BACKGROUND Diffusion-weighted imaging (DWI) is a form of magnetic resonance imaging (MRI) based on measuring the random Brownian motion of water molecules within the biological tissues and is particularly useful in tumor characterization. OBJECTIVES The purpose of this study was to evaluate the diagnostic value of DW MRI and the apparent diffusion coefficient (ADC) for preoperative grading of...

In fuzzy data analysis, a simple correlation coefficient provides us with a good sense of linear relationship between two fuzzy attributes, while a partial correlation coefficient shows the relationship between two fuzzy attributes when the influences of other fuzzy attributes are partialed out from both of the two attributes. But, in some practical applications, we need to use the correlation ...

Given n vectors x0, x1, . . . , xn−1 in {0, 1}m, how to find two vectors whose pairwise Hamming distance is minimum? This problem is known as the Closest Pair Problem. If these vectors are generated uniformly at random except two of them are correlated with Pearson-correlation coefficient ρ, then the problem is called the Light Bulb Problem. In this work, we propose a novel coding-based scheme ...

The Minimum Redundancy Maximum Relevance (MRMR) approach to supervised variable selection represents a successful methodology for dimensionality reduction, which is suitable for high-dimensional data observed in two or more different groups. Various available versions of the MRMR approach have been designed to search for variables with the largest relevance for a classification task while contr...

OBJECTIVE To evaluate the reliability and validity of the Brazilian version of the Pittsburgh Sleep Quality Index. METHODS 309 adolescents, subdivided into a sample of 209 subjects, of whom 25 were reassessed, and another sample of 100 adolescents. Reliability was assessed using Cronbach's α-values, intraclass correlation coefficient, Standard Error of Measure, Minimum Detectable Change, and ...

The method used for pulse transit time (PTT) estimation critically affects the accuracy and precision of regional pulse wave velocity (PWV) measurements. Several methods of PTT estimation exist, often yielding substantially different PWV values. Since there is no analytic way to determine PTT in vivo, these methods cannot be validated except by using in silico or in vitro models of known PWV an...

Neher et al 2 Summary Typically, measurements that aim to predict perceived spatial impression of music signals in concert halls are performed by calculating the interaural cross-correlation coefficient (IACC) of a binaurally-recorded impulse response. Previous research, however, has shown that this can lead to results very different from those obtained if a musical input signal is used. The re...

The search for multivariate linear regression (MLR) in quantitative structure-property relationships (QSPR) is a hard problem, due to the dimension of the entire search space. A genetic algorithm (GA) was developed and assessed, to select proper descriptors for predicting the octan-1-ol/H2O partition coefficient of polychlorinated biphenyls. The GA was implemented as a Windows based FreePascal ...