2017
Autores
Tavares, J; Mamede, HS; Amaral, P; Pinto, P;
Publicação
2017 12TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)
Abstract
The number of software-defined controllers available in the market has increased greatly in the last few years. Nowadays, it is possible to find proprietary controllers as well as open source controllers. Examples are companies as HPE and Cisco that offer those two types of controllers to their clients simultaneously. It is also important to note that in both, the open source version is a commercial distribution of OpenDaylight. In the current market it is possible to find controllers for different areas of deployment, with a different programming language and supporting different southbound protocols. Therefore, we considered worth providing a description and a comparison of the main existing controllers.
2017
Autores
Mendes, VB; Barbosa, SM; Romero, I; Madeira, J; da Silveira, AB;
Publicação
GEOPHYSICAL JOURNAL INTERNATIONAL
Abstract
This study addresses long-term sea level variability in Macaronesia from a holistic perspective using all available instrumental records in the region, including a dense network of GPS continuous stations, tide gauges and satellite observations. A detailed assessment of vertical movement from GPS time series underlines the influence of the complex volcano-tectonic setting of the Macaronesian islands in local uplift/subsidence. Relative sea level for the region is spatially highly variable, ranging from -1.1 to 5.1 mm yr(-1). Absolute sea level from satellite altimetry exhibits consistent trends in the Macaronesia, with a mean value of 3.0 +/- 0.5 mm yr(-1). Typically, sea level trends from tide gauge records corrected for vertical movement using the estimates from GPS time series are lower than uncorrected estimates. The agreement between satellite altimetry and tide gauge trends corrected for vertical land varies substantially from island to island. Trends derived from the combination of GPS and tide gauge observations differ by less than 1 mm yr(-1) with respect to absolute sea level trends from satellite altimetry for 56 per cent of the stations, despite the heterogeneity in length of both GPS and tide gauge series, and the influence of volcanic-tectonic processes affecting the position of some GPS stations.
2017
Autores
Barbosa, SM; Miranda, P; Azevedo, EB;
Publicação
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY
Abstract
This work addresses the short-term variability of gamma radiation measured continuously at the Eastern North Atlantic (ENA) facility located in the Graciosa island (Azores, 39N; 28W), a fixed site of the Atmospheric Radiation Measurement programme (ARM). The temporal variability of gamma radiation is characterized by occasional anomalies over a slowly-varying signal. Sharp peaks lasting typically 2-4 h are coincident with heavy precipitation and result from the scavenging effect of precipitation bringing radon progeny from the upper levels to the ground surface. However the connection between gamma variability and precipitation is not straightforward as a result of the complex interplay of factors such as the precipitation intensity, the PBL height, the cloud's base height and thickness, or the air mass origin and atmospheric concentration of sub-micron aerosols, which influence the scavenging processes and therefore the concentration of radon progeny. Convective precipitation associated with cumuliform clouds forming under conditions of warming of the ground relative to the air does not produce enhancements in gamma radiation, since the drop growing process is dominated by the fast accretion of liquid water, resulting in the reduction of the concentration of radionuclides by dilution. Events of convective precipitation further contribute to a reduction in gamma counts by inhibiting radon release from the soil surface and by attenuating gamma rays from all gamma-emitting elements on the ground. Anomalies occurring in the absence of precipitation are found to be associated with a diurnal cycle of maximum gamma counts before sunrise decreasing to a minimum in the evening, which are observed in conditions of thermal stability and very weak winds enabling the build-up of near surface radon progeny during the night.
2017
Autores
Yan, WL; Bastos, L; Madeira, S; Magalhaes, A; Goncalves, JA;
Publicação
PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING
Abstract
A simple and inexpensive POS for application to light airborne platforms was developed, and a modified Kalman Filtering was designed to integrate GNSS/IMU/Image data, which uses the relative orientation information to improve the accuracy of the exterior orientation parameters. The precise relative orientation of conjugate images was obtained using a SIFT/SFM matching algorithm. The relative exterior orientations were transformed from the camera frame to the navigation frame before they were used as external update information of the Kalman Filter. Combining all the relative orientation information retrieved from images, the Kalman Filter can give an improved output for the exterior orientation parameters. Airborne result from the tests of one straight strip shows that the heading accuracy of a GNSS/MEMS-IMU was improved from 0.26 degrees to 0.10 degrees, and the result from one closed strip shows that heading accuracy was improved from 1.11 degrees to 0.85 degrees and roll accuracy from 0.54 degrees to 0.43 degrees.
2017
Autores
Rocha, T; University of Trás-os-Montes e Alto Douro and INESC TEC, PORTUGAL,; Martins, J; Branco, F; Gonçalves, R; University of Trás-os-Montes e Alto Douro and INESC TEC, PORTUGAL,; University of Trás-os-Montes e Alto Douro and INESC TEC, PORTUGAL,; University of Trás-os-Montes e Alto Douro and INESC TEC, PORTUGAL,;
Publicação
Journal of Information Systems Engineering & Management
Abstract
2017
Autores
Au Yong oliveira, M; Moreira, F; Branco, F; Martins, J; Gonçalves, R;
Publicação
Proceedings of the European Conference on Innovation and Entrepreneurship, ECIE
Abstract
While lecturers who gave their testimonials to us admit that workloads in academia are extremely high they still accept to direct study cycles without receiving extra pay or any apparent benefits, besides added status and prestige. Similarly, students surveyed (n=69) also want to do socially responsible activity when they become executives, even though this may go against their evaluation (as profit maximizers) by shareholders. Is society and academia in particular becoming more altruistic? One might say that social responsibility is no longer an option, that informed consumers are looking to buy from socially responsible enterprises. One might also assume that in academia, which is a very hierarchical environment, that individuals initiating careers in academia are not in a position to decline invitations to coordinate study cycles. We do also, however, with our study, see evidence of something beyond the above more authoritarian reasons for wanting to do good in society. Individuals may genuinely want to contribute as more basic needs are increasingly fulfilled and individuals seek a higher and more worthwhile purpose in life. When asked whether social responsibility is a question of marketing, a number of students were divided on this issue. Just under one third answered neutrally, and over half answered neutral or disagreeing. The sample of students is interested in social responsibility - with over three quarters revealing a strong connection with social responsibility activity. Firms should not only seek profit, our students stated in majority, though seeking a profit is not seen by the majority to be a sign of being wicked. Previous studies on human motivation have emphasized how, in more advanced societies, needs follow a hierarchy and at the highest level one will find worthwhile accomplishment. What is novel is that this worthwhile accomplishment is not linked to material success but to wanting to do good in society. Further in-depth research is necessary into such change in society, towards a softer stance than that advocated by Milton Friedman in the 1970s, in his landmark paper defending that profit is the social responsibility of firms and that executives know nothing about solving the poverty problem or unemployment or inflation and so should stay away from seeking to solve these problems (rather, leave that to civil servants). We have found that change is upon us and that millennials want to play an active role in solving society's woes, so more research in this area is necessary to quantify the change and its effects.
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