• فهرس المقالات Perturbation

      • حرية الوصول المقاله

        1 - Fabrication of graded helical square tower-like Mn sculptured thin films and investigation of their electrical properties: comparison with perturbation theory
        Mahsa Fakharpour Hadi Savaloni
        10.1007/s40094-017-0242-3
        AbstractMn sculptured thin films were fabricated in form of graded helical square tower-like terraced sculptured Mn thin films (GHSTTS) using oblique angle deposition together with rotation of substrate about its surface normal with fixed rotation angle (90°) and a shad أکثر
        AbstractMn sculptured thin films were fabricated in form of graded helical square tower-like terraced sculptured Mn thin films (GHSTTS) using oblique angle deposition together with rotation of substrate about its surface normal with fixed rotation angle (90°) and a shadowing block which was fixed at the centre of the substrate holder. The anisotropy of the samples was examined by resistivity measurements at two orthogonal angles. Direct relationship is obtained between resistivity and the anisotropy of the produced samples which showed that both of these parameters increase with decreasing distance from the edge of the shadowing block. Simulation work using the perturbation theory produced results consistent with the experimental observations. تفاصيل المقالة
      • حرية الوصول المقاله

        2 - Effect of obliqueness and external magnetic field on the characteristics of dust acoustic solitary waves in dusty plasma with two-temperature nonthermal ions
        Akbar Sabetkar Davoud Dorranian
        10.1007/s40094-015-0172-x
        AbstractIn this paper, a theoretical investigation has been made of obliquely propagating dust acoustic solitary wave (DASW) structures in a cold magnetized dusty plasma consisting of a negatively charged dust fluid, electrons, and two different types of nonthermal ions أکثر
        AbstractIn this paper, a theoretical investigation has been made of obliquely propagating dust acoustic solitary wave (DASW) structures in a cold magnetized dusty plasma consisting of a negatively charged dust fluid, electrons, and two different types of nonthermal ions. The Zakharov–Kuznetsov (ZK) and modified Zakharov–Kuznetsov (MZK) equations, describing the small but finite amplitude DASWs, are derived using a reductive perturbation method. The combined effects of the external magnetic field, obliqueness (i.e. the propagation angle), and the presence of second component of nonthermal ions, which are found to significantly modify the basic features (viz. amplitude, width, polarity) of DASWs, are explicitly examined. The results show that the external magnetic field, the propagation angle, and the second component of nonthermal ions have strong effects on the properties of dust acoustic solitary structures. The solitary waves may become associated with either positive potential or negative potential in this model. As the angle between the direction of external magnetic field and the propagation direction of solitary wave increases, the amplitude of the solitary wave (for both positive potential and negative potential) increases. With changing this angle, the width of solitary wave shows a maximum. The magnitude of the external magnetic field has no direct effect on the solitary wave amplitude. However, with decreasing the strength of magnetic field, the width of DASW increases. تفاصيل المقالة
      • حرية الوصول المقاله

        3 - Linear and nonlinear analysis of dust acoustic waves in dissipative space dusty plasmas with trapped ions
        A. M. El-Hanbaly E. K. El-Shewy M. Sallah H. F. Darweesh
        10.1007/s40094-015-0175-7
        AbstractThe propagation of linear and nonlinear dust acoustic waves in a homogeneous unmagnetized, collisionless and dissipative dusty plasma consisted of extremely massive, micron-sized, negative dust grains has been investigated. The Boltzmann distribution is suggeste أکثر
        AbstractThe propagation of linear and nonlinear dust acoustic waves in a homogeneous unmagnetized, collisionless and dissipative dusty plasma consisted of extremely massive, micron-sized, negative dust grains has been investigated. The Boltzmann distribution is suggested for electrons whereas vortex-like distribution for ions. In the linear analysis, the dispersion relation is obtained, and the dependence of damping rate of the waves on the carrier wave number kdocumentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$k$$end{document}, the dust kinematic viscosity coefficient ηddocumentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$eta _{d}$$end{document} and the ratio of the ions to the electrons temperatures σidocumentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$sigma _{i}$$end{document} is discussed. In the nonlinear analysis, the modified Korteweg–de Vries–Burgers (mKdV–Burgers) equation is derived via the reductive perturbation method. Bifurcation analysis is discussed for non-dissipative system in the absence of Burgers term. In the case of dissipative system, the tangent hyperbolic method is used to solve mKdV–Burgers equation, and yield the shock wave solution. The obtained results may be helpful in better understanding of waves propagation in the astrophysical plasmas as well as in inertial confinement fusion laboratory plasmas. تفاصيل المقالة
      • حرية الوصول المقاله

        4 - Transverse perturbation on three-dimensional ion acoustic waves in electron–positron–ion plasma with high-energy tail electron and positron distribution
        M. Shahmansouri E. Astaraki
        10.1007/s40094-014-0148-2
        AbstractThe basic features of nonlinear ion acoustic (IA) waves are theoretically studied in a superthermal electron–positron–ion (e–p–i) plasma with weakly transverse perturbation. A three-dimensional Kadomtsev–Petviashvili (KP) equation governing evolution of weakly n أکثر
        AbstractThe basic features of nonlinear ion acoustic (IA) waves are theoretically studied in a superthermal electron–positron–ion (e–p–i) plasma with weakly transverse perturbation. A three-dimensional Kadomtsev–Petviashvili (KP) equation governing evolution of weakly nonlinear IA waves is derived by means of a reductive perturbation method. The energy integral equation is used to study the existence domain of the localized structures. It is found that deviation from thermodynamics equilibrium increases the existence domain of solitary solution and also makes the IA solitary structure more spiky. The ion concentration has an important effect on the existence domain of solitary solution, as for low ion density the primitive domain reduces significantly. تفاصيل المقالة
      • حرية الوصول المقاله

        5 - Theoretical analysis on nonlinear vibration of fluid flow in single-walled carbon nanotube
        P. Valipour S. E. Ghasemi Mohammad Reza Khosravani D. D. Ganji
        10.1007/s40094-016-0217-9
        AbstractIn this study, the concept of nonlocal continuum theory is used to characterize the nonlinear vibration of an embedded single-walled carbon nanotube. The Pasternak-type model is employed to simulate the interaction of the SWNTs. The parameterized perturbation me أکثر
        AbstractIn this study, the concept of nonlocal continuum theory is used to characterize the nonlinear vibration of an embedded single-walled carbon nanotube. The Pasternak-type model is employed to simulate the interaction of the SWNTs. The parameterized perturbation method is used to solve the corresponding nonlinear differential equation. The effects of the vibration amplitude, flow velocity, nonlocal parameter, and stiffness of the medium on the nonlinear frequency variation are presented. The result shows that by increasing the Winkler constant, the nonlinear frequency decreases, especially for low vibration amplitudes. In addition, it is resulted that influence of the nonlocal parameter is greater at higher flow velocities in comparison with lower flow velocities. تفاصيل المقالة
      • حرية الوصول المقاله

        6 - Multi-dimensional instability of dust-ion-acoustic solitary structure with opposite polarity ions and non-thermal electrons
        M. M. Haider O. Rahman
        10.1007/s40094-016-0229-5
        AbstractAn attempt has been made to study the multi-dimensional instability of dust-ion-acoustic (DIA) solitary waves (SWs) in magnetized multi-ion plasmas containing opposite polarity ions, opposite polarity dusts and non-thermal electrons. First of all, we have derive أکثر
        AbstractAn attempt has been made to study the multi-dimensional instability of dust-ion-acoustic (DIA) solitary waves (SWs) in magnetized multi-ion plasmas containing opposite polarity ions, opposite polarity dusts and non-thermal electrons. First of all, we have derived Zakharov-Kuznetsov (ZK) equation to study the DIA SWs in this case using reductive perturbation method as well as its solution. Small-k perturbation technique was employed to find out the instability criterion and growth rate of such a wave which can give a guideline in understanding the space and laboratory plasmas, situated in the D-region of the Earth’s ionosphere, mesosphere, and solar photosphere, as well as the microelectronics plasma processing reactors. تفاصيل المقالة
      • حرية الوصول المقاله

        7 - جریان ویسکوز دوبعدی درون شکافهای در حال انبساط یا در حال انقباض با دیواره های نفوذپذیر با استفاده از روش اغتشاش پارامتری (PPM)
        میراله حسینی
        در این مطالعه، مسئله جریان لایه‌ای، همدما، تراکم‌ناپذیر و ویسکوز در دامنه مستطیلی که به دو دیواره متخلخل متحرک مقید شده است و سیال می‌تواند از طریق انبساط یا انقباض‌های پی‌درپی از این دیواره‌ها وارد یا خارج شود، با استفاده از تکنیک تحلیلی مبتنی بر مجموعه «روش اختل أکثر
        در این مطالعه، مسئله جریان لایه‌ای، همدما، تراکم‌ناپذیر و ویسکوز در دامنه مستطیلی که به دو دیواره متخلخل متحرک مقید شده است و سیال می‌تواند از طریق انبساط یا انقباض‌های پی‌درپی از این دیواره‌ها وارد یا خارج شود، با استفاده از تکنیک تحلیلی مبتنی بر مجموعه «روش اختلال پارامتری شده (PPM)» حل می‌شود. ابتدا مفهوم این روش به اختصار بیان می‌گردد و سپس کاربردهای آن در این مسئله مورد مطالعه قرار می‌گیرند. آنگاه، نتایج با نتایج عددی مقایسه می‌شوند و اعتبار این روش‌ها سنجیده می‌شود. بعد از این اعتبارسنجی، اثر برخی پارامترهای کاربردپذیر فیزیکی تحلیل می‌شود تا کارایی PPM در این نوع مسائل نشان داده شود. نتایج گرافیکی برای بررسی تاثیر آهنگ اتساع دیواره بدون بعد ( ) و عدد رینولدز نفوذ (Re) بر سرعت، توزیع فشار نرمال و تنش برشی دیواره ارائه شده‌اند. مسئله حاضر که برای دیواره‌هایی با انبساط و انقباض کند و نفوذپذیری ضعیف طراحی شده است، یک مدل ساده برای انتقال سیالات زیستی از طریق رگ‌های در حال انقباض یا انبساط است. تفاصيل المقالة
      • حرية الوصول المقاله

        8 - حل دستگاه نامتناهی معادلات انتگرال غیرخطی بوسیله عملگر تراکمی - تعمیم‌‌یافته مر - کلر، اندازه نافشردگی و روش هموتوپی اختلالات بهبودیافته
        محسن ربانی رضا عرب
        در این مقاله برای اثبات وجود جواب دستگاه نامتناهی معادلات انتگرال غیرخطی، فضای جواب را فضای شامل همه دنباله‌های همگرا با حد متناهی که با نرم مناسب یک فضای باناخ است در نظر می‌گیریم. با ایجاد تعمیمی ازعملگرهای تراکمی مر - کلر بنام عملگرهای تراکمیF تعمیم‌یافته مر - کلر[1 أکثر
        در این مقاله برای اثبات وجود جواب دستگاه نامتناهی معادلات انتگرال غیرخطی، فضای جواب را فضای شامل همه دنباله‌های همگرا با حد متناهی که با نرم مناسب یک فضای باناخ است در نظر می‌گیریم. با ایجاد تعمیمی ازعملگرهای تراکمی مر - کلر بنام عملگرهای تراکمیF تعمیم‌یافته مر - کلر[1] و اندازه نافشردگی[2] به اثبات چند قضیه در خصوص وجود نقطه ثابت می‌پردازیم. با این کارسعی می‌کنیم بعضی از قضایایی که توسط نویسندگان دیگر [مانند 3, 19] در خصوص وجود جواب بوسیله قضایای نقطه ثابت ارایه شده است را گسترش دهیم. سپس برای اعتبار و کاربرد قضایای پیشنهادیمان، یک نمونه از دستگاه معادلات انتگرال غیرخطی نامتناهی را مورد نظر قرار داده و اثبات وجود جواب آن را به کمک قضایای فوق انجام می‌دهیم. در آخر برای توانمندی و جذابیت بیشتر این تحقیق، یک الگوریتم تکراری توسط روش هموتوپی اختلالات بهبودیافته و تجزیه ادومین[3] پدید آورده و از آن برای بدست آوردن جواب تقریبی دستگاه نامتناهی معادلات انتگرال غیرخطی فوق استفاده می‌کنیم.      تفاصيل المقالة
      • حرية الوصول المقاله

        9 - یک روش نیمه تحلیلی بهبود یافته‌ی جدید و سریع برای حل رده‌ای از معادلات انتگرال فوق منفرد نوع دوم
        رضا نوین محمد علی فریبرزی عراقی یعقوب محمودی
        هدف اصلی این تحقیق یافتن جواب تحلیلی رده ای از معادلات انتگرال فوق منفرد نوع دوم به نام پراندتل است که در مباحث فنی من جمله مکانیک پدید می آید. بدین منظور از یک روش بهبود یافته‌ی جدید و سریع بر اساس روش اختلال هموتوپی استفاده می شود. با ارائه‌ی مثال‌هایی نشان خواهیم داد أکثر
        هدف اصلی این تحقیق یافتن جواب تحلیلی رده ای از معادلات انتگرال فوق منفرد نوع دوم به نام پراندتل است که در مباحث فنی من جمله مکانیک پدید می آید. بدین منظور از یک روش بهبود یافته‌ی جدید و سریع بر اساس روش اختلال هموتوپی استفاده می شود. با ارائه‌ی مثال‌هایی نشان خواهیم داد که روش اختلال هموتوپی استاندارد در حالت کلی برای حل این رده از معادلات انتگرال همگرا نبوده و روش اختلال هموتوپی اصلاح شده نیز صرفاً زمانی همگرا است که جواب دقیق معادله از قبل مشخص باشد، اما روش پیشنهادی در این مقاله، بدون نیاز به دانستنن جواب دقیق مسئله، جواب دقیق این رده از معادلات انتگرال را در دومین تکرار از روش مشخص می‌کند. نتایج حاصل از مثالها مزایای روش بهبود یافته اختلال هموتوپی جدید را در مقایسه با روشهای استاندارد و اصلاح شده اختلال هموتوپی از جمله سادگی و سرعت بیشتر را نشان می دهد. تفاصيل المقالة
      • حرية الوصول المقاله

        10 - Detecting the location of the boundary layers in singular perturbation problems with general linear non-local boundary ‎conditions‎
        N. ‎Aliev S. Ashrafi A. R. Sarakhsi‎
        Singular perturbation problems have been studied by many mathematicians. Since the approximate solutions of these problems are as the sum of internal solution (boundary layer area) and external ones, the formation or non-formation of boundary layers should be specified. أکثر
        Singular perturbation problems have been studied by many mathematicians. Since the approximate solutions of these problems are as the sum of internal solution (boundary layer area) and external ones, the formation or non-formation of boundary layers should be specified. This paper, investigates this issue for a singular perturbation problem including a first order differential equation with general non-local boundary condition. It needs to say that it is simple for local boundary conditions and there is no difficulty. However, the formation of boundary layers for non-local case is not as stright forward as local case. To tackle this problem generalized solution of differential equation and some necessary conditions are ‎used.‎ تفاصيل المقالة
      • حرية الوصول المقاله

        11 - Some traveling wave solutions of soliton family
        S. Dhawan S. Kumar
        Solitons are ubiquitous and exist in almost every area from sky to bottom. For solitons to appear, the relevant equation of motion must be nonlinear. In the present study, we deal with the Korteweg-deVries (KdV), Modi ed Korteweg-de Vries (mKdV) and Regularised LongWave أکثر
        Solitons are ubiquitous and exist in almost every area from sky to bottom. For solitons to appear, the relevant equation of motion must be nonlinear. In the present study, we deal with the Korteweg-deVries (KdV), Modi ed Korteweg-de Vries (mKdV) and Regularised LongWave (RLW) equations using Homotopy Perturbation method (HPM). The algorithm makes use of the HPM to determine the initial expansion coecients using the initial value and boundary conditions. The physical structures of the nonlinear dispersive equation have been investigated for different parameters involved. It is shown how the nature of the waves look like in a simple way by considering the value of a certain single combination of constant parameters. The proposed scheme is standard, direct and computerized, which allow us to do complicated and tedious algebraic calculations. The ease of using this method to determine shock or solitary type of solutions, shows its power. تفاصيل المقالة
      • حرية الوصول المقاله

        12 - Modified homotopy perturbation method for solving non-linear oscillator's ‎equations
        A. R. Vahidi Z. Azimzadeh M. Shahrestani‎
        In this paper a new form of the homptopy perturbation method is used for solving oscillator differential equation, which yields the Maclaurin series of the exact solution. Nonlinear vibration problems and differential equation oscillations have crucial importance in all أکثر
        In this paper a new form of the homptopy perturbation method is used for solving oscillator differential equation, which yields the Maclaurin series of the exact solution. Nonlinear vibration problems and differential equation oscillations have crucial importance in all areas of science and engineering. These equations equip a significant mathematical model for dynamical systems. The accuracy of the Solution equation is very important because the analysis component of the system like vibration amplitude control, synchronization dynamics are dependent to the exact solution of oscillation ‎equation. تفاصيل المقالة
      • حرية الوصول المقاله

        13 - تشخیص ناپایداری ولتاژ در شین‌های بار با استفاده از اندیس‌های ZL /ZS و Indicator
        امیر الفتی
        در سال های گذشته روش هایی برای تشخیص به هنگام نواحی نزدیک به ناپایداری ولتاژ ارائه شده، که برخلاف روش های متداول محاسباتی ساده و سریع تر داشته و برمبنای اندازه گیری فازورهای محلی ولتاژ و جریان در باس ها یا خط های شبکه می باشند. اما برخی از آنها در شبکه های واقعی دارای أکثر
        در سال های گذشته روش هایی برای تشخیص به هنگام نواحی نزدیک به ناپایداری ولتاژ ارائه شده، که برخلاف روش های متداول محاسباتی ساده و سریع تر داشته و برمبنای اندازه گیری فازورهای محلی ولتاژ و جریان در باس ها یا خط های شبکه می باشند. اما برخی از آنها در شبکه های واقعی دارای کارکرد مناسبی نمی باشند، لذا در این مقاله به مقایسه کارکرد دو مورد از این اندیس ها پرداخته خواهد شد و درنهایت نشان داده خواهد شد کارکرد اندیس ZL / ZS نسبت به اندیس Indicator بهتر و قابل اعتمادتر می باشد. تفاصيل المقالة
      • حرية الوصول المقاله

        14 - Tangential Displacement and Shear Stress Distribution in Non-Uniform Rotating Disk under Angular Acceleration by Semi-Exact Methods
        S Jafari
        10.22034/jsm.2019.1879783.1504
        In this paper semi-exact methods are introduced for estimating the distribution of tangential displacement and shear stress in non-uniform rotating disks. At high variable angular velocities, the effect of shear stress on Von Mises stress is important and must be consid أکثر
        In this paper semi-exact methods are introduced for estimating the distribution of tangential displacement and shear stress in non-uniform rotating disks. At high variable angular velocities, the effect of shear stress on Von Mises stress is important and must be considered in calculations. Therefore, He’s homotopy perturbation method (HPM) and Adomian’s decomposition method (ADM) is implemented for solving equilibrium equation of rotating disk in tangential direction under variable mechanical loading. The results obtained by these methods are then verified by the exact solution and finite difference method. The comparison among HPM and ADM results shows that although the numerical results are the same approximately but HPM is much easier, straighter and efficient than ADM. Numerical calculations for different ranges of thickness parameters, boundary conditions and angular accelerations are carried out. It is shown that with considering disk profile variable, level of displacement and stress in tangential direction are not always reduced and type of changing the thickness along the radius of disk and boundary condition are an important factor in this case. Finally, the optimum disk profile is selected based on the tangential displacement-shear stress distribution. The presented algorithm is useful for the analysis of rotating disk with any arbitrary function form of thickness and density that it is impossible to find exact solutions. تفاصيل المقالة
      • حرية الوصول المقاله

        15 - Influence of Rigidity, Irregularity and Initial Stress on Shear Waves Propagation in Multilayered Media
        R.K Poonia N Basatiya V Kaliraman
        10.22034/jsm.2020.1896884.1572
        The propagation of shear waves in an anisotropic fluid saturated porous layer over a prestressed semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary has been studied. The re أکثر
        The propagation of shear waves in an anisotropic fluid saturated porous layer over a prestressed semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary has been studied. The rectangular irregularity has been taken in the half-space. The dispersion equation for shear waves is derived by using the perturbation technique followed by Fourier transformations. The dimensionless phase velocity is plotted against dimensionless wave number for the different size of ratios of depth of rectangular irregularity with the height of the layer and anisotropy parameters with the help of MATLAB graphical routines in presence and absence of initial stress. From the graphical results, it has been seen that the phase velocity is significantly influenced by the wave number, the depth of the irregularity, rigid boundary and initial stress. The acquired outcomes can be valuable for the investigation of geophysical prospecting and understanding the cause and evaluating of damage due to earthquakes. تفاصيل المقالة
      • حرية الوصول المقاله

        16 - Analysis of Coupled Nonlinear Radial-Axial Vibration of Single-Walled Carbon Nanotubes Using Numerical Methods
        A Fatahi-Vajari Z Azimzadeh
        10.22034/jsm.2019.1876588.1481
        This paper investigates the nonlinear coupled radial-axial vibration of single-walled carbon nanotubes (SWCNTs) based on numerical methods. Two coupled partial differential equations that govern the nonlinear coupled radial-axial vibration for such nanotube are derived أکثر
        This paper investigates the nonlinear coupled radial-axial vibration of single-walled carbon nanotubes (SWCNTs) based on numerical methods. Two coupled partial differential equations that govern the nonlinear coupled radial-axial vibration for such nanotube are derived using nonlocal doublet mechanics (DM) theory. To obtain the nonlinear natural frequencies in coupled radial-axial vibration mode, these equations are solved using Homotopy perturbation method (HPM). It is found that the coupled radial-axial vibrational frequencies are complicated due to coupling between two vibration modes. The influences of some commonly used boundary conditions, changes in vibration modes and variations of the nanotubes geometrical parameters on the nonlinear coupled radial-axial vibration characteristics of SWCNTs are discussed. It was shown that boundary conditions and maximum vibration velocity play significant roles in the nonlinear coupled radial-axial vibration response of SWCNTs. It was shown that unlike the linear one, the nonlinear natural frequencies are dependent to maximum vibration velocity. Increasing the maximum vibration velocity increases the natural frequency of vibration compared to the prediction of the linear model. However, with increase in tube length, the effect of the maximum vibration velocity on the natural frequencies decreases. It was also shown that the amount and variation of nonlinear natural frequencies are more apparent in higher vibration modes and two clamped boundary conditions. To show the accuracy and capability of this method, the results obtained herein are compared with the fourth order Runge-Kuta numerical results and also with the other available results and good agreement is observed. It is notable that the results generated herein are new and can be served as a benchmark for future works. تفاصيل المقالة
      • حرية الوصول المقاله

        17 - Analysis of Nonlinear Vibration of Piezoelectric Nanobeam Embedded in Multiple Layers Elastic Media in a Thermo-Magnetic Environment Using Iteration Perturbation Method
        M.G Sobamowo
        10.22034/jsm.2021.1911067.1648
        In this work, analysis of nonlinear vibration of piezoelectric nanobeam in a thermo-magnetic environment embedded in Winkler, Pasternak, quadratic and cubic nonlinear elastic media for simply supported and clamped boundary conditions is presented. With the consideration أکثر
        In this work, analysis of nonlinear vibration of piezoelectric nanobeam in a thermo-magnetic environment embedded in Winkler, Pasternak, quadratic and cubic nonlinear elastic media for simply supported and clamped boundary conditions is presented. With the considerations of Von- Karman geometric nonlinearity effect and with the aids of nonlocal elasticity theory as well as Euler–Bernoulli beam model, the equation of motion for the nanobeam is derived using Hamilton’s principle. The nonlinear dynamic model is solved using Galerkin-decomposition coupled with iteration perturbation method. From the parametric studies, it is shown that the frequency of the nanobeam increases at low temperatures but decreases at high temperatures. The nonlocal parameter decreases the frequencies of the piezoelectric nanobeam. An increase in the quadratic nonlinear elastic medium stiffness causes a decrease in the first mode of the nanobeam with clamped-clamped supports and an increase in all modes of the simply supported nanobeam at both low and high temperatures. When the magnetic force, cubic nonlinear elastic medium stiffness, and amplitude increase, there is an increase in all mode frequencies of the nanobeam. An increase in the temperature change at high temperature reduces the frequency ratio but at low or room temperature, an increase in temperature change, increases the frequency ratio of the structure nanotube. The significance of this study is evident in the design and applications of nanobeams in thermal and magnetic environments. تفاصيل المقالة
      • حرية الوصول المقاله

        18 - Magneto-Thermo-Elastic Behavior of Cylinder Reinforced with FG SWCNTs Under Transient Thermal Field
        A Ghorbanpour Arani M.R Mozdianfard V Sadooghi M Mohammadimehr R Kolahchi
        In this article, magneto-thermo-elastic stresses and perturbation of magnetic field vector are analyzed for a thick-walled cylinder made from polystyrene, reinforced with functionally graded (FG) single-walled carbon nanotubes (SWCNTs) in radial direction, while subject أکثر
        In this article, magneto-thermo-elastic stresses and perturbation of magnetic field vector are analyzed for a thick-walled cylinder made from polystyrene, reinforced with functionally graded (FG) single-walled carbon nanotubes (SWCNTs) in radial direction, while subjected to an axial and uniform magnetic field as well as a transient thermal field. Generalized plane strain state is considered in this study. The SWCNTs are assumed aligned, straight with infinite length. Two types of variations in the volume fraction of SWCNTs were considered in the structure of the FG cylinder along the radius from inner to outer surface, namely: functionally graded increasing (FG Inc) and functionally graded decreasing (FG Dec) which are then compared with uniformly distributed (UD) layouts. The constitutive equations of this type of reinforced polymeric cylinder are derived by Mori-Tanaka method. Following the introduction of a second order partial differential equation derived from the equations of motion and stress-strain relationships and solving by a semi-analytical method, distribution of stresses and perturbation of magnetic field vector are obtained. Results indicate that maximum radial and circumferential stresses occur in FG Inc and FG Dec layouts, respectively. Maximum perturbation of magnetic field vector is not affected by UD layout. تفاصيل المقالة
      • حرية الوصول المقاله

        19 - Free Vibration Analysis of a Nonlinear Beam Using Homotopy and Modified Lindstedt-Poincare Methods
        M.T Ahmadian M Mojahedi H Moeenfard
        In this paper, homotopy perturbation and modified Lindstedt-Poincare methods are employed for nonlinear free vibrational analysis of simply supported and double-clamped beams subjected to axial loads. Mid-plane stretching effect has also been accounted in the model. Gal أکثر
        In this paper, homotopy perturbation and modified Lindstedt-Poincare methods are employed for nonlinear free vibrational analysis of simply supported and double-clamped beams subjected to axial loads. Mid-plane stretching effect has also been accounted in the model. Galerkin's decomposition technique is implemented to convert the dimensionless equation of the motion to nonlinear ordinary differential equation. Homotopy and modified Lindstedt-Poincare (HPM) are applied to find analytic expressions for nonlinear natural frequencies of the beams. Effects of design parameters such as axial load and slenderness ratio are investigated. The analytic expressions are valid for a wide range of vibration amplitudes. Comparing the semi-analytic solutions with numerical results, presented in the literature, indicates good agreement. The results signify the fact that HPM is a powerful tool for analyzing dynamic and vibrational behavior of structures analytically. تفاصيل المقالة
      • حرية الوصول المقاله

        20 - Dynamic Response of an Axially Moving Viscoelastic Timoshenko Beam
        H Seddighi H.R Eipakchi
        In this paper, the dynamic response of an axially moving viscoelastic beam with simple supports is calculated analytically based on Timoshenko theory. The beam material property is separated to shear and bulk effects. It is assumed that the beam is incompressible in bul أکثر
        In this paper, the dynamic response of an axially moving viscoelastic beam with simple supports is calculated analytically based on Timoshenko theory. The beam material property is separated to shear and bulk effects. It is assumed that the beam is incompressible in bulk and viscoelastic in shear, which obeys the standard linear model with the material time derivative. The axial speed is characterized by a simple harmonic variation about a constant mean speed. The method of multiple scales with the solvability condition is applied to dimensionless form of governing equations in modal analysis and principal parametric resonance. By a parametric study, the effects of velocity, geometry and viscoelastic parameters are investigated on the response. تفاصيل المقالة
      • حرية الوصول المقاله

        21 - Effect of Non-ideal Boundary Conditions on Buckling of Rectangular Functionally Graded Plates
        J Mohammadi M Gheisary
        We have solved the governing equations for the buckling of rectangular functionally graded plates which one of its edges has small non-zero deflection and moment. For the case that the material properties obey a power law in the thickness direction, an analytical soluti أکثر
        We have solved the governing equations for the buckling of rectangular functionally graded plates which one of its edges has small non-zero deflection and moment. For the case that the material properties obey a power law in the thickness direction, an analytical solution is obtained using the perturbation series. The applied in-plane load is assumed to be perpendicular to the edge which has non-ideal boundary conditions. Making use of the Linshtead-Poincare perturbation technique, the critical buckling loads are obtained. The results were then verified with the known data in the literature. تفاصيل المقالة
      • حرية الوصول المقاله

        22 - Magneto-Thermo-Elastic Stresses and Perturbation of the Magnetic Field Vector in an EGM Rotating Disk
        A Ghorbanpour Arani M Azamia H Sepiani
        In this article, the magneto-thermo-elastic problem of exponentially graded material (EGM) hollow rotating disk placed in uniform magnetic and temperature fields is considered. Exact solutions for stresses and perturbations of the magnetic field vector in EGM hollow rot أکثر
        In this article, the magneto-thermo-elastic problem of exponentially graded material (EGM) hollow rotating disk placed in uniform magnetic and temperature fields is considered. Exact solutions for stresses and perturbations of the magnetic field vector in EGM hollow rotating disk are determined using the infinitesimal theory of magneto-thermo-elasticity under plane stress. The material properties, except Poisson’s ratio, are assumed to depend on variable of the radius and they are expressed as exponential functions of radius. The direct method is used to solve the heat conduction and Hyper-geometric functions are employed to solve Navier equation. The temperature, displacement, and stress fields and the perturbation of the magnetic field vector are determined and compared with those of the homogeneous case. Hence, the effect of in-homogeneity on the stresses and the perturbation of magnetic field vector distribution are demonstrated. The results of this study are applicable for designing optimum EGM hollow rotating disk. تفاصيل المقالة
      • حرية الوصول المقاله

        23 - Electro-magneto-thermo-mechanical Behaviors of a Radially Polarized FGPM Thick Hollow Sphere
        A Ghorbanpour Arani J Jafari Fesharaki M Mohammadimehr S Golabi
        In this study an analytical method is developed to obtain the response of electro-magneto-thermo-elastic stress and perturbation of a magnetic field vector for a thick-walled spherical functionally graded piezoelectric material (FGPM). The hollow sphere, which is placed أکثر
        In this study an analytical method is developed to obtain the response of electro-magneto-thermo-elastic stress and perturbation of a magnetic field vector for a thick-walled spherical functionally graded piezoelectric material (FGPM). The hollow sphere, which is placed in a uniform magnetic field, is subjected to a temperature gradient, inner and outer pressures and a constant electric potential difference between its inner and outer surfaces. The thermal, piezoelectric and mechanical properties except the Poisson’s ratio are assumed to vary with the power law functions through the thickness of the hollow sphere. By solving the heat transfer equation, in the first step, a symmetric distribution of temperature is obtained. Using the infinitesimal electro-magneto-thermo-elasticity theory, then, the Navier’s equation is solved and exact solutions for stresses, electric displacement, electric potential and perturbation of magnetic field vector in the FGPM hollow sphere are obtained. Moreover, the effects of magnetic field vector, electric potential and material in-homogeneity on the stresses and displacements distributions are investigated. The presented results indicate that the material in-homogeneity has a significant influence on the electro-magneto-thermo-mechanical behaviors of the FGPM hollow sphere and should therefore be considered in its optimum design. تفاصيل المقالة
      • حرية الوصول المقاله

        24 - Response Determination of a Beam with Moderately Large Deflection Under Transverse Dynamic Load Using First Order Shear Deformation Theory
        F Sohani H.R Eipakchi
        In the presented paper, the governing equations of a vibratory beam with moderately large deflection are derived using the first order shear deformation theory. The beam is homogenous, isotropic and it is subjected to the dynamic transverse and axial loads. The kinemati أکثر
        In the presented paper, the governing equations of a vibratory beam with moderately large deflection are derived using the first order shear deformation theory. The beam is homogenous, isotropic and it is subjected to the dynamic transverse and axial loads. The kinematic of the problem is according to the Von-Karman strain-displacement relations and the Hook's law is used as the constitutive equation. These equations which are a system of nonlinear partial differential equations with constant coefficients are derived by using the Hamilton’s principle. The eigenfunction expansion method and the perturbation technique are applied to obtain the response. The results are compared with the finite elements method. تفاصيل المقالة
      • حرية الوصول المقاله

        25 - Magneto-Thermo-Elastic Stresses and Perturbation of Magnetic Field Vector in a Thin Functionally Graded Rotating Disk
        A Ghorbanpour Arani S Amir
        In this paper, a semi-analytical solution for magneto-thermo-elastic problem in an axisymmetric functionally graded (FG) hollow rotating disk with constant thickness placed in uniform magnetic and thermal fields with heat convection from disk’s surfaces is present أکثر
        In this paper, a semi-analytical solution for magneto-thermo-elastic problem in an axisymmetric functionally graded (FG) hollow rotating disk with constant thickness placed in uniform magnetic and thermal fields with heat convection from disk’s surfaces is presented. Solution for stresses and perturbation of magnetic field vector in a thin FG rotating disk is determined using infinitesimal theory of magneto-thermo-elasticity under plane stress conditions. The material properties except Poisson’s ratio are modeled as power-law distribution of volume fraction. The non-dimensional distribution of temperature, displacement, stresses and perturbation of magnetic field vector throughout radius are determined. The effects of the material grading index and the magnetic field on the stress and displacement fields are investigated. The results of stresses and radial displacements for two different boundary conditions are compared with the case of a thin FG rotating disk with the same loading and boundary conditions but in the absence of magnetic field. It has been found that imposing a magnetic field significantly decreases tensile circumferential stresses. Therefore, the fatigue life of the disk will be significantly improved by applying the magnetic field. The results of this investigation can be used for optimum design of rotating disks. تفاصيل المقالة
      • حرية الوصول المقاله

        26 - Analytical and Numerical Modelling of the Axisymmetric Bending of Circular Sandwich Plates with the Nonlinear Elastic Core Material
        A Kudin S Choporov Yu Tamurov M.A.V Al Omari
        Herein paper compares the analytical model with the FEM based numerical model of the axisymmetric bending of circular sandwich plates. Also, the paper describes equations of the circular symmetrical sandwich plates bending with isotropic face sheets and the nonlinear el أکثر
        Herein paper compares the analytical model with the FEM based numerical model of the axisymmetric bending of circular sandwich plates. Also, the paper describes equations of the circular symmetrical sandwich plates bending with isotropic face sheets and the nonlinear elastic core material. The method of constructing an analytical solution of nonlinear differential equations has been described. The perturbation method for differential equations with small parameters is used to represent nonlinear differential equations as a sequence of linear equations. Linear differential equations are reduced to Bessel’s equation. It is compared results of analytical model with results of other researches using two problems: 1) the problem of axisymmetric transverse bending of a circular sandwich plate, 2) the problem of axisymmetric transverse bending of an annular sandwich plate. The effect of accounting nonlinear elastic core material on the strain state of the sandwich plate is described. تفاصيل المقالة
      • حرية الوصول المقاله

        27 - An Enhanced Viscoplastic Constitutive Model for Semi-Solid Materials to Analyze Shear Localization
        M.H Sheikh-Ansari M Aghaie-Khafri
        Semi-solid materials undergo strain localization and shear band formation as a result of granular nature of semi-solid deformation. In the present study, to analyze the shear localization, a unified viscoplastic constitutive model was developed for the homogeneous flow. أکثر
        Semi-solid materials undergo strain localization and shear band formation as a result of granular nature of semi-solid deformation. In the present study, to analyze the shear localization, a unified viscoplastic constitutive model was developed for the homogeneous flow. Then, a linearized analysis of the stability performed by examining the necessary condition for the perturbation growth. For this purpose, a shear layer model was considered to analyze the perturbation growth and subsequent instability. The perturbation analysis revealed that the failure mode in semi-solid materials is diffused with long wave length regime, rather than to be localized and exhibiting short wave length regime. Moreover, decreasing the solid skeleton has a retarding effect on the perturbation growth and localization at low and modest strain rates. The performed analysis showed that the localization analysis results in a new interpretation for the micro-mechanisms of the semi-solid deformation. The constitutive model was fairly well correlated with the experimental results. تفاصيل المقالة
      • حرية الوصول المقاله

        28 - Spectral Method for Solving Fuzzy Volterra Integral Equations of Second kind
        Laleh Hooshangian
        This paper, about the solution of fuzzy Volterra integral equation of fuzzy Volterra integralequation of second kind (F-VIE2) using spectral method is discussed. The parametric form offuzzy driving term is applied for F-VIE2. Then three cases for (F-VIE2) are searched t أکثر
        This paper, about the solution of fuzzy Volterra integral equation of fuzzy Volterra integralequation of second kind (F-VIE2) using spectral method is discussed. The parametric form offuzzy driving term is applied for F-VIE2. Then three cases for (F-VIE2) are searched to solvethem. These classifications are considered based on the sign of interval. The Gauss-Legendrepoints and Legendre weights for arithmetics in spectral method are used to solve (F-VIE2).Finally, two examples are got to illustrate more. تفاصيل المقالة
      • حرية الوصول المقاله

        29 - Some notes on convergence of homotopy based methods for functional equations
        A Azizi J Saeidian E Babolian
        Although homotopy-based methods, namely homotopy analysis method andhomotopy perturbation method, have largely been used to solve functionalequations, there are still serious questions on the convergence issue of thesemethods. Some authors have tried to prove convergenc أکثر
        Although homotopy-based methods, namely homotopy analysis method andhomotopy perturbation method, have largely been used to solve functionalequations, there are still serious questions on the convergence issue of thesemethods. Some authors have tried to prove convergence of these methods, butthe researchers in this article indicate that some of those discussions are faulty.Here, after criticizing previous works, a sucient condition for convergence ofhomotopy methods is presented. Finally, examples are given to show that evenif the homotopy method leads to a convergent series, it may not converge tothe exact solution of the equation under consideration. تفاصيل المقالة
      • حرية الوصول المقاله

        30 - Homotopy Perturbation Method and Aboodh Transform for Solving Nonlinear Partial Differential Equations
        Khalid Aboodh
        Here, a new method called Aboodh transform homotopy perturbation method(ATHPM) is used to solve nonlinear partial di erential equations, we presenta reliable combination of homotopy perturbation method and Aboodh transformto investigate some nonlinear partial di erentia أکثر
        Here, a new method called Aboodh transform homotopy perturbation method(ATHPM) is used to solve nonlinear partial di erential equations, we presenta reliable combination of homotopy perturbation method and Aboodh transformto investigate some nonlinear partial di erential equations. The nonlinearterms can be handled by the use of homotopy perturbation method. The resultsshow the eciency of this method. Aboodh transform was introducedby Khalid Aboodh to facilitate the process of solving ordinary and partialdifferential equations in the time domain. تفاصيل المقالة
      • حرية الوصول المقاله

        31 - Some notes on convergence of homotopy based methods for functional equations
        A. Azizi J. Saiedian E. Babolian
        Although homotopy-based methods, namely homotopy analysis method andhomotopy perturbation method, have largely been used to solve functionalequations, there are still serious questions on the convergence issue of thesemethods. Some authors have tried to prove convergenc أکثر
        Although homotopy-based methods, namely homotopy analysis method andhomotopy perturbation method, have largely been used to solve functionalequations, there are still serious questions on the convergence issue of thesemethods. Some authors have tried to prove convergence of these methods, butthe researchers in this article indicate that some of those discussions are faulty.Here, after criticizing previous works, a sucient condition for convergence ofhomotopy methods is presented. Finally, examples are given to show that evenif the homotopy method leads to a convergent series, it may not converge tothe exact solution of the equation under consideration. تفاصيل المقالة
      • حرية الوصول المقاله

        32 - New Integral Transform for Solving Nonlinear Partial Di erential Equations of fractional order
        A. Neamaty B. Agheli R. Darzi
        In this work, we have applied Elzaki transform and He's homotopy perturbation method to solvepartial di erential equation (PDEs) with time-fractional derivative. With help He's homotopy per-turbation, we can handle the nonlinear terms. Further, we have applied this sugg أکثر
        In this work, we have applied Elzaki transform and He's homotopy perturbation method to solvepartial di erential equation (PDEs) with time-fractional derivative. With help He's homotopy per-turbation, we can handle the nonlinear terms. Further, we have applied this suggested He's homotopyperturbation method in order to reformulate initial value problem. Some illustrative examples aregiven in order to show the ability and simplicity of the approach. All numerical calculations in thismanuscript were performed on a PC applying some programs written in Maple. تفاصيل المقالة
      • حرية الوصول المقاله

        33 - Numerical solution of seven-order Sawada-Kotara equations by homotopy perturbation method
        M. Ghasemi A. Azizi M. Fardi
        In this paper, an application of homotopy perturbation method is appliedto nding the solutions of the seven-order Sawada-Kotera (sSK) and a Lax'sseven-order KdV (LsKdV) equations. Then obtain the exact solitary-wave so-lutions and numerical solutions of the sSK and LsK أکثر
        In this paper, an application of homotopy perturbation method is appliedto nding the solutions of the seven-order Sawada-Kotera (sSK) and a Lax'sseven-order KdV (LsKdV) equations. Then obtain the exact solitary-wave so-lutions and numerical solutions of the sSK and LsKdV equations for the initialconditions. The numerical solutions are compared with the known analyticalsolutions. Their remarkable accuracy are nally demonstrated for the bothseven-order equations. تفاصيل المقالة
      • حرية الوصول المقاله

        34 - Numerical Solution of a New Type Fuzzy Nonlinear Volterra Integral Equations
        Laleh Hooshangian
        Fuzzy integral equations play a fundamental role in the many fields of engineering and applied mathematics.The paper presented, a new type of fuzzy Volterra integral equations of the second kind with nonlinear fuzzykernels. Numerical solutions of a new type of nonlinear أکثر
        Fuzzy integral equations play a fundamental role in the many fields of engineering and applied mathematics.The paper presented, a new type of fuzzy Volterra integral equations of the second kind with nonlinear fuzzykernels. Numerical solutions of a new type of nonlinear fuzzy Volterra integral equations with nonlinear fuzzy kernels through Variational Homotopy perturbation (VHP) method based on the parametric form of a fuzzy number, is investigated. To find the approximate solution and to get an approximation for fuzzy solution of the new type of nonlinear fuzzy Volterra integral equations the VHPM is applied, and it is shown that VHPM is an effective and reliable approach to solve these equations. Finally, a few numerical examples are given and results unfold that VHPM is very close to exact solutions. The obtained approximate solutions are contrasted with the exact solution, and absolute error between obtaining numerical results and an exact solution are found. One of the examples shows a comparison between VHPM and HPM. تفاصيل المقالة
      • حرية الوصول المقاله

        35 - A Novel Robust Adaptive Trajectory Tracking in Robot Manipulators
        Shaghayegh Gorji Mohammad Javad Yazdanpanah
        In this paper, a novel adaptive sliding mode control for rigid robot manipulators is proposed. In the proposed system, since there may exist explicit unknown parameters and perturbations, a Lyapunov based approach is presented to increase system robustness, even in pres أکثر
        In this paper, a novel adaptive sliding mode control for rigid robot manipulators is proposed. In the proposed system, since there may exist explicit unknown parameters and perturbations, a Lyapunov based approach is presented to increase system robustness, even in presence of arbitrarily large (but not infinite) discontinuous perturbations. To control and track the robot, a continuous controller is designed with two phases of adaptation. The first phase is related to the robot parameters and the other one is accounted for perturbation estimating. We investigated the stability in the sense of Lyapunov with derive adaptive laws and uniform ultimate boundedness in the applied worst condition. The simulation results for two degrees of freedom rigid robot manipulator effectively demonstrate capability of the mentioned approach. Moreover, the results show that the domain of attraction is so vast and a global uniform ultimate boundedness could be expected. تفاصيل المقالة
      • حرية الوصول المقاله

        36 - Adaptive Sliding Mode Tracking Control of Mobile Robot in Dynamic Environment Using Artificial Potential Fields
        Abolfath Nikranjbar Masoud Haidari Ali Asghar Atai
        Solution to the safe and collision-free trajectory of the wheeled mobile robot in cluttered environments containing the static and/or dynamic obstacle has become a very popular and challenging research topic in the last decade. Notwithstanding of the amount of publicati أکثر
        Solution to the safe and collision-free trajectory of the wheeled mobile robot in cluttered environments containing the static and/or dynamic obstacle has become a very popular and challenging research topic in the last decade. Notwithstanding of the amount of publications dealing with the different aspects of this field, the ongoing efforts to address the more effective and creative methods is continued. In this article, the effectiveness of the real-time harmonic potential field theory based on the panel method to generate the reference path and the orientation of the trajectory tracking control of the three-wheel nonholonomic robot in the presence of variable-size dynamic obstacle is investigated. The hybrid control strategy based on a backstepping kinematic and regressor-based adaptive integral sliding mode dynamic control in the presence of disturbance in the torque level and parameter uncertainties is employed. In order to illustrate the performance of the proposed adaptive algorithm, a hybrid conventional integral sliding mode dynamic control has been established. The employed control methods ensure the stability of the controlled system according to Lyapunov’s stability law. The results of simulation program show the remarkable performance of the both methods as the robust dynamic control of the mobile robot in tracking the reference path in unstructured environment containing variable-size dynamic obstacle with outstanding disturbance suppression characteristic. تفاصيل المقالة
      • حرية الوصول المقاله

        37 - Switching H2/H∞ Controller Design for Linear Singular Perturbation Systems
        Ahmad Fakharian
        This paper undertakes the synthesis of a logic-based switching H2/H∞ state-feedback controller for continuous-time LTI singular perturbation systems. Our solution achieves a minimum bound on the H2 performance level, while also satisfying the H∞ performance أکثر
        This paper undertakes the synthesis of a logic-based switching H2/H∞ state-feedback controller for continuous-time LTI singular perturbation systems. Our solution achieves a minimum bound on the H2 performance level, while also satisfying the H∞ performance requirements. The proposed hybrid control scheme is based on a fuzzy supervisor managing the combination of two controllers. A convex LMI-Based formulation of two fast and slow subsystem controllers leads to a structure which ensures a good performance in both transient and steady-state phases. The stability analysis leverages on the Lyapunov technique, inspired from the switching system theory, to prove that a system with the proposed controller remains globally stable in the face of changes in configuration (controller). تفاصيل المقالة
      • حرية الوصول المقاله

        38 - Shifted Chebyshev Approach for the Solution of Delay Fredholm and Volterra Integro-Differential Equations via Perturbed Galerkin Method
        Kazeem Issa Jafar Biazar Babatunde Yisa
        The main idea proposed in this paper is the perturbed shifted Chebyshev Galerkin method for the solutions of delay Fredholm and Volterra integrodifferential equations. The application of the proposed method is also extended to the solutions of integro-differential differen أکثر
        The main idea proposed in this paper is the perturbed shifted Chebyshev Galerkin method for the solutions of delay Fredholm and Volterra integrodifferential equations. The application of the proposed method is also extended to the solutions of integro-differential difference equations. The method is validated using some selected problems from the literature. In all the problems that are considered, the new proposed approach performs better than many other methods. تفاصيل المقالة
      • حرية الوصول المقاله

        39 - Numerical solution of integro-differential equations via pertubed-Gegenbauer, Jacobi polynomials and Galerkin method
        Kazeem Issa Kazeem Aliu Kazeem Arokoola Kazeem Micah
        In this paper, we proposed perturbed Galerkin method for solving integro-differential equations via shifted Gegenbauer and shifted Jacobi polynomials as approximating polynomials. We use Galerkin method to transform the perturbed integro-differential equation to system أکثر
        In this paper, we proposed perturbed Galerkin method for solving integro-differential equations via shifted Gegenbauer and shifted Jacobi polynomials as approximating polynomials. We use Galerkin method to transform the perturbed integro-differential equation to system of linear algebraic equations and obtained N + 1 linear equations with N +m+2 unknowns. Moreover, with m+1 boundary conditions we obtained N +m+2 algebraic equations which was then solved to obtain the approximate solutions at various values of α and β depending on the orthogonal polynomials, that’s shifted Gegenbauer or shifted Jacobi polynomials. The proposed method was implemented on some selected problems in the literature to validate the effectiveness and the accuracy of the proposed method. تفاصيل المقالة
      • حرية الوصول المقاله

        40 - Solving Nonlinear Klein-Gordon Equation with a Quadratic Nonlinear term using Homotopy Analysis Method
        H. جعفری م. سعیدی م. عرب فیروزجایی
        In this paper, nonlinear Klein-Gordon equation with quadratic term is solved by means of an analytic technique, namely the Homotopy analysis method (HAM).Comparisons are made between the Adomian decomposition method (ADM), the exact solution and homotopy analysis method أکثر
        In this paper, nonlinear Klein-Gordon equation with quadratic term is solved by means of an analytic technique, namely the Homotopy analysis method (HAM).Comparisons are made between the Adomian decomposition method (ADM), the exact solution and homotopy analysis method. The results reveal that the proposed method is very effective and simple. تفاصيل المقالة
      • حرية الوصول المقاله

        41 - Analytic-Approximate Solution For An Integro- Differential Equation Arising In Oscillating Magnetic Fields Using Homotopy Analysis Method
        H. صابری نیک S. عفتی ر. بوژآبادی
        In this paper, we give an analytical approximate solution for an integro- differential equation which describes the charged particle motion for certain configurations of oscillating magnetic fields is considered. The homotopy analysis method (HAM) is used for solving th أکثر
        In this paper, we give an analytical approximate solution for an integro- differential equation which describes the charged particle motion for certain configurations of oscillating magnetic fields is considered. The homotopy analysis method (HAM) is used for solving this equation. Several examples are given to reconfirm the efficiency of these algorithms. The results of applying this procedure to the integro-differential equation with time-periodic coefficients show the high accuracy, simplicity and efficiency of this method. تفاصيل المقالة
      • حرية الوصول المقاله

        42 - A new robust counterpart model for uncertain linear programming problems
        Hamid Amiri Rasoul Shafaei
        10.30495/jiei.2023.1958190.1227
        Many practical decision-making problems involve a significant level of data uncertainty. In such a case, modeling the uncertainty involved is critical to making informed decisions. The set-based robust optimization approach is one of the most efficient techniques for fi أکثر
        Many practical decision-making problems involve a significant level of data uncertainty. In such a case, modeling the uncertainty involved is critical to making informed decisions. The set-based robust optimization approach is one of the most efficient techniques for finding optimal decisions in problems involving uncertain data. The main concern with this technique is over-conservatism. This drawback has been widely investigated, and several robust formulations have been developed in the literature to deal with it. However, research is still ongoing to obtain effective formulations to handle uncertainty. In this study, we derive a robust counterpart formulation for an uncertain linear programming problem under a new uncertainty set that is defined based on a pairwise comparison of perturbation variables. The performance of the proposed robust formulation is evaluated using numerical studies and in terms of different performance metrics. For this purpose, robust counterpart models corresponding to the production-mix sample problems are solved at different protection levels. Then, for each solution obtained, violation probability is calculated using a Monte-Carlo simulation approach. The results revealed that the proposed method outperforms the existing ones. تفاصيل المقالة
      • حرية الوصول المقاله

        43 - بررسی صحت تقریب اغتشاش برای پراکندگی صوت در دریا در اثر طیف پیرسون – مسکویچ
        افشین محسنی آراسته کامران لاری محمد سمنانی نژاد
        جذب و پراکندگی صوت یکی از مباحث مهم مطالعه فیزیکی دریاها و اقیانوس ها است. در این مقاله به بررسی پراکندگی صوت در اثر طیف پیرسون– مسکویچ پرداخته شده است. در این مطالعه تقریبات اغتشاش برای پراکندگی از سطوح دریا در حضور این طیف بررسی شده و با نتایج واقعی نمونه به دست أکثر
        جذب و پراکندگی صوت یکی از مباحث مهم مطالعه فیزیکی دریاها و اقیانوس ها است. در این مقاله به بررسی پراکندگی صوت در اثر طیف پیرسون– مسکویچ پرداخته شده است. در این مطالعه تقریبات اغتشاش برای پراکندگی از سطوح دریا در حضور این طیف بررسی شده و با نتایج واقعی نمونه به دست آمده توسط معادله انتگرال مقایسه شده است. همه نتایج در این تحقیق برای فرکانس صوت HZ200 و برای زاویه تابش º 20- º 10 درجه می باشد. که برای مثال های بررسی شده تئوری مرتبه اول اغتشاش برای سطوح پراکندگی به عقب dB 3-1 کمتر را نشان می دهد و برای زوایای تابش 20 درجه وقتی ارتفاع سطح زیاد می شود تئوری اغتشاش با نتایج معادله انتگرال منطبق است. تفاصيل المقالة
      • حرية الوصول المقاله

        44 - Nonlinear Vibration Analysis of a cantilever beam with nonlinear geometry
        محمود مهدی ماشینچی ح. جوانیان جویباری د. گنجی
        Analyzing the nonlinear vibration of beams is one of the important issues in structural engineering. According to this, an impressive analytical method which is called Modified Iteration Perturbation Method (MIPM) is used to obtain the behavior and frequency of a cantil أکثر
        Analyzing the nonlinear vibration of beams is one of the important issues in structural engineering. According to this, an impressive analytical method which is called Modified Iteration Perturbation Method (MIPM) is used to obtain the behavior and frequency of a cantilever beam with geometric nonlinear. This new method is combined by the Mickens and Iteration methods. Moreover, this method don’t require small parameter in the equation which is difficult to be found for nonlinear oscillation. The accuracy of the solution that is obtained by using of MIPM has been shown graphically and compared with exact solution. Comparison shows that good adaptation is obtained and MIPM is a powerful method for solving the vibrational behavior of structures analytically. تفاصيل المقالة
      • حرية الوصول المقاله

        45 - New Maximum Power Point Tracking Technique Based on P&O Method
        Mostafa Alizadeh Soltani Shahram Javadi Seyed Zeinolabedin Moussavi
        In the most described maximum power point tracking (MPPT) methods in the literatures, the optimal operation point of the photovoltaic (PV) systems is estimated by linear approximations. However, these approximations can lead to less optimal operating conditions and sign أکثر
        In the most described maximum power point tracking (MPPT) methods in the literatures, the optimal operation point of the photovoltaic (PV) systems is estimated by linear approximations. However, these approximations can lead to less optimal operating conditions and significantly reduce the performances of the PV systems. This paper proposes a new approach to determine the maximum power point (MPP) in order to increasing the system efficiently as much as possible. The proposed algorithm is a combination of two loops, set point calculation and fine tuning loops. In first stage, the maximum power is approximated based on the nonlinear modeling of the PV panels by using the set point loop. In second stage, the exact amount of the maximum power will be tracked by the fine tuning loop, which is based on the Perturbation and Observation (P&O) method. The proposed method is simulated in MATLAB/SIMULINK software environment. The simulation results demonstrate that the approach clearly improves the tracking efficiency of the maximum power available at the output of the PV panels. The new method reduces the oscillations around the MPP as well as increases the average efficiency of the obtained MPPT. The new MPPT method will deliver more power to any generic load or energy storage media تفاصيل المقالة
      • حرية الوصول المقاله

        46 - A new Approximation to the solution of the linear matrix equation AXB = C
        A. Sadeghi
        It is well-known that the matrix equations play a significant role in several applications in science and engineering. There are various approaches either direct methods or iterative methods to evaluate the solution of these equations. In this research article, the homo أکثر
        It is well-known that the matrix equations play a significant role in several applications in science and engineering. There are various approaches either direct methods or iterative methods to evaluate the solution of these equations. In this research article, the homotopy perturbation method (HPM) will employ to deduce the approximated solution of the linear matrix equation in the form AXB=C. Furthermore, the conditions will be explored to check the convergence of the homotopy series. Numerical examples are also adapted to illustrate the properties of the modified method. تفاصيل المقالة
      • حرية الوصول المقاله

        47 - A new approach to solve fuzzy system of linear equations by Homotopy perturbation method
        M. Paripour J. Saeidian A. Sadeghi
        In this paper, we present an efficient numerical algorithm for solving fuzzy systemsof linear equations based on homotopy perturbation method. The method is discussed indetail and illustrated by solving some numerical examples.
        In this paper, we present an efficient numerical algorithm for solving fuzzy systemsof linear equations based on homotopy perturbation method. The method is discussed indetail and illustrated by solving some numerical examples. تفاصيل المقالة
      • حرية الوصول المقاله

        48 - Analytical Solution of Steady State Substrate Concentration of an Immobilized Enzyme Kinetics by Laplace Transform Homotopy Perturbation Method
        Devipriya Ganeshan
        The nonlinear dynamical system modeling the immobilized enzyme kinetics with Michaelis-Menten mechanism for an irreversible reaction without external mass transfer resistance is considered. Laplace transform homotopy perturbation method is used to obtain the approximate أکثر
        The nonlinear dynamical system modeling the immobilized enzyme kinetics with Michaelis-Menten mechanism for an irreversible reaction without external mass transfer resistance is considered. Laplace transform homotopy perturbation method is used to obtain the approximate solution of the governing nonlinear differential equation, which consists in determining the series solution convergent to the exact solution or enabling to built the approximate solution of the problem. Numerical solutions are obtained and the results are discussed graphically. The method allows to determine the solution in form of the continuous function, which is significant for the analysis of the steady state dimensionless substrate concentration with dimensionless distance on the different support materials. تفاصيل المقالة
      • حرية الوصول المقاله

        49 - Solving Fuzzy Impulsive Fractional Differential Equations by Homotopy Perturbation Method
        Nematallah Najafi
        In this paper, we study semi-analytical methods entitled Homotopy pertourbation method (HPM) to solve fuzzy impulsive fractional differential equations based on the concept of generalized Hukuhara differentiability. At the end first of Homotopy pertourbation method is d أکثر
        In this paper, we study semi-analytical methods entitled Homotopy pertourbation method (HPM) to solve fuzzy impulsive fractional differential equations based on the concept of generalized Hukuhara differentiability. At the end first of Homotopy pertourbation method is defined and its properties are considered completely. Then econvergence theorem for the solution are proved and we will show that the approximate solution convergent to the exact solution. Some examples indicate that this method can be easily applied to many linear and nonlinear problems. تفاصيل المقالة
      • حرية الوصول المقاله

        50 - Analytical Solution of the Effect of Awareness Program by Media on the Spread of an Infectious Disease by Homotopy Perturbation Method
        Devipriya Ganeshan
        10.30495/ijm2c.2022.1937350.1228
        In this paper, the nonlinear dynamical system modeling the effect of awareness program by media on spread of infectious disease is considered. The model is mathematically formulated by the deterministic compartmental model consisting of susceptible population, infected أکثر
        In this paper, the nonlinear dynamical system modeling the effect of awareness program by media on spread of infectious disease is considered. The model is mathematically formulated by the deterministic compartmental model consisting of susceptible population, infected population, aware population and cumulative density of awareness spread by the media. Homotopy perturbation method is used to obtain the approximate solution of the governing nonlinear differential equation, which consists in determining the series solution convergent to the exact solution or enabling to built the approximate solution of the problem. Numerical solutions are obtained and the results are discussed graphically using Maple. The method allows to determine the solution in form of the continuous function, and shows the significance of awareness program driven by media in spread of an infectious disease, but due to immigration, the disease may remain endemic . The simulation analysis of the model with different parameter values confirms the analytical results. تفاصيل المقالة
      • حرية الوصول المقاله

        51 - THE APPLICATION OF THE VARIATIONAL HOMOTOPY PERTURBATION METHOD ON THE GENERALIZED FISHER'S EQUATION
        M. Matinfar M. Mahdavi
        In this paper, we consider the variational homotopy perturbation method (VHPM) to obtain an approximate series solution for the generalized Fisher’s equation which converges to the exact solution in the region of convergence. Comparisons are made among the variati أکثر
        In this paper, we consider the variational homotopy perturbation method (VHPM) to obtain an approximate series solution for the generalized Fisher’s equation which converges to the exact solution in the region of convergence. Comparisons are made among the variational iteration method (VIM), the exact solutions and the proposed method. The results reveal that the proposed method is very effective and simple and can be applied for other nonlinear problems in mathematical. تفاصيل المقالة
      • حرية الوصول المقاله

        52 - THE ELZAKI HOMOTOPY PERTURBATION METHOD FOR PARTIAL DIFFERENTIAL EQUATIONS
        M. Matinfar M. Ghasemi
        In this paper, Elzaki Homotopy Perturbation Method is employed for solving linear and nonlinear differential equations with a variable coffecient. This method is a combination of Elzaki transform and Homotopy Perturbation Method. The aim of using Elzaki transform is to أکثر
        In this paper, Elzaki Homotopy Perturbation Method is employed for solving linear and nonlinear differential equations with a variable coffecient. This method is a combination of Elzaki transform and Homotopy Perturbation Method. The aim of using Elzaki transform is to overcome the deficiencies that mainly caused by unsatised conditions in some semi-analytical methods such as Homotopy Perturbation Method, Variational Iteration Method and Adomian Decomposition Method. The approximate solutions obtained by means of Elzaki Homotopy Perturbation Method were compared in a wide range of problem's domain with those results obtained by Homotopy Perturbation Method. The comparison shows a precise agreement between the exact solutions and the obtained results by this new method as an applicable one, which needs less computations and is much easier and more convenient than others. So, it can be widely used in engineering and other branches of science. تفاصيل المقالة
      • حرية الوصول المقاله

        53 - STUDY OF OIL SPILL ON THE SEA SURFACE IN THE PRESENCE OF THERMAL AND CONCENTRATION BUOYANCY EFFECTS
        Nirmala P Ratchagar S. V. Hemalatha
        Pollution occurs when the concentration of various chemical or biological constituents exceed a level implying negative impact on amenities, the eco-system, resources and human health. Oil spills are the serious environmental hazards which often exhibit long-term impact أکثر
        Pollution occurs when the concentration of various chemical or biological constituents exceed a level implying negative impact on amenities, the eco-system, resources and human health. Oil spills are the serious environmental hazards which often exhibit long-term impacts. The main objective of response to an oil spill is to reduce its impact on nature and human health. This paper allows us to get a comprehensive idea of the oil spill impact in the presence of thermal and concentration buoyancy effects. The governing equations and their associated boundary conditions are first cast into dimensionless form and the resulting equations are then solved analytically using perturbation technique. The effect of various physical parameters such as Grashof number, Prandtl number, Schmidt number and chemical reaction parameter on the velocity, temperature and concentration profile as well as surface skin friction, heat and mass transfer coefficients are discussed in detail with the help of graphs. تفاصيل المقالة
      • حرية الوصول المقاله

        54 - VARIATIONAL HOMOTOPY PERTURBATION METHOD FOR SOLVING THE NONLINEAR GAS DYNAMICS EQUATION
        M. Matinfar Z. Raeisi
        A. Noor et al. [7] analyze a technique by combining the variational iteration method and the homotopy perturbation method which is called the variational homotopy perturbation method (VHPM) for solving higher dimensional initial boundary value problems. In this paper, w أکثر
        A. Noor et al. [7] analyze a technique by combining the variational iteration method and the homotopy perturbation method which is called the variational homotopy perturbation method (VHPM) for solving higher dimensional initial boundary value problems. In this paper, we consider the VHPM to obtain exact solution to Gas Dynamics equation. تفاصيل المقالة
      • حرية الوصول المقاله

        55 - A NEW MODIFIED HOMOTOPY PERTURBATION METHOD FOR SOLVING LINEAR SECOND-ORDER FREDHOLM INTEGRO-DIFFERENTIAL EQUATIONS
        M. Sotoodeh M. A Fariborzi Araghi
        In this paper, we tried to accelerate the rate of convergence in solving second-order Fredholm type Integro-differential equations using a new method which is based on Improved homotopy perturbation method (IHPM) and applying accelerating parameters. This method is very أکثر
        In this paper, we tried to accelerate the rate of convergence in solving second-order Fredholm type Integro-differential equations using a new method which is based on Improved homotopy perturbation method (IHPM) and applying accelerating parameters. This method is very simple and the result is obtained very fast. تفاصيل المقالة
      • حرية الوصول المقاله

        56 - NONLINEAR CONTROL OF HEAT TRANSFER DYNAMIC USING HOMOTOPY PERTURBATION METHOD (HPM)
        Jamal Ghasemi
        Nonlinear problems are more challenging and almost complex to be solved. A recently developed Homotopy Perturbation Method (HPM) is introduced. This method is used to represent the system as a less complicated (almost linear) model. To verify the effectiveness, HPM base أکثر
        Nonlinear problems are more challenging and almost complex to be solved. A recently developed Homotopy Perturbation Method (HPM) is introduced. This method is used to represent the system as a less complicated (almost linear) model. To verify the effectiveness, HPM based model is compared with the nonlinear dynamic in both open and closed loop PI controlled. The error indices are approximation of possible uncertainties which may be occurred. The simulation results reveal the ability of the proposed method. تفاصيل المقالة
      • حرية الوصول المقاله

        57 - Numerical analysis of the optimal catalyst distribution in created unsteady state conditions
        Yacine Benguerba Brahim Djellouli Lemnouer Chibane Lahcene Bencheikh
        The determination of the optimal distribution of the catalytic activity profile, whichmaximizes the catalytic effectiveness, in created unsteady state conditions, is analyzed andtreated numerically for the case of a simple reaction. It was proven that the modulation, of أکثر
        The determination of the optimal distribution of the catalytic activity profile, whichmaximizes the catalytic effectiveness, in created unsteady state conditions, is analyzed andtreated numerically for the case of a simple reaction. It was proven that the modulation, of thetemperature and the reactant concentration of the external bulk fluid, leads to a considerableincrease of the catalytic effectiveness. The optimal active element distribution is a Dirac- δfunction i.e. all the catalyst must be deposited at a specific distance from the center of thecatalytic pellet. It was shown that this optimal position changes with time in a sinusoidal manner.This purpose can be achieved by the use of ultrasounds to artificially control the activity profile. تفاصيل المقالة
      • حرية الوصول المقاله

        58 - Thermo-elastic Analysis of Functionally Graded Thick- Walled Cylinder with Novel Temperature – Dependent Material Properties using Perturbation Technique
        Alireza Nadafoskoue hadi mohammadi hooyeh
        In this work, thermo – elastic analysis for functionally graded thick – walled cylinder with temperature - dependent material properties at steady condition is carried out. The length of cylinder is infinite and loading is consist of internal hydrostatic pre أکثر
        In this work, thermo – elastic analysis for functionally graded thick – walled cylinder with temperature - dependent material properties at steady condition is carried out. The length of cylinder is infinite and loading is consist of internal hydrostatic pressure and temperature gradient. All of physical and mechanical properties expect the Poisson's ratio are considered as multiplied an exponential function of temperature and power function of radius. With these assumptions, the nonlinear differential equations for temperature distribution at cylindrical coordinate is obtained. Temperature distribution is achieved by solving this equation using classical perturbation method. With considering strain – displacement, stress – strain and equilibrium relations and temperature distribution that producted pervious, the constitutive differential equation for cylinder is obtained. By employing mechanical boundary condition the radial displacement is yield. With having radial displacement, stresses distribution along the thickness are achieved. The results of this work show that by increasing the order of temperature perturbation series the convergence at curves is occurred and also dimensionless radial stress decrease and other stresses with dimensionless radial displacement increase. تفاصيل المقالة
      • حرية الوصول المقاله

        59 - Stress Analysis of Magneto Thermoelastic and Induction Magnetic Filed in FGM Hallow Sphere
        حسن خادمی زاده علی قربان پور آرانی محمد سالاری
        In this paper a closed form solution for one-dimensional magnetothermoelastic problem in a functionally graded material (FGM) hollow sphere placed in a uniform magnetic field and temperature field subjected to an internal pressure is obtained using the theory of magneto أکثر
        In this paper a closed form solution for one-dimensional magnetothermoelastic problem in a functionally graded material (FGM) hollow sphere placed in a uniform magnetic field and temperature field subjected to an internal pressure is obtained using the theory of magnetothermoelasticity. Hyper-geometric functions are employed to solve the governing equation. The material properties through the graded direction are assumed to be nonlinear with an exponential distribution. The nonhomogeneity of the material in the radial directions is assumed to be power-exponential. The temperature, displacement and stress fields and the perturbation of magnetic field vector are determined and compared with those of the homogeneous case. Hence, the effect of inhomogeneity on the stresses and the perturbation of magnetic field vector distributions are demonstrated. The results of this study are applicable for designing optimum FGM hollow spheres. تفاصيل المقالة

سند

Sanad is a platform for managing Azad University publications

الروابط

المراكز ذات الصلة

دعامة

الصفحات الرسمية

حقوق هذا الموقع الإلكتروني مملوكة لنظام SANAD Press Management. © 1442-1446

الصفحة الرئيسية| دخول| معلومات عنا| اتصل بنا|
[English] [فارسی] [en] [fa]