Multidimensional scaling visualization of earthquake phenomena

Earthquakes are associated with negative events, such as large number of casualties, destruction of buildings and infrastructures, or emergence of tsunamis. In this paper, we apply the Multidimensional Scaling (MDS) analysis to earthquake data. MDS is a set of techniques that produce spatial or geometric representations of complex objects, such that, objects perceived to be similar/distinct in some sense are placed nearby/distant on the MDS maps. The interpretation of the charts is based on the resulting clusters since MDS produces a different locus for each similarity measure. In this study, over three million seismic occurrences, covering the period from January 1, 1904 up to March 14, 2012 are analyzed. The events, characterized by their magnitude and spatiotemporal distributions, are divided into groups, either according to the Flinn–Engdahl seismic regions of Earth or using a rectangular grid based in latitude and longitude coordinates. Space-time and Space-frequency correlation indices are proposed to quantify the similarities among events. MDS has the advantage of avoiding sensitivity to the non-uniform spatial distribution of seismic data, resulting from poorly instrumented areas, and is well suited for accessing dynamics of complex systems. MDS maps are proven as an intuitive and useful visual representation of the complex relationships that are present among seismic events, which may not be perceived on traditional geographic maps. Therefore, MDS constitutes a valid alternative to classic visualization tools, for understanding the global behavior of earthquakes.

O terrível nascimento da beleza: a criação literária em diversos autores

De onde brota a inspiração para baladas de amor e canções de guerra, lendas e narrativas, tragédias e comédias? Ao longo de séculos, escritores e leitores interrogaram-se acerca do nascimento da beleza. Neste artigo, abordo essa questão intrigante, em quatro etapas: a) Examino algumas personificações criadas por Hesíodo, Homero, Luís de Camões e Federico García Lorca para descreverem a inspiração; b) Exploro as estratégias utilizadas por Samuel Coleridge, Salvador Dalí e William Burroughs, para penetrar no reino da fantasia, o inconsciente; c) Apresento as explicações científicas propostas por Sigmund Freud, Carl Jung e Robert Sperry para o impulso criativo; d) Para concluir, menciono as razões que levaram Fernando Pessoa, Eugénio de Andrade e Emily Dickinson a desconfiarem da musa inspiradora, preferindo o esforço que corrige a emoção e gera a obra de arte. Seguindo uma perspectiva comparada, o meu objectivo é mostrar diferentes formas de perceber a criatividade literária. Para tanto, recorro ao trabalho dos escritores e cientistas atrás mencionados e, naturalmente, à minha opinião.