Using Ontologies for Semantic Data Integration

While big data analytics is considered as one of the most important paths to competitive advantage of today’s enterprises, data scientists spend a comparatively large amount of time in the data preparation and data integration phase of a big data project. This shows that data integration is still a major challenge in IT applications. Over the past two decades, the idea of using semantics for data integration has become increasingly crucial, and has received much attention in the AI, database, web, and data mining communities. Here, we focus on a specific paradigm for semantic data integration, called Ontology-Based Data Access (OBDA). The goal of this paper is to provide an overview of OBDA, pointing out both the techniques that are at the basis of the paradigm, and the main challenges that remain to be addressed

Generating collaborative systems for digital libraries: A model-driven approach

This is an open access article shared under a Creative Commons Attribution 3.0 Licence (http://creativecommons.org/licenses/by/3.0/). Copyright @ 2010 The Authors.The design and development of a digital library involves different stakeholders, such as: information architects, librarians, and domain experts, who need to agree on a common language to describe, discuss, and negotiate the services the library has to offer. To this end, high-level, language-neutral models have to be devised. Metamodeling techniques favor the definition of domainspecific visual languages through which stakeholders can share their views and directly manipulate representations of the domain entities. This paper describes CRADLE (Cooperative-Relational Approach to Digital Library Environments), a metamodel-based framework and visual language for the definition of notions and services related to the development of digital libraries. A collection of tools allows the automatic generation of several services, defined with the CRADLE visual language, and of the graphical user interfaces providing access to them for the final user. The effectiveness of the approach is illustrated by presenting digital libraries generated with CRADLE, while the CRADLE environment has been evaluated by using the cognitive dimensions framework

NOSTROMO - D1.2 - Final Project Results Report

The main objective of the NOSTROMO project has been to develop, demonstrate and evaluate an innovative modelling approach for the rigorous and comprehensive assessment of the performance impact of future ATM concepts and solutions at ECAC network level. This approach brings together the ability of bottom-up microscopic models to capture emergent behaviour and interdependencies between different solutions with the level of tractability and interpretability required to effectively support decision-making. This report provides a summary of NOSTROMO accomplishments and contributions to the SESAR Programme. It gathers technical lessons learned and concludes proposing further developments to facilitate the use of the NOSTROMO methodology in the future SESAR 3 Programme

Analytical metadata modeling for next generation BI systems

Business Intelligence (BI) systems are extensively used as in-house solutions to support decision-making in organizations. Next generation BI 2.0 systems claim for expanding the use of BI solutions to external data sources and assisting the user in conducting data analysis. In this context, the Analytical Metadata (AM) framework defines the metadata artifacts (e.g., schema and queries) that are exploited for user assistance purposes. As such artifacts are typically handled in ad-hoc and system specific manners, BI 2.0 argues for a flexible solution supporting metadata exploration across different systems. In this paper, we focus on the AM modeling. We propose SM4AM, an RDF-based Semantic Metamodel for AM. On the one hand, we claim for ontological metamodeling as the proper solution, instead of a fixed universal model, due to (meta)data models heterogeneity in BI 2.0. On the other hand, RDF provides means for facilitating defining and sharing flexible metadata representations. Furthermore, we provide a method to instantiate our metamodel. Finally, we present a real-world case study and discuss how SM4AM, specially the schema and query artifacts, can help traversing different models instantiating our metamodel and enabling innovative means to explore external repositories in what we call metamodel-driven (meta)data exploration.Peer ReviewedPostprint (author's final draft

Metamodeling Techniques Applied to the Design of Reconfigurable Control Applications

In order to realize autonomous manufacturing systems in environments characterized by high dynamics and high complexity of task, it is necessary to improve the control system modelling and performance. This requires the use of better and reusable abstractions. In this paper, we explore the metamodel techniques as a foundation to the solution of this problem. The increasing popularity of model-driven approaches and a new generation of tools to support metamodel techniques are changing software engineering landscape, boosting the adoption of new methodologies for control application development

Design, development and characterisation of a Combined Solar Thermal Collection and Radiative Cooling System for heat and cold production

La concepció d'un món millor per a les generacions futures passa pel compromís de mitigar o revertir el canvi climàtic. L'origen del canvi climàtic és ben conegut: l'emissió de gasos d'efecte hivernacle relacionats amb l'ésser humà, bàsicament per la dependència dels combustibles fòssils. És necessari canviar aquest paradigma; és per això que les energies renovables juguen un paper fonamental: ajuden a reduir la dependència energètica dels combustibles fòssils, augmenten la diversificació energètica i són tecnologies de producció d'energia in situ. La present tesi doctoral té com a objectiu contribuir al desenvolupament d'una innovadora tecnologia d'energia renovable per a la producció de calor i fred. La tesi doctoral s’ocupa inicialment de l'estudi i revisió bibliogràfica de la tecnologia anomenada Radiative Cooling, o Refredament Radiatiu, una tecnologia renovable per a la producció de fred mitjançant l'aprofitament del fred disponible a l'espai exterior. Aquesta tecnologia va ser objecte d'investigació en el passat i, gràcies a desenvolupaments recents, està recuperant interès entre les altres tecnologies renovables per a la producció de fred. Els descobriments de l'estudi inicial condueixen la tesi doctoral a enfocar-se en una innovadora combinació de Refredament Radiatiu amb Captació Solar Tèrmica, una tecnologia consolidada, amb fins de rendibilitat i operacionals. Aquesta combinació de tecnologies renovables en un dispositiu físic s’anomenarà Col•lector i Emissor Radiatiu (RCE, sigles en anglès de Radiative Collector and Emitter), basant-se en la importància de la radiació electromagnètica en el balanç de calor en aquesta tecnologia/dispositiu. Després de detectar les condicions climàtiques desitjades per a facilitar l'àmplia implementació de RCE en edificis, la tesi doctoral segueix amb el disseny, desenvolupament i caracterització d'un dispositiu RCE mitjançant modelatge numèric i proves experimentals. Els resultats demostren la capacitat i idoneïtat de RCE per escalfament i refredament, i presenten els paràmetres més influents de les aplicacions RCE.La concepción de un mundo mejor para las generaciones futuras pasa por el compromiso de mitigar o revertir el cambio climático. El origen del cambio climático es bien conocido: la emisión de gases de efecto invernadero relacionados con el ser humano, básicamente por la dependencia de los combustibles fósiles. Es necesario cambiar este paradigma; es por eso que las energías renovables juegan un papel fundamental: ayudan a reducir la dependencia energética de los combustibles fósiles, aumentan la diversificación energética y son tecnologías de producción de energía in situ. La presente tesis doctoral tiene como objetivo contribuir al desarrollo de una innovadora tecnología de energía renovable para la producción de calor y frío. La tesis doctoral se ocupa inicialmente del estudio y revisión bibliográfica de la tecnología llamada Radiative Cooling, o Enfriamiento Radiativo, una tecnología renovable para la producción de frío mediante el aprovechamiento del frío disponible en el espacio exterior. Esta tecnología fue objeto de investigación en el pasado y, gracias a desarrollos recientes, vuelve a ganar interés entre las demás tecnologías renovables para la producción de frío. Los descubrimientos del estudio inicial conducen la tesis doctoral a enfocarse en una innovadora combinación de Enfriamiento Radiativo con Captación Solar Térmica, una tecnología consolidada, con fines de rentabilidad y operacionales. Esta combinación de tecnologías renovables en un dispositivo físico se mencionará Colector y Emisor Radiativo (RCE, siglas en ingles de Radiative Collector and Emitter), basándose en la importancia de la radiación electromagnética en el balance de calor en esta tecnología/dispositivo. Después de detectar las condiciones climáticas deseadas para facilitar la amplia implementación de RCE en edificios, la tesis doctoral sigue con el diseño, desarrollo y caracterización de un dispositivo RCE mediante modelado numérico y pruebas experimentales. Los resultados demuestran la capacidad y la idoneidad de RCE para calentamiento y enfriamiento, y presentan los parámetros más influyentes de las aplicaciones RCE.The conception of a better world for future generations passes through the commitment to mitigate or reverse climate change. The origin of climate change is well-known: the human-related emission of greenhouse gases, basically from fossil fuel burning dependency. There is a need to change this paradigm; therefore, renewable energies play an essential role: they help reduce energy dependency on fossils fuels, increase energy diversification and are on-site energy production technologies. The present PhD thesis aims to contribute to the development of a novel renewable energy technology for heat and cold production. The PhD thesis initially deals with the study and review of Radiative Cooling technology, a renewable technology for cold production by harvesting the coldness of the outer space. This technology was investigated in the past and, thanks to recent developments, it is regaining interest among the renewable technologies for cold production. The findings from the initial study lead the present PhD thesis to focus on a novel combination of Radiative Cooling with Solar Thermal Collection, a well-established technology, for profitability and operational purposes. This combination of renewable technologies in a physical device is onwards named Radiative Collector and Emitter (RCE), based on the importance of electromagnetic radiation in the heat balance in this technology/device. After the spotting of the desired climatic conditions to ease the broadwise implementation of RCE in buildings, the PhD thesis follows to the design, development and characterisation of an RCE device by numerical modelling and experimental testing. The results demonstrate RCE ability and suitability for heating and cooling, and present the most influencing parameters of RCE applications