Pattern Recognition and Image Analysis

Diffuse Liver Disease Classification from Ultrasound Surface Characterization, Clinical and Laboratorial Data (Pattern Recognition and Image Analysis)

Abstract In this work liver contour is semi-automatically segmented and quantified in order to help the identification and diagnosis of diffuse liver disease. The features extracted from the liver contour are jointly used with clinical and laboratorial data in the staging process. The classification results of a support vector machine, a Bayesian and a k-nearest […]

Classification of Ultrasound Medical Images Using Distance Based Feature Selection and Fuzzy-SVM (Pattern Recognition and Image Analysis)

Abstract This paper presents a method of classifying ultrasound medical images towards dealing with two important aspects: (i) optimal feature subset selection for representing ultrasound medical images and (ii) improvement of classification accuracy by avoiding outliers. An objective function combining the concept of between-class distance and within-class divergence among the training dataset has been proposed […]

Ultrasound Plaque Enhanced Activity Index for Predicting Neurological Symptoms (Pattern Recognition and Image Analysis)

Abstract This paper aims at developing an ultrasound-based diagnostic measure which quantifies plaque activity, that is, the likelihood of the asymptomatic lesion to produce neurological symptoms. The method is rooted on the identification of an "active" plaque profile containing the most relevant ultrasound parameters associated with symptoms. This information is used to build an Enhanced […]

On the Distribution of Dissimilarity Increments (Pattern Recognition and Image Analysis)

Abstract This paper proposes a statistical model for the dissimilarity changes (increments) between neighboring patterns which follow a 2-dimensional Gaussian distribution. We propose a novel clustering algorithm, using that statistical model, which automatically determines the appropriate number of clusters. We apply the algorithm to both synthetic and real data sets and compare it to a […]

Unsupervised Joint Feature Discretization and Selection (Pattern Recognition and Image Analysis)

Abstract In many applications, we deal with high dimensional datasets with different types of data. For instance, in text classification and information retrieval problems, we have large collections of documents. Each text is usually represented by a bag-of-words or similar representation, with a large number of features (terms). Many of these features may be irrelevant […]

Probabilistic Ranking of Product Features from Customer Reviews (Pattern Recognition and Image Analysis)

Abstract In this paper, we propose a methodology for obtaining a probabilistic ranking of product features from a customer review collection. Our approach mainly relies on an entailment model between opinion and feature words, and suggest that in a probabilistic opinion model of words learned from an opinion corpus, feature words must be the most […]

Vocabulary Selection for Graph of Words Embedding (Pattern Recognition and Image Analysis)

Abstract The Graph of Words Embedding consists in mapping every graph in a given dataset to a feature vector by counting unary and binary relations between node attributes of the graph. It has been shown to perform well for graphs with discrete label alphabets. In this paper we extend the methodology to graphs with n-dimensional […]

Feature Selection in Regression Tasks Using Conditional Mutual Information (Pattern Recognition and Image Analysis)

Abstract This paper presents a supervised feature selection method applied to regression problems. The selection method uses a Dissimilarity matrix originally developed for classification problems, whose applicability is extended here to regression and built using the conditional mutual information between features with respect to a continuous relevant variable that represents the regression function. Applying an […]

Dual Layer Voting Method for Efficient Multi-label Classification (Pattern Recognition and Image Analysis)

Abstract A common approach for solving multi-label classification problems using problem-transformation methods and dichotomizing classifiers is the pairwise decomposition strategy. One of the problems with this approach is the need for querying a quadratic number of binary classifiers for making a prediction that can be quite time consuming, especially in classification problems with large number […]

Passive-Aggressive for On-Line Learning in Statistical Machine Translation (Pattern Recognition and Image Analysis)

Abstract New variations on the application of the passive-aggressive algorithm to statistical machine translation are developed and compared to previously existing approaches. In online adaptation, the system needs to adapt to real-world changing scenarios, where training and tuning only take place when the system is set-up for the first time. Post-edit information, as described by […]

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