Optimization in science and engineering
Nazila Nikdel
Abstract
Purpose: Nowadays, robotic systems are widely used in advanced industrial operations. Therefore, making appropriate control decisions to ensure the efficiency of these systems is critical. Criteria such as operation time and response speed, control cost, and system error need to be controlled by providing ...
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Purpose: Nowadays, robotic systems are widely used in advanced industrial operations. Therefore, making appropriate control decisions to ensure the efficiency of these systems is critical. Criteria such as operation time and response speed, control cost, and system error need to be controlled by providing appropriate methods to ensure the successful performance of industrial operations. Therefore, this article pursues two main objectives: 1) controlling the robotic system by presenting a method based on fractional-order calculus so that it can control the system despite its complexity and non-linearity, 2) presenting the meta-heuristic algorithm "Improved Grey Wolf" to optimize the system response.Methodology: First, the mathematical model of the robot is presented based on Lagrange rules, and then the fractional-order calculus is used to design the controller. In addition, the efficiency of the grey wolf algorithm is increased with the introduction of an improved method.Findings: Different cost functions based on the main performance criteria of the robotic system are introduced, and an improved algorithm is applied to them. The comparison results of the proposed algorithm and other algorithms, indicate its satisfying performance. In addition, the efficiency of the fractional-order controller is compared with its integer-order counterpart, and the results show a significant improvement in system performance.Originality/Value: The proposed controller can control the system well despite its complexity and non-linearity. In addition, inspired by the Grey Wolf algorithm, an improved optimization method is proposed that can increase the efficiency of the controlled system. Numerical results show the satisfying performances of the proposed controller and the improved optimization algorithm.
Robust optimization
Fahimeh Baroughi; Soudabeh Seyyedi Ghomi
Abstract
In this paper the robust path centdian problem is investigated on tree networks with the same interval vertex weights for the both path center and path median problems. The used objective function in this paper is the simple sum of path median and path center problems. In the past research works the ...
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In this paper the robust path centdian problem is investigated on tree networks with the same interval vertex weights for the both path center and path median problems. The used objective function in this paper is the simple sum of path median and path center problems. In the past research works the vertex weights for the both path median and path center location problems are disjoint. The used approach to compute the robust solution is the minmax regret criterion. In this method for any selected path on the tree, the maximum value of regret is minimized for all possible events of vertex weights. Using the minmax regret criterion, an algorithm with O(n^5) time complexity is presented to obtain a robust solution of the robust path centdian problem on tree networks. In this paper using the worst case scenarios for the path median and path center we obtain the worst case scenarios of robust centdian problem. Then we obtain a robust solution for this problem.
meta-heuristic algorithms
Hojatollah Rajabi Moshtaghi; Abbass Toloie-Eshlaghy; Mohammad Reza Motadel
Abstract
Purpose: In recent years, meta-heuristic algorithms and their application in solving complicated, nonlinear, and high dimensions problems have increased dramatically and the fact that meta-heuristic algorithms are used to solve complex and changing problems of real life, has caused the algorithms world ...
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Purpose: In recent years, meta-heuristic algorithms and their application in solving complicated, nonlinear, and high dimensions problems have increased dramatically and the fact that meta-heuristic algorithms are used to solve complex and changing problems of real life, has caused the algorithms world and their design to be very dynamic and alive; that's why new algorithms are constantly being created. Hence, the purpose of this research is to introduce a novel meta-heuristic algorithm called Military Optimization Algorithm (MOA). Methodology: Inspired by military operations, the proposed algorithm was designed and presented. After coding, Standard test functions and benchmark algorithms were determined to evaluate the performance of the algorithm.Findings: The performance of new algorithm is analyzed by 23 standard test functions and compared to 8 benchmark meta-heuristic algorithms including: Genetic Algorithm, Particle Swarm Optimization, Artificial Bee Colony, Shuffled Frog Leaping Algorithm, and Imperialist Competitive Algorithm, Grey Wolf Optimizer, Whale Optimization Algorithm, and Grasshopper Optimization Algorithm, by considering three indices of "average answers", "time complexity of algorithm (speed)" and "Convergence speed/ time". The results show the excellent performance of the proposed algorithm.Originality/Value: In this paper, inspired by military operations, a novel meta-heuristic algorithm called MOA is introduced. It is population-based and stable with "random search", "dividing solution space into several regions and allocating a part of the population to each region", "cavalry search", and "infantry search".
Decisions in new businesses
Elham Fazelli Veisari; mohamad javad Taghipourian; Reza Tavoli; Ghydar Ghanbarzade
Abstract
The purpose of this study is to identify the components and develop a model to provide rules for optimizing viral marketing in businesses. It is an applied research and in terms of method, it is mixed (quantitative and qualitative). The statistical population of the research in the qualitative part includes ...
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The purpose of this study is to identify the components and develop a model to provide rules for optimizing viral marketing in businesses. It is an applied research and in terms of method, it is mixed (quantitative and qualitative). The statistical population of the research in the qualitative part includes 15 people in the three generations X, Y and Z (Millennium marketing generation) and in the quantitative part includes 460 online buyers. Data collection tools were used in the qualitative part of projection technique and in-depth interview. Interviews were analyzed and summarized using MAXQDA software, through which six components were identified, and then in a small part of 12 experts were used to determine the index of CVR, and then exploratory factor analysis was performed by SPSS software. Because selecting the most effective new components of viral marketing can have a huge impact on the accuracy of the viral marketing model in online businesses, To identify the most effective components, genetic metaheuristic algorithm was used, which is the software used in this section, WEKA and RAPIDMINER. Finally, the rules of viral marketing optimization were identified using the decision tree method. Findings in the qualitative section indicate that online persuasion, online trust, online support, online services, online attractiveness and online risk-taking are components of viral marketing. In the quantitative section and genetic algorithm, it was shown that the online risk component could not be used as an effective component for modeling and extracting viral marketing rules, so it was removed from the six components.