Discarge compilation from The Global River Discharge (RivDIS) Project

The Global River Discharge (RivDIS) data set contains monthly discharge measurements for 1018 stations located throughout the world. The period of record varies widely from station to station, with a mean of 21.5 years. These data were digitized from published UNESCO archives by Charles Voromarty, Balaze Fekete, and B.A. Tucker of the Complex Systems Research Center (CSRC) at the University of New Hampshire. River discharge is typically measured through the use of a rating curve that relates local water level height to discharge. This rating curve is used to estimate discharge from the observed water level. The rating curves are periodically rechecked and recalibrated through on-site measurement of discharge and river stage.

solaR: geometría, radiación y energía solar en R

The solaR package includes a set of functions to calculate the solar radiation incident on a photovoltaic generator and simulate the performance of several applications of the photovoltaic energy. This package performs the whole calculation procedure from both daily and intradaily global horizontal irradiation to the final productivity of grid connected PV systems and water pumping PV systems. The package stands on a set of S4 classes. The core of each class is a group of slots with yearly, monthly, daily and intradaily multivariate time series (with the zoo package ). The classes share a variety of methods to access the information (for example, as.zooD provides a zoo object with the daily multivariate time series of the corresponding object) and several visualisation methods based on the lattice andlatticeExtra packages.

Prólogo de La construcción de las bóvedas en le Edad Media por R. Willis

Robert Willis publica en 1842 un artículo extraordinario sobre la Construcción de las bóvedas en la Edad Media. Hasta entonces, los anticuarios habían imaginado la geometría de las bóvedas en base a mediciones muy generales y al aspecto global. No era fácil medir una bóveda con precisión pues se necesitaban andamios. Sólo en las bóvedas más pequeñas, quizá se pudieron tomar algunas medidas con ayuda de una escalera. Pero hallar la curvatura de los nervios era una tarea dificil que, por otro lado, no parecía preocupar mucho a estos viajeros que visitaron centenares de edificios. Fue Willis el primero en afrontar el problema de forma directa. Su trabajo tenía un objetivo concreto: descubrir los métodos y reglas empleados por los constructores medievales a la hora de proyectar la forma general de las bóvedas (definida por los nervios), así como el corte de las piedras en los puntos más difíciles (el arranque, las claves). Por otra parte, no se trataba de un interés meramente arqueológico. Conocidas las reglas los arquitectos, señala Willis, podrían imitar (con conocimiento y criterio) y no simplemente copiar los edificios medievales.

A practical approach to the global analysis of CLP programs

This paper presents and illustrates with an example a practical approach to the dataflow analysis of programs written in constraint logic programming (CLP) languages using abstract interpretation. It is first argued that, from the framework point of view, it sufnces to propose relatively simple extensions of traditional analysis methods which have already been proved useful and practical and for which efncient fixpoint algorithms have been developed. This is shown by proposing a simple but quite general extensión of Bruynooghe's traditional framework to the analysis of CLP programs. In this extensión constraints are viewed not as "suspended goals" but rather as new information in the store, following the traditional view of CLP. Using this approach, and as an example of its use, a complete, constraint system independent, abstract analysis is presented for approximating definiteness information. The analysis is in fact of quite general applicability. It has been implemented and used in the analysis of CLP(R) and Prolog-III applications. Results from the implementation of this analysis are also presented.