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Search results for: SYSTEM IDENTIFICATION METHOD
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Luminescent properties of undoped and Ce3+ doped crystals in Y2O3 Lu2O3 Al2O3 triple oxide system grown by micro-pulling-down method
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An effective method for studying intermolecular interactions in binary liquids with hydrogen bonds: FTIR spectra and ab initio calculations in the N-methylformamide - methanol system
PublicationMolecular complexes in methanol (MeOH)−N-methylformamide (NMF) mixtures were studied based on their FTIR-ATR spectra, to which two methods of analysis were applied: factor analysis and a quantitative version of the difference-spectra method. The mean composition of a complex between NMF and MeOH molecules over the whole range of mixture compositions was determined. Absorbing species differentiated with regard to the interaction...
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Study of Phase Transitions Occurring in a Catalytic System of ncFe-NH3/H2 with Chemical Potential Programmed Reaction (CPPR) Method Coupled with In Situ XRD
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TiO2-C nanocomposite synthesized via facile surfactant-assisted method as a part of less energy-consuming LED-based photocatalytic system for environmental applications
PublicationA novel facile method was used to incorporate carbon into the titania structure. An alternative synthesis method of carbon-doped TiO2 has been proposed by using a widely used and cheap surfactant. During the process, cetyltrimethylammonium bromide plays a dual role, as a morphology modifier and as a carbon source. The presented approach allows obtained TiO2-C nanostructures to be anatase nanocrystals with carbon being deposited...
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Innovative mobile method to determine railway track axis position in global coordinate system using position measurements performed with GNSS and fixed base of the measuring vehicle
PublicationThe shape of the railway track axis and its position in the global coordinate system are essential when defining design parameters of the railway. Correct reconstruction of these quantities is vital for both verifying the compliance of real track parameters with the design and for diagnosing, as all track deformations can also be defined as deviations of real parameters from their design values. The measurements of quantities related...
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Innovative mobile method to determine railway track axis position in global coordinate system using position measurements performed with GNSS and fixed base of the measuring vehicle
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A new nethod for RTS noise of semiconductor devices identification
PublicationIn the paper, a new method, called the noise scatterin pattern method (NSP method), for random telegraph signal noise identyfication in the inherent noise of semiconductor devices is described. A block diagram of a noise measurement system based on the NSP method is presented. Examples of patterns of the NSP method are presented.
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Identification of Fast Time-varying Communication Channels Using the Preestimation Technique
PublicationAccurate identification of stochastic systems with fast-varying parameters is a challenging task which cannot be accomplished using model-free estimation methods, such as weighted least squares, which assume only that system coefficients can be regarded as locally constant. The current state-of-the-art solutions are based on the assumption that system parameters can be locally approximated by a linear combination of appropriately...
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Identification of defected sensors in an array of amperometric gas sensors
PublicationPurpose Amperometric gas sensors are commonly used in air quality monitoring in long-term measurements. Baseline shift of sensor responses and power failure may occur over time, which is an obstacle for reliable operation of the entire system. The purpose of this study is to check the possibility of using PCA method to detect defected samples, identify faulty sensor and correct the responses of the sensor identified as faulty. Design/methodology/approach In...
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Wavelet transform-based approach to defect identification in railway carbon contact strips.
PublicationPantographs of electric rail vehicles are fitted with carbon contact strips, which slide along the contact wire of catenary to provide constant electrical contact. Contact strips are exposed to wear and damages. Using damaged contact strips significantly increases the risk of catenary rupture. Therefore, their technical condition has to be inspected frequently. In previous work a 3D laser scanning system was proposed for recording...
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Mechanical exfoliation and layer number identification of single crystal monoclinic CrCl3
PublicationAfter the recent finding that CrI3, displays ferromagnetic order down to its monolayer, extensive studies have followed to pursue new two-dimensional (2D) magnetic materials. In this article, we report on the growth of single crystal CrCl3 in the layered monoclinic phase. The system after mechanical exfoliation exhibits stability in ambient air (the degradation occurs on a time scale at least four orders of magnitude longer than...
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Soft Sensor Application in Identification of the Activated Sludge Bulking Considering the Technological and Economical Aspects of Smart Systems Functioning
PublicationThe paper presented the methodology for the construction of a soft sensor used for activated sludge bulking identification. Devising such solutions fits within the current trends and development of a smart system and infrastructure within smart cities. In order to optimize the selection of the data-mining method depending on the data collected within a wastewater treatment plant (WWTP), a number of methods were considered, including:...
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Identification of the mechanical properties of the skin by electromechanical impedance analysis of resonant piezoelectric actuator
PublicationThis paper is devoted to the analysis and verification of developed piezoelectric sensor/actuator for measuring the mechanical properties of soft tissues, especially human skin. The key element of the measurement structure is an electromechanical system that uses both the reverse piezoelectric effect (vibration generation – stimulation of the tissues in the appropriate frequency range) and direct piezoelectric effect (system response...
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The process of identification of the track's geometrical layout and the alignment project based on the of satellite measurements
PublicationIn the paper a methodology of restoring of railway track’s geometrical shape in a horizontal plane on the base of conducted mobile satellite surveying was presented. The authors proposed a calculating algorithm for designing the track sections placed in horizontal arcs. In the algorithm an analytical methodology with mathematical formulas is applied. The procedure has an universal character, i.e. provides the possibility of varying...
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A Universal Gains Selection Method for Speed Observers of Induction Machine
PublicationProperties of state observers depend on proper gains selection. Each method of state estimation may require the implementation of specific techniques of finding those gains. The aim of this study is to propose a universal method of automatic gains selection and perform its verification on an induction machine speed observer. The method utilizes a genetic algorithm with fitness function which is directly based on the impulse response...
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Identification of Parameters Influencing the Accuracy of the Solution of the Nonlinear Muskingum Equation
PublicationTwo nonlinear versions of the Muskingum equation are considered. The difference between both equations relates to the exponent parameter. In the first version, commonly used in hydrology, this parameter is considered as free, while in the second version, it takes a value resulting from the kinematic wave theory. Consequently, the first version of the equation is dimensionally inconsistent, whereas the proposed second one is consistent. It...
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ADAPTIVE IDENTIFICATION OF TIME-VARYING IMPULSE RESPONSE OF UNDERWATER ACOUSTIC COMMUNICATION CHANNEL
PublicationThe transmission properties of underwater acoustic communication channel can change dynamically due to the movement of acoustic system transmitter and receiver or underwater objects reflecting transmitted signal. The time-varying impulse response measurement and estimation are necessary to match the physical layer of data transmission to instantaneous channel propagation conditions. Using the correlative measurement method, impulse...
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Discrete identification of continuous non-linear and non-stationary dynamical systems that is insensitive to noise correlation and measurement outliers
PublicationThe paper uses specific parameter estimation methods to identify the coefficients of continuous-time models represented by linear and non-linear ordinary differential equations. The necessary approximation of such systems in discrete time in the form of utility models is achieved by the use of properly tuned `integrating filters' of the FIR type. The resulting discrete-time descriptions retain the original continuous parameterization...
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Investigation on accelerated impedance spectrum measurement method with multisine signal stimulation
PublicationThe paper presents an investigation on the accelerated impedance spectrum measurement method, oriented at parameter identification of technical objects modelled by a linear equivalent circuit, e.g. anticorrosion coatings.The method is based on multisine signal stimulation of an object and response analysis by triangle window filterbanks.It has several advantages, as compared with conventional point-by-point spectrum measurement....
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Experimental bases for the rail track surface damage detection system
PublicationA diagnosis of rail surface is generally based on the classical method of direct assessment and track geometry measurements. Identification and qualification of inequality and damage on the surface rails is depend on the skills and experience person who conducting inspection. In times of increasing exploitation of railways, infrastructure managers decide to use systems supporting the assessment of technical condition of the railways....
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"Shadow" method application within endoscopic examinations of marine engines
PublicationThe paper deals with diagnostic issues concerning endoscopic examinations of the working spaces within marine diesel and gas turbine engines. In the beginning, the endoscopy apparatus being on the laboratory equipment of the Department of Ship Power Plants of Gdansk University of Technology in Poland has been characterized. The endoscopy considerations have been focused on theoretical bases of a digital image processing and especially...
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"Shadow" method application within endoscopic examinations of marine engines
PublicationThe paper deals with diagnostic issues concerning endoscopic examinations of the working spaces within marine diesel and gas turbine engines. In the beginning, the endoscopy apparatus being on the laboratory equipment of the Department of Ship Power Plants of Gdansk University of Technology in Poland has been characterized. The endoscopy considerations have been focused on theoretical bases of a digital image processing and especially...
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Conducted emi identification in power electronic converters : modeling of EMI generation and propagation using circuit simulation and wiener filtering methods.
PublicationThis work presents the circuit simulations and the conventional signal processing technique (Wiener filtering) in order to reconstruct conducted ElectroMagnetic Interferences (EMI), generated and propagated in power electronics converters. In the simulation study, the most accurate presently available models of components of circuit have been used and improved. The proposed Wiener filtering method allows to identifying the transfer...
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3-D finite-difference time-domain modelling of ground penetrating radar for identification of rebars in complex reinforced concrete structures
PublicationThis paper presents numerical and experimental investigations to identify reinforcing bars using the ground penetrating radar (GPR) method. A novel element of the paper is the inspection of different arrangements of reinforcement bars. Two particular problems, i.e. detection of few adjacent transverse bars and detection of a longitudinal bar located over or under transverse reinforcement, have been raised. An attention was also...
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A modelling approach to the transport support for the harvesting and transportation complex under uncertain conditions
PublicationThe article proposes a modelling approach based on structural and parametric identification of the transport support of the harvesting and transportation complex. The efficiency and effectiveness of the proposed methods of structural and parametric identification for the development of a system for harvesting and transportation complex operation has been proved. A mathematical model based on fuzzy logic has been developed. It reflects...
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GPR investigation of the strengthening system of a historic masonry tower
PublicationIn this paper the condition assessment of the strengthening system of a masonry tower was carried out by the GPR method. The study provided unique experimental data acquired during measurements of the reinforced concrete frame embedded in masonry walls. Conducted numerical and experimental investigations were focused on the phenomenon of the diffraction-refraction scattering of the electromagnetic energy. A hyperbola resulting...
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A Framework of A Ship Domain-Based Near-Miss Detection Method Using Mamdani Neuro-Fuzzy Classification
PublicationSafety analysis of navigation over a given area may cover application of various risk measures for ship collisions. One of them is percentage of the so called near- miss situations (potential collision situations). In this article a method of automatic detection of such situations based on the data from Automatic Identification System (AIS), is proposed. The method utilizes input parameters such as: collision risk measure based...
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The consideration to the dynamic systems parameter identification
PublicationIn this paper, a concept for continuous-time dynamic systems parameter identification using modulating function approach is presented. It refers to linear as well as selected non-linear systems. It shows the possibility of direct application without converting differential equation. In particular cases direct application can decrease the amount of computation in non-linear system identification, which generally requires Fourier...
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Towards Robust Identification of Nonstationary Systems
PublicationThe article proposes a fast, two-stage method for the identification of nonstationary systems. The method uses iterative reweighting to robustify the identification process against the outliers in the measurement noise and against the numerical errors that may occur at the first stage of identification. We also propose an adaptive algorithm to optimize the values of the hyperparameters that are crucial for this new method.
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Modelling, Simulation and Optimization of the Wavemaker in a Towing Tank
PublicationThe paper analyses the problem of experimental identification (frequency response), modelling and optimization of the towing tank wavemaker in the Scilab/Xcos environment. The experimental identification of the objects (the towing tank wavemaker placed in the hydrodynamic laboratory of the CTO S.A. Ship Design and Research Centre (CTO)) and the implementation of the models in the simulation environment, enable to perform: 1. tuning...
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A procedure for elastoplastic hardening function identification.
PublicationThe inverse analysis method for identifying a nonlinear hardening function,which governs a plastic yielding of soil and rock materials in the framework of elastoplastic theory is presented. A concept of two stage finite element based on spatial discretization of computational space and hardening function space is introduced. The proposed inverse analysis can be classified as the output least squares method. The Levenberg Marquard...
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Identification of Optocoupler Devices with RTS Noise
PublicationThe results of noise measurements in low frequency range for CNY 17 type optocouplers are presented. The research were carried out on devices with different values of Current Transfer Ratio (CTR). The methods for identification of Random Telegraph Signal (RTS) in noise signal of optocouplers were proposed. It was found that the Noise Scattering Pattern method (NSP method) enables to identify RTS noise as non-Gaussian component...
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On noncausal identification of nonstationary stochastic systems
PublicationIn 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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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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Modal parameters identification with Particle Swarm Optimization
PublicationThe paper presents method of the modal parameters identification based on the Particle Swarm Optimization (PSO) algorithm [1]. The basic PSO algorithm is modified in order to achieve fast convergence and low estimation error of identified parameters values. The procedure of identification as well as algorithm modifications are presented and some simple examples for the SISO systems are provided. Results are compared with the results...
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PCR test for Microsporum canis identification
PublicationMicrosporum canis, for which the natural hosts are cats and dogs, is the most prevalent zoophilic agent causing tinea capitis and tinea corporis in humans. We present here a diagnostic PCR test for M. canis, since its detection and species identification is relevant to the choice of treatment and to the understanding of a probable source of infection. An M. canis-specific PCR was evaluated using 130 clinical isolates of dermatophytes...
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Damage identification by wavelet analysis
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The Methods for RTS Noise Identification
PublicationIn the paper authors present two methods, which allows to identify the RTS noise in noise signal of semiconductor devices. The first one was elaborated to identify the RTS noise and also to estimate the number of its levels. The second one can be used to estimate all of the parameters of Gaussian and non-Gaussian components in the noise signal in a frequency domain.
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Damage identification by wavelet analysis
PublicationW pracy omówiono metodę identyfikacji rodzaju nieciagłości w 1 wymiarowych elementach konstrukcji wykorzystującą pomiar propagacji fali sprężystej i jej analizę metodą transformacji falkowej.
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Identification of models and signals robust to occasional outliers
PublicationIn this paper estimation algorithms derived in the sense of the least sum of absolute errors are considered for the purpose of identification of models and signals. In particular, off-line and approximate on-line estimation schemes discussed in the work are aimed at both assessing the coefficients of discrete-time stationary models and tracking the evolution of time-variant characteristics of monitored signals. What is interesting,...
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Identification of models and signals robust to occasional outliers
PublicationIn this paper estimation algorithms derived in the sense of the least sum of absolute errors are considered for the purpose of identification of models and signals. In particular, off-line and approximate on-line estimation schemes discussed in the work are aimed at both assessing the coefficients of discrete-time stationary models and tracking the evolution of time-variant characteristics of monitored signals. What is interesting,...
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A new look at the statistical identification of nonstationary systems
PublicationThe paper presents a new, two-stage approach to identification of linear time-varying stochastic systems, based on the concepts of preestimation and postfiltering. The proposed preestimated parameter trajectories are unbiased but have large variability. Hence, to obtain reliable estimates of system parameters, the preestimated trajectories must be further filtered (postfiltered). It is shown how one can design and optimize such...
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Identification of hydroacoustic wave sources of ship in motion
PublicationThis paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In...
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Identification of category associations using a multilabel classifier
PublicationDescription of the data using categories allows one to describe it on a higher abstraction level. In this way, we can operate on aggregated groups of the information, allowing one to see relationships that do not appear explicit when we analyze the individual objects separately. In this paper we present automatic identification of the associations between categories used for organization of the textual data. As experimental data...
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Robust identification of quadrocopter model for control purposes
PublicationThe paper addresses a problem of quadrotor unmanned aerial vehicle (so-called X4-flyer or quadrocopter) utility model identification for control design purposes. To that goal the quadrotor model is assumed to be composed of two abstracted subsystems, namely a rigid body (plant) and four motors equipped with blades (actuators). The model of the former is acquired based on a well-established dynamic equations of motion while the...
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On Noncausal Identification of Nonstationary Multivariate Autoregressive Processes
PublicationThe problem of identification of nonstationary multivariate autoregressive processes using noncausal local estimation schemes is considered and a new approach to joint selection of the model order and the estimation bandwidth is proposed. The new selection rule, based on evaluation of pseudoprediction errors, is compared with the previously proposed one, based on the modified Akaike’s final prediction error criterion.
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Local basis function estimators for identification of nonstationary systems
PublicationThe problem of identification of a nonstationary stochastic system is considered and solved using local basis function approximation of system parameter trajectories. Unlike the classical basis function approach, which yields parameter estimates in the entire analysis interval, the proposed new identification procedure is operated in a sliding window mode and provides a sequence of point (rather than interval) estimates. It is...
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On the lower smoothing bound in identification of time-varying systems
PublicationIn certain applications of nonstationary system identification the model-based decisions can be postponed, i.e. executed with a delay. This allows one to incorporate in the identification process not only the currently available information, but also a number of ''future'' data points. The resulting estimation schemes, which involve smoothing, are not causal. Assuming that the infinite observation history is available, the paper...
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The Hough transform in the classification process of inland ships
PublicationThis article presents an analysis of the possibilities of using image processing methods for feature extraction that allows kNN classification based on a ship’s image delivered from an on-water video surveillance system. The subject of the analysis is the Hough transform which enables the detection of straight lines in an image. The recognized straight lines and the information about them serve as features in the classification...
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Building Knowledge for the Purpose of Lip Speech Identification
PublicationConsecutive stages of building knowledge for automatic lip speech identification are shown in this study. The main objective is to prepare audio-visual material for phonetic analysis and transcription. First, approximately 260 sentences of natural English were prepared taking into account the frequencies of occurrence of all English phonemes. Five native speakers from different countries read the selected sentences in front of...