Interactive computational modelling to improve teaching of physics and mathematics in marine geophysics

This study discusses the implementation of a learning sequence with interactive computational modelling activities in the context of introductory marine geophysics university courses. The application of two computer modelling systems, Modellus and Mirone, is considered for the introduction of mathematical physics models of interest in marine geophysics to students having only basic level knowledge of physics and mathematics and no prior knowledge of scientific computation. Modellus is used to compute the theoretical depth of the seafloor predicted using the plate cooling model, while is used to manipulate and display actual bathymetric data in the region of mid-ocean ridges. The combination of both software systems is illustrative and insightful of functionalities suitable to develop other computational modelling activities for marine geophysics as well as for other areas of the geosciences.FCT-projects [UID/GEO/50019/2019, UID/CED/02861/2019]info:eu-repo/semantics/publishedVersio

Liderança, satisfação e perceção de rendimento desportivo: estudo com atletas seniores

Este estudo analisa a relação entre os estilos de liderança dos treinadores (tomada de decisão, transacional e transformacional), o modo como os atletas avaliam a liderança dos treinadores (e.g., satisfação com a liderança) e o modo como percecionam o rendimento desportivo ao nível individual e coletivo. Esta análise considerou a importância de variáveis pessoais (e.g., sexo) e desportivas (e.g., divisão competitiva, anos de trabalho com atual treinador e títulos desportivos obtidos com atual treinador) dos atletas. Participaram no estudo 313 atletas de diferentes modalidades com média de idades de 23 anos. Avaliou-se a perceção dos atletas em relação à liderança do treinador, a satisfação face à liderança e a perceção de obtenção de objetivos de rendimento desportivo. Os resultados demonstraram que as dimensões de liderança transformacional foram importantes na explicação da satisfação dos atletas com a liderança dos treinadores bem como na explicação da perceção de rendimento desportivo. As dimensões de liderança foram também importantes para explicar o tempo de permanência dos treinadores na orientação das respetivas equipas bem como o sucesso desportivo obtidos pelos atletas com o mesmo treinador. Em suma, as três formas de liderança revelaram-se importantes para explicar o modo como os atletas avaliam a atividade desportiva.This study analyses the relationship between coaches’ leadership styles (such as decision making, transactional and transformational), athletes’ evaluation of the leadership of their coaches (e.g., satisfaction with leadership) and how athletes evaluate their sport performance both at individual and team levels. This analysis considered the importance of athletes’ personal variables (e.g., gender) and athletes’ sports variables (e.g., competitive level, years of work with current coach and sports titles achieved with current coach). Thus, the study included 313 athletes with an average age of 23 years, practicing different types of sports. It was evaluated the athletes’ perception of coaches’ leadership, the athletes’ satisfaction towards leadership, and the athletes’ perception of sports performance, at individual and team levels. Our findings suggest that transformational leadership dimensions are fundamental to explain athletes’ satisfaction regarding the coaches’ leadership and their perception of sports performance. In addition, leadership variables also explain how long coaches and athletes have been working together and how many sport titles have been won within such timeframe. In sum, the three styles of leadership proved to be decisive to explain how athletes evaluate their sporting activity.Este estudo foi realizado em parte no Centro de Investigação em Psicologia (UID/PSI/01662/2013), Universidade do Minho, e foi financeiramente suportado pela Fundação para a Ciência e Tecnologia e pelo Ministérios da Ciência, Tecnologia e Ensino Superior, através de fundos nacionais, e cofinanciado pelo FEDER, através do COMPETE2020, no âmbito do acordo Portugal 2020 (POCI-01-0145-FEDER-007653)

Assessing psychache as a suicide risk variable: Data with the Portuguese version of the psychache scale

Several studies have consistently related psychological pain to suicide risk. Psychache, according to Shneidman's perspective and measured by the Psychache Scale has been confirmed as an important variable in risk prediction. In the present study, we evaluated psychache as a construct related to suicide risk using data obtained with the Portuguese version of the Psychache Scale translated from the original English version. A community sample of 628 individuals responded to the Portuguese version of the Psychache Scale, the Suicidal Behavior Questionnaire-Revised, the CES-D Scale, the Beck Hopelessness Scale, and the Suicide Ideation Questionnaire. Results supported the unidimensional scoring of the Psychache scale, its ability to differentiate between individuals at-risk for suicide from individuals not at-risk, its relationship with different, but related, constructs and its ability to predict suicide ideation

Occupational stress and cognitive appraisal profiles as predictors of students’ burnout

Objective: Analyze if different patterns of occupational stress experienced by students (lower versus higher) and different cognitive appraisal profiles assumed by students (positive evaluation of academic activity versus negative evaluation of academic activity) affect their experience of burnout over time. Background: The interactive and transactional perspective of adaptation to stress was adopted to analyze how university students evaluate their activity and related academic stress, and how they feel in terms of burnout. Method: Longitudinal study design, with three moments of data collection, with a sample of 175 psychology students, from a Portuguese university. The investigation protocol included the Stress Questionnaire for Students, the Primary and Secondary Cognitive Appraisal Scale, and the Shirom-Melamed Burnout Scale. Results: The results showed that students who experienced higher levels of stress and a negative evaluation of their academic activity also reported higher levels of burnout when compared to students who experienced lower levels of stress and positive evaluation of academic activity. Moreover, a pattern of high stress in M1 increases in 443% the probability to experience moderate to high burnout in M2. A profile of negative evaluation of the academic activity in M1 increases in 594% the probability to experience high burnout in M2. Students exposed to high levels of burnout at M2 are over nine times more likely to experience moderate levels of burnout at M3, and over 300 times more likely to experience high levels of burnout at M3. Conclusion: Students who experience higher academic stress and those who evaluate their academic activity more negatively have a higher tendency to experience burnout. Although, the experience of burnout in a specific data point is the main predictor of experiencing burnout in a later moment, highlighting the chronic effects of this syndrome on human wellbeing. Application: This study provides specific indications of how much stress and cognitive appraisal can affect burnout, alerting also for the chronic nature of burnout feelings, which must be considered in safety and occupational health interventions.This study was conducted at the Psychology Research Centre (CIPsi/UM) School of Psychology, University of Minho, supported by the Foundation for Science and Technology (FCT) through the Portuguese State Budget (UIDB/01662/2020)

A theoretical approach of adaptation to stress and implications for evaluation and research

[Excerpt] The study of adaptation to occupational stress is a major topic of research on psychology, and other social sciences. In fact, data suggests that employees face significant levels of tension at work, and that there is an increasing of sources of stress, both in terms of intensity and diversity [1]. In this chapter, we analyze adaptation to stress by focusing at the individual level, discussing how professionals evaluate and cope with stressors that impose significant efforts of adjusting. However, this does not mean that occupational stress is strictly an individual phenomenon; by the contrary, a better understanding of stress at work should assume a multifactor perspective, where the employee, the employer, the work organization, the public policies and laws of work, and the cultural values and norms that influence professional relations between all these agents, play together and determine if the working activity will be a pleasant or dysfunctional experience for professionals. Despite the importance of considering all these factors when studying the working activity, it is also obvious that the way each worker adapt to their working conditions is a pivotal factor to understand how this activity can represent a source of personal gratification or, by the contrary, can ended represent a negative, or even indifferent, experience. [...]info:eu-repo/semantics/publishedVersio

Work–family conflicts, cognitive appraisal, and burnout: testing the mediation effect with structural equation modelling

Work-family conflict constitutes an important source of occupational stress predicting teachers’ burnout, and cognitive variables have shown to be core structures in explaining human adaptation to stress. Nevertheless, the role of cognitive appraisal needs to be fully analysed to comprehend how it can mediate the relationship between stress and burnout. In order to understand the potential mediation of cognitive appraisal in the relationship between stress and burnout, we adopted conceptual models of stress that highlighted the value of cognitive appraisal on positive and negative reactions to work demands. Also, we analysed the potential moderation of sex and age in the relationship between work-family conflict, cognitive appraisal, and burnout due inconsistent findings on how these personal variables can interfere on these relations. In this study, we used Structural Equation Modelling (SEM) to test the mediating of cognitive appraisal in the relationship between work-family conflicts and burnout. A survey with measures of work-family conflicts, cognitive appraisal, and burnout was administered to the participants consisting of 438 Portuguese teachers from kindergarten through high school, aged between 28 and 67 years (M = 46.85; SD = 7.88), 304 of whom were females (69.41%). The results confirmed that cognitive appraisal partially mediated the relationship between work-family conflict and burnout. The mediation effect of cognitive appraisal on the relationship between work-family conflict and burnout was invariant regardless of teachers’ sex or age. In sum, cognitive appraisal should be considered in order to understand teachers’ adaptation to work.This study was conducted at the Psychology Research Centre (PSI/01662), School of Psychology, University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education (UID/PSI/01662/2019), through the national funds (PIDDAC). The authors have no conflicts of interest to report

Low-Complexity Equalisers for Offset Constellations in Massive MIMO Schemes

This work was supported in part by the European Regional Development Fund (FEDER), through the Competitiveness and Internationalization Operational Program of the Portugal 2020 Framework, in part by the Regional OP Centro under Grant POCI-01-0145-FEDER-030588, in part by the Regional OP Lisboa under Grant Lisboa-01-0145-FEDER-03058, in part by the FCT/MEC through national funds of MASSIVE5G Project under Grant SAICT-45-2017-02 and PES3N Project under Grant 2018-SAICT-45-2017-POCI-01-0145-FEDER-030629, in part by the UID/EEE/50008/2019 Project, and in part by the FCT Ph.D. under Grant SFRH/BD/108522/2015.Massive multi-input-multi-output (m-MIMO) schemes require low-complexity implementations at both the transmitter and the receiver side, especially for systems operation at millimeter wave (mmWave) bands. In this paper, we consider the use of offset constellations in m-MIMO systems operating at mmWave frequencies. These signals are designed to have either an almost constant envelope or be decomposed as the sum of constant-envelope signals, making them compatible with strongly nonlinear power amplifiers, which can have low-implementation complexity and high amplification efficient, making them particularly interesting for mmWave communications. We design and evaluate low-complexity frequency-domain receivers for offset signals. It is shown that the proposed receivers can have excellent performance/complexity trade-offs in m-MIMO scenarios, making them particularly interesting for future wireless systems operating at mmWave bands.publishersversionpublishe

Detecting parametric resonance in a floating oscillating water column device for wave energy conversion: Numerical simulations and validation with physical model tests

The wave energy sector has faced enormous technological improvements over the last five decades, however, due to the complexity of the hydrodynamic processes, current numerical models still have limitations in predicting relevant phenomena. In particular, floating spar-type wave energy converters are prone to large undesirable roll and pitch amplitudes caused by a dynamic instability induced by parametric resonance. Detecting this phenomenon accurately is essential as it impacts drastically on power extraction, structural loads and mooring forces. This paper presents the validation of results from a numerical model, capable of detecting parametric resonance, using experimental data. Experiments were carried out for a scaled model of the Spar-buoy OWC (Oscillating Water Column) device at a large ocean basin. The buoy uses a slack-mooring system attached to the basin floor. The scaled turbine damping effect is simulated by a calibrated orifice plate. Two different buoy draft configurations are considered to analyse the effect of different mass distributions. The numerical model considers the nonlinear Froude-Krylov forces, which allows it to capture complex hydrodynamic phenomena associated with the six-degree-of-freedom motion of the buoy. The mooring system is simulated through a quasi-static inelastic line model. Real fluid effects are accounted for through drag forces based on the Morison’s equation and determined from experimental data. The comparison of results from regular-wave tests shows good agreement, including when parametric resonance is detected. Numerical results show that parametric resonance can produce a negative impact on power extraction efficiency up to 53%

Retrofit measures evaluation considering thermal comfort using building energy simulation: two Lisbon households

ABSTRACT: Retrofit measures for buildings are in general evaluated considering the energy savings and life cycle cost. However, one of the main benefits, the increase of users comfort is very seldom analysed. In this work, two residential households representative of a large share of households in Portugal, were monitored and its thermal behavior was modeled using Energy Plus. The thermal evaluation of the pre-retrofit households shows that the winter season is problematic due to construction solutions and low availability for heating. The retrofit measures analysis was performed considering different retrofit solutions regarding envelope improvement and efficient systems implementation. In order to work around the question of comparing households that do not use energy for acclimatization and therefore have very low energy consumption, in the retrofit scenarios it was considered the thermal comfort evaluation value for the real case (pre-retrofit) and compared the energy consumption to achieve that same average comfort level (in this case avoiding high discomfort peaks). The measures that more rapidly pay the investment are those related with implementing active systems. The approach used in this paper, should be used in more calibrated models in order to have overall conclusions about the retrofit process at a larger scale.info:eu-repo/semantics/publishedVersio