This paper proposes a novel hybrid approach based on particle swarm optimization and local search, named PSOLS, for dynamic optimization problems. In the proposed approach, a swarm of particles with fuzzy social-only model is frequently applied to estimate the location of the peaks in the problem landscape. Upon convergence of the swarm to previously undetected positions in the search space, a ...

A model of the optical media with a spatially structured Kerr nonlinearity is introduced. The nonlinearity strength is modulated by a set of singular peaks on top of a self-focusing or defocusing uniform background. The peaks may include a repulsive or attractive linear potential too. We find that a pair of mutually symmetric peaks readily gives rise to the spontaneous symmetry breaking (SSB) o...

Dynamic environment problems require adaptive solution methodologies which can deal with the changes in the environment during the solution process for a given problem. A selection hyper-heuristic manages a set of low level heuristics (operators) and decides which one to apply at each iterative step. Recent studies show that selection hyperheuristic methodologies are indeed suitable for solving...

Due to dynamic and uncertain nature of many optimisation problems in real-world, the applied algorithm in this environment must be able to continuously track the changing optima over time. In this paper, we report a novel speciation-based firefly algorithm for dynamic optimisation, which improved its performance by employing prior landscape historical information. The proposed algorithm, namely...

Many real-world optimization problems are dynamic in nature. The applied algorithm in this environment can pose serious challenges, especially when the search space is multimodal with multiple, time-varying optima. To address these challenges, this paper investigates a speciation-based firefly algorithm to enhance the population diversity with aim of generating several populations in different ...

In many optimization problems in real world, objective function, design variable or constraints can be changed during time, so optimal value of these problems also can be changed. These kinds of problems are called dynamic. Algorithms which are designed for optimizing in these environments have some principles that distinguish them from algorithms designed in static environment. In this paper, ...

Depth and wavelength dependence of absorption and scattering coefficients at the South Pole AMANDA site were mapped with pulsed and D.C. light sources. The contribution of air bubbles to scattering decreases with depth and disappears at 1.4 km; at greater depths scattering by dust dominates. Peaks in scattering at several well-defined depths are attributed to peaks in dust concentration and are...

In most existing studies on dynamic multimodal optimization (DMMO), numerical simulations have been performed using the Moving Peaks Benchmark (MPB), which is a two-decade-old test suite that cannot simulate some critical aspects of DMMO problems. This study proposes Deterministic Distortion and Rotation (DDRB), method to generate deterministic problems can more diverse types challenges when co...

The main purposes of the present work are devoted to the investigation of the free axial vibration, as well as the time-dependent and forced axial vibration of a SWCNT subjected to a moving load. The governing equation is derived through using Hamilton's principle. Eringen’s nonlocal elasticity theory has been utilized to analyze the nonlocal behaviors of SWCNT. A Galerkin method based on a clo...

A new technique for motion estimation of moving objects ispresented. The analysis of the Hartley spectrum indicates that thevelocities of moving objects are related to the locations of the spectral peaks. The presented formulations and simulations demonstrate theapplicability of this technique. This method is simple, fast, and computationally efficient.