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

2017

Optical Fiber Sensor for Early Warning of Corrosion of Metal Structures

Authors
Coelho, L; Santos, JL; Jorge, PAS; de Almeida, JMMM;

Publication
OCEANS 2017 - ABERDEEN

Abstract
Long period fiber gratings (LPFGs) were over coated with iron (Fe) and subjected to oxidation in air and in solutions of water containing different sodium chloride (NaCl) concentrations. The formation of iron oxides and hydroxides was monitored in real time by following the features of the gratings attenuation band. Preliminary results show that Fe coated LPFGs can be used as sensors for early warning of corrosion in offshore and in coastal projects where metal structures made of iron alloys are in contact with sea or brackish water.

2017

A Multi-Temporal Optimal Power Flow for Managing Storage and Demand Flexibility in LV Networks

Authors
Costa, HM; Sumaili, J; Madureira, AG; Gouveia, C;

Publication
2017 IEEE MANCHESTER POWERTECH

Abstract
This paper presents an algorithm developed for the optimization of Low Voltage (LV) grids that takes advantage of Distributed Energy Resources (DER) such as storage devices and flexible loads. The proposed approach is based on a multi-temporal Optimal Power Flow (OPF) algorithm that feeds from forecasting tools for load and renewable generation, which means the optimization model looks at a 24-hours horizon with hourly resolution. Specific constraints to the OPF are added to adequately model storage devices, namely their State-of-Charge (SOC) limits as well as their charging and discharging efficiencies. Moreover, a full three-phase model was built due to the unbalanced nature of LV grids motivated by the presence of single-phase load and generation. The algorithm developed has been extensively tested through simulation using a real LV Portuguese network data to illustrate the performance of the algorithm in different scenarios with good results.

2017

Regression Trees

Authors
Torgo, L;

Publication
Encyclopedia of Machine Learning and Data Mining

Abstract

2017

2D/3D Video Content Adaptation Decision Engine Based on Content Classification and User Assessment

Authors
Fernandes, R; Andrade, MT;

Publication
PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2016 (ICNAAM-2016)

Abstract
Multimedia adaptation depends on several factors, such as the content itself, the consumption device and its characteristics, the transport and access networks and the user. An adaptation decision engine, in order to provide the best possible Quality of Experience to a user, needs to have information about all variables that may influence its decision. For the aforementioned factors, we implement content classification, define device classes, consider limited bandwidth scenarios and categorize user preferences based on a subjective quality evaluation test. The results of these actions generate vital information to pass to the adaptation decision engine so that its operation may provide the indication of the most suitable adaptation to perform that delivers the best possible outcome for the user under the existing constraints.

2017

Cooperative Deep Water Seafloor Mapping with Heterogeneous Robotic Platforms

Authors
Cruz, N; Abreu, N; Almeida, J; Almeida, R; Alves, J; Dias, A; Ferreira, B; Ferreira, H; Gonçalves, C; Martins, A; Melo, J; Pinto, A; Pinto, V; Silva, A; Silva, H; Matos, A; Silva, E;

Publication
OCEANS 2017 - ANCHORAGE

Abstract
This paper describes the PISCES system, an integrated approach for fully autonomous mapping of large areas of the ocean in deep waters. A deep water AUV will use an acoustic navigation system to compute is position with bounded error. The range limitation will be overcome by a moving baseline scheme, with the acoustic sources installed in robotic surface vessels with previously combined trajectories. In order to save power, all systems will have synchronized clocks and implement the One Way Travel Time scheme. The mapping system will be a combination of an off-the-shelf MBES with a new long range bathymetry system, with a source on a moving surface vessel and the receivers on board the AUV. The system is being prepared to participate in round one of the XPRIZE challenge.

2017

Monitoring and simulation of gas pipelines through quadripole models

Authors
Baltazar, ST; Perdicoúlis, TPA; dos Santos, PL;

Publication
Lecture Notes in Electrical Engineering

Abstract
In this paper we propose to model a high pressure gas network using a quadripole approach. Although being simple, the proposed model seems to be adequate to network analysis and control, and is directly extendible to more complex networks, i.e., networks with junctions and loops. The model is proven to be liable on a case study constructed from data supplied by REN Gasodutos, where we investigate the effect of a leakage on the mass flow and pressure along the pipeline with the final objective to define a model based methodology for leakage detection and location. © Springer International Publishing Switzerland 2017.

  • 1867
  • 4138