Research Article
Mohammad Reza Zarrabi
Abstract
Drones are among the most valuable and versatile technologies in the world, with applications in a vast number of fields such as traffic control, agriculture, firefighting and rescue, and filmmaking, to name a few. As ...
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Drones are among the most valuable and versatile technologies in the world, with applications in a vast number of fields such as traffic control, agriculture, firefighting and rescue, and filmmaking, to name a few. As the development of unmanned aerial vehicles (UAVs) accelerates, the safety of UAVs becomes increasingly important. In this paper, a robust adaptive controller is designed to improve the safety of a hexa-rotor UAV, and a robust adaptive controller is developed to control our system. In doing so, the wind parameters from the aerodynamic forces and moments acting on the hexa-rotor are estimated using an observer with the adaptive algorithm. This proposed controller guarantees stability and reliable function in the midst of parametric and non-parametric uncertainties. The process's global stability and tracking convergence are investigated using the Lyapunov theorem. The performance and effectiveness of the proposed controller are tested through two simulation studies, which take into account external disturbances that are a function of time.
Research Article
Zahra Noori; Hamed Zhiani Rezai; Alireza Davoodi; Sohrab Kordrostami
Abstract
Data envelopment analysis models are able to rank decision-making units (DMUs) based on their efficiency scores. In spite of the fact that there exists a unique ranking of inefficient DMUs, ranking efficient DMUs is problematic. However, rather than ranking methods, ...
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Data envelopment analysis models are able to rank decision-making units (DMUs) based on their efficiency scores. In spite of the fact that there exists a unique ranking of inefficient DMUs, ranking efficient DMUs is problematic. However, rather than ranking methods, another way to choose one of the efficient units is to determine the most efficient DMU. Up to the present, many models have been proposed to rank DMUs and determine the most efficient one. These models require solving nonlinear or integer programs, which are NP-hard and time-consuming. Considering efficient DMU's characteristics, this paper proposes a procedure to find the most efficient DMU through some simple operations. The validity of the proposed approach is verified and tested via some numerical examples.
Research Article
Razieh Farokhzad Rostami
Abstract
Fixed point theorems can be used to prove the solvability of optimization problems, differential equations and equilibrium problems, and the intrinsic flexibility of probabilistic metric spaces makes it possible to extend the idea of contraction mapping in several inequivalent ways. ...
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Fixed point theorems can be used to prove the solvability of optimization problems, differential equations and equilibrium problems, and the intrinsic flexibility of probabilistic metric spaces makes it possible to extend the idea of contraction mapping in several inequivalent ways. In this paper, we extend very recent fixed point theorems in the setting of Menger probabilistic metric spaces. We present some fixed point theorems for self-mappings satisfying a generalized (ϕ , ψ ) - contractive condition in Menger probabilistic metric spaces which are contractions used extensively in global optimization problems. On the other hand, we consider a more general class of auxiliary functions in the contractivity condition and prove the existence of fixed points of non-expansive mappings on Menger probabilistic metric spaces.
Research Article
Hamidreza Ayoughi; Hossein Dehghani Poudeh; Abbas Raad; Davood Talebi
Abstract
In this paper, a stable multi-objective model of location, inventory, and supply chain routing is presented under conditions of uncertainty and using a passive defense approach. Parameters such as demand, cost of setting up the facility ...
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In this paper, a stable multi-objective model of location, inventory, and supply chain routing is presented under conditions of uncertainty and using a passive defense approach. Parameters such as demand, cost of setting up the facility and cost of maintaining inventory are considered uncertain and in the form of triangular fuzzy numbers. Also, in order to increase supply chain resilience, the characteristics and capabilities of passive defense in the supply chain, such as ``ready flow rate'', ``security of backup routes'', ``possibility of deployment of resources and equipment'', and ``the principle of dispersion for location'' are considered. Multipurpose, multipartite algorithms, based on the Pareto archive and genetic algorithm, are used to solve the model. The results of validation show that the proposed model is valid and feasible, and the proposed algorithm is also valid and converges to the optimal solution. Sample problems, in three groups of small, medium and large, are solved by two algorithms, and the results are compared based on quality, dispersion, uniformity and execution time. The results of this section show that in all cases, the multi-objective particle mass algorithm has a higher ability than the GA to produce solutions of higher quality and to explore and extract the scalable area of the solution. Also, the comparison of the execution times of the algorithms indicates that the multi-objective particle mass algorithm has a higher solution time.
Research Article
Hamed Soroush
Abstract
The purpose of this paper is to develop nonsmooth optimization problems (P) in which all emerging functions are assumed to be real-valued quasiconvex functions that are defined on a finite-dimensional Euclidean space. First, we introduce two linear optimization problems with the same optimal ...
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The purpose of this paper is to develop nonsmooth optimization problems (P) in which all emerging functions are assumed to be real-valued quasiconvex functions that are defined on a finite-dimensional Euclidean space. First, we introduce two linear optimization problems with the same optimal value of the considered problem. Then, we introduce a real-valued non-negative gap function for (P), and we provide some conditions which ensure that its null points are the same as the optimal solution of problem (P). The results are based on incident subdifferential, which is an important concept in the analysis of quasiconvex functions.
Research Article
Sayed Kahlil Ekrami
Abstract
In this paper, we prove that every orthogonally higher ring derivation is a higher ring derivation. Also we find the general solution of the pexider orthogonally higher ring derivations\begin{align*}\left\{\begin{array}{lr}f_n(x+y)=g_n(x)+h_n(y), ...
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In this paper, we prove that every orthogonally higher ring derivation is a higher ring derivation. Also we find the general solution of the pexider orthogonally higher ring derivations\begin{align*}\left\{\begin{array}{lr}f_n(x+y)=g_n(x)+h_n(y), \;\left\langle x,y \right\rangle =0,\\f_n(xy) = \sum_{i+j=n} g_i(x)h_j(y).\end{array}\right.\end{align*}Then we prove that for any approximate pexider orthogonally higher ring derivation under some control functions $ \varphi(x,y) $ and $ \psi(x,y) $, there exists a unique higher ring derivation $ D=\{d_n\}_{n=0}^\infty $, near $ \{f_n\}_{n=0}^\infty $, $ \{g_n\}_{n=0}^\infty $ and $ \{h_n\}_{n=0}^\infty $ estimated by $ \varphi $ and $ \psi $.
