In this paper we present a very simple derivation of the constants of motion for dynamical systems, which requires only an elementary knowledge of the theory of continuous groups. In addition, through the infinitesimal Lorenz transformations group, we obtain a…

A two-dimensional Laplace equation is separable in elliptic coordinates and leads to a Chebyshev-like differential equation for both angular and radial variables. In the case of the angular variable η (-1 < η < 1), the solutions are the well…

The book is about diagnostic ultrasound imaging authored by Dr. Thomas L. Zabo. Graduate students in medical physics and biomedical engineering with backgrounds in calculus, complex numbers and some knowledge on electric circuits would benefit from this book.

This paper discusses the concept of cleaner production and proposes a new model to stimulate cleaner production, in the first section the historical development of cleaner production is sketched. It is indicated that the approach gained much attention in the…

J. de Landtsheer, J. Lipsius, Iusti Lipsi epistolae, VIII, 1595'Inner peace and wisdom under a light veil of modesty: Justus Lipsius (1547-1606) and the edition of his correspondence'Humanists wrote and collected private letters, regarding them as literary works of art,…

‘Are you not in prison yet?’ or: how much of a minefield is commissioned research?Historical knowledge can be used for multiple purposes. Consequently, it is hard to make a distinction between studies that criticize government policies and those that support…

OBJECTIVE: To identify individual risk factors for malaria infection of inhabitants in the residual transmission focus on the Pacific coast of Oaxaca, Mexico. MATERIALS AND METHODS: A population-based, matched case-control study was conducted from January 2002 to July 2003 comparing…

Este artigo descreve o processo de desenvolvimento e avalia&ccedil;&atilde;o de um interface com o utilizador para um sistema de escalonamento. Pretende-se disponibilizar ao utilizador, al&eacute;m de uma forma gr&aacute;fica e interativa de definir problemas de escalonamento, uma forma interativa de…

Automatic keyword extraction is an important subfield of information extraction process. It is a difficult task, where numerous different techniques and resources have been proposed. In this paper, we propose a generic approach to extract keyword from documents using encyclopedic…

Here, we address the task of assigning relevant terms to thematically and semantically related sub-corpora and achieve superior results compared to the baseline performance. Our results suggest that more reliable sets of keyphrases can be assigned to the semantically and…