فهرست مطالب

  • Volume:38 Issue:3, 2014
  • Special issue-Mathematics-A3
  • تاریخ انتشار: 1393/07/22
  • تعداد عناوین: 12
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  • A. Neamaty* Pages 305-309
    The purpose of this paper is to investigate the inverse problem for a second order differential equation the socalled differential pencil on the finite interval 􁈾0,1􁈿 when the solutions are not smooth. We establish properties of the spectral characteristics, derive the Weyl function and prove the uniqueness theorem for this inverse problem.
    Keywords: Inverse problem, differential pencil, jump condition, Weyl function
  • S. Medhit* Pages 311-320
    The main objective of this study is to swing Krull intersection theorem in primary decomposition of rings and modules to the primary decomposition of soft rings and soft modules. To fulfill this aim several notions like soft prime ideals, soft maximal ideals, soft primary ideals, and soft radical ideals are introduced for a soft ring over a given unitary commutative ring. Consequently, the primary decomposition of soft rings and soft modules is established. In addition, the ascending and descending chain conditions on soft ideals and soft sub modules of soft rings and soft modules are introduced, respectively, enabling us to develop the notions of soft Noetherian rings and soft Noetherian modules.
    Keywords: Primary decomposition, soft Noetherian ring (module), soft primary module, minimal soft prime ideal, soft irreducible ideal
  • R. Farnoosh Pages 321-327
    In this article, the discrete time state space model with first-order autoregressive dependent process noise is considered and the recursive method for filtering, prediction and smoothing of the hidden state from the noisy observation is designed. The explicit solution is obtained for the hidden state estimation problem. Finally, in a simulation study, the performance of the designed method for discrete time state space model with dependent process noise is verified.
    Keywords: State space model, dependent process noise, estimation of the hidden state, estimation of the error covariance
  • A. R. Soheili* Pages 329-336
    This paper introduces a mesh generating algorithm for solving the traffic flow equation as a conservation law equation. The idea behind the new method is to use the characteristic curves and moving non-oscillatory finite volume method. In addition, when characteristic curves intersect, the proposed scheme uses shock speed equation in order to improve computational efficiency. We also compare the obtained results with the corresponding solutions computed by the moving mesh method.
    Keywords: Traffic flow, characteristic curves, shock speed, moving finite volume method
  • H. Haj Seyyed Javadi* Pages 337-342
    In this paper, we introduce the concept of the generalized AIP-rings as a generalization of the generalized quasi- Baer rings and generalized p.p.-rings. We show that the class of the generalized AIP-rings is closed under direct products and Morita invariance. We also characterize the 2-by-2 formal upper triangular matrix rings of this new class of rings. Finally, we provide several examples to show the applicability and limitation of this class of rings.
    Keywords: Baer rings, quasi, Baer rings, p.p., rings, annihilators, idempotent, s, unital ideal
  • M. Sanjaranipour* Pages 343-348
    In this paper, the deformation of a thick-walled circular cylindrical shell of incompressible isotropic elastic material is considered. The shell, which is made of Three-Term strain energy function is subjected to the combined external and axial loading pressure. In order to obtain the relevant eigenvalues, which is the main objective of the work, the incremental equilibrium equations are solved with two numerical, i.e. Adams-Moulton and Compound matrix methods. Finally the bifurcation behavior is investigated by plotting the radius changes with respect to the changes of the length of the cylinder.
    Keywords: Compound matrix method, Adams, Moulton method, eigenvalues, axisymmetric bifurcation
  • S. M. Dehnavi Pages 349-353
    The square map is one of the functions used in cryptography. For instance, the square map is used in Rabin encryption scheme, block cipher RC6 and stream cipher Rabbit, in different forms. In this paper, we study statistical properties of the output of the square map as a vectorial Boolean function. We obtain the joint probability distribution of arbitrary number of the upper and the lower bits of the output of square map along with the asymptotic probability distribution of the upper bits of its output. Based upon a measure for evaluating the imbalance of maps, we study the imbalance of limit distribution of the restriction of square map to its upper bits. Last, we introduce the square root map and examine this map as a vectorial Boolean function; we compute probability distribution of the component Boolean functions of this new map and also obtain the imbalance of the square root map.
    Keywords: Square Map, square root map, vectorial boolean function, component boolean function, asymptotic probability distribution
  • H. R. Z. Zangeneh* Pages 355-364
    By using bifurcation theory of planar ordinary differential equations all different bounded travelling wave solutions of the Generalized Zakharov equation are classified in different parametric regions. In each of these parametric regions the exact explicit parametric representation of all solitary, kink (anti kink) and periodic wave solutions as well as their numerical simulation and their corresponding phase portraits are obtained.
    Keywords: Generalized Zakharov equation, travelling wave solutions, Bifurcation theory
  • R. Tuntas* Pages 365-372
    In the present study, a new modelling technique was developed for the modelling and analysis of hyperchaotic systems using an expert system based on wavelet decompositions and the Adaptive Neuro-Fuzzy Inference System (ANFIS). The success and superior properties of this new expert system were shown by applying the hyperchaotic Chen system which is a hyperchaotic system. The obtained expert system consists of two layers, including wavelet decomposition and ANFIS. Wavelet decomposition was used for extracting features in the first layer, and ANFIS was used for system modelling in second layer. Furthermore, HSPICE simulation of the hyperchaotic Chen system was carried out for comparison with the proposed expert system. The structure of the ANFIS was improved and trained in the MATLAB toolbox. Numerical simulations were used in this study. Five various data sets have been used to test the simulation speed of the proposed expert system and HSPICE. The obtained results show that the proposed expert system simulation has much higher speed and accuracy in comparison with HSPICE simulation. The proposed expert system can be simply used in software tools for the design and simulation of the hyperchaotic Chen system and other hyperchaotic systems.
    Keywords: Expert system, wavelet decomposition, ANFIS, hyperchaotic Chen system
  • A. El-Abed* Pages 373-377
    In this work, different types of chaotic 1-manifolds which lie on the chaotic spheres or on a torus are introduced. Some types of retractions of the chaotic spheres affect on the 1-chaotic systems, and other types of retractions occur to the geometric manifold but make the 1-chaotic manifold invariant. The existed retractions are discussed through new proved theorems. Also we construct different types of folding of 1-chaotic manifolds which are homeomorphic to S1and their indicatrixes.
    Keywords: Chaotic, manifolds, folding, retraction, geodesics
  • G. Deepa* Pages 379-388
    An analysis is carried out to investigate the effects of variable chemical reaction, thermophoresis, temperaturedependent viscosity and thermal radiation on an unsteady MHD free convective heat and mass transfer flow of a viscous, incompressible, electrically conducting fluid past an impulsively started infinite inclined porous plate by taking into account the viscous dissipation effects. The governing nonlinear partial differential equations are transformed into a system of ordinary differential equations, which are solved numerically by using implicit finite difference scheme with shooting method. Numerical results for the non-dimensional velocity, temperature and concentration profiles as well as the local skin-friction coefficient, the local Nusselt number and the local Stanton number are presented for different physical parameters. The results show that variable viscosity significantly increases viscous drag and rate of heat transfer. The results also show that higher order chemical reaction induces the concentration of the particles for a destructive reaction and reduces for a generative reaction.
    Keywords: Variable viscosity, chemical reaction, thermophoresis, MHD, thermal radiation, finite difference scheme, viscous dissipation