1,720,957 research outputs found
Enhancing Blockchain-Based Processes with Decentralized Oracles
No full textThe automation of business processes via blockchain-based systems allows for trust, reliability and accountability of execution. The link that connects modules that operate within the on-chain sphere and the off-chain world is key as processes often involve the handling of physical entities and external services. The components that create that link are named oracles. Numerous studies on oracles and their implementations are arising in the literature. Nevertheless, their availability, integrity and trust could be undermined if centralized architectures are adopted, as taking over an oracle could produce the effect of a supply-chain attack on the whole system. Solutions are emerging that overcome this issue by turning the architecture underneath the oracles into a distributed one. In this paper, we investigate the design and application of oracles, distinguishing their adoption for the in-flow or out-flow of information and according to the initiator of the exchange (hence, pull- or push-based)
A Blockchain-driven Architecture for Usage Control in Solid
No full textDecentralization initiatives like Solid enable data owners to control who has access to their data and to stimulate innovation by creating both application and data markets. Once data owners share their data with others, though, it is no longer possible for them to control how their data are used. To address this issue, we propose a usage control architecture to monitor compliance with usage control policies. To this end, our solution relies on blockchain and trusted execution environments. We demonstrate the potential of the architecture by describing the various workflows needed to realize a motivating use case scenario for data markets. Additionally, we discuss the merits of the approach from privacy, security, integrateability, and affordability perspectives
Trusted Execution Environment for Decentralized Process Mining
Get PDFInter-organizational business processes involve multiple independent organizations collaborating to achieve mutual interests. Process mining techniques have the potential to allow these organizations to enhance operational efficiency, improve performance, and deepen the understanding of their business based on the recorded process event data. However, inter-organizational process mining faces substantial challenges, including topical secrecy concerns: The involved organizations may not be willing to expose their own data to run mining algorithms jointly with their counterparts or third parties. In this paper, we introduce CONFINE, a novel approach that unlocks process mining on multiple actors’ process event data while safeguarding the secrecy and integrity of the original records in an inter-organizational business setting. To ensure that the phases of the presented interaction protocol are secure and that the processed information is hidden from involved and external actors alike, our approach resorts to a decentralized architecture comprised of trusted applications running in Trusted Execution Environments (TEEs). We show the feasibility of our solution by showcasing its application to a healthcare scenario and evaluating our implementation in terms of memory usage and scalability on real-world event logs
Blockchain based Resource Governance for Decentralized Web Environments
Get PDFDecentralization initiatives such as Solid and ActivityPub aim to give data
owners more control over their data and to level the playing field by enabling
small companies and individuals to gain access to data, thus stimulating
innovation. However, these initiatives typically employ access control
mechanisms that cannot verify compliance with usage conditions after access has
been granted to others. In this paper, we extend the state of the art by
proposing a resource governance conceptual framework, entitled ReGov, that
facilitates usage control in decentralized web environments. We subsequently
demonstrate how our framework can be instantiated by combining blockchain and
trusted execution environments. Through blockchain technologies, we record
policies expressing the usage conditions associated with resources and monitor
their compliance. Our instantiation employs trusted execution environments to
enforce said policies, inside data consumers' devices.} We evaluate the
framework instantiation through a detailed analysis of requirements derived
from a data market motivating scenario, as well as an assessment of the
security, privacy, and affordability aspects of our proposal
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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