Ontology-Based Consistent Specification of Sensor Data Acquisition Plans in Cross-Domain IoT Platforms

Nowadays there is an high number of IoT applications that seldom can interact with each other because developed within different Vertical IoT Platforms that adopt different standards. Several efforts are devoted to the construction of cross-layered frameworks that facilitate the interoperability among cross-domain IoT platforms for the development of horizontal applications. Even if their realization poses different challenges across all layers of the network stack, in this paper we focus on the interoperability issues that arise at the data management layer. Specifically, starting from a flexible multi-granular Spatio-Temporal-Thematic data model according to which events generated by different kinds of sensors can be represented, we propose a Semantic Virtualization approach according to which the sensors belonging to different IoT platforms and the schema of the produced event streams are described in a Domain Ontology, obtained through the extension of the well-known Semantic Sensor Network ontology. Then, these sensors can be exploited for the creation of Data Acquisition Plans by means of which the streams of events can be filtered, merged, and aggregated in a meaningful way. A notion of consistency is introduced to bind the output streams of the services contained in the Data Acquisition Plan with the Domain Ontology in order to provide a semantic description of its final output. When these plans meet the consistency constraints, it means that the data they handle are well described at the Ontological level and thus the data acquisition process over passed the interoperability barriers occurring in the original sources. The facilities of the StreamLoader prototype are finally presented for supporting the user in the Semantic Virtualization process and for the construction of meaningful Data Acquisition Plans

Efficient all-optical production of large 6^6Li quantum gases using D1_1 gray-molasses cooling

We use a gray molasses operating on the D$_1$ atomic transition to produce degenerate quantum gases of $^{6}$Li with a large number of atoms. This sub-Doppler cooling phase allows us to lower the initial temperature of 10$^9$ atoms from 500 to 40 $\mu$K in 2 ms. We observe that D$_1$ cooling remains effective into a high-intensity infrared dipole trap where two-state mixtures are evaporated to reach the degenerate regime. We produce molecular Bose-Einstein condensates of up to 5$\times$10$^{5}$ molecules and weakly-interacting degenerate Fermi gases of $7\times$10$^{5}$ atoms at $T/T_{F}<0.1$ with a typical experimental duty cycle of 11 seconds.Comment: 5 pages, 3 figure

Exploring the ferromagnetic behaviour of a repulsive Fermi gas via spin dynamics

Ferromagnetism is a manifestation of strong repulsive interactions between itinerant fermions in condensed matter. Whether short-ranged repulsion alone is sufficient to stabilize ferromagnetic correlations in the absence of other effects, like peculiar band dispersions or orbital couplings, is however unclear. Here, we investigate ferromagnetism in the minimal framework of an ultracold Fermi gas with short-range repulsive interactions tuned via a Feshbach resonance. While fermion pairing characterises the ground state, our experiments provide signatures suggestive of a metastable Stoner-like ferromagnetic phase supported by strong repulsion in excited scattering states. We probe the collective spin response of a two-spin mixture engineered in a magnetic domain-wall-like configuration, and reveal a substantial increase of spin susceptibility while approaching a critical repulsion strength. Beyond this value, we observe the emergence of a time-window of domain immiscibility, indicating the metastability of the initial ferromagnetic state. Our findings establish an important connection between dynamical and equilibrium properties of strongly-correlated Fermi gases, pointing to the existence of a ferromagnetic instability.Comment: 8 + 17 pages, 4 + 8 figures, 44 + 19 reference

Connecting dissipation and phase slips in a Josephson junction between fermionic superfluids

We study the emergence of dissipation in an atomic Josephson junction between weakly-coupled superfluid Fermi gases. We find that vortex-induced phase slippage is the dominant microscopic source of dissipation across the BEC-BCS crossover. We explore different dynamical regimes by tuning the bias chemical potential between the two superfluid reservoirs. For small excitations, we observe dissipation and phase coherence to coexist, with a resistive current followed by well-defined Josephson oscillations. We link the junction transport properties to the phase-slippage mechanism, finding that vortex nucleation is primarily responsible for the observed trends of conductance and critical current. For large excitations, we observe the irreversible loss of coherence between the two superfluids, and transport cannot be described only within an uncorrelated phase-slip picture. Our findings open new directions for investigating the interplay between dissipative and superfluid transport in strongly correlated Fermi systems, and general concepts in out-of-equlibrium quantum systems.Comment: 6 pages, 4 figures + Supplemental Materia

Participatory Design and ICT for Fostering ADHD Students&#8217; Inclusion

This paper illustrates a project proposal focused on adopting participatory design of ICT-based educational activities for improving the inclusion of ADHD students in classrooms

End-user development for smart environments (EUD4SE)

Preface

Metaservizi per la produzione collaborativa di moduli didattici in ambienti sociali = Social metaservices for the collaborative production of learning modules

In queste pagine si introduce una piattaforma a servizio degli usuali Learning Management Systems (LMS) per consentirne un utilizzo facile e proficuo da parte dei docenti di un determinato settore. Nello specifico la piattaforma costituisce il supporto informativo a un ampio progetto di promozione dell\u2019educazione all\u2019imprenditorialit\ue0 lanciato dalla Comunit\ue0 Europea. La chiave di volta \ue8 costituta dai metadati con cui sono descritti i suoi contenuti. Questi metadati sono alla base delle procedure d\u2019interrogazione e raccomandazione, nonch\ue9 di altre azioni \u201csocial\u201d sulle quali i docenti possono contare per reperire il materiale su cui fondare i corsi che intendono erogare. In tal prospettiva la piattaforma s\u2019identifica con una social network per utenti esigenti, appunto i docenti, che si aspettano di reperire nel sistema materiali autorevoli e appropriati, essendo capaci di valutarne tali aspetti e al contempo desiderosi di venire guidati nella loro ricerca all\u2019interno dell\u2019ampio repertorio messo a disposizione dalla piattaforma.In this paper we introduce a platform designed to help educators make profitable use of current LMSs for teaching in a particular domain. The platform has been developed within a major European Commission funded project for the promotion of Entrepreneurship Education (EE). The conceptual core of the platform is the metadata for describing content. These metadata form the basis for query and recommender systems, as well as for other socially oriented services designed to help teachers retrieve suitable material for their courses. Seen in this light, the platform is a social network for a very demanding user group, namely teachers. They use the environment as a means to locate material considered authoritative and appropriate, and at the same time seek platform support for searching the system\u2019s considerable repository

User-Centered Event Data Modelling and Analytics

Conventional data analytics platforms are not adequate to be applied in the management of emergency situations. The 3V the usually characterize big data (volume, variety, velocity) along with the issue of integrating information coming from heterogeneous networks require the development of new systems. In this paper we provide the design of a data analytics platform that we are developing around the concept of event, that is simple or complex data stream gathered from physical and social sensors that are encapsulated with contextual information (space, time, thematics). Copyright \ua9 2014 for the individual papers by the papers' authors

Past&Present at Tarchna&Tarquinia: a flexible approach to make visible the invisible

This contribution falls within the topic of the “development of guidelines and best practices” and deals with the study case of the ancient Etruscan city of Tarchna (Tarquinia, central Italy). The “Tarquinia Project” started here in 1982 with the investigations carried out by the Università degli Studi di Milano in two sacred areas and along the fortifications. The Project was endowed since its beginnings with the collaboration of several experts in disciplines other than Archaeology which number has increased in the past years. Their aim is to find out as much as possible about the material aspects of Archaeology to decode their relationship with the invisibility of ancient life. This contribution aims at presenting our approach addressed to put scholars in the condition to handle data according to their own procedures, within the same environment, through an ecosystem of benchmarks and references in ways close to the individual practices, supported by ICTs. This is meant to avoid the use of predetermined terminologies and categories, enhancing the proper methods of every single discipline involved in a multidisciplinary environment, beyond the current work of every individual scholar. We propose a radical change of perspective, starting from the collection of raw data in several fields (material aspects of Archaeology, Geoarchaeology, Architecture, Topography) to grasp the underlining model, thanks to the assessment of recurrent associations among different categories of evidence, instead of starting from preconceived theoretic models and using data to confirm them. Distinct small, medium and large scale investigation methods are integrated for the first time to produce a significant interdisciplinary cognitive tool to shift from the materiality of the leftovers of Ancient Past, to its integrity, to what lies behind at a metaphysical level and is, therefore, invisible to us. This is related to the materiality of rituals, based on the recurrence of cultic practices in the above-mentioned sacred areas, whose gestures might also be revealed by sediments and organic remains, in addition to other archaeological and epigraphic issues. Tarquinia strongly challenges researchers to be open to unconventional and unexploited issues due to the complexity of the site. It is the ideal place to create awareness among the general public about the results of Archaeological research and to disseminate and make visible its acquirements, according to the European Charter for Researchers. The support of Environmental Psychologists helps to ensuring outreach entails initiatives directed to the local population, in order to introduce them to an equilibrated connection between their invisible Past and the local present culture. In this framework students from high school are involved in the Archaeological field activities, since 2012. Our best practices are therefore addressed to give back to the ancient Etruscan city its value of prominent cultural and natural landmark in the Past, to make it possible for the modern community to assess it in the same way. According to current theories of “place identity” and "place attachment" the modern community is in the condition to feeling and experiencing the continuity between past, present and future