ALBERT

Description: This paper proposes a low-complexity small signal model for a 3-leg converter connected to a balanced three-phase, three-wire weak grid and synchronised to this grid using a PLL implemented in a synchronous rotating d-q axis. A thorough analysis of the system stability as a function of the PLL bandwidth and the short circuit ratio (SCR) of the grid is performed based on a linearised model. By using the proposed model, an improved design process is proposed for the commonly used dq-PLL that accounts for the potential stability issues which may occur in weak grids. Using the proposed approach, it is possible to optimise the PLL design to find the fastest PLL that can operate stably considering the SCR of the grid. In addition, the proposed model is very simple, resulting in a straightforward design tool that could also be used for online stability monitoring. The method is validated through simulations and experimental results from a 5kW laboratory system.

Description: Coastal floods have become a serious problem on a global scale, increasing in frequency or magnitude due to natural conditions, and exacerbated by socioeconomic factors. This investigation analyzes the role of tides and average sea levels on the development and intensity of flooding in the lower section of the Andalién River, located toward the southern extreme of the coast of central Chile and northeast of Concepción, the country’s second most populous city. Numerical simulation (1D) was used in five modeled scenarios to determine potential flooding areas, demonstrating the influence of tides in flooding processes as far away as 7.3 km from the river mouth, which is reinforced by the fact that 57% of flooding events occur during syzygies. Further, a climate change-induced sea level rise of 60 cm from current levels by the end of the 21st century would produce a 4% increase in flood-prone areas, with 17% of flooding affecting the current built-up area and 83% of floodplains and salt marshes. Efforts must be made to protect or conserve these latter areas in order to increase natural resilience, given the high costs of implementing structural measures to protect future residential areas.

Description: This paper combines Bayesian networks (BN) and information theory to model the likelihood of severe loss of separation (LOS) near accidents, which are considered mid-air collision (MAC) precursors. BN is used to analyze LOS contributing factors and the multi-dependent relationship of causal factors, while Information Theory is used to identify the LOS precursors that provide the most information. The combination of the two techniques allows us to use data on LOS causes and precursors to define warning scenarios that could forecast a major LOS with severity A or a near accident, and consequently the likelihood of a MAC. The methodology is illustrated with a case study that encompasses the analysis of LOS that have taken place within the Spanish airspace during a period of four years.

Description: Background: Chronic diseases are currently the main cause of morbidity and mortality and represent a major challenge to healthcare systems. The objective of this study is to know Spanish public opinion about chronic disease and how it affects their daily lives. Methods: Through a telephone or online survey of 24 questions, data was gathered on the characteristics of the respondents and their knowledge and experiences of chronic diseases. Results: Of the 2522 survey respondents, 325 had a chronic disease and were carers, 1088 had a chronic disease and were not carers, 140 did not have a chronic disease but were carers, and 969 did not have chronic disease and were not carers. The degree of knowledge on these diseases was good or very good for 69.4%, 56.0%, 62.2%, and 46.7%, respectively, for each group. All the groups agreed that chronic diseases mainly affect mood, quality of life and having to make sacrifices. Conclusions: Knowledge about chronic diseases is relatively good, although it can be improved among the Spanish population, especially among patients who report having a chronic disease and play the role of carers. However, it is important to continue maintaining the level of information and training concerning these diseases.

Description: The aim of this study was to investigate the risk of dependency on physical exercise in individual sportspeople and the relationship with body dissatisfaction and motivation. Two hundred and twenty-five triathletes, swimmers, cyclists, and athletics competitors aged 18 to 63 years old took part in the study, of which 145 were men (M = 35.57 ± 10.46 years) and 80 were women (M = 32.83 ± 10.31 years). The EDS-R (Exercise Dependence Scale-Revised) was used to study dependency on exercising, the Body Shape Questionnaire (BSQ) was used to study body dissatisfaction, the Behaviour Regulation in Exercise Questionnaire (BREQ-3) was used to determine the participants’ motivation and the BIAQ was used to analyse conducts of avoidance to body image. The obtained results show that 8.5% of the subjects have a risk of dependency on exercise and 18.2% tend to have corporal dissatisfaction, without meaningful differences in the kind of sport they practiced. However, there were important differences concerning the dependency on physical exercise (15% vs. 4.8%) and body dissatisfaction (31.1% vs. 11%) in relation to sex, with the higher percentages referring to women. Introjected regulation and the conduct of food restriction were predictor variables of the dependency on exercise and corporal dissatisfaction. Also, the number and duration of sessions; the age of the participants; the integrated, introjected, and external regulations surrounding social activities; and eating restraints could all predict dependence on physical exercise (DPE).

Description: The impacts that climate change and land-use dynamics have on biodiversity are already visible in the distribution and behaviour of a large number of species. By using a Bayesian framework, including land-use, meteorological, topography and other variables as explanatory variables, such as distance to roads and urban centres, we modeled a number of species within each cell of a regular lattice for Catalonia, Spain, in the period of 2004 to 2010. We estimated a slight increase in daily maximum temperature and a more significant increase in minimum temperature (a 5-year increase of 0.159 °C in maximum temperature, and an increase of 0.332 °C in minimum temperature). The estimation shows that the total number of species was greater than expected in the cells where land use was not urban—38.4%, in forests and 55.2% in mixed forests. Finally, we observed that most invasive species are found in areas where the minimum temperature is expected to increase. Our study can help with making important recommendations as to where, when and how future threats could affect specie distribution and the kind of planning processes needed for when protected natural areas will be unable to continue to support all the species they were designed to protect.

Description: For a significant number of people with visual impairments, public transport plays an important role in productivity, community participation, and independence, since it may be the only feasible mobility option to participate in their education, work, medical care, food, and to attend many other places in their community. To use the public bus system safely, effectively, and autonomously, these people need to collect information about their physical environment and visible information at stops and terminals, such as timetables, routes, etc. Unfortunately, most people who are blind or visually impaired experience difficulties in getting on the right bus or getting off at the right destination. These situations usually force them to depend on other people that assist them in activities close to their homes, or settle for simpler jobs, or simply stay at home. Therefore, our efforts should aim to develop a system where technology is used to empower people with visual disabilities, allowing them to navigate autonomously in the public transport system. This paper presents a system based on radio frequency (RF) communication proposed within the framework of the MOVIDIS (Mobility for Visually Disabled People) research project (funded by the National Secretariat of Science, Technology and Innovation-SENACYT, under Grants No. 109-2015-4-FID14-073 and No. 99-2018-4-FID17-031), which provides an alternative to assist people with visual disabilities with their mobility in the public transport system. The various modules of this system communicate with each other by means of radio frequency and allow users to interact with buses and their respective stops. The first experimental results show that RF communication represents a viable option to help people with visual disabilities in public transport services.

Description: This paper aims to present the application of a fishbone sequential diagram in air traffic management (ATM) incident investigations performing as a key connection between safety occurrence analysis methodology (SOAM) and accident/incident data reporting (ADREP) approaches. SOAM analysis is focused on organizational cause detection; nevertheless, this detection of individual causes from a complete incident scenario presents a complex analysis, and even more, the chronological relationship between causes, which is lacking in SOAM, should be tracked for post-investigation analysis. The conventional fishbone diagram is useful for failure cause classification; however, we consider that this technique can also show its potential to establish temporal dependencies between causes, which are categorized and registered with ADREP taxonomy for future database creation. A loss of separation incident that occurred in the Edmonton area (Canada) is used as a case study to illustrate this methodology as well as the whole analysis process.

Description: Background: The main purpose of this research was to determine the stability of three different sanitary shoes on nurses with eyes open and closed with respect to barefoot condition. In addition, the secondary aim was to determine the reliability of stability measurements under these different conditions. Methods: A crossover quasi-experimental study (NCT03764332) was performed. Twenty-six nurses who wore different sanitary shoes (Eva Plus Ultralight®, Gym Step® and Milan-SCL Liso®) were evaluated with respect to barefoot condition for stability measures on the Podoprint® podobarometric and stabilometry tool and with eyes open and closed. Furthermore, the reliability of stability measurements was determined by the intraclass correlation coefficient (ICC) under these different conditions. Results: Between-groups comparisons of the static and stabilometry podobarometric data with eyes open showed statistically significant differences (p 〈 0.05). Milan-SCL Liso® sanitary shoes improved podobarometric data of forefoot force and distribution with respect to barefoot condition. Eva Plus Ultralight® and Gym Step® sanitary shoes increased the stroke length mean, stroke surface mean, and anterior speed mean as well as reduced y axis displacement mean with respect to barefoot condition. Similar findings were determined for measurements with eyes closed. ICCs ranged from poor to excellent reliability (ICC = 0.010–0.995). Conclusions: Sanitary shoes improved podobarometric and stabilometry stability with respect to barefoot condition.

Description: Contemporary society is going through a cultural transition that leads to new conceptions about the ways in which human beings organize socially and communicate. This process of deep social and cultural transformations is characterized by a technological disruption, in which virtuality forms a new dimension that behaves as an extension of human intelligence. This new form of human interaction impacts on the social imagination, demanding one to rethink social and educational paradigms for the two-dimensional citizen. In this context, this research article describes the sociological importance and the process of social adaptation of users to a personal learning environment (PLE). It includes the validation process of an instrument for the study of the PLE of 8th grade students belonging to 15 schools in the Biobío Region of Chile. A PLE is a frame of reference that can help to understand how two-dimensional citizens socially adapt and influence the sustainability of local and global systems. The validation method for this instrument considered four stages: i) Expert judgment: considering the opinions of six educators and experts in information and communication technologies (ICT); ii) a pilot test: that included a non-probabilistic sample of 472 subjects; iii) a principal components analysis (PCA); and iv) a confirmatory factor analysis (CFA). The Questionnaire on Work Habits and Learning for Professional Futures and the Context Questionnaire SIMCE TIC were used as a reference. When performing a psychometric analysis, a Cronbach alpha coefficient of 0.89 was obtained. This confirms that the adaptation of the instrument is good. The results of the dimensional analysis help us define a structure for the new instrument considering three components that explain 55% of the total variance. The results of the confirmatory factor analysis showed adjustment indexes that support the theoretical model proposed for the PLE study. In conclusion, the instrument was composed of three latent variables: Open self-regulated learning (OSRL) with eight questions, information management (IM) with four questions, and creation and transfer of knowledge (CTK) with four questions.