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Search results for: DOA ESTIMATION
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DEVELOPMENT OF A COUPLED NUMERICAL AND EXPERIMENTAL APPROACH TO HYDRODYNAMIC NOISE ESTIMATION
PublicationThe hydroacoustic signature of ships' propellers can be estimated experimentally through measurements of cavitation-induced pressure fluctuations and the corresponding noise distributions at model scale. These measurements need to be performed in a cavitation tunnel under the propellers operating conditions and are quite sensitive and challenging to perform with sufficient accuracy. In comparison, the numerical approach can be...
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Estimation of DC motor parameters using a simple CMOS camera
PublicationDifferent components of control systems for mobile robots are based on dynamic models. In low-cost solutions such a robot is wheeled and equipped with DC motors, which have to be included in the model of the robot. The model is fairly simple but determination of its parameters needs not to be easy. For instance, DC motor parameters are typically identified indirectly using suitable measurements, concerning engine voltage, current,...
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Uncertainty estimation of loop impedance measurement determined by the vector method
PublicationThis article presents a detailed analysis of uncertainty estimation of loop impedance measurement determined by the vector method. The analysis includes the following estimates: resistance variance, voltage variance and time measurement variance. This paper presents a methodology for estimating the combined standard uncertainty of loop impedance by the vector method. The vector method allows to determine loop impedance based on...
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On some approaches to cutting power estimation while wood sawing
PublicationW niniejszym artykule przedstawiono i porównano metody, które mogą być stosowane do szacowania mocy skrawania przy przecinaniu drewna na pilarkach tarczowych. Przy klasycznym podejściu efekty energetyczne procesu przecinania drewna piłami są obliczane na bazie właściwego powierzchniowego oporu skrawania. W internecie dostępne są narzędzia do określania mocy skrawania w postaci oprogramowania dostępnego on-line, przykładowo "Horsepower...
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On adaptive covariance and spectrum estimation of locally stationary multivariate processes
PublicationWhen estimating the correlation/spectral structure of a locally stationary process, one has to make two important decisions. First, one should choose the so-called estimation bandwidth, inversely proportional to the effective width of the local analysis window, in the way that complies with the degree of signal nonstationarity. Too small bandwidth may result in an excessive estimation bias, while too large bandwidth may cause excessive...
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Reliability estimation of underground horizontal fuel tank limit states
PublicationFuel tanks are designed with regard to standard loads and operating conditions. The investigations of the paper show the impact of such factors as tank corrosion and other means on the variation of stress fields and deformation of the underground horizontal tank shell. The introduction of probabilistic methods allows for structural reliability assessment. While the computational time of the entire tank FEM model is high, the preliminary...
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Position Estimation in Corridors Along the Coupled Mode of Radiating Cables
PublicationRadiating 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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Estimation of Average Speed of Road Vehicles by Sound Intensity Analysis
PublicationConstant monitoring of road traffic is important part of modern smart city systems. The proposed method estimates average speed of road vehicles in the observation period, using a passive acoustic vector sensor. Speed estimation based on sound intensity analysis is a novel approach to the described problem. Sound intensity in two orthogonal axes is measured with a sensor placed alongside the road. Position of the apparent sound...
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NUMERICAL ESTIMATION OF HULL HYDRODYNAMIC DERIVATIVES IN SHIP MANOUVERING PREDICTION
PublicationOperating in crowded waterways pose a risk of accidents and disasters due to maneuvering limitations of the ship. In order to predict ship’s maneuvering characteristics at the design stage, model tests are often executed as the most accurate prediction tool. Two approaches can be distinguished here: free running model tests and numerical simulations based on planar motion model with the use of hydrodynamic derivatives obtained...
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Numerical Estimation of Hull Hydrodynamic Derivatives in Ship Maneuvering Prediction
PublicationPrediction of the maneuvering characteristics of the ship at the design stage can be done by means of model tests, computational simulations or a combination of both. The model tests can be realized as direct simulation of the standard maneuvers with the free running model, which gives the most accurate results, but is also the least affordable as it requires very large tank or natural lake, as well as complex equipment of the...
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Estimation of the Ultimate Strength of FRP Strips-to-Masonry Substrates Bond
PublicationFiber-Reinforced Polymers (FRP) were developed as a new method over the past decades due to their many beneficial mechanical properties, and they are commonly applied to strengthen masonry structures. In this paper, the Artificial Neural Network (ANN), K-fold Cross-Validation (KFCV) technique, Multivariate Adaptive Regression Spline (MARS) method, and M5 Model Tree (M5MT) method were utilized to predict the ultimate strength of...
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Estimation of the Maximum Permissible PV Power to be Connected to the MV Grid
PublicationIn recent decades, a significant increase in the share of renewable energy sources in power grids at various voltage levels has been observed. A number of articles have been published highlighting emerging problems in low-voltage grids with a large share of prosumers and in medium- and high-voltage grids to which photovoltaic (PV) plants are connected. The article analyzes the medium-voltage grid in terms of the possibility of...
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DNA REPAIR
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DNA SEQUENCE
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Mobile DNA
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Doxa Comunicacion
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DNA Reporter
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Dog Behavior
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Environmental DNA
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Mitochondrial DNA
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Disposition of Drugs of Abuse and Their Metabolites in Wastewater as a Method of the Estimation of Drug Consumption
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Capacity Estimation of the OFDMA and SC-FDMA Radio Interface for UMTS-LTE
PublicationIn the paper a method of capacity estimation for the UMTS-LTE interface is presented. Both the OFDMA and SC-FDMA technology has been considered. A method of physical resource allocation for users is mentioned and analytical results of theoretical throuhput calculation are described.
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Wiener Filtering Applied to Conducted EMI Estimation in Soft Switching Inverter
PublicationW artykule tym przedstawiono metodę szacowania poziomu zaburzeń elektromagnetycznych przewodzonych generowanych w miekko-przełączalnym falowniku napięcia. Wykorzystano metodę filtracji Wienera, gdzie wykorzystano skończoną liczbę filtrów Wienera jako odzwierciedlenie wszystkich warunków generacji i propagacji zaburzeń. Do określenia transmitancji filtrów wykorzystano przebiegi napięć na zaciskach łączników energoelektronicznych...
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Asynchronous distributed state estimation based on a continuous time stochastic model
PublicationGłównym zadaniem systemu estymacji jest szacowanie stanu obserwowanego obiektu. W rozproszonych wieloczujnikowych systemach estymacji stan obiektu jest estymowany przez pewien zbiór estymatorów lokalnych. Każdy estymator lokalny wykonuje filtrację (np opartą na filtracji Kalmana) danych pochodzących ze skojarzonego z nim czujnika bądź czujników oraz fuzję przetworzonych danych z czujników z danymi pochodzącymi z innych lokalnych...
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Estimation of Housing Demand with Adaptive Neuro-Fuzzy Inference Systems (ANFIS)
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Entropy of water calculated from harmonic approximation: estimation of the accuracy of method
PublicationSome molecular dynamics simulations were performed for liquid TIP4P and SPC water at a constant density (1.00 g/cm(3)) and within the temperature range of 5-90 degrees C. By using harmonic approximation, both the entropy of water S-H and the specific heat c(v) were calculated, and the results were compared to literature data. It was found that harmonic approximation overestimates absolute entropy of TIP4P water by 5.6 J/mol K (similar...
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Speech formant frequency and pitch estimation using instantaneous complex frequency
PublicationW pracy opisany został algorytm estymacji częstotliwości podstawowej oraz częstotliwości środkowych i pasm formantów mowy z wykorzystaniem zespolonej pulsacji chwilowej. W artykule przedstawiono również wyniki działania algorytmu dla polskich samogłosek.
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Estimation of the short-term predictor parameters of speech under noisy conditions
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The use of response surface methodology for reliability estimation of composite engineering structures
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Vector and Triangular Representations of Project Estimation Uncertainty: Effect of Gender on Usability
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Maximum A Posteriori Bayesian Estimation of Chromatographic Parameters by Limited Number of Experiments
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Accuracy improvement of short signal frequency estimation with the use of digital filtration
PublicationW pracy przedstawiono metodę estymacji częstotliwości krótkiej obserwacji zaszumionego sygnału sinusoidalnego. Podstawowy pomiar uzyskuje się za pomocą DFT. Jednak taki pomiar dla krótkich obserwacji cechuje bardzo mała dokładność. W omawianej metodzie pomiar ten jest poprawiany z użyciem specjalnie dobranego filtru cyfrowego. Jakość przedstawianej metody porównano z kilkoma innymi metodami również bazującymi na DFT.
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Numerical estimation of flood zones in the Vistula River valley, Warsaw, Poland
PublicationPrzedstawiono studium dotyczące wyznaczenia stref zagrożenia powodziowego dla miasta Warszawy wskutek wezbrań rzeki Wisły. Do oszacowania zasięgu stref wykorzystano matematyczny model ustalonego przepływu wolnozmiennego oraz numeryczny model terenu doliny rzeki. Do zobrazowania uzyskanych wyników zastosowano system GIS. Na podstawie uzyskanych wyników zidentyfikowano obszary miasta Warszawy narażone na ewentualną powódź oraz odcinki...
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A simple way of increasing estimation accuracy of generalized adaptive notch filters
PublicationGeneralized adaptive notch filters are used for identification/tracking of quasi-periodically varying dynamic systems and can be considered an extension, to the system case, of classical adaptive notch filters. It is shown that frequency biases, which arisein generalized adaptive notch filtering algorithms, can be significantly reduced by incorporating in the adaptive loop an appropriately chosen decision delay. The resulting performance...
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Estimation of optical parameters of highly scattering materials by time-of-flight spectroscopy.
PublicationPrzedstawiono metody wyznaczania podstawowych parametrów materiałów silnie rozpraszających światło na podstawie pomierzonego rozkładu czasu przelotu krótkich impulsów laserowych. W algorytmie wykorzystano metodę Monte Carlo i metodę dyfuzji do opisu propagacji światła. Oszacowano dokładność oszacowywania tych parametrów.
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Estimation of musical sound separation algorithm effectiveness employing neural networks.
PublicationŚlepa separacja dźwięków sygnałów muzycznych zawartych w zmiksowanym materiale jest trudnym zadaniem. Jest to spowodowane tym, że dźwięki znajdujące się w relacjach harmonicznych mogą zawierać kolidujące składowe sinusoidalne (składowe harmoniczne). Ewaluacja wyników separacji jest również problematyczna, gdyż analiza błędu energetycznego często nie odzwierciedla subiektywnej jakości odseparowanych sygnałów. W tej publikacji zostały...
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Indirect Methods of Fish Target Strenght Estimation in Absolute and Logarithmic Domain
PublicationW artykule przedstawiono wyniki estymacji zasobów ryb realizowane w dziedzinie absolutnej (jako estymacja rozproszenia wstecznego) oraz w dziedzinie logarytmicznej (estymacja siły celu).
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Direct estimation of functional and density operators by local operations and classical communication.
PublicationWykazano, że można dokonywać detekcji splątania w paradygmacie odległych laboratoriów. Pokazano, jak można fizycznie zaimplementować strukturalne przybliżenie fizyczne niefizycznego odwzorowania w tym paradygmacie.
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Position and Orientation Estimation in Radio Network With Groups of Locally Synchronized Nodes
PublicationThis article presents a positioning system with groups of locally synchronized nodes. A mobile object is equipped with a group of several synchronized receivers that are able to measure the difference in the time of arrival of signals from reference transmitters. The reference transmitters are synchronized only in local groups, with no global synchronization between groups. It is assumed that the synchronous operation of transmitters...
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Application of commercial microwave links (CMLs) attenuation for quantitative estimation of precipitation
PublicationPrecipitation estimation models are typically sourced by rain gauges, weather radars and satellite observations. A relatively new technique of precipitation estimation relies on the network of Commercial Microwave Links (CMLs) employed for cellular communication networks: the rain-inducted attenuation in the links enables the precipitation estimation. In the paper, it is analysed to what extent the precipitation derived from CML...
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A probabilistic-driven framework for enhanced corrosion estimation of ship structural components
PublicationThe work proposes a probabilistic-driven framework for enhanced corrosion estimation of ship structural components using Bayesian inference and limited measurement data. The new approach for modelling measurement uncertainty is proposed based on the results of previous corrosion tests that incorporate the non-uniform character of the corroded surface of structural components. The proposed framework's basic features are outlined,...
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Estimation of Screw Displacement Pile-Bearing Capacity Based on Drilling Resistances
PublicationThis article presents an engineering, empiricalmethod of estimating the bearing capacity and settlementcharacteristics Q-s of screw displacement piles andcolumns, based on soil resistance encountered during thedrilling to form piles/columns in the ground. The methodwas developed on the basis of correlation analyses of thetest results of 24 piles made during the “DPDT-Auger”research project (Krasiński et al., 2022a). In the proposedmethod,...
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Estimation of Synchronous Generator and AVR Parameters Based on Gradient and Genetic Methods
PublicationThe author present a method for the estimation of selected synchronous generator model and AVR parameters using a gradient and a genetic algorithm. The paper shows an example of model parameter estimation for a turbogenerator, based on the generator voltage time responses obtained during an active and reactive power rejection test
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Evaluation of empirical formulae for estimation of the longitudinal dispersion in activated sludge reactors
PublicationBadania traserowe są szeroko stosowane do oceny hydrauliki reaktorów. Jednak w komorach osadu czynnego interpretacja wyników jest trudna z uwagi na recyrkulacje wewnętrzne i recyrkulację osadu z osadnika. Wzory empiryczne mogą być alternatywną metodą oceny warunków hydraulicznych w komorach. Celem tych badań było sprawdzenie czterech wzorów empirycznych na obliczanie współczynnika dyspersji hydrodynamicznej w oparciu o wyniki badań...
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The use of Response Surface Methodology for reliability estimation of composite engineering structures
PublicationStability loss is one of the key issues in the analysis of shells made of composite materials. This paper aims at finding the variation of the critical or limit value of the load resulting from geometric imperfections. An axially compressed 16-layer cylindrical panel model is considered. The imperfections of the panel are simulated as random fields. The parameters of these fields are used as the basic variables of the reliability...
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Estimation of the amplitude of the signal for the active optical gesture sensor with sparse detectors
PublicationIn this paper we deal with the problem of precise gesture recognition for the active optical proximity sensor with sparse 8 photodiodes. We particularly focus on developing the method of estimating the real, usually not observable, maximum signal value representing maximum intensity of light reflected from an obstacle present in the front of the sensor. Different configurations of the fingers were used as an obstacle. The Monte Carlo...
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Identification of Kinematic Excitation Function by the Modal Coordinates Estimation of the System's Dynamics
PublicationThe paper presents a method of the kinematic excitation courses’ identification in excitation points, based on the car road test acceleration at different measurement points. For the purpose of the laboratory fatigue life investigation of contemporary complex structures (e.g. cars bodies) and components of these structures (i.e. cars roofs), only a few first vibration modes are usually taken into account. During real life tests...
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Energy consumption estimation of low-power devices using an integrating coulombmeter
PublicationThe main problem in designing devices powered with Energy Harvesting is an estimation of energy demand of low-power devices as well as quantity of energy provided by the selected energy transducer in the assumed work conditions. Due to the work characteristic of each block of the device and properties of the measured signal, measurement is not trivial. The paper presents the proposal of the micro-charge measurement device based...
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Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublicationNew 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...
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An Approach to Mean Path Loss Model Estimation for Off-Body Channels
PublicationThis paper presents an approach to estimation of the mean path loss model parameters in off-body Body Area Networks channels. In this approach, the path loss exponent is constrained to a value obtained for the line-of-sight (LoS) propagation in the co-polarised channel, considering a generalised static scenario. The comparison of the goodness of fit between the proposed approach and other approaches, for a set of measurements obtained...