فهرست مطالب

Journal of Mathematical Extension
Volume:17 Issue: 8, Aug 2023

  • تاریخ انتشار: 1402/09/02
  • تعداد عناوین: 6
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  • Mona Gholamnia Taleshani, Mozhgan Taghidoost Laskukalayeh, Ahmad Abbasi Page 1

    In this paper we decompose Γα(Z(Zp1p2...pα)), a graph withvertises Z(Zp1p2...pα) and two distinct vertices x and y are adjacent ifand only if there exists i, 1 ≤ i ≤ α, such that pi | x, y. We obtaindimension, edge metric dimension, strong metric dimension, and fractionalmetric dimension for it.

    Keywords: 05C12, 05C51, 05C75, 05C90
  • Mohammad Javad Mehdipour *, Narjes Salkhordeh Page 2

    Let $A$ be an algebra with a right identity. In this paper, we study $(p, q)-$centralizers of $A$ and show that every $(p, q)-$centralizer of $A$ is a two-sided centralizer. In the case where, $A$ is normed algebra, we also prove that $(p, q)-$centralizers of $A$ are bounded. Then, we apply the results for some group algebras and verify that $L^1(G)$ has a nonzero weakly compact $(p, q)-$centralizer if and only if $G$ is compact and the center of $L^1(G)$ is non-zero. Finally, we investigate $(p, q)-$Jordan centralizers

    Keywords: (p, q)−centralizers, q)−Jordan centralizers, algebras
  • Mostafa Hassanlou *, Ebrahim Abbasi Page 3

    In this paper, we investigate weighted composition, Volterra and Integral operators on second derivative Hardy spaces. Some equivalent conditions for boundedness of the operators will be given using the  boundedness on the Hardy spaces. Also we give a criteria for compactness of weighted composition operators.

    Keywords: derivative Hardy spaces, bounded operator, compact operator, weighted composition operators
  • Mehrnoosh Shadravan, Rajab Ali Borzooei Page 4

    The domatic number d(G) of a graph G is the maximum k for which V (G) can be partitioned into k pairwise disjoint dominating sets. In this paper, we determine the domatic numbers of complete graphs, complete k-partite graphs, Johnson graphs J(n, 2), unicyclic graphs, bicyclic graphs and generalized Θ-graphs.

    Keywords: Domatic number, vertex coloring, couponcoloring
  • Zahra Dehvari, MohammadSadegh Modarres Mosaddegh Page 5

    In this article, we dene quasi-normed quasilinear spaces and show that the space of all bounded quasilinear q-operators on this space is an Ù-space. Due to the importance of the problem of stability of functional equations in different spaces, many authors have studied the stability of functional equations in different spaces. Tabor proved the stability of the Cauchy functional equation in quasi-Banach spaces. We prove the stability of functional equations in quasi-normed quasilinear spaces

    Keywords: Quasilinear spaces, Quasilinear q-operators, Quasi-normed quasilinear spaces, Stability of functional equations
  • Mahsa Nasiri, Mohsen Rostamy-Malkhalifeh, Hadi Bagherzadeh valami Page 6

    In recent years, the environmental issue has attracted widespread concern from the international 6 community, as gas waste, water waste, and solid wastes generated in the production process of factories. 7 Recent studies on environmental management have forced commercial organizations to re-evaluate 8 their roles and responsibilities for protecting the natural environment. This study focuses on the DEA 9 environmental assessment via the concept of congestion. Recognizing the congestion of units is one of 10 the most attractive issues in the literature of Data Envelopment Analysis (DEA), because the decision 11 maker (DM) can use this concept to decide whether to increase or decrease the size of a Decision12 Making Unit (DMU). In the DEA literature, congestion is classified into Undesirable Congestion (UC) 13 and Desirable Congestion (DC). In many real-world situations, we cannot determine the exact value for 14 all data, hence, some parameters are inevitably reported as uncertain data, e.g. stochastic data, fuzzy 15 data, interval data and so on. This study focuses on considering Returns to Damage (RTD) under UC 16 and Damages to Return (DTR) under DC in the situation that the input and desirable and undesirable 17 outputs are reported as interval data. For this purpose, some uncertain models under the different 18 production possibility sets (PPS) are formulated and then we use the robust optimization technique to 19 formulate the equivalent certain models. The potential of the proposed methods is illustrated by a 20 numerical example.

    Keywords: Data Envelopment Analysis, Returns to Damage, Damages to Return, Undesirable22 Congestion, Desirable Congestion