Interactive Data Exploration of Distributed Raw Files: A Systematic Mapping Study

When exploring big amounts of data without a clear target, providing an interactive experience becomes really dif cult, since this tentative inspection usually defeats any early decision on data structures or indexing strategies. This is also true in the physics domain, speci cally in high-energy physics, where the huge volume of data generated by the detectors are normally explored via C++ code using batch processing, which introduces a considerable latency. An interactive tool, when integrated into the existing data management systems, can add a great value to the usability of these platforms. Here, we intend to review the current state-of-the-art of interactive data exploration, aiming at satisfying three requirements: access to raw data les, stored in a distributed environment, and with a reasonably low latency. This paper follows the guidelines for systematic mapping studies, which is well suited for gathering and classifying available studies.We summarize the results after classifying the 242 papers that passed our inclusion criteria. While there are many proposed solutions that tackle the problem in different manners, there is little evidence available about their implementation in practice. Almost all of the solutions found by this paper cover a subset of our requirements, with only one partially satisfying the three. The solutions for data exploration abound. It is an active research area and, considering the continuous growth of data volume and variety, is only to become harder. There is a niche for research on a solution that covers our requirements, and the required building blocks are there

Semantic Web and the Web of Things: concept, platform and applications

The ubiquitous presence of devices with computational resources and connectivity is fostering the diffusion of the Internet of Things (IoT), where smart objects interoperate and react to the available information providing services to the users. The pervasiveness of the IoT across many different areas proves the worldwide interest of researchers from academic and enterprises worlds. This Research has brought to new technologies and protocols addressing different needs of emerging scenarios, making difficult to develop interoperable applications. The Web of Things is born to address this problem through the standard protocols responsible for the success of the Web. But a greater contribution can be provided by standards of the Semantic Web. Semantic Web protocols grant univocal identification of resources and representation of data in a way that information is machine understandable and computable and such that information from different sources can be easily aggregated. Semantic Web technologies are then interoperability enablers for the IoT. This Thesis investigates how to employ Semantic Web protocols in the IoT, to realize the Semantic Web of Things (SWoT) vision of an interoperable network of applications. Part I introduces the IoT, Part II investigates the algorithms to efficiently support the publish/subscribe paradigm in semantic brokers for the SWoT and their implementation in Smart-M3 and SEPA. The preliminary work toward the first benchmark for SWoT applications is presented. Part IV describes the Research activity aimed at applying the developed semantic infrastructures in real life scenarios (electro-mobility, home automation, semantic audio and Internet of Musical Things). Part V presents the conclusions. A lack of effective ways to explore and debug Semantic Web datasets emerged during these activities. Part III describes a second Research aimed at devising of a novel way to visualize semantic datasets, based on graphs and the new concept of Semantic Planes.La presenza massiva di dispositivi dotati di capacità computazionale e connettività sta alimentando la diffusione di un nuovo paradigma nell'ICT, conosciuto come Internet of Things. L'IoT è caratterizzato dai cosiddetti smart object che interagiscono, cooperano e reagiscono alle informazioni a loro disponibili per fornire servizi agli utenti. La diffusione dell'IoT su così tante aree è la testimonianza di un interesse mondiale da parte di ricercatori appartenenti sia al mondo accademico che a quello industriale. La Ricerca ha portato alla nascita di tecnologie e protocolli progettati per rispondere ai diversi bisogni degli scenari emergenti, rendendo difficile sviluppare applicazioni interoperabili. Il Web of Things (WoT) è nato per rispondere a questi problemi tramite l'adozione degli standard che hanno favorito il successo del Web. Ma un contributo maggiore può venire dal Semantic Web of Things (SWoT). Infatti, i protocolli del Semantic Web permettono identificazione univoca delle risorse e una rappresentazione dei dati tale che le informazioni siano computabili e l'informazione di differenti fonti facilmente aggregabile. Le tecnologie del Semantic Web sono quindi degli interoperability enabler per l'IoT. Questa Tesi analizza come adottare le tecnologie del Semantic Web nell'IoT per realizzare la visione del SWoT di una rete di applicazioni interoperabile. Part I introduce l'IoT, Part II analizza gli algoritmi per supportare il publish-subscribe nei broker semantici e la loro implementazione in Smart-M3 e SEPA. Inoltre, viene presentato il lavoro preliminare verso il primo benchmark per applicazioni SWoT. Part IV discute l'applicazione dei risultati a diversi domini applicativi (mobilità elettrica, domotica, semantic audio ed Internet of Musical Things). Part V presenta le conclusioni sul lavoro svolto. La Ricerca su applicazioni semantiche ha evidenziato carenze negli attuali software di visualizzazione. Quindi, Part III presenta un nuovo metodo di rappresentazione delle basi di conoscenza semantiche basato sull’approccio a grafo che introduce il concetto di Semantic Plane