1,720,954 research outputs found
Enabling Location-aware Operation in Decentralized IoT Communications
Full text linkWe present an efficient design to enable location-aware operation
in decentralized IoT communications. Large-scale IoT systems rep-
resent the backbone of a smart city functioning, allowing pervasive
environmental sensing across devices and networks. However, ex-
isting IoT communication systems are largely driven by data types
and miss out on embracing data location, which is fundamental in
environment sensing. To address this issue, we demonstrate it is
possible to efficiently embed a notion of location within the Zenoh
protocol. We make it possible to steer message routing based on
both data type and location, yet without altering the existing rout-
ing core and message forwarding, unlike most existing solutions.
We also present three encoding techniques for location data, each of
them representing a different trade-off between expressiveness and
performance overhead. Our evaluation uses a virtualized environ-
ment and real-world packet traces of heterogeneous networks. We
show, for example, that our design decreases the average message
latency by more than 50% when routing data also based on location,
while increasing throughput, compared to two different baselines
Enabling location-aware operation in decentralized IoT communications
Full text linkLAUREA MAGISTRALEAl centro di un’infrastruttura IoT si trovano i protocolli di comunicazione. Tra i vari proposti in letteratura, il modello Publish/Subscribe (Pub/Sub) è il più diffuso, con diverse implementazioni documentate. Zenoh, un protocollo recentemente emerso, adotta il paradigma Pub/Sub implementando anche il modello Request/Response, supportando architetture decentralizzate, assicurando la tolleranza agli errori e eliminando la necessità di un broker o server. Inoltre, offre il supporto a storage distribuiti e la capacità di eseguire query, integrando la produzione, la memorizzazione, l’utilizzo e la richiesta dei dati, ma attualmente non implementa meccanismi location-aware, ovvero non è in grado di effettuare sottoscrizioni basate sia sui dati che sulla posizione di origine degli stessi. Per affrontare il problema di associare i dati rilevati da sensori alle rispettive posizioni di rilevamento sia per le fonti stazionarie che in movimento, garantendo l’indipendenza tra i due aspetti, abbiamo progettato e implementato una variante location-aware di Zenoh. Abbiamo introdotto una chiave all’interno del topic contenente i dati geografici codificati. Abbiamo introdotto un componente di match per i dati geografici che disaccoppia il processo di matching gestendoli esternamente. Ciò ci consente di iniettare solo i risultati del match geografico nel core di Zenoh senza apportare modifiche alla logica del protocollo né al processo di routing, garantendo le prestazioni e le funzionalità della versione originale. Questa soluzione ci permette di manipolare il routing dei messaggi gestendo coordinate geografiche e forme geografiche complesse, definendo regole di matching della posizione indipendentemente dal resto del topic. Il nostro approccio ci ha consentito l’implementazione di tre tecniche di codifica, ciascuna un compromesso tra prestazioni ed espressività nella descrizione dei dati geografici.
La soluzione è efficace nel suddividere logicamente la rete in base alle zone geografiche, filtrando i messaggi, migliorando le prestazioni e riducendo la latenza di oltre il 50%. Inoltre, forniamo una tecnica di codifica che, rispetto alle altre, dimostra prestazioni superiori del 40%, rendendola adatta per reti congestionate, lente e con risorse limitate.At the heart of an IoT distributed infrastructure lie communication protocols. Literature presents various communication models and message patterns tailored to different use cases. Among these, the Publish/Subscribe (Pub/Sub) message model stands out as widely utilized, with several publicly available protocols. Zenoh, a recently emerged protocol, adopts a Pub/Sub topic-based paradigm unifying also the Request/Response model. It employs a fully decentralized architecture, ensuring fault tolerance and eliminating the necessity for a central broker. It also supports geo-distributed storage and query capabilities, harmonizing data in motion, in use, and at rest, but it currently lacks location-awareness capabilities. Zenoh is not able to perform subscriptions based on both the data and the location where these data originate.
To address the challenge of associating sensed data with their respective sensing locations for both stationary and moving sources, ensuring independence between the two aspects, we design and implement a location-aware variant of Zenoh. This involves introducing a unique key within the topic structure for conveying geographic encoded data. We introduce a location matching component decoupling the matching process and managing location data externally. This lets us just inject location-based matching results in Zenoh’s core and we do not need to make changes in the protocol logic nor in the routing process, guaranteeing performance and functionality of the original version. This solution allows us to pilot message routing managing complex geographical shapes and coordinates, defining location matching rules independently of the rest of the topic. Our approach enables the implementation of three encoding techniques, each of them with a distinct tradeoff between performance and expressiveness in describing geographical data. Our location-aware version of Zenoh demonstrates to create a logical partition of the network according to geographical zones, filtering unnecessary messages, enhancing performance, and reducing latency by more than 50%. In addition, we provide an encoding technique that performs 40% better than the others, making it suitable for congested, slow, and resource-constrained networks
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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