Calculating an exceptional machine

In previous work we showed how to verify a compiler for a small language with exceptions. In this article we show how to calculate, as opposed to verify, an abstract machine for this language. The key step is the use of Reynold's defunctionalization, an old program transformation technique that has recently been rejuvenated by the work of Danvy et al

Le manuscrit « De Progressione Dyadica » de Leibniz

Ce manuscrit exceptionnel, écrit par Leibniz à 33 ans mais non publié, fait le lien entre deux de ses travaux majeurs, paraissant a priori indépendants : son idée du calcul binaire (article de 1703 qui n’évoque pas de machine à calculer) et son idée de machine à calculer décimale (texte BibNum, article de 1710 correspondant au travail de Leibniz de 1673 à 1709). Ces deux idées n’ont sans doute pas été développées indépendamment et, même si Leibniz ne l’a pas publié, ce manuscrit apparaît à ce jour comme la plus ancienne évocation d'un calculateur binaire.Written when Leibniz was 33 years old, this exceptional but unpublished manuscript draws a connection between two of Leibniz’s major areas of research, which previously appeared unrelated: his idea of binary calculation (outlined in an article of 1703, which does not mention a calculating machine) and his idea of a decimal calculating machine (outlined in an article of 1710 that covers Leibniz’s work between 1673 and 1709; this article is a BibNum text). These two ideas were doubtless not developed independently, and although Leibniz did not publish it, this manuscript appears, at present, to be the earliest known description of a binary calculator

Supporting Data mining of large databases by visual feedback queries

In this paper, we describe a query system that provides visual relevance feedback in querying large databases. Our goal is to support the process of data mining by representing as many data items as possible on the display. By arranging and coloring the data items as pixels according to their relevance for the query, the user gets a visual impression of the resulting data set. Using an interactive query interface, the user may change the query dynamically and receives immediate feedback by the visual representation of the resulting data set. Furthermore, by using multiple windows for different parts of a complex query, the user gets visual feedback for each part of the query and, therefore, may easier understand the overall result. Our system allows to represent the largest amount of data that can be visualized on current display technology, provides valuable feedback in querying the database, and allows the user to find results which, otherwise, would remain hidden in the database