Boundary tracking and source seeking of oceanic features using autonomous vehicles

The thesis concerns the study and the development of boundary tracking and source seeking approaches for autonomous vehicles, specifically for marine autonomous systems. The underlying idea is that the characterization of most environmental features can be posed from either a boundary tracking or a source seeking perspective. The suboptimal sliding mode boundary tracking approach is considered and, as a first contribution, it is extended to the study of three dimensional features. The approach is aimed at controlling the movement of an underwater glider tracking a three-dimensional underwater feature and it is validated in a simulated environment. Subsequently, a source seeking approach based on sliding mode extremum seeking ideas is proposed. This approach is developed for the application to a single surface autonomous vehicle, seeking the source of a static or dynamic two dimensional spatial field. A sufficient condition which guarantees the finite time convergence to a neighbourhood of the source is introduced. Furthermore, a probabilistic learning boundary tracking approach is proposed, aimed at exploiting the available preliminary information relating to the spatial phenomenon of interest in the control strategy. As an additional contribution, the sliding mode boundary tracking approach is experimentally validated in a set of sea-trials with the deployment of a surface autonomous vehicle. Finally, an embedded system implementing the proposed boundary tracking strategy is developed for future installation on board of the autonomous vehicle. This work demonstrates the possibility to perform boundary tracking with a fully autonomous vehicle and to operate marine autonomous systems without remote control or pre-planning. Conclusions are drawn from the results of the research presented in this thesis and directions for future work are identified

Second order sliding mode observers for fault reconstruction in power networks

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This paper proposes a 2-sliding mode observer to detect and reconstruct a certain class of load altering faults in a power network. The observer design is based on the recently proposed multivariable super-twisting structure. The IEEE benchmark power networks used to test the scheme are modelled as a semi-explicit class of differential algebraic equations (DAEs). For the purpose of developing the detection scheme, only the phase angles of the generators are measured, which represent a subset of the differential states of the DAEs. The objective is to estimate the differential states (the phase angles and frequencies of the generators), the algebraic states (the phase angles of the load bus tensions) and to reconstruct a class of load altering faults affecting the network. The proposed observer is assessed in simulation on two IEEE benchmarks: the 9-bus and 14-bus networks, so as to verify its capability to correctly estimate the differential and algebraic states of the network in spite of its complexity and uncertainty. Moreover, the capability of the proposed scheme to detect the presence of a load altering fault, to exactly identify its position in the network, and to precisely reconstruct the shape of the fault itself is shown and discussed

Environmental feature exploration with a single autonomous vehicle

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this record.In this paper, a sliding mode based guidance strategy is proposed for the control of an autonomous vehicle. The aim of the autonomous vehicle deployment is the study of unknown environmental spatial features. The proposed approach allows the solution of both boundary tracking and source seeking problems with a single autonomous vehicle capable of sensing the value of the spatial field at its position. The movement of the vehicle is controlled through the proposed guidance strategy, which is designed on the basis of the collected measurements without the necessity of pre-planning or human intervention. Moreover, no a priori knowledge about the field and its gradient is required. The proposed strategy is based on the so-called sub-optimal sliding mode controller. The guidance strategy is demonstrated by computer based simulations and a set of boundary tracking experimental sea trials. The efficacy of the algorithm to autonomously steer the C-Enduro surface vehicle to follow a fixed depth contour in a dynamic coastal region is demonstrated by the results from the trial described in this paper.Natural Environment Research Council (NERC)Defence Science and Technology Laboratory (DSTL)Innovate UKAutonomous Surface Vehicles (ASV) Ltd., Portcheste

Homeschooling and the criticism of school: hybridisms and educational (dis)continuities

Desde os anos 1960, o homeschooling apresenta dinâmicas de crescimento atualizadas nos diagnósticos da crise do capitalismo e dos sistemas educativos. Por ser praticado por famílias próximas do progressismo libertário, do cristianismo conservador ou de outras inspirações axiológicas, a abordagem investigativa presente neste texto pressupôs romper com uma visão unívoca e alheia à sua diversidade e aos diferentes graus de (in)formalidade dos quotidianos educativos de crianças e de jovens que caracterizam este fenómeno educativo. Procura-se captar as especificidades do ensino doméstico (ED) em Portugal e a sua crescente expressão social e educacional e reflete-se sobre os sentidos das aprendizagens que ele encerra. Conclui-se que o ED parece ser contrário aos horizontes formativos da criança segundo o interesse da sociedade, sendo omisso sobre o seu papel na emancipação dos sujeitos. Confrontam-se a escola e o seu modo de funcionamento a partir do racional do ED, à procura de novas epistemologias e de novas linhas de pesquisa.Since the 1960s, homeschooling has shown growth dynamics updated by the diagnosis of the crisis of capitalism and of educational systems. Because it is practiced by families close to libertarian progressivism, conservative Christianity, or other axiological inspirations, this paper’s approach sought to break with a univocal conception alien to its diversity and to the different degrees of (in)formality of the children’s and young people’s educational daily lives inherent to this educational practice. Therefore, this paper seeks to understand the specificities of Portuguese homeschooling and its increasing social and educational expression, and to reflect on the meanings of the learning it entails. Being unclear about its role on the emancipation of the subjects, homeschooling seems to be contrary to the educational horizons of the child according to the interests of the whole society. This paper confronts school and its way of functioning with the homeschooling rationale in order to search for new epistemologies and new lines of research.info:eu-repo/semantics/publishedVersio

Evaluation of emotional intelligence among master\u2019s degree students in nursing and midwifery: A cross-sectional survey

Emotional intelligence is an important skill for nurses and midwives and leads them to cleverly work in various fields and contexts, successfully handling colleagues, patients and their families. The aim of this cross-sectional study is to evaluate the relationship between emotional intelligence, sociodemographic and academic variables in current and former master\u2019s degree students in nursing and midwifery, through the administration of a questionnaire to 71 subjects. Emotional intelligence is significantly related to gender. Females showed higher scores (0.2 points higher than men) for emotional intelligence factors, highlighting an excellent ability to \u201cevaluate and express emotions in relation to others\u201d. Moreover, significant differences in academic performances are shown: both females and midwives demonstrated higher academic performance (a mean degree mark 3.8 points higher than men and a mean degree mark 2.6 point than nurses, respectively). High levels of emotional intelligence in individuals who carried out training activities in the organization area are also evident: these subjects have an ability regarding the \u201cregulation of emotion in the others\u201d, which is significantly higher (p = 0.01) than those interested in other master\u2019s degree areas. Emotional intelligence (EI) is strongly linked to the individual\u2019s characteristics and their personalities and differs from technical and professional skills. EI is also an excellent predictor of professional success

Vaccine hesitancy among master\u2019s degree students in nursing and midwifery: Attitude and knowledge about influenza vaccination

Influenza vaccination among healthcare workers may reduce morbidity and protect fragile patients. Most of the evidence concerning the vaccine hesitancy of healthcare workers reported lack of knowledge and wrong attitude. The aims of this study were to explore the knowledge and attitudes about influenza vaccination among master\u2019s degree students in Nursing and Midwifery, and to evaluate the effectiveness of their involvement in the hospital vaccination campaign in order to increase intention to receive immunization. The students of nurses and midwives were involved in the vaccination sessions of the 2018\u201319 hospital campaign. They were recruited to complete an online survey. Students of the 2nd year (involved in the vaccination campaign) and the 1st year (not involved) were compared. Descriptive and inferential statistics were performed for data analysis. Students who intend to receive influenza vaccination in the following year registered a percentage of 83.6% and showed an overall attitude of 66.8%. The involvement of the students in the vaccination campaign led to a significant increase in their positive vaccination attitude (80.9% vs. 87.0%) and in their intention to receive flu vaccination in the following year (67.7% vs. 100%). A positive attitude towards vaccinations was observed by nurses and midwives. Their involvement in the planning and activities during the vaccination campaign could positively influence their opinions and intention to receive vaccination

Improving nursing staff attitudes toward vaccinations through academic detailing: The hproimmune questionnaire as a tool for medical management

Vaccinations remain the most effective way of preventing infection, disease, and mortality. Public health institutions consequently recommend vaccines to target groups, including healthcare workers, who are considered to be more at risk of exposure and transmission. The aim of this cross-sectional study is to assess, through the administration of a questionnaire, the nursing staff\u2019s knowledge and attitude towards recommended vaccinations, and to explore the effects of a training course (carried out according to the academic detailing methodology) aimed at increasing operators\u2019 knowledge and outreach on recommended vaccinations among healthcare workers. A total of 85 HCWs (30 nursing coordinators and 55 nurses) completed the questionnaire. Results demonstrate a higher rate of agreement towards vaccinations in nursing staff answers (75%), if compared with results of other studies (62\u201363%). Statistically significant differences between nursing coordinators and nurses can be found. Regarding vaccination attitudes, nursing coordinators agreed in 86% of the answers on healthcare workers\u2019 vaccination vs 70% of nurses (p < 0.001). Considering immunization for influenza, 57% of nursing coordinators vs 18% of nurses reported for vaccination (p < 0.001). Educational programs, carried out according to academic detailing methods, could impact on vaccination attitudes and raise awareness about recommended vaccinations among healthcare workers. The questionnaire is a useful tool for investigating nursing staff knowledge and attitudes towards vaccinations, and to implement strategies to promoting vaccinations among healthcare workers

Can Prefigurative Politics Prevail? The Implications for Movement Strategy in John Holloway’s Crack Capitalism.

The desire to overcome the alienated labor of capitalism manifests itself in the daily actions of people everywhere. John Holloway argues that social movements must build upon this liberatory impulse, challenging not only the rate of exploitation but also workers\u27 loss of control over the process of production and allocation (and, by implication, the loss of control in other arenas of life). Revolutionary change, in turn, will result from these movements creating thousands of \u27cracks\u27 in the capitalist system by asserting alternative ways of living. Holloway\u27s argument for prefigurative movements is ambiguous on several points, however: the role of political orgnaizations, the role of alternative institutions, and the appropriate approach of social movements to the state. We propose some friendly amendments, placing great emphasis on the need for strong political organizations and counter-institutions, but also for selective engagement with dominant institutions. A revolutionary strategy must combine the construction of prefigurative counter-institutions with struggles for reform of existing structures.Yet the dangers of oligarchization and hierarchy within movements are very real, and thus there is a need for structures that are ruthlessly democratic and ideologies that are explicitly intersectional in their approach to fighting different forms of oppression