General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/userguides/explore-bristol-research/ebr-terms/ 1932-4537 (c)Abstract-Datacenter (DC) design has been moved towards the edge computing paradigm motivated by the need of bringing cloud resources closer to end users. However, the Software Defined Networking (SDN) architecture offers no clue to the design of Micro Datacenters (MDC) for meeting complex and stringent requirements from next generation 5G networks. This is because canonical SDN lacks a clear distinction between functional network parts, such as core and edge elements. Besides, there is no decoupling between the routing and the network policy. In this paper, we introduce Residue Defined Networking Architecture (RDNA) as a new approach for enabling key features like ultra-reliable and low-latency communication in MDC networks. RDNA explores the programmability of Residues Number System (RNS) as a fundamental concept to define a minimalist forwarding model for core nodes. Instead of forwarding packets based on classical table lookup operations, core nodes are tableless switches that forward packets using merely remainder of the division (modulo) operations. By solving a residue congruence system representing a network topology, we found out the algorithms and their mathematical properties to design RDNA's routing system that (i) supports unicast and multicast communication, (ii) provides resilient routes with protection for the entire route, and (iii) is scalable for 2-tier Clos topologies. Experimental implementations on Mininet and NetFPGA SUME show that RDNA achieves 600 ns switching latency per hop with virtually no jitter at core nodes and submillisecond failure recovery time.

Abstract-Widespread adoption of Web technologies, particularly in professional and educational areas, has motivated new research efforts with the objective of designing new interaction mechanisms based on Web technologies. Within this framework, collaborative Web browsing (cobrowsing) aims at extending currently available Web browsing capabilities in order to allow several users to "browse together" on the Web. Such a browsing paradigm can have many useful applications, for instance, in e-learning, for collaboratively searching and retrieving documents, and for online assistance (helpdesk). A cobrowsing system should provide all the facilities required for allowing users to establish and release, in a very simple and flexible way, browsing synchronization relations as well as interactions with continuous media presentations embedded within Web pages. This paper presents the design, modeling, and implementation of the cobrowsing system called CoLab. CoLab provides all the functionalities required for allowing users to collaboratively browse the Web, and a first experimental version of the tool has been implemented and is fully operational.

A arborização urbana constitui elemento de suma importância para a obtenção de níveis satisfatórios de qualidade de vida. No entanto, poucas cidades brasileiras possuem planejamento efetivo para arborização. A presente pesquisa teve como intuito realizar uma avaliação quali-quantitativa da arborização de cinco praças públicas do município de Jerônimo Monteiro, Espírito Santo. Nas praças analisadas foram amostrados 50 indivíduos distribuídos em 13 espécies e seis famílias botânicas. As espécies que tiveram maior frequência relativa na arborização foram Licania tomentosa (Benth.) Fritsch (52%) e Terminalia catappa L. (12%). Três das cinco praças tiveram valores acima do recomendado para o Índice de Densidade Arbórea (IDA) e apenas duas para o Índice de Sombreamento Arbóreo (ISA). Observou-se a presença de interações ecológicas na maioria dos indivíduos arbóreos, principalmente de liquens, indicando uma boa qualidade do ar e baixa poluição atmosférica. Indivíduos com fitossanidade e qualidade de copa regular ou ruim foram encontrados em todas as praças, sendo mais evidente onde ocorre a espécie L. tomentosa. Em geral, a arborização das praças precisa de melhorias que incluem a implantação de mais espécies nativas, preferencialmente regionais, e manejo da poda que mantenha as características morfométricas específicas da copa das árvores.

Real‐time and mission‐critical applications for Industry 4.0 demand fast and reliable communication. Therefore, knowing devices' location is essential, but GPS is of little use indoors, whereas electromagnetic impairments and interferences demand new approaches to ensure reliability. The challenges include real‐time feedback with end‐to‐end (E2E) low latency; high data density due to large number of IoT devices per area; and smaller communication cells, which increases the handover frequency and complexity. To tackle these issues, we introduce a programmable intelligent space (PIS) to deploy attocells, enable E2E programmability, and provide a precise computer vision localization system and networking programmability based on software‐defined networking. To validate our approach, experiments were conducted, controlling a mobile robot through a trajectory. We demonstrate the need for higher camera frame rate to achieve tighter precision, evaluating different trade‐offs on localization, bandwidth, and latency. Results have shown that PIS wireless attocell handover achieves seamlessly mobile communication, delivering packets within the deadline window, with similar performance to a no handover baseline.

Abstract. As collaboration activities usually involve several people with different group tasks and needs, they are rarely supported by a single CSCW technology. Then different types of collaborative applications are usually applied in order to support group work. But in spite of being used to accomplish a common collaboration task, these applications are executed independently without getting any advantage of each other. The integration of such applications would allow them to dynamically interoperate, combining their different functionalities in a controlled way. In order to achieve integration, we propose LEICA 1 , a loosely-coupled integration environment which allows collaborative applications to interact without loosing their autonomy. LEICA relies on Web services technology, event notification system, and collaboration policies for controlling the interactions between integrated applications.

With the growing demand for collaboration technologies, several CSCW (Compute-Supported Cooperative Work) systems have been developed. CVEs (Collaborative Virtual Environments) represent an important category of CSCW systems that generally make use of 3D shared space to provide collaboration facilities. However in most CVEs collaboration is restricted to the Virtual Reality context. In this paper it is proposed to extend CVEs through the integration of different collaboration tools in order to allow collaboration to take place in different contexts (e.g. Web browsing), in a parallel and coordinated way with the virtual scene.

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