1,720,968 research outputs found
WoT Store: Managing Resources and Applications on the Web of Things
Full text linkThe chaotic growth of the Internet of Things (IoT) determined a fragmented landscape with a huge number of devices, technologies and platforms available on the market, and the consequential issues of interoperability on many system deployments. The Web of Things (WoT) architecture recently proposed by the W3C consortium constitutes a novel solution to enable interoperability across IoT platforms and application domains. At the same time, in order to see an effective improvement, a wide adoption of the W3C WoT solutions from the academic and industrial communities is required; this translates into the need of well-defined and complete support tools easing the deployment of W3C WoT applications. In this paper, we meet such requirement by proposing the WoT Store, a novel platform for managing and easing the deployment of Things and applications on the W3C WoT. The WoT Store allows the dynamic discovery of the resources available in the environment, i.e. the Things, and to interact with each of them through a dashboard, by visualizing their properties, executing commands or observing the notifications produced. In addition, similar to popular app stores, the WoT Store allows the search and execution of third-party WoT applications that interact with the available Things again in a seamless way. We validate the operations of our framework with two evaluation studies. First, through a small-case testbed, we demonstrate the Thing discovery and the possibility to run WoT applications that orchestrate the operations of multiple, heterogeneous Wireless Sensor Networks (WSNs). Second, through a mixed real/simulated large-scale crowdsensing scenario, we demonstrate the scalability of the platform, and the possibility to aggregate and visualize the data-streams produced by the WoT applications with minimal efforts for the users
Indoor Location Services through Multi-Source Learning-based Radio Fingerprinting Techniques
No full textProximity advertising, smart parking and tourism are just examples of use-cases of location-based services that have become extremely popular in the last few years, also thanks to the pervasive diffusion of GNSS-enabled mobile devices. These devices, however, are not able guarantee adequate accuracy in indoor scenarios, that represent the actual frontier of next-generation location-based services. To this aim, we present in this paper Wireless Locator (WI-LO), a novel framework for the indoor localization of smartphone devices and the automation of location-based tasks. Through the WI-LO Web portal, users can import an indoor planimetry, set the Reference Points (RPs), and define the actions to execute at each RP or region or RPs. The WI-LO localization engine implements hybrid Radio Finger-Printing (RF) techniques, and it leverages on a variety of sensors embedded in Commercial Off The Shelf (COTS) smartphones (Wi-Fi, BLE, LTE, magnetometer). We investigate the utilization of Machine Learning (ML) techniques for the processing of the radio fingerprints of each source, and the application of fusion policies in order to aggregate the hard-decisions of each source. The evaluation analysis, conducted at the DISI@UNIBO department, confirms the ability of the WI-LO platform to deliver geo-fencing messages with over 90% accuracy, and it investigates the impact of different ML techniques, application parameters and scenario settings on the overall localization performance
LOCATE: A LoRa-based mObile emergenCy mAnagement sysTEm
No full textDuring the occurrence of an emergency, being it the consequence of a natural disaster or of human activities, the pervasiveness of user-owned mobile devices (e.g. smartphones, tablets) turns into a precious help to convey data and services to all the people involved. As a result, several emergency-related mobile applications have been proposed on the market; however, they are often limited by the networking capabilities of the devices, since they are often based on short-range Device-to-Device (D2D) communication technologies (e.g. the Wi-Fi Direct), or on the cellular infrastructure, which might be not available on the emergency scenario. In this paper, we attempt to overcome both such issues, by proposing a novel Emergency Communication System (ECS) which operates over infrastructure-less phonebased networks, and guarantees long-range D2D communication thanks to the LoRa technology. The system, named LOCATE, includes a mobile application, through which users can convey minimal yet vital emergency-related data, and a dissemination protocol, spreading the emergency requests over multi-hop LoRA links. The performance of LOCATE have been evaluated through: (i) an experimental study, assessing the capability of LoRa technology to convey short, emergency messages over long distances, and a (ii) simulation study, demonstrating the effectiveness of the dissemination protocol on large-scale scenarios when compared to state-of-the-art flooding schemes
Practical Indoor Localization via Smartphone Sensor Data Fusion Techniques: A Performance Study
No full textAccurate indoor localization constitutes a challenging yet fundamental research problem towards the large-scale deployment of next-generation mobile indoor location-based services. This paper addresses two key issues of indoor localization: (i) how to take benefit of the presence of inertial sensors, short-range and long-range radio interfaces on modern smartphones in order to achieve fine-grained localization and trajectory tracking, and-at the same time-(ii) how to perform it while limiting the impact on energy-constrained devices. To address the first issue, we propose a novel hybrid strategy which implements a dual-step fusion process, i.e., it merges the estimations produced by pattern matching algorithms applied to short-range and long-range wireless sources available on smartphones and then it merges the estimations produced by Pedestrian Dead Reckoning (PDR) and Radio Fingerprinting (RF) techniques, in order to overcome the limitations of each approach. For the second issue, we describe the design and implementation of a novel client-server architecture, which offloads the computational expensive tasks to the infrastructure, while still guaranteeing acceptable localization lag. Finally, a modular, extensive evaluation is proposed on real-world scenarios, quantifying the impact of each sensor/source on the localization accuracy, and the gain induced by the dual-step fusion process over basic PDR localization techniques
WoT Store: Enabling Things and Applications Discovery for the W3C Web of Things
No full textThe Web of Things (WoT) architecture recently proposed by the W3C working group constitutes a promising approach to handle interoperability issues among heterogeneous devices and platforms, by semantically describing interfaces and interaction patterns among the Things. One of the main advantage of the W3C architecture is the possibility to decouple the description of the Things' behavior from their implementation and communication strategies, hence greatly simplifying the deployment of novel applications and services on top of it. Starting from such state-of-art, and envisioning a Web of seamlessly interacting W3C Things, this paper focuses on the next steps, i.e.: how to effectively support the discovery of Things? and: how to ease the distribution of applications running on Things? We answer to both the questions above through the proposal of the WOT STORE, a novel software platform supporting the distribution, discovery and installation of applications for the W3C WoT. The WOT STORE allows users to perform semantic discovery of the available Things, to search for compatible applications available on the market, and to install them over the target devices, all within the same framework. We describe the platform architecture and its proof-of-concept implementation, providing two alternative interfaces to interact with our tool: a Web portal, and new modules developed for the popular Node,-RED platform. Finally, we discuss two realistic use-cases of the WOT STORE for industrial IoT and home automation systems, remarking theadvantages of our solution in terms of deployment costs and interoperability support
Deploying W3C Web of Things-Based Interoperable Mash-up Applications for Industry 4.0: A Testbed
No full textIn Industry 4.0 scenarios, novel applications are enabled by the capability to gather large amount of data from pervasive sensors and to process them in order to devise the “digital twin” of a physical equipment. The heterogeneity of hardware sensors, communication protocols and data formats constitutes one of the main challenge toward the large-scale adoption of the Internet of Things (IoT) paradigm on industrial environments. To this purpose, the W3C Web of Things (WoT) group is working on the definition of some reference standards intended to describe in a uniform way the software interfaces of IoT devices and services, and hence to achieve the full interoperability among different IoT components regardless of their implementation. At the same time, due also to the recent appearance of the WoT W3C draft, few testbed and real-world deployments of the W3C WoT architecture has been proposed so far in the literature. In this paper, we attempt to fill such gap by describing the realization of a WoT monitoring application of a generic indoor production site: the system is able to orchestrate the sensing operations from three heterogeneous Wireless Sensor Networks (WSNs). We describe how the components of the W3C WoT architecture have been instantiated in our scenario. Moreover, we demonstrate the possibility to decouple the mash-up policies from the network functionalities, and we evaluate the overhead introduced by the WoT approach
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
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