Showing papers on "Classifier chains published in 2014"

A Review On Multi-Label Learning Algorithms

Abstract: Multi-label learning studies the problem where each example is represented by a single instance while associated with a set of labels simultaneously. During the past decade, significant amount of progresses have been made toward this emerging machine learning paradigm. This paper aims to provide a timely review on this area with emphasis on state-of-the-art multi-label learning algorithms. Firstly, fundamentals on multi-label learning including formal definition and evaluation metrics are given. Secondly and primarily, eight representative multi-label learning algorithms are scrutinized under common notations with relevant analyses and discussions. Thirdly, several related learning settings are briefly summarized. As a conclusion, online resources and open research problems on multi-label learning are outlined for reference purposes.

On the Problem of Error Propagation in Classifier Chains for Multi-label Classification

Abstract: So-called classifier chains have recently been proposed as an appealing method for tackling the multi-label classification task. In this paper, we analyze the influence of a potential pitfall of the learning process, namely the discrepancy between the feature spaces used in training and testing: while true class labels are used as supplementary attributes for training the binary models along the chain, the same models need to rely on estimations of these labels when making a prediction. We provide first experimental results suggesting that the attribute noise thus created can affect the overall prediction performance of a classifier chain.

A Deep Interpretation of Classifier Chains

Abstract: In the “classifier chains” (CC) approach for multi-label classification, the predictions of binary classifiers are cascaded along a chain as additional features. This method has attained high predictive performance, and is receiving increasing analysis and attention in the recent multi-label literature, although a deep understanding of its performance is still taking shape. In this paper, we show that CC gets predictive power from leveraging labels as additional stochastic features, contrasting with many other methods, such as stacking and error correcting output codes, which use label dependence only as kind of regularization. CC methods can learn a concept which these cannot, even supposing the same base classifier and hypothesis space. This leads us to connections with deep learning (indeed, we show that CC is competitive precisely because it is a deep learner), and we employ deep learning methods – showing that they can supplement or even replace a classifier chain. Results are convincing, and throw new insight into promising future directions.

Distinct chains for different instances: an effective strategy for multi-label classifier chains

Abstract: Multi-label classification (MLC) is a predictive problem in which an object may be associated with multiple labels. One of the most prominent MLC methods is the classifier chains (CC). This method induces q binary classifiers, where q represents the number of labels. Each one is responsible for predicting a specific label. These q classifiers are linked in a chain, such that at classification time each classifier considers the labels predicted by the previous ones as additional information. Although the performance of CC is largely influenced by the chain ordering, the original method uses a random ordering. To cope with this problem, in this paper we propose a novel method which is capable of finding a specific and more effective chain for each new instance to be classified. Experiments have shown that the proposed method obtained, overall, higher predictive accuracies than the well-established binary relevance, CC and CC ensemble methods.

Trading off Speed and Accuracy in Multilabel Classification

Abstract: In previous work, we devised an approach for multilabel classification based on an ensemble of Bayesian networks. It was characterized by an efficient structural learning and by high accuracy. Its shortcoming was the high computational complexity of the MAP inference, necessary to identify the most probable joint configuration of all classes. In this work, we switch from the ensemble approach to the single model approach. This allows important computational savings. The reduction of inference times is exponential in the difference between the treewidth of the single model and the number of classes. We adopt moreover a more sophisticated approach for the structural learning of the class subgraph. The proposed single models outperforms alternative approaches for multilabel classification such as binary relevance and ensemble of classifier chains.

Method for semantically annotating images on basis of hybrid generative and discriminative learning models

Abstract: The invention discloses a method for semantically annotating images on the basis of hybrid generative and discriminative learning models. The method includes generatively building models of the images by means of continuous PLSA (probabilistic latent semantic analysis) at generative learning stages, acquiring corresponding model parameters and subject distribution of each image, and utilizing the corresponding subject distribution as an intermediate representation vector of each image; constructing cluster classifier chains to discriminatively learn from the intermediate representation vectors of the images at discriminative learning stages, creating the classifier chains and integrating contextual information among annotation keywords; automatically extracting visual features of each given unknown image at annotation stages, acquiring representation of subject vectors of the given unknown images by the aid of a continuous PLSA parameter estimation algorithm, classifying the subject vectors by the aid of trained cluster classifier chains and semantically annotating the images by a plurality of semantic keywords with the highest confidence. The method has the advantage that the annotation and retrieval performance of the method are superior to the annotation and retrieval performance of most current typical methods for automatically annotating images.

A Performance Comparison of Multi-Label Classification Methods for Protein Subcellular Localization Prediction

Abstract: This paper presents an extensive experimental comparison of a variety of multi-label learning methods for the accurate prediction of subcellular localization of proteins which simultaneously exist at multiple subcellular locations. We compared several methods from three categories of multi-label classification algorithms: algorithm adaptation, problem transformation, and meta learning. Experimental results are analyzed using 12 multi-label evaluation measures to assess the behavior of the methods from a variety of view-points. We also use a new summarization measure to find the best performing method. Experimental results show that the best performing methods are power-set method pruning a infrequently occurring subsets of labels and classifier chains modeling relevant labels with an additional feature. futhermore, ensembles of many classifiers of these methods enhance the performance further. The recommendation from this study is that the correlation of subcellular locations is an effective clue for classification, this is because the subcellular locations of proteins performing certain biological function are not independent but correlated.

Sélection d'une méthode de classification multi-label pour un système interactif

Abstract: The objective of this paper is to evaluate the ability of 12 multi-label classification algorithms at learning, in a short time, with few training examples. Experimental results highlight significant differences for 3 selected evaluation measures: Log-Loss, Ranking-Loss, Learning/Prediction time, and the best results are obtained with: Multi-label k Nearest neighbors (ML-kNN ), followed by Ensemble of Classifier Chains (ECC) and Ensemble of Binary Relevance (EBR).