Caspian Journal of Mathematical Sciences (CJMS)Caspian Journal of Mathematical Sciences (CJMS)
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Feed provided by Caspian Journal of Mathematical Sciences (CJMS). Click to visit.Category of $H$-groups
http://cjms.journals.umz.ac.ir/article_2253_498.html
‎This paper develops a basic theory of $H$-groups‎. ‎We‎ ‎introduce a special quotient of $H$-groups and‎ ‎extend some algebraic constructions of topological groups to the category‎ ‎of H-groups and H-maps and then present a functor from this category to the category of quasitopological groups‎.Tue, 31 Dec 2019 20:30:00 +0100Multi-step conformable fractional differential transform method for solving and stability of ...
http://cjms.journals.umz.ac.ir/article_1893_0.html
‎In this article‎, ‎the multi-step conformable fractional differential transform method (MSCDTM) is applied to give approximate solutions of the conformable fractional-order differential systems‎. ‎Moreover‎, ‎we check the stability of conformable fractional-order L"{u} system with the MSCDTM to demonstrate the efficiency and effectiveness of the proposed procedure.Sat, 11 Aug 2018 19:30:00 +0100Weighted composition operators on weighted Bergman spaces and weighted Bloch spaces
http://cjms.journals.umz.ac.ir/article_2479_498.html
In this paper, we characterize the bonudedness and compactness of weighted composition operators from weighted Bergman spaces to weighted Bloch spaces. Also, we investigate weighted composition operators on weighted Bergman spaces and extend the obtained results in the unit ball of $mathbb{C}^n$.Tue, 31 Dec 2019 20:30:00 +0100Heat and mass transfer analysis on MHD peristaltic motion of solid particles in a dusty fluid
http://cjms.journals.umz.ac.ir/article_1895_0.html
In this article, effects of heat and mass transfer on MHD peristaltic motion of solid particles in a dusty fluid has been investigated. The effects of nonlinear thermal radiation and Hall Effect are also taken into account. The relevant flow analysis is modelled for fluid phase and dust phase in wave frame. Computation of solutions is presented for velocity profile, temperature profile and concentration profile. The impact of all the physical parameters such as particle volume fraction, Hartmann number, Hall Effect, Prandtl number, Eckert number, Schmidt number and Soret number are discussed mathematically and graphically. It is noted that the influence of magnetic field and particle volume fraction opposes the flow. Also, the impact of particle volume fraction is quite opposite on temperature and concentration profile.Sat, 11 Aug 2018 19:30:00 +0100A new idea for exact solving of the complex interval linear systems
http://cjms.journals.umz.ac.ir/article_2324_498.html
In this paper‎, ‎the aim is to find a complex interval vector [Z] such that satisfies the complex interval linear system C[Z]=[W]‎. ‎For this‎, ‎we present a new method by restricting the general solution set via applying some parameters‎. ‎The numerical examples are given to show ability and reliability of the proposed method.Tue, 31 Dec 2019 20:30:00 +0100Curves and helix hypersurfaces in Euclidean spaces
http://cjms.journals.umz.ac.ir/article_1898_0.html
In this paper, we investigate the special curves and the ruled surfaces on the helix hypersurface whose tangent space makes constant angle with a fixed direction in Euclidean -space and give requirement of being developable of the ruled surfaces. Also, we construct the helix surface generated by a plane curve in Euclidean 3-space and give requirement of being a minimal surface of the surface.Sat, 11 Aug 2018 19:30:00 +0100Translation surfaces according to a new frame
http://cjms.journals.umz.ac.ir/article_2480_498.html
In this paper we studied the translation surfaces according to a new frame called q-frame in three dimensional Euclidean space. The curvatures of the translation surface are obtained in terms of q-frame curvatures. Finally some special cases are investigated for these surfaces.Tue, 31 Dec 2019 20:30:00 +0100The Generalized difference of $d \left(\chi^{3\textit{I}}\right)$ of fuzzy real numbers over ...
http://cjms.journals.umz.ac.ir/article_1902_0.html
In this article we introduce the sequence spaces $left[chi^{3q}_{fmu },left|left(dleft(x_{1}right),dleft(x_{2}right),cdots, dleft(x_{n-1}right)right)right|_{p}right]^{textit{I}left(Fright)}$ and $left[Lambda^{3q}_{fmu },left|left(dleft(x_{1}right),dleft(x_{2}right),cdots, dleft(x_{n-1}right)right)right|_{p}right]^{textit{I}left(Fright)},$ associated with the differential operator of sequence space defined by Musielak. We study some basic topological and algebraic properties of these spaces. We also investigate some inclusion relations related to these spaces.Sun, 12 Aug 2018 19:30:00 +0100Mathematical modeling of dynamics behavior of terrorism and control
http://cjms.journals.umz.ac.ir/article_2476_498.html
Terrorism is generally understood to be the use of threat or extra normal violence to gain ideological reasons and personal benefit. In this paper, a mathematical modelling of terrorism with military strategies and rehabilitation of terrorists was constructed. The model is developed to control the spread of terrorist ideologies in the society and suitable to describe terrorist group. The population is divided into six compartments: $S(t)$, $I(t)$, $T(t)$, $T_L(t)$, $T_S(t)$ and $Q_T(t)$. Furthermore, the basic reproduction number, $R_0$ is also calculated if $R_0 < 1$ means the terror-organization is nearly eradicated and if $R_0 > 1$ means the number of terrorists are high where the terrorist are endemic to the population. The result of the sensitivity analysis shows that the most sensitive parameters is the recruitment pool of the terrorist from susceptible to moderate $(beta_{1})$ and terrorist move to detention facilities due to counter-terrorist activities $(b)$. The least parameter is the probability at which terrorist become militancy leaders $(kalpha)$. $(beta_{1})$ and $(b)$ are parameters counter terrorist need to be target. The finding shows that the military/dialogue strategies are to be used while military strategies alone should not be used if the number of terrorists is below a certain reproduction numberTue, 31 Dec 2019 20:30:00 +0100An approach for designing a developable surface through a sweeping surface
http://cjms.journals.umz.ac.ir/article_2277_0.html
This paper studies the problem to construct a developable surface through a sweeping surface, using a special orthonormal frame of the spine curve, namely the (so--called) rotation minimizing frame (RMF for short). As a result, the necessary and sufficient condition for the sweeping surface to be a developable ruled surface is derived. In particular, we mainly focus on the study for the resulting developable surface to be cylinder, cone or tangent surface. Finally, we give some representative examples.Sun, 25 Aug 2019 19:30:00 +0100Normal Fermi-Walker Derivative in $E_{1}^{3}$
http://cjms.journals.umz.ac.ir/article_2490_498.html
In this paper, firstly, in $E_1^3$, we defined normal Fermi-Walker derivative and applied for the adapted frame. Normal Fermi-Walker parallelism, normal non-rotating frame, and Darboux vector expressions of normal Fermi-Walker derivative by normal Fermi-Walker derivative are given for adapted frame. Being conditions of normal Fermi-Walker derivative and normal non-rotating frame are examined for frames throughout spacelike, timelike, lightlike curves. It is shown that the vector field which takes part in [17] is normal Fermi-Walker parallel by the normal Fermi-Walker derivative throughout the spacelike, timelike, and lightlike general helix. Also, we show that the Frenet frame is a normal non-rotating frame using the normal Fermi-Walker derivative. Afterward, we testified that the adapted frame is a normal non-rotating frame throughout the spacelike, timelike, and lightlike general helix.Tue, 31 Dec 2019 20:30:00 +0100SCHWARZ BOUNDARY VALUE PROBLEM ON A TRIANGLE
http://cjms.journals.umz.ac.ir/article_2339_0.html
In this paper, the Schwarz boundary value problem (BVP) for the inhomogeneous Cauchy-Riemann equation in a triangle is investigated explicitly. Firstly, by the technique of parquetingreflection and the Cauchy-Pompeiu representation formula a modified Cauchy-Schwarz representation formula is obtained. Then, the solution of the Schwarz BVP is explicitly solved. In particular, the boundary behaviors at the corner points are considered.Wed, 13 Nov 2019 20:30:00 +0100Weighted composition operators between Lipschitz algebras of complex-valued bounded functions
http://cjms.journals.umz.ac.ir/article_2337_498.html
‎In this paper‎, ‎we study weighted composition operators between Lipschitz algebras of complex-valued bounded functions on metric spaces‎, ‎not necessarily compact‎. ‎We give necessary and sufficient conditions for the injectivity and the surjectivity of these operators‎. ‎We also obtain sufficient and necessary conditions for a weighted composition operator between these spaces to be compact.Tue, 31 Dec 2019 20:30:00 +0100Application of legendre operational matrix to solution of two dimensional nonlinear volterra ...
http://cjms.journals.umz.ac.ir/article_2363_0.html
In this article, we apply the operational matrix to find the numerical solution of two- dimensional nonlinear Volterra integro-differential equation (2DNVIDE). Form this prospect, two-dimensional shifted Legendre functions (2DSLFs) has been presented for integration, product as well as differentiation. This method converts 2DNVIDE to an algebraic system of equations, so the numerical solution of 2DNVIDE is computable. The effectiveness and accuracy of the method were examined with some examples as well. The results and comparison with other methods have shown a remarkable performance.Sun, 24 Nov 2019 20:30:00 +0100A Novel Successive Approximation Method for Solving a Class of Optimal Control Problems
http://cjms.journals.umz.ac.ir/article_2338_498.html
This paper presents a successive approximation method (SAM) for solving a large class of optimal control problems. The proposed analytical-approximate method, successively solves the Two-Point Boundary Value Problem (TPBVP), obtained from the Pontryagin's Maximum Principle (PMP). The convergence of this method is proved and a control design algorithm with low computational complexity is presented. Through the finite number of algorithm iterations, a suboptimal control law is obtained for the optimal control problem. An illustrative example is given to demonstrate the efficiency of the proposed method.Tue, 31 Dec 2019 20:30:00 +0100INVERSE SCATTERING PROBLEM FOR THE ·IMPULSIVE SCHRÖDINGER EQUATION WITH A POLYNOMIAL SPECTRAL ...
http://cjms.journals.umz.ac.ir/article_2378_0.html
In the present work, under some di¤erentiability conditions on the potential functions , we rst reduce the inverse scattering problem (ISP) for the polynomial pencil of the Scroedinger equation to the corresponding ISP for the generalized matrix Scrödinger equation . Then ISP will be solved in analogy of the Marchenko method. We aim to establish an e¤ective algorithm for uniquely reconstructing of the potential functions of the equation in that case when there is no a discrete spectrumMon, 02 Dec 2019 20:30:00 +0100Weighted slant Toep-Hank Operators
http://cjms.journals.umz.ac.ir/article_2478_498.html
A $it{weighted~slant~Toep}$-$it{Hank}$ operator $L_{phi}^{beta}$ with symbol $phiin L^{infty}(beta)$ is an operator on $L^2(beta)$ whose representing matrix consists of all even (odd) columns from a weighted slant Hankel (slant weighted Toeplitz) matrix, $beta={beta_n}_{nin mathbb{Z}}$ be a sequence of positive numbers with $beta_0=1$. A matrix characterization for an operator to be $it{weighted~slant~Toep}$-$it{Hank}$ operator is also obtained.Tue, 31 Dec 2019 20:30:00 +0100Berezin number inequalities involving superquadratic functions
http://cjms.journals.umz.ac.ir/article_2379_0.html
We consider superquadratic functions f and define selfadjoint operators f(A) from some selfadjoint operators A on a reproducing kernel Hilbert space H=H(Q). We estimate the so-called Berezin number of operator f(A).Mon, 02 Dec 2019 20:30:00 +0100Starlike Functions of order $\alpha$ With Respect To $2(j,k)$-Symmetric Conjugate Points
http://cjms.journals.umz.ac.ir/article_2323_498.html
In this paper, we introduced and investigated starlike and convex functions of order α with respect to 2(j,k)-symmetric conjugate points and coefficient inequality for function belonging to these classes are provided . Also we obtain some convolution condition for functions belonging to this class.Tue, 31 Dec 2019 20:30:00 +0100Existence results for hybrid fractional differential equations with Hilfer fractional derivative
http://cjms.journals.umz.ac.ir/article_2420_0.html
This paper investigates the solvability, existence and uniqueness of solutions for a class of nonlinear fractional hybrid differential equations with Hilfer fractional derivative in a weighted normed space. The main result is proved by means of a fixed point theorem due to Dhage. An example to illustrate the results is included.Mon, 16 Dec 2019 20:30:00 +0100Group analysis of time-fractional equation with Riemann-Liouville derivative
http://cjms.journals.umz.ac.ir/article_2425_0.html
Finding Lie symmetries of nonlinear fractional differential equations plays an important role in studying fractional differential equations. The purpose of this manuscript is to find the Lie point symmetries of the time-fractional Buckmaster equation. After that we use the innitesimal generators for obtaining their corresponding invariant solutions.Sun, 22 Dec 2019 20:30:00 +0100Solving fuzzy multi objective liner programming problems: an α-cut approach
http://cjms.journals.umz.ac.ir/article_2437_0.html
In this paper, as an extension of Pareto optimality concepts for multi objective programming problems to fuzzy multi objective linear programming (FMOLP) problems, different types of Pareto optimal solutions (POSs), namely, weakly, strictly, and properly POSs are defined on the basis of α-cuts of fuzzy numbers. Then a method for solving FMOLP problems is proposed to obtain them. It is shown that they can be obtained by solving some non fuzzy multi objective linear programming problems. A numerical example is solved to illustrate the method.Mon, 06 Jan 2020 20:30:00 +0100Some results on Hermite-Hadamard type inequalities with respect to fractional integrals
http://cjms.journals.umz.ac.ir/article_2471_0.html
In this paper, we establish Hermite-Hadamard type inequalities for uniformly p-convex functions. Also, a new fractional Hermite-Hadamard type inequality for convex functions is obtained by using only the left Riemann-Liouville fractional integral. Finally some extimation of left fractional integration studies for Hermite- Hadamard type inequalities.Sun, 12 Jan 2020 20:30:00 +0100Non-trivial solutions for a discrete nonlinear boundary value problem with $\phi_c$-Laplacian
http://cjms.journals.umz.ac.ir/article_2472_0.html
In this paper, we prove the existence of at least one non-trivial solution for a discrete nonlinear boundary value problem with $phi_c$-Laplacian. The approach is based on variational methods.Tue, 14 Jan 2020 20:30:00 +0100On the D-concircular curvature tensor of a generalized Sasakian-Space-form
http://cjms.journals.umz.ac.ir/article_2515_0.html
The object of this paper is to study of D-concircular curvature tensor on generalized Sasakian-space-forms. Actually we consider generalized Sasakian-space-forms when it is, respectively: D-concircularly flat; D-concircular-pseudosymmetric; D-concircularly Ricci-semisymmetric; D-concircularly symmetric; $V (xi;X) .R = 0$. Most of the main results obtained in this paper are in the form of necessary and sufficient conditions.Tue, 31 Dec 2019 20:30:00 +0100Some Results on Soft Hypervector Spaces
http://cjms.journals.umz.ac.ir/article_2516_0.html
In this paper, some basic properties of soft hypervector spaces are studied with respect to some well-known operations such as intersection, union, AND, OR, product and sum. Also, the behavior of them is investigated under linear transformations and b-linear transformations.Sun, 16 Feb 2020 20:30:00 +0100Bayesian two-sample prediction problem for the Rayleigh distribution under progressively ...
http://cjms.journals.umz.ac.ir/article_2542_0.html
‎In this paper‎, ‎we study the ‎prediction problem in the two-sample case for predicting future progressively Type-II censored order statistics based on observed progressively Type-II censored order statistics with random removals from the Rayleigh distribution‎. ‎We consider two important distributions for random removals‎, binomial and discrete uniform distributions‎. ‎In both cases‎, ‎Bayesian point and interval predictors are obtained‎. ‎In the following‎, ‎through a simulation study‎, ‎the results are compared to each other‎. ‎Finally‎, ‎a real data set is given to textcolor{red}{illustrate} the output results‎.Sat, 14 Mar 2020 20:30:00 +0100COHOMOLOGY OF aff(1|1) ACTING ON THE SPACE OF BILINEAR DIFFERENTIAL OPERATORS ON THE SUPERSPACE R1|1
http://cjms.journals.umz.ac.ir/article_2545_0.html
We consider the aff(1)-module structure on the spaces of bilinear diﬀerential operators acting on the spaces of weighted densities. We compute the ﬁrst diﬀerential cohomology of the Lie superalgebra aff(1) with coeﬃcients in space Dλ,ν;µ of bilinear diﬀerential operators acting on weighted densities. We study also the super analogue of this problem getting the same results.Fri, 03 Apr 2020 19:30:00 +0100Solving Defender-Attacker Game with Multiple Decision Makers Using Expected-Value Model
http://cjms.journals.umz.ac.ir/article_2546_0.html
Defender-attacker game is a model for conflicting between a defender and an attacker. Defender tries to prevent attacking an opponent by assigning limited security resources. In real world the utility values of the defender-attacker game are assigned by experts which usually are uncertain. According to that the assigned values by several experts may be slightly different and conflicting, we consider a set of all their viewpoints. This approach is similar to hesitant fuzzy environment. Also, each of the experts may have the different weights; AHP method is used to determine the weights of each of the experts. A weighted sum method is applied to obtain a game with aggregated payoffs. An expected value of the fuzzy numbers is introduced to convert the problem into defender-attacker game with interval payoffs. According to this, we proposed a method to solve security game in fuzzy environment. It is shown that the optimal solution of the expected value model is the optimal solution of the original model. Finally, a practical example is illustrated to solve by the proposed method.Fri, 03 Apr 2020 19:30:00 +0100Some geometrical properties of the Oscillator group
http://cjms.journals.umz.ac.ir/article_2577_0.html
‎We consider the oscillator group equipped with‎ ‎a biinvariant Lorentzian metric‎. ‎Some geometrical properties of this space and the harmonicity properties of left-invariant vector fields on this space are determined‎. ‎In some cases‎, ‎all these vector fields are critical points for the energy functional‎ ‎restricted to vector fields‎. ‎Left-invariant vector fields defining harmonic maps are also classified‎, ‎and the energy of these vector‎ ‎fields is explicitly calculat‎e‎d.Sat, 02 May 2020 19:30:00 +0100A Meshless Method for Numerical Solutions of Non-Homogeneous Differential Equation with ...
http://cjms.journals.umz.ac.ir/article_2578_0.html
This paper is devoted to solve a class of differential equation with simultaneously combining variable coeffcients and variable delays namely variable-delay dierential equations (VDDEs). For this purpose, a numerical method is proposed in which the unknown function and its derivative are approximated with the basis of interpolating Multiquadric radial basis functions (MQRBFs) at arbitrary collocation points. According to the existing mechanism, the synchronization problem is recast to a system of algebraic equations. In the other hand, the proposed method provides a very adjustable framework for approximation according to the discretization and due to a board range of arbitrary nodes. Finally, some illustrative examples are given to verify the validity and applicability of the new technique and also a comparison between our results and the existing studies is performed.Sat, 02 May 2020 19:30:00 +0100A numerical method for solving singularly perturbed differential-difference equation arising in ...
http://cjms.journals.umz.ac.ir/article_2587_0.html
In this paper, an efficient procedure based on the multiquadric radial basis functions (RBFs) collocation method is applied for the numerical so- lution of the singularly perturbed differential-difference (SPDDE) equation. The method is coupled with the Residual subsampling algorithm for sup- port adaptivity. The problem considered in this paper shows turning point behavior which is added to the complexity in the construction of numerical approximation to the solution of the problem. The proposed algorithm is very simple to perform. Some numerical examples are given to validate the computational efficacy of the suggested numerical scheme.Wed, 13 May 2020 19:30:00 +0100F -Sums of Graphs and their Reformulated-Zagreb Indices
http://cjms.journals.umz.ac.ir/article_2588_0.html
The reformulated Zagreb index EM1(G) of a simple graph G is defined as the sum of the terms (du + dv − 2)2 over all edges uv of G. In this paper, we study the reformulated Zagreb indices for the F -sums of some special well-known graphs such as subdivision and total graph which is introduced by Eliasi and Taeri [2].Thu, 14 May 2020 19:30:00 +0100Liapounoff's type numbers for a homogeneous linear system of fractional order
http://cjms.journals.umz.ac.ir/article_2655_0.html
In this paper, first we consider a homogeneous linear system of fractional order 0<alpha leq 1. Next, Liapounoff's type numbers of solutions of this system is proposed. Also, the previous results are a special case of our results.Sun, 07 Jun 2020 19:30:00 +0100coretractable modules relative to delta
http://cjms.journals.umz.ac.ir/article_2714_0.html
Let R be a ring and M a right R-module. We call M, a delta(M)-coretractable module if for every proper submodule N of M containing delta(M), there is a nonzero homomorphism from M=N to M. We investigate some conditions which under two concepts delta(M)-coretractable and coretractable coincide. For a ring R, we prove that R is right Kasch if and only if R_R is delta(R-R)-coretractable.Mon, 06 Jul 2020 19:30:00 +0100GOLDEN NUMBERS
http://cjms.journals.umz.ac.ir/article_2715_0.html
‎The golden ratio $phi=frac{1+sqrt{5}}{2}=1/61803398874...$ is the root of the polynomial $x^2-x-1=0$‎, ‎and is the one of the important numbers in mathematics‎. ‎The golden ratio is also used in many fields of science‎. ‎The golden ratio appears in some patterns in nature‎, ‎including the spiral arrangement of leaves and other plant parts‎. ‎In this paper‎, ‎we present a sequence of golden numbers ${phi_n}_n$ and study their properties‎.Mon, 06 Jul 2020 19:30:00 +0100One Dimensional Dirac Operators on Time Scales
http://cjms.journals.umz.ac.ir/article_2721_0.html
In this work, we study some spectral properties of one dimensional Dirac system, such as formally self-adjointness, orthogonality of eigenfunctions, Green's function, existence of a countable sequence of eigenvalues. Later, we give an expansion formula in eigenfunctions for Dirac operator on time scales. These results will provide an important contribution to the spectral theory of such operators on time scales.Fri, 10 Jul 2020 19:30:00 +0100The converse of Baer's theorem for two-nilpotent variety
http://cjms.journals.umz.ac.ir/article_2732_0.html
In this paper the generalization of the converse of Baer's theorem for two-nilpotent variety of class row $(n,m)$. is carried out. Baer proved that finiteness of $G/Z_n(G)$ implies that $gamma_{n+1}(G)$ is finite. Hekster proved the converse of the Baer's theorem with the assumption that $G$ can be finitely generated. The Baer's theorem can be considered as a result of a classical theorem by Schur denoting that finiteness of $G/Z(G)$ leads to the finiteness of $G'$. The converse of the Baer's theorem has been proved conditionally by Taghavi et al. (2019), as well. In the Main Theorem, we prove that, if $gamma_{m,n}(G)cap Z_{n,m}(G)=1$ and $gamma_{m,n+i}(G)$ is finite for some $n,i,m geq 0$. Then $G/Z_{n,m}(G)$ is finite. In this article some other results are attained by the converse of the Baer's theorem. It is also concluded that when $n=m=1$. Similar results are obtained for variety of the soluble groups. In addition, the converse of the Schur's theorem which proved by Halasi and Podoski is concluded in this paper, for two-nilpotent variety. We have also obtained some similar results of Chakaneh et al. (2019) for $(n,m)$-isoclinic family of groups and $(1,m)$-stem groups.Fri, 17 Jul 2020 19:30:00 +0100Stability of Sacks-Uhlenbeck Biharmonic Maps
http://cjms.journals.umz.ac.ir/article_2751_0.html
In this paper, the first and second variation formulas of the Sacks-Uhlenbeck bienergy functional is obtained. As an application, instability and non-existence theorems for Sacks-Uhlenbeck biharmonic maps are given.Mon, 20 Jul 2020 19:30:00 +0100An introduction to topological hyperrings
http://cjms.journals.umz.ac.ir/article_2752_0.html
In this paper, we define topological hyperrings and study their basic concepts which supported by illustrative examples. We show some differences between topological rings and topological hyperrings. Also, by the fundamental relation $Gamma^{*}$, we indicate the role of complete parts (saturated subsets) and complete hyperrings in topological hyperrings and specially we show that if every (closed) open subset is a complete part in a topological complete hyperring then its fundamental ring is a topological ring. Finally, we study the quotient topology induced by $Gamma^{*}$-relation on an associated Krasner hyperring obtained by a ring and show that it is isomorphic to a quotient space of the ring by its ideals.Tue, 21 Jul 2020 19:30:00 +0100Construction of Closure Operations in a Category of Presheaves
http://cjms.journals.umz.ac.ir/article_2782_0.html
We construct some types of universal closure operations induced by certain collection of morphisms. For this purpose, we use Lawvere-Tierney topologies and universal closure operations that correspond to each other to establish the equivalent conditions over the collection of morphisms. In this way we use multiple sieves instead of principal sieves for constructing results. Examples are also given to illustrate the established results.Tue, 04 Aug 2020 19:30:00 +0100$k$-distance enclaveless number of a graph
http://cjms.journals.umz.ac.ir/article_2783_0.html
For an integer $kgeq1$, a $k$-distance enclaveless number (or $k$-distance $B$-differential) of a connected graph $G=(V,E)$ is $Psi^k(G)=max{|(V-X)cap N_{k,G}(X)|:Xsubseteq V}$. In this paper, we establish upper bounds on the $k$-distance enclaveless number of a graph in terms of its diameter, radius and girth. Also, we prove that for connected graphs $G$ and $H$ with orders $n$ and $m$ respectively, $Psi^k(Gtimes H)leq mn-n-m+Psi^k(G)+Psi^k(H)+1$, where $Gtimes H$ denotes the direct product of $G$ and $H$. In the end of this paper, we show that the $k$-distance enclaveless number $Psi^k(T)$ of a tree $T$ on $ngeq k+1$ vertices and with $n_1$ leaves satisfies inequality $Psi^k(T)leqfrac{k(2n-2+n_1)}{2k+1}$ and we characterize the extremal trees.Tue, 04 Aug 2020 19:30:00 +0100A note on some parameters of domination on the edge neighborhood graph of a graph
http://cjms.journals.umz.ac.ir/article_2784_0.html
The edge neighborhood graph N_{e}(G) of a simple graph G is the graph with the vertex set E ∪ S where S is the set of all open edge neighborhood sets of G and two vertices u,v ∈ V (N_e{}(G)) adjacent if u ∈ E and v is an open edge neighborhood set containing u. In this paper, we determine the domination number, the total domination number, the independent domination number and the 2-domination number in the edge neighborhood graph. We also obtain a 2-domination polynomial of the edge neighborhood graph for some certain graphs.Tue, 04 Aug 2020 19:30:00 +0100Inverse Connective Eccentricity Index and its Applications
http://cjms.journals.umz.ac.ir/article_2785_0.html
The inverse connective eccentricity index of a connected graph G is defined as ξ−1 ce (G) =P u∈V(G)ǫG(u)dG(u) , where ǫG(u) and dG(u) are the eccentricity and degree of a vertex u in G,respectively. In this paper, we obtain an upper bounds for inverse connective eccentricity indices for various classes of graphs such as generalized hierarchical product graph and F-sum of graphs.Tue, 04 Aug 2020 19:30:00 +0100On strongly PI-lifting modules
http://cjms.journals.umz.ac.ir/article_2801_0.html
In this paper, the class of strongly PI-lifting modules is introduced and investigated. The connections between strongly PI-lifting modules and the generalizations of lifting modules are presented. We provide that the class of strongly PI-lifting modules is contained in the class of PI-lifting modules. Moreover, it is proved that for an Abelian ring R, R is PI-lifting as a right R-module if and only if R=I has a projective cover for every right ideal I of R. The structural properties of strongly PI-lifting modules are determined, and examples are provided to exhibit and delimit our results.Tue, 11 Aug 2020 19:30:00 +0100Concerning strongly divisible, strongly fixed, and strongly $z$-ideals in $\mathcal{R}L$
http://cjms.journals.umz.ac.ir/article_2802_0.html
As usual, the ring of continuous real-valued functions on a frame $L$ is denoted by $mathcal{R}L$. We determine the relation among strongly $z$-ideals, strongly divisible ideals and uniformly closed ideals in the ring $mathcal{R}L$. We characterize Lindel"of frames based on strongly fixed ideals in $mathcal{R}L$. We observe that a weakly spatial frame $L$ is Lindel"of if and if every strongly divisible ideal in $mathcal{R}L$ is strongly fixed; if and only if every closed ideal in $mathcal{R}L$ is strongly fixed.Tue, 11 Aug 2020 19:30:00 +0100The induced contractive maps on the covering spaces
http://cjms.journals.umz.ac.ir/article_2812_0.html
‎ ‎Let $(tilde{X},p)$ be the universal covering space of a compact metrizable space $ X $‎, ‎which is compact and locally path connected‎. ‎In this paper‎, ‎we show that there exist metrics $ d $ and $ d' $ for $ X $ and $tilde{X} $‎, ‎respectively‎, ‎such that any contractive map ‎$ f:Xto X $ induces a contractive map on $ tilde{X}$. ‎As an‎ application‎, ‎it is obtained that every iterated function system(IFS) on the space $ X $ with attractor $ K $‎, ‎induces an IFS on $tilde{ X} $ with attractor $tilde{K},$ such that $ p(tilde{K})=K$‎.Wed, 19 Aug 2020 19:30:00 +0100Linear System of Equations with Doubly Stochastic Interval Coefficient Matrix
http://cjms.journals.umz.ac.ir/article_2813_0.html
‎In this paper‎, ‎we first give an overview of doubly stochastic interval matrices‎. ‎Then‎, ‎we present some theories about the interval linear system whose coefficient matrix is doubly stochastic interval matrix‎. ‎Also‎, ‎we give an outer estimation for the solution set of these systems‎.Wed, 19 Aug 2020 19:30:00 +0100N− Transvectants
http://cjms.journals.umz.ac.ir/article_2814_0.html
We consider the sl(2,R)-module structure on the spaces of n−ary diﬀerential operators acting on the spaces of weighted densities. We classify sl(2,R)-invariant n−ary diﬀerential operators acting on the spaces of weighted densities.Wed, 19 Aug 2020 19:30:00 +0100ON BI-IDEAL ELEMENTS IN POE-AG-GROUPOID
http://cjms.journals.umz.ac.ir/article_2819_0.html
In this paper we introduce the concept of ideal and bi-ideal elements in poe-AG-groupoid and give some characterizations and properties of their bi-ideal elements. So we consider some results concerning bi-ideals in poe-semigroups and investigate them in poe-AG-groupoids. Also, the class of bi-ideal elements of poe-AG-groupoids are studied, certain intrinsic and basic properties of poe-AG-groupoids including:∧-semilattice, bi-ideal, semiprime, weaklyprime, totallyorderedelements and etc. are studied as well. The corresponding results on poe-semigroups can be also obtained as application of the results of this paper.Mon, 24 Aug 2020 19:30:00 +0100