De Moura Xavier J.C.,CETESB Sao Paulo State Environment Company |
De Andrade Azevedo I.,Aeronautics Institute of Technology ITA |
De Sousa Junior W.C.,Aeronautics Institute of Technology ITA |
Nishikawa A.,CETESB Sao Paulo State Environment Company
Environmental Monitoring and Assessment | Year: 2013
Atmospheric pollutant monitoring constitutes a primordial activity in public policies concerning air quality. In São Paulo State, Brazil, the São Paulo State Environment Company (CETESB) maintains an automatic network which continuously monitors CO, SO2, NO x, O 3, and particulate matter concentrations in the air. The monitoring process accuracy is a fundamental condition for the actions to be taken by CETESB. As one of the support systems, a preventive maintenance program for the different analyzers used is part of the data quality strategy. Knowledge of the behavior of analyzer failure times could help optimize the program. To achieve this goal, the failure times of an ozone analyzer - considered a repairable system - were modeled by means of the nonhomogeneous Poisson process. The rate of occurrence of failures (ROCOF) was estimated for the intervals 0-70,800 h and 0-88,320 h, in which six and seven failures were observed, respectively. The results showed that the ROCOF estimate is influenced by the choice of the observation period, t 0 = 70,800 h and t 7 = 88,320 h in the cases analyzed. Identification of preventive maintenance actions, mainly when parts replacement occurs in the last interval of observation, is highlighted, justifying the alteration in the behavior of the inter-arrival times. The performance of a follow-up on each analyzer is recommended in order to record the impact of the performed preventive maintenance program on the enhancement of its useful life. © 2012 Springer Science+Business Media B.V.
de Medeiros-Junior R.A.,Aeronautics Institute of Technology ITA |
de Lima M.G.,Aeronautics Institute of Technology ITA |
de Medeiros M.H.F.,Polytechnic University of Mozambique
Environment, Development and Sustainability | Year: 2015
Chloride is one of the main factors responsible for damages related to the corrosion of the concrete reinforcement in marine environments. It is known that this mechanism of degradation is directly related to environmental variables. Within this context, it can be inserted the global climate change. This paper deals with the effects of temperature and relative humidity changes on the service life of concrete structures affected by chloride attack. This way, three situations of environmental aggressiveness were simulated: past, current, and future. Then, models for predicting the chlorides penetration were analyzed to the three selected situations. So, a practical methodology is presented, and the results are consistent with the literature data. Among the results, it can be noted that changes in temperature and relative humidity identified in a period of 100 years were responsible for a reduction from 7.8 to 10.2 years of service life. Most standards provide a design service life of 50 years for reinforced concrete structures. © 2014, Springer Science+Business Media Dordrecht.
Silveira F.F.,Federal University of São Paulo |
Da Cunha A.M.,Aeronautics Institute of Technology ITA |
Lisboa M.L.,Federal University of Rio Grande do Sul
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014
Aspect-Oriented Software Development is a contemporary technique of software development that aims to improve the separation of concerns issues faced by traditional approaches. It improves the modularity of crosscutting concerns into units called aspects. However, this feature raises concerns about the quality of aspect-oriented programs (AOP). Existing functional testing approaches do not directly investigate the aspect composition problem, its resultant interactions and representation on a dynamic model. This paper describes a state-based testing method for AOP that targets class-aspect and aspect-aspect faults. To support the developed method, we introduce a model to represent the dynamic behavior of aspects interactions, a strategy to derive testing sequences, and a testing tool. Results of our assessment show that the approach is capable of detecting faults based on fault-models available in the literature. Furthermore, it is able to reveal another source of faults on AOPs, the aspect composition fault. © 2014 Springer International Publishing.
Panasiewicz J.,National Institute for Space Research |
Pacheco G.M.,Aeronautics Institute of Technology ITA
SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference Proceedings | Year: 2015
This article presents a photonic circuit that achieves direct carrier BPSK modulation of a RF signal from an opto-electronic oscillator suitable for satellite telemetry and control. The circuit was implemented with two Mach-Zehnder optical modulators. The optical wavelength is 1550 nm. One modulator was used to construct an optoelectronic oscillator to generate a carrier with frequency equal to 2.5 GHz. The second modulator was used to perform the BPSK direct modulation of the carrier signal. A bit rate of 1 Mbps was used and an EVM of 9.6% was obtained. The diagrams of the optoelectronic circuits and the modulation measurements are displayed. © 2015 IEEE.
Alarcon J.E.G.,Aeronautics Institute of Technology ITA |
Loureiro G.,Aeronautics Institute of Technology ITA
Advanced Concurrent Engineering | Year: 2013
This paper analyzes the strategic innovation of a real company, which will be called "The Leader Company" for reasons of privacy and fairness, and verifies its performance in the aerospace industry in Sao Jose dos Campos - SP, particularly Avibras Aerospace SA, the Command for Aerospace Technology (DCTA), the Brazilian Aeronautics Enterprise SA (EMBRAER) and the National Institute for Space Research (INPE). It is concluded that "The Leader Company" constantly reinvents itself and has a strong strategy of corporate acquisitions and partnerships in order to rely on expertise from within and outside the company. It was also concluded that its performance in the aerospace industry in Sao Jose dos Campos is very early, and also the use of "The Leader Company" solutions in the companies verified, are still underdeveloped, thus, opportunities for "The Leader Company" on those institutions. © Springer-Verlag London 2013.
Da Silva Jacinto A.,Aeronautics Institute of Technology ITA |
De Oliveira J.M.P.,Aeronautics Institute of Technology ITA
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering | Year: 2012
Problem solving requires a lot of work for selecting and organizing resources and information, as well as defining the best solution approaches. In the case of ill-structured problems (ISP), due to the possibility of several potential solutions, the task becomes harder. Group work can better support this task but requires cognitive tools in order to allow the registration and the recovery of data about the problem and the exchange of ideas. This paper presents a process to support solving ISP, using ontology and software tools in order to facilitate the group work. Preliminary experiments indicate the feasibility of the process. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering.
Scatolini F.,Aeronautics Institute of Technology ITA |
Alves C.J.P.,Aeronautics Institute of Technology ITA |
Eller R.D.A.G.,Aeronautics Institute of Technology ITA
Applied Acoustics | Year: 2016
This paper presents the difficulties found in trying to apply the "Balanced Approach" concept of ICAO (UN-International Civil Aviation Organization) on the noise pollution mitigation at urban Brazilian airports using, as a case study, the Congonhas Airport. It has been discussed by means of alternative operating scenarios, how to make the concept more flexible, aiming to bring the benefit of any additional acoustic comfort, without diminishing the installed capacity and already limited for environmental reasons. The results show that there are conditions for improvement, since there are both awareness of all players involved and permanent and real-time noise monitoring, even if those mitigating measures are not reflected on the noise annoyance models currently adopted for the land use planning. © 2015 Elsevier Ltd. All rights reserved.
Battagello V.A.,Aeronautics Institute of Technology ITA |
Ribeiro C.H.,Aeronautics Institute of Technology ITA
Studies in Computational Intelligence | Year: 2015
To perform cooperative tasks in a decentralized manner, multi-robot systems are often required to communicate with each other. For that reason, maintaining the communication graph connectivity is a fundamental issue. In this paper, we analyse the effects of communication time delay upon a connectivity maintenance control strategy for robotic agents. The results show that the connectivity strategy is resilient to the negative effects of such disturbance only at small values in the communication delay. However, the inherent inertial characteristics of most terrestrial and aquatic robots opens the perspective of applying the connectivity maintenance strategy to adaptive schemes that consider, for instance, autonomous adaptation to constraints other than the connectivity itself, e.g. communication efficiency and energy harvesting. © Springer International Publishing Switzerland 2015.
Alves A.D.,Aeronautics Institute of Technology ITA |
Yanasse H.H.,Federal University of São Paulo |
Soma N.Y.,Aeronautics Institute of Technology ITA
Scientometrics | Year: 2016
Journal Citation Reports (JCR) is the main source of bibliometric indicators known by the scientific community. This paper presents the results of a study of the distributions of the first and second significant digits according to Benford’s law (BL) of the number of articles, citations, impact factors, half-life and immediacy index bibliometric indicators in journals indexed in the JCR Sciences and Social Sciences Editions from 2007 to 2014. We also performed the data analysis to country’s origin and by journal’s category, and we verified that the second digit has a better adherence to BL. The use of the second digit is important since it provides a more sound, complete and consistent analysis of the bibliometric indicators. © 2016 The Author(s)
Vieira B.,Aeronautics Institute of Technology ITA
Ambiente e Sociedade | Year: 2015
Advances in water management require knowledge of the availability and demand of water resources to define priority actions for water conservation. The aim of this study is to support the development of municipal initiatives involving Water Footprint, based on a case study of Caraguatatuba, using 2012 data. The following water footprints were considered: a) the urban water system; b) sewage production; c) cattle-farming; and d) rural water uses. Results showed water footprint levels of approximately 400 Mm3/year, where grey water represents the largest share (85%). Furthermore, results showed that the increased pressure on local water resources results from the disparity between the sewage system in relation to the demands of a growing population. This study can contribute to improve Water Footprint methodology, promoting comparative studies and supporting water management policies in this socio-political field.