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Part 7: Decisions; International audience; For the contemporary enterprises, possibility of appropriate business decision making on the basis of the knowledge hidden in stored data is the critical success factor. Therefore, the decision support software should take into consideration that data usually comes continuously in the form of so-called data stream, but most of the traditional data analysis methods are not ready to efficiently analyze fast growing amount of the stored records. Additionally, one should also consider phenomenon appearing in data stream called concept drift, which means that the parameters of an using model are changing, what could dramatically decrease the analytical model quality. This work is focusing on the classification task, which is very popular in many practical cases as fraud detection, network security, or medical diagnosis. We propose how to detect the changes in the data stream using combined concept drift detection model. The experimental evaluations confirm its pretty good quality, what encourage us to use it in practical applications.

This paper describes a novel x-ray fluorescence spectrometer designed for elemental mapping applications. The spectrometer is based on a ring-shaped monolithic array of silicon drift detectors (SDDs) with a hole in the center. The coaxial x-ray excitation beam, focused by a polycapillary x-ray lens, reaches the sample after passing through the central hole. This geometry optimizes the useful solid angle for collecting the fluorescence from the sample, while the optics maximizes the photon density in the excitation spot. These features, together with the very high detection rate of SDDs, allow a high scanning rate in elemental mapping to be achieved. Moreover, the spectroscopic resolution of SDDs (cooled by thermoelectric Peltier elements) is comparable to that of the classical Si(Li) liquid nitrogen-cooled detectors. Several examples of applications of the novel spectrometer in various fields, from archeometry to biology, are presented. This paper introduces also a new multi-element detector based on SDDs whose structure has been specifically optimized for very high resolution and very fast elemental mapping.