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Publication Date: 2025
International Journal of Energy Research (1099114X)2025(1)
This article introduces a novel optimization approach grounded in fuzzy logic, which transforms the multi-objective optimization problem into a single-objective one. Instead of providing a Pareto front, this method delivers a final optimal point based on predefined design priorities. The proposed methodology is applied to optimize illuminance, heating, and cooling setpoints in an office building across six cities with diverse climates to assess its performance under various conditions. The multi-objective optimization of these setpoints represents a novel contribution to smart building design. Compared to the NSGA-II method, the newly introduced approach exhibits simplicity and achieves a 50% reduction in computational time. The method leverages user experiences in formulating fuzzy rules, yielding more optimal solutions compared to the NSGA-II. The proposed method combines neural network, fuzzy logic, and genetic algorithm to create an efficient and intelligent framework for fast and accurate multi-objective optimization in energy-related problems. Copyright © 2025 Hamed Bagheri-Esfeh and Mohammad Reza Setayandeh. International Journal of Energy Research published by John Wiley & Sons Ltd.
Publication Date: 2021
Iranian Journal Of Fuzzy Systems (17350654)18(5)pp. 181-198
A novel strategy to design optimization is expressed using the fuzzy preference function concept. This method efficiently uses the designer’s experiences by preference functions and it is also able to transform a constrained multi-objective optimization problem into an unconstrained single-objective optimization problem. These two issues are the most important features of the proposed method which using them, you can achieve a more practical solution in less time. To implement the proposed method, two design optimizations of an unmanned aerial vehicle are considered which are: deterministic and non-deterministic optimizations. The optimization problem in this paper is a constrained multi-objective problem that with attention to the ability of genetic algorithm, this algorithm is selected as the optimizer. Uncertainties are considered and the Monte Carlo simulation (MCS) method is used for uncertainties modeling. The obtained results show a good performance of this technique in achieving optimal and robust solutions. © 2021, University of Sistan and Baluchestan. All rights reserved.
Publication Date: 2021
Journal of Aerospace Engineering (08931321)34(4)
Despite the many advantages of the design optimization technique, this method is costly for real engineering problems. This cost will increase sharply for issues with a multidisciplinary and uncertain nature and more than one objective function. In this paper, the metamodel concept has been used to overcome this problem. Because of the ability of neural networks to approximate the behavior of complex engineering systems, this tool has been used to create a surrogate model. Because multidisciplinary design optimization and robust design optimization methods have been used in this study and according to the high cost of the multidisciplinary analysis module, a surrogate model of this module has been made to reduce the imposed costs. To show the capability of the considered approach, robust multidisciplinary design optimization of an unmanned aerial vehicle (UAV) has been done. Take-off weight and cruise drag are the considered objective functions in this study, and the nondominated sorting genetic algorithm (NSGA-I) has been used for minimization of them. The optimization results show that the use of the metamodeling concept has reduced computational costs by 94.1%. © 2021 American Society of Civil Engineers.
Publication Date: 2020
Soft Computing (14327643)24(16)pp. 12429-12448
A new strategy for solving multidisciplinary design optimization problems is presented in this paper. The main idea of this approach is based on the use of designer experiences and attention to his/her preferences during design optimization which is implemented using a concept called the fuzzy preference function. Two important advantages of this approach are: (1) using the experiences of expert people during optimization and (2) transforming a constrained multiobjective design optimization problem into an unconstrained single-objective design optimization problem. The multidisciplinary design optimization of an unmanned aerial vehicle (UAV) is considered to show the performance of the proposed methodology. The optimization problem in this case study is a constrained two-objective problem (minimization of takeoff weight and drag of the cruise phase), and the genetic algorithm (GA) is utilized as the optimizer. Performance, weight, aerodynamics, center of gravity, trim and dynamic stability are the considered modules in the multidisciplinary analysis that are modeled using empirical and semiempirical equations. The optimization results show that the proposed strategy has been able to offer an optimal design where has higher performance relative to other methods from the point of view of objective functions, low computational cost and simplicity of implementation. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
Publication Date: 2018
Journal of Aerospace Technology and Management (21759146)10
In this study, an efficient methodology is proposed for robust design optimization by using preference function and fuzzy logic concepts. In this method, the experience of experts is used as an important source of information during the design optimization process. The case study in this research is wing design optimization of Boeing 747. Optimization problem has two objective functions (wing weight and wing drag) so that they are transformed into new forms of objective functions based on fuzzy preference functions. Design constraints include transformation of fuel tank volume and lift coefficient into new constraints based on fuzzy preference function. The considered uncertainties are cruise velocity and altitude, which Monte Carlo simulation method is used for modeling them. The non-dominated sorting genetic algorithm is used as the optimization algorithm that can generate set of solutions as Pareto frontier. Ultimate distance concept is used for selecting the best solution among Pareto frontier. The results of the probabilistic analysis show that the obtained configuration is less sensitive to uncertainties. © 2018, Journal of Aerospace Technology and Management. All rights reserved.
Publication Date: 2018
Chinese Journal of Aeronautics (10009361)31(12)pp. 2248-2259
This paper presents a Fuzzy Preference Function-based Robust Multidisciplinary Design Optimization (FPF-RMDO) methodology. This method is an effective approach to multidisciplinary systems, which can be used to designer experiences during the design optimization process by fuzzy preference functions. In this study, two optimizations are done for Predator MQ-1 Unmanned Aerial Vehicle (UAV): (A) deterministic optimization and (B) robust optimization. In both problems, minimization of takeoff weight and drag is considered as objective functions, which have been optimized using Non-dominated Sorting Genetic Algorithm (NSGA). In the robust design optimization, cruise altitude and velocity are considered as uncertainties that are modeled by the Monte Carlo Simulation (MCS) method. Aerodynamics, stability and control, mass properties, performance, and center of gravity are used for multidisciplinary analysis. Robust design optimization results show 46% and 42% robustness improvement for takeoff weight and cruise drag relative to optimal design respectively. © 2018 Chinese Society of Aeronautics and Astronautics
