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wszystkich: 188
Wyniki wyszukiwania dla: SURFACE DISTURBANCES
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Propagation of Acoustic Disturbances in Shallow Sea
PublikacjaPropagation of acoustic waves in shallow sea differs fundamentally from the same phenomenon occurring in deep sea in view of non-negligible distance from the sea bottom in the first case, where presence of two regions limiting the water layer results in the acoustic pressure distribution induced by a harmonic source has an interferential nature as a result of multi-path propagation of the acoustic signal. These interferential properties...
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EMC disturbances in connection of driving system
PublikacjaIt is known the steep voltage changes caused by IGBT frequency inverters may cause some electromagnetic problems in driving system. Special dU/dt type as well as sinusoidal filters are used in order to limit the level of the disturbances. The paper presents investigation results of EMC disturbances in inverter supplied induction motor. Experiments have proved that disturbances in current connection differ essentially. Important...
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Magnetic disturbances caused by magnetic contamination of plastics
PublikacjaIn the study of low magnetic fields precision magnetometers working in a differential system are used. Two optically pumped magnetometers working in a differential system allow for precise measuring of disturbances in the magnetic field. In order to attain high accuracy of magnetic field measurement, it is necessary to use appropriate materials for the construction of a magnetometric system, particularly of those located closely...
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Detection of impulsive disturbances in archive audio signals
PublikacjaIn this paper the problem of detection of impulsive disturbances in archive audio signals is considered. It is shown that semi-causal/noncausal solutions based on joint evaluation of signal prediction errors and leave-one-out signal interpolation errors, allow one to noticeably improve detection results compared to the prediction-only based solutions. The proposed approaches are evaluated on a set of clean audio signals contaminated...
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The laboratory kit of EMC disturbances sources
PublikacjaPrzedstawiono podstawowe przyczyny powstawania zakłóceń w urządzeniach elektrycznych i elektronicznych oraz metody i sposoby ich analizy. Przedstawiono również koncepcje układów elektronicznych mających być wzorcowymi źródłami zaburzeń stosowanymi podczas ćwiczeń laboratoryjnych. Jako źródła zaburzeń małych i wysokich częstotliwości wybrano układy mogące być łatwo sterowane i zmieniane w celu wskazania konieczności stosowania rozwiązań...
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Disturbances of magnetic field of plane caused by eddy currents
PublikacjaResults of the numerical analysis of the magnetic disturbances of a plane caused by eddy currents induced in conducting elements of the plane were presented in this paper. Magnetic disturbances of the object's model were carried out in Opera 3D.
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Blackout initial disturbances in electric Power System searching
PublikacjaThe paper contains short survey of the blackouts that took place in the last few years. The sources and initial disturbances are discussed. The typical scenario of the disturbance, leading to blackout in the electrical power system are presented.Next, models of a power system eligible to considered topic are discussed. Finally the algorithm of the blackout initial disturbances in power system searching is presented.The consideration...
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Active feedback noise control in the presence of impulsive disturbances
PublikacjaThe problem of active feedback control of a narrowband acoustic noise in the presence of impulsive disturbances is considered. It is shown that, when integrated with appropriately designed outlier detector, the proposed earlier feedback control algorithm called SONIC is capable of isolating and rejecting noise pulses. According to our tests this guarantees stable and reliable operation of the closed-loop noise cancelling...
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Surface irregularities as a complex signal of tool representation together with uneven displacement in respect to the workpiece
PublikacjaIn a dynamic machining process, distortion in surface irregularity is a very complex phenomenon. Surface irregularities form a periodic representation of the tool profile with various kinds of disturbance in a broad range of changes in the height and length of the profile. To discern these irregularity disturbances, interactions of the tool in the form of changes perpendicular and parallel relative to the workpiece were analyzed...
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Disturbances of magnetic field in surrounding of mobile, metalic plate
PublikacjaThe uniform magnetic field of the Earth in the surrounding of a mobile, metalic object undergoes deformation by eddy currents. The influence of the moving conducting object on total magnetic field of the Earth depends on the object's shape, position and speed of the changes relative to the magnetic field's vector of the Earth as well as the electric conductivity and the relative magnetic permeability of the material. The disturbances...
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Elimination of impulsive disturbances from stereo audio recordings
PublikacjaThis paper presents a new approach to elimination of impulsive disturbances from stereo audio recordings. The proposed solution is based on vector autoregressive modeling of audio signals. On-line tracking of signal model parameters is performed using the stability-preserving Whittle-Wiggins-Robinson algorithm with exponential data weighting. Detection of noise pulses and model-based interpolation of the irrevocably distorted samples...
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Active Suppression of Nonstationary Narrowband Acoustic Disturbances
PublikacjaIn this chapter, a new approach to active narrowband noise control is presented. Narrowband acoustic noise may be generated, among others, by rotating parts of electro-mechanical devices, such as motors, turbines, compressors, or fans. Active noise control involves the generation of “antinoise”, i.e., the generation of a sound that has the same amplitude, but the opposite phase, as the unwanted noise, which causes them to interfere...
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The Disturbances of the Zinc Concentration in the Blood in Selected Neoplasms
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Reproductive Consequences of Electrolyte Disturbances in Domestic Animals
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Analysis of magnetic disturbances of air platform caused by induced magnetisation
PublikacjaMagnetometric systems installed on air platforms like airplanes or helicopters are equipped in compensators of magnetic disturbances. Time changes of the platform's position caused generation of magnetic disturbances. The permanent and induced magnetization of ferromagnetic elements and eddy currents induced in conducting parts of the platform are sources of these disturbances. The linear model of magnetic disturbances of platforms...
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Localization of impulsive disturbances in audio signals using template matching
PublikacjaIn this paper, a new solution to the problem of elimination of impulsive disturbances from audio signals, based on the matched filtering technique, is proposed. The new approach stems from the observation that a large proportion of noise pulses corrupting audio recordings have highly repetitive shapes that match several typical “patterns”. In many cases a representative set of exemplary pulse waveforms can be extracted from the...
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Disturbances of Earth magnetic field caused by eddy currents of airplane
PublikacjaThe uniform magnetic field of the Earth in the surrounding of a mobile, metallic object undergoes deformation by eddy currents. The influence of the moving, conducting object on the Earth's total magnetic field depends on the object's shape, position and speed of the changes relative to the magnetic field vector of the Earth, as well as the electric conductivity and the relative magnetic permeability of the material. Disturbances...
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The Influence of Fluorine on the Disturbances of Homeostasis in the Central Nervous System
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The Disturbances of Magnesium in Patients With Thromboembolic Complications After a Cholecystectomy
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Disturbances of biological N-removal processes in the presence of sulphonamides
PublikacjaBadano podatność na biodegradację oraz wpływ na efektywność nitryfikacji wybranych sulfonamidów (sulfanilamidu SA, sulfacetamidu SCM oraz p-toluenosulfonamidu p-TSA). Podatnośc na biodegradację badano przy użyciu testu OECD 301D (test zamkniętej butelki). Efektywność nitryfikacji miarzono zgodnie z ISO 9509:1989. Stwierdzono, że wszystkie badane związki wykazują bardzo słabą podatność na biodegradację oraz mają wyraźny wpływ na...
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Automated Diagnostics of Current Pick-Up Disturbances in Electric Traction Networks
PublikacjaThe present work defines the basic causes of bow disturbances of current pick-up, sets a task of establishing a system of automated control of bow disturbances at feeder zones of electric traction networks, proposes structural variants of the technical system implementation, describes the algorithm of detection of bow disturbances of current pick-up.
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A new index for statistical analyses and prediction of travelling ionospheric disturbances
PublikacjaTravelling Ionospheric Disturbances (TIDs) are signatures of atmospheric gravity waves (AGWs) observed in changes in the electron density. The analysis of TIDs is relevant for studying coupling processes in the thermosphere–ionosphere system. A new TID index is introduced, which is based on an easy extension of the commonly used approach for TID detection. This TID activity index, which can be applied for individual Global Navigation...
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An Impact of Environmental Disturbances on Combined Cycle Power Plant Control
PublikacjaCombined cycle power plants operate at thermal efficiency approaching 60 percent. In the same time their performance presents several problems that have to be addressed. E.g. gas turbines are very sensitive to backpressure exerted on them by the heat recovery steam generators as well as to ambient pressure and temperature.
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Compensation of magnetic disturbances caused by sensors in a differential magnetometric system
PublikacjaStudy of low magnetic fields necessitates the use of precision magnetometers working in a differential system. Minimization of this error is a substantial issue in the case of magnetometers working in a differential system on a mobile platform. The compensation method of heading error consists in taking measurements of changes in magnetic induction with the use of the tested magnetometer for various locations of the sensor in relation...
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On the power systems performance control starting from disturbances measurements
PublikacjaReferat przedstawia badanie działania układu sterowania w systemie elektroenergetycznym oparte na oszacowanie parametrów. Na podstawie pomiarów wykonanych w stanie zakłóconiowym, parametry te są oszacowane minimizując uchyb pomiędzy wartościami wielkości uzyskanych z pomiarów i wartościami wielkości wyjściowych modelu systemu elektroenergetycznego. W celu zmniejszenia tego uchybu, proponowano dwie metody: klasyczna oparta na czułości...
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Analysis of the influence of ferromagnetic contaminations in plastics on the measurements of disturbances of magnetic field of the Earth
PublikacjaPlastics can be contaminated with small particles or filings with ferromagnetic properties. These contaminations cause significant disturbances in the magnetic field in the case of taking measurements of very low magnetic fields. The analysis of the influence of contaminated plastics on magnetic measurements is presented in this paper.
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Elimination of Impulsive Disturbances From Archive Audio Signals Using Bidirectional Processing
PublikacjaIn this application-oriented paper we consider the problem of elimination of impulsive disturbances, such as clicks, pops and record scratches, from archive audio recordings. The proposed approach is based on bidirectional processing—noise pulses are localized by combining the results of forward-time and backward-time signal analysis. Based on the results of specially designed empirical tests (rather than on the results of theoretical analysis),...
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Localization of impulsive disturbances in archive audio signals using predictive matched filtering
PublikacjaThe problem of elimination of impulsive disturbances from archive audio signals is considered and its new solution, called predictive matched filtering, is proposed. The new approach is based on the observation that a large percentage of noise pulses corrupting archive audio recordings have highly repetitive shapes that match several typical “patterns”, called click templates. To localize noise pulses, click templates can be correlated...
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Characteristics of sleep disturbances in Poland – results of the National Health Interview Survey
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Sparse vector autoregressive modeling of audio signals and its application to the elimination of impulsive disturbances
PublikacjaArchive audio files are often corrupted by impulsive disturbances, such as clicks, pops and record scratches. This paper presents a new method for elimination of impulsive disturbances from stereo audio signals. The proposed approach is based on a sparse vector autoregressive signal model, made up of two components: one taking care of short-term signal correlations, and the other one taking care of long-term correlations. The method...
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Analysis of electromagnetic disturbances in DC network of grid connected building-integrated photovoltaic system
PublikacjaThis paper focuses on conducted electromagnetic interference (EMI) emissions and propagation in the DC network of grid connected building integrated photovoltaic (PV) system. The investigated PV system, consists of ten solar panels, cabling and the grid-connected one phase inverter. The EMI simulation model of the real PV system has been developed with the aid of impedance analyzer measurements of solar panels and the DC network...
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New semi-causal and noncausal techniques for detection of impulsive disturbances in multivariate signals with audio applications
PublikacjaThis paper deals with the problem of localization of impulsive disturbances in nonstationary multivariate signals. Both unidirectional and bidirectional (noncausal) detection schemes are proposed. It is shown that the strengthened pulse detection rule, which combines analysis of one-step-ahead signal prediction errors with critical evaluation of leave-one-out signal interpolation errors, allows one to noticeably improve detection results...
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Effects of geomagnetic disturbances in daytime variations of the atmospheric electric field in polar regions
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Galvanic isolation circuit for measuring systems operating in environments with strong electromagnetic disturbances
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Piecewise continuous distribution function method in the theory of wave disturbances of inhomogeneous gas
PublikacjaUkład równań typu hydrodynamicznego dla warstwowych gazów w polu grawitacyjnym pochodzi od równania BGK metodą częściowej ciągłej funkcji dystrybucji. Otrzymany system równań uogólnia układ Naviera-Stokesa w dowolnych liczbach Knudsena.
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Expert systems in assessing the construction process safety taking account of the risk of disturbances
PublikacjaThe objective of the paper is to present the issue of safety manage-ment during the construction process. Threats in the form of disturb-ances may occur in the preparatory phase, during the execution of the construction project and also during its operational use. The arti-cle presents the concept of applying the methodology based, among others, on Learning Bayesian Networks, Artificial Neural Networks and Support Vector Machine,...
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Control System Design for Dynamic Positioning using Vectorial Backstepping
PublikacjaThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. The computer simulation results were given to...
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Piecewise continuous distribution function method: Fluid equations and wave disturbances at stratified gas
PublikacjaUkład równań typu hydrodynamicznego dla warstwowych gazów w polu grawitacyjnym pochodzi od równania BGK metodą częściowej ciągłej funkcji dystrybucji. Otrzymany system równań uogólnia układ Naviera-Stokesa w dowolnych liczbach Knudsena. Rozwiązania WBK dla ultradźwięku wprowadza się w przypadku stratyfikacji exponecjalnej.
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Blood pressure disturbances and endothelial dysfunction markers in children and adolescents with type 1 diabetes
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Random components influence on the values characterising periodic disturbances in low voltage supply lines.
PublikacjaAnalizowano wpływ składowych losowych na wielkości charakteryzujących zaburzenia okresowe w napięciu zasilania na przykładzie współczynnika zawartości harmonicznych (THD). Zaprezentowano sposób wyznaczania niepewności pomiaru współczynnika THD, uwzględniający występowanie korelacji pomiędzy składową podstawową i kolejnymi harmonicznymi napięcia sieci a także między poszczególnymi harmonicznymi. Przedstawiono analizę wyników z pomiarów...
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Reliability model of the crankshaft-piston assembly
PublikacjaThe laws that govern the durability of crankshaft-piston assembly friction nodes can be proved or at least derived or justified in an intuitive way. Operation of all the friction nodes is disturbed by external factors occurring with randomly changing intensity and also appearing at random. As the crankshaft-piston assembly friction nodes have a series structure and effects of those disturbances accumulate, their fitness for use...
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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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Model Predictive Super-Twisting Sliding Mode Control for An Autonomous Surface Vehicle
PublikacjaThis paper presents a new robust Model Predictive Control (MPC) algorithm for trajectory tracking of an Autonomous Surface Vehicle (ASV) in presence of the time-varying external disturbances including winds, waves and ocean currents as well as dynamical uncertainties. For fulfilling the robustness property, a sliding mode control-based procedure for designing of MPC and a super-twisting term are adopted. The MPC algorithm has been...
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A New Fuzzy Sliding Mode Controller with PID Sliding Surface for Underwater Manipulators
PublikacjaDesign of an accurate and robust controller is challenging topic in underwater manipulator control. This is due to hydrodynamic disturbances in underwater environment. In this paper a sliding mode control (SMC) included a PID sliding surface and fuzzy tunable gain is designed. In this proposed controller robustness property of SMC and fast response of PID are incorporated with fuzzy rules to reduce error tracking. In the control...
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Pathogenesis of psoriasis in the “omic” era. Part I. Epidemiology, clinical manifestation, immunological and neuroendocrine disturbances
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Homeopathic remedies as placebo alternatives — verification on the example of treatment of menopause-related vegetative and emotional disturbances
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Dynamic Positioning System with Vectorial Backstepping Controller
PublikacjaThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. Some parameters of observer were optimized off-line...
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Elimination of Impulsive Disturbances From Stereo Audio Recordings Using Vector Autoregressive Modeling and Variable-order Kalman Filtering
PublikacjaThis paper presents a new approach to elimination of impulsive disturbances from stereo audio recordings. The proposed solution is based on vector autoregressive modeling of audio signals. Online tracking of signal model parameters is performed using the exponential ly weighted least squares algo- rithm. Detection of noise pulses an d model-based interpolation of the irrevocably distorted sampl es is realized using an adaptive, variable-order...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublikacjaThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublikacjaThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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Disturbances of magnetic field in surrounding of mobile, metallic plate. Detection of ferromagnetic objects in strong local magnetic anomaly
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Profile irregularities of turned surfaces as a result of machine tool interactions
PublikacjaThe paper describes the influence of the machining operation on a surface, which disturbs the projection of the tool profile in the form of its relative movements with respect to the object. The elements of the machine tool undergo constant wear during the machining process, it is therefore important to recognize the effects of their influence on the surface's irregularities. Amplitude-frequency analysis of lateral profiles has...
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Robust-adaptive dynamic programming-based time-delay control of autonomous ships under stochastic disturbances using an actor-critic learning algorithm
PublikacjaThis paper proposes a hybrid robust-adaptive learning-based control scheme based on Approximate Dynamic Programming (ADP) for the tracking control of autonomous ship maneuvering. We adopt a Time-Delay Control (TDC) approach, which is known as a simple, practical, model free and roughly robust strategy, combined with an Actor-Critic Approximate Dynamic Programming (ACADP) algorithm as an adaptive part in the proposed hybrid control...
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Lamb wave-based monitoring of shear failure of an adhesive lap joint
PublikacjaThe paper presents a study on the elastic wave propagation in adhesive joints of steel plates subjected to tensile loading. A single lap joint was chosen for analysis because of its simplicity and plurality of applications. Experimental investigations consisted of the uniaxial extension of prepared specimens. Force and displacement values were recorded by a testing machine. Simultaneously, guided Lamb waves were excited and signals...
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Non-Contact Temperature Measurements Dataset
PublikacjaThe dataset titled The influence of the distance of the pyrometer from the surface of the radiating object on the accuracy of measurements contains temperature measurements using a selection of four commercially available pyrometers (CHY 314P, TM-F03B, TFA 31.1125 and AB-8855) as a function of the measuring distance. The dataset allows a comparison of the accuracy and measuring precision of the devices, which are very important...
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Treatment of landfill leachate in a constructed free water surface wetland system over a decade – Identification of disturbance in process behaviour and removal of eutrophying substances and organic material
PublikacjaAn 8 ha free water surface wetland system in Örebro, Sweden, which has sediment traps followed by 10 ponds for treatment of landfill leachate in the methanogenic stage, was studied from 2003 to 2012. The wetland was irregularly loaded and the leachate characteristics showed high temporal and spatial variability, so Multivariate Statistical Process Control was chosen as the diagnostic tool for detecting anomalies prior to assessing...
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Corrigendum to “Blood pressure disturbances and endothelial dysfunction markers in children and adolescents with type 1 diabetes” [Atherosclerosis 237 (2014) 129–134]
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Degradation of Kinematic PPP of GNSS Stations in Central Europe Caused by Medium-Scale Traveling Ionospheric Disturbances During the St. Patrick’s Day 2015 Geomagnetic Storm
PublikacjaIn solar cycle 24, the strongest geomagnetic storm took place on March 17, 2015, when the geomagnetic activity index was as high as -223 nT. To verify the impact that the storm had on the Global Navigation Satellite System (GNSS)’s positioning accuracy and precision, we used 30-s observations from 15 reference stations located in Central Europe. For each of them, we applied kinematic precise point positioning (PPP) using gLAB software...
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Control design for slow speed positioning
PublikacjaThe problem under study is a synthesis of position and heading control system for low frequency model of surface vessel described by 3 DOF mathematical model. The recursive vectorial backstepping control design was used to keep fixed position and heading in presence of wave disturbances. The controller has been simulated on computer model of scaled supply vessel. It has been assumed that the actuators produce generalized forces...
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Underwater Navigation Ssystem Based on Doppler Shift – Measurements and Error Estimations
PublikacjaA new acoustic navigation system was developed to determine the position and speed of moving underwater objects such as divers and underwater vehicles. The path of an object and its speed were determined by the Doppler shifts of acoustic signals emitted by a transmitter placed on the object and received by four hydrophones installed at the periphery of the monitored body of water. The position and speed measurements were affected...
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Propagation of Ship-Generated Noise in Shallow Sea
PublikacjaContamination of sea environment by noise and any energy radiated to water constitutes today a problem to which more and more attention is paid, in view, a.o., of consequences of an impact of these factors onto marine fauna. European Union has introduced a directive by which EU countries are made responsible to undertake efforts aimed at reaching a good envirenmental status of European seas by 2020. A main source of underwater...
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Large‐Scale Traveling Ionospheric Disturbances Over the European Sector During the Geomagnetic Storm on March 23–24, 2023: Energy Deposition in the Source Regions and the Propagation Characteristics
PublikacjaMultiple Large-Scale Traveling Ionospheric Disturbances (LSTIDs) are observed in the European sector in both day-time and night-time during the magnetic storm on March 23–24, 2023. The Total Electron Content (TEC) observation from a network of GNSS receivers shows the propagation of LSTIDs with amplitudes between around 0.5 and 1 TECU originating from auroral and polar cusp regions down to southern Europe (35°N) with velocities...
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Decisional-DNA Based Smart Production Performance Analysis Model
Publikacjan order to allocate resources effectively according to the production plan and to reduce disturbances, a framework for smart production performance analysis is proposed in this article. Decisional DNA based knowledge models of engineering objects, processes and factory are developed within the proposed framework. These models are the virtual representation of manufacturing resources, and with help of Internet of Things, are capable...
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PROJEKTOWANIE WIELOWYMIAROWEGO REGULATORA BACKSTEPPING W UKŁADZIE DYNAMICZNEGO POZYCJONOWANIA STATKU
PublikacjaW komercyjnych systemach dynamicznego pozycjonowania statku, pomimo znacznego wzrostu poziomu automatyzacji, wykorzystywane jest nadal sterowanie typu PID. Poprawę jakości procesu pozycjonowania może umożliwić wykorzystanie bardziej efektywnych algorytmów, oferujących zaawansowane nieliniowe techniki sterowania. W artykule przedstawiono zagadnienie projektowania regulatora pozycji i kursu dla układu dynamicznego pozycjonowania...
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Theoretical Model of Acoustic Wave Propagation in Shallow Water
PublikacjaThe work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...
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The influence of external interference on AFM imaging, the use of a protective helmet
Dane BadawczeThis collection is of purely practical importance, showing how the presence of external disturbances can adversely affect the quality of imaging with an atomic force microscope. For this reason, it is also advisable to provide a link to a workshop-like study [1] as well as a huge number of commercial solutions available after entering the keyword "AFM...
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SLIDING MODE-PID FUZZY CONTROLLER WITH A NEW REACHING MODE FOR UNDERWATER ROBOTIC MANIPULATORS
PublikacjaDesign of an accurate and robust controller is a challenging topic in an underwater manipulator control. This is due to hydrodynamic disturbances in underwater environment. In this paper a sliding mode control (SMC) included a PID sliding surface and fuzzy tunable gain is designed. In this proposed controller robustness property of SMC and fast response of PID are incorporated with fuzzy rules to reduce error tracking. In the...
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TIME-AND-SPACE STRUCTURE OF FORCE-DRIVEN RIGID SPHEREWAVEFIELD
PublikacjaThis paper introduces a time-domain, causality-inspired description of a vector-source acoustic wavefield of arbitrary time evolution, where a sphere is a practical realisation of quasi-point contact surface without which a point force would not be able to exert an impact onto non-viscous fluid. At every space location, the resulting acoustic field is described by a pair of physical variables characterising the time evolution of...
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Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
PublikacjaDifferent non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely,...
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Tracking of the broadband source of the underwater noise in the very shallow water conditions
PublikacjaThe paper contains the result s, both theoretical and experimental , connected with the tracking of the underwater noise source as small ships, pontoon , diver and so on. The pro blem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is take n into account the detection of the sources that move on the surface of the sea or underwater in shallow...
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Coda wave interferometry in monitoring the fracture process of concrete beams under bending test
PublikacjaEarly detection of damage is necessary for the safe and reliable use of civil engineering structures made of concrete. Recently, the identification of micro-cracks in concrete has become an area of growing interest, especially using wave-based techniques. In this paper, a non-destructive testing approach for the characterization of the fracture process was presented. Experimental tests were made on concrete beams subjected to mechanical...
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First evaluation of wastewater discharge influence on marine water contamination in the vicinity of Arctowski Station (Maritime Antarctica)
PublikacjaIn Antarctica,waste is generatedmainly during scientific research programmes and related logistics. In this study, the impact ofwastewater on the western shore of Admiralty Baywas investigated during austral summer in 2017 and 2019. A range of physicochemical parameters and the presence of selected trace metals, formaldehyde and different groups of surfactants were determined in wastewater coming from Arctowski Station and in nearby coastal...
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Synteza układu sterowania statkiem morskim dynamicznie pozycjonowanym w warunkach niepewności
PublikacjaNiniejsza monografia obejmuje zagadnienia związane z syntezą układu dynamicznego pozycjonowania statku w środowisku morskim z zastosowaniem wybranych nieliniowych metod sterowania. W ramach pracy autorka rozważała struktury sterowania z zastosowaniem wektorowej adaptacyjnej metody backstep oraz metod jej pokrewnych, takich jak regulatory MSS (ang. multiple surface sliding), DSC (ang. dynamic surface control), NB (ang. neural backstepping)....
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MAKING OF FERROMAGNETIC ELLIPTICAL SHELL IN TRANSVERSE MAGNETIC
PublikacjaA ferromagnetic object, located in the Earth’s magnetic field, changes its distribution. Through measuring such disturbances, one can locate the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, and its task is to eliminate the disturbances in the distribution of the Earth’s magnetic field.
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Multifrequency self-optimizing narrowband interference canceller
PublikacjaThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of a linear stable plant, is considered. It is assumed that disturbance is a multifrequency narrowband signal, and that system output is contaminated with wideband noise. It is not assumed that the reference signal is available. Two disturbance cancelling schemes are proposed, one for disturbances with unrelated frequency components, and...
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On cooperative image denoising
PublikacjaIn this paper we suggest how several competing image denoising algorithms, differing in design parameters, or even in design principles, can be combined together to yield a better and more reliable denoising algorithm. The proposed fusion mechanism allows one to combine practically all kinds of noise reduction tools. It also allows one to account for the distribution of measurement noise, and in particular - to cope with heavy-tailed...
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Static Series and Shunt-series PE Voltage-quality Controllers
PublikacjaAs presented in the Chap. 7 static shunt power electronics (PE) voltage-quality controllers protect the utility electrical system from the unfavorable impact of customer loads. Shunt controllers, as shown in Chap. 6, are recommended mainly for mitigation of the causes of disturbances, and not their effects in distanced nodes of a power-electronics system. In the case when reduction of disturbances effects is required, which leads...
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Easy recipes for cooperative smoothing
PublikacjaIn this paper we suggest how several competing signal smoothers, differing in design parameters, or even in design principles, can be combined together to yield a better and more reliable smoothing algorithm. The proposed heuristic, but statistically well motivated, fusion mechanism allows one to combine practically all kinds of smoothers, from simple local averaging or order statistic filters, to parametric smoothers designed...
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On noncausal identification of nonstationary stochastic systems
PublikacjaIn this paper we consider the problem of noncausal identification of nonstationary,linear stochastic systems, i.e., identification based on prerecorded input/output data. We show how several competing weighted least squares parameter smoothers, differing in memory settings, can be combined together to yield a better and more reliable smoothing algorithm. The resulting parallel estimation scheme automatically adjusts its smoothing...
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Rotor-Flux Vector based Observer of Interior Permanent Synchronous Machine
PublikacjaThe sensorless control system of the interior permanent magnet machine is considered in this paper. The control system is based on classical linear controllers. In the machine, there occurs non-sinusoidal distribution of rotor flux together with the slot harmonics, which are treated as the control system disturbances. In this case, the classical observer structure in the (d-q) is unstable for the low range of rotor speed resulting...
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The power spectral density of audible noise and electric disturbances in ship’s electrical drive systems with frequency converters
Dane BadawczeThe presented dataset is part of research focusing on the impact of the ship's electrical drive systems with frequency converters on vibrations and the level of audible noise on ships.
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The AC motor voltage and audible noise waveforms in ship’s electrical drive systems with frequency converters
Dane BadawczeThe presented dataset is part of research focusing on the impact of the ship's electrical drive systems with frequency converters on vibrations and the level of audible noise on ships.
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The conducted immunity test of a power supply unit in accordance with EMC standards
Dane BadawczeThe dataset presents a result of measurements that are a part of immunity tests to conducted disturbances, induced by radio-frequency fields. The immunity tests were carried out on the mains cable of the DF1723003TC NDN power supply. Tests of immunity of electronic systems to conducted disturbances in the frequency range from 150 kHz to 230 MHz are...
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Efficient Usage of Dense GNSS Networks in Central Europe for the Visualization and Investigation of Ionospheric TEC Variations
PublikacjaThe technique of the orthogonal projection of ionosphere electronic content variations for mapping total electron content (TEC) allows us to visualize ionospheric irregularities. For the reconstruction of global ionospheric characteristics, numerous global navigation satellite system (GNSS) receivers located in different regions of the Earth are used as sensors. We used dense GNSS networks in central Europe to detect and investigate...
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Multichannel self-optimizing narrowband interference canceller
PublikacjaThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. No reference signal is assumed to be available. The proposed feedback controller is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. The algorithm consists of two loops:...
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Multiple-channel frequency-adaptive active vibration control using SONIC
PublikacjaSONIC (self-optimizing narrowband interference canceller) is an acronym of a new approach to rejection of sinusoidal disturbances acting at the output of a discretetime stable linear plant with unknown and possibly timevarying dynamics. The paper presents two frequency-adaptive extensions of the multivariate SONIC algorithm. The efficacy of the proposed solutions is tested using our laboratory-scale active vibration control plant.
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An improved frequency estimator for an adaptive active noise control scheme
PublikacjaAn improved frequency tracker is proposed for the recently introduced self optimizing narrowband interference canceller (SONIC). The scheme is designed for disturbances with quasi-linear frequency modulation and, under second-order Gaussian random-walk assumption, can be shown to be statistically efficient. One real-world experiment and several simulations show that a considerable improvement in disturbance rejection may be achieved...
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Wavelet-based denoising method for real phonocardiography signal recorded by mobile devices in noisy environment
PublikacjaThe main obstacle in development of intelligent autodiagnosis medical systems based on the analysis of phonocardiography (PCG) signals is noise. The noise can be caused by digestive and respiration sounds, movements or even signals from the surrounding environment and it is characterized by wide frequency and intensity spectrum. This spectrum overlaps the heart tones spectrum, which makes the problem of PCG signal filtrating complex....
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A Novel Speed Observer for Doubly-Fed Induction Generator
PublikacjaThe purpose of this paper is to show a new state observer for doubly-fed generator. A proposed z-type observer algorithm based on mathematical model of doubly fed generator with additional variables treated as a disturbances has been used. A nonlinear multiscalar control method has been used to control active and reactive power of the generator. All analyses were verified by simulations and experiments tests.
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The conducted immunity test of an AC adaptor in accordance with EMC standards
Dane BadawczeThe dataset presents a result of measurements that are a part of immunity tests to conducted disturbances, induced by radio-frequency fields. The immunity tests were carried out on the mains cable of the ac adaptor PHILIPS DC power supply SBC 6654. Tests of immunity of electronic systems to conducted disturbances in the frequency range from 150 kHz...
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Reception of GNSS Signals Under Jamming Conditions
PublikacjaThe article focuses on performance of Global Navigation Satellite System receivers in environment where intentional interference is present. First part is a general description of GNSS systems. Secondly, types of positioning service disturbances are specified. In the third part authors present a scheme of measurement stand which is used to evaluate the influence of interference on reception of navigation signals. Next, research...
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Multichannel self-optimizing active noise control scheme
PublikacjaThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. The proposed cancellation scheme is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. In the important benchmark case - for disturbances with randomwalk-type amplitude...
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Economic crisis in Croatia
PublikacjaCroatia is becoming the 28th member of the European Union on July 1st, 2013. Croatia has gone a long way from a socialistic republic to an independent country recognized as one of the economic tigers of the Western Balkans in the first decade of the 21st century. Croatia has been hit by a global crisis which turned out to be a huge external shock for the region of the Western Balkans. Although it does not enter the economy through...
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Dynamic mass measurement in checkweighers using a discrete time-variant low-pass filter
PublikacjaConveyor belt type checkweighers are complex mechanical systems consisting of a weighing sensor (strain gauge load cell, electrodynamically compensated load cell), packages (of different shapes, made of different materials) and a transport system (motors, gears, rollers). Disturbances generated by the vibrating parts of such a system are reflected in the signal power spectra in a form of strong spectral peaks, located usually in...
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Local dynamics of fluids and dielectrics as the foundation of signal-carrying wave properties
PublikacjaThis paper develops an original approach to fundamental problems of classical linear acoustics and electromagnetics, proving a crucial role of doubly-dynamic local properties of a propagation medium in supporting wave-like fields able to carry information signals. The proof is composed of two steps concerning, subsequently, fluid acoustics and dielectric electromagnetics. The first step consists in complementing a common, practically...
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Underfrequency Load Shedding: An Innovative Algorithm Based on Fuzzy Logic
PublikacjaIn contemporary power systems, the load shedding schemes are typically based on disconnecting a pre-specified amount of load after the frequency drops below a predetermined value. The actual conditions at the time of disturbance may largely dier from the assumptions, which can lead to non-optimal or ineective operation of the load shedding scheme. For many years, increasing the eectiveness of the underfrequency load shedding (UFLS)...
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Design of optimal state feedback controller with observer for multidimensional electrical system
PublikacjaFrom the control point of view, two-input-two-output RC electrical system is a linear and multidimensional system. In this paper, integral control and closed-loop observer are verified whether they can be used and designed. To verify this, Kalman tests are made. These structures are presented and discussed. Integral Control is tested with some base disturbances impact and checked whether it can handle them. The estimated values...
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RENOVATION OF ARCHIVE AUDIO RECORDINGS USING SPARSE AUTOREGRESSIVE MODELING AND BIDIRECTIONAL PROCESSING
PublikacjaThe paper presents a new approach to elimination of broadband noise and impulsive disturbances from archive audio recordings. The proposed adaptive Kalman-like algorithm, based on a sparse autoregressive model of the audio signal, simultaneously detects noise pulses, interpolates the irrevocably distorted samples and performs signal smoothing. It is shown that bidirectional (forward-backward) processing of the archive signal improves...
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A new approach to active noise and vibration control - [Part II: unknown frequency case]
PublikacjaThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown and possibly timevarying 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. It is not assumed that a...
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Research of the changeability of the vessels traffic intensity of inland waterways – case study for Lower Vistula
PublikacjaThe article presents an analysis of the changeability of traffic intensity of inland waterway vessels in the Vistula Delta. The concept of traffic intensity was defined, traffic flows and disturbances were identified in the studied area. The characteristics of the inland waterway traffic model are presented. The results of the analysis indicate the need to carry out modernization of inland waterways for the needs of inland waterway...