Local: Sala Multiuso CIC
Horário: 14h
Palestrante: Marco Figueiredo Junior (doutorando)
Orientador: Profa. Alba Melo
Título: Parallel Comparison of Huge DNA Sequences in Multiple GPUs with Pruning
Resumo:Sequence comparison is a task usually performed in several Bioinformatics applications daily all over the world. Algorithms that retrieve the optimal result have quadratic time complexity, requiring a huge amount of computing power when the sequences compared are long. In order to reduce the execution time, many parallel solutions have been proposed in the literature in the last decades. Nevertheless, depending on the sizes of the sequences, even those parallel solutions take hours or even days to complete. Pruning techniques can significantly improve the performance of the parallel solutions and a few approaches have been proposed to provide pruning capabilities for GPU solutions. However, they are restricted to one or two GPUs. This paper proposes and evaluates a variant of the block pruning approach that runs in multiple GPUs, in homogeneous or heterogeneous environments. Experimental results obtained with real DNA sequences in two GPU testbeds (4 NVidia Tesla P100 and NVidia GTX 680 + NVidia GTX 980 Ti) show that significant performance gains are achieved when block pruning is enabled when comparing to its non-block pruning counterpart (up to 1.36x in the homogeneous environment and 1.81x in the heterogeneous environment), achieving a performance of 694.8 GCUPS (Billions of Cells Updated per Second).
Horário: 14h30
Palestrante: Gustavo Jardim Portella (doutorando)
Orientador: Profa. Alba Melo
Título:Utility-based Strategy for Balanced Cost and Availability at the Cloud Spot Market
Resumo:In the Amazon EC2 cloud provider, the price of spot instances is much lower than on demand instances, however, at the cost of availability issues of the former. Recently, several strategies were proposed to analyze the Amazon EC2 spot pricing model employing techniques such as statistical and probabilistic modeling and neural networks. To the best of our knowledge, there is no work in the literature that can accurately capture the trade-off between price and availability in favor of user decision-making. In this work, we propose and evaluate a utility-based strategy that balances spot instance cost and availability to Amazon EC2 users. Our experiments show that the average availability reaches up to 98% for spot instances, using data gathered from Amazon (September to November 2016), and a bid value below 28% of the on demand price for the m4.10xlarge general purpose instance type..
Horário: 15h
Palestrante: Luis Henrique Vieira Amaral (mestrando)
Orientador: Prof. Rodrigo Bonifácio
Título: What the source code evolution could tell us about errors?
Resumo:.Almost every software is built in a Collaborative development environment, in which tasks are distributed to the developers, who work separately, on their local machine. After the task is done, the project is updated and pushed to the remote repository to be available for other contributors. While parallel working increases software productivity, on the other hand, concurrent changes might cause merge conflicts. Even with the availability of good version control Systems, that prevents developers to submit changes when merge conflicts could not be automatically resolved, some bugs might appear after a merge is completed. Many studies involving merge operation and conflicts were conducted but there are some open questions about whether or not merges induce bugs. In addition, even though it is known that co-change dependencies cause bad-smells to the software, it still remains a lack of information about them to induce bugs. The purpose of this research is to investigate the historical information of open source java projects in order to verify bug-introducing changes (BIC). By doing this we are going to use a well-known algorithm named SZZ, collect information from issue tracking system and combine with git log to find the list of BICs. Finally we will verify if commits with co-change dependencies and merge commits are blamed by SZZ to be a bug-introducing commit.
Horário: 15h30
Palestrante: Cristoffer Leite da Silva (mestrando)
Orientador: Profa. Priscila Solis
Título: Modelo de Análise de Desempenho para Funções de Redes Virtualizadas em 5G
Resumo:Proposta e desenvolvimento de uma arquitetura dinâmica com o objetivo de analisar o desempenho de funções de rede virtualizadas e verificar o cumprimento dos SLAs em uma rede 5G.
Profa Célia Ghedini Ralha (Este endereço de email está sendo protegido de spambots. Você precisa do JavaScript ativado para vê-lo.)
Coordenadora dos Seminários de Pós-Graduação em Informática 2019-2