Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Filtering" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-14 z 14
    Tytuł:
    Approximation of the Zakai Equation in a Nonlinear Filtering Problem With Delay
    Autorzy:
    Twardowska, K.
    Marnik, T.
    Pasławska-Południak, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/908197.pdf
    Data publikacji:
    2003
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    stochastic differential equations with delay
    Zakai's equation
    nonlinear filtering
    matematyka
    Opis:
    A nonlinear filtering problem with delays in the state and observation equations is considered. The unnormalized conditional probability density of the filtered diffusion process satisfies the so-called Zakai equation and solves the nonlinear filtering problem. We examine the solution of the Zakai equation using an approximation result. Our theoretical deliberations are illustrated by a numerical example.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2003, 13, 2; 151-160
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A fine-grained arc-consistency algorithm for non-normalized constraint satisfaction problems
    Autorzy:
    Arangú, M.
    Salido, M. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/930140.pdf
    Data publikacji:
    2011
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    problemy z ograniczeniami
    technika filtrowania
    algorytm zgodności
    constraint satisfaction problems
    filtering techniques
    Opis:
    Constraint programming is a powerful software technology for solving numerous real-life problems. Many of these problems can be modeled as Constraint Satisfaction Problems (CSPs) and solved using constraint programming techniques. However, solving a CSP is NP-complete so filtering techniques to reduce the search space are still necessary. Arcconsistency algorithms are widely used to prune the search space. The concept of arc-consistency is bidirectional, i.e., it must be ensured in both directions of the constraint (direct and inverse constraints). Two of the most well-known and frequently used arc-consistency algorithms for filtering CSPs are AC3 and AC4. These algorithms repeatedly carry out revisions and require support checks for identifying and deleting all unsupported values from the domains. Nevertheless, many revisions are ineffective, i.e., they cannot delete any value and consume a lot of checks and time. In this paper, we present AC4-OP, an optimized version of AC4 that manages the binary and non-normalized constraints in only one direction, storing the inverse founded supports for their later evaluation. Thus, it reduces the propagation phase avoiding unnecessary or ineffective checking. The use of AC4-OP reduces the number of constraint checks by 50% while pruning the same search space as AC4. The evaluation section shows the improvement of AC4-OP over AC4, AC6 and AC7 in random and non-normalized instances.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2011, 21, 4; 733-744
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nonlinear image processing and filtering: a unified approach based on vertically weighted regression
    Autorzy:
    Rafajłowicz, E.
    Pawlak, M.
    Steland, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/908044.pdf
    Data publikacji:
    2008
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    filtr nieliniowy
    filtracja obrazu
    regresja ważona
    image filtering
    vertically weighted regression
    nonlinear filters
    Opis:
    A class of nonparametric smoothing kernel methods for image processing and filtering that possess edge-preserving properties is examined. The proposed approach is a nonlinearly modified version of the classical nonparametric regression estimates utilizing the concept of vertical weighting. The method unifies a number of known nonlinear image filtering and denoising algorithms such as bilateral and steering kernel filters. It is shown that vertically weighted filters can be realized by a structure of three interconnected radial basis function (RBF) networks. We also assess the performance of the algorithm by studying industrial images.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2008, 18, 1; 49-61
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Image processing for old movies by filters with motion detection
    Autorzy:
    Skonieczny, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/908449.pdf
    Data publikacji:
    2005
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    filtracja sekwencji obrazu
    detekcja ruchu
    stary film
    image sequence filtering
    motion detection
    old movie
    Opis:
    Old movies suffer from various types of degradation: severe noise, blurred edges of objects (low contrast), scratches, spots, etc. Finding an efficient denoising method is one of the most important and one of the oldest problems in image sequence processing. The crucial thing in image sequences is motion. If the motion is insignificant, then any motion noncompensated method of filtering can be applied. However, if the noise is significant, then this approach gives most often unsatisfactory results. In order to increase the quality of frames, motion compensated filters are usually applied. This is a very time consuming and awkward approach due to serious limitations of optical flow methods. In this paper, a review of various filters with motion detection when applied to the processing of image sequences coming from old movies is presented. These filters are nonlinear and based on the concept of multistage median filtering or mathematical morphology. Some new filters are proposed. The idea of these new filters presented here is to detect moving areas instead of performing full estimation of motion in the sequence and to apply exclusively 2D filters in those regions while applying 3D motion noncompensated filters in static areas, which usually significantly reduces the computational burden.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2005, 15, 4; 481-491
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mathematical methods of signal analysis applied in medical diagnostic
    Autorzy:
    Ciecierski, Konrad A.
    Powiązania:
    https://bibliotekanauki.pl/articles/331189.pdf
    Data publikacji:
    2020
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    decision support system
    signal filtering
    data fusion
    temporal analysis
    system wspomagania decyzji
    filtrowanie sygnału
    fuzja danych
    Opis:
    Digital signal processing, such as filtering, information extraction, and fusion of various results, is currently an integral part of advanced medical therapies. It is especially important in neurosurgery during deep-brain stimulation procedures. In such procedures, the surgical target is accessed using special electrodes while not being directly visible. This requires very precise identification of brain structures in 3D space throughout the surgery. In the case of deep-brain stimulation surgery for Parkinson’s disease (PD), the target area—the subthalamic nucleus (STN)—is located deep within the brain. It is also very small (just a few millimetres across), which makes this procedure even more difficult. For this reason, various signals are acquired, filtered, and finally fused, to provide the neurosurgeon with the exact location of the target. These signals come from preoperative medical imaging (such as MRI and CT), and from recordings of brain activity carried out during surgery using special brain-implanted electrodes. Using the method described in this paper, it is possible to construct a decision-support system that, during surgery, analyses signals recorded within the patient’s brain and classifies them as recorded within the STN or not. The constructed classifier discriminates signals with a sensitivity of 0.97 and a specificity of 0.96. The described algorithm is currently used for deep-brain stimulation surgeries among PD patients.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2020, 30, 3; 449-462
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An SFDI observer-based scheme for a general aviation aircraft
    Autorzy:
    Ariola, M.
    Mattei, M.
    Notaro, I.
    Corraro, F.
    Sollazzo, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/330264.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    model based FDI
    sensor FDI
    extended Kalman filtering
    analytical redundancy
    flight control
    filtracja Kalmana
    redundancja analityczna
    sterowanie lotem
    Opis:
    The problem of detecting and isolating sensor faults (sensor fault detection and isolation—SFDI) on a general aviation aircraft, in the presence of external disturbances, is considered. The proposed approach consists of an extended Kalman observer applied to an augmented aircraft plant, where some integrators are added to the output variables subject to faults. The output of the integrators should be ideally zero in the absence of model uncertainties, external disturbances and sensor faults. A threshold-based decision making system is adopted where the residuals are weighted with gains coming from the solution to an optimization problem. The proposed nonlinear observer was tested both numerically on a large database of simulations in the presence of disturbances and model uncertainties and on input-output data recorded during real flights. In this case, the possibility of successfully applying the proposed technique to detect and isolate faults on inertial and air data sensors, modelled as step or ramp signals artificially added to the real measurements, is shown.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2015, 25, 1; 149-158
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimal state observation using quadratic boundedness: Application to UAV disturbance estimation
    Autorzy:
    Cayero, Julián
    Rotondo, Damiano
    Morcego, Bernardo
    Puig, Vicenç
    Powiązania:
    https://bibliotekanauki.pl/articles/330391.pdf
    Data publikacji:
    2019
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    disturbance estimation
    unmanned aerial vehicle
    optimal estimation
    optimal filtering
    system modelling
    statek powietrzny bezzałogowy
    oszacowanie optymalne
    modelowanie systemowe
    Opis:
    This paper presents the design of a state observer which guarantees quadratic boundedness of the estimation error. By using quadratic Lyapunov stability analysis, the convergence rate and the ultimate (steady-state) error bounding ellipsoid are identified as the parameters that define the behaviour of the estimation. Then, it is shown that these objectives can be merged in a scalarised objective function with one design parameter, making the design problem convex. In the second part of the article, a UAV model is presented which can be made linear by considering a particular state and frame of reference. The UAV model is extended to incorporate a disturbance model of variable size. The joint model matches the structure required to derive an observer, following the lines of the proposed design approach. An observer for disturbances acting on the UAV is derived and the analysis of the performances with respect to the design parameters is presented. The effectiveness and main characteristics of the proposed approach are shown using simulation results.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2019, 29, 1; 99-109
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Model-based techniques for virtual sensing of longitudinal flight parameters
    Autorzy:
    Hardier, G.
    Seren, C.
    Ezerzere, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/330954.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    model based estimation
    fault detection
    virtual sensor
    Kalman filtering
    surrogate modelling
    estymacja modelu
    detekcja uszkodzeń
    sensor wirtualny
    filtracja Kalmana
    Opis:
    Introduction of fly-by-wire and increasing levels of automation significantly improve the safety of civil aircraft, and result in advanced capabilities for detecting, protecting and optimizing A/C guidance and control. However, this higher complexity requires the availability of some key flight parameters to be extended. Hence, the monitoring and consolidation of those signals is a significant issue, usually achieved via many functionally redundant sensors to extend the way those parameters are measured. This solution penalizes the overall system performance in terms of weight, maintenance, and so on. Other alternatives rely on signal processing or model-based techniques that make a global use of all or part of the sensor data available, supplemented by a model-based simulation of the flight mechanics. That processing achieves real-time estimates of the critical parameters and yields dissimilar signals. Filtered and consolidated information is delivered in unfaulty conditions by estimating an extended state vector, including wind components, and can replace failed signals in degraded conditions. Accordingly, this paper describes two model-based approaches allowing the longitudinal flight parameters of a civil A/C to be estimated on-line. Results are displayed to evaluate the performances in different simulated and real flight conditions, including realistic external disturbances and modeling errors.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2015, 25, 1; 23-38
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Automatic speech signal segmentation based on the innovation adaptive filter
    Autorzy:
    Makowski, R.
    Hossa, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/330096.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    automatic speech segmentation
    inter phoneme boundaries
    Schur adaptive filtering
    detection threshold determination
    automatyczna segmentacja mowy
    filtracja adaptacyjna
    określenie progu detekcji
    Opis:
    Speech segmentation is an essential stage in designing automatic speech recognition systems and one can find several algorithms proposed in the literature. It is a difficult problem, as speech is immensely variable. The aim of the authors’ studies was to design an algorithm that could be employed at the stage of automatic speech recognition. This would make it possible to avoid some problems related to speech signal parametrization. Posing the problem in such a way requires the algorithm to be capable of working in real time. The only such algorithm was proposed by Tyagi et al., (2006), and it is a modified version of Brandt’s algorithm. The article presents a new algorithm for unsupervised automatic speech signal segmentation. It performs segmentation without access to information about the phonetic content of the utterances, relying exclusively on second-order statistics of a speech signal. The starting point for the proposed method is time-varying Schur coefficients of an innovation adaptive filter. The Schur algorithm is known to be fast, precise, stable and capable of rapidly tracking changes in second order signal statistics. A transfer from one phoneme to another in the speech signal always indicates a change in signal statistics caused by vocal track changes. In order to allow for the properties of human hearing, detection of inter-phoneme boundaries is performed based on statistics defined on the mel spectrum determined from the reflection coefficients. The paper presents the structure of the algorithm, defines its properties, lists parameter values, describes detection efficiency results, and compares them with those for another algorithm. The obtained segmentation results, are satisfactory.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2014, 24, 2; 259-270
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Asynchronous distributed state estimation for continuous-time stochastic processes
    Autorzy:
    Kowalczuk, Z.
    Domżalski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/331193.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    continuous time
    stochastic processes
    distributed system
    state estimation
    Kalman filtering
    układ ciągły
    układ stochastyczny
    system rozproszony
    estymacja stanu
    filtracja Kalmana
    Opis:
    The problem of state estimation of a continuous-time stochastic process using an Asynchronous Distributed multi-sensor Estimation (ADE) system is considered. The state of a process of interest is estimated by a group of local estimators constituting the proposed ADE system. Each estimator is based, e.g., on a Kalman filter and performs single sensor filtration and fusion of its local results with the results from other/remote processors to compute possibly the best state estimates. In performing data fusion, however, two important issues need to be addressed namely, the problem of asynchronism of local processors and the issue of unknown correlation between asynchronous data in local processors. Both the problems, along with their solutions, are investigated in this paper. Possible applications and effectiveness of the proposed ADE approach are illustrated by simulated experiments, including a non-complete connection graph of such a distributed estimation system.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2013, 23, 2; 327-339
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nonlinear filtering for Markov systems with delayed observations
    Autorzy:
    Calzolari, A.
    Florchinger, P.
    Nappo, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/907856.pdf
    Data publikacji:
    2009
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    filtracja nieliniowa
    proces dyfuzji
    procesy Markova
    stochastyczne równanie różniczkowe
    nonlinear filtering
    jump processes
    diffusion processes
    Markov processes
    stochastic delay differential equation
    Opis:
    This paper deals with nonlinear filtering problems with delays, i.e., we consider a system (X,Y ), which can be represented by means of a system [...], in the sense that [...], where a(t) is a delayed time transformation. We start with X being a Markov process, and then study Markovian systems, not necessarily diffusive, with correlated noises. The interest is focused on the existence of explicit representations of the corresponding filters as functionals depending on the observed trajectory. Various assumptions on the function a(t) are considered.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2009, 19, 1; 49-57
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Robust flat filtering control of a two degrees of freedom helicopter subject to tail rotor disturbances
    Autorzy:
    Sánchez-Meza, Victor-Gabriel
    Lozano-Hernández, Yair
    Gutiérrez-Frías, Octavio
    Lozada-Castillo, Norma
    Luviano-Juárez, Alberto
    Powiązania:
    https://bibliotekanauki.pl/articles/24200696.pdf
    Data publikacji:
    2023
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    flat filtering control
    generalized proportional integral control
    nonlinear system
    tail rotor disturbance
    two degrees of freedom helicopter
    sterowanie całkujące
    układ nieliniowy
    zakłócenia wirnika
    Opis:
    This article deals with modelling and a flatness-based robust trajectory tracking scheme for a two degrees of freedom helicopter, which is subject to four types of tail rotor disturbances to validate the control scheme robustness. A mathematical model of the system, its differential flatness and a differential parametrization are obtained. The flat filtering control is designed for the system control with a partially known model, assuming the non-modelled dynamics and the external disturbances (specially the tail rotor ones) to be rejected by means of an extended state model (ultra-local model). Numerical and experimental assessments are carried out on a characterized prototype whose yaw angle (ψ), given by the z axis, is in free form, while the pitch angle (θ), which results from rotation about the y axis, is mechanically restricted. The proposed controller performance is tested through a set of experiments in trajectory tracking tasks with different disturbances in the tail rotor, showing robust behaviour for the different disturbances. Besides, a comparison study against a widely used controller of LQR type is carried out, in which the proposed controller achieves better results, as illustrated by a performance index.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2023, 33, 4; 521--535
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Novel optimal recursive filter for state and fault estimation of linear stochastic systems with unknown disturbances
    Autorzy:
    Khémiri, K.
    Ben Hmida, F.
    Ragot, J.
    Gossa, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/930170.pdf
    Data publikacji:
    2011
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    filtracja Kalmana
    estymacja stanu
    zakłócenie nieznane
    system liniowy
    system dyskretno-czasowy
    Kalman filtering
    minimum variance estimation
    state estimation
    fault estimation
    unknown disturbances
    linear discrete time systems
    Opis:
    This paper studies recursive optimal filtering as well as robust fault and state estimation for linear stochastic systems with unknown disturbances. It proposes a new recursive optimal filter structure with transformation of the original system. This transformation is based on the singular value decomposition of the direct feedthrough matrix distribution of the fault which is assumed to be of arbitrary rank. The resulting filter is optimal in the sense of the unbiased minimum-variance criteria. Two numerical examples are given in order to illustrate the proposed method, in particular to solve the estimation of the simultaneous actuator and sensor fault problem and to make a comparison with the existing literature results.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2011, 21, 4; 629-637
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    SMAC-FDI: A single model active fault detection and isolation system for unmanned aircraft
    Autorzy:
    Ducard, G. J. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/331366.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    fault detection
    fault isolation
    unmanned aerial vehicle
    Kalman filtering
    computationally efficient diagnosis system
    active fault diagnosis
    artificial excitation system
    detekcja uszkodzeń
    lokalizacja uszkodzeń
    bezzałogowiec
    filtracja Kalmana
    diagnostyka uszkodzeń
    układ wzbudzenia
    Opis:
    This article presents a single model active fault detection and isolation system (SMAC-FDI) which is designed to efficiently detect and isolate a faulty actuator in a system, such as a small (unmanned) aircraft. This FDI system is based on a single and simple aerodynamic model of an aircraft in order to generate some residuals, as soon as an actuator fault occurs. These residuals are used to trigger an active strategy based on artificial exciting signals that searches within the residuals for the signature of an actuator fault. Fault isolation is carried out through an innovative mechanism that does not use the previous residuals but the actuator control signals directly. In addition, the paper presents a complete parameter-tuning strategy for this FDI system. The novel concepts are backed-up by simulations of a small unmanned aircraft experiencing successive actuator failures. The robustness of the SMAC-FDI method is tested in the presence of model uncertainties, realistic sensor noise and wind gusts. Finally, the paper concludes with a discussion on the computational efficiency of the method and its ability to run on small microcontrollers.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2015, 25, 1; 189-201
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-14 z 14

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies