Tuesday 13 August 2013

Ernest Everett

The Life of Ernest Everett Just is an autobiography of African-American biologist Ernest Everett Just, written in 1983 by Kenneth R. Manning. The book was named one of 1984's "notable books" by The New York Times. Ernest Everett Just was a revolutionary African – American biologist, academic and science writer. 

Just primary inheritance is his recognition of the fundamental role of the cell surface in the growth of organisms. In his work within cytology, marine biology and parthenogenesis, he suggested the study of whole cells under normal conditions, rather than simply breaking them apart in a laboratory setting. Besides, Just also left an undying impression within the African American community for his skill to pursue a high level of education despite the racial obstacles that he faced.

Monday 4 March 2013

Adaptive Information Filtering: Learning Drifting Concepts

The task of information filtering is to classify texts from a stream of documents into relevant and non relevant, respectively, with respect to a particular category or user interest, which may change over time. A filtering system should be able to adapt to such concept changes. This paper explores methods to recognize concept changes and to maintain windows on the training data, whose size is either fixed or automatically adapted to the current extent of concept change. Experiments with two simulated concept drift scenarios based on real-world text data and eight learning methods are performed to evaluate three indicators for concept changes and to compare approaches with fixed and adjustable window sizes, respectively, to each other and to learning on all previously seen examples. Even using only a simple window on the data already improves the performance of the classifiers significantly as compared to learning on all examples. For most of the classifiers, the window adjustments lead to a further increase in performance compared to windows of fixed size. The chosen indicators allow to reliably recognize concept changes.