Cookies
O website necessita de alguns cookies e outros recursos semelhantes para funcionar. Caso o permita, o INESC TEC irá utilizar cookies para recolher dados sobre as suas visitas, contribuindo, assim, para estatísticas agregadas que permitem melhorar o nosso serviço. Ver mais
Aceitar Rejeitar
  • Menu
Publicações

2016

Virtual Atmosphere, Emotions, Attitudes and Real Use

Autores
Moreira, AC; Ferreira, MM; Macedo, P;

Publicação
Advances in Marketing, Customer Relationship Management, and E-Services - Managing Public Relations and Brand Image through Social Media

Abstract
This study involves several theories, namely: the theory of reasoned action, the technology acceptance model, the theory of planned behavior and the internet banking acceptance model. It aims to understand the relationships between the virtual atmosphere and emotional states, how the individual characteristics (social identity, altruism and telepresence) and emotional states influence attitudes, and how attitudes, past experience and trust influence actual use of a site. To this end, the authors developed three conceptual models explaining the relationships among the above-mentioned variables. Methodologically, descriptive statistics, exploratory factor analysis and the generalized maximum entropy estimator are used to test the three models in a wedding site. Of the eight hypotheses proposed, one can only partially validate hypotheses h1, h2, h3 and h6, while hypothesis h7 is accepted and the remaining are rejected.

2016

Simulation of the operation of hydro plants in an electricity market using Agent Based Models - introducing a Q Learning approach

Autores
Sousa, JC; Saraiva, JT;

Publicação
2016 13TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET (EEM)

Abstract
The restructuring of power systems with the introduction of electricity markets and decentralized structures increased the number of participating entities. This is particularly true in generation and retailing which are now provided under competition. Accordingly, it is important to develop models to simulate the behavior of these agents and to optimize their participation in electricity markets. Among them, it is essential to adequately model generation agents namely in countries having a large share of hydro stations. This paper describes an agent-based approach to model the day-ahead electricity market having a particular emphasis on hydro generation. Apart from the characterization of the agents, the paper details the introduction of the Q-Learning algorithm in the model as a way to enhance the performance of generation agents. This paper also presents some preliminary results taking the Portuguese generation system as an example.

2016

InGaZnO TFT behavioral model for IC design

Autores
Bahubalindrun, P; Tavares, V; Barquinha, P; de Oliveira, PG; Martins, R; Fortunato, E;

Publicação
ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING

Abstract
This paper presents a behavioral model for amorphous indium-gallium-zinc oxide thin-film transistor using artificial neural network (ANN) based equivalent circuit (EC) approach to predict static and dynamic behavior of the device. In addition, TFT parasitic capacitances (C-GS and C-GD) characterization through measurements is also reported. In the proposed model, an EC is derived from the device structure, in terms of electrical lumped elements. Each electrical element in the EC is modeled with an ANN. Then these ANNs are connected together as per the EC and implemented in Verilog-A. The proposed model performance is validated by comparing the circuit simulation results with the measured response of a simple common-source amplifier, which has shown 12.2 dB gain, 50 mu W power consumption and 85 kHz 3-dB frequency with a power supply of 6 V. The same circuit is tested as an inverter and its response is also presented up to 50 kHz, from both simulations and measurements. These results show that the model is capable of capturing both small and large signal behavior of the device to good accuracy, even including the harmonic distortion of the signal (that emphasizes the nonlinear behavior of the parasitic capacitance), making the model suitable for IC design.

2016

Basic Analog and Digital Circuits with a-IGZO TFTs

Autores
Bahubalindruni, PG; Tavares, V; Barquinha, P; Martins, R; Fortunato, E;

Publicação
2016 13TH INTERNATIONAL CONFERENCE ON SYNTHESIS, MODELING, ANALYSIS AND SIMULATION METHODS AND APPLICATIONS TO CIRCUIT DESIGN (SMACD)

Abstract
This paper presents the characterization of fundamental analog and digital circuits with a-IGZO TFTs from measurements performed at normal ambient. The fundamental blocks considered in this work include digital logic gates, a low power single stage high-gain amplifier with capcacitive bootstrapping and a level shifter/buffer. These circuits are important functional blocks in analog/Mixed signal IC design with oxide TFTs. Being fabricated at low temperature (<200 degrees C), they can find potential applications in low-cost large-area flexible systems.

2016

Optimization of the Variable Speed Pump Storage Participation in Frequency Restoration Reserve Market

Autores
Filipe, JM; Moreira, CL; Bessa, RJ; Silva, BA;

Publicação
2016 13TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET (EEM)

Abstract
Several countries have a significant installed capacity of large-scale reversible hydro power plants. This large-scale storage technology comes with high investments costs, hence the constant search for methods to increase and diversify the sources of revenue. Traditional fixed speed pump storage units typically operate in the day-ahead market to perform price arbitrage and, in specific cases, provide downward replacement reserve (RR). Variable speed pump storage can not only participate in RR but also contribute to frequency restoration reserve (FRR), given their ability to control its operating point in pumping mode. This work proposes a strategy to manage the water resource and maximize the power plant revenue by participating in the day ahead market but also providing ancillary services. Moreover, a model to correctly allocate the water resource throughout the year is presented, as well as an evaluation module to calculate the real revenue of the system.

2016

Usability evaluation of an entertainment platform by people with intellectual disabilities

Autores
Rocha, T; Carvalho, D; Gonçalves, R; Martins, J; Branco, F; Bessa, M;

Publicação
2016 11TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)

Abstract
In this paper it is presented a usability evaluation of an entertainment platform, well-known, YouTube. The main aim is to study how people with intellectual disabilities interact with the layout and uses their search field option. We intended to observe and analyze performance and satisfaction but also if the interface can give them autonomy on the search option. The results show that participants had a good experience with the interface, however cannot be autonomy with the search option.

  • 2442
  • 4362