Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by HumanISE

2017

Enabling Distributed SME

Authors
Trovao, H; Mamede, HS; da Silva, MM;

Publication
2017 12TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)

Abstract
In some industries, recruiting qualified resources can be a problem for SMEs, one option is to start a transformation process, and move from a traditional team to a distributed team, gaining access to a much larger base of possible human resources and business opportunities. Digital transformation can be used to help SMEs in taking the steps needed to become distributed companies. This paper shows how applying a lightweight TOGAF-based methodology to an ongoing digital transformation process, specifically targeting a SME information system, can create opportunities for the company.

2017

Software-Defined Controllers: Where are we?

Authors
Tavares, J; Mamede, HS; Amaral, P; Pinto, P;

Publication
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

Vertical land motion and sea level change in Macaronesia

Authors
Mendes, VB; Barbosa, SM; Romero, I; Madeira, J; da Silveira, AB;

Publication
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

Short-term variability of gamma radiation at the ARM Eastern North Atlantic facility (Azores)

Authors
Barbosa, SM; Miranda, P; Azevedo, EB;

Publication
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

Using Relative Orientation to Improve the Accuracy of Exterior Orientation Parameters of Low Cost POS

Authors
Yan, WL; Bastos, L; Madeira, S; Magalhaes, A; Goncalves, JA;

Publication
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

Evaluating Youtube Platform Usability by People with Intellectual Disabilities (A User Experience Case Study Performed in a Six-Month Period)

Authors
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,;

Publication
Journal of Information Systems Engineering & Management

Abstract

  • 290
  • 589