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

Cournot duopolies with R&D investment in the optimal reduction of production costs

Authors
Paulo, Joana Becker; Bruno M P M Oliveira; Figueiredo, Isabel M. P; Pinto, Alberto A;

Publication

Abstract

2016

Smartphones as M2M Gateways in Smart Cities IoT Applications

Authors
Pereira, C; Rodrigues, J; Pinto, A; Rocha, P; Santiago, F; Sousa, J; Aguiar, A;

Publication
2016 23RD INTERNATIONAL CONFERENCE ON TELECOMMUNICATIONS (ICT)

Abstract
Smart Cities are a key application domain for the Internet of Things (IoT), and it is coming nearer everyday through pilot trials and deployments in various cities around the world. In Porto, Portugal, a city-wide IoT Living Lab emerged after we deployed several testbeds, e.g. harbour and a city-scale vehicular networks, and carried out various experiments with the SenseMyCity crowdsensor. In this paper, we discuss how a standard Machine-to-Machine (M2M) middleware is a key enabler of our e-health platform and SenseMyCity crowdsensor, powered by the use of smartphones as M2M gateways. M2M standards provided by ETSI/oneM2M are essential for a paradigm shift, aiming at making the IoT truly interoperable without the need for human intervention. In this work, we map two applications that rely on the role of a smartphone as a gateway, which acts as a proxy to connect legacy devices to the IoT using a standard middleware. We illustrate the advantages of using M2M, and, as a proof-of-concept, we measure and quantify the energy savings obtained, showing improvements of smartphones' battery life.

2016

Six-leg single-phase to three-phase converter

Authors
de Freitas, NB; Jacobina, CB; Maia, ACN; Oliveira, AC;

Publication
2016 IEEE Energy Conversion Congress and Exposition (ECCE)

Abstract

2016

Analyzing the behavior dynamics of grain price indexes using Tucker tensor decomposition and spatio-temporal trajectories

Authors
Correa, FE; Oliveira, MDB; Gama, J; Corrêa, PLP; Rady, J;

Publication
COMPUTERS AND ELECTRONICS IN AGRICULTURE

Abstract
Agribusiness is an activity that generates huge amounts of temporal data. There are research centers that collect, store and create indexes of agricultural activities, providing multidimensional time series composed by years of data. In this paper, we are interested in studying the behavior of these time series, especially in what regards the evolution of agricultural price indexes over the years. We explore data mining techniques tailored to analyze temporal data, aiming to generate spatio-temporal trajectories of grains price indexes for six years of data. We propose the use of Tucker decomposition to both analyze the temporal patterns of these price indexes and map trajectories that represent their behavior over time in a concise and representative low-dimensional subspace. The case study presents an application of this methodology to real databases of price indexes of corn and soybeans in Brazil and the United States.

2016

A decision support method to identify target geographic markets for health care providers

Authors
Polzin, P; Borges, J; Coelho, A;

Publication
PAPERS IN REGIONAL SCIENCE

Abstract
Spatial analyses and competition assessments can be used by firms to identify target geographic markets for entry. By integrating these two kinds of analysis, this paper presents an innovative method that identifies target geographic markets for health care providers. In these target markets, supply is potentially insufficient to satisfy demand and competition problems that make entry unsuccessful are not expected to occur. Considering the Portuguese hospital health care market, an application of the method in a case study illustrates how the method works in practice.

2016

Bio-inspired Boosting for Moving Objects Segmentation

Authors
Martins, I; Carvalho, P; Corte Real, L; Luis Alba Castro, JL;

Publication
IMAGE ANALYSIS AND RECOGNITION (ICIAR 2016)

Abstract
Developing robust and universal methods for unsupervised segmentation of moving objects in video sequences has proved to be a hard and challenging task. State-of-the-art methods show good performance in a wide range of situations, but systematically fail when facing more challenging scenarios. Lately, a number of image processing modules inspired in biological models of the human visual system have been explored in different areas of application. This paper proposes a bio-inspired boosting method to address the problem of unsupervised segmentation of moving objects in video that shows the ability to overcome some of the limitations of widely used state-of-the-art methods. An exhaustive set of experiments was conducted and a detailed analysis of the results, using different metrics, revealed that this boosting is more significant when challenging scenarios are faced and state-of-the-art methods tend to fail.

  • 2438
  • 4496