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

2016

A Methodology for the Evaluation and Deployment of Wireless Multi-hop Networks in Smart Grids

Authors
Rua, D; Ribeiro, F; Campos, R; Ruela, J; Pecas Lopes, JAP;

Publication
2016 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)

Abstract
Smart grids aim at ensuring a secure, reliable and efficient operation of power systems and for that purpose they need communications infrastructures capable of meeting different requirements. Current and emerging wireless multi-hop solutions based on standard technologies are strong candidates for communications networks associated and integrated with electric distribution grids but a suitable methodology to evaluate and deploy them is missing. This paper presents a holistic methodology supported by contextual information used to generate different scenarios of distribution grids and to evaluate and deploy wireless communications networks for smart grids. Simulation results show that the methodology is suitable for the evaluation of wireless multi-hop networks in the smart grid context and prove that the performance of such networks meets the expected requirements of different applications.

2016

Breast Conserving Surgery Outcome Prediction: A Patient-Specific, Integrated Multi-modal Imaging and Mechano-Biological Modelling Framework

Authors
Eiben, B; Lacher, R; Vavourakis, V; Hipwell, JH; Stoyanov, D; Williams, NR; Sabczynski, J; Bülow, T; Kutra, D; Meetz, K; Young, S; Barschdorf, H; Oliveira, HP; Cardoso, JS; Monteiro, JP; Zolfagharnasab, H; Sinkus, R; Gouveia, P; Liefers, GJ; Molenkamp, B; van de Velde, CJH; Hawkes, DJ; Cardoso, MJ; Keshtgar, M;

Publication
BREAST IMAGING, IWDM 2016

Abstract
Patient-specific surgical predictions of Breast Conserving Therapy, through mechano-biological simulations, could inform the shared decision making process between clinicians and patients by enabling the impact of different surgical options to be visualised. We present an overview of our processing workflow that integrates MR images and three dimensional optical surface scans into a personalised model. Utilising an interactively generated surgical plan, a multi-scale open source finite element solver is employed to simulate breast deformity based on interrelated physiological and biomechanical processes that occur post surgery. Our outcome predictions, based on the pre-surgical imaging, were validated by comparing the simulated outcome with follow-up surface scans of four patients acquired 6 to 12 months post-surgery. A mean absolute surface distance of 3.3mm between the follow-up scan and the simulation was obtained.

2016

Development of a flexible language for disturbance description for multi-robot missions

Authors
Silva, DC; Abreu, PH; Reis, LP; Oliveira, E;

Publication
JOURNAL OF SIMULATION

Abstract
This paper introduces the Disturbance Description Language (DDL), an XML dialect intended to describe a number of anomalous elements that can occur in a given scenario (including people, vehicles, fire or focus of pollution) and their respective properties, such as temporal availability, location, motion pattern and details for individual components, such as growth pattern and detectability. This dialect is part of a framework to support the execution of cooperative missions by a group of vehicles, in a simulated, augmented or real environment. An interface was incorporated into the framework, for creating and editing XML files following the defined schema. Once the information is correctly specified, it can be used in the framework, thus facilitating the process of environment disturbances specification and deployment. A survey answered by both practitioners and researchers shows that the degree of satisfaction with DDL is elevated (the overall evaluation of DDL achieved a 4.14 score (out of 5), with 81.1% of the answers being equal to or above 4); also, the usability of the interface was evaluated, having achieved a score of 83.6 in the SUS scale. These results imply that DDL is flexible enough to represent several types of disturbances, through a user-friendly interface.

2016

Value Analysis approach in the resources pre-selection of agile/virtual enterprises: Domain of applicability and selection time

Authors
Pires A.; Ávila P.; Putnik G.;

Publication
Proceedings of 2015 International Conference on Industrial Engineering and Systems Management, IEEE IESM 2015

Abstract
For the project of an Agile/Virtual Enterprise (A/V E) the resources selection is a key factor. The resources systems (output of the selection process) should be prepared to guarantee quality, efficiency and cost-attractiveness, in order to ensure the agility and integrability of the A/V E. This is a difficult matter because it can be a combinatorial and multi-criteria problem. Despite the potential of Value Analysis (VA), none of the resources selection models found in the literature incorporates the evaluation of the resources value. They approach mainly the factors cost and/or time. So, our model constitutes an innovative approach because it gives the highest importance to the value of the resources systems, through the incorporation of VA. The main objective is to quantify the selection process performance with VA integrated into the pre-selection of resources in accordance with the developed model. The paper contribution is the positive confirmation, through the simulation results analysis, of the benefits of VA integration in the resources selection process: greater applicability domain for candidate resources and number of tasks; and reduction of the selection time. In conclusion, the increased efficiency and the superior applicability domain of the model are demonstrated.

2016

Support Vector Machines for decision support in electricity markets' strategic bidding

Authors
Pinto, T; Sousa, TM; Praça, I; Vale, Z; Morais, H;

Publication
NEUROCOMPUTING

Abstract
Energy systems worldwide are complex and challenging environments. Multi-agent based simulation platforms are increasing at a high rate, as they show to be a good option to study many issues related to these systems, as well as the involved players at act in this domain. In this scope the authors' research group has developed a multi-agent system: Multi-Agent System for Competitive Electricity Markets (MASCEM), which simulates the electricity markets environment. MASCEM is integrated with Adaptive Learning Strategic Bidding System (ALBidS) that works as a decision support system for market players. The ALBidS system allows MASCEM market negotiating players to take the best possible advantages from the market context. This paper presents the application of a Support Vector Machines (SVM) based approach to provide decision support to electricity market players. This strategy is tested and validated by being included in ALBidS and then compared with the application of an Artificial Neural Network (ANN), originating promising results: an effective electricity market price forecast in a fast execution time. The proposed approach is tested and validated using real electricity markets data from MIBEL - Iberian market operator.

2016

Exploring a Large News Collection Using Visualization Tools

Authors
Devezas, T; Devezas, JL; Nunes, S;

Publication
NewsIR@ECIR

Abstract
The overwhelming amount of news content published online every day has made it increasingly difficult to perform macro-level analysis of the news landscape. Visual exploration tools harness both computing power and human perception to assist in making sense of large data collections. In this paper, we employed three visualization tools to explore a dataset comprising one million articles published by news organizations and blogs. The visual analysis of the dataset revealed that 1) news and blog sources evaluate very differently the importance of similar events, granting them distinct amounts of coverage, 2) there are both dissimilarities and overlaps in the publication patterns of the two source types, and 3) the content's direction and diversity behave differently over time.

  • 2599
  • 4503