1,721,024 research outputs found
Performance Evaluation Suite for Semantic Publish-Subscribe Message-oriented Middlewares
No full textThe emerging Internet of Things paradigm is driving the industry and the research towards Information and Communication Technologies (ICT) scenarios supporting high heterogeneity and interoperability. We claim that software architectures based on Semantic Publish-Subscribe Message-Oriented Middlewares (SPS-MoMs) are a powerful approach to address the requirements of such scenarios. While benchmarks and frameworks are available to evaluate the performance of MoMs, Semantic Web tools (i.e., SPARQL endpoints and RDF stores) and publish-subscribe systems, there are still no de-facto standards for the evaluation of SPS-MoMs, due to the novelty of this approach. In this paper, we propose Performance Evaluation Suite (PES), a benchmarking framework aimed at retrieving relevant performance indicators about a generic SPS-MoM. The feasibility of the proposed approach is proved by using PES to compare different implementations of a Semantic Information Broker (SIB), the core component of a SPS-MoM named Smart-M3
Mapping the NGSI-LD Context Model on Top of a SPARQL Event Processing Architecture: Implementation Guidelines
Get PDFNGSI-LD is an open specification released by ETSI which proposes an information model and an API for an easy to use and standard management of context information. The NGSI-LD information model is framed within an ontology and adopts JSON-LD as serialization format for context information. This paper presents an approach to the implementation of the NGSI-LD specification over a SPARQL Event Processing Architecture. This work is being developed within the European-Brasilian H2020 SWAMP project focused on implementing an Internet of Things platform providing services for smart water management in agriculture
Development of collaborative editing applications through semantic publish-subscribe platforms
No full textCloud computing revolutionized the way resources (i.e. services and data) are accessed and used. Among the many changes in data processing and service provision paradigms, Software as a Service (SaaS) and collaborative editing are two of the most significant. This paper presents an approach based on semantic publish/subscribe paradigm to the development of collaborative editing applications. The main aim of this research work consists in exploiting emerging technologies (i.e. semantic web data representation formalisms, publish-subscribe platforms) in order to (1) overcome limitations coming from the traditional paradigm of single-author workflows, (2) enhance the editing capabilities of the users, (3) ease the development and maintainment of applications and (4) provide a shared high- level abstraction of the documents that fosters information-level interoperability and reusability. The proposed approach is then validated through an ad-hoc vector graphics application, SCEd (Semantic Collaborative Editor) built upon a SPARQL Event Processing Architecture derived from the Smart-M3 semantic publish-subscribe platform
A multi-broker platform for the internet of things
No full textThe emerging paradigm of the Internet of Things with millions of devices dynamically interconnected to share data brings in new requirements for applications and infrastructures. New challenges raise in terms of connectivity, resource discovery and support for multidomain distributed applications. Furthermore, the connection parameters of involved devices may dynamically change over time and must be properly discovered. This paper proposes a multi broker platform (MBP) built on top of an existing interoperability platform, Smart-M3. MBP enables the original platform to manage multi-domain scenarios. Furthermore it provides a semantic mechanism for context-broker discovery and a virtualization interface to reach remote nodes
A modular lightweight implementation of the Smart-M3 semantic information broker
No full textInteroperability among heterogeneous devices is one of the main topics investigated nowadays to realize the Ubiquitous Computing vision. Smart-M3 is a software architecture born to provide interoperability through the Semantic Web technologies and reactivity thanks to the publish-subscribe paradigm. In this paper we present a new implementation in Python of the central component of the Smart-M3 architecture: the Semantic Information Broker (SIB). The new component, named pySIB, has been specifically designed for embedded or resource constrained devices. pySIB represents a new open source lightweight and portable SIB implementation, but also introduces new features and interesting performances. JSON has been introduced as the default information encoding notation as it offers the flexibility of XML with minor bandwidth requirements. Memory allocation on disk and at runtime is in the order of Kilobytes i.e. minimal, if compared with the other reference implementations. Performance tests on existing (SP2B) and ad-hoc benchmarks point out possible improvements but also encouraging data such as the best insertion time among the existing SIB implementations
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
A Semantic Publish-Subscribe Architecture for the Internet of Things
Get PDFThis paper presents a publish-subscribe architecture designed to support information level interoperability in smart space applications in the Internet of Things (IoT). The architecture is built on top of a generic SPARQL endpoint where publishers and subscribers use standard SPARQL Updates and Queries. Notifications about events [i.e., changes in the resource description framework (RDF) knowledge base] are expressed in terms of added and removed SPARQL binding results since the previous notification, limiting the network overhead and facilitating notification processing at subscriber side. A novel event detection algorithm, tailored on the IoT specificities (i.e., heterogeneous events need to be detected and continuous updates of few RDF triples dominate with respect to more complex updates), is presented along with the envisioned application design pattern and performance evaluation model. Eventually, a reference implementation is evaluated against a benchmark inspired by a smart city lighting case. The performance evaluation results show the capability to process up to 68k subscriptions/s triggered by simple single-lamp updates and up to 3.8k subscriptions/s triggered by more complex updates (i.e., 10 to 100 lamps)
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