Analytical Expression for the Time-Domain Discrete Green's Function of a Plane Wave Propagating in the 2-D FDTD Grid
PublikacjaIn this letter, a new closed-form expression for the time-domain discrete Green's function (DGF) of a plane wave propagating in the 2-D finite-difference time-domain (FDTD) grid is derived. For the sake of its verification, the time-domain implementation of the analytic field propagator (AFP) technique was developed for the plane wave injection in 2-D total-field/scattered-field (TFSF) FDTD simulations. Such an implementation of...
-
SYSTEM IDENTYFIKACJI SZUMÓW RTS TRANSOPTORÓW CNY17
PublikacjaW artykule opisano zaprojektowany i wykonany system do identyfikacji szumów wybuchowych (RTS – Random Telegraph Signal) występujących w transoptorach typu CNY17. Z metod umożliwiających ocenę parametrów szumów wybuchowych wybrano do realizacji metodę Wzorów Obrazów Szumów – WOS (ang. Noise Scattering Patterns – NSP), która w sposób bardzo prosty pozwala na rozpoznawanie szumów o rozkładach wartości chwilowych gaussowskich i niegaussowskich....
-
The instantaneous frequency rate spectogram
PublikacjaAn accelerogram of the instantaneous phase of signal components referred to as an instantaneous frequency rate spectrogram (IFRS) is presented as a joint time-frequency distribution. The distribution is directly obtained by processing the short-time Fourier transform (STFT) locally. A novel approach to amplitude demodulation based upon the reassignment method is introduced as a useful by-product. Additionally, an estimator of energy...
-
Analytical Expression for the Time-Domain Green's Function of a Discrete Plane Wave Propagating in the 3-D FDTD Grid
PublikacjaIn this paper, a closed-form expression for the time-domain dyadic Green’s function of a discrete plane wave (DPW) propagating in a 3-D finite-difference time-domain (FDTD) grid is derived. In order to verify our findings, the time-domain implementation of the DPW-injection technique is developed with the use of the derived expression for 3-D total-field/scattered-field (TFSF) FDTD simulations. This implementation requires computations...
-
Recurrence scheme for FDTD-compatible discrete Green's function derived based on properties of Gauss hypergeometric function
PublikacjaIn this paper, the formulation of one-dimensional FDTD (Finite-difference time-domain)-compatible discrete Green's function (DGF) is derived based on the Gauss hypergeometric function (GHF). The properties of GHF make it possible to derive the recurrence scheme only in the time domain for the DGF generation. Furthermore, this recurrence scheme is valid for any stable time-step size and can be implemented using standard numerical...
-
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...
-
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...
-
Auto-Correction of Non-Anechoic Antenna Measurements Based on Multi-Taper Approach
PublikacjaMeasurements of antenna prototypes are normally performed in dedicated, yet costly environments such as anechoic chambers (ACs). However, the AC construction cost might be unjustified when the measurements aim to support education, or budget-tight research. Alternatively, experiments can be realized in non-anechoic regime and refined using appropriate methods. In this letter, a framework for correction of antenna far-field measurements...
-
Investigations of the Methods of Time Delay Measurement of Stochastic Signals Using Cross-correlation with the Hilbert Transform
PublikacjaThe article presents the results of simulation studies of four methods of estimating time delay for random signals using cross-correlation with the Hilbert Transform. Selected models of mutually delayed stochastic signals were used in the simulations, corresponding to the signals obtained from scintillation detectors in radioisotope measurements of liquid-gas two-phase flow. Standard deviations of the values of the individual functions...
-
Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublikacjaIn this article, specific methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...
-
Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublikacjaIn this study, dedicated methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...
-
Performance of acicular grindable thermocouples for temperature measurements at sliding contacts
PublikacjaThe present study investigates the performance of acicular grindable thermocouples based on a constantan wire / steel hollow cylinder construction. The experiments showed that the measuring junction electrical resistance, temperature–voltage characteristic, measuring junction rise time and signal noise standard deviation of the acicular thermocouples are comparable to those of conventional J-type thermocouples with bare wire diameter...
-
New approaches for improving selectivity and sensitivity of resistive gas sensors: A review
PublikacjaResistive gas sensors are very popular and reliable but suffer from low selectivity and sensitivity. Various methods have been suggested to improve both features without increasing the number of sensors in gas detection systems. Fluctuation enhanced gas sensing was proposed to improve gas detection efficiency by analyzing low-frequency resistance fluctuations, and noise parameters can be more informative than the single DC resistance...
-
Visual Traffic Noise Monitoring in Urban Areas
PublikacjaThe paper presents an advanced system for railway and road traffic noise monitoring in metropolitan areas. This system is a functional part of a more complex solution designed for environmental monitoring in cities utilizing analyses of sound, vision and air pollution, based on a ubiquitous computing approach. The system consists of many autonomous, universal measuring units and a multimedia server, which gathers, processes and...
-
Reduction of Tire Rolling Resistance by Optimization of Road Surfaces and Tires
PublikacjaDuring interaction between tire and road surface three very important phenomena are always in effect. One of them (very desirable) is friction that is important for traction, braking and cornering. Two other phenomena are not desirable at all, that is rolling resistance and noise. This paper discusses relations between road surface and tire parameters versus tire rolling resistance. Road surface texture, porosity, impedance, strength...
-
Gdansk Bay sea bed sounding and classification of its results
PublikacjaThe main goal of this paper is to describe the results of sounding the Gdansk Bay sea bed by using a SES-2000 Standard parametric sub-bottom profiler. Quality of data obtained during trials depends inter alia on a proper location of transducer array to reduce influence of pitch, roll and heave motions as well as ship self noise (resulting from bubbles due to propeller and flow around hull, vibration generated by main engine and...
-
Stress anisotropy characterisation with the help of Barkhausen effect detector with adjustable magnetic field direction
PublikacjaIn the paper we describe a novel apparatus for the measurement of the Barkhausen noise (BN) angular dependence, which in turn may be indicative of the stress induced anisotropy of magnetic properties. Such dependence can be further used for the stress distribution evaluation. The change of magnetization direction in the material is obtained by varying the magnetic flux density in two perpendicular yokes of the apparatus. We present...
-
Improving listeners' experience for movie playback through enhancing dialogue clarity in soundtracks
PublikacjaThis paper presents a method for improving users' quality of experience through processing of movie soundtracks. The dialogue clarity enhancement algorithms were introduced for detecting dialogue in movie soundtrack mixes and then for amplifying the dialogue components. The front channel signals (left, right, center) are analyzed in the frequency domain. The selected partials in the center channel signal, which yield high disparity...
-
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,...
-
Application of the Mathar method to identify internal stress variation in steel as a welding process result
PublikacjaThe paper deals with the method to identify internal stresses in two-dimensional steel members. Steel members were investigated in the delivery stage and after assembly, by means of electric-arc welding. In order to perform the member assessment two methods to identify the stress variation were applied. The first is a non-destructive measurement method employing local external magnetic field and to detecting the induced voltage,...
-
Counting and tracking vehicles using acoustic vector sensors
PublikacjaA method is presented for counting vehicles and for determining their movement direction by means of acoustic vector sensor application. The assumptions of the method employing spatial distribution of sound intensity determined with the help of an integrated 3D intensity probe are discussed. The intensity probe developed by the authors was used for the experiments. The mode of operation of the algorithm is presented in conjunction...
-
Tinnitus Therapy Based on High-Frequency Linearization Principles - Preliminary Results
PublikacjaThe aim of this work is to present problems related to tinnitus symptoms, its pathogenesis, hypotheses on tinnitus causes, and therapy treatment to reduce or mask the phantom noise. In addition, the hypothesis on the existence of parasitic quantization that accompanies hearing loss has been recalled. Moreover, the paper describes a study carried out by the Authors with the application of high-frequency dither having specially formed...
-
Planning, Configuration and Usefulness of Microseismic Monitoring on Eastern-Europe Platform – Example from East Pomerania
PublikacjaThe microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing process. The method uses array of geophones to localize micro tremors induced by liquid pumped underground at high rate and pressure. The acquired information helps to optimize fracturing process and prevents fracture growth to aquifer levels. It proved to be useful on several unconventional hydrocarbon reservoirs in the USA....
-
Redundant information encoding in QED during decoherence
PublikacjaBroadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927)] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many real-life situations, has...
-
Multibeam data processing for 3D object shape reconstruction
PublikacjaThe technology of hydroacoustic scanning offers an efficient and widely-used source of geospatial information regarding underwater environments, providing measurement data which usually have the structure of irregular groups of points known as point clouds. Since this data model has known disadvantages, a different form of representation based on representing surfaces with simple geometric structures, such as edges and facets,...