Certified Rapid Solution of Parametrized Linear Elliptic Equations: Application to Parameter Estimation

We present a technique for the rapid and reliable evaluation of linear-functional output of elliptic partial differential equations with affine parameter dependence. The essential components are (i) rapidly uniformly convergent reduced-basis approximations — Galerkin projection onto a space WN spanned by solutions of the governing partial differential equation at N (optimally) selected points in parameter space; (ii) a posteriori error estimation — relaxations of the residual equation that provide inexpensive yet sharp and rigorous bounds for the error in the outputs; and (iii) offline/online computational procedures — stratagems that exploit affine parameter dependence to de-couple the generation and projection stages of the approximation process. The operation count for the online stage — in which, given a new parameter value, we calculate the output and associated error bound — depends only on N (typically small) and the parametric complexity of the problem. The method is thus ideally suited to the many-query and real-time contexts. In this paper, based on the technique we develop a robust inverse computational method for very fast solution of inverse problems characterized by parametrized partial differential equations. The essential ideas are in three-fold: first, we apply the technique to the forward problem for the rapid certified evaluation of PDE input-output relations and associated rigorous error bounds; second, we incorporate the reduced-basis approximation and error bounds into the inverse problem formulation; and third, rather than regularize the goodness-of-fit objective, we may instead identify all (or almost all, in the probabilistic sense) system configurations consistent with the available experimental data — well-posedness is reflected in a bounded "possibility region" that furthermore shrinks as the experimental error is decreased.

Managing A Changing Relationship: China's Japan Policy in the 1990s

This paper was prepared for the conference on "China into the twenty-first century: Strategic partner and...or peer competitor"

Meaning of the λ parameter of skew–normal and log–skew normal distributions in fluid geochemistry

The literature related to skew–normal distributions has grown rapidly in recent years but at the moment few applications concern the description of natural phenomena with this type of probability models, as well as the interpretation of their parameters. The skew–normal distributions family represents an extension of the normal family to which a parameter (λ) has been added to regulate the skewness. The development of this theoretical field has followed the general tendency in Statistics towards more flexible methods to represent features of the data, as adequately as possible, and to reduce unrealistic assumptions as the normality that underlies most methods of univariate and multivariate analysis. In this paper an investigation on the shape of the frequency distribution of the logratio ln(Cl−/Na+) whose components are related to waters composition for 26 wells, has been performed. Samples have been collected around the active center of Vulcano island (Aeolian archipelago, southern Italy) from 1977 up to now at time intervals of about six months. Data of the logratio have been tentatively modeled by evaluating the performance of the skew–normal model for each well. Values of the λ parameter have been compared by considering temperature and spatial position of the sampling points. Preliminary results indicate that changes in λ values can be related to the nature of environmental processes affecting the data

Towards economic and monetary union: changing trends in payment systems for new european members

The objective of this paper is precisely to study the evolution of payment systems within the accession countries between 1996 and 2003 and compare them with those of the E.U. and the Eurozone countries

Earth's Changing Land

Entre el 14 i el 18 de març de 1998 es va celebrar a Barcelona la conferència Earth’s Changing Land sota la tutela dels programes internacionals Global Change in Terrestrial Ecosystems (GCTE) i Land Use and Land Cover Change (LUCC). L’objectiu principal de la trobada era presentar les darreres aportacions científiques sobre els efectes presents i previsibles del canvi global sobre els ecosistemes terrestres i la societat. Al mateix temps, es volia afavorir l’establiment de ponts de diàleg entre els professionals implicats en el canvi global

Fault diagnosis by refining the parameter uncertainty space of nonlinear dynamic systems

This paper deals with fault detection and isolation problems for nonlinear dynamic systems. Both problems are stated as constraint satisfaction problems (CSP) and solved using consistency techniques. The main contribution is the isolation method based on consistency techniques and uncertainty space refining of interval parameters. The major advantage of this method is that the isolation speed is fast even taking into account uncertainty in parameters, measurements, and model errors. Interval calculations bring independence from the assumption of monotony considered by several approaches for fault isolation which are based on observers. An application to a well known alcoholic fermentation process model is presented

Changing text and background colours in Adobe Acrobat

A 4-minute video that shows how students with dyslexia or visual stress can change the text and background colours in Adobe Acrobat Reader to suit their needs.

Changing Education Paradigms - Sir Ken Robinson

This animation was adapted from a talk given at the RSA by Sir Ken Robinson, world-renowned education and creativity expert and recipient of the RSA's Benjamin Franklin award. For more information on Sir Ken's work visit: http://www.sirkenrobinson.com

UbiCamp How the web is changing the world

OER for UbiCamp Project - resource collection

Changing dynamics of the interinstitutional relationships between executive and legislature power in Colombia (2002/2006)

This paper describes the relationship between the executive and legislative branches during the first government of Alvaro Uribe Vélez. We will focus on reviewing the legislative output of each branch of power, along with the effectiveness and efficiency they showed as promoters of this production. We will review the impact they had on the legislative agenda setting and on the control of the legislative process  itself, making a diachronic analysis in which each legislature is used as a unit. Thus, we will try to identify the presence (or not) of some kind of pattern interactions,  and we will evaluate, at one hand, the existence of hierarchical and transactional trends, and, on the other, the different types of balances produced  between them.

Earth's changing rives.

Analiza la geografía de los ríos así como la manera en que los asentamientos humanos en las regiones fluviales de todo el mundo han cambiado el paisaje. Un examen a través de estudios de casos, mapas, fotografías aéreas, ilustra los efectos que han tenido los seres humanos en estos terrenos y sobre el medio ambiente circundante. Tiene glosario y bibliografía.

Earth's changing continents.

Permite ver cómo se han ido formando los continentes a los largo de millones de años. Explica cómo se forma el paisaje así como el modo en que las personas y los asentamientos humanos lo cambian. Por último se examina cómo los cambios en el medio ambiente están afectando a los paisajes del mundo e incluye la discusión de por qué el clima puede cambiar en el futuro. El estudio de casos se utiliza para abrir la posibilidad de comparar y contrastar lo aprendido.

Earth's changing islands.

Permite ver cómo se han ido formando las islas a los largo de millones de años. Un examen a través de estudios de casos, mapas y fotografías aéreas, ilustra los efectos que los seres humanos han tenido en estos accidentes geográficos y cómo cambian. Por último se aportan datos sobre las islas más grande del mundo, las islas más densamente pobladas y las que tienen las montañas más altas. iene un glosario de apoyo lingüístico y bibliografía.

Eart's changing deserts.

Permite ver cómo se han ido formando los desiertos a los largo de millones de años. Un examen a través de estudios de casos, mapas y fotografías aéreas, ilustra los efectos de estos paisajes cambiantes contestando , entre otras, a las preguntas de cómo sobrevive la gente en los desiertos. Si cada vez hay en el mundo más zonas desérticas y cómo los animales y las plantas se han adaptado a vivir en ellas. Por último se aportan datos sobre los desiertos más grande del mundo y su densidad de población. iene un glosario de apoyo lingüístico y bibliografía.