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Wyświetlanie 1-15 z 1199
Tytuł:
2-D lossless FIR filter design using synthesis of the paraunitary transfer function matrix
Autorzy:
Wawryn, Krzysztof
Poczekajło, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/24988510.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
lossless system
paraunitary transfer function matrix
FIR filter
embedding method
Opis:
A synthesis method for designing two-dimensional lossless finite impulse response (FIR) filters for various digital signal processing tasks is proposed. The synthesis method is based on using a 2-D embedding approach to obtain the paraunitary transfer function matrix of the lossless FIR filter. The elements of the paraunitary transfer function matrix are the transfer function of a given lossy FIR structure and the transfer functions for its complementary structures. The embedding method is used to design complementary FIR filter structures for several known lossy FIR filters. The lossless FIR filter matrix obtained in this article has a size of 3 × 1 and satisfies the paraunitary conditions. The conditions are described by a set of nonlinear equations. A modified Newton method is used to solve this set of equations. The proposed design method is used to determine the lossless structures of two-dimensional FIR filters for various digital processing tasks.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2023, 33, 4; 673--686
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D Synthetic Aperture Imaging Method in Spectrum Domain for Low-Cost Portable Ultrasound Systems
Autorzy:
Tasinkiewicz, Jurij
Powiązania:
https://bibliotekanauki.pl/articles/31339771.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ultrasound imaging
matrix transducer
delay-and-sum
Fourier transform
synthetic aperture
Opis:
Portable, hand-held ultrasound devices capable of 3D imaging in real time are the next generation of the medical imaging apparatus adapted not only for professional medical stuff but for a wide group of less advanced users. Limited power supply capacity and the relatively small number of channels used for the ultrasound data acquisition are the most important limitations that should be taken into account when designing such devices and when developing the corresponding image reconstruction algorithms. The aim of this study was to develop a new 3D ultrasound imaging method which would take into account the above-mentioned features of the new generation of ultrasonic devices – low-cost portable general access scanners. It was based on the synthetic transmit aperture (STA) method combined with the Fourier spectrum domain (SD) acoustic data processing. The STA using a limited number of elements in transmit and receive modes for ultrasound data acquisition allowed both aforementioned constraints to be obeyed simultaneously. Moreover, the computational speed of the fast Fourier transform (FFT) algorithm utilized for the ultrasound image synthesis in the spectrum domain makes the proposed method to be more competitive compared to the conventional time domain (TD) STA method based on the delay-and-sum (DAS) technique, especially in the case of 3D imaging in real time mode. Performance of the proposed method was verified using numerical 3D acoustic data simulated in the Field II program for MATLAB and using experimental data from the custom design 3D scattering phantom collected by means of the Verasonics Vantage 256™ research ultrasound system equipped with the dedicated 1024-element 2D matrix transducer. The method proposed in this paper was about 80 times faster than its counterpart based on the time domain synthetic transmit aperture (TD-STA) approach in the numerical example of a single 3D ultrasound image synthesized from 4 partial images each containing 64 × 64 × 512 pixels. It was also shown that the acceleration of the image reconstruction was achieved at the cost of a slight deterioration in the image quality assessed by the contrast and contrast-to-noise ratio (CNR).
Źródło:
Archives of Acoustics; 2023, 48, 4; 559-572
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
[tłum.] David Chalmers, Matriks jako metafizyka
[transl.] David Chalmers, The Matrix as Metaphysics
Autorzy:
Chalmers, David
Jarocki, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/488170.pdf
Data publikacji:
2015
Wydawca:
Katolicki Uniwersytet Lubelski Jana Pawła II. Towarzystwo Naukowe KUL
Tematy:
matriks
metafizyka
sceptycyzm
mózg w kadzi
matrix
metaphysics
skepticism
brain in a vat
Źródło:
Roczniki Filozoficzne; 2015, 63, 4; 187-229
0035-7685
Pojawia się w:
Roczniki Filozoficzne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A 2D system approach to the design of a robust modified repetitive-control system with a dynamic output-feedback controller
Autorzy:
Zhou, L.
She, J.
Zhou, S.
Powiązania:
https://bibliotekanauki.pl/articles/330403.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
repetitive control
dynamic output feedback
two dimensional system
singular value decomposition
linear matrix inequality
sterowanie powtarzalne
sprzężenie zwrotne dynamiczne
system dwuwymiarowy
liniowa nierówność macierzowa
Opis:
This paper is concerned with the problem of designing a robust modified repetitive-control system with a dynamic output feedback controller for a class of strictly proper plants. Employing the continuous lifting technique, a continuous-discrete two-dimensional (2D) model is built that accurately describes the features of repetitive control. The 2D control input contains the direct sum of the effects of control and learning, which allows us to adjust control and learning preferentially. The singular-value decomposition of the output matrix and Lyapunov stability theory are used to derive an asymptotic stability condition based on a Linear Matrix Inequality (LMI). Two tuning parameters in the LMI manipulate the preferential adjustment of control and learning. A numerical example illustrates the tuning procedure and demonstrates the effectiveness of the method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2014, 24, 2; 325-334
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Bayesian Approach to Matrix Balancing: Transformation of Industry-Level Data under NACE Revision
Autorzy:
Boratyński, Jakub
Powiązania:
https://bibliotekanauki.pl/articles/2076451.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
matrix balancing
Bayesian inference
NACE revision
transformation matrix
multi-sector modelling
Opis:
We apply Bayesian inference to estimate transformation matrix that converts vector of industry outputs from NACE Rev. 1.1 to NACE Rev. 2 classification. In formal terms, the studied issue is a representative of the class of matrix balancing (updating, disaggregation) problems, often arising in the field of multi- sector economic modelling. These problems are characterised by availability of only partial, limited data and a strong role for prior assumptions, and are typically solved using bi-proportional balancing or cross-entropy minimisation methods. Building on Bayesian highest posterior density formulation for a similarly structured case, we extend the model with specification of prior information based on Dirichlet distribution, as well as employ MCMC sampling. The model features a specific likelihood, representing accounting restrictions in the form of an underdetermined system of equations. The primary contribution, compared to the alternative, widespread approaches, is in providing a clear account of uncertainty.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2016, 4; 219-239
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A COMPARATIVE EMPIRICAL ANALYSIS OF FINANCIAL DEVELOPMENT INDICATORS BETWEEN TRANSITION ECONOMIES AND DEVELOPED ONES
Autorzy:
Karapici, Amanda
Karapici, Elton
Powiązania:
https://bibliotekanauki.pl/articles/452935.pdf
Data publikacji:
2016
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
economy in transition
financial sector development
economic growth
4x2 matrix
Opis:
This paper carries out a comparative analysis of the degree of financial development between transition economies and developed ones based on variables that indicate the direct and indirect degree of financial development. To determine the way the financial systems works and the level of its development, the authors have taken into account four general characteristics of financial institutions and financial markets which were measured for the financial institutions (mainly banks, which are the most important financial institutions in most economies in transition, insurance companies and other financial institutions) as well as for the financial markets, thus leading to a 4x2 matrix of the main characteristics of the financial system. The analysis was developed based on the data found on the Global Financial Development database of the World Bank. Empirical data and authors’ analysis were used to characterize and compare financial systems between countries with economies in transition and developed countries for the years 2008 – 2011. The year 2011 was the last year of available qualitative data for many countries in the Balkan Region such as Albania, Kosovo and Macedonia.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2016, 17, 4; 69-80
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparative Study of Tribological Behavior of Moglice and DK-6(PT) Composites
Autorzy:
Pashechko, Mykhailo
Ishchenko, Аnatoliy
Radionenko, Aleksandr
Kindrachuk, Myroslav
Tisov, Oleksandr
Powiązania:
https://bibliotekanauki.pl/articles/2022309.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
polymer matrix composites
friction coefficient
wear
tribometer
hardness
Opis:
Authors have produced new polymer-based composite material DK-6(PT) for substitution of Moglice (Diamant) polymer. We manufactured and used sliding-friction test apparatus (pin-on-disc) capable of testing three specimens simultaneously, much reducing time for the test. The monitoring of the material curing process and the Shore hardness test indicate minor difference from reference material. Measurements were carried out during the curing period, since it is important to know change in this parameter over time. The wear test proved that DK-6(PT) composite in the long-time test has good wear resistance: over 80 km of the friction path, the wear loss of both materials is approximately the same. Furthermore, the friction factor of DK-6(PT) is 5–10% less than that of Moglice. Thus, the studied new polymeric composite may compete with well-known material Moglice and significantly cut the expenses for reconditioning of worn slide ways of metal working equipment.
Źródło:
Advances in Science and Technology. Research Journal; 2022, 16, 1; 149-157
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A computation algorithm for Strassens matrix multiplication
Algorytm obliczania iloczynu macierzowego Strassena
Autorzy:
Tariov, A.
Gliszczyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/154595.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
iloczyn macierzowy Strassena
szybkie algorytmy
Strassen's matrix multiplication
fast algorithms
Opis:
In the work the vectorized algorithm for Strassen's matrix product calculating is presented. Unlike the proposed in other works "some recommendations" relating to the Strassen's matrix multiplication implementation, we offer specific computational procedures that allow correctly describe the entire sequence of transformations needed to obtain the final result. The proposed algorithm can be successfully applied to accelerate calculations in the FPGA-based platforms.
W pracy został przedstawiony wektoryzowany algorytm wyznaczenia iloczynu macierzowego Strassena. W odróżnieniu od poruszanych w innych publikacjach wybranych uwag dotyczących realizacji metody Strassena w niniejszej pracy zaproponowane są konkretne procedury, opisujące cały proces obliczeniowy i pozwalające na podstawie wykonania skończonej liczby etapów przetwarzania danych wejściowych otrzymać wynik końcowy. Została roztrząśnięta synteza proponowanego algorytmu oraz pokazana postać stosownego grafu przepływowego dla przykładu mnożenia macierzy drugiego rzędu. Zaproponowany algorytm może być sukcesywnie zastosowany do przyspieszonej realizacji obliczeń w platformach FPGA oraz zaimplementowany w wybranym środowisku sprzętowym. Niewątpliwym atutem odróżniającym przedstawione rozwiązanie od tradycyjnego algorytmu jest również brak rekurencji obliczeń, co daje dodatkowy zysk przy zrównolegleniu procesu wyznaczenia iloczynu.
Źródło:
Pomiary Automatyka Kontrola; 2010, R. 56, nr 7, 7; 691-693
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A concept of using static GPS measurements for determination of vertical and horizontal land deformations in the Main and Old City of Gdansk
Autorzy:
Baryła, R.
Oszczak, S.
Koczot, B.
Szczechowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/224428.pdf
Data publikacji:
2007
Wydawca:
Politechnika Warszawska. Wydział Geodezji i Kartografii
Tematy:
pomiary GPS
GPS
odkształcenie poziome
odkształcenie pionowe
Gdańsk
pomiary geodezyjne
GPS measurement
horizontal deformation
vertical deformation
altitude geodetic matrix
engineering surveying
Opis:
The data obtained in the precise levelling performed by the Przedsiębiorstwo Geologiczno - Geodezyjne ,"Geoprojekt - Gdańsk", as well as the material analyses, indicate the need to conduct further observations of dislocations in the Main and Old City of Gdańsk in the next years, in intervals of at least six months, controlled by independent fundamental altitude points. The results of GPS static measurements at reference and check points, conducted during the first year, should be taken as reference values for the measurements conducted in subsequent years. The differences in the results from consecutive years will indicate the existence of vertical and horizontal movements of the earth's surface, where the City of Gdansk is situated. The check points, stabilised with fundamental altitude points, will be used to monitor the settlement of historical tenement houses in Gdańsk. Measurement of horizontal and vertical deformations of the earth surface in the areas where valuable objects of our cultural heritage are situated will make it possible to detect potential threats and to take action to prevent considerable damage.
Źródło:
Reports on Geodesy; 2007, z. 1/82; 17-24
0867-3179
Pojawia się w:
Reports on Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Digitally Controlled Model of an Active Ultrasonic Transducer Matrix for Projection Imaging of Biological Media
Autorzy:
Opieliński, K. J.
Gudra, T.
Pruchnicki, P.
Powiązania:
https://bibliotekanauki.pl/articles/178008.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic projection
active ultrasonic transducer matrix
multielement ultrasonic probe
electrode attachment optimisation
Opis:
The following work presents the idea of constructing a digitally controlled active piezoceramic transducer matrix for ultrasonic projection imaging of biological media in a similar way as in case of roentgenography (RTG). Multielement ultrasonic probes in the form of flat matrices of elementary piezoceramic transducers require attaching a large number of electrodes in order to activate the individual transducers. This paper presents the idea of minimising the number of transducer connections in an active row-column matrix system. This idea was verified by designing a model of a matrix consisting of 16 ultrasonic transducers with electrode attachments optimised by means of electronic switches in rows and columns and miniature transistor switches in the nodes of the matrix allowing to activate selected transducers. The results of measurements and simulations of parameters of the designed matrix show that it is suitable to be used in projection imaging of biological media as a sending probe. In to use the matrix as a universal sending or receiving probe, it was suggested to add further switches that would eliminate the undesired effect of crosstalks in case of switches used for toggling the transducers in the nodes of the matrix.
Źródło:
Archives of Acoustics; 2010, 35, 1; 75-90
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic model of classifier competence based on the local fuzzy confusion matrix and the random reference classifier
Autorzy:
Trajdos, P.
Kurzynski, M.
Powiązania:
https://bibliotekanauki.pl/articles/331025.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
multiclassifier system
cross competence measure
confusion matrix
feedback information
pomiar kompetencji
matryca błędu
informacja zwrotna
Opis:
Nowadays, multiclassifier systems (MCSs) are being widely applied in various machine learning problems and in many different domains. Over the last two decades, a variety of ensemble systems have been developed, but there is still room for improvement. This paper focuses on developing competence and interclass cross-competence measures which can be applied as a method for classifiers combination. The cross-competence measure allows an ensemble to harness pieces of information obtained from incompetent classifiers instead of removing them from the ensemble. The cross-competence measure originally determined on the basis of a validation set (static mode) can be further easily updated using additional feedback information on correct/incorrect classification during the recognition process (dynamic mode). The analysis of computational and storage complexity of the proposed method is presented. The performance of the MCS with the proposed cross-competence function was experimentally compared against five reference MCSs and one reference MCS for static and dynamic modes, respectively. Results for the static mode show that the proposed technique is comparable with the reference methods in terms of classification accuracy. For the dynamic mode, the system developed achieves the highest classification accuracy, demonstrating the potential of the MCS for practical applications when feedback information is available.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 1; 175-189
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A factor graph based genetic algorithm
Autorzy:
Helmi, B. H.
Rahmani, A. T.
Pelikan, M.
Powiązania:
https://bibliotekanauki.pl/articles/330811.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
optimization problem
genetic algorithm
estimation
distribution algorithm
factor graph
matrix factorization
problem optymalizacji
algorytm genetyczny
algorytm estymacji rozkładu
faktoryzacja macierzy
Opis:
We propose a new linkage learning genetic algorithm called the Factor Graph based Genetic Algorithm (FGGA). In the FGGA, a factor graph is used to encode the underlying dependencies between variables of the problem. In order to learn the factor graph from a population of potential solutions, a symmetric non-negative matrix factorization is employed to factorize the matrix of pair-wise dependencies. To show the performance of the FGGA, encouraging experimental results on different separable problems are provided as support for the mathematical analysis of the approach. The experiments show that FGGA is capable of learning linkages and solving the optimization problems in polynomial time with a polynomial number of evaluations.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2014, 24, 3; 621-633
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A factorization of elements in PSL(2, F), where F = Q, R
Autorzy:
Ambrosiewicz, Jan
Powiązania:
https://bibliotekanauki.pl/articles/728836.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
factorization of linear groups
linear groups
matrix representations of groups
sets of elements of the same order in groups
Opis:
Let G be a group and Kₙ = {g ∈ G: o(g) = n}. It is prowed: (i) if F = ℝ, n ≥ 4, then PSL(2,F) = Kₙ²; (ii) if F = ℚ,ℝ, n = ∞, then PSL(2,F) = Kₙ²; (iii) if F = ℝ, then PSL(2,F) = K₃³; (iv) if F = ℚ,ℝ, then PSL(2,F) = K₂³ ∪ E, E ∉ K₂³, where E denotes the unit matrix; (v) if F = ℚ, then PSL(2,F) ≠ K₃³.
Źródło:
Discussiones Mathematicae - General Algebra and Applications; 2000, 20, 2; 159-167
1509-9415
Pojawia się w:
Discussiones Mathematicae - General Algebra and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fault estimation and fault-tolerant control based sliding mode observer for LPV descriptor systems with time delay
Autorzy:
Hamdi, Habib
Rodrigues, Mickael
Rabaoui, Bouali
Benhadj Braiek, Naceur
Powiązania:
https://bibliotekanauki.pl/articles/1838208.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
fault estimation
fault-tolerant control
LPV descriptor system
sliding mode observer
time delay
LMIs
linear matrix inequalities
estymacja błędu
sterowanie odporne na uszkodzenia
sterowanie ślizgowe
liniowa nierówność macierzowa
Opis:
This paper considers the problem of fault-tolerant control (FTC) and fault reconstruction of actuator faults for linear parameter varying (LPV) descriptor systems with time delay. A polytopic sliding mode observer (PSMO) is synthesized to achieve simultaneous reconstruction of LPV polytopic descriptor system states and actuator faults. Exploiting the reconstructed actuator faults and state estimates, a fault-tolerant controller is designed to compensate the impact of actuator faults on system performance by stabilizing the closed-loop LPV delayed descriptor system. Besides, the controller and PSMO gains are obtained throughout the resolution of linear matrix inequalities (LMIs) using convex optimization techniques. The developed PSMO could force the output estimation error to converge to zero in a finite time when the actuators faults are bounded through the reinjection of the output estimation error via a nonlinear switching term. Simulation results applied to a given numerical system are presented to highlight the superiority and effectiveness of the proposed approach.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2021, 31, 2; 247-258
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fault tolerant direct control allocation scheme with integral sliding modes
Autorzy:
Hamayun, M. T.
Edwards, C.
Alwi, H.
Bajodah, A.
Powiązania:
https://bibliotekanauki.pl/articles/330832.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
fault tolerant control
integral sliding mode control
linear matrix inequalities
sterowanie tolerujące uszkodzenia
sterowanie ślizgowe
liniowe nierówności macierzowe
Opis:
In this paper, integral sliding mode control ideas are combined with direct control allocation in order to create a fault tolerant control scheme. Traditional integral sliding mode control can directly handle actuator faults; however, it cannot do so with actuator failures. Therefore, a mechanism needs to be adopted to distribute the control effort amongst the remaining functioning actuators in cases of faults or failures, so that an acceptable level of closed-loop performance can be retained. This paper considers the possibility of introducing fault tolerance even if fault or failure information is not provided to the control strategy. To demonstrate the efficacy of the proposed scheme, a high fidelity nonlinear model of a large civil aircraft is considered in the simulations in the presence of wind, gusts and sensor noise.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 1; 93-102
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 1199

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