Basis Function Extreme Learning Machine Research Articles

A method for mixed data classification base on RBF-ELM network

The classification tasks for numerical or categorical data have been well developed. However, the data collected in the real world are frequently the mixed type containing numerical and categorical values, and how to classify the mixed data quickly and efficiently is a critical yet challenging task. Existing classification models for mixed data usually treat the mixed data processing and subsequent classification as two independent phases, without considering their compatibility. By fusing the mixed data processing into a classification algorithm, this paper proposes an extended version of RBF-ELM (Radial Basis Function-Extreme Learning Machine), a Mixed Data RBF-ELM method (MD-RBF-ELM for short), which can achieve direct, fast, and efficient classification for mixed data. Specifically, a distance metric method for mixed data is firstly designed to calculate the distances between the input data and the RBF centers, and then these distances are used to train the network structure and weights of MD-RBF-ELM, thereby realizing the fusion of data processing with model learning. In addition, to alleviate the problem of MD-RBF-ELM’s unstable performance caused by randomly selecting the RBF centers, we propose an improved density peak clustering algorithm and use it to select the optimal RBF centers automatically and adaptively. Extensive experimental results on 34 data sets demonstrate that MD-RBF-ELM significantly enhances the classification performance (increasing 2.37% for F1-score, up to 14/34 for the number of best results, and reaching 2.4/8 for the averaged ranks), compared with seven state-of-the-art competitors.

A novel maximum and minimum response-based Gabor (MMRG) feature extraction method for facial expression recognition

In facial expression recognition applications, the images are corrupted with random noise, and this affects the classification accuracy. This article proposes a maximum and Minimum Response-based Gabor (MMRG) that can encode the facial texture more discriminatively and eliminate random noise. Two code images are produced from the available Gabor images. Then, after dividing the code images into grids, feature vectors are formed using histograms. A technique based on the bat algorithm is proposed for the optimization of the Gabor filter banks as Bat Algorithm-based Gabor Optimization (BAGO). The MMRG increases the efficiency of Gabor filter-based features by precisely distinguishing the texture frequencies. It also helps in reducing the dimensions of feature vector which is a major problem in Gabor filter-based feature extraction. Radial Basis Function-Extreme Learning Machine (RBF-ELM) classifier is used for a faster and accurate multi-classification. The proposed approach has been evaluated with six datasets namely, Japanese Female Facial Expression (JAFFE), Cohn Kanade (CK+), Multi-media Understanding Group (MUG), Static Facial Expressions in the Wild (SFEW), Oulu-Chinese Academy of Science, Institute of Automation (Oulu-CASIA) and Man–Machine Interaction (MMI) datasets to meet a classification accuracy of 97.2, 97.4, 95.4, 35.4, 87.4 and 82.3% for seven class emotion detection, which is high when compared to other state-of –the-art methods.

Evaluation of feature extraction techniques and classifiers for finger movement recognition using surface electromyography signal.

Electromyography (EMG) in a bio-driven system is used as a control signal, for driving a hand prosthesis or other wearable assistive devices. Processing to get informative drive signals involves three main modules: preprocessing, dimensionality reduction, and classification. This paper proposes a system for classifying a six-channel EMG signal from 14 finger movements. A feature vector of 66 elements was determined from the six-channel EMG signal for each finger movement. Subsequently, various feature extraction techniques and classifiers were tested and evaluated. We compared the performance of six feature extraction techniques, namely principal component analysis (PCA), linear discriminant analysis (LDA), uncorrelated linear discriminant analysis (ULDA), orthogonal fuzzy neighborhood discriminant analysis (OFNDA), spectral regression linear discriminant analysis (SRLDA), and spectral regression extreme learning machine (SRELM). In addition, we also evaluated the performance of seven classifiers consisting of support vector machine (SVM), linear classifier (LC), naive Bayes (NB), k-nearest neighbors (KNN), radial basis function extreme learning machine (RBF-ELM), adaptive wavelet extreme learning machine (AW-ELM), and neural network (NN). The results showed that the combination of SRELM as the feature extraction technique and NN as the classifier yielded the best classification accuracy of 99%, which was significantly higher than those from the other combinations tested. Graphical abstract Mean of classification accuracies for 14 finger movements obtained with various pairs of SRELM and classifier.

Comparison Of Modeling Techniques To Be Used As An Objective Function In Optimization Techniques

In recent years, the stringent environmental regulations from the government have made the automotive industry to find alternative ways to decrease the emission level in the internal combustion engines. Compressed natural gas (CNG) is a promising alternative fuel, which decreases emissions, in dual fuel mode; the thermal efficiency is slightly less than that of a diesel engine. Optimizing the input parameters like load, CNG flow rate, and compression ratio, such that the output parameters like efficiency are high and emissions are lower, is very important.Optimization techniques are being widely used in this efforts. In this paper, an attempt has been made to compare different modeling techniques like Adaptive neuro fuzzy inference system (ANFIS), radial basis function extreme learning machine (RBF-ELM), and response surface methodology (RSM), to evaluate them and to identify the best possible alternative as an objective function for use in optimization techniques.

Hybrid Structure-Adaptive RBF-ELM Network Classifier

In this paper, a hybrid structure-adaptive radial basis function-extreme learning machine (HSARBF-ELM) network classifier is presented. HSARBF-ELM consists of a structure-adaptive radial basis function (SARBF) network and an extreme learning machine (ELM) network of cascade, where the output of the SARBF network hidden layer is used as the input layer of the ELM network. In the HSARBF-ELM network classifier, the SARBF network is utilized to achieve adaptively localizing kernel mapping of input vectors, after that step, the ELM network is utilized to implement global classification of mapping samples in the kernel space. HSARBF-ELM indicates the combination of localized kernel mapping learning and the global nonlinear classification, which combines the advantages of the SARBF network and the ELM network. The quantitative conditions for the separability enhancement and the corresponding theoretical explanation for the HSARBF-ELM network are given, which demonstrate that when input vectors go through the SARBF network, adaptively adjusting the RBF kernel parameters can boost the separability of the original sample space. Thus, the classification performance of the HSARBF-ELM network can be guaranteed theoretically. An appropriate learning algorithm for the HSARBF-ELM network is subsequently presented, which effectively combines the methods of density clustering with a potential function, center-oriented unidirectional repulsive force and the existing ELM algorithm, and the optimized complementary HSARBF-ELM network can be constructed. The experimental results show that the classification performance of the HSARBF-ELM network clearly outperforms the ELM network, and outperforms other classifiers on most classification problems.

Unsupervised Feature Learning Classification With Radial Basis Function Extreme Learning Machine Using Graphic Processors.

Ever-increasing size and complexity of data sets create challenges and potential tradeoffs of accuracy and speed in learning algorithms. This paper offers progress on both fronts. It presents a mechanism to train the unsupervised learning features learned from only one layer to improve performance in both speed and accuracy. The features are learned by an unsupervised feature learning (UFL) algorithm. Then, those features are trained by a fast radial basis function (RBF) extreme learning machine (ELM). By exploiting the massive parallel computing attribute of modern graphics processing unit, a customized compute unified device architecture (CUDA) kernel is developed to further speed up the computing of the RBF kernel in the ELM. Results tested on Canadian Institute for Advanced Research and Mixed National Institute of Standards and Technology data sets confirm the UFL RBF ELM achieves high accuracy, and the CUDA implementation is up to 20 times faster than CPU and the naive parallel approach.