Gustavo Callou

Dr. Gustavo Callou


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2009
Verified
Conference Paper
Closed access
EAErmeson Andrade
Ermeson Andrade
PMPaulo Maciel
Paulo Maciel
GCGustavo Callou
Gustavo Callou
BNBruno Nogueira
Bruno Nogueira
In this paper we use the Activity diagram of the System Modeling Language (SysML) in combination with the new UML profile for Modeling and Analysis of Real-Time and Embedded systems (MARTE) in order to validate functional, timing and low power requirements in early phases of the embedded system development life-cycle. However, SysML lacks a formal semantics and hence it is not possible to apply, directly, mathematical techniques on SysML models for system validation. Thus, a novel approach for automatic translation of SysML Activity diagram into Time Petri Net with Energy constraints (ETPN) is proposed. In order to depict the practical usability of the proposed method, a case study is presented, namely, pulse-oximeter. Besides, the estimates obtained (execution time and energy consumption) from the model are 95% close to the respective measures obtained from the real hardware platform.

8 January 2014 in Energies
Verified
Journal Article
Open access
PDF file
GCGustavo Callou
Gustavo Callou
JFJoao Ferreira
Joao Ferreira
PMPaulo Maciel
Paulo Maciel
DTDietmar Tutsch
Dietmar Tutsch
RSRafael Souza
Rafael Souza
Data centers have evolved dramatically in recent years, due to the advent of social networking services, e-commerce and cloud computing. The conflicting requirements are the high availability levels demanded against the low sustainability impact and cost values. The approaches that evaluate and optimize these requirements are essential to support designers of data center architectures. Our work aims to propose an integrated approach to estimate and optimize these issues with the support of the developed environment, Mercury. Mercury is a tool for dependability, performance and energy flow evaluation. The tool supports reliability block diagrams (RBD), stochastic Petri nets (SPNs), continuous-time Markov chains (CTMC) and energy flow (EFM) models. The EFM verifies the energy flow on data center architectures, taking into account the energy efficiency and power capacity that each device can provide (assuming power systems) or extract (considering cooling components). The EFM also estimates the sustainability impact and cost issues of data center architectures. Additionally, a methodology is also considered to support the modeling, evaluation and optimization processes. Two case studies are presented to illustrate the adopted methodology on data center power systems.

2 February 2017 in Computing
Verified
Journal Article
Closed access
PDF file
EAErmeson Andrade
Ermeson Andrade
BNBruno Nogueira
Bruno Nogueira
RMRubens Matos
Rubens Matos
GCGustavo Callou
Gustavo Callou
PMPaulo Maciel
Paulo Maciel


1 March 2013 in Sustainable Computing: Informatics and Systems
Verified
Journal Article
Closed access
BSB. Silva
B. Silva
GCGustavo Callou
Gustavo Callou
ETEduardo Tavares
Eduardo Tavares
PMPaulo Maciel
Paulo Maciel
JFJ. Figueiredo
J. Figueiredo
Francisco NevesFrancisco Neves
Francisco Neves

9 November 2018 in IEEE Latin America Transactions
Verified
Journal Article
Closed access
RYR. R. Yadav
R. R. Yadav
Erica Teixeira Gomes De SousaErica Teixeira Gomes De Sousa
Erica Teixeira Gomes De Sousa
GCGustavo Callou
Gustavo Callou
Containers emerged as a new alternative to the virtual machines in large enterprise systems due to their virtualization mechanism that demands a low utilization level of the computational resources. Performance evaluation of Containers and virtual machines provides to practitioners and system administrators information about the quality of the services provisioned for virtualization. The main goal of this paper is to conduct a comparative study of the performance evaluation of virtual machines and containers. In order to accomplish this, a methodology is proposed to evaluate the performance of Docker containers and virtual machines. Additionally, a real-world case study is presented to illustrate the applicability of the proposed approach. For all the experiments, the Docker container shown lower execution times for the requests against virtual machine.