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Wyświetlanie 1-25 z 78
Tytuł:
Reliability, MTTF and Cost Analysis of a Bio Ethanol Plant by Orthogonal Matrix Method
Autorzy:
Sharma, Nitin Kumar
Kumar, Sachin
Powiązania:
https://bibliotekanauki.pl/articles/1159392.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Bio ethanol
MTTF
Orthogonal Matrix Method
Reliability
Opis:
Bio ethanol, Reliability, MTTF, Orthogonal Matrix Method
Źródło:
World Scientific News; 2018, 113; 87-97
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of limiting selected risk types in the municipal waste incineration plant
Autorzy:
Kubińska-Jabcoń, Ewa
Niekurzak, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/1201248.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
risk types
risk management methods
matrix method
FMEA method
Opis:
Risk has become one of the most important categories in the global economy. This term belongs to the most popular phenomena in the economy. Decision making is always connected with risk. It is an inseparable part of human history and there are no man’s actions which cannot be associated with it. The notion of risk is universal: it concerns political, economic and social activities. It takes on specific meaning in the space of economic activity: taking risk entails certain financial consequences. Due to this fact, the essence of risk, methods of its evaluation, as well as its management are the topics of a growing number of publications in various scientific fields. The key problem for an entrepreneur is to first determine sources of risk, to assess its size and the influence it may have on the business, and then–to take action in order to minimize this influence. The article analyses dangers in a municipal waste incineration plant. In incineration plants there are various risks but environmental threats, broadly analysed in this article, belong to the most serious ones. Two independent risk analysis methods have been used for this purpose to determine the most serious threats related to environmental risk and options of counteracting them.
Źródło:
Managerial Economics; 2019, 20, 1; 43-56
1898-1143
Pojawia się w:
Managerial Economics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The J-matrix method: numerical computations
Autorzy:
Syty, P.
Powiązania:
https://bibliotekanauki.pl/articles/1954523.pdf
Data publikacji:
1999
Wydawca:
Politechnika Gdańska
Tematy:
atomic physics
scattering theory
J-matrix method
numerical computations
Opis:
Numerical calculations of scattering phase shifts have been done using J-matrix method (both non-relativistic and relativistic versions). Results of computations for some simple potentials are described and discussed in this paper. In particularly, it has been shown, that successive numerical approximations converge to results obtained using an analytical formula.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1999, 3, 3; 269-276
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mody normalne w magnetycznym łańcuchu
Autorzy:
Dubiel, Ł.
Wal, A.
Kuźma, M.
Powiązania:
https://bibliotekanauki.pl/articles/134887.pdf
Data publikacji:
2015
Wydawca:
Tomasz Mariusz Majka
Tematy:
macierz dynamiczna
wzbudzenie magnetyczne
nonomagnes
Hamiltonian dynamical matrix method
Opis:
W ostatnich latach dużą uwagę zwraca się na badanie dynamiki magnetyzacji w nanoskopowych układach magnetycznych. Wzbudzenia w takich układach mogą mieć charakter tzw. modów normalnych, tj. sinusoidalnych oscylacji wszystkich elementów układu z taką samą częstotliwością. W pracy analizowane są tego typu wzbudzenia dla jednakowych momentów magnetycznych umieszczonych w węzłach łańcucha ograniczonego warunkami brzegowymi Borna-Karmana. W obliczeniach wykorzystano formalizm macierzy dynamicznej pozwalający wyznaczyć zarówno częstotliwości jak i profile obserwowanych modów dla układu swobodnego, tj. niepoddanego działaniu zewnętrznych pól, jak i w obecności stałego pola magnetycznego.
Źródło:
Journal of Education and Technical Sciences; 2015, 2, 1; 27-30
2300-7419
2392-036X
Pojawia się w:
Journal of Education and Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise Elimination of a Multi-tone Broadband Noise with Hybrid Helmholtz Mufflers Using a Simulated Annealing Method
Autorzy:
Chiu, M-C.
Powiązania:
https://bibliotekanauki.pl/articles/176674.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multiple tones
hybrid
Helmholtz
four-pole transfer matrix method
SA method
Opis:
Noise control is essential in an enclosed machine room where the noise level has to comply with the occupational safety and health act. In order to overcome a pure tone noise with a high peak value that is harmful to human hearing, a traditional reactive muffler has been used. However, the traditional method for designing a reactive muffler has proven to be time-consuming and insufficient. In order to efficiently reduce the peak noise level, interest in shape optimization of a Helmholtz muffler is coming to the forefront. Helmholtz mufflers that deal with a pure tone have been adequately researched. However, the shape optimization of multi-chamber Helmholtz mufflers that deal with a broadband noise hybridized with multiple tones within a constrained space has been mostly ignored. Therefore, this study analyzes the sound transmission loss (STL) and the best optimized design for a hybrid Helmholtz muffler under a space- constrained situation. On the basis of the plane wave theory, the four-pole system matrix used to evaluate the acoustic performance of a multi-tone hybrid Helmholtz muffler is presented. Two numerical cases for eliminating one/two tone noises emitted from a machine room using six kinds of mufflers (muffler AF) is also introduced. To find the best acoustical performance of a space-constrained muffler, a numerical assessment using a simulated annealing (SA) method is adopted. Before the SA operation can be carried out, the accuracy of the mathematical model has been checked using the experimental data. Eliminating a broadband noise hybridized with a pure tone (130 Hz) in Case I reveals that muffler C composed of a one- chamber Helmholtz Resonator and a one-chamber dissipative element has a noise reduction of 54.9 (dB). Moreover, as indicated in Case II, muffler F, a two-chamber Helmholtz Resonator and a one-chamber dissipative element, has a noise reduction of 69.7 (dB). Obviously, the peak values of the pure tones in Case I and Case II are efficiently reduced after the muffler is added. Consequently, a successful approach in eliminating a broadband noise hybridized with multiple tones using optimally shaped hybrid Helmholtz mufflers and a simulated annealing method within a constrained space is demonstrated.
Źródło:
Archives of Acoustics; 2012, 37, 4; 489-498
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of a transport applying graph-matrix method
Optymalizacja transportu przy wykorzystaniu metody grafow macierzowych
Autorzy:
Marczuk, A.
Misztal, W.
Powiązania:
https://bibliotekanauki.pl/articles/792896.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
optimization
transport
Vogel's approximation method
graph-matrix method
transport cost
preliminary flow matrix
optimum matrix
transport task
Opis:
The paper presents the procedure for solving a transportation task. The optimization was carried out in two phases. In the first one, a preliminary flow matrix was achieved on a base of the information on the demands and supplies values as well as transport costs, whereas some shifts within the preliminary flow matrix were made. All changes resulted in an optimum matrix, for which Zx function held the lowest possible value. Presented method appeared to be efficient for solving the transportation tasks of particular type.
Celem pracy było przedstawienie postępowania właściwego dla rozwiązywania zadania transportowego. Działania optymalizacyjne przeprowadzono w dwóch etapach. W pierwszym z nich uzyskano wstępną macierz przepływów, na podstawie informacji o wielkości popytów odbiorców i podaży dostawców oraz wartości kosztów przewozów. W drugim etapie dokonano przesunięć we wstępnej macierzy przepływów, uzyskanej w etapie pierwszym. Zmiany te doprowadziły do uzyskania macierzy optymalnej, dla której funkcja Zx przyjęła najniższą wartość. Przedstawiona metoda okazała się być skuteczna przy rozwiązywaniu zadań transportowych określonego typu.
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2011, 11C
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Counting Maximal Distance-Independent Sets in Grid Graphs
Autorzy:
Euler, Reinhardt
Oleksik, Paweł
Skupień, Zdzisław
Powiązania:
https://bibliotekanauki.pl/articles/30146434.pdf
Data publikacji:
2013-07-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
independent set
grid graph
Fibonacci
Padovan numbers
transfer matrix method
Opis:
Previous work on counting maximal independent sets for paths and certain 2-dimensional grids is extended in two directions: 3-dimensional grid graphs are included and, for some/any $ \mathcal{l} \in \mathbb{N} $, maximal distance-$ \mathcal{l} $ independent (or simply: maximal $ \mathcal{l} $-independent) sets are counted for some grids. The transfer matrix method has been adapted and successfully applied
Źródło:
Discussiones Mathematicae Graph Theory; 2013, 33, 3; 531-557
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of mechatronic systems second class by the matrix method
Macierzowa analiza systemów mechatronicznych drugiego rzędu
Autorzy:
Smyczek, J. J.
Powiązania:
https://bibliotekanauki.pl/articles/276320.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
metody macierzowe
teoria systemów
sprzężenie zwrotne
mechatronika
matrix method
mechatronics
Opis:
In the paper an analysis of mechatronic systems by using matrix method has been described. On the base a real matrix method system is presented a model the member: electrics, electronics, mechanics, hydraulics and others in connections with feedback and without them has been examined. In the end an example at a control bus door for this purpose obtaining minimum time control has been presented.
W pracy opisano analizę układów mechatronicznych drugiego rzędu za pomocą metody macierzowej. Wyznaczono oryginalne macierze wypadkowe członów o różnych połączeniach z ujemnym sprzężeniem zwrotnym. Na podstawie realnego systemu mechatronicznego, systemu sterowania drzwiami autobusu, wyznaczono minimalny czas zamykania drzwi.
Źródło:
Pomiary Automatyka Robotyka; 2012, 16, 12; 105-111
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distributed strain reconstruction based on a fiber Bragg grating reflection spectrum
Autorzy:
Detka, M.
Kaczmarek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/220892.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fiber Bragg grating (FBG)
synthesis
distributed sensing
transfer matrix method
Opis:
In this paper, we present a synthesis of the parameters of the fiber Bragg grating (FBG) and the reconstruction of the distributed strain affecting the grating, performed by means of its reflection spectrum. For this purpose, we applied the transition matrix method and the Nelder-Mead nonlinear optimization method. Reconstruction results of the strain profile carried out on the basis of a simulated reflection spectrum as well as measured reflection spectrum of the FBG indicate good agreement with the original strain profile; the profile reconstruction errors are within the single digit percentage range. We can conclude that the Nelder-Mead optimization method combined with the transition matrix method can be used for distributed sensing problems.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 53-64
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Special optical communication filter based on Thue-Morse photonic crystal structure
Autorzy:
Alipour-Banaei, H.
Serajmohammadi, S.
Mehdizadeh, F.
Hassangholizadeh-Kashtiban, M.
Powiązania:
https://bibliotekanauki.pl/articles/173823.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal
Thue-Morse structure
optical filter
transfer matrix method
TMM
Opis:
In this paper we proposed a novel narrowband optical filter for wavelength division multiplexing applications. Due to their high transmission efficiency and very narrowband properties, we used the 5th generation Thue-Morse structure for designing our proposed filter. But novelty of our work is introducing another ID photonic crystal structure as a defect structure into the Thue-Morse structure in order to create pass band inside the photonic band gap of the Thue-Morse structure. All of the simulations and calculations have been done using the transfer matrix method. The most interesting property of this filter is that by increasing the number of the periods of the ordinary 1D photonic crystal, the number of the pass bands increases.
Źródło:
Optica Applicata; 2016, 46, 1; 145-152
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An application of stiffness matrix method to determining of dispersion curves for arbitrary composite materials
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/244021.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
SHM system
multi-layered composites
elastic waves
dispersion curves
stiffness matrix method
Opis:
Nowadays multi-layered composite material is very often applied in different kind of structures, like aircrafts, boats or vehicles. Parts of structures, which are made of these materials, are significantly lighter in comparison with traditional materials, like aluminum or steel alloys. On the other hand, the process of damage creation and evolution in the case of composites is much more complex. Moreover, the damages, which are characteristic for multi-layered materials (matrix cracking, fibre breakage, delaminations), are very difficult to detect at early stage of creation. Hence, there is a need to develop the advanced methods to detect them without destroying tested composite element. One of them is based on analysis of elastic wave propagation through the composite structure. Unfortunately, elastic waves possess strongly dispersive character. Thus, it is necessary to determine dispersion curves for investigated material before the tests in order to appropriate interpretation of received dynamic response of structure. In the case of arbitrary composite materials, it is rather challenging task. In the present article the relatively new, analytical method is applied, namely stiffness matrix method. The fundamental assumptions and the theoretical formulation of this method are discussed. Next numerical examples are presented, namely the dispersion curves are determined for the single orthotropic lamina and multi-layered 'quasi - isotropic' composite plate. The studied plates are made of glass fibres and epoxy resin. In the case of single lamina, the dispersion curves are determined in the parallel, perpendicular and arbitrary direction of waves propagation with respect to the fibre direction. In the case of multi-layered plates, the dispersion curves are computed for one arbitrary direction. Additionally, the phase and group velocities for fundamental modes and fixed excitation frequency are estimated in all directions of waves propagation.
Źródło:
Journal of KONES; 2016, 23, 1; 47-54
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena konkurencyjności międzynarodowej polskiej branży mięsnej w oparciu o koncepcję atrakcyjności i pozycji rynkowej
An assessment of international competitiveness of the polish meat industry based on a market attractiveness and position conception
Autorzy:
Kukuła, Karol
Strojny, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/453688.pdf
Data publikacji:
2010
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
konkurencyjność międzynarodowa
sektor mięsny
metoda macierzowa
international competitiveness
meat industry
matrix method
Opis:
Podmiotem studiów nad konkurencyjnością najczęściej jest przedsiębiorstwo bądź gospodarka narodowa – rzadziej problematyka ta podejmowana jest w odniesieniu do branży. Niniejsze opracowanie koncentruje się na problematyce związanej z konkurencyjnością międzynarodową sektora gospodarki. Badania takie są pomocne w identyfikacji i ocenie znaczenia czynników, które determinują relacje konkurencyjne w branży. Celem badań jest oszacowanie pozycji konkurencyjnej produktów polskiego sektora mięsnego na rynku międzynarodowym. Do kwantyfikacji wykorzystano koncepcję macierzy atrakcyjności i pozycji rynkowej.
Most often a subject of competitiveness studies is either an enterprise or a national economy – uniquely this subject matter is raised with regard to a branch. Present study focuses on issues concerning international competitiveness of a branch of economy. Such investigation is helpful for reason of identification and importance assessment of factors driving competitive relationship within the industry. Te study is aiming at the assessment of competitive position of Polish meat sector products on international market place. For purposes of quantification a concept of market attractiveness and position matrix was used.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2010, 11, 2; 171-180
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of dispersion curves for composite materials with the use of stiffness matrix method
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/386825.pdf
Data publikacji:
2017
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
structural health monitoring
layered composite materials
guided waves
dispersion curves
stiffness matrix method
Opis:
Elastic waves used in Structural Health Monitoring systems have strongly dispersive character. Therefore it is necessary to determine the appropriate dispersion curves in order to proper interpretation of a received dynamic response of an analyzed structure. The shape of dispersion curves as well as number of wave modes depends on mechanical properties of layers and frequency of an excited signal. In the current work, the relatively new approach is utilized, namely stiffness matrix method. In contrast to transfer matrix method or global matrix method, this algorithm is considered as numerically unconditionally stable and as effective as transfer matrix approach. However, it will be demonstrated that in the case of hybrid composites, where mechanical properties of particular layers differ significantly, obtaining results could be difficult. The theoretical relationships are presented for the composite plate of arbitrary stacking sequence and arbitrary direction of elastic waves propagation. As a numerical example, the dispersion curves are estimated for the lamina, which is made of carbon fibers and epoxy resin. It is assumed that elastic waves travel in the parallel, perpendicular and arbitrary direction to the fibers in lamina. Next, the dispersion curves are determined for the following laminate [0°, 90°, 0°, 90°, 0°, 90°, 0°, 90°] and hybrid [Al, 90°, 0°, 90°, 0°, 90°, 0°], where Al is the aluminum alloy PA38 and the rest of layers are made of carbon fibers and epoxy resin.
Źródło:
Acta Mechanica et Automatica; 2017, 11, 2; 121-128
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Risk estimation with the application of the matrix method during the operation of the forklift
Autorzy:
Kozińska, Monika
Radek, Norbert
Rozlach, Andrzej
Mazur, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/1830703.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
matrix method
risk estimation
forklift
operation
metoda macierzowa
szacowanie ryzyka
wózek widłowy
eksploatacja
Opis:
The paper presents issues related to the analysis of the position of a forklift operator.Hazards at the workplace were presented and risk estimation was carried out using the matrix method on the position of a forklift operator. The risk assessment using the matrix method was performed in accordance with the PN-N-18002: 2011 standard. The hazards at the forklift operator's workplace were identified and the occupational risk was assessed. In addition, the employee's personal protective equipment and security factors are also presented, which have been defined to increase the safety of work with forklifts.
Źródło:
System Safety : Human - Technical Facility - Environment; 2021, 3, 1; 337-346
2657-5450
Pojawia się w:
System Safety : Human - Technical Facility - Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the Job Safety Analysis (JSA) Method to Assessment Occupational Risk at the Workplace of the Laser Cutter Operator
Autorzy:
Palega, Michal
Powiązania:
https://bibliotekanauki.pl/articles/2023966.pdf
Data publikacji:
2021-09
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
work environment
threats
occupational risk
occupational health and safety
laser cutout operator
JSA method
matrix method
occupational risk assessment
Opis:
Occupational risk is closely related to work environment. For the same positions, but in different working conditions threats and level of risk can be different. For this also estimating the degree of damage hazard the largest possible should be adopted effects. However, when estimating probability occurrence of threats should include, among others: working conditions, events from the past, or possible employee behavior (in particular those that may be the cause of an accident at work). The source of the above information may be data from statistics or observations of work stations. The article presents the assessment of occupational risk at the position of the laser cutter operator, which was carried out using the Job Safety Analysis (JSA) method. According to this method, occupational risk is determined on the basis of two parameters, i.e.: consequences of C and probability of consequences P. In turn, the probability of consequences is the sum of three factors: frequency of hazard F, probability of event O and avoidability or damage limitation A.
Źródło:
Management and Production Engineering Review; 2021, 13, 3; 40-50
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Loads of Lower Limb Joints During Bicycle Ride
Autorzy:
Stępniewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/386979.pdf
Data publikacji:
2012
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
rower
metoda macierzowa
kończyna dolna
analiza statyczna
jakobian
bicycle
lower limb
movement geometry
matrix method
static analysis
Jacobian
Opis:
This work features a geometric and static analysis of the lower limb during bicycle ride. Basic dimensions are indicated, which are necessary for the description of movement geometry. The simplified flat model was adopted for the analysis. Using the transformation of Denavit-Hartenberg frames, vectors were developed for the position of the rotation axis of the joints in immovable frame. The inverse kinematics problem was solved. The course of displacement changes in the ankle joint was adopted as an angle function for crankset position, based on experimental research results, published in professional literature. The course was approximated with fifth grade polynomial. Joint displacements and loads were established. A sample calculation is presented, illustrating the subject computational algorithm.
Źródło:
Acta Mechanica et Automatica; 2012, 6, 2; 84-87
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Odtwarzanie rozkładu odkształcenia na podstawie widma światłowodowej siatki Bragga
Strain profile reconstruction on the basis of the reflection spectrum of a fiber Bragg grating
Autorzy:
Detka, M.
Kaczmarek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/972194.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
światłowodowa siatka Bragga
odtwarzanie
czujnik rozłożony
metoda macierzy przejścia
fiber Bragg grating (FBG)
reconstruction
distributed sensing
transfer matrix method
Opis:
W artykule przedstawiono syntezę parametrów światłowodowej siatki Bragga (FBG) oraz rekonstrukcję rozłożonego odkształcenia działającego na siatkę na podstawie jej widma odbitego. Wykorzystano do tego celu metodę macierzy przejścia oraz nieliniową metodę optymalizacji Neldera- Meada. Wyniki przeprowadzonych symulacji i odtwarzania profili odkształcenia wskazują na dobrą ich zgodność z oryginalnymi profilami odkształcenie; błędy rekonstrukcji tych profili nie przekraczają pojedynczych procentów. Na tej podstawie stwierdza się, że metodę optymalizacji Neldera-Meada w połączeniu z metodą macierzy przejścia można z powodzeniem stosować w zadaniach miernictwa wielkości rozłożonych.
A synthesis of the fiber Bragg grating (FBG) parameters and reconstruction of the distributed strain affecting the grating performed by means of its reflection spectrum is presented. For this purpose, there are applied the transition matrix method and the Nelder-Mead nonlinear optimization method. The essence of both methods is described. First, simulations of reconstruction of the grating parameters and the linear distributions of compressive strains were performed. The results of these simulations are presented in Section 3. Then the reconstruction of the compressive strain profiles was carried out on the basis of the measured spectrum of the grating. The results of those calculations are given in Section 4. The reconstruction results of the strain profile carried out on the basis of the simulated reflection spectrum and the measured reflection spectrum of the FBG show good agreement with the original strain profile; the profile reconstruction errors are within the single digit percentage range. One can conclude that the Nelder-Mead optimization method combined with the transition matrix method can be used for distributed sensing problems.
Źródło:
Pomiary Automatyka Kontrola; 2013, R. 59, nr 4, 4; 295-299
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
JMATRIX - package for relativistic J-MATRIX calculations in elastic scattering of electrons from model potentials
Autorzy:
Syty, P.
Sienkiewicz, J. E.
Powiązania:
https://bibliotekanauki.pl/articles/1940696.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska
Tematy:
J-matrix method
relativistic
electron elastic scattering
phase shifts
Dirac partial-waves analysis
differential
total
momentum transfer
spin polarization cross sections
Opis:
We present a software package JMATRIX, consisting of two computer codes written in FORTRAN 95 and parallelized with OpenMP, implementing the so-called J-matrix method, applied to elastic scattering of electrons on the radial potential, vanishing faster than the Coulomb potential. In the J-matrix method, the physical scattering problem is replaced by using a well-defined model which is solved analytically. The presented software implements both non-relativistic and relativistic versions of the method, and allows calculations of scattering phase shifts as well as cross sections, in cases when the scattering potential is given through an analytical formula. We performed test calculations for the scattering potential modeled as a truncated Coulomb potential. We show that the numerical phase shifts to converge as we increase the size of the basis used to truncate the scattering potential, and that the method is suitable for calculating the total differential momentum transfer and spin polarization cross sections, using the partial-wave analysis.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2017, 21, 1; 17-42
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Xorshift random number generators from primitive polynomials
Autorzy:
Kumar Bishoi, S.
Narayan Maharana, S.
Powiązania:
https://bibliotekanauki.pl/articles/375858.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
random number generators
Xorshift generator
primitive polynomials
linear feed-back shift registers
multiple-recursive matrix method
generatory liczb losowych
generator Xorshift
Opis:
A class of Xorshift Random Number Generators (RNGs) are introduced by Marsaglia. We have proposed an algorithm which constructs a primitive Xorshift RNG from a given prim- itive polynomial. We also have shown a weakness present in those RNGs and suggested its solution. A separate algorithm also proposed which returns a full periodic Xorshift generator with desired number of Xorshift operations.
Źródło:
Theoretical and Applied Informatics; 2017, 29, 1-2; 1-13
1896-5334
Pojawia się w:
Theoretical and Applied Informatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of global experiences in evaluation of mining zone: Case study the Zohreh River
Zastosowanie globalnych doświadczeń w ocenie strefy wydobycia: Przypadek rzeki Zohreh
Autorzy:
Azarang, Farhang
Shafaei Bejestan, Mahmood
Jafari, Ghazal
Karami, Maryam
Powiązania:
https://bibliotekanauki.pl/articles/293030.pdf
Data publikacji:
2019
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
global experiences
sand and gravel mining
river matrix method
Zohreh River
globalne doświadczenie
metoda macierzowa
rzeka Zohreh
wydobycie piasku i żwiru
Opis:
The materials mining from rivers have a variety of negative and positive effects. Currently, one of the most important issues in river engineering is the proper management of materials mining. In this research, global experiences and international standards for managing sand and gravel mining have been applied to evaluate the mining area in the Zohreh River in Khuzestan province (Iran). One of the evaluation methods in this field is the river matrix method. In this method, which is defined on the basis of river pattern, river characteristics such as river size, site location of materials, associated channel and type of deposit are being considered. In this research, a segment of the Zohreh River between Sardasht Zeydun bridge and Mohseniyeh village in which has good potential for gravel mining was selected and evaluated for river characteristics, mining potential and application of river matrix method. The study indicates that the Zohreh River has a braided pattern in the range. The volume of sediment materials in the target area is about 10 000 m3, the length and width of the mining area are 125 and 80 m respectively, and surface extraction with a maximum depth of 1 m was recommended for extraction of materials. At the end of the research, management solutions and solutions for mining of river materials were presented using various standards.
Pozyskiwanie materiału rzecznego niesie ze sobą wiele negatywnych i pozytywnych skutków. Obecnie jednym z głównych problemów inżynierii rzecznej jest właściwe zarządzanie wydobyciem materiałów. W badaniach wykorzystano globalne doświadczenie i międzynarodowe standardy wydobycia piasku i żwiru do oceny obszaru eksploatacji w rzece Zohreh w prowincji Khuzestan (Iran). Jedną z metod oceny jest metoda macierzowa. W metodzie tej, którą definiuje się na podstawie układu rzeki, bierze się pod uwagę takie cechy rzeki, jak: wielkość, lokalizacja materiału, kanały boczne i rodzaj depozytu. Do badań wybrano odcinek rzeki Zohreh pomiędzy mostem Sardasht Zeydun a wsią Mohseniyeh, gdzie istnieją duże możliwości wydobycia żwiru. Oceniono właściwości rzeki, potencjał wydobywczy i zastosowanie metody macierzowej. Badania wykazały, że rzeka Zohreh na badanym odcinku ma układ wielokorytowy. Objętość materiału osadowego na badanym obszarze wynosi ok. 10 000 m3, długość i szerokość terenu wydobywczego to odpowiednio 125 i 80 m, a zalecana maksymalna głębokość wydobycia materiału wynosi 1 m. W podsumowaniu badań przedstawiono rozwiązania w zakresie wydobycia materiałów rzecznych z uwzględnieniem różnych standardów.
Źródło:
Journal of Water and Land Development; 2019, 41; 19-30
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some closed-form bending formulas for elastically restrained Euler-Bernoulli beams under point and uniformly distributed loads
Autorzy:
Yıldırım, V.
Powiązania:
https://bibliotekanauki.pl/articles/122937.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
Euler-Bernoulli beam
elastic support
transfer matrix method
initial value problem
bending
belka Eulera-Bernoulliego
teoria Eulera-Bernoulliego
metoda macierzy transferu
Opis:
The transfer matrix method based on the Euler-Bernoulli beam theory is employed in order to originally achieve some exact analytical formulas for elastically supported beams under a point force together with uniformly distributed force and uniformly distributed couple moments. Those closed-form formulas can be used in a variety of engineering applications especially at the pre-design stage to get an insight into the response of the structure. Contrary to the classical boundary conditions, it is also observed that the Euler-Bernoulli solutions of a beam with elastic supports are sensitive to the ratio of length to thickness (L/h).
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 3; 97-109
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of the configuration of the fiber-metal laminates on the dispersion relations of the elastic wave modes
Autorzy:
Barski, Marek
Muc, Aleksander
Stawiarski, Adam
Powiązania:
https://bibliotekanauki.pl/articles/2146565.pdf
Data publikacji:
2020
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
FML
fiber metal laminates
GLARE
elastic wave modes
dispersion curves
stiffness matrix method
laminaty metalowo-włókniste
mody fal sprężystych
krzywa dyspersji
metoda macierzy sztywności
Opis:
The current work is devoted to the determination of dispersion curves for elastic wave modes. The studied elastic waves propagate across metal-fiber hybrid composites. In order to solve the problem, special software has been developed with the use of C++. This software works with the MS Windows operating system and the proposed solution is based on the multi-threading mechanism. It makes possible to significantly speed up the calculations. The relatively new approach is used namely the stiffness matrix method. At the very beginning, the dispersion curves are determined for the traditional composite materials of cross-ply configuration, for which the layers are made of glass fiber/epoxy resin and carbon fiber/epoxy resin. The impact of the total number of layers on the dispersion curves is investigated. Next, the influence of the thickness of the layers, which are made of aluminum alloy, on the dispersion characteristic is studied. In the second case, it is assumed that the total thickness of the composite material wall for all cases is identical.
Źródło:
Vibrations in Physical Systems; 2020, 31, 2; art. no. 2020202
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical and numerical identification of lamb waves modes for hybrid composites
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/245066.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
structural health monitoring
elastic waves
dispersion curve
stiffness matrix method
numerical simulations
finite element method
group velocity
fale sprężyste
krzywa dyspersji
symulacje numeryczne
metoda elementów skończonych
prędkość grupowa
Opis:
The current work is devoted to the problem of analytical and numerical identification of fundamental elastic waves' modes, namely symmetric mode S0 and antisymmetric mode A0, in the case of hybrid composite. The investigated material consists of one layer made of aluminum alloy Pa38 and six layers made of glass fabric/epoxy resin. At the very beginning, the dispersion curves are determined with the use of stiffness matrix method. The calculated values of phase velocities are verified by numerical simulation. The semi – analytical finite element method is applied. Next, the numerical simulations of elastic waves propagation are performed. In the studied model, the plane state of strain is assumed. These simulations are carried out with the use of finite element method. The excitation signal is a sine wave modulated by Hanning window. The simulation is repeated for different excitation frequency. The group velocities of wave modes S0 and A0 are estimated and compared with the analytical results. The evaluation of the group velocities is based on the analysis of the appropriate components of displacement. The two different method are employed, namely: cross – correlation method and envelope extraction by Hilbert transform. Generally, the obtained results are in a good agreement. However, the method based on envelope extraction by Hilbert transform provides better correlation between analytical and numerical results. The significant discrepancy is observed in the case of symmetric mode S0 for relatively high values of frequency. It is caused by the dispersion phenomena. The analytical calculations are performed with the use of SCILAB 5.5.2 free software and the numerical simulations are carried out with the use of finite element system ANSYS 13.0.
Źródło:
Journal of KONES; 2017, 24, 1; 31-38
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental verification of similarity criteria for sound absorption of simple metamaterials
Autorzy:
Chojak, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/2202415.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
scale model
scale model test
MES
transfer matrix method
TMM
sound absorption coefficient
model redukcyjny
test modelu redukcyjnego
metoda macierzy przejścia
współczynnik pochłaniania dźwięku
Opis:
The paper concerns the dimensional analysis of simple acoustic metamaterials and its experimental verification in a computer model. Due to their decreased thickness possible because of the thermoviscous losses and sound dispersion that occur in acoustic metamaterials, such structures are gaining popularity, both as sound absorbers and diffusers. This implies the need to find their equivalents to be used at scale - both for modeling interiors with metamaterials and developing more complicated structures. The paper discusses the dimensional analysis performed for a generalized unit cell of a metamaterial with a resonator. The dimensional analysis shows the need for scaling both the geometrical dimensions of the structure and the parameters of the medium - air. The dimensional analysis was derived based on the transfer matrix method and was proven correct with the finite element method model. The paper also discusses the consequences of neglecting the air criteria, which are impossible to be fulfilled. This opens the question of finding new criterial numbers allowing the correct reflection of acoustic metamaterials at scale.
Źródło:
Vibrations in Physical Systems; 2022, 33, 2; art. no. 2022211
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the influence of airflow resistance of layered porous structures on the sound absorption coefficient
Autorzy:
Flach, Artur
Powiązania:
https://bibliotekanauki.pl/articles/24201972.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
airflow resistance
anechoic wedges
transfer matrix method
optimization
PSO
particle swarm optimization
opór przepływu powietrza
kliny akustyczne
metoda macierzy przejścia
optymalizacja
optymalizacja roju cząstek
Opis:
The paper presents the research on the influence of airflow resistance on the sound absorption coefficient of layered porous structures. For the calculation of the sound absorption coefficient, the models of layered sound-absorbing structures were developed with the use of numerical computational models. Using the developed models, optimization was carried out to maximize the average sound absorption coefficient of the structures for a given frequency range. As a result of the research, the dependence of the change in airflow resistance for the successive layers of the material was determined. The results of the work will be particularly useful in the design of wedges used in anechoic chambers.
Źródło:
Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022311
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 78

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