SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Combined effect of suspended particles and rotation on thermosolutal convection in a viscoelastic fluid saturating a Darcy-Brinkman porous medium319325163010.22099/ijsts.2013.1630ENG. C. RanaDepartment of Mathematics, NSCBM Govt. P. G. College, Hamirpur-177 005, Himachal PradeshR. C. ThakurDepartment of Mathematics, Govt. P. G. College, Dhaliara, Kangra-177 103, Himachal Pradesh, IndiaJournal Article20120421In this paper, the combined effect of suspended (fine dust) particles and rotation on the onset of thermosolutal convection in an elastico-viscous fluid in a porous medium is studied. For the porous medium, the Brinkman model is employed and Rivlin-Ericksen model is used to characterize viscoelastic fluid. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the rotation, stable solute gradient, suspended particles, gravity field and viscoelasticity introduce oscillatory modes. For stationary convection, it is observed that the rotation, stable solute gradient have a stabilizing effect and suspended particles have a destabilizing effect on the system whereas Darcy number and medium permeability have stabilizing/destabilizing effects under certain conditions. The effects of rotation, stable solute gradient, suspended particles, Darcy number and medium permeability have also been shown graphically.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Approximation of stochastic advection-diffusion equation
using compact finite difference technique327333163110.22099/ijsts.2013.1631ENM. BishehniasarDepartment of Mathematics, University of Sistan and Baluchestan Zahedan, IranA. R. SoheiliThe Center of Excellence on Modeling and Control Systems,
Department of applied Mathematics, School of Mathematical science,
Ferdowsi University of Mashhad, MashhadJournal Article20120512In this paper, we propose a new method for solving the stochastic advection-diffusion equation of Ito type. In this work, we use a compact finite difference approximation for discretizing spatial derivatives of the mentioned equation and semi-implicit Milstein scheme for the resulting linear stochastic system of differential equation. The main purpose of this paper is the stability investigation of the applied method. Finally, some numerical examples are provided to show the accuracy and efficiency of the proposed technique.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Bayesian and non-bayesian estimation of stress–strength
model for Pareto type I distribution335342163210.22099/ijsts.2013.1632ENA. I. ShawkyDepartment of Statistics, Faculty of Sciences, King Abdulaziz University,
P.O. Box 80203, Jeddah 21589F. H. Al-GashgariDepartment of Statistics, Faculty of Sciences for Girls, King Abdulaziz University,
P.O. Box 53873, Jeddah 21593, Saudi ArabiaJournal Article20120501This article examines statistical inference for where and are independent but not identically distributed Pareto of the first kind (Pareto (I)) random variables with same scale parameter but different shape parameters. The Maximum likelihood, uniformly minimum variance unbiased and Bayes estimators with Gamma prior are used for this purpose. Simulation studies which compare the estimators are presented. Moreover, sensitivity of Bayes estimator to the prior parameters is considered.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916On BC-generalized Landsberg Finsler metrics343347163310.22099/ijsts.2013.1633ENM. ZamanzadehBijar Branch, Islamic Azad University BijarB. NajafiDepartment of Mathematics, Faculty of Science, Shahed University of Tehran, Tehran, IranJournal Article20121003Equality of -curvatures of the Berwald and Cartan connections leads to a new class of Finsler metrics, so-called BC-generalized Landsberg metrics. Here, we prove that every BC-generalized Landsberg metric of scalar flag curvature with dimension greater than two is of constant flag curvature.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916A preemptive restarting approach to beating the
inherent instability of Lanczos-type algorithms349358163410.22099/ijsts.2013.1634ENM. FarooqDepartment of Mathematics, University of Peshawar, 25120, Khyber PakhtunkhwaA. SalhiDepartment of Mathematical Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UKJournal Article20120723Lanczos-type algorithms are well known for their inherent instability. They typically breakdown occurs when relevant orthogonal polynomials do not exist. Current approaches to curing breakdown rely on jumping over the non-existent polynomials to resume computation. This may have to be used many times during the solution process. We suggest an alternative to jumping, which consists of restarting the algorithms that fail. Three different strategies can be taken: (ST1) Restarting following breakdown of the algorithm in use; (ST2) pre-emptive restarting after a fixed number of iterations; (ST3) restarting when near breakdown is detected through monitoring. We describe a restarting framework with a generic algorithm that invokes one or the other of the three strategies suggested. Four of the most prominent recently developed Lanczos-type algorithms namely, and will be presented and then deployed in the restarting framework. However, we will only report on results obtained with strategy ST2 as it is the only viable one at the moment.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Symplectic Hodge theory, harmonicity, and Thom duality359363163510.22099/ijsts.2013.1635ENM. BahramgiriGraduate School of Management and Economics Sharif University of TechnologyJournal Article20120307We study the notion of harmonicity in the sense of symplectic geometry, and investigate the geometric properties of harmonic Thom forms and distributional Thom currents, dual to different types of submanifolds. We show that the harmonic Thom form associated to a symplectic submanifold is nowhere vanishing. We also construct symplectic smoothing operators which preserve the harmonicity of distributional currents and using these operators, construct harmonic Thom forms for co-isotropic submanifolds, which unlike the harmonic forms associated with symplectic submanifolds, are supported in an arbitrary tubular neighborhood of the manifold.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Some kinds of -fuzzy ideals of ternary semigroups365378163610.22099/ijsts.2013.1636ENN. RehmanDepartment of Basic Sciences, Riphah International University, Islamabad, PakistanM. Shabir2Department of Mathematics, Quaid-i-Azam University, Islamabad, PakistanJournal Article20121222Generalizing the concepts of -fuzzy (left, right, lateral) ideals, -fuzzy quasi-ideals and -fuzzy bi (generalized bi-) ideals in ternary semigroups, the notions of -fuzzy (left, right, lateral) ideals, -fuzzy quasi-ideals and -fuzzy bi (generalized bi-) in ternary semigroups are introduced and several related properties are investigated. Some new results are obtained.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916An optimal control approach for arbitrary order
singularly perturbed boundary value problems379388163710.22099/ijsts.2013.1637ENM. ZarepourDepartment of Mathematics, Yazd University, P.O. Box: 89195-741 Yazd, IranG. B. LoghmaniDepartment of Mathematics, Yazd UniversityJournal Article20121003The aim of this paper is to introduce a new approach for obtaining the numerical solution of singulary perturbed boundary value problems based on an optimal control technique. In the proposed method, first the mentioned equations are converted to an optimal control problem. Then, control and state variables are approximated by Chebychev series. Therefore, the optimal control problem is reduced to a parametric optimal control problem (POC) subject to algebric constraints. Finally, the obtained POC is solved numerically using an iterative optimization technique. In this method, a new idea is proposed which enables us to apply the new technique for almost all kinds of singularly perturbed boundary value problems. Some numerical examples are solved to highlight the advantages of the proposed technique.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Boundary layer problem for system of first order of ordinary differential equations with linear non-local boundary conditions389396163810.22099/ijsts.2013.1638ENM. JahanshahiDepartment of Mathematics, Azarbaijan Shahid Madani University, 5375171379, TabrizA. R. SarakhsiDepartment of Mathematics, Azarbaijan Shahid Madani University, 5375171379, Tabriz, IranS. AsharafiDepartment of Mathematics, Azarbaijan Shahid Madani University, 5375171379, Tabriz, IranN. AlievDepartment of Mathematics, Baku State University, Baku, AzerbaijanJournal Article20120808In this paper we study the boundary layer problems in which boundary conditions are non-local. Here we try to find the necessary conditions by the help of fundamental solution to the given adjoint equation. By getting help from these conditions, at first the boundary condition is changed from non-local to local. The main aim of this paper is to identify the location of the boundary layer. In other words, at which point the boundary layer is formed.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916On generalized I-statistical convergenceof order397402163910.22099/ijsts.2013.1639ENE. SavasDepartment of Mathematics, Istanbul Commerce University, Uskudar-IstanbulJournal Article20120911The goal of this paper is to generalize the recently introduced summability method and introduce double statistical convergence of order by using ideal. We also investigate certain properties of this convergence.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916On characterization of spacelike dual biharmonic curves
in dual Lorentzian Heisenberg group403410164010.22099/ijsts.2013.1640ENT. KorpinarDepartment of Mathematics, Mus Alparslan University, 49250, Mus, TurkeyE. TurhanDepartment of Mathematics, Firat University, 23119, Elazig, TurkeyV. Asil3Department of Mathematics, Firat University, 23119, ElazigJournal Article20110613In this paper, we study spacelike dual biharmonic curves. We characterize spacelike dual biharmonic curves in terms of their curvature and torsion in the Lorentzian dual Heisenberg group . We give necessary and sufficient conditions for spacelike dual biharmonic curves in the Lorentzian dual Heisenberg group . Therefore, we prove that all spacelike dual biharmonic curves are spacelike dual helix. Moreover, we give their explicit parametrizations of spacelike dual biharmonic curves. Finally, we illustrate our main results in Figs. 1 and 2.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916Graded prime spectrum of a graded module411420164110.22099/ijsts.2013.1641ENN. A. OzkiırisciDepartment of Mathematics, Faculty of Arts and Science, Yildiz
Technical University, 34210, Esenler, IstanbulK. H. OralDepartment of Mathematics, Faculty of Arts and Science, Yildiz
Technical University, 34210, Esenler, Istanbul, TurkeyU. TekirDepartment of Mathematics, Faculty of Arts and Science, Marmara University, 34722, Goztepe, Istanbul, TurkeyJournal Article20121014Let be a graded ring and be a graded -module. We define a topology on graded prime spectrum of the graded -module which is analogous to that for , and investigate several properties of the topology.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916The multi-step homotopy analysis method: A powerful
scheme for handling non-linear oscillators421429164210.22099/ijsts.2013.1642ENM. ZurigatDepartment of Mathematics, Al al-Bayt University, Mafraq, JordanS. Al-SharaDepartment of Mathematics, Al al-Bayt University, Mafraq, JordanS. MomaniDepartment of Mathematics, University of Jordan, AmmanA. AlawnehDepartment of Mathematics, University of Jordan, Amman, JordanJournal Article20110927This paper presents approximate analytical solutions for nonlinear oscillators using the multi-step homotopy analysis method (MSHAM). The proposed scheme is only a simple modification of the homotopy analysis method, in which it is treated as an algorithm in a sequence of small intervals (i.e. time step) for finding accurate approximate solutions to the corresponding problems. Several illustrative examples are given to demonstrate the effectiveness of the present method. Figurative comparisons between the MSHAM and the classical fourth-order Runge-Kutta method (RK4) reveal that this modified method is very effective and convenient.SpringerIranian Journal of Science and Technology (Sciences)1028-6276373.120130916A system of generalized resolvent equations involving
generalized pseudocontractive mapping431438164310.22099/ijsts.2013.1643ENR. AhmadDepartment of Mathematics, Aligarh Muslim University, Aligarh-202002, IndiaM. AkramDepartment of Mathematics, Aligarh Muslim University, Aligarh-202002Journal Article20120728Generalized resolvent equations; variational inclusions; algorithm; convergence; generalized pseudocontractive mapping