Theory of Approximation and Applications
Volume:15 Issue: 2, Summer and Autumn 2021

In this paper, we introduce the concept strong algebrability of certain C^* algebras generated by finite generators. In fact, using Gelfand theorem, we identify the members of the C^* algebra generated by one element, with the continuous functions on its spectrum, and use some recent result for strong algebrability for functions spaces.
Moreover, we introduce the new concept unitable elements in unital C^* algebras, and then we express our main result for this kind of elements. In fact, the C^* subalgebra generated by a non unitable element in a C^* algebra is strongly c algebrable.
As the last result in this paper, we show 2^c strong algebrability of direct sums of C^* algebras, using non unitable elements of them

The term green supply chain management mainly refers to those concepts which integrate the sustainable environmental processes into the outmoded supply chain. This process can include product design, manufacturing, production, material sourcing, and end of life management. According to this definition, GSCM1refers to a wide range of products from product design by recycling or destroy. In this process, the products are passed through a cycle of life. For example, as same as human beings, they also pass through the cycle of life such as birth, maturity, and death. The product life cycle involves a degree of structure to the life of products, which provide the directions for the functional efforts to produce and deliver the product. The main question in this research is “what are the effective factors in the implementation of the green supply chaining of construction projects and what are their priorities?” In this study will define key internal operational influences influencing the management of the Green Supply Chain through an analysis of its literature and a compilation of expert opinions. In this paper, the network analysis process method was used to prioritize the factors affecting the green supply chain in the UAE. The results showed that external factors, binding factors, internal factors and management factors affect the promotion of green supply chain system, respectively. And can have a positive impact on pollution reduction, economic development, social development, quality development and social capital.

Traditional data envelopment analysis (DEA) models evaluate the performance of decision-making units (DMUs) with the exact data and do not assume evaluation in the condition that the environment is uncertain. When some data are unknown, such as interval data, the DEA model is called imprecise DEA (IDEA). In this paper, we develop a new Malmquist productivity index(MPI) for dealing with interval data in DEA. Then, an approach for measuring the Malmquist productivity index using revenue efficiency is extended, too. The capabilities of the presented approach are shown by means of an example.

The present study seeks to investigate the impact of environmental friendly consumers' attitude on green brand intention. Based on literature review and identified gaps the study proposed an integrated theoretical model. To empirically test the proposed model this study collected data from 384 individual customers of questionnaire survey method. The study utilized Structural Equation Modeling (SEM) technique to statistically analyses measurement and structural models. The results show the positive effect of variables (environmental concern, attitude to environment, green brand quality and empirical satisfaction on green brand) on green purchase intention and negative impact of variable (environmental knowledge) on green purchase intention is.

Many real problems may often be reduced to solving a system of linear equations. However, in such real-world problems, the existence of uncertainties, like a fuzzy environment, is inevitable. Thus, the main aim of this paper is to propose a solving approach for a fuzzy linear system of equalities. The presented approach is based on the nearest weighted approximation of fuzzy numbers. Two numerical examples illustrate the capabilities of the proposed approach.

In this paper we extend fuzzy analytic hierarchy process into neutrosophic cubic environment. The neutrosophic cubic analytic hierarchy process can be used to manage more complex problems when the decision makers has a number of uncertainty, assigning preferences values to the considered object. We also define the concept of triangular neutrosophic cubic numbers and their operations laws. The advantages of the proposed methodology and the application of neutrosophic cubic analytic hierarchy process in decision making are shown by testing the numerical example in practical life.

In this paper, we consider Nearest points" and Farthest points" in normed linear spaces. For normed space (X; ∥:∥), the set W subset X, we dene Pg; Fg;Rg where g 2 W. We obtion results about on Pg; Fg;Rg. We nd new results on Chebyshev centers in normed spaces. In nally we dene remotal center in normed spaces.

In this work, we introduce a novel method for solving two-dimensional fuzzy Fredholm integral equations of the second kind (2D-FFIE-2). We use new representation of parametric form of fuzzy numbers and convert a two-dimensional fuzzy Fredholm integral equation to system of two-dimensional Fredholm integral equations of the second kind in crisp case. We can use Adomian decomposition method for nding the approximation solution of the each equation, hence obtain an approximation for fuzzy solution of 2D-FFIE-2. We prove the convergence of the method and nally apply the method to some examples

Honeycomb networks are built recursively using hexagonal tessellations. Wireless networks such as satellite networks, radio networks, sensor networks, cellular networks, ad hoc networks and other mobile network where honeycomb networks is used extensively. In this paper we study upper bound for restrained double Roman domination number for honeycomb networks.

In today's industrial and competitive world, the optimal use of time, resources, and timely and correct response to market needs are crucial. On the other hand, the importance and necessity of optimizing production based on market demand will reveal the need to manage high-value-added products. Regarding this fact that the steel industry is one of the basic industries and has a great influence upon the other industries, its productivity can affect itself as well as the other industries. The scope of this study is Isfahan Steel Corporation which is considered as one of the greatest plants throughout the country manufacturing steel products such as iron beams. Thus in this study, the corresponding documents and proofs were examined to optimize the beam products of Isfahan Steel Corporation based upon the market demand and increased value, and considering the records, opinions of production and sale experts, customers, and suppliers, a questionnaire was prepared to estimate the types of beam and distributed among customers and suppliers and analyzed. Then, the added value of beams was calculated and finally, the number of beam products was calculated based on estimated market demand using the model ARIMA.

This paper, introduces the fuzzy poisson process that plays an important role in the fuzzy sets and systems; specially, The spatial Poisson point process features prominently in spatial statistics, stochastic geometry, and continuum percolation theory. This point process is applied
in various physical sciences such as a model developed for alpha particles being detected. In recent years, it has been frequently used to model seemingly disordered spatial configurations of certain wireless communication networks.
For example, models for cellular or mobile phone networks have been developed where it is assumed the phone network transmitters, known as base stations, are positioned according to a homogeneous Poisson point process.

We suggest a new viscosity iterative scheme for finding a common element of the set of solutions of the general equilibrium problem system (GEPS) and the set of all common fixed points of two non-commutative non-expansive self mappings in the framework of a real Hilbert space. The results in the paper generalize and improve some well-known results in Jankaew et al.[2] and many others. Moreover, we present a numerical example (by using Maple software) to grantee the main result of this paper.