6809 research outputs found
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Tuttoscuola 558: Una squadra di educatori junior per la Ludoteca del Registro .it
No full textL\u27articolo descrive gli obiettivi e i contenuti del progetto di peer education Let\u27s Bit!, lanciato dalla Ludoteca dle Registro.it nell\u27anno 2015/1
Social Sensing. Dalla rete agli utenti e ritorno
No full textLe attuali piattaforme dei Social media consentono ogni giorno a milioni di persone di condividere informazioni e documentare eventi in tempo reale. ? possibile utilizzare gli utenti delle piattaforme Social come sensori da impiegare al verificarsi di eventi nel mondo reale? Nel caso di un disastro naturale, come di un attacco terroristico, sarebbe possibile richiedere agli utenti della rete presenti sul posto di scambiare nell?immediatezza informazioni sull\u27evento?Le attuali piattaforme dei Social media consentono ogni giorno a milioni di persone di condividere informazioni e documentare eventi in tempo reale. ? possibile utilizzare gli utenti delle piattaforme Social come sensori da impiegare al verificarsi di eventi nel mondo reale? Nel caso di un disastro naturale, come di un attacco terroristico, sarebbe possibile richiedere agli utenti della rete presenti sul posto di scambiare nell?immediatezza informazioni sull\u27evento
Can data mining help car sharing?
No full textMobility and congestion are critical concerns for every city, be it large or small,due to the economic and environmental challenges that they pose. Manyanalysts have advocated addressing these issues by encouraging newmultimodal services and fostering the deployment of more efficient ondemandmobility services. In this work, we focus on car sharing, a mode oftransportation that is gaining increasing popularity with its promise to reducetraffic congestion, parking demands and pollution in our cities. There are twomain classes of car sharing services: station-based car sharing or free floatingcar-sharing. In the former, shared vehicles are picked up and dropped off atdesignated (and reserved) locations within the service area, called stations. Infree floating car sharing, instead, cars can be picked up and dropped offanywhere within the service area, as long as parking is permitted at thatlocation. The two approaches have each advantages and disadvantages.Free floating car sharing offers a lot of flexibility to customers, but in citieswere finding a parking spot is troublesome, the reserved parking spaceoffered by station-based car sharing may appeal more
PLIERS: a popularity-based recommender system for content dissemination in online social networks
No full textOnline social networks (OSNs) allow users to generate items and tag or rate them in order to help others in the identification of useful content. In this paper, we propose a novel tag-based recommender system called PLIERS, able to identify useful contents based on users\u27 interests. It relies on the assumption that users are mainly interested in items and tags with similar popularity to those they already own. It reaches a good tradeoff between algorithmic complexity and the level of personalization of recommended items. To evaluate PLIERS, we performed a set of experiments on real OSN datasets, demonstrating that it outperforms the state-of-the-art solutions in terms of personalization, relevance, and novelty of recommendations
Next generation IEEE 802.11 Wireless Local Area Networks: Current status, future directions and open challenges
No full textA new generation of Wireless Local Area Networks (WLANs) will make its appearance in the market in the forthcoming years based on the amendments to the IEEE 802.11 standards that have recently been approved or are under development. Examples of the most expected ones are IEEE 802.11aa (Robust Audio Video Transport Streaming), IEEE 802.11ac (Very-high throughput at < 6 GHz), IEEE 802.11af (TV White Spaces) and IEEE 802.11ah (Machine-to-Machine communications) specifications. The aim of this survey is to provide a comprehensive overview of these novel technical features and the related open technical challenges that will drive the future WLAN evolution. In contrast to other IEEE 802.11 surveys, this is a use case oriented study. Specifically, we first describe the three key scenarios in which next-generation WLANs will have to operate. We then review the most relevant amendments for each of these use cases focusing on the additional functionalities and the new technologies they include, such as multi-user MIMO techniques, groupcast communications, dynamic channel bonding, spectrum databases and channel sensing, enhanced power saving mechanisms and efficient small data transmissions. We also discuss the related work to highlight the key issues that must still be addressed. Finally, we review emerging trends that can influence the design of future WLANs, with special focus on software-defined MACs and the internet-working with cellular systems
A framework for detecting unfolding emergencies using humans as sensors
No full textThe advent of online social networks (OSNs) paired with the ubiquitous proliferation of smartphones have enabled social sensing systems. In the last few years, the aptitude of humans to spontaneously collect and timely share context information has been exploited for emergency detection and crisis management. Apart from event-specific features, these systems share technical approaches and architectural solutions toaddress the issues with capturing, filtering and extracting meaningful information from data posted to OSNs by networks of human sensors. This paper proposes a conceptual and architectural framework for the design of emergency detection systems based on the ?human as a sensor? (HaaS) paradigm. An ontology for the HaaS paradigm in the context of emergency detection is defined. Then, a modular architecture, independent of a specific emergency type, is designed. The proposed architecture is demonstrated by an implemented application for detecting earthquakes via Twitter. Validation and experimental results based on messages posted during earthquakes occurred in Italy are reported
Angela R.: a familial Alzheimer\u27s disease case in the days of Auguste D.
No full textThe rebuilding of the N family, a large Italiankindred affected by early-onset autosomal dominant Alzheimer?sdisease (AD), provided an important contributionto the discovery of Presenilin 1 (PSEN1), the main generesponsible for familial AD. This pedigree was identifiedwith the help of medical records from the archives of thePsychiatric Hospital of Girifalco, Italy. The clinical recordof Angela R., an ancestor of the N family, dating back to1904, showed a clinical picture of Angela R., consistentwith a diagnosis of non-amnestic probable AD, matchingthe ??dysexecutive?? phenotype described in her descendants.The a posteriori diagnosis of AD is supported by theevidence of the causative genetic mutation PSEN1-Met146Leu as well as neuropathological AD features inher genealogically proven descendants. The clinical case ofAngela R. was recorded at the same time of Alzheimer?sdescription of Auguste D. Its discovery crucially contributedto the genealogical reconstruction of the N family,linking came from different branches, which until thenwere unrelated, to the same kindred. The archives of theGirifalco Hospital represented a valuable source of medicaland historical information and were essential to the research on Italian-American AD families that finally led tothe identification of new genes
Scale parameter selection for the spectral clustering method
No full textSpectral clustering is a powerful method for finding structure in data through the eigenvectors of a similarity matrix. It often out-performs traditional clustering algorithms such as k-means when the structure of the individual clusters is highly non-convex. Its accuracy depends on how the similarity between pairs of data points is defined. When a Gaussian similarity function is used, the choice of a scale parameter o is crucial. It is often suggested to select o by running the spectral algorithm repeatedly for different values of o and selecting the one that provides the best clustering according to some criterium. In this paper we propose a low cost technique for selecting a suitable o based on the minimal spanning tree (MST) associated to the graph of the distances between pairs of points. A numerical experimentation on both artificial and real-world datasets validates the effectiveness of the proposed technique
An example of smartphone Bluetooth Low Energy access control system
No full textThe massive diffusion of smartphone, tablets and the upcoming arrival of new wearable devices are fueling the need to find intelligent solutions to everyday problems, by simplifying and improving the use of things we are already accustomed to.Thanks to the processing power, wireless communication and networking available on our mobile devices, adopted by a growing number of people, it is possible to deliver advanced services to a multitude of users, even if they are not particularly experts in the IT field.This allows us to develop new paradigms of interaction human-to-objects.In this document it is described a prototype system, that employs technologies designed for mobile devices, to realize an access control system. Being well aware that commercial solutions already exist, the intent is to explore and demonstrate new features provided by the devices that we use daily