On-line analytical processing (OLAP) is a recent and important application of database systems. Typically, OLAP data is presented as a multidimensional \data cube." OLAP queries are complex and can take many hours or even days to run, if executed directly on the raw data. The most common method of reducing execution time is to precompute some of the queries into summary tables (subcubes of the ...

Laser diffraction is one of the most widely used methods for particle size analysis of micron and submicron size powders and dispersions. It is quick and easy and provides very consistent, repeatable information. Since these instruments use scattered light intensity to determine particle size, knowledge of the optical properties, specifically the complex refractive index of the material being a...

This paper aims at introducing the concept of selection graph with an application to a non-trivial problem. A selection graph is made of a set of classes, each class having multiple realizations, and of an uncompatibility graph built on these realizations. Coloring a selection graph can be used to solve constrained scheduling, constrained ressource allocation, and dichotomy-based constrained en...

Spectral data often have a large number of highly-correlated features, making feature selection both necessary and uneasy. A methodology combining hierarchical constrained clustering of spectral variables and selection of clusters by mutual information is proposed. The clustering allows reducing the number of features to be selected by grouping similar and consecutive spectral variables togethe...

We study causal subset selection with Directed Information as the measure of prediction causality. Two typical tasks, causal sensor placement and covariate selection, are correspondingly formulated into cardinality constrained directed information maximizations. To attack the NP-hard problems, we show that the first problem is submodular while not necessarily monotonic. And the second one is “n...