1,667 research outputs found

    Solving systems of nonlinear equations by harmony search

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    In this paper, we aim to analyze the performance of some variants of the harmony search (HS) metaheuristic when solving systems of nonlinear equations through the global optimization of an appropriate merit function. The HS metaheuristic draws its inspiration from an artistic process, the improvisation process of musicians seeking a wonderful harmony. A new differential best HS algorithm, based on an improvisation operator that mimics the best harmony and uses a differential variation, is proposed. Computational experiments involving a well-known set of small-dimensional problems are presented.Fundação para a Ciência e a Tecnologia (FCT

    Genetic Algorithm, Particle Swarm Optimization and Harmony Search:A quick comparison

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    Random Adjustment - Based Chaotic Metaheuristic Algorithms for Image Contrast Enhancement

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    Metaheuristic algorithm is a powerful optimization method, in which it can solve problemsby exploring the ordinarily large solution search space of these instances, that are believed tobe hard in general. However, the performances of these algorithms signicantly depend onthe setting of their parameter, while is not easy to set them accurately as well as completelyrelying on the problem\u27s characteristic. To ne-tune the parameters automatically, manymethods have been proposed to address this challenge, including fuzzy logic, chaos, randomadjustment and others. All of these methods for many years have been developed indepen-dently for automatic setting of metaheuristic parameters, and integration of two or more ofthese methods has not yet much conducted. Thus, a method that provides advantage fromcombining chaos and random adjustment is proposed. Some popular metaheuristic algo-rithms are used to test the performance of the proposed method, i.e. simulated annealing,particle swarm optimization, dierential evolution, and harmony search. As a case study ofthis research is contrast enhancement for images of Cameraman, Lena, Boat and Rice. Ingeneral, the simulation results show that the proposed methods are better than the originalmetaheuristic, chaotic metaheuristic, and metaheuristic by random adjustment

    An improved block matching algorithm for motion estimation invideo sequences and application in robotics

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    Block Matching is one of the most efficient techniques for motion estimation for video sequences. Metaheuristic algorithms have been used effectively for motion estimation. In this paper, we propose two hybrid algorithms: Artificial Bee Colony with Differential Evolution and Harmony Search with Differential Evolution based motion estimation algorithms. Extensive experiments are conducted using four standard video sequences. The video sequences utilized for experimentation have all essential features such as different formats, resolutions and number of frames which are generally required in input video sequences. We compare the performance of the proposed algorithms with other algorithms considering various parameters such as Structural Similarity, Peak Signal to Noise Ratio, Average Number of Search Points etc. The comparative results demonstrate that the proposed algorithms outperformed other algorithms

    Efficient intrusion detection scheme based on SVM

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    The network intrusion detection problem is the focus of current academic research. In this paper, we propose to use Support Vector Machine (SVM) model to identify and detect the network intrusion problem, and simultaneously introduce a new optimization search method, referred to as Improved Harmony Search (IHS) algorithm, to determine the parameters of the SVM model for better classification accuracy. Taking the general mechanism network system of a growing city in China between 2006 and 2012 as the sample, this study divides the mechanism into normal network system and crisis network system according to the harm extent of network intrusion. We consider a crisis network system coupled with two to three normal network systems as paired samples. Experimental results show that SVMs based on IHS have a high prediction accuracy which can perform prediction and classification of network intrusion detection and assist in guarding against network intrusion

    An improved block matching algorithm for motion estimation in video sequences and application in robotics

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    Block Matching is one of the most efficient techniques for motion estimation for video sequences. Metaheuristic algorithms have been used effectively for motion estimation. In this paper, we propose two hybrid algorithms: Artificial Bee Colony with Differential Evolution and Harmony Search with Differential Evolution based motion estimation algorithms. Extensive experiments are conducted using four standard video sequences. The video sequences utilized for experimentation have all essential features such as different formats, resolutions and number of frames which are generally required in input video sequences. We compare the performance of the proposed algorithms with other algorithms considering various parameters such as Structural Similarity, Peak Signal to Noise Ratio, Average Number of Search Points etc. The comparative results demonstrate that the proposed algorithms outperformed other algorithms

    Optimalna lokacija i parametri za FACT uređaj za kompenzaciju reaktivne snage koristeći algoritam harmonijskog pretraživanja

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    Reactive Power Compensation (RPC) is an important issue in the operation and control of power system. In this paper, two FACTS controller like Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) are considered for RPC. RPC is a multi-objective nonlinear optimization problem that minimizes the bus voltage deviation and real power loss. In this work, Harmony Search Algorithm (HSA) is used to determine the optimal location and setting of SVC and TCSC respectively. The efficacy of HSA is demonstrated on modified IEEE 30 bus power system for two operating conditions. A comparison of simulation results reveals the effectiveness of proposed algorithm over other well established population based optimization technique like Simple Genetic Algorithm (SGA),Particle Swarm Optimization (PSO) and Differential Evolution (DE).Kompenzacija reaktivne snage (RPC) važan je zadatak pri radu i upravljanju energetskim sustavima. U ovome radu razmatra se FACT regulator kao što su statički kompenzator (SVC) i tiristorski serijski kondenzator (TCSC). RPC je više kriterijski nelinearni optimizacijski problem gdje se minimizira odstupanje napona sabirnice i gubitci snage. Korišten je HSA algoritam (engl. Harmony Search Algorithm) za određivanje položaja i parametara SVC i TCSC. Efikasnost sustava demonstrirana je na modificiranom energetskom sustavu IEEE 30 za dva različita uvjeta. Usporedbna simulacijskih rezultata prikazuje efikasnost predloženog algoritma u odnosu na ostale metode kao što su genetski algoritmi (SGA), čestična optimizacija roja (PSO) i diferencijalna evolucija (DE)

    FIR Digital Filter and Neural Network Design using Harmony Search Algorithm

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    Harmony Search (HS) is an emerging metaheuristic algorithm inspired by the improvisation process of jazz musicians. In the HS algorithm, each musician (= decision variable) plays (= generates) a note (= a value) for finding the best harmony (= global optimum) all together. This algorithm has been employed to cope with numerous tasks in the past decade. In this thesis, HS algorithm has been applied to design digital filters of orders 24 and 48 as well as the parameters of neural network problems. Both multiobjective and single objective optimization techniques were applied to design FIR digital filters. 2-dimensional digital filters can be used for image processing and neural networks can be used for medical image diagnosis. Digital filter design using Harmony Search Algorithm can achieve results close to Parks McClellan Algorithm which shows that the algorithm is capable of solving complex engineering problems. Harmony Search is able to optimize the parameter values of feedforward network problems and fuzzy inference neural networks. The performance of a designed neural network was tested by introducing various noise levels at the testing inputs and the output of the neural networks with noise was compared to that without noise. It was observed that, even if noise is being introduced to the testing input there was not much difference in the output. Design results were obtained within a reasonable amount of time using Harmony Search Algorithm

    Improved Harmony Search Algorithm with Chaos for Absolute Value Equation

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     In this paper, an improved harmony search with chaos (HSCH) is presented for solving NP-hard absolute value equation (AVE) Ax - |x| = b, where A is an arbitrary square matrix whose singular values exceed one. The simulation results in solving some given AVE problems demonstrate that the HSCH algorithm is valid and outperforms the classical HS algorithm (HS) and HS algorithm with differential mutation operator (HSDE)

    Finding multiple roots of systems of nonlinear equations by a hybrid harmony search-based multistart method

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    A multistart (MS) clustering technique to compute multiple roots of a system of nonlinear equations through the global optimization of an appropriate merit function is presented. The search procedure that is invoked to converge to a root, starting from a randomly generated point inside the search space, is a new variant of the harmony search (HS) metaheuristic. The HS draws its inspiration from an artistic process, the improvisation process of musicians seeking a wonderful harmony. The new hybrid HS algorithm is based on an improvisation operator that mimics the best harmony and uses the idea of a differential variation, borrowed from the differential evolution algorithm. Computational experiments involving a benchmark set of small and large dimensional problems with multiple roots are presented. The results show that the proposed hybrid HS-based MS algorithm is effective in locating multiple roots and competitive when compared with other metaheuristics.FCT - Fuel Cell Technologies Program(UID/EMS/0615/2016). The authors are grateful to the anonymous referees for their helpful suggestions to improve the paper. This research has been supported by CIDEM (Centre for Research & Development in Mechanical Engineering, Portugal), by COMPETE POCI-01-0145-FEDER-007043 and FCT (Foundation for Science and Technology, Portugal) within the projects UID/EMS/0615/2016 and UID/CEC/00319/2013
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