Parallel physical optimization algorithms for allocating data to multicomputer nodes

Three parallel physical optimization algorithms for allocating irregular data to multicomputer nodes are presented. They are based on simulated annealing, neural networks and genetic algorithms. All three algorithms deviate from the sequential versions in order to achieve acceptable speedups. The parallel simulated annealing (PSA) and neural network (PNN) algorithms include communication schemes that are adapted to the properties of the allocation problem and of the algorithms themselves for maintaining both good solutions and reasonable execution times. The parallel genetic algorithm (PGA) is based on a natural model of evolution. The performances of these algorithms are evaluated and compared. The three parallel algorithms maintain the good solution qualities of their sequential counterparts. Their comparison shows their suitability for different applications. For example, PGA yields the best solutions, but it is the slowest of the three. PNN is the fastest, but it yields lower quality solutions. PSA's performance lies in the middle.     

Performance comparison of bio-inspired optimization algorithms for Sierpinski gasket fractal antenna design

The Sierpinski gasket fractal antenna is most popular structure in the domain of fractal antennas. This fractal antenna has multi-band performance, and hence, the design of this antenna for the desired frequencies is a challenging problem. The artificial intelligence tools like artificial neural networks, fuzzy logic systems, bio-inspired optimization techniques are appropriate to provide accurate design solution in such cases. In this paper, three most popular bio-inspired optimization algorithms: genetic algorithms, particle swarm optimization (PSO), and bacterial foraging optimization, have been proposed to solve the design issues of Sierpinski gasket pre-fractal antenna. Their performances are analyzed and are compared with the experimental results. A simplified expression for calculation of resonant frequency of Sierpinski gasket pre-fractal antenna is proposed and is used as the objective function. Finally, the effectiveness is compared on the basis of three different measures: mean absolute percentage error, the average time taken by the models to evaluate the results, and the coefficient of correlation. The results indicate that the PSO algorithm is most suitable for this type of antenna.     

Intelligent computing for numerical treatment of nonlinear prey–predator models

In this study, a new computing paradigm is presented for evaluation of dynamics of nonlinear prey–predator mathematical model by exploiting the strengths of integrated intelligent mechanism through artificial neural networks, genetic algorithms and interior-point algorithm. In the scheme, artificial neural network based differential equation models of the system are constructed and optimization of the networks is performed with effective global search ability of genetic algorithm and its hybridization with interior-point algorithm for rapid local search. The proposed technique is applied to variants of nonlinear prey–predator models by taking different rating factors and comparison with Adams numerical solver certify the correctness for each scenario. The statistical studies have been conducted to authenticate the accuracy and convergence of the design methodology in terms of mean absolute error, root mean squared error and Nash-Sutcliffe efficiency performance indices.     

Multi-objective evolutionary algorithm using problem-specific genetic operators for community detection in networks

Automatic network clustering is an important method for mining the meaningful communities of complex networks. Uncovered communities help to understand the potential system structure and functionality. Many algorithms that use multiple optimization criteria and optimize a population of solutions are difficult to apply to real systems because they suffer a long optimization process. In this paper, in order to accelerate the optimization process and to uncover multiple significant community structures more effectively, a multi-objective evolutionary algorithm is proposed and evaluated using problem-specific genetic mutation and group crossover, and problem-specific initialization. Since crossover operators mainly contribute to performance of genetic algorithms, more problem-specific group crossover operators are introduced and evaluated for intelligent evolution of population. The experiments on both artificial and real-world networks demonstrate that the proposed evolutionary algorithm with problem-specific genetic operations has effective performance on discovering the community structure of networks.

     

A hybrid approach based on stochastic competitive Hopfield neural network and efficient genetic algorithm for frequency assignment problem

This paper presents a hybrid efficient genetic algorithm (EGA) for the stochastic competitive Hopfield (SCH) neural network, which is named SCH–EGA. This approach aims to tackle the frequency assignment problem (FAP). The objective of the FAP in satellite communication system is to minimize the co-channel interference between satellite communication systems by rearranging the frequency assignment so that they can accommodate increasing demands. Our hybrid algorithm involves a stochastic competitive Hopfield neural network (SCHNN) which manages the problem constraints, when a genetic algorithm searches for high quality solutions with the minimum possible cost. Our hybrid algorithm, reflecting a special type of algorithm hybrid thought, owns good adaptability which cannot only deal with the FAP, but also cope with other problems including the clustering, classification, and the maximum clique problem, etc. In this paper, we first propose five optimal strategies to build an efficient genetic algorithm. Then we explore three hybridizations between SCHNN and EGA to discover the best hybrid algorithm. We believe that the comparison can also be helpful for hybridizations between neural networks and other evolutionary algorithms such as the particle swarm optimization algorithm, the artificial bee colony algorithm, etc. In the experiments, our hybrid algorithm obtains better or comparable performance than other algorithms on 5 benchmark problems and 12 large problems randomly generated. Finally, we show that our hybrid algorithm can obtain good results with a small size population.     

基于Metropolis遗传算法的并联机器人结构优化设计

以六自由度Stewart并联机器人的灵巧度为目标函数，以设计空间、每条支腿的最大最小长度之比和虎克铰、球铰的极限摆角为约束条件建立了结构优化模型．将模拟退火算法中的Metropolis准则引入到实值编码遗传算法的选择操作中，产生了Metropolis遗传算法，采用该算法进行了并联机器人结构优化问题的求解．通过与采用标准遗传算法得出的结果比较，证实了Metropolis遗传算法在并联机器人结构优化设计中的有效性和优越性．     

Fractional-Neuro-Optimizer: A Neural-Network-Based Optimization Method

Up to now, there have been many attempts in the use of artificial neural networks (ANNs) for solving optimization problems and some types of ANNs, such as Hopfield network and Boltzmann machine, have been applied for combinatorial optimization problems. However, there are some restrictions in the use of ANNs as optimizers. For example: (1) ANNs cannot optimize continuous variable problems; (2) discrete problems should be mapped into the neural networks’ architecture; and (3) most of the existing neural networks are applicable only for a class of smooth optimization problems and global convexity conditions on the objective functions and constraints are required. In this paper, we introduce a new procedure for stochastic optimization by a recurrent ANN. The concept of fractional calculus is adopted to propose a novel weight updating rule. The introduced method is called fractional-neuro-optimizer (FNO). This method starts with an initial solution and adjusts the network’s weights by a new heuristic and unsupervised rule to reach a good solution. The efficiency of FNO is compared to the genetic algorithm and particle swarm optimization techniques. Finally, the proposed FNO is used for determining the parameters of a proportional–integral–derivative controller for an automatic voltage regulator power system and is applied for designing the water distribution networks.     

A novel approach to the placement and routing problems for field programmable gate arrays

This paper presents an artificial neural network (ANN) based parallel evolutionary solution to the placement and routing problems for field programmable gate arrays (FPGAs). The concepts of artificial neural networks are utilized for guiding the parallel genetic algorithm to intelligently transform a set of initial populations of randomly generated solutions to a final set of populations that contain solutions approximating the optimal one. The fundamental concept of this paper lies in capturing the various intuitive strategies of the human brain into neural networks, which may help the genetic algorithm to evolve its population in a more lucrative manner. A carefully chosen fitness function acts in the capacity of a yardstick to appraise the quality of each “chromosome” to aid the selection phase. In conjunction with the migration phase and the chosen fitness function various genetic operators are employed, to expedite the transformation of the initial population towards the final solution. The suggested algorithms have been implemented on a 12-node SGI Origin-2000 platform using the message passing interface (MPI) standard and the neural network utilities provided by MAT Lab software. The results obtained by executing the same are extremely encouraging, especially for circuits with very large number of nets.     

Bio inspired computing – A review of algorithms and scope of applications

With the explosion of data generation, getting optimal solutions to data driven problems is increasingly becoming a challenge, if not impossible. It is increasingly being recognised that applications of intelligent bio-inspired algorithms are necessary for addressing highly complex problems to provide working solutions in time, especially with dynamic problem definitions, fluctuations in constraints, incomplete or imperfect information and limited computation capacity. More and more such intelligent algorithms are thus being explored for solving different complex problems. While some studies are exploring the application of these algorithms in a novel context, other studies are incrementally improving the algorithm itself. However, the fast growth in the domain makes researchers unaware of the progresses across different approaches and hence awareness across algorithms is increasingly reducing, due to which the literature on bio-inspired computing is skewed towards few algorithms only (like neural networks, genetic algorithms, particle swarm and ant colony optimization). To address this concern, we identify the popularly used algorithms within the domain of bio-inspired algorithms and discuss their principles, developments and scope of application. Specifically, we have discussed the neural networks, genetic algorithm, particle swarm, ant colony optimization, artificial bee colony, bacterial foraging, cuckoo search, firefly, leaping frog, bat algorithm, flower pollination and artificial plant optimization algorithm. Further objectives which could be addressed by these twelve algorithms have also be identified and discussed. This review would pave the path for future studies to choose algorithms based on fitment. We have also identified other bio-inspired algorithms, where there are a lot of scope in theory development and applications, due to the absence of significant literature.     

人工神经网络的并行分布处理

神经元的映射分配是人工神经网络虚拟实现中的重要研究课题。本文系统地分析了人工神经网络的重要性质－并行分布处理，并对映射分配问题中的两个关键性概念－负载均衡和通信开销进行了深入讨论。以此为基础，提出了一系列映射算法，并对算法性能进行了分析。其中，吸收算法最大程度地开发了人工神经网络固有的并行性，是一个实时的算法。     

基于局部进化的Hopfield神经网络的优化计算方法

提出一种基于局部进化的Hopfield神经网络优化计算方法，该方法将遗传算法和Hopfield神经网络结合在一起，克服了Hopfield神经网络易收敛到局部最优值的缺点，以及遗传算法收敛速度慢的缺点。该方法首先由Hopfield神经网络进行状态方程的迭代计算降低网络能量，收敛后的Hopfield神经网络在局部范围内进行遗传算法寻优，以跳出可能的局部最优值陷阱，再由Hopfield神经网络进一步迭代优化。这种局部进化的Hopfield神经网络优化计算方法尤其适合于大规模的优化问题，对图像分割问题和规模较大的200城市旅行商问题的优化计算结果表明，其全局收敛率和收敛速度明显提高。     

Bio-inspired and gradient-based algorithms to train MLPs: The influence of diversity

This paper has three main goals: (i) to employ two classes of algorithms: bio-inspired and gradient-based to train multi-layer perceptron (MLP) neural networks for pattern classification; (ii) to combine the trained neural networks into ensembles of classifiers; and (iii) to investigate the influence of diversity in the classification performance of individual and ensembles of classifiers. The optimization version of an artificial immune network, named opt-aiNet, particle swarm optimization (PSO) and an evolutionary algorithm (EA) are used as bio-inspired methods to train MLP networks. Besides, the standard backpropagation with momentum (BPM), a quasi-Newton method called DFP and a modified scaled-conjugate gradient (SCGM) are the gradient-based algorithms used to train MLP networks in this work. Comparisons among all the training methods are presented in terms of classification accuracy and diversity of the solutions found. The results obtained suggest that most bio-inspired algorithms deteriorate the diversity of solutions during the search, while immune-based methods, like opt-aiNet, and multiple initializations of standard gradient-based algorithms provide diverse solutions that result in good classification accuracy for the ensembles.     

A neuro-genetic-simulated annealing approach to the inverse kinematics solution of robots: a simulation based study

In this study, a hybrid intelligent solution system including neural networks, genetic algorithms and simulated annealing has been proposed for the inverse kinematics solution of robotic manipulators. The main purpose of the proposed system is to decrease the end effector error of a neural network based inverse kinematics solution. In the designed hybrid intelligent system, simulated annealing algorithm has been used as a genetic operator to decrease the process time of the genetic algorithm to find the optimum solution. Obtained best solution from the neural network has been included in the initial solution of genetic algorithm with randomly produced solutions. The end effector error has been reduced micrometer levels after the implementation of the hybrid intelligent solution system.     

并行遗传算法与神经网络,模糊系统的结合

遗传算法是模拟自然界生物进化过程的计算模型。本文介绍了并行遗传算法的不同分类及不同并行策略，又将遗传算法分别与神经网络、模糊系统结合起来进行并行处理，并在曙光１０００系统上实现。算法分析表明，并行遗传算法可以有效地提高收敛速度。     

Cooperative binary-real coded genetic algorithms for generating and adapting artificial neural networks

This paper describes a genetic system for designing and training feed-forward artificial neural networks to solve any problem presented as a set of training patterns. This system, called GANN, employs two interconnected genetic algorithms that work parallelly to design and train the better neural network that solves the problem. Designing neural architectures is performed by a genetic algorithm that uses a new indirect binary codification of the neural connections based on an algebraic structure defined in the set of all possible architectures that could solve the problem. A crossover operation, known as Hamming crossover, has been designed to obtain better performance when working with this type of codification. Training neural networks is also accomplished by genetic algorithms but, this time, real number codification is employed. To do so, morphological crossover operation has been developed inspired on the mathematical morphology theory. Experimental results are reported from the application of GANN to the breast cancer diagnosis within a complete computer-aided diagnosis system.     

遗传算法在人工神经网络中的应用综述

本文介绍正被逐渐广泛应用的新型的、随机性的全局优化方法－遗传算法,系统地讨论了遗传算法在人工神经网络中的主要应用,实验结果显示了遗传算法快速学习网络权重的能力,并且能够摆脱局部极小点的困扰。     

动态环拓扑多机系统上DBP学习算法并行计算模型的构造与实现

人工神经网络模型的软件模拟，其并行算法的设计、实现及性能评价对于神经网络计算机和各种专用神经网络ＶＬＳＩ芯片的研制具有十分重要的意义．本文首先构造了一个分布式存储器、信息传递方式的多机系统作为软件模拟人工神经网络的平台，并用一个环拓扑结构的多Ｔｒａｎｓｐｕｔｅｒ网络予以实现．接着提出并实现了一个适用于动态环拓扑形式的ＤＢＰ并行计算模型，它主要包括神经元的划分和映射策略；ＤＢＰ中活性值、误差反向传播及权值修改的多机并行算法．然后讨论该ＤＢＰ算法的时间复杂度和加速比．     

A parallel evolving algorithm for flexible neural tree

In the past few decades, much success has been achieved in the use of artificial neural networks for classification, recognition, approximation and control. Flexible neural tree (FNT) is a special kind of artificial neural network with flexible tree structures. The most distinctive feature of FNT is its flexible tree structures. This makes it possible for FNT to obtain near-optimal network structures using tree structure optimization algorithms. But the modeling efficiency of FNT is always a problem due to its two-stage optimization. This paper designed a parallel evolving algorithm for FNT (PE-FNT). This algorithm uses PIPE algorithm to optimize tree structures and PSO algorithm to optimize parameters. The evaluation processes of tree structure populations and parameter populations were both parallelized. As an implementation of PE-FNT algorithm, two parallel programs were developed using MPI. A small data set, two medium data sets and three large data sets were applied for the performance evaluations of these programs. Experimental results show that PE-FNT algorithm is an effective parallel FNT algorithm especially for large data sets.     

An Algebraic Model for Generating and Adapting Neural Networks by Means of Optimization Methods

This paper describes a new scheme of binary codification of artificial neural networks designed to generate automatically neural networks using any optimization method. Instead of using direct mapping of strings of bits in network connectivities, this particular codification abstracts binary encoding so that it does not reference the artificial indexing of network nodes; this codification employs shorter string length and avoids illegal points in the search space, but does not exclude any legal neural network. With these goals in mind, an Abelian semi-group structure with neutral element is obtained in the set of artificial neural networks with a particular internal operation called superimposition that allows building complex neural nets from minimum useful structures. This scheme preserves the significant feature that similar neural networks only differ in one bit, which is desirable when using search algorithms. Experimental results using this codification with genetic algorithms are reported and compared to other codification methods in terms of speed of convergence and the size of the networks obtained as a solution.     

基于遗传模拟退火算法的BP算法研究

目前广泛应用于神经网络优化的方法是反向传播(Back Propagation,BP),但是BP神经网络的全局搜索能力很有限.文中探讨了两种全局优化算法:遗传算法(Genetic Algorithm,GA)和模拟退火(Simulated Annealing,SA),以及它们和BP算法结合形成的优化算法,并且比较了它们在神经网络优化中的优缺点.