Learning to hash is of particular interest in information retrieval for large-scale data due to its high efficiency and effectiveness. Most studies in hashing concentrate on constructing new hashing models, but rarely touch the correlation and redundancy between hash bits derived. In this article, we first introduce a general schema of hash bit reduction to derive compact and informative binary codes for hashing techniques. Further, we take locality sensitive hashing, one of the most widely-used hashing methods, as an example and propose a novel and two-stage binary code refinement method under the reduction schema. Specifically, the proposed method includes two stages, i.e., bit evaluation and bit refinement. The former stage aims to initially extract a small portion of informative hash bits in terms of their importance and quality evaluated by bit balance and similarity preservation. Then, the representation capabilities of the reduced hash bits are strengthened further by refining their binary values. The purpose of refinement is to lessen the correlations and redundancies between the reduced bits, making themselves more discriminative. The experimental results on three widely-used data collections confirm the effectiveness of the proposed bit reduction method and its superiority over the state-of-the-art hashing methods, as well as a bit selection method.

Similarity representation plays a central role in increasingly popular anomaly detection techniques, which have been successfully applied in various realistic scenes. Until now, many low-rank representation techniques have been introduced to measure the similarity relations of data; yet, they only concern to minimize reconstruction errors, without involving the structural information of data. Besides, the traditional low-rank representation methods often take nuclear norm as their low-rank constraints, easily yielding a suboptimal solution. To address the problems above, in this article, we propose a novel anomaly detection method, which exploits kernel preserving embedding, as well as the double nuclear norm, to explore the similarity relations of data. Based on the similarity relations, a kind of probability transition matrix is derived, and a tailored random walk is further adopted to reveal anomalies. The proposed method can not only preserve the manifold structural properties of the data, but also alleviate the suboptimal problem. To validate the superiority of our method, extensive experiments with eight popular anomaly detection algorithms were conducted on 12 widely used datasets. The experimental results show that our detection method outperformed the state-of-the-art anomaly detection algorithms in most cases.

In this paper, we characterize all weakly smooth uninorms (i.e., uninorms with smooth underlying operators) defined on a finite chain. It is proved that any such uninorm is determined by three unary functions and vice versa. As a by-product, we obtain the characterizations of smooth t-norms, smooth t-conorms through additive generators and show that on a finite chain, there exists no counterpart of the class of uninorms continuous in ]0, 1[2.

Multi-label learning has attracted an increasing attention from many domains, because of its great potential applications. Although many learning methods have been witnessed, two major challenges are still not handled very well. They are the correlations and the high dimensionality of data. In this paper, we exploit the inherent property of the multi-label data and propose an effective sparse multi-label learning algorithm. Specifically, it handles the high-dimensional multi-label data by using a regularized partial least squares discriminant analysis with a l1-norm penalty. Consequently, the proposed method can not only capture the label correlations effectively, but also perform the operation of dimensionality reduction at the same time. The experimental results conducted on eight public data sets show that our method is promising and outperformed the state-of-the-art multi-label classifiers in most cases.

One class of fuzzy implications is introduced by means of the additive generators of continuous Archimedean t-norms. Basic properties of these implications are discussed. These implications are shown to be different from the known (S,N)-, R-, QL-, and Yager's f- and g-implications. Several functional equations with fuzzy implications are investigated. © 2012 Wiley Periodicals, Inc.

One of the challenges in data mining is the dimensionality of data, which is often very high and prevalent in many domains, such as text categorization and bio-informatics. The high-dimensionality of data may bring many adverse situations to traditional learning algorithms. To cope with this issue, feature selection has been put forward. Currently, many efforts have been attempted in this field and lots of feature selection algorithms have been developed. In this paper we propose a new selection method to pick discriminative features by using information measurement. The main characteristic of our selection method is that the selection procedure works like feature clustering in a hierarchically agglomerative way, where each feature is considered as a cluster and the between-cluster and within-cluster distances are measured by mutual information and the coefficient of relevancy respectively. Consequently, the final aggregated cluster is the selection result, which has the minimal redundancy among its members and the maximal relevancy with the class labels. The simulation experiments on seven datasets show that the proposed method outperforms other popular feature selection algorithms in classification performance.