88 research outputs found
Hybrid flow shop scheduling problems using improved fireworks algorithm for permutation
Prior studies are lacking which address permutation flow shop scheduling problems and hybrid flow shop scheduling problems together to help firms find the optimized scheduling strategy. The permutation flow shop scheduling problem and hybrid flow shop scheduling problems are important production scheduling types, which widely exist in industrial production fields. This study aimed to acquire the best scheduling strategy for making production plans. An improved fireworks algorithm is proposed to minimize the makespan in the proposed strategies. The proposed improved fireworks algorithm is compared with the fireworks algorithm, and the improvement strategies include the following: (1) A nonlinear radius is introduced and the minimum explosion amplitude is checked to avoid the waste of optimal fireworks; (2) The original Gaussian mutation operator is replaced by a hybrid operator that combines Cauchy and Gaussian mutation to improve the search ability; and (3) An elite group selection strategy is adopted to reduce the computing costs. Two instances from the permutation flow shop scheduling problem and hybrid flow shop scheduling problems were used to evaluate the improved fireworks algorithm’s performance, and the computational results demonstrate the improved fireworks algorithm’s superiority
Development of Hybrid PS-FW GMPPT Algorithm for improving PV System Performance Under Partial Shading Conditions
A global maximum power point tracking (MPPT) algorithm hybrid based on Particle Swarm Fireworks (PS-FW) algorithm is proposed which is formed with Particle Swarm Optimization and Fireworks Algorithm. The algorithm tracks the global maximum power point (MPP) when conventional MPPT methods fail due to occurrence of partial shading conditions. With the applied strategies and operators, PS-FW algorithm obtains superior performances verified under simulation and experimental setup with multiple cases of shading patterns
Swarm Intelligence and Metaphorless Algorithms for Solving Nonlinear Equation Systems
The simplicity, flexibility, and ease of implementation have motivated the
use of population-based metaheuristic optimization algorithms. By focusing
on two classes of such algorithms, particle swarm optimization (PSO)
and the metaphorless Jaya algorithm, this thesis proposes to explore the
capacity of these algorithms and their respective variants to solve difficult
optimization problems, in particular systems of nonlinear equations converted
into nonlinear optimization problems. For a numerical comparison to be
made, the algorithms and their respective variants were implemented and
tested several times in order to achieve a large sample that could be used
to compare these approaches as well as find common methods that increase
the effectiveness and efficiency of the algorithms. One of the approaches
that was explored was dividing the solution search space into several
subspaces, iteratively running an optimization algorithm on each subspace,
and comparing those results to a greatly increased initial population. The
insights from these previous experiments were then used to create a new
hybrid approach to enhance the capabilities of the previous algorithms, which
was then compared to preexisting alternatives.A simplicidade, flexibilidade e facilidade de implementa¸c˜ao motivou o uso
de algoritmos metaheur´ısticos de optimiza¸c˜ao baseados em popula¸c˜oes.
Focando-se em dois destes algoritmos, optimiza¸c˜ao por exame de part´ıculas
(PSO) e no algoritmo Jaya, esta tese prop˜oe explorar a capacidade destes
algoritmos e respectivas variantes para resolver problemas de optimiza¸c˜ao de
dif´ıcil resolu¸c˜ao, em particular sistemas de equa¸c˜oes n˜ao lineares convertidos
em problemas de optimiza¸c˜ao n˜ao linear. Para que fosse poss´ıvel fazer
uma compara¸c˜ao num´erica, os algoritmos e respectivas variantes foram
implementados e testados v´arias vezes, de modo a que fosse obtida uma
amostra suficientemente grande de resultados que pudesse ser usada para
comparar as diferentes abordagens, assim como encontrar m´etodos que
melhorem a efic´acia e a eficiˆencia dos algoritmos. Uma das abordagens
exploradas foi a divis˜ao do espa¸co de procura em v´arios subespa¸cos,
iterativamente correndo um algoritmo de optimiza¸c˜ao em cada subespa¸co,
e comparar esses resultados a um grande aumento da popula¸c˜ao inicial, o
que melhora a qualidade da solu¸c˜ao, por´em com um custo computacional
acrescido. O conhecimento resultante dessas experiˆencias foi utilizado na
cria¸c˜ao de uma nova abordagem hibrida para melhorar as capacidades dos
algoritmos anteriores, a qual foi comparada a alternativas pr´e-existentes
A NOVEL METAHEURISTIC ALGORITHM: DYNAMIC VIRTUAL BATS ALGORITHM FOR GLOBAL OPTIMIZATION
A novel nature-inspired algorithm called the Dynamic Virtual Bats Algorithm (DVBA)
is presented in this thesis. DVBA is inspired by a bat’s ability to manipulate frequency
and wavelength of the emitted sound waves when hunting. A role based search has been
developed to improve the diversification and intensification capability of standard Bat
Algorithm (BA). Although DVBA is inspired from bats, like BA, it is conceptually very
different from BA. BA needs a huge number of population size; however, DVBA employs
just two bats to handle the ”exploration and exploitation” conflict which is known as a
real challenge for all optimization algorithms.
Firstly, we study bat’s echolocation ability and next, the most known bat-inspired
algorithm and its modified versions are analyzed. The contributions of this thesis start
reading and imitating bat’s hunting strategies with different perspectives. In the DVBA, there are only two bats: explorer and exploiter bat. While the explorer bat explores the
search space, the exploiter bat makes an intensive search of the local with the highest
probability of locating the desired target. Depending on their location, bats exchange the
roles dynamically.
The performance of the DVBA is extensively evaluated on a suite of 30 bound-constrained
optimization problems from Congress of Evolutionary Computation (CEC) 2014 and
compared with 4 classical optimization algorithm, 4 state-of-the-art modified bat
algorithms, and 5 algorithms from a special session at CEC2014. In addition, DVBA
is tested on supply chain cost problem to see its performance on a complicated real world
problem. The experimental results demonstrated that the proposed DVBA outperform, or
is comparable to, its competitors in terms of the quality of final solution and its convergence
rates.Epoka Universit
Enhancement of bees algorithm for global optimisation
This research focuses on the improvement of the Bees Algorithm, a swarm-based nature-inspired optimisation algorithm that mimics the foraging behaviour of honeybees. The algorithm consists of exploitation and exploration, the two key elements of optimisation techniques that help to find the global optimum in optimisation problems. This thesis presents three new approaches to the Bees Algorithm in a pursuit to improve its convergence speed and accuracy.
The first proposed algorithm focuses on intensifying the local search area by incorporating Hooke and Jeeves’ method in its exploitation mechanism. This direct search method contains a pattern move that works well in the new variant named “Bees Algorithm with Hooke and Jeeves” (BA-HJ). The second proposed algorithm replaces the randomly generated recruited bees deployment method with chaotic sequences using a well-known logistic map. This new variant called “Bees Algorithm with Chaos” (ChaosBA) was intended to use the characteristic of chaotic sequences to escape from local optima and at the same time maintain the diversity of the population. The third improvement uses the information of the current best solutions to create new candidate solutions probabilistically using the Estimation Distribution Algorithm (EDA) approach. This new version is called Bees Algorithm with Estimation Distribution (BAED).
Simulation results show that these proposed algorithms perform better than the standard BA, SPSO2011 and qABC in terms of convergence for the majority of the tested benchmark functions. The BA-HJ outperformed the standard BA in thirteen out of fifteen benchmark functions and is more effective in eleven out of fifteen benchmark functions when compared to SPSO2011 and qABC. In the case of the ChaosBA, the algorithm outperformed the standard BA in twelve out of fifteen benchmark functions and significantly better in eleven out of fifteen test functions compared to qABC and SPSO2011. BAED discovered the optimal solution with the least number of evaluations in fourteen out of fifteen cases compared to the standard BA, and eleven out of fifteen functions compared to SPSO2011 and qABC. Furthermore, the results on a set of constrained mechanical design problems also show that the performance of the proposed algorithms is comparable to those of the standard BA and other swarm-based algorithms from the literature
Metaheuristic Optimization of Power and Energy Systems: Underlying Principles and Main Issues of the `Rush to Heuristics'
In the power and energy systems area, a progressive increase of literature contributions that contain applications of metaheuristic algorithms is occurring. In many cases, these applications are merely aimed at proposing the testing of an existing metaheuristic algorithm on a specific problem, claiming that the proposed method is better than other methods that are based on weak comparisons. This ‘rush to heuristics’ does not happen in the evolutionary computation domain, where the rules for setting up rigorous comparisons are stricter but are typical of the domains of application of the metaheuristics. This paper considers the applications to power and energy systems and aims at providing a comprehensive view of the main issues that concern the use of metaheuristics for global optimization problems. A set of underlying principles that characterize the metaheuristic algorithms is presented. The customization of metaheuristic algorithms to fit the constraints of specific problems is discussed. Some weaknesses and pitfalls that are found in literature contributions are identified, and specific guidelines are provided regarding how to prepare sound contributions on the application of metaheuristic algorithms to specific problems
Evolutionary Computation 2020
Intelligent optimization is based on the mechanism of computational intelligence to refine a suitable feature model, design an effective optimization algorithm, and then to obtain an optimal or satisfactory solution to a complex problem. Intelligent algorithms are key tools to ensure global optimization quality, fast optimization efficiency and robust optimization performance. Intelligent optimization algorithms have been studied by many researchers, leading to improvements in the performance of algorithms such as the evolutionary algorithm, whale optimization algorithm, differential evolution algorithm, and particle swarm optimization. Studies in this arena have also resulted in breakthroughs in solving complex problems including the green shop scheduling problem, the severe nonlinear problem in one-dimensional geodesic electromagnetic inversion, error and bug finding problem in software, the 0-1 backpack problem, traveler problem, and logistics distribution center siting problem. The editors are confident that this book can open a new avenue for further improvement and discoveries in the area of intelligent algorithms. The book is a valuable resource for researchers interested in understanding the principles and design of intelligent algorithms
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