2017
Authors
Vinagre, E; Pinto, T; Ramos, S; Vale, Z; Corchado, JM;
Publication
Proceedings - International Workshop on Database and Expert Systems Applications, DEXA
Abstract
Smart Grid (SG) concept is defined as an electricity network operated intelligently to integrate the behavior and actions of all energy resources connected to the network to ensure efficient, sustainable, economic and secure supply of electricity. This concept emerged in recent decades not only for economic reasons but also ecological and even political. SG have been the subject of major studies and investments and continues to represent an area of enormous challenges. Some of the problems of intelligent systems connected to the managed SG are: the real-time processing optimization algorithms and demand response programs; and more accurate predictions in the management of production and consumption. This paper presents a case study for evaluating the performance and accuracy of energy consumption forecast with use of SVM (Support Vector Machines) in different frameworks. © 2016 IEEE.
2017
Authors
Areias, M; Rocha, R;
Publication
JOURNAL OF SYSTEMS AND SOFTWARE
Abstract
Tabling is a powerful implementation technique that improves the declarativeness and expressiveness of traditional Prolog systems in dealing with recursion and redundant computations. It can be viewed as a natural tool to implement dynamic programming problems, where a general recursive strategy divides a problem in simple sub-problems that are often the same. When tabling is combined with multithreading, we have the best of both worlds, since we can exploit the combination of higher declarative semantics with higher procedural control. However, at the engine level, such combination for dynamic programming problems is very difficult to exploit in order to achieve execution scalability as we increase the number of running threads. In this work, we focus on two well-known dynamic programming problems, the Knapsack and the Longest Common Subsequence problems, and we discuss how we were able to scale their execution by using the multithreaded tabling engine of the Yap Prolog system. To the best of our knowledge, this is the first work showing a Prolog system to be able to scale the execution of multithreaded dynamic programming problems. Our experiments also show that our system can achieve comparable or even better speedup results than other parallel implementations of the same problems.
2017
Authors
Mendonca, AM; Remeseiro, B; Dashtbozorg, B; Campilho, A;
Publication
MEDICAL IMAGING 2017: COMPUTER-AIDED DIAGNOSIS
Abstract
The Arteriolar-to-Venular Ratio (AVR) is a popular dimensionless measure which allows the assessment of patients' condition for the early diagnosis of different diseases, including hypertension and diabetic retinopathy. This paper presents two new approaches for AVR computation in retinal photographs which include a sequence of automated processing steps: vessel segmentation, caliber measurement, optic disc segmentation, artery/vein classification, region of interest delineation, and AVR calculation. Both approaches have been tested on the INSPIRE-AVR dataset, and compared with a ground-truth provided by two medical specialists. The obtained results demonstrate the reliability of the fully automatic approach which provides AVR ratios very similar to at least one of the observers. Furthermore, the semi-automatic approach, which includes the manual modification of the artery/vein classification if needed, allows to significantly reduce the error to a level below the human error.
2017
Authors
Oliveira, E; Gama, J; Vale, Z; Lopes Cardoso, H;
Publication
Lecture Notes in Computer Science
Abstract
2017
Authors
Nagarajan, R; Teixeira, AAC; Silva, S;
Publication
SINGAPORE ECONOMIC REVIEW
Abstract
Population ageing and its influence on the economic growth has long been the focus of major concern. Using bibliometric techniques we found that: (1) although ageing has increasingly attracted more researchers within economics literature, the relative weight of ageing and economic growth related papers does not evidence a clear positive trend; (2) recent studies reveal the willingness of researchers to evaluate less immediate mechanisms relating ageing and economic growth; (3) the increase in the use of empirical methods reflects a trend to test economic phenomena with real-world data against the theory; (4) very few studies focus on developing and less developed countries.
2017
Authors
Cruz, R; Fernandes, K; Costa, JFP; Cardoso, JS;
Publication
ADVANCES IN COMPUTATIONAL INTELLIGENCE, IWANN 2017, PT II
Abstract
In many applications, false positives (type I error) and false negatives (type II) have different impact. In medicine, it is not considered as bad to falsely diagnosticate someone healthy as sick (false positive) as it is to diagnosticate someone sick as healthy (false negative). But we are also willing to accept some rate of false negatives errors in order to make the classification task possible at all. Where the line is drawn is subjective and prone to controversy. Usually, this compromise is given by a cost matrix where an exchange rate between errors is defined. For many reasons, however, it might not be natural to think of this trade-off in terms of relative costs. We explore novel learning paradigms where this trade-off can be given in the form of the amount of false negatives we are willing to tolerate. The classifier then tries to minimize false positives while keeping false negatives within the acceptable bound. Here we consider classifiers based on kernel density estimation, gradient descent modifications and applying a threshold to classifying and ranking scores.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.