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Wyświetlanie 1-15 z 43
Tytuł:
A new elliptical model of the vocal tract
Autorzy:
Kobus, A.
Kuniszyk-Jóźkowiak, W.
Smołka, E.
Suszyński, W.
Codello, I.
Powiązania:
https://bibliotekanauki.pl/articles/333373.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
model eliptyczny
aparat głosowy
przewidywania liniowe
jąkanie
elliptical model
vocal tract
PARCOR
linear prediction
disfluency
stuttering
Opis:
In this paper a new model of the vocal tract is proposed. It is based on elliptical cylinders. It uses the vocal tract model based on PARCOR coefficients and midsaggital measurements of the voice tube. PARCOR coefficients were obtained from linear prediction coefficients which had been obtained by Levinson-Durbin method. Midsaggital lengths, understood as the height of a real vocal tract, were taken from X-Ray pictures, and they were averaged from the vocal tracts of a few people, who uttered the same vowels. The paper bases on Polish vowels: a,e,o,u,i,y.
Źródło:
Journal of Medical Informatics & Technologies; 2011, 17; 131-139
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A simplified elliptical function solution for coupled nonlinear vibration of multilayer graphene sheets
Autorzy:
Venkatraman, G.
Suji, D.
Powiązania:
https://bibliotekanauki.pl/articles/2086951.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
nonlinear coupled vibration
nonlinear van der Waals force
Multilayer Graphene Sheets
elliptical function
exact solution
Opis:
This paper presents a simple exact solution for coupled nonlinear free vibration analysis of Multilayer Graphene Sheets (MLGS) using elliptical functions. Though elliptical functions are used in nonlinear dynamics, they are employed to find the exact solution of a coupled system for the first time. The nonlinear dynamic equation including geometric nonlinearity and Eringen nonlocal theory is uncoupled by elliptical functions, and exact solutions for simply supported boundary conditions are obtained. The results are compared with the harmonic balance method. The nonlinear frequency of MLGS is studied for its effects with a small scale parameter, and the linear and nonlinear van der Waals force.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 1; 3--16
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analytical-numerical method for calculating the stationary thermal field in electrical systems with elliptical cross-sections
Autorzy:
Gołębiowski, Jerzy
Zaręba, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2128141.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analytical-numerical methods of field theory
elliptical conductors
Poisson's equation
metody teorii pola analityczno-numeryczne
przewodniki eliptyczne
równanie Poissona
Opis:
In this article, an analytical-numerical approach to calculating a stationary thermal field in the elliptical region is presented. The eigenfunctions of the Laplace operator were determined analytically, whereas the coefficients of the eigenfunctions were obtained numerically. The cooling was modeled with 3rd kind (Hankel’s) boundary condition, where the total heat transfer coefficient was the sum of the convective and radiative components. The method was used to analyze the thermal field in an elliptical conductor and a dielectrically heated elliptical column. The basic parameters of these systems, i.e. their steady-state current rating and the maximum charge temperature, were determined. The results were verified using the finite element method and have been presented graphically.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 2; e136738, 1--6
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analytical-numerical method for calculating the stationary thermal field in electrical systems with elliptical cross-sections
Autorzy:
Gołębiowski, Jerzy
Zaręba, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2173609.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analytical-numerical methods of field theory
elliptical conductors
Poisson's equation
metody teorii pola analityczno-numeryczne
przewodniki eliptyczne
równanie Poissona
Opis:
In this article, an analytical-numerical approach to calculating a stationary thermal field in the elliptical region is presented. The eigenfunctions of the Laplace operator were determined analytically, whereas the coefficients of the eigenfunctions were obtained numerically. The cooling was modeled with 3rd kind (Hankel’s) boundary condition, where the total heat transfer coefficient was the sum of the convective and radiative components. The method was used to analyze the thermal field in an elliptical conductor and a dielectrically heated elliptical column. The basic parameters of these systems, i.e. their steady-state current rating and the maximum charge temperature, were determined. The results were verified using the finite element method and have been presented graphically.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 2; art. no. e136738
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of fractional order theory of thermoelasticity in an elliptical disk and associated thermal stresses
Autorzy:
Thakare, S.
Panke, Y.
Hadke, K.
Powiązania:
https://bibliotekanauki.pl/articles/1839826.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
naprężenia termiczne
pochodna Caputo
termosprężystość
elliptical disk
fractional order theory
Caputo derivative
integral transform
thermal stresses
thermal deflection
Opis:
In this article, a time fractional-order theory of thermoelasticity is applied to an isotropic homogeneous elliptical disk. The lower and upper surfaces of the disk are maintained at zero temperature, whereas the sectional heat supply is applied on the outer curved surface. Thermal deflection and associated thermal stresses are obtained in terms of Mathieu function of the first kind of order 2n. Numerical evaluation is carried out for the temperature distribution, Thermal deflection and thermal stresses and results of the resulting quantities are depicted graphically.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 3; 169-180
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aspect of the elliptical field in the screened flat three-phase high current busduct. Part I - In the internal area of the screen
Aspekt pola eliptycznego w ekranowanym płaskim trójfazowym torze wielkoprądowym. Część I - W obszarze wewnętrznym ekranu
Autorzy:
Kusiak, D.
Piątek, Z.
Szczegielniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/376450.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
elliptical field
screened flat three-phase high current busduct
high current busduct
external proximity effect
internal proximity effect
Opis:
The paper shown the elliptical magnetic field in the high current screened busduct in the case of the both the external and internal proximity effect. For the characterisation of complex vector values for such a field it is proposed that the length of the longer ellipse semi axis as indicated by the end of the vector within one period be used. Part I describes of elliptic field in the internal area of the screen of the flat three-phase high current busduct.
W artykule przedstawiono eliptyczne pole magnetyczne występujące w ekranowanym torze wielkoprądowym w przypadku zewnętrznego i wewnętrznego zjawiska zbliżenia. Do charakteryzowania wartości zespolonego wektora takiego pola zaproponowano długość dłuższej półosi elipsy jaką zakreśla koniec tego wektora w ciągu jednego okresu. Część I opisuje pole eliptyczne w obszarze wewnętrznym ekranu trójfazowego płaskiego toru wielkoprądowego.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 69; 127-134
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of danger of long‑term operated coiled tubing failure
Autorzy:
Vytyaz, Oleg
Hrabovskyi, Roman
Bezaniuk, Yarema
Powiązania:
https://bibliotekanauki.pl/articles/1403643.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
coiled tubing failure
stress intensity
external transverse semi‑elliptical crack
Opis:
The power criterion of the resistance to failure of the metal of coiled tubing (CT) was experimentally evaluated. The conditions are defined under which failure is possible during the operation of CT containing an external semi‑elliptical crack. The interconnection of the critical depths of external semi‑elliptical cracks from the ratio of their semiaxes is established. It is shown that, during the course of operation, the external transverse semi‑elliptical crack with the ratio of semiaxes (a/c)i = 1/2 is the most dangerous for coiled tubing. The experimental and calculation procedures are proposed that give us an opportunity to interpret the results of their technical diagnostics in evaluating the conditions under which the failure of flexible pipes containing outer transverse semi‑elliptical cracks is possible during tripping operations.
Źródło:
AGH Drilling, Oil, Gas; 2020, 37, 4; 5-14
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Blank shape optimization on deep drawing of a twin elliptical cup using the reduced basis technique method
Autorzy:
Golshani, M H
Jabbari, A.
Powiązania:
https://bibliotekanauki.pl/articles/957954.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
deep drawing
twin elliptical cup
reduce basic technique
anisotropic
sheet
earring
Opis:
In this project thesis, initial blank shape optimization of a twin elliptical cup to reduce earring phenomenon in anisotropic sheet deep drawing process was studied .The purpose of this study is optimization of initial blank for reduction of the ears height value. The optimization process carried out using finite element method approach, which is coupled with Taguchi design of experiments and reduced basis technique methods. The deep drawing process was simulated in FEM software ABAQUS 6.12. The results of optimization show earring height and, in addition, a number of design variables and time of process can be reduced by using this methods. After optimization process with the proposed method, the maximum reduction of the earring height would be from 21.08 mm to 0.07 mm and also it could be reduced to 0 in some of the directions. The proposed optimization design in this article allows the designers to select the practical basis shapes. This leads to obtain better results at the end of the optimization process, to reduce design variables, and also to prevent repeating the optimization steps for indirect shapes.
Źródło:
Advances in Science and Technology. Research Journal; 2015, 9, 27; 72-77
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contact interaction of rigid stamp and infinite orthotropic plate with close to elliptical hole
Autorzy:
Kotsyuba, A.
Powiązania:
https://bibliotekanauki.pl/articles/387386.pdf
Data publikacji:
2013
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
ciało ortotropowe
metoda numeryczna
naprężenia kontaktowe
orthotropic
elliptical hole
numerical method
contact stresses
Opis:
Numerical method of finding the contact stresses under the stamp of complex shape for the case of orthotropic plates with close to an elliptical hole, which based on constructed in Bozhydarnik et al., (2007) algorithm, is developed. The distribution of contact stresses under the stamp, which shape matches the shape of the hole, is investigated
Źródło:
Acta Mechanica et Automatica; 2013, 7, 4; 230-235
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a Microstrip Filtering Antenna for 4G and 5G Wireless Networks
Autorzy:
Boddu, Ramesh
Deb, Arindam
Roy, Jibendu Sekhar
Powiązania:
https://bibliotekanauki.pl/articles/24200731.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
elliptical microstrip patch antenna
filtering antenna
hairpin bandpass filter
Opis:
The filtering antenna provides both radiation and filtering features and is an important component for the RF front-end of wireless devices. The main function of a filtering antenna is to reject out-of-band signals, thus reducing the interference from adjacent channels. The aim of the present work is to design a 2.6 GHz microstrip filtering antenna for 4G and 5G global mobile services. The filtering antenna is designed using a hairpin bandpass filter integrated with an elliptical microstrip aerial. Good impedance matching is obtained by using appropriate dimensions of the hairpin bandpass filter. The 10 dB return loss bandwidth of the filtering antenna is approx. 5.7%, with the maximum gain for the elliptical filtering antenna of approx. 2.2 dB. Good agreements between the measured and simulated results are obtained for the proposed filtering antenna and the bandwidth covers almost the entire 2.6 GHz band.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 2; 78--83
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of micro protrusions on the performance of elliptical journal bearings operating with couple stress lubricant
Autorzy:
Abass, Basim Ajeel
Mahdi, Mushrek A.
Powiązania:
https://bibliotekanauki.pl/articles/1840900.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
elliptical journal bearing
hydrodynamic lubrication
micro-protrusions
couple-stress lubricant
non-Newtonian fluids
smarowanie hydrodynamiczne
płyny nienewtonowskie
Opis:
Elliptical bearing is characterized by low induced temperature and high stability at higher speed in comparison with the cylindrical journal bearing. The performance of such bearings can be affected by the type of oil used and its surface properties. The main goal of this work is to study the surface micro protrusion effect on the steady state operation of elliptical journal bearing lubricated with couple stress lubricant. The modified Reynolds’ equation to take into account the effects of couple stress lubricant and micro protrusions of the bearing surfaces is solved using finite difference method. The governing equations were solved using a prepared FORTRAN computer program. Pressure distribution, load carrying capacity and coefficient of friction have been studied for a bearing in laminar flow regime. The mathematical model was validated by comparing pressure results for the elliptical bearing of the present work with that obtained by Hussain et al.(1996). The obtained results demonstrate that the lubricant pressure and the load carried by the bearing decrease for the bearing with higher ellipticity factor while the load carried by the bearing increases for the bearing with higher protrusions or when using a couple stress fluid with higher couple stress variable.
Źródło:
Diagnostyka; 2021, 22, 2; 97-104
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Rayleigh number on internal eccentricity in a heated horizontal elliptical cylinder to its coaxial square enclosure
Autorzy:
Bouras, Abdelkrim
Taloub, Djedid
Driss, Zied
Powiązania:
https://bibliotekanauki.pl/articles/1839785.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
konwekcja naturalna
płyn Newtona
liczba Rayleigha
natural convection
newtonian fluid
geometry ratio
Rayleigh number
elliptical cylinder
Opis:
This paper deals with numerical investigation of a natural convective flow in a horizontal annular space between a heated square inner cylinder and a cold elliptical outer cylinder with a Newtonian fluid. Uniform temperatures are imposed along walls of the enclosure. The governing equations of the problem were solved numerically by the commercial code Fluent, based on the finite volume method and the Boussinesq approximation. The effects of Geometry Ratio GR and Rayleigh numbers on fluid flow and heat transfer performance are investigated. The Rayleigh number is varied from 103 to 106. Throughout the study the relevant results are presented in terms of isotherms, and streamlines. From the results, we found that the increase in the Geometry Ratio B leads to an increase of the heat transfer coefficient. The heat transfer rate in the annulus is translated in terms of the average Nusselt numbers along the enclosure's sides. Tecplot 7 program was used to plot the curves which cleared these relations and isotherms and streamlines which illustrate the behavior of air through the channel and its variation with other parameters. The results for the streamlines, isotherms, local and average Nusselt numbers average Nusselt numbers are compared with previous works and show good agreement.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 3; 17-29
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of strength properties of functionally graded structures with elliptical stress concentrators
Autorzy:
Stotsko, Z.A.
Kuzin, B.
Kuzin, M.O.
Mechanik, V.A.
Powiązania:
https://bibliotekanauki.pl/articles/2201119.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
elliptical stress concentrators
optimization of hardening modes
power load
computational mechanics
Opis:
Purpose: The purpose of this paper is to elaborate new calculation schemes for evaluating the strength parameters of railway rolling stock parts with non-local properties of surface layers in the presence of elliptical stress concentrators. Design/methodology/approach: Using the proposed approaches of developed mathematical modelling and open software for calculating FEniCS, it were established the most dangerous angles of stress concentrator orientation and the required thickness of the hardened zones of parts, which ensures their minimum softening during operation. Findings: It is shown that for an elliptical stress concentrator with any orientation angle, there is a certain key size of surface hardening thickness, the exceeding the value of which does not have influence on the operational strength of the parts, but rise the price of technological operations. Research limitations/implications: In this paper proposes a method for computation the impact of the orientation of the surface elliptical stress concentrators on the contact strength of parts under conditions of dominate friction power loads. Practical implications: The obtained results were used to set the modes of plasma hardening, which increase the contact strength of railway parts with elliptical stress concentrators. Originality/value: Using the approaches of contact mechanics, mathematical and computer modelling, methods of controlling the contact strength of the parts with the surface elliptical stress concentrators were proposed for the first time.
Źródło:
Archives of Materials Science and Engineering; 2022, 113, 1; 35--41
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical study of the effect of the presence of a geometric discontinuity of variable shape on the tensile strength of an epoxy polymer
Autorzy:
Saada, Khalissa
Amroune, Salah
Zaoui, Moussa
Houari, Amin
Madani, Kouider
Hachaichi, Amina
Powiązania:
https://bibliotekanauki.pl/articles/2204630.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
tensile test
hole-notched
elliptical-notched
XFEM
finite element method
Opis:
The presence of geometric discontinuity in a material reduces considerably its resistance to mechanical stresses, therefore reducing the service life of materials. The analysis of structural behaviour in the presence of geometric discontinuities is important to ensure the proper use, especially if it is regarding a material of weak mechanical properties such as a polymer. The objective of the present work is to analyse the effect of the notch presence of variable geometric shapes on the tensile strength of epoxy-type polymer specimens. A series of tensile tests were carried out on standardised specimens, taking into account the presence or absence of a notch. Each series of tests contains five specimens. Two notch shapes were considered: circular (hole) and elliptical. The experimental results in terms of stress–strain clearly show that the presence of notches reduces considerably the resistance of the material, where the maximum stress for the undamaged specimen was 41.22 MPa and the lowest stress for the elliptical-notched specimen was 11.21 MPa. A numerical analysis by the extended finite element method (XFEM) was undertaken on the same geometric models; in addition, the results in stress–strain form were validated with the experimental results. A remarkable improvement was obtained (generally an error within 0.06%) for strain, maximum stress, Young’s modulus and elongation values. An exponential decrease was noted in the stress, strain, and Young’s modulus in the presence of a notch in the material.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 2; 192--199
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on fatigue failure evolution in composite plate monitored by wave propagation method
Autorzy:
Stawiarski, Adam
Barski, Marek
Muc, Aleksander
Powiązania:
https://bibliotekanauki.pl/articles/2146563.pdf
Data publikacji:
2020
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
fatigue failure
wave propagation
composite plate
elliptical hole
uszkodzenie zmęczeniowe
propagacja fali
płyta kompozytowa
otwór eliptyczny
Opis:
In this study, the elastic wave propagation method is used to observe the initiation and evolution of the fatigue failure form in the multilayered composite plate with an elliptical hole. The experimental tests with the use of active, pitch-catch elastic wave measurement techniques are used during the fatigue test of the composite specimens. The fatigue tests were preceded by the numerical, finite element analysis of the elastic wave propagation phenomenon in a composite plate with an elliptical hole. The sequential measurement related to the number of cycles during the fatigue tests was assumed. The time of flight (ToF) and amplitude change was monitored by piezoelectric sensors localized in the area of predictable failure form evolution. The analysis of the dynamic response of the structure under fatigue loading conditions by a relatively small number of piezoelectric transduces allows us to build cost-effective Structural Health Monitoring (SHM) system for damage detection and monitoring of the failure form evolution.
Źródło:
Vibrations in Physical Systems; 2020, 31, 2; art. no. 2020227
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 43

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