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Publicações

2019

Hybrid Forecasting Model for Short-Term Electricity Market Prices with Renewable Integration

Autores
Osorio, GJ; Lotfi, M; Shafie khah, M; Campos, VMA; Catalao, JPS;

Publicação
SUSTAINABILITY

Abstract
In recent years, there have been notable commitments and obligations by the electricity sector for more sustainable generation and delivery processes to reduce the environmental footprint. However, there is still a long way to go to achieve necessary sustainability goals while ensuring standards of robustness and the quality of power grids. One of the main challenges hindering this progress are uncertainties and stochasticity associated with the electricity sector and especially renewable generation. In this paradigm shift, forecasting tools are indispensable, and their utilization can significantly improve system operation and minimize costs associated with all related activities. Thus, forecasting tools have an essential key role in all decision-making stages. In this work, a hybrid probabilistic forecasting model (HPFM) was developed for short-term electricity market prices (EMP) combining wavelet transforms (WT), hybrid particle swarm optimization (DEEPSO), adaptive neuro-fuzzy inference system (ANFIS), and Monte Carlo simulation (MCS). The proposed hybrid probabilistic forecasting model (HPFM) was tested and validated with real data from the Spanish and Pennsylvania-New Jersey-Maryland (PJM) markets. The proposed model exhibited favorable results and performance in comparison with previously published work considering electricity market prices (EMP) data, which is notable.

2019

The Impact of Gender, Avatar and Height in Distance Perception in Virtual Environments

Autores
Coelho, H; Melo, M; Branco, F; Raposo, JV; Bessa, M;

Publicação
New Knowledge in Information Systems and Technologies - Volume 2, World Conference on Information Systems and Technologies, WorldCIST 2019, Galicia, Spain, 16-19 April

Abstract
Virtual Reality is becoming more popular over the years because it allows the user to be the main actor in another environment and interact with it in real time. New interaction methods are being studied, like tangible interfaces, but there is little work done related to small distances when grabbing objects through a virtual environment. This study is important because, in our perspective, interaction in virtual reality will be at arms reach, meaning that the user will interact within very close distances (under 1 m). In this paper, the research team further evaluate distance perception using gender, the presence of avatar and height (fixed or personalised). The sample consisted of 64 participants (32 females and 32 males) evenly distributed between all four conditions (8 males and 8 females for each condition). Results revealed that gender does have an impact on small distance estimation; height does not have an impact on distance estimation; and avatar does make a difference when trying to grab a real object through the virtual environment. © Springer Nature Switzerland AG 2019.

2019

Optimal design of additive manufacturing supply chains

Autores
Basto, J; Ferreira, JS; Alcalá, SGS; Frazzon, E; Moniz, S;

Publicação
Proceedings of the International Conference on Industrial Engineering and Operations Management

Abstract
Additive Manufacturing (AM) is one of the most trending production technologies, with a growing number of companies looking forward to implementing it in their processes. Producing through AM not only means that there are no supplier lead times needed to account for, but also enables production closer to the end customer, reducing then the delivery time. This is especially true for companies with a wide range of low and variable demand products. This paper proposes a mixed integer linear programming (MILP) model for the optimal design of supply chains facing the introduction of AM processes. In the addressed problem, the 3D printers allocation to distribution centers (DC), that will make or customize parts, and the Suppliers-DC-Customers connections for each product need to be defined. The model aims at minimizing the supply chain costs, exploring the trade-offs between safety stock and stockout costs, and between buying and 3D printing a part. The main relevant characteristics of this model are the introduction of stock service levels as decision variables and the use of a linearization of the cumulative distribution function to account for demand uncertainty. A real-world problem from a maintenance provider is solved, showing the applicability of the model. © 2019, IEOM Society International.

2019

A clinical risk matrix for obstructive sleep apnea using Bayesian network approaches

Autores
Santos, DF; Rodrigues, PP;

Publicação
Int. J. Data Sci. Anal.

Abstract
In obstructive sleep apnea, respiratory effort is maintained but ventilation decreases/disappears due to upper-airway partial/total occlusion. This condition affects about 4% of men and 2% of women worldwide. This study aimed to define an auxiliary diagnostic method that can support the decision to perform polysomnography, based on risk and diagnostic factors. Our sample performed polysomnography between January and May 2015. Two Bayesian classifiers were used to build the models: Naïve Bayes and Tree Augmented Naïve Bayes, using 38 variables identified by literature review or just a selection of 6. Area under the ROC curve, sensitivity, specificity and predictive values were evaluated using leave-one-out and cross-validation techniques. From a total of 241 patients, only 194 fulfilled the inclusion criteria, 123 (63%) were male, with a mean age of 58 years, 66 (34%) patients had a normal result and 128 (66%) a diagnosis of obstructive sleep apnea. The cross-validated AUCs for each model were: NB38: 69.2%; TAN38: 69.0%; NB6: 74.6% and TAN6: 63.6%. Regarding risk matrix, female gender presented a starting rate of 8%, comparing to 20% in male gender, almost 3 times higher. The high (34%) proportion of normal results confirms the need for a pre-evaluation prior to polysomnography, making the search for a validated model to screen patients with suspicion of obstructive sleep apnea essential, especially at primary care level.

2019

ROSM - Robotic Oil Spill Mitigation

Autores
Dias, A; Mucha, AP; Santos, T; Pedrosa, D; Amaral, G; Ferreira, H; Oliveira, A; Martins, A; Almeida, J; Almeida, CM; Ramos, S; Magalhaes, C; Carvalho, MF; Silva, E;

Publicação
OCEANS 2019 - MARSEILLE

Abstract
The overall aim of the ROSM project is the implementation of an innovative solution based on heterogeneous autonomous vehicles to tackle maritime pollution (in particular, oil spills). These solutions will be based on native microbial consortia with bioremediation capacity, and the adaptation of air and surface autonomous vehicles for in-situ release of autochthonous microorganisms (bioaugmentation) and nutrients (biostimulation). By doing so, these systems can be used as the first line of the responder to pollution incidents from several origins that may occur inside ports, around industrial and extraction facilities, or during transport activities, in a fast, efficient and low-cost way. The paper will address the development of a team of autonomous vehicles able to carry, as payload, native organisms to naturally degrade oil spills (avoiding the introduction of additional chemical or biological additives), the development of a multi-robot system able to provide a first line responses to oil spill incidents under unfavourable and harsh conditions with low human intervention, and then a decentralized cooperative planning with the ability to coordinate an efficient oil spill combat. Field tests have been performed in Leixoes Harbour in Porto and Medas, Portugal, with a simulated oil spill and validated the decentralized coordinated task between the autonomous surface vehicle (ASV) ROAZ and the unmanned aerial vehicle (UAV).

2019

The Role of Information and Communication Technologies in the Creation and Support of Touristic Routes

Autores
Carvalho, A; Cunha, CR; Mendonca, V; Morais, EP;

Publicação
EDUCATION EXCELLENCE AND INNOVATION MANAGEMENT THROUGH VISION 2020

Abstract
The tourism sector has become one of the most important engines of economic growth for many countries. With the evolution of Information and Communication Technologies, new opportunities have arisen for a reengineering in the way the various tourism and hospitality industries interact with tourists. Equally, new possibilities open to the entities that vision to promote the patrimony and endogenous products of their regions. Information and Communication Technologies are today one of the most critical areas for the success of tourism and how tourist destinations can be promoted. Tourists, increasingly a digital generation, expect that the access to information and services be done in an innovative, immersive and contextualized way, through the use of technologies that are embedded in their daily lives. This article discusses the touristic routes creation process and the role of Information and Communication Technologies in the creation and support of touristic routes. Also, a technological model is presented in its conceptual perspective, as well the functional modelling of its main components and features.

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