A Hybrid Max–Min Ant System by Levy Flight and Opposition-Based Learning

2021 ◽  
Author(s):  
Zhaojun Zhang ◽  
Zhaoxiong Xu ◽  
Shengyang Luan ◽  
Xuanyu Li
Keyword(s):  
Early Stage ◽  
Optimal Path ◽  
Search Time ◽  
Local Extremum ◽  
Upper And Lower Bounds ◽  
Lévy Flight ◽  
Ant System ◽  
Search Range ◽  
Levy Flight ◽  
Better Than

The max–min ant system (MMAS) is a modified ant colony optimization (ACO) algorithm. Its convergence speed is effectively improved by setting the upper and lower bounds of the pheromone and updating it in the optimal path. However, MMAS still has drawbacks, such as long search time and local extremums. In this paper, the hybrid max–min ant system (HMMAS) is proposed to deal with the shortcomings of MMAS. Employing Levy flight strategy, HMMAS can dynamically adjust the parameters to increase the diversity of solutions and expand the search range. Besides, HMMAS uses the OBL strategy to generate opposite solutions in the early stage. In this way, the convergence is accelerated. When HMMAS falls into a local extremum, the path reorganization strategy is utilized. With its help, HMMAS can redistribute the pheromone in each path and achieve global optimum. To verify the effectiveness, HMMAS is first compared with the three conventional ACO algorithms of AS, ACS, and MMAS in 20 sets of experiments. The results indicate that the average results of HMMAS in the 19 sets of TSP instances are better than the other three algorithms, and the standard deviation in the 14 sets of calculation instances is the smallest. Then, HMMAS is compared with some state-of-the-art algorithms, and the results show that HMMAS is better than other comparison algorithms, either by the minimum or the average value.

scholarly journals First exit time of a Lévy flight from a bounded region in ℝN

2015 ◽  
Vol 52 (3) ◽  
pp. 649-664 ◽  
Author(s):  
Yoora Kim ◽  
Irem Koprulu ◽  
Ness B. Shroff
Keyword(s):  
Exit Time ◽  
Length Distribution ◽  
Step Length ◽  
Upper And Lower Bounds ◽  
Bounded Region ◽  
Lévy Flight ◽  
First Exit Time ◽  
Levy Flight ◽  
Distribution Parameters ◽  
The Mean

In this paper we characterize the mean and the distribution of the first exit time of a Lévy flight from a bounded region inN-dimensional spaces. We characterize tight upper and lower bounds on the tail distribution of the first exit time, and provide the exact asymptotics of the mean first exit time for a given range of step-length distribution parameters.

scholarly journals First exit time of a Lévy flight from a bounded region in ℝN

2015 ◽  
Vol 52 (03) ◽  
pp. 649-664 ◽  
Author(s):  
Yoora Kim ◽  
Irem Koprulu ◽  
Ness B. Shroff
Keyword(s):  
Exit Time ◽  
Length Distribution ◽  
Step Length ◽  
Upper And Lower Bounds ◽  
Bounded Region ◽  
Lévy Flight ◽  
First Exit Time ◽  
Levy Flight ◽  
Distribution Parameters ◽  
The Mean

In this paper we characterize the mean and the distribution of the first exit time of a Lévy flight from a bounded region in N-dimensional spaces. We characterize tight upper and lower bounds on the tail distribution of the first exit time, and provide the exact asymptotics of the mean first exit time for a given range of step-length distribution parameters.

Feature Selection for Histopathological Image Classification using levy Flight Salp Swarm Optimizer

2019 ◽  
Vol 12 (4) ◽  
pp. 329-337 ◽  
Author(s):  
Venubabu Rachapudi ◽  
Golagani Lavanya Devi
Keyword(s):  
Feature Selection ◽  
Image Classification ◽  
Feature Selection Method ◽  
Selection Method ◽  
Lévy Flight ◽  
Levy Flight ◽  
Local Optima ◽  
Histopathological Image ◽  
Surf Features ◽  
Histopathological Image Classification

Background: An efficient feature selection method for Histopathological image classification plays an important role to eliminate irrelevant and redundant features. Therefore, this paper proposes a new levy flight salp swarm optimizer based feature selection method. Methods: The proposed levy flight salp swarm optimizer based feature selection method uses the levy flight steps for each follower salp to deviate them from local optima. The best solution returns the relevant and non-redundant features, which are fed to different classifiers for efficient and robust image classification. Results: The efficiency of the proposed levy flight salp swarm optimizer has been verified on 20 benchmark functions. The anticipated scheme beats the other considered meta-heuristic approaches. Furthermore, the anticipated feature selection method has shown better reduction in SURF features than other considered methods and performed well for histopathological image classification. Conclusion: This paper proposes an efficient levy flight salp Swarm Optimizer by modifying the step size of follower salp. The proposed modification reduces the chances of sticking into local optima. Furthermore, levy flight salp Swarm Optimizer has been utilized in the selection of optimum features from SURF features for the histopathological image classification. The simulation results validate that proposed method provides optimal values and high classification performance in comparison to other methods.

Salp swarm algorithm with crossover scheme and Lévy flight for global optimization

2021 ◽  
pp. 1-12
Author(s):  
Heming Jia ◽  
Chunbo Lang
Keyword(s):  
Global Optimization ◽  
Heuristic Algorithm ◽  
Experimental Results ◽  
High Dimensional ◽  
Lévy Flight ◽  
Test Functions ◽  
Levy Flight ◽  
Salp Swarm Algorithm ◽  
Swarm Algorithm ◽  
Accuracy And Stability

Salp swarm algorithm (SSA) is a meta-heuristic algorithm proposed in recent years, which shows certain advantages in solving some optimization tasks. However, with the increasing difficulty of solving the problem (e.g. multi-modal, high-dimensional), the convergence accuracy and stability of SSA algorithm decrease. In order to overcome the drawbacks, salp swarm algorithm with crossover scheme and Lévy flight (SSACL) is proposed. The crossover scheme and Lévy flight strategy are used to improve the movement patterns of salp leader and followers, respectively. Experiments have been conducted on various test functions, including unimodal, multimodal, and composite functions. The experimental results indicate that the proposed SSACL algorithm outperforms other advanced algorithms in terms of precision, stability, and efficiency. Furthermore, the Wilcoxon’s rank sum test illustrates the advantages of proposed method in a statistical and meaningful way.

Optimal placement of distributed generation based on DISCO’s additional benefit using self adaptive levy flight based black widow optimization

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Naga Lakshmi Gubbala Venkata ◽  
Jaya Laxmi Askani ◽  
Venkataramana Veeramsetty
Keyword(s):  
Distributed Generation ◽  
Distribution Network ◽  
Additional Benefit ◽  
Operating Conditions ◽  
Optimal Placement ◽  
Lévy Flight ◽  
Black Widow ◽  
Levy Flight ◽  
Simulation Performance ◽  
Self Adaptive

Abstract Optimal placement of Distributed Generation (DG) is a crucial challenge for Distribution Companies (DISCO’s) to run the distribution network in good operating conditions. Optimal positioning of DG units is an optimization issue where maximization of DISCO’s additional benefit due to the installation of DG units in the network is considered to be an objective function. In this article, the self adaptive levy flight based black widow optimization algorithm is used as an optimization strategy to find the optimum position and size of the DG units. The proposed algorithm is implemented in the IEEE 15 and PG & E 69 bus management systems in the MATLAB environment. Based on the simulation performance, it has been found that with the correct location and size of the DG modules, the distribution network can be run with maximum DISCO’s additional benefit.

scholarly journals Modified Levy Flight Optimization for a Maximum Power Point Tracking Algorithm under Partial Shading

2021 ◽  
Vol 11 (3) ◽  
pp. 992
Author(s):  
Chanuri Charin ◽  
Dahaman Ishak ◽  
Muhammad Ammirrul Atiqi Mohd Zainuri ◽  
Baharuddin Ismail
Keyword(s):  
High Efficiency ◽  
Energy System ◽  
Fast Response ◽  
Lévy Flight ◽  
Partial Shading ◽  
Levy Flight ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Steady State Oscillation ◽  
Power Point

This paper presents a novel modified Levy flight optimization for a photovoltaic PV solar energy system. Conventionally, the Perturb and Observe (P&O) algorithm has been widely deployed in most applications due to its simplicity and ease of implementation. However, P&O suffers from steady-state oscillation and stability, besides its failure in tracking the optimum power under partial shading conditions and fast irradiance changes. Therefore, a modified Levy flight optimization is proposed by incorporating a global search of beta parameters, which can significantly improve the tracking capability in local and global searches compared to the conventional methods. The proposed modified Levy flight optimization is verified with simulations and experiments under uniform, non-uniform, and dynamic conditions. All results prove the advantages of the proposed modified Levy flight optimization in extracting the optimal power with a fast response and high efficiency from the PV arrays.

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