Open University of Catalonia

About: Open University of Catalonia is a education organization based out in Barcelona, Spain. It is known for research contribution in the topics: Collaborative learning & Educational technology. The organization has 1943 authors who have published 4646 publications receiving 64200 citations. The organization is also known as: Universitat Oberta de Catalunya & UOC.

The SR-GCWS hybrid algorithm for solving the capacitated vehicle routing problem

Abstract: The capacitated vehicle routing problem (CVRP) is a well known problem which has long been tackled by researchers for several decades now, not only because of its potential applications but also due to the fact that CVRP can be used to test the efficiency of new algorithms and optimization methods. The objective of our work is to present SR-GCWS, a hybrid algorithm that combines a CVRP classical heuristic with Monte Carlo simulation using state-of-the-art random number generators. The resulting algorithm is tested against some well-known benchmarks. In most cases, our approach is able to compete or even outperform much more complex algorithms, which is especially interesting if we consider that our algorithm does not require any previous parameter fine-tuning or set-up process. Moreover, our algorithm has been able to produce high-quality solutions almost in real-time for most tested instances. Another important feature of the algorithm worth mentioning is that it uses a randomized constructive heuristic, capable of generating hundreds or even thousands of alternative solutions with different properties. These alternative solutions, in turn, can be really useful for decision-makers in order to satisfy their utility functions, which are usually unknown by the modeler. The presented methodology may be a fine framework for the development of similar algorithms for other complex combinatorial problems in the routing arena as well as in some other research fields.

Folded Recurrent Neural Networks for Future Video Prediction

Abstract: This work introduces double-mapping Gated Recurrent Units (dGRU), an extension of standard GRUs where the input is considered as a recurrent state. An extra set of logic gates is added to update the input given the output. Stacking multiple such layers results in a recurrent auto-encoder: the operators updating the outputs comprise the encoder, while the ones updating the inputs form the decoder. Since the states are shared between corresponding encoder and decoder layers, the representation is stratified during learning: some information is not passed to the next layers. We test our model on future video prediction. Main challenges for this task include high variability in videos, temporal propagation of errors, and non-specificity of future frames. We show how only the encoder or decoder needs to be applied for encoding or prediction. This reduces the computational cost and avoids re-encoding predictions when generating multiple frames, mitigating error propagation. Furthermore, it is possible to remove layers from a trained model, giving an insight to the role of each layer. Our approach improves state of the art results on MMNIST and UCF101, being competitive on KTH with 2 and 3 times less memory usage and computational cost than the best scored approach.

Worldwide adherence to Mediterranean Diet between 1960 and 2011

Abstract: From the 1960s to the early 21st-century adherence to the Mediterranean diet (MD) declined around the world. This was partly due to the westernization of eating habits. However, in the last decade a new variable came into play, the economic crisis, which may have affected dietary patterns. We analyzed worldwide trends of adherence to the MD between the periods 1961–1965, 2000–2003 and 2004–2011. Data was obtained from the Food and Agriculture Organization Food Balance Sheets in three study periods: 1961–1965, 2000–2003 and 2004–2011. The Mediterranean Adequacy Index (MAI) was calculated for 41 selected countries using the averages of available energy intake for different food groups. Changes in MAI indicated the trends in adherence in the different periods. In many countries, MAI deteriorated from 1961 to 1965 and 2004 to 2011, yet an increase was observed in 16 countries. Between the last two observation periods, MAI values stabilized in 16 of the 41 selected countries. Regional rankings for the three study periods based on descending MAI scores were: Southern Mediterranean, Mediterranean Europe, Central Europe and Northern Europe. Adherence to the MD significantly decreased between 1961–65 and 2000–03, whereas from 2004–2011 there was a stabilization of MAI values and even an increase among 16 countries. Efforts are needed to preserve the dietary traditions and lifestyle habits within the Mediterranean region in order to counteract increasing rates of chronic disease.

Causal Frequency-Specific Contributions of Frontal Spatiotemporal Patterns Induced by Non-Invasive Neurostimulation to Human Visual Performance

Abstract: Neural oscillatory activity is known to play a crucial role in brain function. In the particular domain of visual perception, specific frequency bands in different brain regions and networks, from sensory areas to large-scale frontoparietal systems, have been associated with distinct aspects of visual behavior. Nonetheless, their contributions to human visual cognition remain to be causally demonstrated. We hereby used non-uniform (and thus non-frequency-specific) and uniform (frequency-specific) high-beta and gamma patterns of noninvasive neurostimulation over the right frontal eye field (FEF) to isolate the behavioral effects of oscillation frequency and provide causal evidence that distinct visual behavioral outcomes could be modulated by frequency-specific activity emerging from a single cortical region. In a visual detection task using near-threshold targets, high-beta frequency enhanced perceptual sensitivity (d') without changing response criterion (beta), whereas gamma frequency shifted response criterion but showed no effects on perceptual sensitivity. The lack of behavioral modulations by non-frequency-specific patterns demonstrates that these behavioral effects were specifically driven by burst frequency. We hypothesize that such frequency-coded behavioral impact of oscillatory activity may reflect a general brain mechanism to multiplex functions within the same neural substrate. Furthermore, pathological conditions involving impaired cerebral oscillations could potentially benefit in the near future from the use of neurostimulation to restore the characteristic oscillatory patterns of healthy systems.

Social media in health - what are the safety concerns for health consumers?

Abstract: Recent literature has discussed the unintended consequences of clinical information technologies (IT) on patient safety, yet there has been little discussion about the safety concerns in the area of consumer health IT. This paper presents a range of safety concerns for consumers in social media, with a case study on YouTube. We conducted a scan of abstracts on 'quality criteria' related to YouTube. Five areas regarding the safety of YouTube for consumers were identified: (a) harmful health material targeted at consumers (such as inappropriate marketing of tobacco or direct-to-consumer drug advertising); (b) public display of unhealthy behaviour (such as people displaying self-injury behaviours or hurting others); (c) tainted public health messages (i.e. the rise of negative voices against public health messages); (d) psychological impact from accessing inappropriate, offensive or biased social media content; and (e) using social media to distort policy and research funding agendas. The examples presented should contribute to a better understanding about how to promote a safe consumption and production of social media for consumers, and an evidence-based approach to designing social media interventions for health. The potential harm associated with the use of unsafe social media content on the Internet is a major concern. More empirical and theoretical studies are needed to examine how social media influences consumer health decisions, behaviours and outcomes, and devise ways to deter the dissemination of harmful influences in social media.