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Publications

Publications by LIAAD

2017

Reutilization of Clinical Data for Research: The Footprint Scientific Model of the Hospital Center of Sao Joao

Authors
Guimaraes, R; Dinis Oliveira, RJ; Pereira, A; Rodrigues, P; Santos, A;

Publication
ACTA MEDICA PORTUGUESA

Abstract

2017

Combining Feature and Algorithm Hyperparameter Selection using some Metalearning Methods

Authors
Cachada, M; Abdulrahman, SM; Brazdil, P;

Publication
Proceedings of the International Workshop on Automatic Selection, Configuration and Composition of Machine Learning Algorithms co-located with the European Conference on Machine Learning & Principles and Practice of Knowledge Discovery in Databases, AutoML@PKDD/ECML 2017, Skopje, Macedonia, September 22, 2017.

Abstract
Machine learning users need methods that can help them identify algorithms or even workflows (combination of algorithms with preprocessing tasks, using or not hyperparameter configurations that are different from the defaults), that achieve the potentially best performance. Our study was oriented towards average ranking (AR), an algorithm selection method that exploits meta-data obtained on prior datasets. We focused on extending the use of a variant of AR* that takes A3R as the relevant metric (combining accuracy and run time). The extension is made at the level of diversity of the portfolio of workflows that is made available to AR. Our aim was to establish whether feature selection and different hyperparameter configurations improve the process of identifying a good solution. To evaluate our proposal we have carried out extensive experiments in a leave-one-out mode. The results show that AR* was able to select workflows that are likely to lead to good results, especially when the portfolio is diverse. We additionally performed a comparison of AR* with Auto-WEKA, running with different time budgets. Our proposed method shows some advantage over Auto-WEKA, particularly when the time budgets are small.

2017

Proceedings of the International Workshop on Automatic Selection, Configuration and Composition of Machine Learning Algorithms co-located with the European Conference on Machine Learning & Principles and Practice of Knowledge Discovery in Databases, AutoML@PKDD/ECML 2017, Skopje, Macedonia, September 22, 2017

Authors
Brazdil, P; Vanschoren, J; Hutter, F; Hoos, H;

Publication
AutoML@PKDD/ECML

Abstract

2017

Data mining techniques for the grouping of certified wines from the sub-regions of the demarcated region of Vinho Verde [Técnicas de data mining para agrupamento dos vinhos certificados das sub-regiões da região demarcada dos Vinhos Verdes]

Authors
Souza Roza, R; Brazdil, P; Reis, JL; Cerdeira, A; Martins, P; Felgueiras, O;

Publication
Atas da Conferencia da Associacao Portuguesa de Sistemas de Informacao

Abstract
The combination of information obtained from data mining technique from physicochemical and organoleptic data analysis allowed similarities between the wines of the nine sub-regions in the Demarcated Region of Vinho Verde. Through clustering techniques, four clusters were identified, each characterized by its centroid. The measure of information gain, together with supervised rule-based learning, was used to find the differentiating characteristics. This study allowed the interconnection of the characteristics of the wines of these sub-regions, which can improve the decision making on the profiles of these same wines.

2017

The Evolution of Azuma's Augmented Reality-An Overview of 20 Years of Research

Authors
Roxo, MT; Brito, PQ;

Publication
RECENT ADVANCES IN INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 2

Abstract
Augmented Reality (AR) is no longer just a gimmick. 50 years after the development of the first head-mounted display, and approaching the 20th anniversary of the first conference dedicated to AR, it is time for a new review on the theme. As such, we present a bibliometric analysis of scientific literature since 1997, using as database the Web of Science. This allowed identifying the most relevant authors, their distribution by subjects, the evolution of publishing by year and the most frequent publications.

2017

Correlates of adults' participation in sport and frequency of sport

Authors
Oliveira Brochado, A; Brito, PQ; Oliveira Brochado, F;

Publication
SCIENCE & SPORTS

Abstract
The aim of this research is to analyze the correlates of adults' participation in sport and frequency of sport. A hurdle model approach comprising a binary choice regression to model participation in sport and a count model to address frequency of sport was applied to analyze the data obtained from 516 personal interviews in a Portuguese city. Participation in sport and frequent sport are associated with men, younger people, not married and without children under 2 years, nonsmokers and regular drinkers and with good perceived health. However, participation in sport and frequency of sport participation are associated with different levels of perception of the benefits of sport activity. Whereas awareness of the health and enjoyment benefits fosters participation, fitness, socializing and appearance might increase the frequency of sport. Sport communication strategies might play a prominent role in persuading potential participants of the benefits of sport activity and frequency.

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