One of the key issues raised in networks flow is its interdiction. Keshavarzi et al. scrutinized the issue with the multi-sources and multi-sinks conditions in mind while considering the specific conditions of flow being sent from sources to sinks [R. Keshavarzi et al., Multi-source-sinks network flow interdiction problem, International Journal of Academic Research, 2015]. Moreover, the matter was also examined in the state of multi-interdictors and a practical solution was presented [Keshavarzi and, Salehi, Multi commodity multi source-sinks network flow interdiction problem with several interdictors, Journal of Engineering and Applied Sciences, 2015]. In this paper, the networks flow interdiction in multi-source and multi-sink conditions was addressed; meanwhile, bearing in mind the uncertain data (from a specified beginning to an ending interval), an optimal interval was presented. Finally, a numerical example for this issue was provided and then solved by the program Lingo.
In the present study the researchers believes that, risk of delays should be managed, minimized, shared, transferred or accepted, but it cannot be ignored. By providing an innovative method with the help of the Work breakdown Structure, Baseline, Hierarchical Technique and Data Envelopment Analysis (DEA), the researchers will control the risk of projects and even prevent them from occurring.
In this research paper, a numerical method is presented for solving second-order hybrid fuzzy differential equations by using fuzzy Taylor expansion under generalized Hukuhara differentiability and also with convergence theorem. Also, the method is illustrated by solving several numerical examples. The final results showed that the solution of the second-order hybrid fuzzy differential equations.
In this letter, the problem of determining heat transfer from convecting-radiating fin of rectangular shape is investigated. We consider steady conduction in the fin and neglect radiative exchange between adjacent fins and between the fin and its primary surface. It is demonstrated that the governing fin equation is exactly solvable. The exact, closed-form analytical solutions in implicit form are convenient for physical interpretation and optimization for maximum heat transfer.
Dynamical systems with delay are widespread in nature. The study of time-delay induced changes in the collective behavior of systems of coupled nonlinear oscillators is a subject of great interest, both because of its fundamental importance from the point of view of dynamical systems and because of its practical applications. In this paper, an explicit technique is proposed for numerical solution of nonlocal dynamical systems with time delay. The proposed method is adopted quadratic spline interpolation. Then, the error analysis of the developed method is discussed. It is exploited in the discussion of nonlocal delay Ikeda and Hutchinson models. Finally, the performance of the presented approach is verified by applying the error and convergence study for different values of fractional order parameters.
In this paper, the first, second and third Zagreb indices, the first and second multiplicative Zagreb indices, the F-index and F-polynomial of benzyl ether dendrimer with C60H core and benzyl ether dendrimer with porphyrin core are calculated. In addition, the first and second Zagreb coindices, the first and second multiplicative Zagreb coindices of these graphs are computed as well. Finally, the multiplicative Zagreb index of these graphs is computed through the link of graphs.
Micromixers are an important part of microfluidics systems. In the present work, mixing was enhanced through the three helix types of micromixers. As a result of Dean vortices, a mixing index of 99% obtained at a very short length of the micromixers for the Reynolds number of 10. It is also obtained that the micromixer with rectangular cross-section showed better enhancement compared to the circular and triangular cross-section.
The current study aims to establish a connection between graphs and automata theory, which apparently demonstrate different mathematical structures. Through searching out some properties of one of these structures, we try to find some new properties of the other structure as well. This will result in obtaining some unknown properties. At first, a novel automaton called zero-forcing (Z-F) finite automata is defined according to the notion of a zero-forcing set of a graph. It is shown that for a given graph and for some zero forcing sets, various Z-F-finite automata will be obtained. In addition, the language and the closure properties of Z-F-finite automata, in particular; union, connection, and serial connection are studied. Moreover, considering some properties of graphs such as the closed trail, connected and complete; some new features for Z-F-finite automata are presented. Further, it is shown that there is not any finite graph such that f be a part of the language of its Z-F-finite automata. Actually, it is proved that for every given graph, the Z-F-finite automata of it does not show any closed trail containing all edges for every zero forcing set, but if the graph G has been a closed trail containing all edges, then the Z-F-finite automata of it has a weak closed trail containing all edges. Some examples are also given to clarify these new notions.
The fiirst leap Zagreb index of a graph, is the sum of squares of the second degrees of vertices (number of their second neighbors), and the second leap Zagreb index is the sum of the products of the second degrees of pairs of adjacent vertices, and the third leap Zagreb index is the sum of the product of the degree and second degree of the vertices.
In this paper, we develop the revenue and cost efficiency models based on the FDH model. In the following, we will develop the proposed models for the two-stage network structure and obtain the desired scores of inputs and outputs by considering the input and output prices. An algorithm for measuring the revenue and cost efficiency is presented based on the ratio of inputs and outputs.
In this paper, we investigate the Single-Source Capacitated Multi-Facility Weber Problem. The aim is to locate several new facilities among existing customers and simultaneously allocate customers to the facilities. A Genetic Algorithm is proposed for solving the problem, in which a local search method is embedded. The proposed Genetic Algorithm is tested on existing data sets to evaluate its robustness over available methods in the literature.
In this paper, a numerical method for solving nonlinear fractional integral equations (NFIE) is introduced. This method is based on the new basis functions (NFs) introduced in [M. Paripour and et al., Numerical solution of nonlinear Volterra Fredholm integral equations by using new basis functions, Communications in Numerical Analysis, (2013)]. Since the conventional operational matrices for fractional kernels are singular, the definition of these matrices is modified. In order to increase the accuracy of approximating integrals, the operational matrices are exactly calculated and parametrically presented. Then, the solution procedure is proposed and applied on NFIE. Furthermore, the error analysis is performed and rate of convergence is obtained. In addition, various numerical examples are provided for a wide range of fractional orders and nonlinearity of integral equations. Comparison of the results with the exact solutions and those reported in previous studies indicate the capability, salient accuracy, and superiority of the proposed method over similar ones.
The present work is aimed to extend the common pollution indices into the fuzzy environment. For this purpose, a method was developed for converting the heavy metal contamination in soil by fuzzy numbers. Then, the most commonly used pollution indices are defined as fuzzy numbers by applying the alpha-cuts approach. To evaluate the degree of heavy metal contamination in a specific level, a degree of belonging was also suggested.
In this paper, the concepts of well-posednesses and Hadamard well-posedness for a family of mixed variational inequalities are studied. Also, some metric characterizations of them are presented and some relations between well-posedness and Hadamard well-posedness of a family of mixed variational inequalities is studied. Finally, a relation between well-posedness for the family of mixed variational inequalities and well-posedness for a family of inclusion problems is discussed.
Vehicular communications have been considered to be an enabler for numerous vehicle safety and information applications.Vehicle Social Networks (VSNs) are a type of ad-hoc networks which allows wireless communication between two adjacent vehicles. Routing and communicating with adjacent nodes are one of the problems in VSNs. A literature review indicated that the time limit to transmit data and route is a problem due to the geographical distance and speed..
In this paper, we study the uniqueness and multiplicity of the solutions of a strongly nonlinear mathematical model arising from chemical reactor theory. The analysis is based on the reproducing kernel Hilbert space method. The main aim of this work is to find how much information can be predicted using numerical computations. The dependence of the number of solutions on the parameters of the model is also studied. Furthermore, the analytical approximations of all branches of solutions can be calculated by the proposed method. The convergence of the proposed method is proved. Some numerical simulations are presented.
In this paper we introduce the concept of multiplication-like modules and we obtain some related results. We show that an R-module M is multiplication-like if and only if for each ideal I of R, I = (IM :R M). We prove that any multiplication-like module is faithful and r-multiplication. So we get that any flat and multiplication-like module is faithfully flat.
Objective: Improving sustainability in supply chains is one of the strategic objectives in the current business. Hence, firms have adopted new management strategies to achieve sustainability in their supply chain. Therefore, it is essential to assess the sustainability performance of the newly implemented management strategies. The purpose of this paper is to provide a model for assessing the sustainability performance of LARG supply chain management practices in the automotive supply chain using the dynamics system. Methods: LARG supply chain management practices were identified, by reviewing the literature and interviewing industry experts, prioritized using fuzzy analysis network process, and were eventually presented as an integrated approach to LARG supply chain management practices. Finally, the dynamic system has been used to assess the dynamics of LARG supply chain management practices and their impact on sustainable performance in the supply chain. Results: The research findings show that improved measures in the implementation of total quality management, just in time, flexible transportation lead to a more sustainable supply chain. The results of these measures show sustainability improvement in the supply chain. Conclusion: The results show that a lean strategy is very important for achieving sustainability in the supply chain. The proposed model helps industry managers and decision makers identify the results achieved from implementing LARG supply chain management practices and improving effective practices on sustainability in the supply chain by adopting policies.
In this paper, interval Legendre wavelet method is investigated to approximated the solution of the interval Volterra-Fredholm-Hammerstein integral equation. The shifted interval Legendre polynomials are introduced and based on interval Legendre wavelet method is defined. The existence and uniqueness theorem for the interval Volterra-Fredholm-Hammerstein integral equations is proved. Some examples show the effectiveness and efficiency of the approach.
In this paper, we present an approximate method to solve the solution of the second kind Volterra integral equations. This method is based on a previous scheme, applied by Maleknejad et al., [K. Maleknejad and Aghazadeh, Numerical solution of Volterra integral equations of the second kind with convolution kernel by using Taylor-series expansion method, Appl. Math. Comput. (2005)] to gain the approximate solution of the second kind Volterra integral equations with convolution kernel and Maleknejad et al. [K. Maleknejad and T. Damercheli, Improving the accuracy of solutions of the linear second kind volterra integral equations system by using the Taylor expansion method, Indian J. Pure Appl. Math. (2014)] to gain the approximate solutions of systems of second kind Volterra integral equations with the help of Taylor expansion method. The Taylor expansion method transforms the integral equation into a linear ordinary differential equation (ODE) which, in this case, requires specified boundary conditions. Boundary conditions can be determined using the integration technique instead of differentiation technique. This method is more stable than derivative method and can be implemented to obtain an approximate solution of the Volterra integral equation with smooth and weakly singular kernels. An error analysis for the method is provided. A comparison between our obtained results and the previous results is made which shows that the suggested method is accurate enough and more stable.
