We are the Navigators, a research team on distributed systems, their architectures, their algorithms, in their several skins: fault tolerance, real-time, security, and combinations thereof.
We also pursue the quest for the right balance between science and technology. Some people say that Informatics (a.k.a. computer science and engineering) belongs to a new breed, of what are called techno-sciences. We believe that techno-scientists should accompany theoretical mastery with a deep knowledge of their environment — computer technology — as well as astro-physicists know the sky, or marine biologists know the sea.
We study new theories to explain distributed systems, and new algorithms to take advantage from them. But we also like to do proof-of-concept experiments about the theory we work on. We try that our papers and theses tell a good story as clearly as possible. We work hard for our demonstrations to be convincing and captivating. Because we believe science is made for others.
Our greatest riches are our culture, and our researchers and students. If you believe in the former, you can become one of the latter. Welcome!
- (1/Feb/2015) A new European project has started, called SUPERCLOUD - User-Centric Management of Security and Dependability in Cloud of Clouds
- (1/Oct/2014) A new European project has started, called SEGRID - Security for smart Electricity GRIDs
- João Inácio, Ibéria Medeiros, “Effectiveness on C Flaws Checking and Removal (fast abstract)”, in In Proceedings of the 52nd IEEE/IFIP International Conference on Dependable Systems and Networks (DSN'22), Jun. 2022.
- Claudio Martins, Ibéria Medeiros, “Generating Quality Threat Intelligence Leveraging OSINT and a Cyber Threat Unified Taxonomy”, ACM Transactions on Privacy and Security, vol. 25-3, no. 19, May 2022.
- João Inácio, “Automatic Removal of Flaws in Embedded System Software”, Master’s thesis, Mestrado em Segurança Informática, Departamento de Informática, Faculdade de Ciências da Universidade de Lisboa, May 2022.
- Nuno Durão, “Discovery of Web Attacks by Inspecting HTTPS Network Traffic with Machine Learning and Similarity Search”, Master’s thesis, Mestrado em Segurança Informática, Departamento de Informática, Faculdade de Ciências da Universidade de Lisboa, May 2022.
- João Caseirito, “Attacking Web Applications for Dynamic Discovering of Vulnerabilities”, Master’s thesis, Mestrado em Segurança Informática, Departamento de Informática, Faculdade de Ciências da Universidade de Lisboa, Feb. 2022.
- André Gil, “Platform architecture and data management for cloud-based buildings energy self-assessment and optimization”, Master’s thesis, Faculdade de Ciências, Universidade de Lisboa, Jan. 2022.
- Ibéria Medeiros, Nuno Neves, Miguel Correia, “Statically Detecting Vulnerabilities by Processing Programming Languages as Natural Language”, IEEE Transactions on Reliability, Jan. 2022.
- Vasco Leitão, “Prioritization of Software and System Requirements through Natural Language Processing for Testing Software”, Master’s thesis, Mestrado em Ciência em Dados, Nov. 2021.
- Ricardo Mendes, Tiago Oliveira, Vinicius Vielmo Cogo, Nuno Ferreira Neves, Alysson Bessani, “CHARON: A Secure Cloud-of-Clouds System for Storing and Sharing Big Data”, IEEE Transactions on Cloud Computing, vol. 9, no. 4, pp. 1349–1361, Oct. 2021.
- Vinicius Vielmo Cogo, Alysson Bessani, “Brief Announcement: Auditable Register Emulations”, in 35th International Symposium on Distributed Computing (DISC 2021), Oct. 2021.
Friday, 2015-Feb-12, 11h30-12h00, room C6.3.38
Title: Projeto de rede WAN – estudo de caso: rede do Exército Brasileiro
Abstract: O estudo de caso a ser apresentado se trata de uma parte da Rede de Longa Distância (Wide Area Network - WAN) do Exército Brasileiro, na qual caracteriza-se por ser, em cada Ponto de Presença instalado em Organização Militar específica, um pacote de serviços de dados, voz e vídeo, por meio de uma rede IP multisserviços, em MPLS, de abrangência nacional, para o tráfego de informações corporativas
Title: An Efficient MapReduce Middleware to Tolerate Cloud Faults
Abstract: Applications such as web search and social networking have been moving from centralized to decentralized cloud architectures to improve their scalability. MapReduce, a programming framework for processing large amounts of data using thousands of machines in a single cloud, also needs to be scaled out in multiple distributed clouds to adapt to this architecture evolution.
In this navtalk, I will present an Hadoop proxy that allows MapReduce computation to scale out to multiple clouds and to tolerate cloud faults. Our solution addresses three challenges. First, it does not require any modification to the Hadoop framework. Second,the proposed system tolerates arbitrary and malicious faults, as well as cloud outages. Third, it achieves cloud fault tolerance at reasonable cost by guaranteeing minimum replication and scheduling replicated jobs to clouds that minimize the expected jobcompletion time.