Publications

Publications by HASLab

2020

Measuring Icebergs: Using Different Methods to Estimate the Number of COVID-19 Cases in Portugal and Spain

Authors
Baquero, C; Casari, P; Anta, AF; Frey, D; Garcia-Agundez, A; Georgiou, C; Menezes, R; Nicolaou, N; Ojo, O; Patras, P;

Publication

Abstract
AbstractThe world is suffering from a pandemic called COVID-19, caused by the SARS-CoV-2 virus. The different national governments have problems evaluating the reach of the epidemic, having limited resources and tests at their disposal. Hence, any means to evaluate the number of persons with symptoms compatible with COVID-19 with reasonable level of accuracy is useful. In this paper we present the initial results of the @CoronaSurveys project. The objective of this project is the collection and publication of data concerning the number of people that show symptoms compatible with COVID-19 in different countries using open anonymous surveys. While this data may be biased, we conjecture that it is still useful to estimate the number of infected persons with the COVID-19 virus at a given point in time in these countries, and the evolution of this number over time. We show here the initial results of the @CoronaSurveys project in Spain and Portugal.

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2020

Causality is Graphically Simple

Authors
Baquero, C;

Publication
CoRR

Abstract

2020

State-Machine Replication for Planet-Scale Systems (Extended Version)

Authors
Enes, V; Baquero, C; Rezende, TF; Gotsman, A; Perrin, M; Sutra, P;

Publication
CoRR

Abstract

2020

CoronaSurveys: Using Surveys with Indirect Reporting to Estimate the Incidence and Evolution of Epidemics

Authors
Ojo, O; Agundez, AG; Girault, B; Hernández, H; Cabana, E; García, AG; Arabshahi, P; Baquero, C; Casari, P; Ferreira, EJ; Frey, D; Georgiou, C; Goessens, M; Ishchenko, A; Jiménez, E; Kebkal, O; Lillo, R; Menezes, R; Nicolaou, N; Ortega, A; Patras, P; Roberts, JC; Stavrakis, E; Tanaka, Y; Anta, AF;

Publication
CoRR

Abstract

2020

Age-Partitioned Bloom Filters

Authors
Shtul, A; Baquero, C; Almeida, PS;

Publication
CoRR

Abstract

2020

SPELLing out energy leaks: Aiding developers locate energy inefficient code

Authors
Pereira, R; Carcao, T; Couto, M; Cunha, J; Fernandes, JP; Saraiva, J;

Publication
JOURNAL OF SYSTEMS AND SOFTWARE

Abstract
Although hardware is generally seen as the main culprit for a computer's energy usage, software too has a tremendous impact on the energy spent. Unfortunately, there is still not enough support for software developers so they can make their code more energy-aware. This paper proposes a technique to detect energy inefficient fragments in the source code of a software system. Test cases are executed to obtain energy consumption measurements, and a statistical method, based on spectrum-based fault localization, is introduced to relate energy consumption to the source code. The result of our technique is an energy ranking of source code fragments pointing developers to possible energy leaks in their code. This technique was implemented in the SPELL toolkit. Finally, in order to evaluate our technique, we conducted an empirical study where we asked participants to optimize the energy efficiency of a software system using our tool, while also having two other groups using no tool assistance and a profiler, respectively. We showed statistical evidence that developers using our technique were able to improve the energy efficiency by 43% on average, and even out performing a profiler for energy optimization.

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