University of Alicante

About: University of Alicante is a education organization based out in Alicante, Spain. It is known for research contribution in the topics: Catalysis & Population. The organization has 8681 authors who have published 22690 publications receiving 476064 citations. The organization is also known as: Universitat d'Alacant & Universidad de Alicante.

Question Answering in Restricted Domains: An Overview

Abstract: Automated question answering has been a topic of research and development since the earliest AI applications. Computing power has increased since the first such systems were developed, and the general methodology has changed from the use of hand-encoded knowledge bases about simple domains to the use of text collections as the main knowledge source over more complex domains. Still, many research issues remain. The focus of this article is on the use of restricted domains for automated question answering. The article contains a historical perspective on question answering over restricted domains and an overview of the current methods and applications used in restricted domains. A main characteristic of question answering in restricted domains is the integration of domain-specific information that is either developed for question answering or that has been developed for other purposes. We explore the main methods developed to leverage this domain-specific information.

Mechanistic studies of the 'blue' Cu enzyme, bilirubin oxidase, as a highly efficient electrocatalyst for the oxygen reduction reaction

Abstract: The ‘blue copper’ enzyme bilirubin oxidase from Myrothecium verrucaria shows significantly enhanced adsorption on a pyrolytic graphite ‘edge’ (PGE) electrode that has been covalently modified with naphthyl-2-carboxylate functionalities by diazonium coupling. Modified electrodes coated with bilirubin oxidase show electrocatalytic voltammograms for the direct, four-electron reduction of O2 by bilirubin oxidase with up to four times the current density of an unmodified PGE electrode. Electrocatalytic voltammograms measured with a rapidly rotating electrode (to remove effects of O2 diffusion limitation) have a complex shape (an almost linear dependence of current on potential below pH 6) that is similar regardless of how PGE is chemically modified. Importantly, the same waveform is observed if bilirubin oxidase is adsorbed on Au(111) or Pt(111) single-crystal electrodes (at which activity is short-lived). The electrocatalytic behavior of bilirubin oxidase, including its enhanced response on chemically-modified PGE, therefore reflects inherent properties that do not depend on the electrode material. The variation of voltammetric waveshapes and potential-dependent (O2) Michaelis constants with pH and analysis in terms of the dispersion model are consistent with a change in rate-determining step over the pH range 5–8: at pH 5, the high activity is limited by the rate of interfacial redox cycling of the Type 1 copper whereas at pH 8 activity is much lower and a sigmoidal shape is approached, showing that interfacial electron transfer is no longer a limiting factor. The electrocatalytic activity of bilirubin oxidase on Pt(111) appears as a prominent pre-wave to electrocatalysis by Pt surface atoms, thus substantiating in a single, direct experiment that the minimum overpotential required for O2 reduction by the enzyme is substantially smaller than required at Pt. At pH 8, the onset of O2 reduction lies within 0.14 V of the four-electron O2/2H2O potential.

An MDA approach for the development of data warehouses.

Abstract: Different modeling approaches have been proposed to overcome every design pitfall of different data warehouse (DW) components. However, most of them offer partial solutions that deal only with isolated aspects of the DW and do not provide developers with an integrated and standard framework for designing all DW relevant components, such as ETL processes, data sources, DW repository and so on. To overcome this problem, this paper describes how to align the whole DW development process with a Model Driven Architecture (MDA) framework. We then focus on describing one part of it: an MDA approach for the development of the DW repository, because it is the cornerstone of any DW system. Therefore, we describe how to build the different MDA models for the DW repository by using an extension of the Unified Modeling Language (UML) and the Common Warehouse Metamodel (CWM). Transformations between models are also clearly and formally established by using the Query/View/Transformation (QVT) language. Finally, a case study is provided to exemplify the benefits of our MDA framework.