We present an inverse scattering problem for recovering the shapes of multiple conducting cylinders with the immersed targets in a half-space by the geneticalgorithm. Two separate perfect-conducting cylinders of unkn...
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We present an inverse scattering problem for recovering the shapes of multiple conducting cylinders with the immersed targets in a half-space by the geneticalgorithm. Two separate perfect-conducting cylinders of unknown shapes are buried in one half-space and illuminated by a transverse magnetic plane wave from the other half-space. In the shape expansions, the cubic-spline method is utilized to describe the shapes of objects. Based on the boundary condition and the measured scattered field, we have derived a set of nonlinear integral equations, and the inverse scattering problem is reformulated into an optimization problem. The improved steady-state genetic algorithm is used to solve the global extreme solution. Here, frequency dependence on the inverse problem of buried multiple conductors is investigated. Numerical results show that the reconstruction is good in the resonant frequency range, even when the initial guesses are far different from the original shapes. On the contrary, if the frequency is too high or too low, the reconstruction becomes bad. In addition, the reconstructed errors for different distances between two conductors are investigated. It is found the reconstructed results are poor when the distance between two conductors is less than about a wavelength.
This article presents a computational approach to the imaging of a perfectly conducting cylinder buried in a slab. A conducting cylinder of unknown shape buried in a slab scatters the incident wave from outside. The s...
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This article presents a computational approach to the imaging of a perfectly conducting cylinder buried in a slab. A conducting cylinder of unknown shape buried in a slab scatters the incident wave from outside. The scattered field is recorded outside the slab. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived, and the imaging problem is reformulated into an optimization problem. The geneticalgorithm is then employed to determine global extreme solution of the cost function. Numerical results demonstrated that, even when the initial guess is far removed from the exact one, good reconstruction can be obtained. In such a case, the gradient-based methods often are trapped in a local extreme. In addition, the effect of Gaussian noise on the reconstruction is investigated. (C) 2004 Wiley Periodicals, Inc.
With the advance of automation technology,the scale of industrial communication networks at field level is *** real-time performance of these networks is therefore becoming an increasingly difficult *** paper addresse...
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With the advance of automation technology,the scale of industrial communication networks at field level is *** real-time performance of these networks is therefore becoming an increasingly difficult *** paper addresses the optimization of device allocation in industrial Ethernet networks with real-time constraints (DAIEN-RC).Considering the inherent diversity of real-time requirements of typical industrial applications,a novel optimization criterion based on relative delay is proposed.A hybrid geneticalgorithm incorporating a reduced variable neighborhood search (GA-rVNS) is developed for *** results show that the proposed novel scheme achieves a superior performance compared to existing schemes,especially for large scale industrial networks.
In this paper, we investigate the imaging problem to determine both the shape and the conductivity of a partially immersed non-uniform conducting cylinder from the knowledge of scattered far-field pattern of TM waves ...
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In this paper, we investigate the imaging problem to determine both the shape and the conductivity of a partially immersed non-uniform conducting cylinder from the knowledge of scattered far-field pattern of TM waves by solving the ill-posed nonlinear equation. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the inverse problem is reformulated into an optimization one. The steady-state genetic algorithm is then employed to find out the global extreme solution of the object function. As a result, the shape and the conductivity of the conductor can be obtained. Numerical results are given to demonstrate that even in the presence of noise, good reconstruction can be obtained.
In this paper we propose a novel waypoint-based robot navigation method that combines reactive and deliberative actions. The approach uses reactive exploration to generate waypoints that can then be used by a delibera...
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In this paper we propose a novel waypoint-based robot navigation method that combines reactive and deliberative actions. The approach uses reactive exploration to generate waypoints that can then be used by a deliberative system to plan future movements through the same environment. The waypoints are used largely to provide the interface between reactive and deliberative navigation and a range of methods could be used for either type of navigation. In the current work, an incremental decision tree method is used to navigate the robot reactively from the specified initial position to its destination avoiding obstacles in its path and a geneticalgorithm method is used to perform the deliberative navigation. The new method is shown to have a number of practical advantages. Firstly, in contrast with many deliberative approaches, complete knowledge of the environment is not required, nor is it necessary to make assumptions regarding the geometry of obstacles. Secondly, the presence of a reactive navigator means it is always possible to continue directed movements in unknown or changing environments or when time constraints become particularly demanding. Thirdly, the use of waypoints allows escape from certain obstacle configurations that would normally trap robots navigated under the control of purely reactive methods. In addition, the results presented in this paper from a number of realistic simulated environments show that the adoption of waypoints significantly reduces the time to calculate a deliberative path.
A novel memetic algorithm (MA) for the design of vector quantizers (VQs) is presented in this paper. The algorithm uses steady-state genetic algorithm (GA) for the global search and K-means algorithm for the local imp...
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A novel memetic algorithm (MA) for the design of vector quantizers (VQs) is presented in this paper. The algorithm uses steady-state genetic algorithm (GA) for the global search and K-means algorithm for the local improvement. As compared with the usual MA using the generational GA for global search, the proposed MA dramatically reduces the computational time for VQ training. In addition, it attains a near global optimal solution, and its performance is insensitive to the selection of initial codewords. Numerical results show that it can save more than 70% of computation time while maintaining a comparable performance as previous MA.
This article presents a computational approach to the image reconstruction of a perfectly conducting cylinder illuminated by transverse electric waves. A perfectly conducting cylinder of unknown shape buried in one ha...
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This article presents a computational approach to the image reconstruction of a perfectly conducting cylinder illuminated by transverse electric waves. A perfectly conducting cylinder of unknown shape buried in one half-space and scatters the incident wave from another half-space where the scattered field is recorded. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived, and the imaging problem is reformulated into an optimization problem. The steadystategeneticalgorithm is then employed to find out the global extreme solution of the cost function. Numerical results demonstrated that, even when the initial guess is far away from the exact one, good reconstruction can be obtained. In such a case, the gradient-based methods often get trapped in a local extreme. In addition, the effect of different noise on the reconstruction is investigated. (C) 2006 Wiley Periodicals, Inc.
Given an undirected graph with weights associated with its vertices, the minimum weight vertex cover problem seeks a subset of vertices with minimum sum of weights such that each edge of the graph has at least one end...
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Given an undirected graph with weights associated with its vertices, the minimum weight vertex cover problem seeks a subset of vertices with minimum sum of weights such that each edge of the graph has at least one endpoint belonging to the subset. In this paper, we propose a hybrid approach, combining a steady-state genetic algorithm and a greedy heuristic, for the minimum weight vertex cover problem. The geneticalgorithm generates vertex cover, which is then reduced to minimal weight vertex cover by the heuristic. We have evaluated the performance of our algorithm on several test problems of varying sizes. Computational results show the effectiveness of our approach in solving the minimum weight vertex cover problem.
This paper presents two hybrid metaheuristic approaches, viz. a hybrid steady-state genetic algorithm (SSGA) and a hybrid evolutionary algorithm with guided mutation (EA/G) for order acceptance and scheduling (OAS) pr...
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This paper presents two hybrid metaheuristic approaches, viz. a hybrid steady-state genetic algorithm (SSGA) and a hybrid evolutionary algorithm with guided mutation (EA/G) for order acceptance and scheduling (OAS) problem in a single machine environment where orders are supposed to have release dates and sequence dependent setup times are incurred in switching from one order to next in the schedule. OAS problem is an NP-hard problem. We have compared our approaches with the state-of-the-art approaches reported in the literature. Computational results show the effectiveness of our approaches. (C) 2016 Elsevier B.V. All rights reserved.
This paper presents a new hybrid approach (NSGGA) combining steady-state grouping geneticalgorithm with a local search for the maximally diverse grouping problem (MDGP) related to equal group-size. The MDGP is a well...
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This paper presents a new hybrid approach (NSGGA) combining steady-state grouping geneticalgorithm with a local search for the maximally diverse grouping problem (MDGP) related to equal group-size. The MDGP is a well-known NP-Hard combinatorial optimization problem and finds numerous applications in real world. NSGGA employs particularly (a) crossover operator (b) the effective way of utilization of local search and (c) the additional replacement strategy, making it different from the existing geneticalgorithm for the MDGP. On a set of large benchmark instances, NSGGA is competitive in comparison to the existing best-known approaches in the literature and performs particularly well on large-size instances. Some important ingredients of NSGGA that shed some light on the adequacy of NSGGA are analyzed.
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