2017
Autores
Barbosa, D; Pedrosa, J; Heyde, B; Dietenbeck, T; Friboulet, D; Bernard, O; D'hooge, J;
Publicação
Computerized Medical Imaging and Graphics
Abstract
In this manuscript a novel method is presented for left ventricle (LV) tracking in three-dimensional ultrasound data using a hybrid approach combining segmentation and tracking-based clues. This is accomplished by coupling an affine motion model to an existing LV segmentation framework and introducing an energy term that penalizes the deviation to the affine motion estimated using a global Lucas–Kanade algorithm. The hybrid nature of the proposed solution can be seen as using the estimated affine motion to enhance the temporal coherence of the segmented surfaces, by enforcing the tracking of consistent patterns, while the underlying segmentation algorithm allows to locally refine the estimated global motion. The proposed method was tested on a dataset composed of 24 4D ultrasound sequences from both healthy volunteers and diseased patients. The proposed hybrid tracking platform offers a competitive solution for fast assessment of relevant LV volumetric indices, by combining the robustness of affine motion tracking with the low computational burden of the underlying segmentation algorithm. © 2017 Elsevier Ltd
2017
Autores
Duraes, D; Goncalves, S; Carneiro, D; Bajo, J; Novais, P;
Publicação
INTELLIGENT SYSTEMS DESIGN AND APPLICATIONS (ISDA 2016)
Abstract
In the current world, performance is one of the most important issues concerning work and competition. Performance is strongly connected with learning and when it comes to acquiring new knowledge, attention is one the most important mechanisms as the level of the learner's attention affects learning results. When students are doing learning activities using new technologies, it is extremely important that the teacher has some feedback from the students' work in order to detect potential learning problems at an early stage. The goal of this research is to propose a system that measures the level of attentiveness in real scenarios, and detects patterns of behavior associated to different attention levels among different students. This system measures attention and uses this information for training a decision support system that shows the level of attention of a group of students in real time.
2017
Autores
Erdinc, O; Tascikaraoglu, A; Paterakis, NG; Catalao, JPS;
Publicação
2017 IEEE MANCHESTER POWERTECH
Abstract
The increasing operational complexity of power systems considering the higher renewable energy penetration and changing load characteristics, together with the recent developments in the ICT field have led to more research and implementation efforts related to the activation of the demand side. In this manner, different direct load control (DLC) and indirect load control concepts have been developed and DLC strategies are considered as an effective tool for load serving entities (LSEs) with several real-world application examples. In this study, a new DLC strategy tailored for residential air-conditioners (ACs) participating in the day-ahead planning, based on offering energy credits to the enrolled end-users is proposed. The mentioned energy credits are then used by residential end-users to lower their energy procurement costs during peak-price periods. The strategy is formulated as a stochastic mixed-integer linear programming (MILP) model considering uncertainties related to weather conditions. The outcomes regarding the end-user comfort level and economic benefits are also analyzed.
2017
Autores
Alves, Sandra; Broda, Sabine;
Publicação
Ninth Workshop on Non-Classical Models of Automata and Applications, NCMA 2017, Prague, Czech Republic, August 17-18, 2017.
Abstract
2017
Autores
Marto, AGR; de Sousa, AA; Goncalves, AJM;
Publicação
2017 12TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)
Abstract
Augmented reality has seen a fast-growing gain of interest in the last few decades. Due to technological advances, smartphones are now devices that allow to experience augmented reality systems, anytime and anywhere. Although its emerging success among users, some problems AR have been reported inhibiting its full acceptance in our digital society. The aim of this paper is to present a study about techniques to implement augmented reality systems in the cultural heritage context, including a prototype to test the technology which, based on physical objects that belong to the landscape, present an effective and accurate augmented reality approach, overlaying 3D virtual models aligned over the real images, using a smartphone's camera.
2017
Autores
Ortega, A; Pedrosa, J; Heyde, B; Tong, L; D'hooge, J;
Publicação
Applied Sciences (Switzerland)
Abstract
Fast volumetric cardiac imaging requires reducing the number of transmit events within a single volume. One way of achieving this is by limiting the field of view (FOV) of the recording to the myocardium when investigating cardiac mechanics. Although fully automatic solutions towards myocardial segmentation exist, translating that information in a fast ultrasound scan sequence is not trivial. In particular, multi-line transmit (MLT) scan sequences were investigated given their proven capability to increase frame rate (FR) while preserving image quality. The aim of this study was therefore to develop a methodology to automatically identify the anatomically relevant conically shaped FOV, and to translate this to the best associated MLT sequence. This approach was tested on 27 datasets leading to a conical scan with a mean opening angle of 19.7° ± 8.5°, while the mean "thickness" of the cone was 19° ± 3.4°, resulting in a frame rate gain of about 2. Then, to subsequently scan this conical volume, several MLT setups were tested in silico. The method of choice was a 10MLT sequence as it resulted in the highest frame rate gain while maintaining an acceptable cross-talk level. When combining this MLT scan sequence with at least four parallel receive beams, a total frame rate gain with a factor of approximately 80 could be obtained. As such, anatomical scan sequences can increase frame rate significantly while maintaining information of the relevant structures for functional myocardial imaging. © 2017 by the authors.
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