Classifiers In Terms Of Performance Research Articles

Classification of EEG Using Adaptive SVM Classifier with CSP and Online Recursive Independent Component Analysis.

An efficient feature extraction method for two classes of electroencephalography (EEG) is demonstrated using Common Spatial Patterns (CSP) with optimal spatial filters. However, the effects of artifacts and non-stationary uncertainty are more pronounced when CSP filtering is used. Furthermore, traditional CSP methods lack frequency domain information and require many input channels. Therefore, to overcome this shortcoming, a feature extraction method based on Online Recursive Independent Component Analysis (ORICA)-CSP is proposed. For EEG-based brain—computer interfaces (BCIs), especially online and real-time BCIs, the most widely used classifiers used to be linear discriminant analysis (LDA) and support vector machines (SVM). Previous evaluations clearly show that SVMs generally outperform other classifiers in terms of performance. In this case, Adaptive Support Vector Machine (A-SVM) is used for classification together with the ORICA-CSP method. The results are promising, and the experiments are performed on EEG data of 4 classes’ motor images, namely Dataset 2a of BCI Competition IV.

Machine learning techniques for code smell detection: A systematic literature review and meta-analysis

Abstract Background: Code smells indicate suboptimal design or implementation choices in the source code that often lead it to be more change- and fault-prone. Researchers defined dozens of code smell detectors, which exploit different sources of information to support developers when diagnosing design flaws. Despite their good accuracy, previous work pointed out three important limitations that might preclude the use of code smell detectors in practice: (i) subjectiveness of developers with respect to code smells detected by such tools, (ii) scarce agreement between different detectors, and (iii) difficulties in finding good thresholds to be used for detection. To overcome these limitations, the use of machine learning techniques represents an ever increasing research area. Objective: While the research community carefully studied the methodologies applied by researchers when defining heuristic-based code smell detectors, there is still a noticeable lack of knowledge on how machine learning approaches have been adopted for code smell detection and whether there are points of improvement to allow a better detection of code smells. Our goal is to provide an overview and discuss the usage of machine learning approaches in the field of code smells. Method: This paper presents a Systematic Literature Review (SLR) on Machine Learning Techniques for Code Smell Detection. Our work considers papers published between 2000 and 2017. Starting from an initial set of 2456 papers, we found that 15 of them actually adopted machine learning approaches. We studied them under four different perspectives: (i) code smells considered, (ii) setup of machine learning approaches, (iii) design of the evaluation strategies, and (iv) a meta-analysis on the performance achieved by the models proposed so far. Results: The analyses performed show that God Class, Long Method, Functional Decomposition, and Spaghetti Code have been heavily considered in the literature. Decision Trees and Support Vector Machines are the most commonly used machine learning algorithms for code smell detection. Models based on a large set of independent variables have performed well. JRip and Random Forest are the most effective classifiers in terms of performance. The analyses also reveal the existence of several open issues and challenges that the research community should focus on in the future. Conclusion: Based on our findings, we argue that there is still room for the improvement of machine learning techniques in the context of code smell detection. The open issues emerged in this study can represent the input for researchers interested in developing more powerful techniques.

A Decision Tree and Naïve Bayes algorithm for income tax prediction

One of the concerns regarding the tax collection system is incorrect case selection. Manual selection of audit cases by auditors (whose role is to detect individual cases of tax non-compliance) based on their expert knowledge of the taxpayers’ behaviour, cannot uncover all patterns of non-compliant behaviour hidden in historical data. In addition, random selection of audit cases is not focused on the highest risks. In other words, manual selection has a high opportunity cost if it is used as the sole selection method. Computational intelligence provides methods, techniques and tools, which have been taught to automatically make accurate income tax predictions based on past observations. The data were retrieved from the real time environmental situation. Application of computational intelligence methods proved to be efficient in learning a classification algorithm to classify compliant and non-compliant taxpayers. The new algorithm was evaluated and validated in empirical tests on the same dataset. Although this algorithm had the same performance measurement as Bagging, it outperformed the other existing multiple classifiers in terms of performance. This illustrates an automated system that replicates the investigative operation of human tax risk auditors.

A novel online multi-label classifier for high-speed streaming data applications

In this paper, a high-speed online neural network classifier based on extreme learning machines for multi-label classification is proposed. In multi-label classification, each of the input data sample belongs to one or more than one of the target labels. The traditional binary and multi-class classification where each sample belongs to only one target class forms the subset of multi-label classification. Multi-label classification problems are far more complex than binary and multi-class classification problems, as both the number of target labels and each of the target labels corresponding to each of the input samples are to be identified. The proposed work exploits the high-speed nature of the extreme learning machines to achieve real-time multi-label classification of streaming data. A new threshold-based online sequential learning algorithm is proposed for high speed and streaming data classification of multi-label problems. The proposed method is experimented with six different datasets from different application domains such as multimedia, text, and biology. The hamming loss, accuracy, training time and testing time of the proposed technique is compared with nine different state-of-the-art methods. Experimental studies shows that the proposed technique outperforms the existing multi-label classifiers in terms of performance and speed.

A second-order cone programming formulation for twin support vector machines

Second-order cone programming (SOCP) formulations have received increasing attention as robust optimization schemes for Support Vector Machine (SVM) classification. These formulations study the worst-case setting for class-conditional densities, leading to potentially more effective classifiers in terms of performance compared to the standard SVM formulation. In this work we propose an SOCP extension for Twin SVM, a recently developed classification approach that constructs two nonparallel classifiers. The linear and kernel-based SOCP formulations for Twin SVM are derived, while the duality analysis provides interesting geometrical properties of the proposed method. Experiments on benchmark datasets demonstrate the virtues of our approach in terms of classification performance compared to alternative SVM methods.

Finding a short and accurate decision rule in disjunctive normal form by exhaustive search

Greedy approaches suffer from a restricted search space which could lead to suboptimal classifiers in terms of performance and classifier size. This study discusses exhaustive search as an alternative to greedy search for learning short and accurate decision rules. The Exhaustive Procedure for LOgic-Rule Extraction (EXPLORE) algorithm is presented, to induce decision rules in disjunctive normal form (DNF) in a systematic and efficient manner. We propose a method based on subsumption to reduce the number of values considered for instantiation in the literals, by taking into account the relational operator without loss of performance. Furthermore, we describe a branch-and-bound approach that makes optimal use of user-defined performance constraints. To improve the generalizability we use a validation set to determine the optimal length of the DNF rule. The performance and size of the DNF rules induced by EXPLORE are compared to those of eight well-known rule learners. Our results show that an exhaustive approach to rule learning in DNF results in significantly smaller classifiers than those of the other rule learners, while securing comparable or even better performance. Clearly, exhaustive search is computer-intensive and may not always be feasible. Nevertheless, based on this study, we believe that exhaustive search should be considered an alternative for greedy search in many problems.

A fast linear-in-the-parameters classifier construction algorithm using orthogonal forward selection to minimize leave-one-out misclassification rate

We propose a simple and computationally efficient construction algorithm for two class linear-in-the-parameters classifiers. In order to optimize model generalization, a forward orthogonal selection (OFS) procedure is used for minimizing the leave-one-out (LOO) misclassification rate directly. An analytic formula and a set of forward recursive updating formula of the LOO misclassification rate are developed and applied in the proposed algorithm. Numerical examples are used to demonstrate that the proposed algorithm is an excellent alternative approach to construct sparse two class classifiers in terms of performance and computational efficiency.