478 research outputs found
Spatial cross-correlation of Antarctic Sea ice and seabed topography
A time series of derived sea ice concentrations as observed about Antarctica by the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) satellite in 1983 is considered. The degree of spatial cross correlation between these data and seabed topography is quantified. The approach is to implement a statistical image processing filter designed to extract local patterns of spatial cross correlation over the entire sea ice field as it undergoes daily changes. Throughout the sea ice, it was found that large scale variations in sea ice concentration correlate systematically with variations in the topography of the seabed. Generally speaking, high concentrations of sea ice occur over deep ocean, whereas areas of encavement, early dissipation and polynya formation develop over topographic features of high elevation. The latter was studied in detail with respect to the features Maud Rise, Astrid Ridge and the continental shelf in the Cosmonaut and Ross Seas. In each case, it is shown that an encavement in sea ice, a polynya, or both develops in the vicinity of the feature in question. As these results are quantified in terms of spatial cross correlation, a potential role is inferred for seabed topography in such fluctuations in the sea ice about Antarctica
Spécification d'un interpréteur de mini-langage algotithmique pour l'initiaition à la programmation
L'emploi des outils habituels de développement (éditeurs, compilateurs, etc.) dans l'initiation à l'algorithmique conduit à de nombreuses difficultés pratiques, parfois insurmontables par les étudiants. En réponse à ce problème, cet article présente les spécifications et les premiers éléments d'analyse d'un logiciel "d'aide à l'apprentissage de l'algorithmique" qui est en cours de réalisation à l'I.U.T. de Vannes.Conçu dans un objectif de formation professionnelle, ce logiciel didactique doit servir de prototype pour l'étude et la réalisation ultérieures d'outils modulaires d'aide au développement dans un contexte de recherche de Qualité Industrielle
Non-ionizing radiation hardness of CMOS Monolithic Active Pixel Sensors manufactured in a 0.18m CMOS process
- …