1,720,971 research outputs found
Towards better scalability for IoT-cloud interactions via combined exploitation of MQTT and CoAP
No full textIt is manifest the growing research and industrial interest in scalable solutions for the efficient integration of large amounts of deployed sensors and actuators (Internet of Things - IoT-devices) and cloud-hosted virtualized resources for elastic storage and processing (including big data online stream processing). Such relevant attention is also demonstrated by the emergence of interesting IoT-cloud platforms from industry and open-source communities, as well as by the flourishing research area of fog/edge computing, where decentralized virtual resources at edge nodes can support enhanced scalability and reduced latency via locality-based optimizations. In this perspective, this paper proposes an innovative distributed architecture combining machine-to-machine industry-mature protocols (i.e., MQTT and CoAP) in an original way to enhance the scalability of gateways for the efficient IoT-cloud integration. In addition, the paper presents how we have applied the approach in the practical experience of efficiently and effectively extending the implementation of the open-source gateway that is available in the industry-oriented Kura framework for IoT
Feasibility of fog computing deployment based on docker containerization over RaspberryPi
No full textFog computing is strongly emerging as a relevant and interest-attracting paradigm+technology for both the academic and industrial communities. However, architecture and methodological approaches are still prevalent in the literature, while few research activities have specifically targeted so far the issues of practical feasibility, cost-effectiveness, and efficiency of fog solutions over easily-deployable environments. In this perspective, this paper originally presents i) our fog-oriented framework for Internet-of-Things applications based on innovative scalability extensions of the open-source Kura gateway and ii) its Docker-based containerization over challenging and resource-limited fog nodes, i.e., RaspberryPi devices. Our practical experience and experimental work show the feasibility of using even extremely constrained nodes as fog gateways; the reported results demonstrate that good scalability and limited overhead can be coupled, via proper configuration tuning and implementation optimizations, with the significant advantages of containerization in terms of flexibility and easy deployment, also when working on top of existing, off-the-shelf, and limited-cost gateway nodes
A migration-enhanced edge computing support for mobile devices in hostile environments
No full textFirst research activities are starting to recognize the suitability of edge computing approaches in several Internet-of-Things (IoT) and Cyber-Physical Systems (CPS) application domains, for instance, to better address scalability issues and to improve reactivity via local control decisions and actuation. The paper originally proposes the design and implementation of an extended edge computing platform, specifically designed for the support of mobile services when provisioned in so-called hostile environments. In particular, our original platform is capable of proactive migration of virtualized functions in response to provision-time device mobility. The paper provides a practical contribution in terms of design and implementation of proactive migration as an extension of the Elijah platform, available for the community of researchers/practitioners in the field. In addition, the paper contributes with lessons learnt from deployment and experimentation, including experimental results about the performance achievable when adopting simple but effective strategies for proactive migration
Integrating mobile internet of things and cloud computing towards scalability: lessons learned from existing fog computing architectures and solutions
No full textThe primary objective of this paper is to present a fresh overview of the very recent literature about the integration of mobile internet of things (MIoT) and cloud computing towards scalability, by specifically concentrating on solutions based on the exploitation of edge computing capabilities (fog computing) to effectively integrate device localities with the global cloud resources. In addition to surveying the state-of-the-art of fog computing for MIoT and cloud integration, the paper will propose an original architecture and classification of possible solutions in the field, by reporting lessons learned from the few existing experiences and by shedding new light on specific sub-fields of research where advancements are needed to effectively integrate huge numbers of geographically dispersed mobile devices and globally available cloud resources
Elastic Provisioning of Internet of Things Services Using Fog Computing: An Experience Report
No full textThe adoption of cloud and fog computing techniques for elastic provisioning of quality-constrained industrial Internet of Things (IoT) services is largely envisioned as very promising, but experience reports and lessons learned from real deployment still lack. To fill this gap, this paper presents and reports the evaluation of a system consisting of virtual services in a combined fog, cloud, and IoT setting, made up of multiple devices with varying computation capabilities. In particular, we have utilized and integrated off-the-shelf solutions into our architecture and have experimentally investigated the benefits of virtualization to move and redeploy mobile components to the fog nodes closest to the targeted end devices. In addition, the paper proposes an original solution to dynamically scale and provision the resources for the fog computing layer by using geometric monitoring. The reported results show the feasibility and efficiency of the proposed exploitation of both fog and cloud virtualized resources to enable scalability in the domain of IoT-assisted mobile presence services
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Straightforward synthesis of chiral non-racemic α-boryl isocyanides
Get PDFA straightforward concise synthesis of chiral non-racemic aliphatic alpha-boryl isocyanides, relay intermediates for boron-based bioactive molecules in multicomponent reactions, is presented. The short synthetic sequence comprises as key steps copper-catalysed asymmetric borylation of imines, simultaneous nitrogen formylation/boron-protecting group interconversion and the final formamide dehydration reaction
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