Interrelation Of Features Research Articles

Effective construction of classifiers with the k-NN method supported by a concept ontology

In analysing sensor data, it usually proves beneficial to use domain knowledge in the classification process in order to narrow down the search space of relevant features. However, it is often not effective when decision trees or the k-NN method is used. Therefore, the authors herein propose to build an appropriate concept ontology based on expert knowledge. The use of an ontology-based metric enables mutual similarity to be determined between objects covered by respective concept ontology, taking into consideration interrelations of features at various levels of abstraction. Using a set of medical data collected with the Holter method, it is shown that predicting coronary disease with the use of the approach proposed is much more accurate than in the case of not only the k-NN method using classical metrics, but also most other known classifiers. It is also proved in this paper that the expert determination of appropriate structure of ontology is of key importance, while subsequent selection of appropriate weights can be automated.

Changes in Infants' Cries as a Function of Time in a Cry Bout

The present study examines changes in cry sounds over the course of a relatively long bout of crying. Specifically, differences in acoustic characteristics of 5 cries from early and 5 cries from late in a prolonged cry bout were assessed. The results indicated that several features changed in means and/or variances between early and late in the bout. A subset of 9 acoustic features was chosen to evaluate changes in the interrelations of features over time. Cries from late in the bout appeared to result from a smaller number of factors, which were more readily interpretable in terms of a standard model of cry production. Thus, it appears that as infants' level of arousal or distress changes, so do the acoustic features of their cries. Further, the results support the notion that bouts of crying settle into a "basic" or regular cry whose acoustic features provide a reasonable match with a theoretical model of cry production.