Online streaming feature selection using adapted Neighborhood Rough Set

Multi-Label Attribute Reduction Based on Neighborhood Multi-Target Rough Sets

The rough set model has two symmetry approximations called upper approximation and lower approximation, which correspond to a concept’s intension and extension, respectively. Multi-label learning enforces the rough set model, which wants to be applied considering the correlations among labels, while the target concept should not be limited to only one. This paper proposes a multi-target model considering label correlation (Neighborhood Multi-Target Rough Sets, NMTRS) and proposes an attribute reduction approach based on NMTRS. First, some definitions of NMTRS are introduced. Second, some properties of NMTRS are discussed. Third, some discussion about the attribute significance measure is given. Fourth, the attribute reduction approaches based on NMTRS are proposed. Finally, the efficiency and validity of the designed algorithms are verified by experiments. The experiments show that our algorithm shows considerable performance when compared to state-of-the-art approaches.

Online group streaming feature selection using entropy-based uncertainty measures for fuzzy neighborhood rough sets

Online group streaming feature selection, as an essential online processing method, can deal with dynamic feature selection tasks by considering the original group structure information of the features. Due to the fuzziness and uncertainty of the feature stream, some existing methods are unstable and yield low predictive accuracy. To address these issues, this paper presents a novel online group streaming feature selection method (FNE-OGSFS) using fuzzy neighborhood entropy-based uncertainty measures. First, a separability measure integrating the dependency degree with the coincidence degree is proposed and introduced into the fuzzy neighborhood rough sets model to define a new fuzzy neighborhood entropy. Second, inspired by both algebra and information views, some fuzzy neighborhood entropy-based uncertainty measures are investigated and some properties are derived. Furthermore, the optimal features in the group are selected to flow into the feature space according to the significance of features, and the features with interactions are left. Then, all selected features are re-evaluated by the Lasso model to discard the redundant features. Finally, an online group streaming feature selection algorithm is designed. Experimental results compared with eight representative methods on thirteen datasets show that FNE-OGSFS can achieve better comprehensive performance.

Label-specific guidance for efficiently searching reduct

In the era of big data for exploring attribute reduction/rough set-based feature selection related problems, to design efficient strategies for deriving reducts and then reduce the dimensions of data, two fundamental perspectives of Granular Computing may be taken into account: breaking up the whole into pieces and gathering parts into a whole. From this point of view, a novel strategy named label-specific guidance is introduced into the process of searching reduct. Given a formal description of attribute reduction, by considering the corresponding constraint, we divide it into several label-specific based constraints. Consequently, a sequence of these label-specific based constraints can be obtained, it follows that the reduct related to the previous label-specific based constraint may have guidance on the computation of that related to the subsequent label-specific based constraint. The thinking of this label-specific guidance runs through the whole process of searching reduct until the reduct over the whole universe is derived. Compared with five state-of-the-art algorithms over 20 data sets, the experimental results demonstrate that our proposed acceleration strategy can not only significantly accelerate the process of searching reduct but also offer justifiable performance in the task of classification. This study suggests a new trend concerning the problem of quickly deriving reduct.

Fuzzy Rank Based Parallel Online Feature Selection Method using Multiple Sliding Windows

Nowadays, in real-world applications, the dimensions of data are generated dynamically, and the traditional batch feature selection methods are not suitable for streaming data. So, online streaming feature selection methods gained more attention but the existing methods had demerits like low classification accuracy, fails to avoid redundant and irrelevant features, and a higher number of features selected. In this paper, we propose a parallel online feature selection method using multiple sliding-windows and fuzzy fast-mRMR feature selection analysis, which is used for selecting minimum redundant and maximum relevant features, and also overcomes the drawbacks of existing online streaming feature selection methods. To increase the performance speed of the proposed method parallel processing is used. To evaluate the performance of the proposed online feature selection method k-NN, SVM, and Decision Tree Classifiers are used and compared against the state-of-the-art online feature selection methods. Evaluation metrics like Accuracy, Precision, Recall, F1-Score are used on benchmark datasets for performance analysis. From the experimental analysis, it is proved that the proposed method has achieved more than 95% accuracy for most of the datasets and performs well over other existing online streaming feature selection methods and also, overcomes the drawbacks of the existing methods.

Adaptive Quick Reduct for Feature Drift Detection

Data streams are ubiquitous and related to the proliferation of low-cost mobile devices, sensors, wireless networks and the Internet of Things. While it is well known that complex phenomena are not stationary and exhibit a concept drift when observed for a sufficiently long time, relatively few studies have addressed the related problem of feature drift. In this paper, a variation of the QuickReduct algorithm suitable to process data streams is proposed and tested: it builds an evolving reduct that dynamically selects the relevant features in the stream, removing the redundant ones and adding the newly relevant ones as soon as they become such. Tests on five publicly available datasets with an artificially injected drift have confirmed the effectiveness of the proposed method.

New Online Streaming Feature Selection Based on Neighborhood Rough Set for Medical Data

Not all features in many real-world applications, such as medical diagnosis and fraud detection, are available from the start. They are formed and individually flow over time. Online streaming feature selection (OSFS) has recently attracted much attention due to its ability to select the best feature subset with growing features. Rough set theory is widely used as an effective tool for feature selection, specifically the neighborhood rough set. However, the two main neighborhood relations, namely k-neighborhood and neighborhood, cannot efficiently deal with the uneven distribution of data. The traditional method of dependency calculation does not take into account the structure of neighborhood covering. In this study, a novel neighborhood relation combined with k-neighborhood and neighborhood relations is initially defined. Then, we propose a weighted dependency degree computation method considering the structure of the neighborhood relation. In addition, we propose a new OSFS approach named OSFS-KW considering the challenge of learning class imbalanced data. OSFS-KW has no adjustable parameters and pretraining requirements. The experimental results on 19 datasets demonstrate that OSFS-KW not only outperforms traditional methods but, also, exceeds the state-of-the-art OSFS approaches.