Extreme Learning Machine Framework Research Articles

BC-QNet: A quantum-infused ELM model for breast cancer diagnosis

The timely and accurate diagnosis of breast cancer is pivotal for effective treatment, but current automated mammography classification methods have their constraints. In this study, we introduce an innovative hybrid model that marries the power of the Extreme Learning Machine (ELM) with FuNet transfer learning, harnessing the potential of the MIAS dataset. This novel approach leverages an Enhanced Quantum-Genetic Binary Grey Wolf Optimizer (Q-GBGWO) within the ELM framework, elevating its performance. Our contributions are twofold: firstly, we employ a feature fusion strategy to optimize feature extraction, significantly enhancing breast cancer classification accuracy. The proposed methodological motivation stems from optimizing feature extraction for improved breast cancer classification accuracy. The Q-GBGWO optimizes ELM parameters, demonstrating its efficacy within the ELM classifier. This innovation marks a considerable advancement beyond traditional methods. Through comparative evaluations against various optimization techniques, the exceptional performance of our Q-GBGWO-ELM model becomes evident. The classification accuracy of the model is exceptionally high, with rates of 96.54 % for Normal, 97.24 % for Benign, and 98.01 % for Malignant classes. Additionally, the model demonstrates a high sensitivity with rates of 96.02 % for Normal, 96.54 % for Benign, and 97.75 % for Malignant classes, and it exhibits impressive specificity with rates of 96.69 % for Normal, 97.38 % for Benign, and 98.16 % for Malignant classes. These metrics are reflected in its ability to classify three different types of breast cancer accurately. Our approach highlights the innovative integration of image data, deep feature extraction, and optimized ELM classification, marking a transformative step in advancing early breast cancer detection and enhancing patient outcomes.

Spatial-spectral graph convolutional extreme learning machine for hyperspectral image classification

ABSTRACT Hyperspectral image has excellent spectral information and abundant spatial information, and its feature quality is one of the key factors affecting the classification performance. Extreme learning machine (ELM) is widely used in hyperspectral classification problems. However, traditional ELM is usually based on regular Euclidean data, ignoring the inherent structured information between hyperspectral pixels, resulting in poor robustness. In this paper, we propose a new supervised extreme learning machine framework, termed spatial-spectral graph convolutional ELM (SSG-ELM), based on using graph convolution to extend ELM into the non-Euclidean domain. The method inherits all the advantages from ELM, and consists of a random graph convolutional layer followed by a graph convolutional regression layer, enabling it to model complex intra class variations. Otherwise, a local spectral-spatial context integration and reshaping mechanism is incorporated into the hidden layer feature representation by using a context-aware bilateral filtering procedure. Experimental results show that the proposed algorithm obtains a competitive performance and outperforms other state-of-the-art ELM-based methods.

Feature Ensemble Learning for Sensor Array Data Classification Under Low-Concentration Gas

Gas sensor array (GSA) data usually has high-dimensional features and small sample size. When a classifier is directly used for GSA data classification, it is prone to overfitting and has high time cost. The traditional solution is to perform feature dimensionality reduction before classification. However, selecting a suitable dimensionality reduction method is time-consuming and laborious, and some features useful for classification may be lost after dimensionality reduction, especially for the weak sensor response data to low concentration gas. In this paper, we proposed a feature ensemble based extreme learning machine framework (FE-ELM) for GSA data classification. In FE-ELM, downsampling is first performed on the time series of each sensor, and then the downsampled features of different sensors are combined to obtain fused feature subsets. Next, a base ELM is trained independently on each fused feature subset with all training samples by solving the least squares problem. The final FE-ELM predictions for input samples are obtained by voting the prediction results of all base ELMs. Compared with traditional methods, the proposed method solves the overfitting problem and can be directly used for GSA data classification without prior feature dimension reduction. Furthermore, the ensemble of all base classifiers with little loss of original features enables the proposed FE-ELM to have more efficient and robust classification performance. Experimental results on data from both homemade GSA under low concentration gases (ppb) and publicly available confirm that the proposed FE-ELM exceeds traditional methods and extends the detection limit of the sensor array.

Improved mayfly optimization deep stacked sparse auto encoder feature selection scorched gradient descent driven dropout XLM learning framework for software defect prediction

SummarySoftware testing is the process of improving software quality by classifying and removing defects in the software development. Previously, several methods were used for software defect prediction, but any one method did not provide sufficient accuracy. To overcome this issue, an improved may fly optimization with deep stacked sparse auto encoder feature selection scorched gradient descent driven dropout extreme learning machine framework (SDP‐IMFOFS‐GDDDXLMC) is proposed in this article for software defect prediction. Here, an IMFO method is considered for feature selection techniques. In feature selection technique, features are selected, such as PC1, PC4, and MC1 for selecting the probable minimal attribute. Then, GDDDXLMC approach is used to classify buggy and clean software detection. The proposed approach is implemented in MATLAB platform. The performance metrics, such as accuracy, precision, F‐measure, sensitivity, specificity, Mathew correlation coefficient (MCC) is examined to examine the performance of the proposed method. The simulation performance of the proposed SDP‐IMFOFS‐GDDDXLMC method attains higher accuracy 99.75%, 97.85%, 95.13%, 14.89%, 16.34%, 17.89%, and 98.79, higher sensitivity 96.34%, 91.23%, 89.12%, 12.67%, 17.56%, 18.90%, and 87.25% higher specificity 14.89%, 16.89%, 20.67%, 93.67%, 92.37%, 98.47%, and 94.78% compared with the existing methods, like SDP‐MLP‐PSO, SDP‐BPNN‐RBFNN, SDP‐CNN‐RNN‐LSTM, SDP‐KBN‐LIME, SDP‐SLDeep‐LSTM, SDP‐K‐PCA‐ELM, and SDP‐CNN‐PHI forest, respectively.

Towards extreme learning machine framework for lane detection on unmanned mobile robot

PurposeThis paper aims to focus on lane detection of unmanned mobile robots. For the mobile robot, it is undesirable to spend lots of time detecting the lane. So quickly detecting the lane in a complex environment such as poor illumination and shadows becomes a challenge.Design/methodology/approachA new learning framework based on an integration of extreme learning machine (ELM) and an inception structure named multiscale ELM is proposed, making full use of the advantages that ELM has faster convergence and convolutional neural network could extract local features in different scales. The proposed architecture is divided into two main components: self-taught feature extraction by ELM with the convolution layer and bottom-up information classification based on the feature constraint. To overcome the disadvantages of poor performance under complex conditions such as shadows and illumination, this paper mainly solves four problems: local features learning: replaced the fully connected layer, the convolutional layer is used to extract local features; feature extraction in different scales: the integration of ELM and inception structure improves the parameters learning speed, but it also achieves spatial interactivity in different scales; and the validity of the training database: a method how to find a training data set is proposed.FindingsExperimental results on various data sets reveal that the proposed algorithm effectively improves performance under complex conditions. In the actual environment, experimental results tested by the robot platform named BIT-NAZA show that the proposed algorithm achieves better performance and reliability.Originality/valueThis research can provide a theoretical and engineering basis for lane detection on unmanned robots.

Integrated framework of extreme learning machine (ELM) based on improved atom search optimization for short-term wind speed prediction

Wind energy plays an important role in terms of renewable energy. Accurate and reliable wind speed prediction is essential for effective use of wind energy. However, the uncertainty of wind speed becomes a challenging task. Aiming at these problems of wind speed prediction, this paper proposes a method based on variational mode decomposition (VMD), partial least squares (PLS), improved atom search optimization (IASO) and extreme learning machine (ELM). VMD is first employed to decompose the original wind speed data from high frequency to low frequency into multiple sub-series. Then this paper uses PLS for feature extraction and gets the best test set. And IASO is used to optimize the ELM to enhance the performance of the basic ELM model. The simulated annealing algorithm is added to the atom search optimization to enhance the local searchability. This paper employs the original wind speed data of the Sotavento Galicia wind farm in Spain as case study. Comparing results between the proposed model and the other benchmark models demonstrate the superiority of the proposed model in short-term wind speed prediction.

Aircraft Type Recognition in Remote Sensing Images: Bilinear Discriminative Extreme Learning Machine Framework

Small inter-class and massive intra-class changes are important challenges in aircraft model recognition in the field of remote sensing. Although the aircraft model recognition algorithm based on the convolutional neural network (CNN) has excellent recognition performance, it is limited by sample sets and computing resources. To solve the above problems, we propose the bilinear discriminative extreme learning machine (ELM) network (BD-ELMNet), which integrates the advantages of the CNN, autoencoder (AE), and ELM. Specifically, the BD-ELMNet first executes the convolution and pooling operations to form a convolutional ELM (ELMConvNet) to extract shallow features. Furthermore, the manifold regularized ELM-AE (MRELM-AE), which can simultaneously consider the geometrical structure and discriminative information of aircraft data, is developed to extract discriminative features. The bilinear pooling model uses the feature association information for feature fusion to enhance the substantial distinction of features. Compared with the backpropagation (BP) optimization method, BD-ELMNet adopts a layer-by-layer training method without repeated adjustments to effectively learn discriminant features. Experiments involving the application of several methods, including the proposed method, to the MTARSI benchmark demonstrate that the proposed aircraft type recognition method outperforms the state-of-the-art methods.

Robust twin extreme learning machines with correntropy-based metric

In this paper, we propose a novel distance metric based on correntropy and kernel learning. Some properties of the proposed metric are demonstrated such as nonnegativity, non-convexity, boundedness and approximation behaviors. The proposed metric includes and extends classical metrics such as L0-norm and L1-norm metrics. Moreover, we develop a fraction loss function satisfying the Bayes rule, and demonstrate its robustness from the perspective of M-estimation. With the proposed robust metric and loss function, a new robust twin extreme learning machines framework (called LCFTELM) is presented to reduce the negative effect of noises and outliers. The proposed LCFTELM retains the advantages of twin extreme machines (TELM) and promotes the robustness. However, the non-convexity of the proposed model makes it difficult to optimize. Furthermore, an effective iterative algorithm for LCFTELM is designed, we present theoretical analysis on the convergence of the proposed algorithm. Following that, we evaluate the proposed algorithm on real-world datasets and artificial dataset under different noise settings. Experimental results show that the proposed method achieves better generalization than the state-of-the-art methods in most cases, which demonstrates the feasibility and robustness of the proposed LCFTELM.

Classification of the Complex Agricultural Planting Structure with a Semi-Supervised Extreme Learning Machine Framework

Many approaches have been developed to analyze remote sensing images. However, for the classification of large-scale problems, most algorithms showed low computational efficiency and low accuracy. In this paper, the newly developed semi-supervised extreme learning machine (SS-ELM) framework with k-means clustering algorithm for image segmentation and co-training algorithm to enlarge the sample sets was used to classify the agricultural planting structure at large-scale areas. Data sets collected from a small-scale area within the Hetao Irrigation District (HID) at the upper reaches of the Yellow River basin were used to evaluate the SS-ELM framework. The results of the SS-ELM algorithm were compared with those of the random forest (RF), ELM, support vector machine (SVM) and semi-supervised support vector machine (S-SVM) algorithms. Then the SS-ELM algorithm was applied to analyze the complex planting structure of HID in 1986–2010 by comparing the remote sensing estimated results with the statistical data. In the small-scale case, the SS-ELM algorithm performed better than the RF, ELM, SVM, and S-SVM algorithms. For the SS-ELM algorithm, the average overall accuracy (OA) was in a range of 83.00–92.17%. On the contrary, for the other four algorithms, their average OA values ranged from 56.97% to 92.84%. Whereas, in the classification of planting structure in HID, the SS-ELM algorithm had an excellent performance in classification accuracy and computational efficiency for three major planting crops including maize, wheat, and sunflowers. The estimated areas by using the SS-ELM algorithm based on the remote sensing images were consistent with the statistical data, and their difference was within a range of 3–25%. This implied that the SS-ELM framework could be served as an effective method for the classification of complex planting structures with relatively fast training, good generalization, universal approximation capability, and reasonable learning accuracy.

Entropy Query by Bagging-Based Active Learning Approach in the Extreme Learning Machine Framework for Hyperspectral Image Classification

Entropy Query by Bagging-Based Active Learning Approach in the Extreme Learning Machine Framework for Hyperspectral Image Classification

Double-Level Locally Weighted Extreme Learning Machine for Soft Sensor Modeling of Complex Nonlinear Industrial Processes

In order to provide the stable and reliable prediction of key quality variables for industrial processes with complicated nonlinear characteristic, this paper proposes a Double-level Locally Weighted Extreme Learning Machine (DLWELM) based soft sensor modeling method. Firstly, a just-in-time learning based extreme learning machine framework (JITELM) is designed for adaptive nonlinear soft sensor modeling. Then, one double-level similarity measure methodology is presented with considering both the variable importance and the sample distance. At the first level, the mutual information between different input variables and output variable is computed for evaluating the importance of the input variables, which results in the variable weight coefficients. Furthermore, the variable-weighted sample distances are obtained at the second level, which are utilized to build the similarity measure for the relevant samples searching. Lastly, with the relevant samples as the modeling dataset, the locally weighted ELM (LWELM) model is developed, which assigns different weights to the training samples according to their double-level similarity values. Three cases including one numerical system, the industrial debutanizer column plant and the industrial polypropylene production process, are used to test the methods and the results demonstrate that the proposed DLWELM method has higher prediction precision compared to the basic ELM methods.

Cardiovascular Disorder Severity Detection Using Myocardial Anatomic Features Based Optimized Extreme Learning Machine Approach

ObjectivesThis study focuses on integration of anatomical left ventricle myocardium features and optimized extreme learning machine (ELM) for discrimination of subjects with normal, mild, moderate and severe abnormal ejection fraction (EF). The physiological alterations in myocardium have diagnostic relevance to the etiology of cardiovascular diseases (CVD) with reduced EF. Materials and MethodsThis assessment is carried out on cardiovascular magnetic resonance (CMR) images of 104 subjects available in Kaggle Second Annual Data Science Bowl. The Segment CMR framework is used to segment myocardium from cardiac MR images, and it is subdivided into 16 sectors. 86 clinically significant anatomical features are extracted and subjected to ELM framework. Regularization coefficient and hidden neurons influence the prediction accuracy of ELM. The optimal value for these parameters is achieved with the butterfly optimizer (BO). A comparative study of BOELM framework with different activation functions and feature set has been conducted. ResultsAmong the individual feature set, myocardial volume at ED gives a better classification accuracy of 83.3% compared to others. Further, the given BOELM framework is able to provide higher multi-class accuracy of 95.2% with the entire feature set than ELM. Better discrimination of healthy and moderate abnormal subjects is achieved than other sub groups. ConclusionThe combined anatomical sector wise myocardial features assisted BOELM is able to predict the severity levels of CVDs. Thus, this study supports the radiologists in the mass diagnosis of cardiac disorder.

ELM-MC: multi-label classification framework based on extreme learning machine

Multi-label classification methods aim to a class of application problems where each individual contains a single instance while associates with a set of labels simultaneously. In this paper, we formulate a novel multi-label classification method based on extreme learning machine framework, named ELM-MC algorithm. The essence of ELM-MC algorithm is to convert the multi-label classification problem into some single-label classifications, and fully considers the relationship among different labels. After the classification of one label, the associations with next label are applied to update the learning parameters in ELM-MC algorithm. In addition, we design a backup pool for the hidden nodes. It can help to select relatively suitable hidden nodes to the corresponding label classification case. In the simulation part, six famous databases are applied to demonstrate the satisfied classification accuracy of the proposed method.

Applying Exponential Family Distribution to Generalized Extreme Learning Machine

The learning algorithm of an extreme learning machine (ELM) has two fundamental steps: 1) random nonlinear feature transformation and 2) least squares learning. Since the probabilistic interpretation for a sample by the least squares method follows a Gaussian distribution, there are two limitations in ELM caused by the second step: 1) it may be inaccurate to handle binary classification problems, since the output of a binary dataset has a distribution far from Gaussian and 2) it may have difficulties in dealing with nontraditional data types (such as count data, ordinal data, etc.), which also do not follow Gaussian distribution. In order to solve the above-mentioned problems, this paper proposes a generalized ELM (GELM) framework by applying the exponential family distribution (EFD) to the output layer node of ELM. It simplifies the design of ELM models for task-specific output domains with different data types. We propose a unified learning paradigm for all the models under this GELM framework with different distributions in EFD, and prove that traditional ELM is a special instance of GELM by setting the output distribution as a Gaussian distribution (GELM-Gaussian). We also prove that the training of GELM-Gaussian can be finished in one iteration, in this case, GELM-Gaussian does not slow down the training speed of traditional ELM. Besides, we propose the kernel version of GELM, which can also be concretized to different models by applying different EFDs. Experimental comparisons demonstrate that GELM can give more accurate probabilistic interpretation to binary classification and GELM has a great potential in dealing with a broader range of machine learning tasks.

AUC-Based Extreme Learning Machines for Supervised and Semi-Supervised Imbalanced Classification

Extreme learning machines (ELMs) has been theoretically and experimentally proved to achieve promising performance at a fast learning speed for supervised classification tasks. However, it does not perform well on imbalanced binary classification tasks and tends to get biased toward the majority class. Besides, since a large amount of training data with labels are not always available in the real world, there is an urgent demand to develop an efficient semi-supervised version of ELM for imbalanced binary classification tasks. In this article, owing to the distinct insensitivity of area under the ROC curve (AUC) to both class skews and changes of class distributions, we focus the study on integrating AUC maximization into the ELM framework to tackle with imbalanced binary classification tasks well. By demystifying the AUC metric with the ELM framework, we develop a new AUC-based ELM called AUC-ELM for imbalanced binary classification, which essentially is revealed to be equivalent to an ELM on another transformed data space. Accordingly, its semi-supervised version called SAUC-ELM is also developed. Both AUC-ELM and SAUC-ELM have the distinctive merits: 1) they share the advantage of ELM in both generalization capability and training efficiency, and further uniquely tailored for imbalanced binary classification tasks and 2) in contrast to the existing imbalanced variants of ELM, such as class-specific cost regulation ELM and semi-supervised ELM, they have fewer parameters to tune, thereby reducing the computational cost for model selection. Experiments on a heap of datasets show that both AUC-ELM and SAUC-ELM outperform the other comparative methods in terms of both classification performance and training speed.

Negative correlation learning in the extreme learning machine framework

Extreme learning machine (ELM) has shown to be a suitable algorithm for classification problems. Several ensemble meta-algorithms have been developed in order to generalize the results of ELM models. Ensemble approaches introduced in the ELM literature mainly come from boosting and bagging frameworks. The generalization of these methods relies on data sampling procedures, under the assumption that training data are heterogeneously enough to set up diverse base learners. The proposed ELM ensemble model overcomes this strong assumption by using the negative correlation learning (NCL) framework. An alternative diversity metric based on the orthogonality of the outputs is proposed. The error function formulation allows us to develop an analytical solution to the parameters of the ELM base learners, which significantly reduce the computational burden of the standard NCL ensemble method. The proposed ensemble method has been validated by an experimental study with a variety of benchmark datasets, comparing it with the existing ensemble methods in ELM. Finally, the proposed method statistically outperforms the comparison ensemble methods in accuracy, also reporting a competitive computational burden (specially if compared to the baseline NCL-inspired method).

A New Probabilistic Output Constrained Optimization Extreme Learning Machine

In near decades machine learning approaches have received overwhelming attention from many researchers for solving problems that cannot be ironed out by traditional approaches. However, most of these approaches produces output that is not equivalent to the probability estimates of how credible and reliable the output can be for each prediction. One widely utilized, highly accorded for generalized performance but non-probabilistic machine learning algorithm is the Extreme Learning Machine (ELM). As with other classification systems, ELM generates outputs that cannot be treated as probabilities. Current literature shows approaches attempt to assimilate probabilistic concept in ELM however their outputs are not equivalent to probabilities. Furthermore, these methods invoke two-stage post processing procedures with iterative learning procedures which are against the salient features of ELM that highlight no iterative operations involved in learning. Hence, we want to probe in this paper the ability of ELM to produce probabilistic output from the original architecture of ELM itself while preserving the merits of ELM without the need for a post processing two-stage procedures to convert the output to probability and eliminates iterative learning to compute output weights. Two methodologies of unified probabilistic ELM framework are presented, i.e., Probabilistic Output Extreme Learning Machine (PO-ELM) and Constrained Optimization Posterior Probabilistic Outputs based Extreme Learning Machine (CPP-POELM). The proposed models are evaluated empirically on several benchmark datasets as well as real world power system applications to demonstrate its validity and efficacy in handling pattern classification problems as well as decision making process.

Extreme semi-supervised learning for multiclass classification

Semi-Supervised Support Vector Machines (S3VMs) provide a powerful framework for Semi-Supervised Learning (SSL) tasks which leverage widely available unlabeled data to improve performance. However, there exist three issues in S3VMs: (i) S3VMs require concurrently training c one-against-all (OAA) classifiers (c is the number of classes) for multiclass classification, which is prohibitive for large c; (ii) S3VMs require huge computational time and large storage (because of the large kernel matrix) in large-scale training and testing; (iii) S3VMs require the balance constraint in the unlabeled data, which not only needs prior knowledge from the unlabeled data (the prior knowledge is unavailable in some applications), but also makes their nonconvex optimization problem more intractable. To address these issues, a novel method called Extreme Semi-Supervised Learning (ESSL) is proposed in this paper. First, the framework of Extreme Learning Machine (ELM) is adopted to handle both binary and multiclass classification problems in a unified model. Second, the hidden layer is encoded by an extremely small approximate empirical kernel map (AEKM) to greatly reduce the computational cost and the memory usage for training and testing. Third, the balance constraint (prior knowledge) in the unlabeled data is removed through the elaborative design of weighting function (which emphasizes the importance of labeled data and the minority pattern in the labeled data).By these three ways, ESSL can be solved effectively and efficiently based on alternating optimization (AO). More specifically, ESSL can be analytically and simply solved by generalized pseudoinverse and oneHotMap function (without any optimization solver and the OAA strategy) in the AO procedure, and consequently, better performance and much faster training speed are always achieved in ESSL. Our empirical study shows that ESSL significantly outperforms existing efficient SSL methods (e.g., meanS3VM and SS-ELM) in terms of accuracy, efficiency and memory, especially for large-scale multiclass problems. As an example, on the 20Newsgroups dataset, ESSL respectively runs 45 and 120 times faster than meanS3VM for training and testing with the improvement in accuracy of 3%, while the memory usage is reduced to 1/14. It is noteworthy that even though all the model parameters are with default values, ESSL already produces very excellent performance without fine-tuning parameters.

Regularized ensemble neural networks models in the Extreme Learning Machine framework

Extreme Learning Machine (ELM) has proven to be an efficient and speedy algorithm for classification. In order to generalize the results of standard ELM, several ensemble meta-algorithms have been implemented. On this manuscript, we propose a hierarchical ensemble methodology that promotes diversity among the elements of an ensemble, explicitly through the loss function in the single-hidden-layer feedforward network version of ELM. The diversity term in the loss function is justified using the concept of regularization from the Negative Correlation Learning framework. Statistical tests show that our proposal is competitive in both performance and diversity measures against bagging and boosting ensemble methodologies.

Cross-Domain Extreme Learning Machines for Domain Adaptation

Extreme learning machines (ELMs), as “generalized” single hidden layer feedforward networks, have been proved to be effective and efficient for classification and regression problems. Traditional ELMs assume that the training and testing data are drawn from the same distribution, which however is often violated in real-world applications. In this paper, we propose a unified cross-domain ELM (CDELM) framework to address domain adaptation problems, in which the distributions of training data ( source domain ) and testing data ( target domain ) are different but related. CDELM not only fully leverages labeled source data and unlabeled target data simultaneously to construct an adaptive target classifier but also maintains the computational efficiency of ELMs. Specifically, CDELM adapts the source classifier to target domain by matching the projected means of both domains, and explores the structure property of target domain by using manifold regularization to make the final classifier more adaptable to target data. Based on the framework, two algorithms CDELM-M and CDELM-C are proposed, which aim at minimizing the marginal and conditional distribution distance between source and target domains, respectively. Moreover, CDELM-C can further enhance the classification accuracy by multiple iterations. Comprehensive experimental studies on artificial datasets and public text and image datasets demonstrate that both CDELM-M and CDELM-C are competitive with several state-of-the-art domain adaptation learning methods in terms of the classification accuracy and efficiency.