This paper addresses an effective learning method that enables us to directly optimize neural network classifier's discrimination performance at a desired local operating range by maximizing a partial area under a receiver operating characteristic (ROC) or domain-specific curve, which is difficult to achieve with classification accuracy or mean squared error (MSE)-based learning methods. The ef...

Receiver operating characteristic (ROC) analysis is now a standard tool for the comparison of binary classifiers and the selection operating parameters when the costs of misclassification are unknown. This chapter outlines the use of evolutionary multi-objective optimisation techniques for ROC analysis, in both its traditional binary classification setting, and in the novel multi-class ROC situ...

ROC Curves (Receiver Operating Characteristic) are remarkably useful in medical decision-making. Given a common measurable characteristic, with a continuous output in all the beings of a group, ROC curves determine a threshold on the values of the characteristic, which tries to predict the classification of beings into discrete classes. In the Facultad de Informática of Valencia (Spain), we hav...

The area under an ROC curve (AUC) has been advocated as an evaluation criterion for bipartite ranking problems. In this paper, we study large deviation properties of the AUC; in particular, we derive a distribution-free large deviation bound for the AUC which serves to bound the expected accuracy of a ranking function in terms of its empirical AUC on an independent test sequence.1 A comparison ...

The aim of this study was to develop and validate under laboratory conditions an algorithm for a time-frequency analysis of rhythmic masticatory muscle activity (RMMA). The algorithm baseband demodulated the electromyographic (EMG) signal to provide a frequency versus time representation. Using appropriate thresholds for frequency and power parameters, it was possible to automatically assess th...

OBJECTIVE To investigate the significance of intra-appendiceal air at CT for the evaluation of appendicitis. MATERIALS AND METHODS We retrospectively analyzed 458 patients (216 men, 242 women; age range, 18-91 years) who underwent CT for suspected appendicitis. Two independent readers reviewed the CT. Prevalence, amount, and appearance of intra-appendiceal air were assessed and compared betwe...

OBJECTIVE To develop an additive numerical scoring scheme for the Classic BILAG index. METHODS SLE patients were recruited into this multi-centre cross-sectional study. At every assessment, data were collected on disease activity and therapy. Logistic regression was used to model an increase in therapy, as an indicator of active disease, by the Classic BILAG score in eight systems. As both in...

We investigate the suitability of the two existing risk stratification systems available for predicting mortality in a cohort of patients undergoing lung resection under a single surgeon. Data from the 290 consecutive patients who underwent pulmonary resection between January 2008 and January 2011 were extracted from a prospective clinical data base. In-hospital mortality risk scores are calcul...

Consider the ROC surface which is a generalization of the ROC curve for three−class diagnostic problems. In this work, we propose five criteria for the three−class ROC surface by extending the Youden index, the sum of sensitivity and specificity, the maximum vertical distance, the amended closest-to-(0,1) and the true rate. It may be concluded that these five criteria can be expressed as a func...

OBJECTIVE To evaluate the interobserver variability and performance in the interpretation of ultrasonographic (US) findings of thyroid nodules. MATERIALS AND METHODS 72 malignant nodules and 61 benign nodules were enrolled as part of this study. Five faculty radiologists and four residents independently performed a retrospective analysis of the US images. The observers received one training s...