@article { author = {Rana, G. C. and Thakur, R. C.}, title = {Combined effect of suspended particles and rotation on thermosolutal convection in a viscoelastic fluid saturating a Darcy-Brinkman porous medium}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {319-325}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1630}, abstract = {In 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.}, keywords = {Brinkman porous medium,Rivlin-Ericksen fluid,rotation,suspended particles,thermosolutal convection,Viscosity,viscoelasticity}, url = {https://ijsts.shirazu.ac.ir/article_1630.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1630_6ad4ef4ca441fd758f0ca9b39f9312d5.pdf} } @article { author = {Bishehniasar, M. and Soheili, A. R.}, title = {Approximation of stochastic advection-diffusion equation using compact finite difference technique}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {327-333}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1631}, abstract = {In 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.}, keywords = {Stochastic partial differential equation,compact finite difference scheme,Stability,semi-implicit Milstein method}, url = {https://ijsts.shirazu.ac.ir/article_1631.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1631_22e92753f3dad7596b3b82cbc3100358.pdf} } @article { author = {Shawky, A. I. and Al-Gashgari, F. H.}, title = {Bayesian and non-bayesian estimation of stress–strength model for Pareto type I distribution}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {335-342}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1632}, abstract = {This 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.}, keywords = {Bayesian estimator,Maximum likelihood estimator (MLE),Pareto of first kind,uniformly minimum variance unbiased estimator (UMVUE),stress-strength model}, url = {https://ijsts.shirazu.ac.ir/article_1632.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1632_bc2d251569304a0afdc39c565a46af4b.pdf} } @article { author = {Zamanzadeh, M. and Najafi, B.}, title = {On BC-generalized Landsberg Finsler metrics}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {343-347}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1633}, abstract = {Equality 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.}, keywords = {Finsler structure,Landsberg metric,generalized Landsberg metric,scalar flag curvature}, url = {https://ijsts.shirazu.ac.ir/article_1633.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1633_c8dcd51ee11af2c9a5cef5d64ae37a05.pdf} } @article { author = {Farooq, M. and Salhi, A.}, title = {A preemptive restarting approach to beating the inherent instability of Lanczos-type algorithms}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {349-358}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1634}, abstract = {Lanczos-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.}, keywords = {Lanczos algorithm,Systems of Linear Equations,Formal Orthogonal Polynomials, Restarting, Switching, Breakdown}, url = {https://ijsts.shirazu.ac.ir/article_1634.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1634_6f943b0d0733d9fee2c5c1cae69b892c.pdf} } @article { author = {Bahramgiri, M.}, title = {Symplectic Hodge theory, harmonicity, and Thom duality}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {359-363}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1635}, abstract = {We 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.}, keywords = {Harmonicity,duality,Thom class,Hodge theory,symplectic,distributional currents,smoothing operators,oriented submanifold}, url = {https://ijsts.shirazu.ac.ir/article_1635.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1635_1a20b2d7b1e35b156f03b7bb2f5ad63e.pdf} } @article { author = {Rehman, N. and Shabir, M.}, title = {Some kinds of -fuzzy ideals of ternary semigroups}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {365-378}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1636}, abstract = {Generalizing 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.}, keywords = {Ternary semigroups,-fuzzy ideals,-fuzzy quasi-ideals,-fuzzy ideals bi-ideals}, url = {https://ijsts.shirazu.ac.ir/article_1636.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1636_9f7826714c3ad66e4cae9235cc70f2ce.pdf} } @article { author = {Zarepour, M. and Loghmani, G. B.}, title = {An optimal control approach for arbitrary order singularly perturbed boundary value problems}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {379-388}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1637}, abstract = {The 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.}, keywords = {Singularly perturbed boundary value problem,parametric optimal control,Optimal control problem}, url = {https://ijsts.shirazu.ac.ir/article_1637.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1637_a9995d56a60e51847fb33cd32294b719.pdf} } @article { author = {Jahanshahi, M. and Sarakhsi, A. R. and Asharafi, S. and Aliev, N.}, title = {Boundary layer problem for system of first order of ordinary differential equations with linear non-local boundary conditions}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {389-396}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1638}, abstract = {In 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.}, keywords = {Singular perturbation problems,boundary layer,fundamental solution,necessary conditions}, url = {https://ijsts.shirazu.ac.ir/article_1638.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1638_138c842f9ce699a3b1ca11ff19b5855a.pdf} } @article { author = {Savas, E.}, title = {On generalized I-statistical convergenceof order}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {397-402}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1639}, abstract = {The 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.}, keywords = {ideal,filter,I- double statistical convergence of order α,I_λ- double statistical convergence of order α, closed subspace}, url = {https://ijsts.shirazu.ac.ir/article_1639.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1639_5c4780979b216e7f063511e6a922a483.pdf} } @article { author = {Korpinar, T. and Turhan, E. and Asil, V.}, title = {On characterization of spacelike dual biharmonic curves in dual Lorentzian Heisenberg group}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {403-410}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1640}, abstract = {In 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.}, keywords = {Bienergy,biharmonic curve,Helix,Heisenberg group}, url = {https://ijsts.shirazu.ac.ir/article_1640.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1640_c99b982ac35eddb02110b1791a7b0378.pdf} } @article { author = {Ozkiırisci, N. A. and Oral, K. H. and Tekir, U.}, title = {Graded prime spectrum of a graded module}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {411-420}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1641}, abstract = {Let  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.}, keywords = {Graded module,graded prime spectrum,graded prime submodule}, url = {https://ijsts.shirazu.ac.ir/article_1641.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1641_2c038b0eafc3b894e8058709f74ed513.pdf} } @article { author = {Zurigat, M. and Al-Shara, S. and Momani, S. and Alawneh, A.}, title = {The multi-step homotopy analysis method: A powerful scheme for handling non-linear oscillators}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {421-429}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1642}, abstract = {This 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.}, keywords = {Non-linear oscillators,homotopy analysis method,numerical solutions}, url = {https://ijsts.shirazu.ac.ir/article_1642.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1642_70909ef1ebb1fef861842127d76a1c61.pdf} } @article { author = {Ahmad, R. and Akram, M.}, title = {A system of generalized resolvent equations involving generalized pseudocontractive mapping}, journal = {Iranian Journal of Science}, volume = {37}, number = {3.1}, pages = {431-438}, year = {2013}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2013.1643}, abstract = {Generalized resolvent equations; variational inclusions; algorithm; convergence; generalized pseudocontractive mapping}, keywords = {Generalized resolvent equations,variational inclusions,algorithm,convergence,generalized pseudocontractive mapping}, url = {https://ijsts.shirazu.ac.ir/article_1643.html}, eprint = {https://ijsts.shirazu.ac.ir/article_1643_65e5be04ad85dbab8e469418090b76a7.pdf} }