Theory of Approximation and ApplicationsTheory of Approximation and Applications
http://msj.iau-arak.ac.ir/
Sat, 17 Aug 2019 18:44:20 +0100FeedCreatorTheory of Approximation and Applications
http://msj.iau-arak.ac.ir/
Feed provided by Theory of Approximation and Applications. Click to visit.Domination Number of Nagata Extension Ring
http://msj.iau-arak.ac.ir/article_546274_116543.html
Aََََbstract:Let R is a commutative ring whit Z(R) as the set of zero divisors. The total graph of R, denoted by T ((R)) is the (undirected) graph with all elements of R as vertices, and two distinct vertices are adjacent if their sum is a zero divisor. For a graph G = (V; E), a set S is a dominating set if every vertex in V n S is adjacent to a vertex in S. The domination number is equal |S|where |S| is minimum. For R-module M, an Nagata extension (idealization), denoted by R(+)M is a ring with identity and for two elements (r; m); (s; n) of R(+)M we have (r; m) + (s; n) = (r + s; m + n) and (r; m)(s; n) = (rs; rn + sm). In this paper, we seek to determine the bound for the domination number of total graph T ((R(+)M)).Thu, 28 Feb 2019 20:30:00 +0100Construction of α-cut fuzzy X ̅ control charts based on standard deviation and range using ...
http://msj.iau-arak.ac.ir/article_664501_0.html
Control charts are one of the most important tools in statistical process control that lead to improve quality processes and ensure required quality levels. In traditional control charts, all data should be exactly known, whereas there are many quality characteristics that cannot be expressed in numerical scale, such as characteristics for appearance, softness, and color. Fuzzy sets theory is a powerful mathematical approach to analyze uncertainty, ambiguous and incomplete that can linguistically define data in these situations. Fuzzy control charts have been extended by converting the fuzzy sets associated with linguistic or uncertain values into scalars regarded as representative values. In this paper, we study two different approaches to construct X ̅ control chart, when the observations are fuzzy number. Two methods of defuzzification for calculating the value representing sample means and for determining the control chart limits are presented. In the second approach α-cut control chart for variable are developed using upper control limits and lower control limits. The article also presents a fuzzy decision for in control or out of control of the process, in which membership degrees of in and out of control states of process mean is computed.Wed, 24 Apr 2019 19:30:00 +0100Fuzzy Farthest Points and Fuzzy Best Approximation Points in Fuzzy Normed Spaces
http://msj.iau-arak.ac.ir/article_546275_116543.html
In this paper we define fuzzy farthest points, fuzzy best approximation points and farthest orthogonality in fuzzy normed spaces and we will find some results. We prove some existence theorems, also we consider fuzzy Hilbert and show every nonempty closed and convex subset of a fuzzy Hilbert space has an unique fuzzy best approximation.It is well know that the conception of fuzzy sets, firstly defined by Zadeh in 1965. Fuzzy set theory provides us with a framework which is wider than that of classical set theory. Various mathematical structures, whose features emphasize the effects of ordered structure, can be developed on the theory. The theory of fuzzy sets has become an area of active research for the last forty years. On the other hand, the notion of fuzzyness has a wide application in many areas of science and engineering, chaos control, nonlinear dynamical systems, etc. In physics, for example, the fuzzy structure of space time is followed by the fat that in strong quantum gravity regime space time points are determined in a fuzzy manner.Thu, 28 Feb 2019 20:30:00 +0100Numerical Solution of the Burgers' Equation Based on Sinc Method
http://msj.iau-arak.ac.ir/article_663606_116543.html
Burgers' equation arises in various areas of applied mathematics,‎‎such as modeling of dynamics‎, ‎heat conduction‎, ‎and acoustic‎‎waves‎ Also‎, ‎this equation has a large variety of applications in‎‎the modeling of water in unsaturated soil‎, ‎dynamics of soil‎‎water‎, ‎models of traffic‎, ‎turbulence and fluid flow‎, ‎mixing and‎‎turbulent diffusion. Many researchers tried to find analytic and numerical solutions of‎‎ this equation by different methods.Sinc method is a powerful numerical tool for finding fast and‎‎accurate solution in various areas of problems.‎In this paper‎, ‎numerical solution of Burgers' equation‎‎is considered by applying Sinc method‎. ‎For this purpose‎, ‎we apply‎‎Sinc method in cooperative with a classic finite difference‎‎formula to‎ ‎Burgers'equation‎. ‎‎The purpose of this paper is to extend the application of the‎‎sinc method for solving Burgers'equation by considering stability‎‎analysis of the method.‎ Numerical examples are provided to verify the validity of proposed methodThu, 28 Feb 2019 20:30:00 +0100Measurement of Inefficiency Slacks in Network Data Envelopment Analysis
http://msj.iau-arak.ac.ir/article_663609_116543.html
The two-stage data envelopment analysis models show the performance of individual processes and ‎thus, provide more information for decision-making compared with conventional one-stage models. ‎This article presents a set of additive models (optimistic and pessimistic) to measure inefficiency ‎slacks in which observations are shown with crisp numbers. In the concept of pessimistic efficiency, ‎DMU with balanced input and output data can be scored as efficient. Since pessimistic efficiency ‎represents the minimum efficiency that is guaranteed in any unfavorable conditions, the assessment ‎based on this efficiency is in compliance with our natural meaning, especially in risk-averse situations. ‎Therefore, pessimistic efficiency solely can play a useful role in the DMU ranking. However, it is not ‎a good idea to ignore optimistic efficiency. Hence, it is an inevitable necessity to integrate different ‎performance sizes in order to achieve an overall performance assessment for each DMU. An example ‎of resin manufacturer companies in Iran is presented to explain how to calculate the system and ‎process inefficiency slacks.‎Thu, 28 Feb 2019 20:30:00 +0100Constacyclic Codes over Group Ring (Zq[v])/G
http://msj.iau-arak.ac.ir/article_663607_0.html
Recently, codes over some special ﬁnite rings especially chain rings have been studied. More recently, codes over ﬁnite non-chain rings have been also considered. Study on codes over such rings or rings in general is motivated by the existence of some special maps called Gray maps whose images give codes over ﬁelds. Quantum error-correcting (QEC) codes play a crucial role in protecting quantum information. The construction of quantum codes via classical codes over 2 F was ﬁrst introduced by Calderbank and Shor [4] and Steane [13] in 1996. This method, known as CSS construction, has received a lot of attention and it has allowed to ﬁnd many good quantum stabilizer codes. Later, construction of quantum codes over larger alphabets from classical linear codes over q F has shown by Ketkar et al. in [10]. One direction of the main research in quantum error correction codes is constructing quantum codes that have large minimum distances [9] for a given size and length. In [14], based on classical quaternary constacyclic linear codes, some parameters for quantum codes are obtained. In [8, 9], respectively based on classical negacyclic and constacyclic linear codes some parameters for quantum MDS codes are presented. In this work, we determine self-dual and self-orthogonal codes arising from constacyclic codes over the group ring(Zq[v]/GThu, 28 Feb 2019 20:30:00 +0100Spectral method for Solving Fuzzy Volterra Integral Equations of Second kind
http://msj.iau-arak.ac.ir/article_663608_116543.html
This paper, about the solution of fuzzy Volterra integral equation of fuzzy Volterra integral equation of second kind (F-VIE2) using spectral method is discussed. The parametric form of fuzzy driving term is applied for F-VIE2. Then three cases for (F-VIE2) are searched to solve them. This classifications are considered based on the sign of interval. The Gauss-Legendre points and Legendre weights for arithmetics in spectral method are used to solve (F-VIE2). Finally two examples are got to illustrate more.b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b bThu, 28 Feb 2019 20:30:00 +0100On Best Proximity Points in metric and Banach spaces
http://msj.iau-arak.ac.ir/article_666924_0.html
Notice that best proximity point results have been studied to find necessaryconditions such that the minimization problemminx∈A∪Bd(x,Tx)has at least one solution, where T is a cyclic mapping defined on A∪B.A point p ∈ A∪B is a best proximity point for T if and only if thatis a solution of the minimization problem (2.1). Let (A,B) be a nonemptypair in a normed linear space X and S,T : A∪B → A∪B be two cyclicmappings. Let (A,B) be a nonempty pair in a normed linear space X andS,T : A∪B → A∪B be two cyclic mappings. A point p ∈ A∪B is called acommon best proximity point for the cyclic pair (T,S) provided that∥p − Tp∥ = d(A,B) = ∥p − Sp∥In this paper, we survey the existence, uniqueness and convergence of a com-mon best proximity point for a cyclic weak ST − ϕ-contraction map, whichis equivalent to study of a solution for a nonlinear programming problem inthe setting of uniformly convex Banach spaces. We will provide examples toillustrate our results.Wed, 07 Aug 2019 19:30:00 +0100The Iterative Method for Solving Non-Linear Equations
http://msj.iau-arak.ac.ir/article_664208_116543.html
In this paper, we have combined the ideas of the False Position (FP) and Artificial Bee Colony (ABC) algorithms to find a fast and novel method for solving nonlinear equations. Additionally, to illustrate the efficiency of the proposed method, several benchmark functions are solved and compared with other methods such as ABC, PSO and GA.Thu, 28 Feb 2019 20:30:00 +0100Sequential Optimality Conditions and Variational Inequalities
http://msj.iau-arak.ac.ir/article_666925_0.html
In recent years, sequential optimality conditions are frequently used for convergence of iterative methods to solve nonlinear constrained optimization problems. The sequential optimality conditions do not require any of the constraint qualications. In this paper, We present the necessary sequential complementary approximate Karush Kuhn Tucker (CAKKT) condition for a point to be a solution of a nonlinear optimization problem. The nonlinear optimization problem is associated with the variational inequality problem. We also extend the complementary approximate Karush Kuhn Tucker condition from scalar optimization problem to multiobjective optimization problem and associated with the vector variational inequality problem. Further, we prove that with some extra conditions of convexity and affinity, complementary approximate Karush Kuhn Tucker conditions are sufficient for the variational inequality problem and vector variational inequality problem. Finally, we verify our results via illustrative examples. An example shows that a point which is a solution of variational inequality problem is also a CAKKT point.Wed, 07 Aug 2019 19:30:00 +0100A Second-Order Accurate Numerical Approximation for Two-Sided Fractional Boundary Value ...
http://msj.iau-arak.ac.ir/article_664232_116543.html
Fractional order partial differential equations are generalization of classical partialdifferential equations. Increasingly, these models are used in applications such as fluid flow, financeand others. In this paper we examine some practical numerical methods to solve a class of initial-boundary value fractional partial differential equations with variable coefficients on a finite domain. An approach based on the classical Crank-Nicolson method combined with spatial extrapolation is used to obtain temporally and spatially second-order accurate numerical estimates. Stability, consistency, and convergence of the method are examined. It is shown that the fractional Crank-Nicolson method based on the shifted Gr"{u}nwaldformula is unconditionally stable. Some numerical examples are presented and compared with the exact analytical solutionfor its order of convergence.Fractional order partial differential equations are generalization of classical partialdifferential equations. Increasingly, these models are used in applications such as fluid flow, financeand others. In this paper we examine some practical numerical methods to solve a class of initial-boundary value fractional partial differential equations with variable coefficients on a finite domain. An approach based on the classical Crank-Nicolson method combined with spatial extrapolation is used to obtain temporally and spatially second-order accurate numerical estimates. Stability, consistency, and convergence of the method are examined. It is shown that the fractional Crank-Nicolson method based on the shifted Gr"{u}nwaldformula is unconditionally stable. Some numerical examples are presented and compared with the exact analytical solutionfor its order of convergence.Thu, 28 Feb 2019 20:30:00 +0100Application of semi-analytic method to compute the moments for solution of logistic model
http://msj.iau-arak.ac.ir/article_666926_0.html
The population growth, is increase in the number of individuals in population and it depends on some random environment eﬀects. There are several diﬀerent mathematical models for population growth. These models are suitable tool to predict future population growth. One of these models is logistic model. In this paper, by using Feynman-Kac formula, the Adomian decomposition method is applied to compute the moments for the solution of logistic stochastic diﬀerential equation.Wed, 07 Aug 2019 19:30:00 +0100On fuzzy wave equation based on generalized Hukuhara differentiability
http://msj.iau-arak.ac.ir/article_666927_0.html
In this paper, analytical fuzzy solutions for a fuzzy one-dimensional homogeneous and non-homogeneous wave equation are investigated and the new fuzzy solutions for these equations based on the type of generalized Hukuhara differentiability are presented. The existence and the uniqueness of the solutions, and the stability of the Cauchy problems are shown. In this scheme, a fuzzy wave equation can be solved without converting it to two crisp equations. Different types ofexamples are employed to show the effectiveness and efficiency of the approach.Wed, 07 Aug 2019 19:30:00 +0100