Most developed countries exhibit high rates of R&D performed in industry, but the situation is considerable different in medium income countries such as Portugal. Despite the lower levels of R&D, Portuguese firms have increased their competitiveness, and the country has been able to show remarkable levels of economic performance. This paper provides a framework to analyze the way in which R&D i...

Mining local structure is important in data analysis. Gaussian mixture is able to describe local structure through the covariance matrices, but when used on highdimensional data, fitly specifying such a large number of d(d + 1)=2 free elements in each covariance matrix is difficult. In this paper, by constraining the covariance matrix in decomposed orthonormal form, we propose a Local PCA algor...

Article history: Received 5 April 2015 Received in revised form 30 May 2015 Accepted 2 June 2015 Available online 9 June 2015 Communicated by D.-Z. Du

Competition, despite its potential drawbacks, is an easily adopted and frequently used motivator in classrooms. Individual abilities, in the years of schooling, are inevitably different, and performance in competition is heavily ability dependent, resulting that more-able students always win while less-able students always lose. Students easily perceive how well they perform through the result ...

We prove a lower bound ρ ≥ 9.001 for the competitive ratio of the so-called online matching problem on a line. As a consequence, the online matching problem is revealed to be strictly more difficult than the “cow problem”.

This paper modified the mechanism of weight adjusting of the Self-Organizing Mapping network (SOM) for solving the problems of topology preserving and clarifying boundary of clustering graph for the clustering analysis. The modified SOM is named the Multiple Clustering Centers SOM (MCC-SOM). The MCC-SOM changed the competitive learning mechanism of “winner takes all” to allow the more one clust...

A significant challenge that faces any teacher of introductory programming is the diversity of the class. At one extreme there will be students who have never programmed before, while at the other there will be students who have many years experience of programming. Handling this diversity is difficult. The temptation for the instructor is often to focus on the novice group and to assume that t...