Gaussian Naive Bayes Classifier Research Articles

A Feature-Driven Decision Support System for Heart Failure Prediction Based on χ 2 Statistical Model and Gaussian Naive Bayes.

Heart failure (HF) is considered a deadliest disease worldwide. Therefore, different intelligent medical decision support systems have been widely proposed for detection of HF in literature. However, low rate of accuracies achieved on the HF data is a major problem in these decision support systems. To improve the prediction accuracy, we have developed a feature-driven decision support system consisting of two main stages. In the first stage, χ2 statistical model is used to rank the commonly used 13 HF features. Based on the χ2 test score, an optimal subset of features is searched using forward best-first search strategy. In the second stage, Gaussian Naive Bayes (GNB) classifier is used as a predictive model. The performance of the newly proposed method (χ2-GNB) is evaluated by using an online heart disease database of 297 subjects. Experimental results show that our proposed method could achieve a prediction accuracy of 93.33%. The developed method (i.e., χ2-GNB) improves the HF prediction performance of GNB model by 3.33%. Moreover, the newly proposed method also shows better performance than the available methods in literature that achieved accuracies in the range of 57.85–92.22%.

Classification of Benign and Malignant Breast Cancer using Supervised Machine Learning Algorithms Based on Image and Numeric Datasets

Breast cancer has been identified as the second leading cause of death among women worldwide after lung cancer and hence, it becomes extremely crucial to identify it at an early stage, which can considerably increase the chances of survival. The most important part in cancer detection is to be able to differentiate between benign and malignant tumors and this is where the work of Machine Learning comes in. Taking all the dependent features upon consideration, Supervised Machine Learning methods allow for classification with higher degree of accuracy and improve upon the misdiagnosis of the physicians, which might occur almost 20% of the time. In our paper, we are focusing towards understanding the shortcomings of digital mammograms in detection of breast cancer and utilize Machine Learning classifiers for the classification of benign and malignant tumors using image analysis. Apart from this, we are also looking into implementing Supervised Machine Learning classifiers such as Decision Tree, K Nearest Neighbour (KNN), Random Forest and Gaussian Naive Bayes classifiers for assessing the risks involved with breast cancer by analyzing the biomarkers that are involved with it. Our aim is to provide a comprehensive view on prediction of breast cancer through Machine Learning through both image and data analyses, which can play a pivotal role in prevention of misdiagnosis in future. Fig. 1. gives a layout for the breast cancer prediction using Supervised Machine learning classifiers.

Building Risk Prediction Models for Type 2 Diabetes Using Machine Learning Techniques.

IntroductionAs one of the most prevalent chronic diseases in the United States, diabetes, especially type 2 diabetes, affects the health of millions of people and puts an enormous financial burden on the US economy. We aimed to develop predictive models to identify risk factors for type 2 diabetes, which could help facilitate early diagnosis and intervention and also reduce medical costs.MethodsWe analyzed cross-sectional data on 138,146 participants, including 20,467 with type 2 diabetes, from the 2014 Behavioral Risk Factor Surveillance System. We built several machine learning models for predicting type 2 diabetes, including support vector machine, decision tree, logistic regression, random forest, neural network, and Gaussian Naive Bayes classifiers. We used univariable and multivariable weighted logistic regression models to investigate the associations of potential risk factors with type 2 diabetes.ResultsAll predictive models for type 2 diabetes achieved a high area under the curve (AUC), ranging from 0.7182 to 0.7949. Although the neural network model had the highest accuracy (82.4%), specificity (90.2%), and AUC (0.7949), the decision tree model had the highest sensitivity (51.6%) for type 2 diabetes. We found that people who slept 9 or more hours per day (adjusted odds ratio [aOR] = 1.13, 95% confidence interval [CI], 1.03–1.25) or had checkup frequency of less than 1 year (aOR = 2.31, 95% CI, 1.86–2.85) had higher risk for type 2 diabetes.ConclusionOf the 8 predictive models, the neural network model gave the best model performance with the highest AUC value; however, the decision tree model is preferred for initial screening for type 2 diabetes because it had the highest sensitivity and, therefore, detection rate. We confirmed previously reported risk factors and also identified sleeping time and frequency of checkup as 2 new potential risk factors related to type 2 diabetes.

True-Color Three-Dimensional Imaging and Target Classification BASED on Hyperspectral LiDAR

True-color three-dimensional (3D) imaging exploits spatial and spectral information and can enable accurate feature extraction and object classification. The existing methods, however, are limited by data collection mechanisms when realizing true-color 3D imaging. We overcome this problem and present a novel true-color 3D imaging method based on a 32-channel hyperspectral LiDAR (HSL) covering a 431–751 nm spectral range. We conducted two experiments, one with nine-color card papers and the other with seven different colored objects. We used the former to investigate the effect of true-color 3D imaging and determine the optimal spectral bands for compositing true-color, and the latter to explore the classification potential based on the true-color feature using polynomial support vector machine (SVM) and Gaussian naive Bayes (NB) classifiers. Since using all bands of HSL will cause color distortions, the optimal spectral band combination for better compositing the true-color were selected by principal component analysis (PCA) and spectral correlation measure (SCM); PCA emphasizes the amount of information in band combinations, while SCM focuses on correlation between bands. The results show that the true-color 3D imaging can be realized based on HSL measurements, and three spectral bands of 466, 546, and 626 nm were determined. Comparing reflectance of the three selected bands, the overall classification accuracy of seven different colored objects was improved by 14.6% and 8.25% based on SVM and NB, respectively, classifiers after converting spectral intensities into true-color information. Overall, this study demonstrated the potential of HSL system in retrieving true-color and facilitating target recognition, and can serve as a guide in developing future three-channel or multi-channel true-color LiDAR.

Offline and online myoelectric pattern recognition analysis and real-time control of a robotic hand after spinal cord injury

Objective. The objective of this study was to investigate the feasibility of applying myoelectric pattern recognition for controlling a robotic hand in individuals with spinal cord injury (SCI). Approach. Surface electromyogram (sEMG) signals of six hand motion patterns were recorded from 12 subjects with SCI. Online and offline classification performance of two classifiers (Gaussian Naive Bayes classifier, GNB, and support vector machine, SVM) were investigated. An exoskeleton hand was then controlled in real-time using the classification results. The control accuracy and its correlation with function assessments were investigated. Main results. Average offline classification accuracy of all tested SCI subjects was (73.6 ± 14.0)% for GNB and (77.6 ± 11.6)% for SVM, respectively. Average online classification accuracy was significantly lower, (64.3 ± 15.0)% for GNB and (70.2 ± 13.2)% for SVM. Average control accuracy of (81.0 ± 16.3)% was achieved in real-time control of the robotic hand using myoelectric pattern recognition. Correlation between control accuracy and grip/pinch force was observed. Significance. The results show that it is feasible to extract hand motion intent from individuals with SCI and control a robotic hand device using myoelectric pattern recognition. The performance of real-time control can be predicted based on functional assessments.

Network Intrusion Detection Method Based on PCA and Bayes Algorithm

Intrusion detection refers to monitoring network data information, quickly detecting intrusion behavior, can avoid the harm caused by intrusion to a certain extent. Traditional intrusion detection methods are mainly focused on rule files and data mining. They have the disadvantage of not being able to detect new types of attacks and have the slow detection speed. To address these issues, an intrusion detection method based on improved PCA combined with Gaussian Naive Bayes was proposed. By weighting the first few feature vectors of the traditional PCA, data pollution can be reduced. The number of final weighted principal components is 2 through sequential selection. The dimensionality reduction of the data is achieved through improved PCA. Finally, the intrusion behaviors were detected by using the Gaussian Naive Bayes classifier. The indexes of detection accuracy, detection time, precision rate, and recall rate were applied to evaluate the results. The experimental results show that, comparing with the traditional Bayes method, the method proposed in this article can reduce the detection time by 60%, shorten it to 0.5s, and increase the detection rate to 91.06%. The mean value of detection accuracy is about 86% by cross-validation.

Lung Consolidation Detection through Analysis of Vocal Resonance Signals.

Consolidation of the lung is a common pathology which is sometimes life threatening. One of the primary causes is the infection of lung tissue (pneumonia). Vocal resonance and vocal fremitus are part of the routine clinical examination of the respiratory system by physicians, which although time consuming, helps in the diagnosis of consolidation of the lung. In this paper, we suggest a possible automatic lung consolidation detection system that can be used by health workers with basic training. Analysis is performed on the vocal resonance sound signals recorded using an electronic stethoscope from the chest walls of normal subjects and patients. We show that for the detection system, use of signal loudness, which is generally considered by physicians, would be infeasible and propose that signal power spectral density computed using our system be considered. Certain frequency regions in the power spectral density (periodogram) are proved to be significant indicators of lung consolidation using t-tests. These findings are then applied to design the detection system using Gaussian naive Bayes classifiers.

An improved model based on genetic algorithm for detecting intrusion in mobile ad hoc network

In any data communication between networks, it is very essential to maintain a high level of security to make sure that the data communication is safe and trusted. There may be chance for intrusions and misuses of information in a network. Intrusion detection systems (IDSs) has become an important component in terms of computer and network security. Detection can be host based or network based. The existing approaches being utilized in intrusion detection are not efficient. This paper presents a genetic algorithm based IDS to detect the malicious nodes in the network. Cloud computing understands users in network nodes in ad hoc or fixed manner to have long term connectivity for service utilization. The proposed approach performs better compared to Gaussian Naive Bayes classifier approach. The objective value of chromosome is calculated through a set of iterations. The experimental results show that the computation time is reduced with high successful detection and network performance is improved to provide reliable transmission. The model is also suitable for users on cloud framework.

Fast Gaussian Naïve Bayes for searchlight classification analysis

The searchlight technique is a variant of multivariate pattern analysis (MVPA) that examines neural activity across large sets of small regions, exhaustively covering the whole brain. This usually involves application of classifier algorithms across all searchlights, which entails large computational costs especially when testing the statistical significance of the accuracies with permutation methods. In this article, a new implementation of the Gaussian Naive Bayes classifier is presented (henceforth massive-GNB). This approach allows classification in all searchlights simultaneously, and is faster than previously published searchlight GNB implementations, as well as other more complex classifiers including support vector machines (SVM). To ensure that the gain in speed for GNB would be useful in searchlight analysis, we compared the accuracies of massive-GNB and SVM in detecting the lateral occipital complex (LOC) in an fMRI localizer experiment (26 subjects). Moreover, this region as defined in a meta-analysis of many activation studies was used as a gold standard to compare error rates for both classifiers. In individual searchlights, SVM was somewhat more accurate than massive-GNB and more selective in detecting the meta-analytic LOC. However, with multiple comparison correction at the cluster-level the two classifiers performed equivalently. Thus for cluster-level analysis, massive-GNB produces an accuracy similar to more sophisticated classifiers but with a substantial gain in speed. Massive-GNB (available as a public Matlab toolbox) could facilitate the more widespread use of searchlight analysis.

RGNBC: Rough Gaussian Naïve Bayes Classifier for Data Stream Classification with Recurring Concept Drift

Due to the necessity of performing classification in streaming environments, researchers have developed various stream classification methods by handling concept drift. But, recurring concept drift is a challenging problem in data stream as the dimension of the data is not static over the period of time. By considering the recurring concept drift, this paper proposes a new classifier model, called Rough Gaussian Naive Bayes Classifier (RGNBC) for the data stream classification. Here, two new contributions are made to handle the challenges of recurring concept drift. The first contribution is to utilize the rough set theory for detecting the concept drift. Then, gaussian naive classifier is modified mathematically to handle the dynamic data without using the historic data. Also, the classification is performed using the posterior probability and the objective function which considers the multiple criteria. The proposed RGNBC model is experimented with two large datasets, and the results are validated against the existing MReC-DFS algorithm using sensitivity, specificity and accuracy. From the results, we proved that the proposed RGNBC model obtained the maximum accuracy of 74.5 % while compared with the existing algorithm.

On User-Centric Modular QoE Prediction for VoIP Based on Machine-Learning Algorithms

The impact of the network performance on the quality of experience (QoE) for various services is not well-understood. Assessing the impact of different network and channel conditions on the user experience is important for improving the telecommunication services. The QoE for various wireless services including VoIP, video streaming, and web browsing, has been in the epicenter of recent networking activities. The majority of such efforts aim to characterize the user experience, analyzing various types of measurements often in an aggregate manner. This paper proposes the MLQoE, a modular algorithm for user-centric QoE prediction. The MLQoE employs multiple machine learning (ML) algorithms, namely, Artificial Neural Networks, Support Vector Regression machines, Decision Trees, and Gaussian Naive Bayes classifiers, and tunes their hyper-parameters. It uses the Nested Cross Validation (nested CV) protocol for selecting the best classifier and the corresponding best hyper-parameter values and estimates the performance of the final model. The MLQoE is conservative in the performance estimation despite multiple induction of models. The MLQoE is modular, in that, it can be easily extended to include other ML algorithms. The MLQoE selects the ML algorithm that exhibits the best performance and its parameters automatically given the dataset used as input. It uses empirical measurements based on network metrics (e.g., packet loss, delay, and packet interarrival) and subjective opinion scores reported by actual users. This paper extensively evaluates the MLQoE using three unidirectional datasets containing VoIP calls over wireless networks under various network conditions and feedback from subjects (collected in field studies). Moreover, it performs a preliminary analysis to assess the generality of our methodology using bidirectional VoIP and video traces. The MLQoE outperforms several state-of-the-art algorithms, resulting in fairly accurate predictions.

Anticipative Hybrid Extreme Rotation Forest

This paper introduces an improvement on the recently published Hybrid Extreme Rotation Forest (HERF), consisting in the anticipative determination of the the fraction of each classifier architecture included in the ensemble. We call it AHERF. Both HERF and AHERF are heterogeneous classifier ensembles, which aim to profit from the diverse problem domain specificities of each classifier architecture in order to achieve improved generalization over a larger spectrum of problem domains. In this paper AHERF are built from a pool of Decision Trees (DT), Extreme Learning Machines (ELM), Support Vector Machines (SVM), k-Nearest Neighbors (k-NN), Adaboost, Random Forests (RF), and Gaussian Naive Bayes (GNB) classifiers. Given a problem dataset, the process of anticipative determination of the ensemble composition is as follows: First, we estimate the performance of each classifier architecture by independent pilot cross-validation experiments on a small subsample of the data. Next, classifier architectures are ranked according to their accuracy results. A probability distribution of classifier architectures appearing in the ensemble is built from this ranking. Finally, the type of each individual classifier is decided by sampling this probability distribution. Computational experiments on a collection of benchmark classification problems shows improvement on the original HERF, and other state-of-the-art approaches.

Naive Bayes vs Logistic Regression: Theory, Implementation and Experimental Validation

This article presents the theoretical derivation as well as practical steps for implementing Naive Bayes (NB) and Logistic Regression (LR) classifiers. A generative learning under Gaussian Naive Bayes assumption and two discriminative learning techniques based on gradient ascent and Newton-Raphson methods are described to estimate the parameters of LR. Some limitation of learning techniques and implementation issues are discussed as well. A set of experiments are performed for both the classifiers under different learning circumstances and their performances are compared. From the experiments, it is observed that LR learning with gradient ascent technique outperforms general NB classifier. However, under Gaussian Naive Bayes assumption, both classifiers NB and LR perform similar.

Pattern classification of fMRI data: Applications for analysis of spatially distributed cortical networks

The field of fMRI data analysis is rapidly growing in sophistication, particularly in the domain of multivariate pattern classification. However, the interaction between the properties of the analytical model and the parameters of the BOLD signal (e.g. signal magnitude, temporal variance and functional connectivity) is still an open problem. We addressed this problem by evaluating a set of pattern classification algorithms on simulated and experimental block-design fMRI data. The set of classifiers consisted of linear and quadratic discriminants, linear support vector machine, and linear and nonlinear Gaussian naive Bayes classifiers. For linear discriminant, we used two methods of regularization: principal component analysis, and ridge regularization. The classifiers were used (1) to classify the volumes according to the behavioral task that was performed by the subject, and (2) to construct spatial maps that indicated the relative contribution of each voxel to classification. Our evaluation metrics were: (1) accuracy of out-of-sample classification and (2) reproducibility of spatial maps. In simulated data sets, we performed an additional evaluation of spatial maps with ROC analysis. We varied the magnitude, temporal variance and connectivity of simulated fMRI signal and identified the optimal classifier for each simulated environment. Overall, the best performers were linear and quadratic discriminants (operating on principal components of the data matrix) and, in some rare situations, a nonlinear Gaussian naïve Bayes classifier. The results from the simulated data were supported by within-subject analysis of experimental fMRI data, collected in a study of aging. This is the first study that systematically characterizes interactions between analysis model and signal parameters (such as magnitude, variance and correlation) on the performance of pattern classifiers for fMRI.

A multi-voxel-activity-based feature selection method for human cognitive states classification by functional magnetic resonance imaging data

Nowadays, various kinds of signals and data were collected to investigate human brain's activities for disease detection. In particular, the functional magnetic resonance imaging (fMRI) provides a powerful tool for enquiring the brain functions. Learning the activity patterns that are related to the specific cognitive states from fMRI data is one of the most critical challenges for neuroscientists. The high dimensional property and noises make fMRI data become difficulty for mining and unfamiliar with conventional approaches. In this paper, we propose a new feature selection method for classifying human cognitive states from fMRI data. The fisher discriminant ratio (FDR) between classes and zero condition is used to measure the activity of voxels. We then choose the most active voxels from the most active regions of interest (ROIs) as the most informative features for Gaussian naive bayes (GNB) classifier. The proposed method can be used to boost the whole system because it will exclude the non-task-related components and therefore, reduce the processing time and increase the accuracy. The StarPlus dataset and Visual object recognition dataset are used to investigate the performance of the proposed method. The experimental results show that our proposed method has better performance compared to other systems. The accuracy is $$\sim $$ ~ 96.45 % for StarPlus dataset and 88.4 % for Visual Object Recognition dataset.

Smoothness without Smoothing: Why Gaussian Naive Bayes Is Not Naive for Multi-Subject Searchlight Studies

Spatial smoothness is helpful when averaging fMRI signals across multiple subjects, as it allows different subjects' corresponding brain areas to be pooled together even if they are slightly misaligned. However, smoothing is usually not applied when performing multivoxel pattern-based analyses (MVPA), as it runs the risk of blurring away the information that fine-grained spatial patterns contain. It would therefore be desirable, if possible, to carry out pattern-based analyses which take unsmoothed data as their input but which produce smooth images as output. We show here that the Gaussian Naive Bayes (GNB) classifier does precisely this, when it is used in “searchlight” pattern-based analyses. We explain why this occurs, and illustrate the effect in real fMRI data. Moreover, we show that analyses using GNBs produce results at the multi-subject level which are statistically robust, neurally plausible, and which replicate across two independent data sets. By contrast, SVM classifiers applied to the same data do not generate a replication, even if the SVM-derived searchlight maps have smoothing applied to them. An additional advantage of GNB classifiers for searchlight analyses is that they are orders of magnitude faster to compute than more complex alternatives such as SVMs. Collectively, these results suggest that Gaussian Naive Bayes classifiers may be a highly non-naive choice for multi-subject pattern-based fMRI studies.

A neural decoding approach to auditory temporal assimilation

By constructing Gaussian Naive Bayes Classifiers, we have re-analyzed data from an earlier event-related potential (ERP) study of an illusion in time perception known as auditory temporal assimilation. In auditory temporal assimilation, two neighboring physically unequal time intervals marked by three successive tone bursts are illusorily perceived as equal if the two time intervals satisfy a certain relationship. The classifiers could discriminate whether or not the subject was engaged in the task, which was judgment of the subjective equality between the two intervals, at an accuracy of >79%, and from principal component scores of individual average ERP waveforms, we were able to predict their subjective judgments to each stimulus at an accuracy of >70%. Chernoff information, unlike accuracy or Kullback–Leibler (KL) distance, suggested brain activation associated with auditory temporal assimilation at an early pre-decision stage. This may provide us with a simple and useful neural decoding scheme in analyzing information processing of temporal patterns in the brain.

A Communication Perspective on Automatic Text Categorization

The basic concern of a Communication System is to transfer information from its source to a destination some distance away. Textual documents also deal with the transmission of information. Particularly, from a text categorization system point of view, the information encoded by a document is the topic or category it belongs to. Following this initial intuition, a theoretical framework is developed where Automatic Text Categorization(ATC) is studied under a Communication System perspective. Under this approach, the problematic indexing feature space dimensionality reduction has been tackled by a two-level supervised scheme, implemented by a noisy terms filtering and a subsequent redundant terms compression. Gaussian probabilistic categorizers have been revisited and adapted to the concomitance of sparsity in ATC. Experimental results pertaining to 20 Newsgroups and Reuters-21578 collections validate the theoretical approaches. The noise filter and redundancy compressor allows an aggressive term vocabulary reduction (reduction factor greater than 0.99) with a minimum loss (lower than 3 percent) and, in some cases, gain (greater than 4 percent) of final classification accuracy. The adapted Gaussian Naive Bayes classifier reaches classification results similar to those obtained by state-of-the-art Multinomial Naive Bayes (MNB) and Support Vector Machines (SVMs).