1,721,061 research outputs found
Semantic-based distributed ledger technology for pervasive cyber-physical systems
Get PDFL'evoluzione dei sistemi cyberfisici (Cyber-Physical System, CPS) e delle Distributed Ledger Technology (DLT) rappresenta un passo significativo nella progettazione di infrastrutture sicure e intelligenti in diversi ambiti, tra cui l'industria manifatturiera, le smart city e l'Internet of Thing (IoT). Con l'integrazione sempre più stretta delle capacità computazionali dei sistemi CPS con i processi fisici, diventa essenziale una gestione dei dati robusta, trasparente e decentralizzata. Le DLT, in particolare la blockchain, offrono una soluzione garantendo l'integrità dei dati e abilitando interazioni sicure peer-to-peer, risultando ideali per soddisfare i requisiti di fiducia e visibilità delle informazioni negli ambienti CPS.
In questo contesto, la tesi presenta un framework basato su tecnologie semantiche per integrare le DLT nei sistemi CPS, sfruttando il Semantic Web of Thing (SWoT) per migliorare il processo decisionale, la gestione delle risorse e il ragionamento automatico nei sistemi decentralizzati. L'architettura proposta affronta sfide chiave come scalabilità, sicurezza e interoperabilità, combinando le DLT con tecnologie semantiche per consentire ai dispositivi con risorse limitate di eseguire compiti complessi di ragionamento localmente, mantenendo l'integrità e la fiducia dei dati a livello di sistema.
I principali contributi del framework includono: (1) un layer di knowledge representation che supporta il resource discovery avanzato e la selezione dei servizi ottimizzata mediante ragionamento automatico; (2) un modello di apprendimento federato che abilita l'addestramento sicuro e decentralizzato dei modelli tra dispositivi edge e IoT, preservando la privacy dei dati e ottimizzando l'efficienza della rete; e (3) un componente blockchain arricchito semanticamente che utilizza smart contract e matchmaking semantico per gestire e prioritizzare dinamicamente le risorse. Una validazione sperimentale approfondita, inclusa un'applicazione pratica sulla mobilità sostenibile per veicoli elettrici, dimostra l'applicabilità del framework a scenari reali di CPS, evidenziando miglioramenti nella gestione dei dati, nella scalabilità e nell'utilizzo delle risorse.The evolution of Cyber-Physical Systems (CPSs) and Distributed Ledger Technologies (DLTs) marks a significant step forward in building secure and intelligent infrastructures across various domains, including manufacturing, smart cities, and the Internet of Things (IoT). As CPS systems increasingly integrate computational capabilities with physical processes, the need for robust, transparent, and decentralized data management becomes essential. DLTs, particularly blockchain, provide a solution by ensuring data integrity and enabling secure peer-to-peer interactions, making it ideal for supporting the trust and information visibility requirements of CPS environments.
In this context, this dissertation presents a semantic-based framework for integrating DLTs into CPSs, leveraging the Semantic Web of Things (SWoT) to enhance decision-making, resource management, and automated reasoning within decentralized systems. The proposed architecture addresses key challenges in scalability, security, and interoperability by combining DLTs with semantic technologies to enable resource-constrained devices to perform complex reasoning tasks locally while preserving data integrity and trust across the system.
The framework’s primary contributions include: (1) a knowledge representation layer that supports advanced resource discovery and service selection through automated reasoning; (2) a federated learning model that enables secure, decentralized model training across edge and IoT devices, preserving data privacy and optimizing network efficiency; and (3) a semantic-enhanced blockchain mechanism that utilizes smart contracts and semantic matchmaking to dynamically manage and prioritize resources across the continuum. Extensive experimental validation, including a case study on green mobility for electric vehicles, demonstrates the framework’s applicability to real-world CPS scenarios, showcasing improvements in data handling, scalability, and resource utilization
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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