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Publications

2018

Decision Support for Negotiations among Microgrids Using a Multiagent Architecture

Authors
Pinto, T; Ghazvini, MAF; Soares, J; Faia, R; Corchado, JM; Castro, R; Vale, Z;

Publication
ENERGIES

Abstract
This paper presents a decision support model for negotiation portfolio optimization considering the participation of players in local markets (at the microgrid level) and in external markets, namely in regional markets, wholesale negotiations and negotiations of bilateral agreements. A local internal market model for microgrids is defined, and the connection between interconnected microgrids is based on nodal pricing to enable negotiations between nearby microgrids. The market environment considering the local market setting and the interaction between integrated microgrids is modeled using a multi-agent approach. Several multi-agent systems are used to model the electricity market environment, the interaction between small players at a microgrid scale, and to accommodate the decision support features. The integration of the proposed models in this multi-agent society and interaction between these distinct specific multi-agent systems enables modeling the system as a whole and thus testing and validating the impact of the method in the outcomes of the involved players. Results show that considering the several negotiation opportunities as complementary and making use of the most appropriate markets depending on the expected prices at each moment allows players to achieve more profitable results.

2018

LearnJS - A JavaScript Learning Playground (Short Paper)

Authors
Queirós, R;

Publication
7th Symposium on Languages, Applications and Technologies, SLATE 2018, June 21-22, 2018, Guimaraes, Portugal

Abstract
The JavaScript ecosystem is evolving dramatically. Nowadays, the language is no longer confined to the boundaries of the browser and is now running in both sides of the Web stack. At the same time, JavaScript it’s starting to play also an important role in desktop and mobile applications development. These facts are leading companies to massively adopt JavaScript in their Web/mobile projects and schools to augment the language spectrum among their courses curricula. Several platforms appeared in recent years aiming to foster the learning of the JavaScript language. Those platforms are mainly characterized with sophisticated UI which allow users to learn JavaScript in a playful and interactive way. Despite its apparent success, these environments are not suitable to be integrated in existent educational platforms. Beyond these interoperability issues, most of these platforms are rigid not allowing teachers to contribute with new exercises, organize the existent exercises in more suitable and modular activities to be deployed in their courses, neither keep track of student’s progress. This paper presents LearnJS as a simple and flexible platform to teach and learn JavaScript. In this platform, instructors can contribute with new exercises and combine them with expositive resources (e.g videos) to define specific course activities. These activities can be gamified with the injection of dynamic attributes to reward the most successful attempts. Finally, instructors can deploy activities in their educational platforms. On the other hand, learners can solve exercises and receive immediate feedback on their solutions through static and dynamic analyzers. Since we are in the early stages of implementation, the paper focus on the presentation of the LearnJS architecture, their main components and their data and integration models. Nevertheless, a prototype of the platform is available in a GitHub repository. © Ricardo Queirós

2018

Framework for Software Code Reviews and Inspections in a Classroom Environment

Authors
Almeida, F; Faculty of Engineering of Oporto University, INESC TEC, Porto, Portugal,;

Publication
International Journal of Modern Education and Computer Science

Abstract

2018

Behavior of the Iberian Electricity Market Prices in 2016 Considering Increasing Values of Feed-in Generation

Authors
Teixeira, JP; Saraiva, JT;

Publication
2018 15TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET (EEM)

Abstract
This paper results from the research conducted by the first author during the preparation of his MSc Thesis. This research aimed at investigating the impact on the market prices of the Iberian Electricity Market, MIBEL, due to increases of the feed-in generation, as such an increase is expected to occur in the next few years, namely for PV systems. This research was conducted using real market data publicly available in the web site of the Iberian Market Operator for 2016. To estimate this impact, for each trading hour of 2016 we considered new segments at price 0,0 (sic)/MWh to translate the priority given to this type of generation. These segments representing the new feed-in generation were then used together with the selling bids submitted by market agents to build the new aggregated selling curve. The new market price was finally obtained as the intersection of the new selling curve with the original buying curve, that was assumed unchanged. The global result indicates that if the feed-in generation increases by 25% regarding the values of 2016, then the average annual market price decreases by 6,57 % regarding the original value of 39,42 (sic)/MWh.

2018

Cell-free layer measurements of in vitro blood flow in a microfluidic network: an automatic and manual approach

Authors
Bento, D; Pereire, AI; Lima, J; Miranda, JM; Lima, R;

Publication
COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING-IMAGING AND VISUALIZATION

Abstract
In microcirculation, the cell-free layer (CFL) is a well-known physiological phenomenon that plays an important role in reducing the flow resistance and in balancing nitric oxide (NO) production by endothelial cells and NO scavenging by red blood cells. To better understand this phenomenon, several blood flow studies have been performed in simple geometries at both in vivo and in vitro environments. However, to date little information is available regarding the effects imposed by a complex branching network on the CFL.The present study shows the CFL layer variation at a microchannel network.The images were captured using a high-speed video microscopy system and the thickness of the CFL was measured using both manual and automatic image analysis techniques. Using this methodology, it was possible to visualise the in vitro blood flowing through the network and to identify several flow phenomena that happen in microcirculation. Overall, the results have shown that the concentration of cells and the geometrical configuration of the network have a major impact on the CFL thickness. In particular, the thickness of the CFL decreases as the fluid flows through a microchannel network composed with successive smaller channels. It was also clear that, for the full length of the network, the CFL thickness tends to decrease with the increase of the concentration of cells. The automatic method developed becomes inaccurate for high haematocrit and needs be calibrated by manual methods for Hcts bigger than 10%. The results obtained from this study could help the development and validation of multiscale numerical models able to take into account the CFL for simulating microvascular blood flow.

2018

Emulation-in-the-loop for simulation and testing of real-time critical CPS

Authors
Oliveira, PR; Meireles, M; Maia, C; Pinho, LM; Gouveia, G; Esteves, J;

Publication
Proceedings - 2018 IEEE Industrial Cyber-Physical Systems, ICPS 2018

Abstract
Complex cyber-physical systems are more and more a set of components working tightly coupled, with little or no human intervention. Assessing the correctness of these systems by testing components individually, one-by-one, is obviously not sufficient, being required to also test and validate the overall system. KhronoSim is a modular and extensible platform for testing cyber-physical systems in closed-loop, which enables the integration of simulation models and platform emulators to build a closed loop test environment. This paper presents the emulator module of KhronoSim, developed to integrate the well-known QEMU emulator in the closed-loop testing platform. © 2018 IEEE.

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