58,318 research outputs found
A Comparative Performance Analysis of Hybrid and Classical Machine Learning Method in Predicting Diabetes
Diabetes mellitus is one of medical science’s most important research topics because of the disease’s severe consequences. High blood glucose levels characterize it. Early detection of diabetes is made possible by machine learning techniques with their intelligent capabilities to accurately predict diabetes and prevent its complications. Therefore, this study aims to find a machine learning approach that can more accurately predict diabetes. This study compares the performance of various classical machine learning models with the hybrid machine learning approach. The hybrid model includes the homogenous model, which comprises Random Forest, AdaBoost, XGBoost, Extra Trees, Gradient Booster, and the heterogeneous model that uses stacking ensemble methods. The stacking ensemble or stacked generalization approach is a meta-classifier in which multiple learners collaborate for prediction. The performance of the homogeneous hybrid models, Stacked Generalization and the classic machine learning methods such as Naive Bayes and Multilayer Perceptron, k-Nearest Neighbour, and support vector machine are compared. The experimental analysis using Pima Indians and the early-stage diabetes dataset demonstrates that the hybrid models achieve higher accuracy in diagnosing diabetes than the classical models. In the comparison of all the hybrid models, the heterogeneous model using the Stacked Generalization approach outperformed other models by achieving 83.9% and 98.5%. Doi: 10.28991/ESJ-2023-07-01-08 Full Text: PD
A Review of Feature Selection and Classification Approaches for Heart Disease Prediction
Cardiovascular disease has been the number one illness to cause death in the world for years. As information technology develops, many researchers have conducted studies on a computer-assisted diagnosis for heart disease. Predicting heart disease using a computer-assisted system can reduce time and costs. Feature selection can be used to choose the most relevant variables for heart disease. It includes filter, wrapper, embedded, and hybrid. The filter method excels in computation speed. The wrapper and embedded methods consider feature dependencies and interact with classifiers. The hybrid method takes advantage of several methods. Classification is a data mining technique to predict heart disease. It includes traditional machine learning, ensemble learning, hybrid, and deep learning. Traditional machine learning uses a specific algorithm. The ensemble learning combines the predictions of multiple classifiers to improve the performance of a single classifier. The hybrid approach combines some techniques and takes advantage of each method. Deep learning does not require a predetermined feature engineering. This research provides an overview of feature selection and classification methods for the prediction of heart disease in the last ten years. Thus, it can be used as a reference in choosing a method for heart disease prediction for future research
Combining Stochastic Parameterized Reduced-Order Models with Machine Learning for Data Assimilation and Uncertainty Quantification with Partial Observations
A hybrid data assimilation algorithm is developed for complex dynamical
systems with partial observations. The method starts with applying a spectral
decomposition to the entire spatiotemporal fields, followed by creating a
machine learning model that builds a nonlinear map between the coefficients of
observed and unobserved state variables for each spectral mode. A cheap
low-order nonlinear stochastic parameterized extended Kalman filter (SPEKF)
model is employed as the forecast model in the ensemble Kalman filter to deal
with each mode associated with the observed variables. The resulting ensemble
members are then fed into the machine learning model to create an ensemble of
the corresponding unobserved variables. In addition to the ensemble spread, the
training residual in the machine learning-induced nonlinear map is further
incorporated into the state estimation that advances the quantification of the
posterior uncertainty. The hybrid data assimilation algorithm is applied to a
precipitating quasi-geostrophic (PQG) model, which includes the effects of
water vapor, clouds, and rainfall beyond the classical two-level QG model. The
complicated nonlinearities in the PQG equations prevent traditional methods
from building simple and accurate reduced-order forecast models. In contrast,
the SPEKF model is skillful in recovering the intermittent observed states, and
the machine learning model effectively estimates the chaotic unobserved
signals. Utilizing the calibrated SPEKF and machine learning models under a
moderate cloud fraction, the resulting hybrid data assimilation remains
reasonably accurate when applied to other geophysical scenarios with nearly
clear skies or relatively heavy rainfall, implying the robustness of the
algorithm for extrapolation
Evaluating raw waveforms with deep learning frameworks for speech emotion recognition
Speech emotion recognition is a challenging task in speech processing field.
For this reason, feature extraction process has a crucial importance to
demonstrate and process the speech signals. In this work, we represent a model,
which feeds raw audio files directly into the deep neural networks without any
feature extraction stage for the recognition of emotions utilizing six
different data sets, EMO-DB, RAVDESS, TESS, CREMA, SAVEE, and TESS+RAVDESS. To
demonstrate the contribution of proposed model, the performance of traditional
feature extraction techniques namely, mel-scale spectogram, mel-frequency
cepstral coefficients, are blended with machine learning algorithms, ensemble
learning methods, deep and hybrid deep learning techniques. Support vector
machine, decision tree, naive Bayes, random forests models are evaluated as
machine learning algorithms while majority voting and stacking methods are
assessed as ensemble learning techniques. Moreover, convolutional neural
networks, long short-term memory networks, and hybrid CNN- LSTM model are
evaluated as deep learning techniques and compared with machine learning and
ensemble learning methods. To demonstrate the effectiveness of proposed model,
the comparison with state-of-the-art studies are carried out. Based on the
experiment results, CNN model excels existent approaches with 95.86% of
accuracy for TESS+RAVDESS data set using raw audio files, thence determining
the new state-of-the-art. The proposed model performs 90.34% of accuracy for
EMO-DB with CNN model, 90.42% of accuracy for RAVDESS with CNN model, 99.48% of
accuracy for TESS with LSTM model, 69.72% of accuracy for CREMA with CNN model,
85.76% of accuracy for SAVEE with CNN model in speaker-independent audio
categorization problems.Comment: 14 pages, 6 Figures, 8 Table
Hybrid Neuro-Fuzzy Classifier Based On Nefclass Model
The paper presents hybrid neuro-fuzzy classifier, based on NEFCLASS model, which wasmodified. The presented classifier was compared to popular classifiers – neural networks andk-nearest neighbours. Efficiency of modifications in classifier was compared with methodsused in original model NEFCLASS (learning methods). Accuracy of classifier was testedusing 3 datasets from UCI Machine Learning Repository: iris, wine and breast cancer wisconsin.Moreover, influence of ensemble classification methods on classification accuracy waspresented
A Hybrid Machine Learning Framework for Predicting Students’ Performance in Virtual Learning Environment
Virtual Learning Environments (VLE), such as Moodle and Blackboard, store vast data to help identify students\u27 performance and engagement. As a result, researchers have been focusing their efforts on assisting educational institutions in providing machine learning models to predict at-risk students and improve their performance. However, it requires an efficient approach to construct a model that can ultimately provide accurate predictions. Consequently, this study proposes a hybrid machine learning framework to predict students\u27 performance using eight classification algorithms and three ensemble methods (Bagging, Boosting, Voting) to determine the best-performing predictive model. In addition, this study used filter-based and wrapper-based feature selection techniques to select the best features of the dataset related to students\u27 performance. The obtained results reveal that the ensemble methods recorded higher predictive accuracy when compared to single classifiers. Furthermore, the accuracy of the models improved due to the feature selection techniques utilized in this study
Modelling and Forecasting Temporal PM<sub>2.5</sub> Concentration Using Ensemble Machine Learning Methods
Exposure of humans to high concentrations of PM2.5 has adverse effects on their health. Researchers estimate that exposure to particulate matter from fossil fuel emissions accounted for 18% of deaths in 2018—a challenge policymakers argue is being exacerbated by the increase in the number of extreme weather events and rapid urbanization as they tinker with strategies for reducing air pollutants. Drawing on a number of ensemble machine learning methods that have emerged as a result of advancements in data science, this study examines the effectiveness of using ensemble models for forecasting the concentrations of air pollutants, using PM2.5 as a representative case. A comprehensive evaluation of the ensemble methods was carried out by comparing their predictive performance with that of other standalone algorithms. The findings suggest that hybrid models provide useful tools for PM2.5 concentration forecasting. The developed models show that machine learning models are efficient in predicting air particulate concentrations, and can be used for air pollution forecasting. This study also provides insights into how climatic factors influence the concentrations of pollutants found in the air
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Building more accurate decision trees with the additive tree.
The expansion of machine learning to high-stakes application domains such as medicine, finance, and criminal justice, where making informed decisions requires clear understanding of the model, has increased the interest in interpretable machine learning. The widely used Classification and Regression Trees (CART) have played a major role in health sciences, due to their simple and intuitive explanation of predictions. Ensemble methods like gradient boosting can improve the accuracy of decision trees, but at the expense of the interpretability of the generated model. Additive models, such as those produced by gradient boosting, and full interaction models, such as CART, have been investigated largely in isolation. We show that these models exist along a spectrum, revealing previously unseen connections between these approaches. This paper introduces a rigorous formalization for the additive tree, an empirically validated learning technique for creating a single decision tree, and shows that this method can produce models equivalent to CART or gradient boosted stumps at the extremes by varying a single parameter. Although the additive tree is designed primarily to provide both the model interpretability and predictive performance needed for high-stakes applications like medicine, it also can produce decision trees represented by hybrid models between CART and boosted stumps that can outperform either of these approaches
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