2018
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
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
Authors
Barreto, L; Amaral, AM; Pereira, T; Carvalho, F;
Publication
Mobile Applications and Solutions for Social Inclusion
Abstract
The economic and social challenges felt in recent years because of the financial crisis impact wave were somehow attenuated by the silent work provided by the third sector institutions. Therefore, the incessant instability of the markets, as well as the population life-expectancy increasing and the implications thereof require new approaches towards pointing strategies to mitigate these problematic situations. For that reason, the development of technological solutions and applications for the private social solidarity institutions is an utmost challenge towards guaranteeing their sustainability and efficiency over time. The adoption of such solutions should be properly conceived to enhance their efficiency of the daily routines and to fulfill and inclusion of all users, while trying to reduce the technological literacy. The development of a technological framework to support the adoption of the practices, selection of technical requirements, and functionalities is seen as a great contribution for setting the roadmap that should be followed. This chapter explores the development of a framework for technological embedding in private social solidarity institutions. © 2018, IGI Global.
2018
Authors
Carvalho, D; Bessa, M; Magalhaes, L; Carrapatoso, E;
Publication
UNIVERSAL ACCESS IN THE INFORMATION SOCIETY
Abstract
With the thriving of different natural interaction paradigms-such as gesture-based interfaces-it becomes important to understand how these novel interfaces can influence users' performance when it comes to their age. Recent advances made in human-computer interaction allow us to manipulate digital contents more intuitively; however, no work has yet been reported that systematically evaluates how gestural interfaces may influence the performance of different user groups. Different optical sensors, which allow human body acquisition with reliable accuracy, have been released, and with the appearance of such controllers for gesture recognition, it becomes important to understand if different age-related groups display similar performance levels concerning gestural interaction, or, on the other hand, if specific sensors could induce better results than others when dealing with users of different age brackets. In this article, we compare two gesture-sensing devices (Microsoft Kinect and Leap Motion) using the Fitts' law model to evaluate target acquisition performance, with relation to three user groups: children, young adults and older adults. This case study involved 60 participants that were asked to perform a simple continuous selection task as quickly and accurately as possible using one of the devices for gestural recognition. Indeed, performance results showed statistically significant differences among the age groups in the selection task accomplished. However, when considering the users' performance with regard to both input devices compared side by side, there were no significant differences in each group of users. We believe this situation could imply that the device itself might not have influenced the users' performance, but actually the users' age might. The participants feedback was interesting on account of their behaviors and preferences: Although there are no significant differences in performance, there could be when it comes to user preference.
2018
Authors
Cunha, A; Macedo, N;
Publication
Abstract State Machines, Alloy, B, TLA, VDM, and Z - 6th International Conference, ABZ 2018, Southampton, UK, June 5-8, 2018, Proceedings
Abstract
This paper reports on the development of a formal model for the Hybrid ERTMS/ETCS Level 3 concept in Electrum, a lightweight formal specification language that extends Alloy with mutable relations and temporal logic operators. We show how Electrum and its Analyzer can be used to perform scenario exploration to validate this model, namely to check that all the example operational scenarios described in the reference document are admissible, and to reason about expected safety properties, which can be easily specified and model checked for arbitrary track configurations. The Analyzer depicts scenarios (and counter-examples) in a graphical notation that is logic-agnostic, making them understandable for stakeholders without expertise in formal specification. © Springer International Publishing AG, part of Springer Nature 2018.
2018
Authors
Matos, T; Nobrega, R; Rodrigues, R; Pinheiro, M;
Publication
WEB3D 2018: THE 23RD INTERNATIONAL ACM CONFERENCE ON 3D WEB TECHNOLOGY
Abstract
The use of 360 degrees videos has been increasing steadily in the 2010s, as content creators and users search for more immersive experiences. The freedom to choose where to look at during the video may hinder the overall experience instead of enhancing it, as there is no guarantee that the user will focus on relevant sections of the scene. Visual annotations superimposed on the video, such as text boxes or arrow icons, can help guide the user through the narrative of the video while maintaining freedom of movement. This paper presents a web-based immersive visualizer for 360. videos that contain dynamic media annotations, rendered in real-time. A set of annotations was created with the purpose of providing information or guiding the user to points of interest. The visualizer can be used with a computer, using a keyboard and mouse or HTC Vive, and in mobile devices with Cardboard VR headsets, to experience the video in virtual reality, which is made possible with the WebVR API. The visualizer was evaluated through usability tests, to analyze the impact of different annotation techniques on the users' experience. The obtained results demonstrate that annotations can assist in guiding the user during the video, and a careful design is imperative so that they are not intrusive and distracting for the viewers.
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