University of GuilanJournal of Mathematical Modeling2345-394X3120150601SDO relaxation approach to fractional quadratic minimization with one quadratic constraint113198ENMaziarSalahiFaculty of Mathematical Sciences, University of Guilan,Rasht, IranArezoZareFaculty of Mathematical Sciences, University of Guilan,Rasht, IranJournal Article20150609In this paper, we study the problem of minimizing the ratio of two quadratic functions subject to a quadratic constraint. First we introduce a parametric equivalent of the problem. Then a bisection and a generalized Newton-based method algorithms are presented to solve it. In order to solve the quadratically constrained quadratic minimization problem within both algorithms, a semidefinite optimization relaxation approach is presented. Finally, two set of examples are presented to compare the performance of algorithms.https://jmm.guilan.ac.ir/article_198_2afefd8e0fbd7908279afb268bcdcf96.pdfUniversity of GuilanJournal of Mathematical Modeling2345-394X3120150601Dynamical behavior and synchronization of hyperchaotic complex T-system1532196ENHosseinKheiriFaculty of Mathematical Sciences, University of Tabriz, Tabriz, IranBashirNaderiDepartment of Mathematics, Payame Noor University, IranJournal Article20150609In this paper, we introduce a new hyperchaotic complex T-system. This system has complex nonlinear behavior which we study its dynamical properties including invariance, equilibria and their stability, Lyapunov exponents, bifurcation, chaotic behavior and chaotic attractors as well as necessary conditions for this system to generate chaos. We discuss the synchronization with certain and uncertain parameters via adaptive control. For synchronization, we use less controllers than the dimension of the proposed system. Also, we prove that the error system is asymptotically stable by using a Lyapunov function. Numerical simulations are computed to check the analytical expressions.https://jmm.guilan.ac.ir/article_196_8b4648b64fca3b8b5a1909e25a16abaf.pdfUniversity of GuilanJournal of Mathematical Modeling2345-394X3120150601An efficient numerical method for singularly perturbed second order ordinary differential equation3348197ENJugalMohapatraDepartment of Mathematics, National Institute of Technology Rourkela, IndiaManas kumarMahalikDepartment of Mathematics, National Institute of Technology Rourkela, IndiaJournal Article20150609In this paper an exponentially fitted finite difference method is presented for solving singularly perturbed two-point boundary value problems with the boundary layer. A fitting factor is introduced and the model equation is discretized by a finite difference scheme on an uniform mesh. Thomas algorithm is used to solve the tri-diagonal system. The stability of the algorithm is investigated. It is shown that the proposed technique is of first order accurate and the error constant is independent of the perturbation parameter. Several problems are solved and numerical results are presented to support the theoretical error bounds established.https://jmm.guilan.ac.ir/article_197_ce87e8a8bfb327a62b9bc4f0cd2912ba.pdfUniversity of GuilanJournal of Mathematical Modeling2345-394X3120150601Hydromagnetic Couette flow of class-II and heat transfer through a porous medium in a rotating system with Hall effects4975205ENGauriShanker SethDepartment of Applied Mathematics, Indian School of Mines, Dhanbad-826004, IndiaPrashanta KumarMandalDepartment of Applied Mathematics, Indian School of Mines, Dhanbad-826004, IndiaRohitSharmaDepartment of Applied Mathematics, Indian School of Mines, Dhanbad-826004, IndiaJournal Article20150610Steady hydromagnetic Couette flow of class-II of a viscous, incompressible and electrically conducting fluid through a porous medium in a rotating system taking Hall current into account is investigated. Heat transfer characteristics of the fluid flow are considered taking viscous and Joule dissipations into account. It is noticed that there exists flow separation at the moving plate in the secondary flow direction on increasing either rotation parameter $K^2$ when Hall current parameter $m = 0.5$ or $m$ when $K^2 = 7$. Also there exists flow separation at the moving plate in the secondary flow direction on increasing either magnetic parameter $M^2$ for every value of porosity parameter $K_1$ or $K_1$ when $M^2 = 15$.https://jmm.guilan.ac.ir/article_205_9dfc74ef6cd9798bedaed2a07880d060.pdfUniversity of GuilanJournal of Mathematical Modeling2345-394X3120150601Bernoulli matrix approach for matrix differential models of first-order7789201ENAhmadGolbabaiSchool of Mathematics, Iran University of Science and Technology, Tehran, IranSamanehPanjeh Ali BeikSchool of Mathematics, Iran University of Science and Technology, Tehran, IranJournal Article20150609The current paper contributes a novel framework for solving a class of linear matrix differential equations. To do so, the operational matrix of the derivative based on the shifted Bernoulli polynomials together with the collocation method are exploited to reduce the main problem to system of linear matrix equations. An error estimation of presented method is provided. Numerical experiments are reported to demonstrate the applicably and efficiency of the propounded technique.https://jmm.guilan.ac.ir/article_201_603705fa691297a3e173ef4db4941979.pdfUniversity of GuilanJournal of Mathematical Modeling2345-394X3120150601Determining the order of minimal realization of descriptor systems without use of the Weierstrass canonical form91101199ENKameleNassiri PirbazariFaculty of Mathematical Sciences, University of Guilan, Rasht, IranMehdiAzariFaculty of Mathematical Sciences, University of Guilan, Rasht, IranJournal Article20150609A common method to determine the order of minimal realization of a continuous linear time invariant descriptor system is to decompose it into slow and fast subsystems using the Weierstrass canonical form. The Weierstrass decomposition should be avoided because it is generally an ill-conditioned problem that requires many complex calculations especially for high-dimensional systems. The present study finds the order of minimal realization of a continuous linear time invariant descriptor system without use of the Weierstrass canonical form.https://jmm.guilan.ac.ir/article_199_73509e717ef96f2eab01c1417ed30360.pdf