Nuclear Tetrahedral Symmetry

We recall the main features of the Td (tetrahedral) symmetry in atomic nuclei and present realistic mean-field calculations supporting the existence such a symmetry all over the nuclear chart. A few potential candidate-nuclei are investigated and the possible experimental signatures of the tetrahedral symmetry are also briefly discussed.Comment: Proceedings of the Xth Marie Curie Nuclear Theory Workshop, Kazimierz Dolny, Poland 4 pages, 1 figur

Collective Rotation of Tetrahedral Nuclei in the Cranking Model

The three-dimensional cranking model is used to investigate the microscopic aspects of the rotation of nuclei with the tetrahedral symmetry. Two classes of rotation axes are studied corresponding to two different discrete symmetries of the rotating hamiltonian. Self-consistent Hartree-Fock-Bogoliubov calculations show that the tetrahedral minimum remains remarkably stable until the first single-particle crossing.Comment: Proceedings of the XII Nuclear Physics Workshop Pierre and Marie Curie, October 2005. To be published in IJMP

DYNAMIC CLASSIFICATION OF GEOGRAPHIC POINTS ON GOOGLE MAPS

Classification of geographical points on Google maps is an interesting example of the use of cluster analysis algorithm in which the final number of clusters is obtained not only by presuppositions and the algorithm used, but also by the scale, on which map is actually displayed. The ultimate goal of classification is not only to obtain relatively homogeneous clusters, but also to prevent the phenomenon of "blurring" partitions on the map. In the paper there is proposed an algorithm that automatically creates a hierarchical structure of classes (which differs, however, from the structures obtained by the hierarchical agglomerative methods), in such way that the final classification takes into account the enlargement in which the map is displayed. The aim of article is illustrated with real examples on Google maps using JavaScript / JQuery