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Publications

Publications by CSE

2020

Next generation of microservices for the 5G Service-Based Architecture

Authors
Moreira, JB; Mamede, H; Pereira, V; Sousa, B;

Publication
INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT

Abstract
The architecture for 5G core includes a Service-Based Architecture for the diverse network functions (NFs), which relies on HTTP/2 for the SBI and TCP as the underlying transport protocol. The specifications of the HTTP family is moving towards more efficient and secure protocols, which are based on UDP to assure enhanced transport but using TLS to secure the communication channel. The next generation of microservices needs to be more secure, performant and easily manageable, where HTTP/3 and containers orchestration platforms (like Kubernetes) can provide significative contributions towards such goals. Different deployment approaches can be followed for services implemented in compliance to the 5G SBA. This paper contributes with the assessment of deployment models for services in 5G networks, where NFs are implemented following traditional architectures (all the functions in a VM) or as serverless architectures (with functions distributed in containers). The performance of microservices in Kubernetes is also evaluated. The evaluation conducted also considers the employment of different versions of HTTPs to empower the service-based interfaces of 5G services. Results demonstrate performance benefits of employing HTTP/3, based on QUIC protocol, in scenarios with networks characterised by losses or delay conditions. Despite such gain, deployment in 5G networks needs to carefully consider aspects related with connection tracking mechanisms to support high volumes of requests.

2020

Ubiquitous Framework for High Quality Audiovisual Production

Authors
Andrade, MT; Santos, P; Costa, TS; Freitas, L; Golestani, S; Viana, P; Rodrigues, J; Ulisses, A;

Publication
Proceedings - 2020 TRON Symposium, TRONSHOW 2020

Abstract
The media sector is constantly evolving and, in the last few years, such evolution has been driven by a number of convergence paradigms, notably, that between broadband and broadcast technologies with the introduction of IT and IP technology. The present trend is to switch totally from a closed niche that uses highly specialized equipment to off-the-shelf IT-centric solutions, offering easy configuration and remote operation. The aim is to enable common computers to be turned into highly capable media devices and act as connected objects adopting an IoT-like paradigm. This vision, though, is not implemented easily, given that most media industry professionals do not yet feel comfortable operating in the IT technology space and also due to the stringent requirements that exist in this industry. The Joint Task Force on Networked Media is defining specifications that aim at overcoming such existing barriers. In this article we present a novel solution that follows the guidelines delivered by this group to set up a remotely operated media production facility, totally based on IP and IT technology, constituting a step forward the realization of the IoT concept in professional media environments. The focus is on two complementary components, namely, the GUI Agent and the MW Agent, which are not covered by the defined specifications but that are crucial to speed up the deployment of concrete solutions that can be easily operated by non-IT and non-IP experts in a transparent and ubiquitous way. © 2020 TRON Forum.

2020

Uncovering literacy practices in the game total war: Shogun 2 with a contract-agency model

Authors
Neves, PP; HEI-Lab, Lusófona University,; Morgado, L; Zagalo, N; Universidade Aberta,; INESC TEC,; CIAC,; LE@D,; Universidade de Aveiro, DigiMedia,;

Publication
International Journal of Film and Media Arts

Abstract
This paper showcases how the Contract Agency Model can be used to uncover literacy practices in videogame’s own terms as a complement to existing, more ‘indirect’ games literacies, using as an example the videogame Total War: Shogun 2. The paper first situates the Contract Agency Model within approaches to videogames and within approaches to media literacy. The paper then identifies three interesting literacy practices in the videogame, which also exemplify the eight levels of abstraction of the Contract Agency Model. The paper concludes by discussing the model’s implications to media literacy and videogames, namely that videogames effect a second-order mutual signaling with their players – agency as a conversation of commitment to meaning – that is humanizing of those players, and that the model can uncover this as an im-plicit contract of bio-costs, as a ‘direct’ literacy of videogames, i.e. a literacy in videogames’ own terms. © 2020 BY-NC-ND.

2020

Unifying Parsing and Reflective Printing for Fully Disambiguated Grammars

Authors
Zhu, ZR; Ko, HS; Zhang, YZ; Martins, P; Saraiva, J; Hu, ZJ;

Publication
NEW GENERATION COMPUTING

Abstract
Language designers usually need to implement parsers and printers. Despite being two closely related programs, in practice they are often designed separately, and then need to be revised and kept consistent as the language evolves. It will be more convenient if the parser and printer can be unified and developed in a single program, with their consistency guaranteed automatically. Furthermore, in certain scenarios (like showing compiler optimisation results to the programmer), it is desirable to have a more powerful reflective printer that, when an abstract syntax tree corresponding to a piece of program text is modified, can propagate the modification to the program text while preserving layouts, comments, and syntactic sugar. To address these needs, we propose a domain-specific language BiYacc, whose programs denote both a parser and a reflective printer for a fully disambiguated context-free grammar. BiYacc is based on the theory of bidirectional transformations, which helps to guarantee by construction that the generated pairs of parsers and reflective printers are consistent. Handling grammatical ambiguity is particularly challenging: we propose an approach based on generalised parsing and disambiguation filters, which produce all the parse results and (try to) select the only correct one in the parsing direction; the filters are carefully bidirectionalised so that they also work in the printing direction and do not break the consistency between the parsers and reflective printers. We show that BiYacc is capable of facilitating many tasks such as Pombrio and Krishnamurthi's 'resugaring', simple refactoring, and language evolution.

2020

Message from the General Chairs: SBAC-PAD 2020

Authors
Areias, M; Barbosa, J; Dutra, I;

Publication
Proceedings - Symposium on Computer Architecture and High Performance Computing

Abstract

2020

Profiling IT Security and Interoperability in Brazilian Health Organisations From a Business Perspective

Authors
Rui, RJ; Martinho, R; Oliveira, AA; Alves, D; Nogueira Reis, ZSN; Santos Pereira, C; Correia, ME; Antunes, LF; Cruz Correia, RJ;

Publication
INTERNATIONAL JOURNAL OF E-HEALTH AND MEDICAL COMMUNICATIONS

Abstract
The proliferation of electronic health (e-Health) initiatives in Brazil over the last 2 decades has resulted in a considerable fragmentation within health information technology (IT), with a strong political interference. The problem regarding this issue became twofold: 1) there are considerable flaws regarding interoperability and security involving patient data; and 2) it is difficult even for an experienced company to enter the Brazilian health IT market. In this article, the authors aim to assess the current state of IT interoperability and security in hospitals in Brazil and evaluate the best business strategy for an IT company to enter this difficult but very promising health IT market. A face-to-face questionnaire was conducted among 11 hospital units to assess their current status regarding IT interoperability and security aspects. Global Brazilian socio-economic data was also collected, and helped to not only identify areas of investment regarding health IT security and interoperability, but also to derive a business strategy, composed out of recommendations listed in the paper.

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