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

2018

A Decentralized Renewable Generation Management and Demand Response in Power Distribution Networks

Autores
Bahrami, S; Amini, MH; Shafie Khah, M; Catalao, JPS;

Publicação
IEEE TRANSACTIONS ON SUSTAINABLE ENERGY

Abstract
The stochastic nature of the renewable generators and price-responsive loads, as well as the high computational burden and violation of the generators' and load aggregators' privacy can make the centralized energy market management a big challenge for distribution network operators. In this paper, we first formulate the centralized energy trading as a bilevel optimization problem, which is nonconvex and includes the entities' optimal strategy to the price signals. We tackle the uncertainty issues by proposing a probabilistic load model and studying the down-side risk of renewable generation shortage. To address the nonconvexity of the centralized problem, we apply convex relaxation techniques and design proper price signals that guarantee zero relaxation gap. It enables us to address the privacy issue by developing a decentralized energy trading algorithm. For the sake of comparison, we use the dual decomposition and proximal Jacobian alternating direction method of multipliers for the algorithm design. Extensive simulations are performed on different standard test feeders to compare the CPU time of the proposed algorithm with the centralized approach and evaluate its performance in increasing the load aggregators' and generators' profit. Finally, we compare the impact of load and generation uncertainties on the optimality of the results.

2018

Strategic decision-making in the pharmaceutical industry: A unified decision-making framework

Autores
Marques, CM; Moniz, S; de Sousa, JP;

Publicação
COMPUTERS & CHEMICAL ENGINEERING

Abstract
The implementation of efficient strategic decisions such as process design and capacity investment under uncertainty, during the product development process, is critical for the pharmaceutical industry. However, to tackle these problems the widely used multi-stage/scenario-based optimization formulations are still ineffective, especially for the first-stage (here-and-now) solutions where uncertainty has not yet been revealed. This study extends the authors' previous work addressing the stochastic product-launch planning problem, by developing a new Multi-Objective Integer Programming model, embedded in a unified decision-making framework, to obtain the final design strategy that "maximizes" productivity while considering the decision-maker preferences. An approximation of the efficient Pareto-front is determined, and a subsequent Pareto solutions analysis is made to guide the decision process. The developed approach clearly identifies the process designs and production capacities that "maximize" productivity as well as the most promising solutions region for investment. Moreover, a good balance between investment and capacity allocation was achieved.

2018

Using intelligent personal assistants to assist the elderlies An evaluation of Amazon Alexa, Google Assistant, Microsoft Cortana, and Apple Siri

Autores
Reis, A; Paulino, D; Paredes, H; Barroso, I; Monteiro, MJ; Rodrigues, V; Barroso, J;

Publicação
PROCEEDINGS OF THE 2018 2ND INTERNATIONAL CONFERENCE ON TECHNOLOGY AND INNOVATION IN SPORTS, HEALTH AND WELLBEING (TISHW)

Abstract
For elderly people, social isolation is one significant factor in the deterioration of their life's quality. It has a profound impact on the general health and is produced by the diminution of social interactions. Nowadays, there is technology that can retrieve contextual data from the user's environment and interact with him in some simple, yet effective manners. The intelligent personal assistants can interact with the person by means of natural voice language. Previously, it was created a model for the adoption of electronic intelligent assistants by the elderly, as well a preliminary evaluation of the features of the intelligent personal assistants, currently available in the consumer market. In this article, it is evaluated the option of using the current consumer digital assistants to implement the proposed model. Several assistants were examined (Amazon, Google, Microsoft, and Apple), and their functionalities evaluated by creating four interaction scenarios and assessing the assistants' compliance with these scenarios.

2018

Evolution of Demand Response: A Historical Analysis of Legislation and Research Trends

Autores
Lotfi, M; Monteiro, C; Shafie Khah, M; Catalao, JPS;

Publicação
2018 TWENTIETH INTERNATIONAL MIDDLE EAST POWER SYSTEMS CONFERENCE (MEPCON)

Abstract
In the past two decades, interest in demand response (DR) schemes has grown exponentially. The need for DR has been driven by sustainability (environmental and socioeconomic) and cost-efficiency. The main premise of DR is to influence the timing and magnitude of consumption to match energy supply by sharing the benefits with consumers, ultimately aiming to optimize generation cost. As such, the first and primary enabler to DR was the establishment of contemporary electricity markets. Increased proliferation of Distributed Energy Resources (DER) and microgeneration further motivated the participation of consumers as active players in the market, popularizing DR and the wider category of Demand-Side Management (DSM) programs. Smart Grids (SG) have been an enabler to modern DR schemes, with smart metering data providing input to the underlying optimization and forecasting tools. The more recent emergence of the Internet of Energy (IoE), seen as the evolution of SG, is driven by increased Internet of Things (IoT)-enabling and high penetration of scalable and distributed energy resources. In this IoE paradigm being a fully decentralized network of energy prosumers, DR will continue to be a vital aspect of the grid in future Transactive Energy (TE) schemes, aiming for a more user-centered, energy-efficient, cost-saving, energy management approach. This paper investigates original motives and identifies the first mentions of DR in the legislative and scientific literature. Afterwards, the evolution of DR is tracked over the past four decades, attempting to study the co-influence of legislation and research by performing a thorough statistical analysis of research trends on the IEEE Xplore digital library. Finally, conclusions are made as to the current state of DR and future prospects of DR are discussed.

2018

ML datasets as synthetic cognitive experience records

Autores
Castro, H; Andrade, MT;

Publicação
International Journal of Computer Information Systems and Industrial Management Applications

Abstract
Machine Learning (ML), presently the major research area within Artificial Intelligence, aims at developing tools that can learn, approximately on their own, from data. ML tools learn, through a training phase, to perform some association between some input data and some output evaluation of it. When the input data is audio or visual media (i.e. akin to sensory information) and the output corresponds to some interpretation of it, the process may be described as Synthetic Cognition (SC). Presently ML (or SC) research is heterogeneous, comprising a broad set of disconnected initiatives which develop no systematic efforts for cooperation or integration of their achievements, and no standards exist to facilitate that. The training datasets (base sensory data and targeted interpretation), which are very labour intensive to produce, are also built employing ad-hoc structures and (metadata) formats, have very narrow expressive objectives and thus enable no true interoperability or standardisation. Our work contributes to overcome this fragility by putting forward: a specification for a standard ML dataset repository, describing how it internally stores the different components of datasets, and how it interfaces with external services; and a tool for the comprehensive structuring of ML datasets, defining them as Synthetic Cognitive Experience (SCE) records, which interweave the base audio-visual sensory data with multilevel interpretative information. A standardised structure to express the different components of the datasets and their interrelations will promote re-usability, resulting on the availability of a very large pool of datasets for a myriad of application domains. Our work thus contributes to: the universal interpretability and reusability of ML datasets; greatly easing the acquisition and sharing of training and testing datasets within the ML research community; facilitating the comparison of results from different ML tools; accelerating the overall research process. © MIR Labs.

2018

Ranked sequence positional weight heuristic for simultaneous balancing and scheduling jobs in a distributed manufacturing environment

Autores
Kays, E; Karim, A; Varela, L; Putnik, G; Avila, P;

Publicação
11TH CIRP CONFERENCE ON INTELLIGENT COMPUTATION IN MANUFACTURING ENGINEERING

Abstract
In the current competitive and globalized manufacturing scenario Distributed Manufacturing Environments are increasing, and it turns mandatory to explore improved operational approaches. For enhanced simultaneous balancing and scheduling jobs in a Distributed Manufacturing Environment (DME) a mathematical model of Ranked Sequence Positional Weight (RSPW) is proposed. The model capabilities are analysed through a test problem and the results have demonstrated that the proposed RSPW heuristics mathematical model do perform better than other competitive approaches. (C) 2017 The Authors. Published by Elsevier B.V.

  • 2058
  • 4496