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Publications

2019

Predictive multi-view content buffering applied to interactive streaming system

Authors
Costa, TS; Andrade, MT; Viana, P;

Publication
ELECTRONICS LETTERS

Abstract
This Letter discusses the benefits of introducing Machine Learning techniques in multi-view streaming applications. Widespread use of machine learning techniques has contributed to significant gains in numerous scientific and industry fields. Nonetheless, these have not yet been specifically applied to adaptive interactive multimedia streaming systems where, typically, the encoding bit rate is adapted based on resources availability, targeting the efficient use of network resources whilst offering the best possible user quality of experience (QoE). Intrinsic user data could be coupled with such existing quality adaptation mechanisms to derive better results, driven also by the preferences of the user. Head-tracking data, captured from camera feeds available at the user side, is an example of such data to which Recurrent Attention Models could be applied to accurately predict the focus of attention of users within videos frames. Information obtained from such models could be used to assist a preemptive buffering approach of specific viewing angles, contributing to the joint goal of maximising QoE. Based on these assumptions, a research line is presented, focusing on obtaining better QoE in an already existing multi-view streaming system

2019

Integration of emerging resources in IGDT-based robust scheduling of combined power and natural gas systems considering flexible ramping products

Authors
Mirzaei, MA; Sadeghi Yazdankhah, A; Mohammadi Ivatloo, B; Marzband, M; Shafie khah, M; Catalao, JPS;

Publication
ENERGY

Abstract
Wind energy sources have created new challenges in power system scheduling to follow the network load. Gas fired units with high ramping could better deal with inherent uncertainties of wind power compared to other power generation sources. The natural gas system constraints affect the flexibility of natural gas- fired power plants in the electrical market. In this paper, three solutions have been proposed to cover the challenges of gas system constraints and the uncertainty of wind power: 1) using information-gap decision theory (IGDT) based robust approach to address the uncertainty caused by the intrinsic nature of wind power, 2) Integration of compressed air energy storage (CAES), and demand response (DR) in day-ahead scheduling and 3) considering flexible ramping products in order to ensure reliable operations, there must be enough ramp to eliminate the variability of wind power in real-time dispatch stage. This paper proposes an IGDT-based robust security constrained unit commitment (SCUC) model for coordinated electricity and natural gas systems with the integration of wind power and emerging flexible resources while taking the flexible ramping products into account. Numerical tests demonstrate the effect of emerging flexible resources on a reduction of system operation cost and the uncertainty of predicted wind power.

2019

Development of an Electrohydraulic Variable Buoyancy System

Authors
Carneiro, JF; Pinto, JB; Cruz, NA; de Almeida, FG;

Publication
INFORMATION

Abstract
The growing needs in exploring ocean resources have been pushing the length and complexity of autonomous underwater vehicle (AUV) missions, leading to more stringent energy requirements. A promising approach to reduce the energy consumption of AUVs is to use variable buoyancy systems (VBSs) as a replacement or complement to thruster action, since VBSs only require energy consumption during limited periods of time to control the vehicle's floatation. This paper presents the development of an electrohydraulic VBS to be included in an existing AUV for shallow depths of up to 100 m. The device's preliminary mechanical design is presented, and a mathematical model of the device's power consumption is developed, based on data provided by the manufacturer. Taking a standard mission profile as an example, a comparison between the energy consumed using thrusters and the designed VBS is presented and compared.

2019

What Is the Effect of New Technologies on People with Ages Between 45 and 75?

Authors
Fontoura, A; Fonseca, F; Mar Piñuel, MD; Canelas, MJ; Gonçalves, R; Yong Oliveira, MA;

Publication
New Knowledge in Information Systems and Technologies - Volume 3

Abstract
When we look around us, we see people of all ages using all kinds of technology, more specifically, devices like cellphones are used by younglings, adults and older people. There is no escaping it. Consequently, we decided to analyse how technologies affect the lives of these men and women, focusing on an older age group, mainly because of the lack of studies that focus on people over 65. If most of them are able to speak, focus, and learn, how many of them have given in to the new waves of evolution that have feasted on the world for the past few years? That is exactly what we are trying to find out: How older people react to new technology (more specifically to information and communication technologies or ICT), how often and how they use it. For this study, we decided to focus on the littoral north of Portugal, given that the author-group’s members live along the coast line. A survey was performed (with 56 valid responses) as were eight interviews. Regarding the view that the older people we have interviewed have of millennials, most of our respondents show some concern. Notably, they see the Internet as an addiction of the younger elements in society, contributing to them getting into trouble, losing interest in school, meeting up with strangers and only being concerned with being popular on social media. As concerns ICT usage by elders, the psychological component of the “I can’t" does not help them. © Springer Nature Switzerland AG 2019.

2019

Urban Mobility Digitalization: Towards Mobility as a Service (MaaS)

Authors
Barreto, L; Amaral, A; Baltazar, S;

Publication
9th International Conference on Intelligent Systems 2018: Theory, Research and Innovation in Applications, IS 2018 - Proceedings

Abstract
Population in the cities grows every day posing new challenges that need to be properly addressed throughout the planning and design of sustainable and smart cities - cities of the future. Mobility is an important issue considering social inclusion and the sustainable development of such cities. Thus, future mobility will have an increased importance when having to plan and design the cities of tomorrow. A key component of any future mobility and its metabolism is what is known as Mobility as a Service (MaaS), representing emerging opportunities from any type or mode of transportation in future cities. Through an empirical and explorative research methodology, this paper presents the main APP's/platforms characteristics, regarding the European territory, towards an integrated and sustainable mobility. Concluding, we present some features and trends that should be considered in the development of future MaaS systems, allowing a more convenient provision of versatile and attractive mobility services. © 2018 IEEE.

2019

Modeling a Large-Scale Battery Energy Storage System for Power Grid Application Analysis

Authors
Rancilio, G; Lucas, A; Kotsakis, E; Fulli, G; Merlo, M; Delfanti, M; Masera, M;

Publication
Energies

Abstract
The interest in modeling the operation of large-scale battery energy storage systems (BESS) for analyzing power grid applications is rising. This is due to the increasing storage capacity installed in power systems for providing ancillary services and supporting nonprogrammable renewable energy sources (RES). BESS numerical models suitable for grid-connected applications must offer a trade-off, keeping a high accuracy even with limited computational effort. Moreover, they are asked to be viable in modeling for real-life equipment, and not just accurate in the simulation of the electrochemical section. The aim of this study is to develop a numerical model for the analysis of the grid-connected BESS operation; the main goal of the proposal is to have a test protocol based on standard equipment and just based on charge/discharge tests, i.e., a procedure viable for a BESS owner without theoretical skills in electrochemistry or lab procedures, and not requiring the ability to disassemble the BESS in order to test each individual component. The BESS model developed is characterized by an experimental campaign. The test procedure itself is framed in the context of this study and adopted for the experimental campaign on a commercial large-scale BESS. Once the model is characterized by the experimental parameters, it undergoes the verification and validation process by testing its accuracy in simulating the provision of frequency regulation. A case study is presented for the sake of presenting a potential application of the model. The procedure developed and validated is replicable in any other facility, due to the low complexity of the proposed experimental set. This could help stakeholders to accurately simulate several layouts of network services.

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