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The Conference on Precision Electromagnetic Measurements (CPEM) 2014 was held at Windsor Barra Hotel in Rio de Janeiro, Brazil, from August 24 to August 29, 2014 (http://www.inmetro.gov.br/cpem2014). Experts working in the field of precision metrology and its applications to real-world situations gathered to present and discuss recent advances and open issues/questions. [ABSTRACT FROM PUBLISHER]

In the context of project management, the attention given to project portfolio management has increased in recent years. The use of mathematical programming for portfolio management is also on the rise, because it integrates the project interactions with the multiple objectives of portfolio management into a single model. Among the possible objectives, recent studies have paid special attention to the emerging objective of future preparedness, which has not yet been incorporated into the existing mathematical models. This paper presents a mixed-integer nonlinear optimization model for portfolio selection that considers four main performance measures for project management, namely, value maximization, strategic alignment, balance, and future preparedness. Given the importance of the last measure, the purpose of this paper is to provide a more complete model that provides the marginal contribution and the best combination of projects according to the needs of the company. The model is tested using real data from two companies, one in Brazil and one in Canada, and the results obtained are coherent with their respective practices. [ABSTRACT FROM AUTHOR]

Remotely sensed sea-surface temperature (SST) retrievals with a significant positive bias during the occurrence of upwelling phenomena along the southeastern coast of Brazil were reported in our companion paper. As a result, this paper proposes an automated bias correction algorithm to improve the MODIS long-wave multichannel SST (MCSST) retrievals during the abovementioned conditions in this region. In this paper, MODIS daytime SST data (SSTMODIS) and differences between brightness temperatures in MODIS channels 31 and 32 (BT31 − BT32) are analyzed simultaneously with hourly wind surface conditions, in situ SST at 0.3 and 10 m in depth (SSTbuoy03 and SSTbuoy10), and sensible and latent heat fluxes from the Cabo Frio buoy data (at 23° S, 42° W) during 2014. The obtained results show that some upwelling events present air temperature ($T_{\mathrm {air}}$) greater than SSTbuoy03 and low-atmospheric water vapor content. A simultaneous occurrence of these factors during upwelling conditions may lead to a warm-skin layer effect and may cause BT31 to be greater than SSTbuoy03 and BT31 − BT32 to be small (−0.18 °C ± 0.22 °C), affecting the MCSST performance. The proposed bias correction algorithm uses a least-squares curve between SSTbuoy03 and SSTMODIS retrievals when BT31 − BT32 ≤ 0.5 °C (i.e., dry atmospheric conditions). The bias correction algorithm has significantly improved the SSTMODIS bias (RMSE) from 1.43 °C to −0.2 °C (1.60 °C to 0.58 °C) when applied to 22 cloud-free pixels of MODIS during January–March of 2015. [ABSTRACT FROM AUTHOR]

This paper depicts an accident that happened in 2010 in a Brazilian chemical plant. A combination of different events, installations, and commissioning errors coupled with equipment failures involving the primary substation resulted in catastrophic failure. A single-phase failure of a 138-kV disconnect switch, during closing, initiated events and phenomena that resulted in a complete plant shutdown. This paper will walk the reader through the events, forensics analysis, and power system analysis that allowed the authors to identify what happened, how it happened, and what to do to prevent it from happening again. This paper will show how the anatomy of the problem, involving equipment failure, single-phase arcing, switching transients, overvoltage, capacitive coupling, transferred surge voltages, ungrounded system, transient overvoltage due to an arcing ground fault on an ungrounded system, insulation coordination, flashover, and lack of adequate surge protection, all of which resulted in a catastrophic failure of an arc resistant switchgear and a potentially serious arc flash incident. The research followed some steps that will be commented on here as well as the lessons learned. [ABSTRACT FROM AUTHOR]

The Fifth generation of mobile broadband (BB) networks, popularly known as 5G, aims to revolutionize different vertical industries, including media broadcasting. Although it remains to be seen the real impact and timescale of the 5G revolution, 5G may represent an opportunity rather than a threat for broadcast (BC), especially when considering new approaches for BC and BB evolving into new converged platforms inter-connecting terrestrial BC and cellular/wired BB systems together [item 1) in the Appendix]. Hybrid BC-BB platforms are already a success in several countries, based, e.g., on HbbTV in EU, hybridcast in Japan and Ginga in Brazil. But the increasing importance of fixed and mobile BB IP delivery for television services, well-illustrated by the new IP-based ATSC 3.0 standard [item 2) in the Appendix] and the on-going DVB-I (Internet) specification, and the fact that the 5G system will support and be interoperable with non-3GPP access technologies, potentially allowing multiple access technologies to be used simultaneously for one or more services, opens the door to new convergence scenarios. [ABSTRACT FROM AUTHOR]

This article is an extension of a work in progress paper originally presented at the conference FiE 2020, Frontiers in Education by (Schirichian et al., 2020), as a result of Schirichian’s master’s in science dissertation. It studies the relations between academic performance, protection factors, life at university, and personal characteristics to understand how they influence students’ academic success in undergraduate engineering programs in Brazil. In this challenging environment, several students overcome these issues and graduate, which indicates that some protection structures allow students to face challenging situations and be successful in their studies. Current research studied the relationships between academic performance, self-efficacy, causal attributions, personal characteristics, and life at university, with a group of 30 students. Models were studied by combining the different variables and aspects evaluated in the research, and the findings show relationship between academic performance and: 1) self-efficacy, causal attributions, and personal characteristics (such as leisure activities, living with their parents, or college accommodations) and those who attended private schools during basic education; 2 protection factors self-efficacy and causal attributions with advancing in the program and the time of enrolment in the university; and 3) the dimensions initiation and persistence, success/internality and failure/internality, indicating that those who perceive themselves as playing a major role in their academic journey tend to have better outcomes. Further results show the influence of social inequalities, particularly for those students who declared themselves brown and who conducted their basic education in public schools (which are generally of lower quality than private ones in Brazil). [ABSTRACT FROM AUTHOR]

In this paper, a simple algorithm is proposed to perform the nowcasting of rainfall in the tropical region. The algorithm applies global positioning system-derived precipitable water vapor (PWV) values and its second derivative for the short-term prediction of rainfall. The proposed algorithm incorporates the seasonal dependency of PWV values for the prediction of a rain event in the coming 5 min based on the past 30 min of PWV data. This proposed algorithm is based on the statistical study of four-year PWV and rainfall data from a station in Singapore and is validated using two-year independent data for the same station. The results show that the algorithm can achieve an average true detection rate and a false alarm rate of 87.7% and 38.6%, respectively. To analyze the applicability of the proposed algorithm, further validations are done using one-year data from one independent station from Singapore and two-year data from one station from Brazil. It is shown that the proposed algorithm performs well for both the independent stations. For the station from Brazil, the average true detection and false alarm rates are around 84.7% and 37%, respectively. All these observations suggest that the proposed algorithm is reliable and works well with a good detection rate. [ABSTRACT FROM AUTHOR]

Real-time monitoring is a key tool for several automated features in distribution system. However, due to the limited number of real-time measurements, distribution system monitoring generally relies on load modeling procedures. This paper presents field results for a real-time monitoring tool that was implemented on a Brazilian distribution utility to provide load values for service restoration software. The implemented tool comprises two steps. The first step consists of preprocessing routines that provide the required information for a real-time load estimator that is executed in the second step. The field results provide evidence of the practical viability of the implemented real-time monitoring tool, demonstrating the tool overcomes some usual limitations of real-time load estimation procedures. More specifically, the implemented tool is able to handle multiple and different types of real-time measurements, treat real-time measurements on the feeder and not only in the head of the feeder, handle obviously bad data, and to satisfy the performance requirements on practically sized distribution systems. Besides proposing and confirming a real-time monitoring tool on a real distribution system, this paper shares valuable utility experience on providing new insights and the challenges faced for real-time monitoring projects. [ABSTRACT FROM PUBLISHER]

Mine hoist systems play a vital role in gold ore transportation. They are the connection between the underground mine and the beneficiation plant. As a result, any hoist system interruption compromises the production. In this paper, it is proposed a mission critical analysis and design methodology for power converters in order to achieve proper reliability of the hoist drive system. Since the failure of power devices is responsible for a significant portion of the total downtime of power converters, a detailed study of the insulated gate bipolar transistor (IGBT) power modules lifetime is carried out. The three level neutral-point-clamped and Active Neutral Point Clamped (ANPC) IGBT-based topologies are considered for this application. The recently presented Fault-Tolerant (FT)-ANPC converter is proposed as a higher reliability solution leading to longer power modules and drive system lifetimes. All the studies are based on practical operating data from a 900-m deep shaft hoist system operating in a gold mine in southeastern Brazil. [ABSTRACT FROM AUTHOR]

This paper aims at validating a code for the evaluation of lightning-induced overvoltages developed in the PSCAD-EMTDC environment using experimental results obtained on an experimental facility deployed at the University of São Paulo, Brazil that emulates the return stroke channel with a helical antenna. For this reason, suitable expressions for the helix electromagnetic fields are presented and conditions under which they can be approximated with the ones produced by the classical lightning channel model (i.e., a vertical antenna) are derived. Moreover, the analysis of the deviations between measurements and calculations is used as a tool to propose a channel vertical coordinate dependent function for the speed that guarantees the best fitting. The validation is done considering different line configurations, from a single line to a complex layout with one main feeder and many laterals and in the presence of non-linear elements, such as surge arresters. [ABSTRACT FROM AUTHOR]

The Brazilian petroleum and chemical industry had basically used medium-voltage (MV) power assemblies based on ANSI/NEMA for many years. However, in the last three decades, due to the Brazilian Standard Association orientation, the users and manufacturers have been changing their philosophies to the IEC culture. As there has been an everyday increase in the opportunity and also in the need of MV electrical power distribution in petrochemical facilities, there is the chance of adopting an MV switchgear or controlgear design based on ANSI or IEC standards, according to each plant specifications. Although the use and design of MV assemblies are based on the electric power system needs and characteristics, they are also a result of the current scenario and experience of a specific petrochemical facility. Since both ANSI and IEC universes have strong experience, knowledge, and huge safety concerns in electrical equipment design and application, the final choice is an interesting decision. It is important to keep in mind that the use of MV assemblies has to face technical and safety key issues as they are connected to an industrial power system, and both ANSI and IEC deal with such requirements very carefully: each one in its own way. This paper deals with impacting topics related to MV switchgear and controlgear such as the following: 1) ANSI and IEC requirements; 2) rated values and characteristics; 3) ancillary and power equipment application; 4) safety; and 5) ergonomics. [ABSTRACT FROM AUTHOR]

The article talks about Institute of Electrical & Electronics Engineers ComSoc Student Chapter in Brazil founded in 2015, Aldebaro Klautau as the adviser of the chapter, hosting the seminar on signal processing for MIMO systems and on hyper-spectral image analysis. It talks about the Forum for European ICT and Media Professionals exploring the e delivery and consumption of digital media and the International conference of Computer Network held in Poland.

The time-series forecasting makes a substantial contribution in timely decision-making. In this article, a recently developed eigenvalue decomposition of Hankel matrix (EVDHM) along with the autoregressive integrated moving average (ARIMA) is applied to develop a forecasting model for nonstationary time series. The Phillips–Perron test (PPT) is used to define the nonstationarity of time series. EVDHM is applied over a time series to decompose it into respective subcomponents and reduce the nonstationarity. ARIMA-based model is designed to forecast the future values for each subcomponent. The forecast values of each subcomponent are added to get the final output values. The optimized value of ARIMA parameters for each subcomponent is obtained using a genetic algorithm (GA) for minimum values of Akaike information criterion (AIC). Model performance is evaluated by estimating the future values of daily new cases of the recent pandemic disease COVID-19 for India, USA, and Brazil. The high efficacy of the proposed method is convinced with the results. [ABSTRACT FROM AUTHOR]

The ionosphere in low-latitude regions is a major challenge for a satellite-based augmentation system (SBAS). The intense dynamics of this layer of the atmosphere in this part of the globe is one of the main reasons why Brazil discarded years ago the idea of deploying its own SBAS. In this article, we re-examine the ionospheric error bounds for a high-density ground station network in Brazil by updating previous work that assessed specific parameters for low latitudes, especially the ones related to the generation of the ionospheric error bounds expressed by the grid ionospheric vertical error (GIVE). Ionospheric delay maps and their respective GIVE values were generated by varying the functional model used in the interpolation of the grid points and the decorrelation parameter of the measurements for quiet and active days of the ionosphere. The resulting GIVE maps show values significantly higher than the bounds found in mid-latitudes and represent one of the main contributions of this article. An availability assessment for APV-I shows that the planar fit model with a spatial decorrelation standard deviation of 1 m provides the best availability for quiet days, while a quadratic fit with a decorrelation parameter of 2 m results in better availability for active days. Even though it would be possible to provide some service in quiet days within the area with a higher density of reference stations, the resulting availability is not ideal for a real SBAS when the ionosphere is more active. [ABSTRACT FROM AUTHOR]

Large-scale testing and evaluation of network solutions are complex and typically involve multiple domains (e.g., optical, wireless, and cloud). The FUTEBOL project has deployed geographically distributed testbeds in Brazil and Europe that enable the experimentation and validation of new cross-domain network solutions. In this article, we introduce a control framework that allows experimenters to slice, reserve, and orchestrate optical, wireless, and cloud resources in a coordinated manner. We illustrate the features of our control framework and evaluate it through an experiment involving resource orchestration and automatic service scaling across multiple domains. [ABSTRACT FROM AUTHOR]

A new tomographic method was developed with the main goal of mapping the ionosphere in the region of Brazil. The ionospheric background was estimated based on ionosonde and radio-occultation measurements to overcome the lack of data provided by climatological models in low-latitude regions. A new method of performing iterations of the conventional multiplicative algebraic reconstruction technique (MART) was also used in order to avoid nonilluminated cells and improve the spatial resolution. The quality assessment using independent ionosonde data during two weeks in 2013 showed a better performance of the proposed method in comparison to the international reference ionosphere, providing improvements of 31% for the F-layer peak height ${h}_{m}$ and 24% for the ionospheric peak of electron density ${N}_{m}$. The tomographic technique was also evaluated in the estimation of the total electron content (TEC) and in the single-frequency precise point positioning (PPP). Improvements of 59% in TEC and 31% in the single-frequency PPP were obtained in comparison to the results derived from global ionospheric maps. In addition, a better daily description of the ionosphere was obtained using the proposed method, where it was possible to detect the peak height increasing associated with the prereversal enhancement of the vertical plasma drift that occurs near sunset hours. The results reveal that the modified form of the MART tomographic technique can be considered a useful tool for technical and scientific communities involved in space weather, spatial geodesy, and telecommunications. [ABSTRACT FROM AUTHOR]

In Brazil, almost all fires are caused by human activities, and for very different reasons: cleaning pastures, preparation for planting, removal of excess undergrowth, hand harvesting of cane sugar, vandalism, etc. Identifying fire occurrence promptly can assist and minimize the negative impact on the affected area. This article presents an onboard fuzzy logic approach for identifying and detecting active fire spots in the Brazilian Amazon forest considering the separability of fire spectral characteristics. [ABSTRACT FROM PUBLISHER]