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Publicações

2019

Sequence and Network Mining of Touristic Routes Based on Flickr Geotagged Photos

Autores
Silva, A; Campos, P; Ferreira, C;

Publicação
PROGRESS IN ARTIFICIAL INTELLIGENCE, PT II

Abstract
Information provided by geotagged photos allow us to know where and when people have been, supporting a better understanding about tourist's movement patterns across a destination. The aim of this paper is to study tourists' movement patterns during their staying in Porto through the analysis of geotagged photos in order to fulfill marketing segmentation in an innovative way. For that purpose, the SPADE algorithm was used to find sequence patterns of tourists paths based on the time and location of the photos collected. Then, the K-Mode clustering algorithm was applied to these sequences in order to find identical behaviors in terms of paths followed by tourists. At the same time, in order to understand the influence of the different attractions on tourists' paths, we performed a Social Network Analysis of the touristic attractions (spots, museums, streets, monuments, etc.). Based on the time and location of the photos collected, along with personal information, it was possible to understand tourists' frequent movements across the city and to identify market segments based on a hybrid strategy.

2019

Optimal Sizing and Siting of Electrical Energy Storage Devices for Smart Grids Considering Time-of-Use Programs

Autores
Javadi, MS; Firuzi, K; Rezanejad, M; Lotfi, M; Gough, M; Catalao, JPS;

Publicação
45TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2019)

Abstract
This paper focuses on the long-term planning of power systems considering the impacts of Electrical Energy Storage Devices (ESSD) as well as Demand Response Programs (DRPs). The proposed model incorporates a two-stage optimization strategy in order to reduce the computational burden of the nonlinear problem. The upper-level of optimization model includes investment decision variables (long-term planning) while in the lower-level, the optimal operation of the model for short-term horizon has been addressed. In the operational stage, the optimal scheduling of power system in the presence of suggested ESSD size and location from the upper level is evaluated. Moreover, the Time-of-Use (ToU) Demand Response (DR) pricing scheme has been applied in the operational stage to evaluate its capability to reduce the total operating costs. The simulation results on the standard 6-bus test system validates the applicability of the proposed two-stage optimization model and illustrates that the optimal sizing and location of ESSDs along with DRP implementation could effectively reduce the total systems costs and improve the power system load factor.

2019

Economic-Reliability Risk-Constrained Scheduling for Resilient-Microgrids Considering Demand Response Actions

Autores
Vahedipour Dahraie, M; Rashidizadeh Kermani, H; Shafie khah, M; Lotfi, M; Catalao, JPS;

Publicação
45TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2019)

Abstract
In this paper, a risk-constrained optimal scheduling framework is proposed for an economic and reliable operation of microgrids. The framework is developed based on a scenario-based optimization technique, to schedule the microgrid operation both in normal and islanding modes. The prevailing uncertainties of islanding duration as well as prediction errors of loads, market prices and renewable power generation are addressed in the scheduling problem. The effect of participation of customers in demand response (DR) programs is investigated on economic-reliable operating solutions. Also, the uncertainties associated with wind power, loads and electricity prices as well as the uncertainties of islanding duration events of the microgrid are modeled, properly. The optimal scheduling carried out through a unit commitment algorithm and an AC power flow procedure by considering system's objectives and constraints. Moreover, to adequately handle the uncertainties of the problem, conditional value-at-risk (CVaR) metric is incorporated into the optimization model to evaluate the profit risk associated with operator's decisions in different conditions. With the proposed model, the impacts of DR actions, in terms of economy and reliability, are investigated with a 400 V microgrid system.

2019

Automatic Identification of Economic Activities in Complaints

Autores
Barbosa, L; Filgueiras, J; Rocha, G; Cardoso, HL; Reis, LP; Machado, JP; Caldeira, AC; Oliveira, AM;

Publicação
Statistical Language and Speech Processing - 7th International Conference, SLSP 2019, Ljubljana, Slovenia, October 14-16, 2019, Proceedings

Abstract
In recent years, public institutions have undergone a progressive modernization process, bringing several administrative services to be provided electronically. Some institutions are responsible for analyzing citizen complaints, which come in huge numbers and are mainly provided in free-form text, demanding for some automatic way to process them, at least to some extent. In this work, we focus on the task of automatically identifying economic activities in complaints submitted to the Portuguese Economic and Food Safety Authority (ASAE), employing natural language processing (NLP) and machine learning (ML) techniques for Portuguese, which is a language with few resources. We formulate the task as several multi-class classification problems, taking into account the economic activity taxonomy used by ASAE. We employ features at the lexical, syntactic and semantic level using different ML algorithms. We report the results obtained to address this task and present a detailed analysis of the features that impact the performance of the system. Our best setting obtains an accuracy of 0.8164 using SVM. When looking at the three most probable classes according to the classifier’s prediction, we report an accuracy of 0.9474. © 2019, Springer Nature Switzerland AG.

2019

Learning Entrepreneurship in Higher Education Through Flow Theory and FLIGBY Game

Autores
Almeida, F; Buzády, Z;

Publicação
Int. J. Virtual Pers. Learn. Environ.

Abstract
This article performs an exploratory study of the potential of flow theory and FLIGBY game to contribute to develop entrepreneurship competencies among higher education students. For this purpose, this study considers the use of a focus group consisting of eight students enrolled in the entrepreneurship course in a higher educational institution in Portugal, in which students for two months explored FLIGBY. The results obtained allowed us to conclude that FLIGBY was also suitable to be explored in the context of entrepreneurship classes. Students emphasized the potential of the game to be applied for training of management skills, the recognition of their leadership skills, and the exploration of new approaches to the management challenges. Finally, it should be noted that the benefits offered by FLIGBY were experienced differently by students with professional experience in IT and management fields. Those students emphasized the application of the game to the real world and the potential offered for FLIGBY for allowing students to explore new skills and actions.

2019

Assisting Health Consumers While Searching the Web Through Medical Annotations

Autores
Lopes, CT; Sousa, H;

Publicação
PROCEEDINGS OF THE 2019 CONFERENCE ON HUMAN INFORMATION INTERACTION AND RETRIEVAL (CHIIR'19)

Abstract
Health consumers usually face difficulties on their online searches, mainly because of the differences between terminologies used by laypeople and health professionals. This work presents a tool, HealthTranslator, available as a Google Chrome extension that intends to reduce this terminological gap while users are searching the Web for health information. HealthTranslator automatically annotates medical concepts in web documents, providing additional information, such as concept definition, related concepts and links to external references. The solution was evaluated regarding its: ( a) performance-the document processing is done gradually, typically from the top to the bottom of the document and performance was not an issue raised by the users; ( b) concept coverage-the solution was compared to a similar extension performing in English recognizing significantly more concepts. A comparison with a corpus of Portuguese documents manually annotated with medical concepts showed an average F-measure between 27% and 33%, depending on the type of concepts being recognized; ( c) users' receptivity to HealthTranslator and its usability-many aspects were surveyed on a user study. In general, the extension has a good acceptance and users find it useful.

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