Traditional Evolutionary Algorithms Research Articles

MOANA: Multi-Objective Ant Nesting Algorithm for Optimization Problems

This paper presents the Multi-Objective Ant Nesting Algorithm (MOANA), a novel extension of the Ant Nesting Algorithm (ANA), specifically designed to address multi-objective optimization problems (MOPs). MOANA incorporates adaptive mechanisms, such as deposition weight parameters, to balance exploration and exploitation, while a polynomial mutation strategy ensures diverse and high-quality solutions. The algorithm is evaluated on standard benchmark datasets, including ZDT functions and the IEEE Congress on Evolutionary Computation (CEC) 2019 multi-modal benchmarks. Comparative analysis against state-of-the-art algorithms like MOPSO, MOFDO, MODA, and NSGA-III demonstrates MOANA's superior performance in terms of convergence speed and Pareto front coverage. Furthermore, MOANA's applicability to real-world engineering optimization, such as welded beam design, showcases its ability to generate a broad range of optimal solutions, making it a practical tool for decision-makers. MOANA addresses key limitations of traditional evolutionary algorithms by improving scalability and diversity in multi-objective scenarios, positioning it as a robust solution for complex optimization tasks.

Adaptive search for broad attention based vision transformers

Vision Transformer (ViT) has prevailed among computer vision tasks for its powerful capability of image representation recently. Frustratingly, the manual design of efficient architectures for ViTs can be laborious, often involving repetitive trial and error processes. Furthermore, the exploration of lightweight ViTs remains limited, resulting in inferior performance compared to convolutional neural networks. To tackle these challenges, we propose Adaptive Search for Broad attention based Vision Transformers, called ASB, which automates the design of efficient ViT architectures by utilizing the broad search space and an adaptive evolutionary algorithm. The broad search space facilitates the exploration of a novel connection paradigm, enabling more comprehensive integration of attention information to improve ViT performance. Additionally, an efficient adaptive evolutionary algorithm is developed to efficiently explore architectures by dynamically learning the probability distribution of candidate operators. Our experimental results demonstrate that the adaptive evolution in ASB efficiently learns excellent lightweight models, achieving a 55% improvement in convergence speed over traditional evolutionary algorithms. Moreover, the effectiveness of ASB is validated across several visual tasks. For instance, on ImageNet classification, the searched model attains a performance of 77.8% with 6.5M parameters and outperforms state-of-the-art models, including EfficientNet and EfficientViT networks. On mobile COCO panoptic segmentation, our approach delivers 43.7% PQ. On mobile ADE20K semantic segmentation, our method attains 40.9% mIoU. The code and pre-trained models will be available soon in ASB-Code.

A two-stage accelerated search strategy for large-scale multi-objective evolutionary algorithm

Since large-scale multi-objective problems (LSMOPs) have huge decision variables, the traditional evolutionary algorithms are facing difficulties of low exploitation efficiency and high exploration costs in solving LSMOPs. Therefore, this paper proposes an evolutionary strategy based on two-stage accelerated search optimizers (ATAES). Specifically, a convergence optimizer is devised in the first stage, while a three-layer lightweight convolutional neural network model is built, and the population is homogenized into two subsets, the diversity subset, and the convergence subset, which serve as input nodes and the expected output nodes of the neural network, respectively. Then, by constantly backpropagating the gradient, a satisfactory individual will be produced. Once exploitation stagnation is discovered in the first phase, the second phase will be run, where a diversity optimizer using a differential optimization algorithm with opposite learning is suggested to increase the exploration range of candidate solutions and thereby increase the population's diversity. Finally, to validate the algorithm's performance, on multi-objective LSMOP and DTLZ benchmark suits with decision variable quantities of 100, 300, 500, and 1000, the ATAES demonstrated its superiority with other advanced multi-objective evolutionary algorithms.

ERRT-GA: Expert Genetic Algorithm with Rapidly Exploring Random Tree Initialization for Multi-UAV Path Planning

In unmanned aerial vehicle (UAV) path planning, evolutionary algorithms are commonly used due to their ability to handle high-dimensional spaces and wide generality. However, traditional evolutionary algorithms have difficulty with population initialization and may fall into local optima. This paper proposes an improved genetic algorithm (GA) based on expert strategies, including a novel rapidly exploring random tree (RRT) initialization algorithm and a cross-variation process based on expert guidance and the wolf pack search algorithm. Experimental results on baseline functions in different scenarios show that the proposed RRT initialization algorithm improves convergence speed and computing time for most evolutionary algorithms. The expert guidance strategy helps algorithms jump out of local optima and achieve suboptimal solutions that should have converged. The ERRT-GA is tested for task assignment, path planning, and multi-UAV conflict detection, and it shows faster convergence, better scalability to high-dimensional spaces, and a significant reduction in task computing time compared to other evolutionary algorithms. The proposed algorithm outperforms most other methods and shows great potential for UAV path planning problems.

Objective contribution decomposition method and multi-population optimization strategy for large-scale multi-objective optimization problems

As problem complexity and data dimensionality increase, practical problems tend to have a large number of variables. Large-scale multi-objective optimization problems (LSMOPs) are a complex and difficult class of problems with numerous decision variables to be optimized. In addressing these problems using traditional evolutionary algorithms, achieving convergence is often difficult. The decomposition of decision variables and optimization is a more intuitive way to deal with this problem, which reduces the size of the problem to some extent. Thus, in this study, an objective contribution decomposition method and multi-population optimization strategy are proposed for handling LSMOPs. First, the decision variables are decomposed according to their contribution to the objectives. Further decomposition is performed based on the interactions among the decision variables. Then, multiple populations are generated to optimize the variable group and determine the information interaction among the subpopulations. In experimental results, the performance of the proposed algorithm was competitive in comparisons with six state-of-the-art algorithms.

A Knowledge-Guided Competitive Co-Evolutionary Algorithm for Feature Selection

In real-world applications, feature selection is crucial for enhancing the performance of data science and machine learning models. Typically, feature selection is a complex combinatorial optimization problem and a multi-objective optimization problem. Its primary goals are to reduce the dimensionality of the dataset and enhance the performance of machine learning algorithms. The selection of features in high-dimensional datasets is challenging due to the intricate relationships between features, which pose significant challenges to the performance and computational efficiency of algorithms. This paper introduces a Knowledge-Guided Competitive Co-Evolutionary Algorithm (KCCEA) for feature selection, especially for high-dimensional features. In the proposed algorithm, we make improvements to the foundational dominance-based multi-objective evolutionary algorithm in two aspects. First, the use of feature correlation as knowledge to guide evolution enhances the search speed and quality of traditional multi-objective evolutionary algorithm solutions. Second, a dynamically allocated competitive–cooperative evolutionary mechanism is proposed, integrating the improved knowledge-guided evolution with traditional evolutionary algorithms, further enhancing the search efficiency and diversity of solutions. Through rigorous empirical testing on various datasets, the KCCEA demonstrates superior performance compared to basic multi-objective evolutionary algorithms, providing effective solutions to multi-objective feature selection problems while enhancing the interpretability and effectiveness of prediction models.

Efficient large-scale biomedical ontology matching with anchor-based biomedical ontology partitioning and compact geometric semantic genetic programming

Biomedical ontology offers a structured framework to model the biomedical knowledge in a machine-readable format. However, the heterogeneity inherent in biomedical ontologies hinders their communication. Biomedical Ontology Matching (BOM) can address this issue by identifying equivalent concepts in biomedical ontologies. Recently, Evolutionary Algorithms (EAs) based matching techniques have exhibited their effectiveness in finding high-quality matching results. However, due to the vast number of entities, and intricate relationships between entities, it is difficult for traditional EAs to efficiently solve the BOM problem. To tackle this challenge, this paper proposes an efficient BOM method to automatically match large-scale biomedical ontologies. First, a novel anchor-based biomedical ontology partitioning method is developed to transform the large-scale BOM problem into several small-scale matching tasks, reducing the search space of the matching phase. Second, a new Compact Geometric Semantic Genetic Programming (CGSGP) is proposed to efficiently construct high-level Similarity Feature for BOM, which can significantly reduce the computational complexity. Lastly, a new fitness function composed of the approximated evaluation metric and the Dominance Improvement Ratio (DIR) is introduced, which can overcome the solution’s bias improvement and enable the simultaneous matching of multiple pairs of sub-ontologies without requiring the standard alignment. The experiment verifies our approach’s performance on the Ontology Alignment Evaluation Initiative (OAEI)’s Anatomy, Large Biomed and Disease and Phenotype datasets. The experimental results show that our method can efficiently determine high-quality BOM results across different test cases, whose performance significantly outperforms the state-of-the-art BOM techniques.

Dual-stage and dual-population cooperative evolutionary algorithm for solving constrained multiobjective problems

During the search process, the characteristics of the feasible regions encountered by the population continually change in Constrained Multiobjective Optimization Problems (CMOPs). This variability poses a challenge for traditional evolutionary algorithms, which often struggle to adapt to the diverse problem characteristics of the encountered feasible regions. To overcome this limitation, we propose a Dual-Stage and Dual-Population Cooperative Evolutionary Algorithm (DDCEA) to address CMOPs characterized by diverse feasible regions. DDCEA employs a dual-stage mechanism to adapt the offspring generation strategy and establishes two distinct populations to evaluate offspring using constraint-sensitive and constraint-free strategies. Comparative analyses reveal that DDCEA surpasses chosen state-of-the-art CMOEAs in adapting to the changing feasible regions and then approximating the constrained Pareto fronts.

Towards Running Time Analysis of Interactive Multi-Objective Evolutionary Algorithms

Evolutionary algorithms (EAs) are widely used for multi-objective optimization due to their population-based nature. Traditional multi-objective EAs (MOEAs) generate a large set of solutions to approximate the Pareto front, leaving a decision maker (DM) with the task of selecting a preferred solution. However, this process can be inefficient and time-consuming, especially when there are many objectives or the DM has subjective preferences. To address this issue, interactive MOEAs (iMOEAs) combine decision making into the optimization process, i.e., update the population with the help of the DM. In contrast to their wide applications, there has existed only two pieces of theoretical works on iMOEAs, which only considered interactive variants of the two simple single-objective algorithms, RLS and (1+1)-EA. This paper provides the first running time analysis (the essential theoretical aspect of EAs) for practical iMOEAs. Specifically, we prove that the expected running time of the well-developed interactive NSGA-II (called R-NSGA-II) for solving the OneMinMax, OneJumpZeroJump problems are all asymptotically faster than the traditional NSGA-II. Meanwhile, we present a variant of OneMinMax, and prove that R-NSGA-II can be exponentially slower than NSGA-II. These results provide theoretical justification for the effectiveness of iMOEAs while identifying situations where they may fail. Experiments are also conducted to validate the theoretical results.

An XGBoost-assisted evolutionary algorithm for expensive multiobjective optimization problems

Many expensive optimization problems exist in various real-world applications. However traditional evolutionary algorithms are inadequate for solving these problems directly. Surrogate-assisted evolutionary algorithm (SAEA) can effectively solve expensive optimization problems using computationally inexpensive surrogate models. However, both the Kriging and ensemble models most SAEAs adopted have limited uncertainty of prediction, especially for expensive multiobjective optimization problems (EMOPs). To enhance the optimization performance of SAEA for EMOPs, this paper proposes a new XGBoost-assisted evolutionary algorithm, calling XGBEA. Specifically, XGBoost is used as the surrogate model, and a neighborhood density selection strategy based on a mixed population and archive space (NDS-MPA) is proposed to measure the uncertainties of individuals. XGBoost helps to best fit objective functions with different fitness landscapes. NDS-MPA selects non-dominated individuals with minimal density for re-evaluation, incorporating considerations of convergence, diversity and uncertainty. Experimental results on two well-studied benchmarks demonstrated the superiority of XGBEA over seven state-of-the-art SAEAs.

Transfer learning based covariance matrix adaptation for evolutionary many-objective optimization

Evolutionary Algorithms (EA) have proven successful in solving Multi- and Many-objective Optimization Problems (MOPs/MaOPs) in numerous application areas. However, the various linkages among the decision variables may have posed a challenge for traditional evolutionary algorithms for solving such problems. In this paper, a transfer learning based covariance matrix adaptation algorithm, shortened as TL-M2M-CMA, is proposed to handle MOPs/MaOPs with complex decision variable linkage. In TL-M2M-CMA, the search population is first decomposed into a set of subpopulations and each subpopulation corresponds to a specific part of the Pareto-optimal Front (PF) of the MOP/MaOP. During the search, a covariance matrix adaptation process is utilized to learn the linkage among the decision variables, and then the covariance matrix is incorporated into the crossover and mutation operators for better efficiency. To facilitate performance comparison, a set of scalable MOP test instances with various linkage complexities is constructed for experimental studies. The performance of the proposed TL-M2M-CMA on these constructed instances is verified by comparing it to the performance of five state-of-the-art EA methods.

Population Dynamics in Genetic Programming for Dynamic Symbolic Regression

This paper investigates the application of genetic programming (GP) for dynamic symbolic regression (SR), addressing the challenge of adapting machine learning models to evolving data in practical applications. Benchmark instances with changing underlying functions over time are defined to assess the performance of a genetic algorithm (GA) as a traditional evolutionary algorithm and an age-layered population structure (ALPS) as an open-ended evolutionary algorithm for dynamic symbolic regression. This study analyzes population dynamics by examining variable frequencies and impact changes over time in response to dynamic shifts in the training data. The results demonstrate the effectiveness of both the GA and ALPS in handling changing data, showcasing their ability to recover and evolve improved solutions after an initial drop in population quality following data changes. Population dynamics reveal that variable impacts respond rapidly to data changes, while variable frequencies shift gradually across generations, aligning with the indirect measure of fitness represented by variable impacts. Notably, the GA shows a strong dependence on mutation to avoid variables becoming permanently extinct, contrasting with the ALPS’s unexpected insensitivity to mutation rates owing to its reseeding mechanism for effective variable reintroduction.

Evolutionary algorithms guided by Erdős-Rényi complex networks.

This article proposes an evolutionary algorithm integrating Erdős-Rényi complex networks to regulate population crossovers, enhancing candidate solution refinement across generations. In this context, the population is conceptualized as a set of interrelated solutions, resembling a complex network. The algorithm enhances solutions by introducing new connections between them, thereby influencing population dynamics and optimizing the problem-solving process. The study conducts experiments comparing four instances of the traditional optimization problem known as the Traveling Salesman Problem (TSP). These experiments employ the traditional evolutionary algorithm, alternative algorithms utilizing different types of complex networks, and the proposed algorithm. The findings suggest that the approach guided by an Erdős-Rényi dynamic network surpasses the performance of the other algorithms. The proposed model exhibits improved convergence rates and shorter execution times. Thus, strategies based on complex networks reveal that network characteristics provide valuable information for solving optimization problems. Therefore, complex networks can regulate the decision-making process, similar to optimizing problems. This work emphasizes that the network structure is crucial in adding value to decision-making.

An improved linear prediction evolution algorithm based on topological opposition-based learning for optimization

Prediction-based evolutionary algorithm is one of the emerging category of meta-heuristic optimization techniques. The improved linear prediction evolution algorithm (ILPE) is a recently developed meta-heuristic optimization technique that draws inspiration from non-linear least-square fitting models. This article implements the concept of topological opposition-based learning, which was first applied in grey prediction evolutionary algorithms to the ILPE. In traditional evolutionary algorithms, after employing the mutation and crossover operator, it generates trial populations. The proposed algorithm constructs a new reproduction operator using the non-linear least square fitting model with topological opposition-based learning to generate trial individuals. This reproduction operator considers the population series as a time series and uses the topological opposition-based non-linear least square fitting model to predict the next generation of populations. The efficiency and accuracy of the algorithm are demonstrated through numerical experiments on CEC2014 and CEC2017 benchmark functions. The results of these experiments show that the proposed algorithm is highly effective in solving optimization problems.•An improved linear prediction evolution algorithm based on topological opposition based learning (TILPE) is proposed.•The proposed strategy treat the the population series as a time series.•To validate the efficacy of TILPE, CEC2014 and CEC2017 benchmark functions are used.

Surrogate-assisted level-based learning evolutionary search for geothermal heat extraction optimization

An enhanced geothermal system is essential to provide sustainable and long-term geothermal energy supplies and reduce carbon emissions. Optimal well-control scheme for effective heat extraction and improved heat sweep efficiency plays a significant role in geothermal development. However, the optimization performance of most existing optimization algorithms deteriorates as dimension increases. To solve this issue, a novel surrogate-assisted level-based learning evolutionary search algorithm (SLLES) is proposed for heat extraction optimization of enhanced geothermal system. SLLES consists of classifier-assisted level-based learning pre-screen part and local evolutionary search part. The cooperation of the two parts has realized the balance between the exploration and exploitation during the optimization process. After iteratively sampling from the design space, the robustness and effectiveness of the algorithm are proven to be improved significantly. To the best of our knowledge, the proposed algorithm holds state-of-the-art simulation-involved optimization framework. Comparative experiments have been conducted on benchmark functions, a two-dimensional fractured reservoir and a three-dimensional enhanced geothermal system. The proposed algorithm outperforms other five state-of-the-art surrogate-assisted algorithms on all selected benchmark functions. The results on the two heat extraction cases also demonstrate that SLLES can achieve superior optimization performance compared with traditional evolutionary algorithm and other surrogate-assisted algorithms. This work lays a solid basis for efficient geothermal extraction of enhanced geothermal system and sheds light on the model management strategies of data-driven optimization in the areas of energy exploitation.

A modified metaheuristic algorithm for a home health care routing problem with health team skill levels

Home Health Care (HHC) services have emerged as a result of the need to provide care to patients/people who cannot be treated in hospital due to their special conditions and/or need home care. The care and treatment processes provided by this service have been appreciated by researchers as they can be less expensive and just as effective than care provided by a hospital or a skilled care facility. HHC gains importance due to the increasing epidemic disease cases, the increase in the elderly population, etc. In this study, it is aimed to provide high quality service as well as minimizing travel costs by considering the constraints related to travel balancing and type of transportation vehicle. So, environmental and economic factors could be included in the model. The proposed Home Health Care Routing Problem with Health Team Skill Level (HTSL-HHCRP) model was coded in GAMS 24.2.1 software. A new hybrid method named as Genetic Algorithm Simulated Annealing-Marine Predators Algorithm (GASA-MPA) has been developed to solve the large dimensions of the problem. In hybrid approach, SA has been used with an initial point obtained by GA. On the other hand, feasibility of the neighborhood solutions is guaranteed by solving a constraint satisfaction problem via MPA. Test problems’ performance was analyzed using the Relative Deviation Index (RDI) evaluation criteria. In addition, the sensitivity of the results according to some parameters selected by scenario analysis was examined. Results confirm the efficiency of the GASA-MPA algorithm in terms of time and objective function. Furthermore, by addressing skill levels of the healthcare team, it is shown that the proposed algorithm performs better than more traditional evolutionary algorithms in HHCRP. The comparisons show that the proposed method outperformed the classical methods not only in terms of best solution, but also the Gap (%) and RDI values.

Advances in teaching–learning-based optimization algorithm: A comprehensive survey(ICIC2022)

Teaching-learning-based optimization (TLBO) algorithm which imitates the teaching–learning process in a classroom, is one of population-based heuristic stochastic swarm intelligent algorithms. TLBO executes through similar iterative evolution processes as utilized by a standard evolutionary algorithm. Unlike traditional evolutionary algorithms and swarm intelligent algorithms, the iterative computation process of teaching–learning-based optimization is divided into two phases and each phase executes iterative learning operation. In this paper, we present a comprehensive survey on the recent advances in TLBO. A review of the current literature reveals intriguing challenges and suggests potential future research directions.

Multi-surrogate assisted PSO with adaptive speciation for expensive multimodal multi-objective optimization

Expensive multimodal multi-objective optimization problems (MMOPs) commonly arise in real-world situations, in which multiple Pareto solutions correspond to the same objective values. In order to provide satisfactory solutions for decision makers, plenty of evolutionary algorithms (EAs) have been used to solve MMOPs. However, the traditional EAs is limited in practice due to the time-consuming problem caused by a large number of fitness evaluations. To tackle this issue, a multi-surrogate assisted particle swarm optimization with adaptive speciation is proposed in this paper. In the proposed algorithm, a multi-surrogate model using adaptive scheduling strategy is introduced to reveal the many-to-one mapping relationship between decision space and objective space. To trade-off between convergence and diversity in both decision and objective space, a speciation method with adaptive niche radius is designed to perform species self-organization and evolution. Moreover, a surrogate assisted evolution with leader updating strategy is performed to guide the evolution of species. In order to verify the effectiveness of the proposed method, the benchmark problem (from IEEE Congress on evolutionary computation 2019) is analyzed experimentally. The experimental results show that the proposed method is superior to the state-of-the-art multimodal multi-objective evolutionary algorithm in term of maintaining the diversity of solutions in the decision and objective space.

Efficient Self-learning Evolutionary Neural Architecture Search

The evolutionary algorithm has become a major method for neural architecture search recently. However, the fixed probability distribution employed by the traditional evolutionary algorithm may lead to structural complexity and redundancy due to its inability to control the size of individual architectures, and it cannot learn from empirical information gathered during the search process to guide the subsequent search more effectively and efficiently. Moreover, evaluating the performance of all the searched architectures requires significant computing resources and time overhead. To overcome these challenges, we present the Efficient Self-learning Evolutionary Neural Architecture Search (ESE-NAS) method. Firstly, we propose an Adaptive Learning Strategy for Mutation Sampling, composed of a Model Size Control module and a Credit Assignment method for Mutation Candidates, to guide the search process by learning from the model size information and evaluation results of the architectures and adjusting the probability distributions for evolution sampling accordingly. Additionally, we developed a neural architecture performance predictor to further improve the efficiency of NAS. Experiments on CIFAR-10 and CIFAR-100 datasets show that ESE-NAS significantly brings forward the first hitting time of the optimal architectures and reaches a competitive performance level with classic manual-designed and NAS models while maintaining structural simplicity and efficiency.

Real-Time Collision Detection Optimization Algorithm Based on Snake Model in the Field of Big Data

Big data processing includes multiple processing flows of data. But data quality is the most important part of the entire process. Every data processing link will have an impact on the quality of big data. Collision detection is an important research content in many fields such as computer graphics and computer virtual reality. In layman's terms, it means that the computer detects the signal voltage on the channel while sending data. When the signal voltage swing value detected by a station exceeds a certain threshold value, it will be considered that at least two stations on the bus are sending data at the same time, indicating that a collision has occurred. As the number of questions increases, the level becomes higher, the target information becomes more diverse, and the algorithm becomes more complex. The traditional evolutionary algorithm is far from being able to deal with this situation effectively, and the optimization target algorithm emerges as the times require. Evolutionary computing is a mature global optimization method with high robustness and wide applicability. It has the characteristics of self-organization, self-adaptation, and self-learning. It is not limited by the nature of the problem and can effectively deal with complex problems that are difficult to solve by traditional optimization algorithms. This paper aims to study the optimization algorithm of real-time collision detection based on Snake model in the field of big data. It is expected that, with the support of big data technology, the efficiency of real-time collision detection of Snake model will be improved and time will be saved. This paper proposes a multiline swarm particle swarm algorithm and combines it with the Snake model to improve the detection efficiency of the collision detection algorithm. It verifies the detection performance of traditional algorithms and tests their effectiveness in detection. The experimental results of this paper show that the frame rate of the Snake model algorithm is 15, the frame rate of the K-DOPs algorithm is 6.7, and the error of the algorithm is 1.04. It shows that the frame rate of Snake model algorithm is better.