9,987 research outputs found

    Ant-Fuzzy Meta Heuristic Genetic Sensor Network System for Multi Sink Aggregated Data Transmission

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    Wireless sensor network with the hierarchical organization of sensors aggregate the tasks into groups. The sensor nodes broadcast the aggregated data directly to the distant base station. Existing Mixed Integer Programming (MIP) formulation obtain the good solutions for multi-action processes but not effectual in developing the hybrid genetic algorithms with the Tabu search meta-heuristics ant colony optimization. Another existing work developed for security purpose named as Dynamic secure end-to-end Data Aggregation with Privacy function (DyDAP) decrease the network load but topological configurations with multiple sinks are not addressed. To develop the hybrid genetic algorithm on ant-fuzzy system, Hybrid (i.e.,) ant-fuzzy Meta-heuristic Genetic method (HMG) based on the Tabu search is proposed in this paper. Ant-fuzzy Meta heuristic Genetic method carries out the classification process on the aggregated data. The classification based on the genetic method uses the Tabu search based mathematical operation to attain the feasible solution on multiple sinks. Initially, Ant-fuzzy Meta-heuristic Genetic method classifies the data record based on the weighted meta-heuristic distance. The classified records perform the Tabu search operation to transmit the aggregated data to the multiple sink nodes. HMG method achieves approximately 19 % improved transmitted message rate. Experiment is conducted in the network simulator on the factor such as classification time and transmission rate

    3D Protein structure prediction with genetic tabu search algorithm

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    Abstract Background Protein structure prediction (PSP) has important applications in different fields, such as drug design, disease prediction, and so on. In protein structure prediction, there are two important issues. The first one is the design of the structure model and the second one is the design of the optimization technology. Because of the complexity of the realistic protein structure, the structure model adopted in this paper is a simplified model, which is called off-lattice AB model. After the structure model is assumed, optimization technology is needed for searching the best conformation of a protein sequence based on the assumed structure model. However, PSP is an NP-hard problem even if the simplest model is assumed. Thus, many algorithms have been developed to solve the global optimization problem. In this paper, a hybrid algorithm, which combines genetic algorithm (GA) and tabu search (TS) algorithm, is developed to complete this task. Results In order to develop an efficient optimization algorithm, several improved strategies are developed for the proposed genetic tabu search algorithm. The combined use of these strategies can improve the efficiency of the algorithm. In these strategies, tabu search introduced into the crossover and mutation operators can improve the local search capability, the adoption of variable population size strategy can maintain the diversity of the population, and the ranking selection strategy can improve the possibility of an individual with low energy value entering into next generation. Experiments are performed with Fibonacci sequences and real protein sequences. Experimental results show that the lowest energy obtained by the proposed GATS algorithm is lower than that obtained by previous methods. Conclusions The hybrid algorithm has the advantages from both genetic algorithm and tabu search algorithm. It makes use of the advantage of multiple search points in genetic algorithm, and can overcome poor hill-climbing capability in the conventional genetic algorithm by using the flexible memory functions of TS. Compared with some previous algorithms, GATS algorithm has better performance in global optimization and can predict 3D protein structure more effectively

    Adaptive approach heuristics for the generalized assignment problem

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    The Generalized Assignment Problem consists in assigning a set of tasks to a set of agents with minimum cost. Each agent has a limited amount of a single resource and each task must be assigned to one and only one agent, requiring a certain amount of the resource of the agent. We present new metaheuristics for the generalized assignment problem based on hybrid approaches. One metaheuristic is a MAX-MIN Ant System (MMAS), an improved version of the Ant System, which was recently proposed by Stutzle and Hoos to combinatorial optimization problems, and it can be seen has an adaptive sampling algorithm that takes in consideration the experience gathered in earlier iterations of the algorithm. Moreover, the latter heuristic is combined with local search and tabu search heuristics to improve the search. A greedy randomized adaptive search heuristic (GRASP) is also proposed. Several neighborhoods are studied, including one based on ejection chains that produces good moves without increasing the computational effort. We present computational results of the comparative performance, followed by concluding remarks and ideas on future research in generalized assignment related problems.Metaheuristics, generalized assignment, local search, GRASP, tabu search, ant systems

    An improved hybrid optimization algorithm for the quadratic assignment problem

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    In this paper, we present an improved hybrid optimization algorithm, which was applied to the hard combinatorial optimization problem, the quadratic assignment problem (QAP). This is an extended version of the earlier hybrid heuristic approach proposed by the author. The new algorithm is distinguished for the further exploitation of the idea of hybridization of the wellā€known efficient heuristic algorithms, namely, simulated annealing (SA) and tabu search (TS). The important feature of our algorithm is the soā€called ā€œcold restart mechanismā€, which is used in order to avoid a possible ā€œstagnationā€ of the search. This strategy resulted in very good solutions obtained during simulations with a number of the QAP instances (test data). These solutions show that the proposed algorithm outperforms both the ā€œpureā€ SA/TS algorithms and the earlier author's combined SA and TS algorithm. Key words: hybrid optimization, simulated annealing, tabu search, quadratic assignment problem, simulation Patobulintas hibridinis optimizavimo algoritmas kvadratinio paskirstymo uždaviniui Santrauka Å iame straipsnyje pasi ulytas patobulintas hibridinis euristinis optimizavimo algoritmas gerai žinomam, sudetingam kombinatorinio optimizavimo uždaviniui, b utent, kvadratinio paskirstymo (KP) uždaviniui. Taiā€pagerinta autoriaus ankstesnio hibridinio algoritmo versija. Naujasis algoritmas pasižymi tuo, jog čia iÅ”pletota efektyviu euristiku (atkaitinimo modeliavimo (AM) (angi. simulated annealing) ir tabu paieÅ”kos (TP) (angi. tabu search) ā€œhibridizacijosā€ ideja. ā€œHibridizacijaā€ remiasi vadinamaja iteracine schema: TP algoritmas panaudojamas kaip postā€analizes proced ura AM algoritmo gautajam sprendiniui, savo ruožtu, AM algoritmas taikomas sprendiniu sekai, gautai sprendiniu diversifikavimo/generavimo keliu. Svarbi pasi ulyto algoritmo savybe yra ir ta, kad jame realizuotas vadinamasis ā€œÅ”altojo pakartotinio startoā€ principas, kurio paskirtis padeti iÅ”vengti galimu paieÅ”kos ā€œstagnacijosā€ situaciju. Naujasis algoritmas iÅ”bandytas su KP uždavinio duomenimis iÅ” testiniu pavyzdžiu bibliotekos QAPLIB. Gauti eksperimentu rezultatai liudija, jog nagrinetiems KP uždavinio pavyzdžiams si ulomas algoritmas yra pranaÅ”esnis už ankstesnius atkaitinimo modeliavimo ir tabu paieÅ”kos algoritmus, taip pat už ankstesni autoriaus hibridini algoritma. First Published Online: 14 Oct 201
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