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Publications

2015

SPECIAL ISSUE: Sustaining Resilience in Today's Demanding Environments

Authors
Azevedo, A; Almeida, A;

Publication
ROBOTICS AND COMPUTER-INTEGRATED MANUFACTURING

Abstract

2015

A New Methodology for Solving the Unit Commitment in Insular Grids Including Uncertainty of Renewable Energies

Authors
Osorio, GJ; Lujano Rojas, JM; Matias, JCO; Catalao, JPS;

Publication
2015 IEEE 5TH INTERNATIONAL CONFERENCE ON POWER ENGINEERING, ENERGY AND ELECTRICAL DRIVES (POWERENG)

Abstract
Due to increasing integration of renewable generation into the electrical framework in last decades, the mathematical techniques required for the optimal day-ahead scheduling needs to be continuously improved, specifically for modeling the variability of these sources. In this paper, a method for producing a new solution for the stochastic unit commitment (UC) problem from the analysis of each scenario is developed. The methodology described in this paper can deal with a large number of scenario sets with a reasonable computational effort, by finding the common and feasible solutions for the scenario set under analysis.

2015

User Modelling in Scheduling System with Artificial Neural Networks

Authors
Cunha, B; Madureira, A; Pereira, JP;

Publication
PROCEEDINGS OF THE 2015 10TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI 2015)

Abstract
User modelling has become a central subject for anybody interested in understanding how users interact with technology. Personalization is a key issue in an era when there is so much information and so many people interacting in so many ways. Modern users desire a customized experience that adapts itself to their requirements and understands what they need even before they notice it. In order to morph any system into an adapting one, every relevant interaction with its users has to be maintained. Then, a mathematical structure capable of discovering patterns amongst that information is necessary, being able to classify users according to the roles they play. With a correct user categorization, the system knows when, how and what to do to adapt its content, via a mixed-initiative approach. In this paper, an artificial neural network is selected as classifier and users are divided in three roles, from beginners to experts. ADSyS, the target system of this proposal, adapts its content based on who is operating it, providing a higher usability. This guide on how to adapt a system to its users is built as part of ADSyS, but is intended to be generalized as a foundation to other systems.

2015

Monitoring of landslide activity in Slovakia territory using multi-temporal insar techniques

Authors
Bakon, M; Papco, J; Perissin, D; Lazecky, M; Sousa, JJ; Hlavacova, I; Batorova, K; Ondrejka, P; Liscak, P; Paudits, P; Real, N;

Publication
European Space Agency, (Special Publication) ESA SP

Abstract
Slope deformations are the most important geohazards in Slovakia which annually cause an extensive economic damage of significant influence. About 22000 slope deformations have been registered so far, covering an area of almost 2600 km2. Since 2010, 639 new slope failures have been witnessed and their activation was driven mainly by the climatic anomalies such as extraordinary rainfalls. Many of these landslides currently represent a direct threat to the lives, health and property of the residents in the affected areas. The landslide Nizna Mysla is considered to be the second most catastrophic landslide in the history of Slovakia. Damages to buildings and engineering networks had not been identified in the'90s of the last century when the first problems with the slope stability appeared. Up-tonow monitoring techniques has currently been reassessed to account for the results from satellite Synthetic Aperture Radar (SAR) techniques.

2015

Six thinking hats: A novel metalearner for intelligent decision support in electricity markets

Authors
Pinto, T; Barreto, J; Praca, I; Sousa, TM; Vale, Z; Pires, EJS;

Publication
DECISION SUPPORT SYSTEMS

Abstract
The energy sector has suffered a significant restructuring that has increased the complexity in electricity market players' interactions. The complexity that these changes brought requires the creation of decision support tools to facilitate the study and understanding of these markets. The Multiagent Simulator of Competitive Electricity Markets (MASCEM) arose in this context, providing a simulation framework for deregulated electricity markets. The Adaptive Learning strategic Bidding System (ALBidS) is a multiagent system created to provide decision support to market negotiating players. Fully integrated with MASCEM, ALBidS considers several different strategic methodologies based on highly distinct approaches. Six Thinking Hats (STH) is a powerful technique used to look at decisions from different perspectives, forcing the thinker to move outside its usual way of thinking. This paper aims to complement the ALBidS strategies by combining them and taking advantage of their different perspectives through the use of the STH group decision technique. The combination of ALBidS' strategies is performed through the application of a genetic algorithm, resulting in an evolutionary learning approach.

2015

Exactly-Once Quantity Transfer

Authors
Shoker, A; Almeida, PS; Baquero, C;

Publication
2015 IEEE 34th Symposium on Reliable Distributed Systems Workshop (SRDSW)

Abstract
Strongly consistent systems supporting distributed transactions can be prone to high latency and do not tolerate partitions. The present trend of using weaker forms of consistency, to achieve high availability, poses notable challenges in writing applications due to the lack of linearizability, e.g., to ensure global invariants, or perform mutator operations on a distributed datatype. This paper addresses a specific problem: the exactly-once transfer of a "quantity" from one node to another on an unreliable network (coping with message duplication, loss, or reordering) and without any form of global synchronization. This allows preserving a global property (the sum of quantities remains unchanged) without requiring global linearizability and only through using pairwise interactions between nodes, therefore allowing partitions in the system. We present the novel quantity-transfer algorithm while focusing on a specific use-case: a redistribution protocol to keep the quantities in a set of nodes balanced; in particular, averaging a shared real number across nodes. Since this is a work in progress, we briefly discuss the correctness of the protocol, and we leave potential extensions and empirical evaluations for future work.

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