81 research outputs found

    Learning enhancement of radial basis function network with particle swarm optimization

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    Back propagation (BP) algorithm is the most common technique in Artificial Neural Network (ANN) learning, and this includes Radial Basis Function Network. However, major disadvantages of BP are its convergence rate is relatively slow and always being trapped at the local minima. To overcome this problem, Particle Swarm Optimization (PSO) has been implemented to enhance ANN learning to increase the performance of network in terms of convergence rate and accuracy. In Back Propagation Radial Basis Function Network (BP-RBFN), there are many elements to be considered. These include the number of input nodes, hidden nodes, output nodes, learning rate, bias, minimum error and activation/transfer functions. These elements will affect the speed of RBF Network learning. In this study, Particle Swarm Optimization (PSO) is incorporated into RBF Network to enhance the learning performance of the network. Two algorithms have been developed on error optimization for Back Propagation of Radial Basis Function Network (BP-RBFN) and Particle Swarm Optimization of Radial Basis Function Network (PSO-RBFN) to seek and generate better network performance. The results show that PSO-RBFN give promising outputs with faster convergence rate and better classifications compared to BP-RBFN

    Improved RBF Network Intrusion Detection Model Based on Edge Computing with Multi-algorithm Fusion

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    Edge computing is difficult to deploy a complete and reliable security strategy due to its distributed computing architecture and inherent heterogeneity of equipment and limited resources. When malicious attacks occur, the loss will be immeasurable. RBF neural network has strong nonlinear representation ability and fast learning convergence speed, which is suitable for intrusion detection of edge detection industrial control network. In this paper, an improved RBF network intrusion detection model based on multi-algorithm fusion is proposed. kernel principal component analysis (KPCA) is used to extract data dimension and simplify data representation. Then subtractive clustering algorithm(SCM) and grey wolf algorithm(GWO) are used to jointly optimize RBF neural network parameters to avoid falling into local optimum, reduce the calculation of model training and improve the detection accuracy. The algorithm can better adapt to the edge computing platform with weak computing ability and bearing capacity, and realize real-time data analysis.The experimental results of BATADAL data set and Gas data set show that the accuracy of the algorithm is over 99% and the training time of larger samples is shortened by 50 times for BATADAL data set. The results show that the improved RBF network is effective in improving the convergence speed and accuracy in intrusion detection

    A Novel Fuzzy Clustering Algorithm for Radial Basis Function Neural Network

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    A Fuzzy Radial basis function neural network (FRBFNN) classifier is proposed in the framework of Radial basis function neural network (RBFNN). This classifier is constructed using class-specific fuzzy clustering to form the clusters which represent the neurons i.e. fuzzy set hyperspheres (FSHs) in the hidden layer of FRBFNN. The creation of these FSHs is based on the maximum spread from inter-class information and intra-class fuzzy membership mechanism. The proposed approach is fast, independent of parameters, and shows good data visualization. The Least mean square training between the hidden layer to output layer in RBFNN is avoided, thus reduces the time complexity. The FRBFNN is trained quickly due to the fast converge of input data to form the FHSs in the hidden layer. The output is determined by the union operation of the FHSs outputs which are connected to the class nodes in the output layer. The performance of the proposed FRBFNN is compared with the other RBFNNs using ten benchmark datasets. The empirical findings demonstrate that the proposed FRBFNN is highly efficient classifier for pattern recognition

    Radial Basis Function Neural Networks : A Review

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    Radial Basis Function neural networks (RBFNNs) represent an attractive alternative to other neural network models. One reason is that they form a unifying link between function approximation, regularization, noisy interpolation, classification and density estimation. It is also the case that training RBF neural networks is faster than training multi-layer perceptron networks. RBFNN learning is usually split into an unsupervised part, where center and widths of the Gaussian basis functions are set, and a linear supervised part for weight computation. This paper reviews various learning methods for determining centers, widths, and synaptic weights of RBFNN. In addition, we will point to some applications of RBFNN in various fields. In the end, we name software that can be used for implementing RBFNNs

    Effort estimation for object-oriented system using artificial intelligence techniques

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    Software effort estimation is a vital task in software engineering. The importance of effort estimation becomes critical during early stage of the software life cycle when the details of the software have not been revealed yet. The effort involved in developing a software product plays an important role in determining the success or failure. With the proliferation of software projects and the heterogeneity in their genre, there is a need for efficient effort estimation techniques to enable the project managers to perform proper planning of the Software Life Cycle activates. In the context of developing software using object-oriented methodologies, traditional methods and metrics were extended to help managers in effort estimation activity. There are basically some points approach, which are available for software effort estimation such as Function Point, Use Case Point, Class Point, Object Point, etc. In this thesis, the main goal is to estimate the effort of various software projects using Class Point Approach. The parameters are optimized using various artificial intelligence (AI) techniques such as Multi-Layer Perceptron (MLP), K-Nearest Neighbor Regression (KNN) and Radial Basis Function Network(RBFN), fuzzy logic with various clustering algorithms such as the Fuzzy C-means (FCM) algorithm, K-means clustering algorithm and Subtractive Clustering (SC) algorithm, such as to achieve better accuracy. Furthermore, a comparative analysis of software effort estimation using these various AI techniques has been provided. By estimating the software projects accurately, we can have software with acceptable quality within budget and on planned schedules

    Soft Computing Techniques for Stock Market Prediction: A Literature Survey

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    Stock market trading is an unending investment exercise globally. It has potentials to generate high returns on investors’ investment. However, it is characterized by high risk of investment hence, having knowledge and ability to predict stock price or market movement is invaluable to investors in the stock market. Over the years, several soft computing techniques have been used to analyze various stock markets to retrieve knowledge to guide investors on when to buy or sell. This paper surveys over 100 published articles that focus on the application of soft computing techniques to forecast stock markets. The aim of this paper is to present a coherent of information on various soft computing techniques employed for stock market prediction. This research work will enable researchers in this field to know the current trend as well as help to inform their future research efforts. From the surveyed articles, it is evident that researchers have firmly focused on the development of hybrid prediction models and substantial work has also been done on the use of social media data for stock market prediction. It is also revealing that most studies have focused on the prediction of stock prices in emerging market

    Modelagem de Sistemas Dinâmicos Não Lineares via RBF-GOBF.

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    Trata-se neste trabalho trata da modelagem e identificação de sistemas dinâmicos não lineares estáveis representáveis por modelos de Wiener por um estrutura formada por bases de funções ortonormais generalizadas (Generalized Orthonormal Basis Functions - GOBF) com funções internas e redes neurais com funções de base radial (Radial Basis Functions - RBF). Os modelos GOBF com funções internas são capazes de representar dinâmicas lineares intrincadas com uma parametrização que se vale apenas de valores reais, sejam os polos do sistema a ser representado complexos e/ou reais. Com informações de entrada e saída do sistema a ser identificado é possível obter um modelo GOBF-RBF inicial. Os clusters que determinam os parâmetros inciais das RBFs (centros das funções gaussianas e larguras ou spreads) são obtidos pelo método fuzzy C-means, o qual é inicializado com um número de centros pré-determinado, obtido pela técnica subtractive clustering, garantindo clusters com volume e densidade apropriados. São propostas duas técnicas para o ajuste dos parâmetros da estrutura. A primeira delas se baseia em um método de otimização não linear e os gradientes exatos da estrutura. Apresenta-se um procedimento para a obtenção dos cálculos analíticos dos gradientes de saída do modelo GOBF-RBF em relação a seus parâmetros (polos da base ortonormal, centros, larguras e pesos de saída da rede RBF). A segunda proposta se vale de um método metaheurístico chamado otimização por enxame de partículas com comportamento quântico. As metodologias são validadas com suas aplicações em três diferentes sistemas não lineares associados a modelos de processos práticos

    Cuckoo search based adaptive neuro-fuzzy inference system for short-term load forecasting

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    Short-Term Load Forecasting (STLF) is an essential input for power system operation computations to achieve proper system balancing. General economy and security of power system depend on accurate STLF. The accuracy of forecasting model depends on the number and types of the forecasting variables. Furthermore, a day-ahead hourly-load forecast has to reach the decision makers before the elapse of a pre-set time. Conventional methods used in determining future load demand were not able to explore all the available variables in a particular forecasting region. Moreover, artificial intelligence methods like Adaptive Neuro-Fuzzy Inference System (ANFIS), are associated with computational difficulties, thus influence the speed and accuracy of the model. Therefore, these variables need to be investigated so as to make the forecasting model simple and easy to use. Similarly, the forecasting speed needs to be improved. This thesis presents the development of short-term electric load demand forecasting algorithm, with the aim to improve the forecasting accuracy and speed. It starts with the development of data selection and data processing framework, through the use of correlation analysis, hypothesis test and wavelet transform. Variables of the four seasons in one year were investigated and were classified based on the available weather and historical load data in each season. To reduce the variability in the forecasting data, wavelet transform is used. The whole forecasting algorithm has been developed by integrating Cuckoo Search (CS) algorithm with ANFIS to produce CS-ANFIS model. CS was used to improve the forecasting capability and speed of the traditional ANFIS, by replacing the derivative-based gradient descent optimization algorithm with CS in backward pass. Its purpose is to update the antecedent parameters of the traditional ANFIS, through the determination of an optimal value of the error merging between the ANFIS output and targeted output. The whole system is validated by the comparison with an existing ANFIS model, and two other ANFIS models optimized with Particle Swarm Optimization (PSO-ANFIS) and Genetic Algorithm (GA-ANFIS). The developed CS-ANFIS model proved to be superior to these models in terms of accuracy and forecasting time. A reduction in average mean absolute percentage error of 84.48% for one year forecast is recorded using the developed CS-ANFIS, and 77.32% with the proposed data selection approach. The model was found to forecast the future load demand within an average period of 37 seconds, as compared to the traditional ANFIS which recorded an average forecasting time of 219 seconds. It can therefore, be accepted as a tool for forecasting future energy demand at utility level to improve the reliability and economic operation of the utility
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