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- The volunteer functions inventory (VFI): Adaptation and psychometric properties among a portuguese sample of volunteersPublication . Martins, Cátia; da Silva, José Tomás; Jesus, Saúl; Ribeiro, Conceição; Estêvão, M. Dulce; Baptista, Ricardo; Carmo, Cláudia; Brás, Marta; Santos, Rita; Nunes, C.: The Volunteer Functions Inventory (VFI) is an instrument widely used to assess volunteers’ motivation based on the Functionalist Model of Omoto and Snyder. It assesses six factors that reflect several motivational functions. The VFI has been translated into various languages and validated in different cultural contexts, but some studies have reported different factor structures (e.g., five or four factors). In the Portuguese context, previous studies have also shown inconsistent results. The aim of this study was to adapt and validate the VFI for Portuguese volunteers, testing several alternative models (nine models) using confirmatory factor analysis. The sample comprised 468 volunteers (76.3% women), aged from 13 to 81 years (M = 36.66, SD = 14.93). The results support the original interrelated six-factor model as the best-fitting one. The VFI showed good internal consistency and convergent validity. Significant correlations were found between the VFI factors, organizational commitment, and volunteers’ satisfaction. Overall, the six-factor VFI is a valid and reliable tool for measuring the motivational functions of Portuguese volunteers, with implications for practice and research in the volunteering field.
- Forecasting air pollutants using classification models: a case study in the Bay of Algeciras (Spain)Publication . Rodríguez-García, M. I.; Ribeiro, Conceição; González-Enrique, J.; Ruiz-Aguilar, J. J.; Turias, I. J.The main goal of this work is to obtain reliable predictions of pollutant concentrations related to maritime traffic (SO2, PM10, NO2, NOX, and NO) in the Bay of Algeciras, located in Andalusia, the south of Spain. Furthermore, the objective is to predict future air quality levels of the principal maritime traffic-related pollutants in the Bay of Algeciras as a function of the rest of the pollutants, the meteorological variables, and vessel data. In this sense, three scenarios were analysed for comparison, namely Alcornocales Park and the cities of La Linea and Algeciras. A database of hourly records of air pollution immissions, meteorological measurements in the Bay of Algeciras region and a database of maritime traffic in the port of Algeciras during the years 2017 to 2019 were used. A resampling procedure using a five-fold cross-validation procedure to assure the generalisation capabilities of the tested models was designed to compute the pollutant predictions with different classification models and also with artificial neural networks using different numbers of hidden layers and units. This procedure enabled appropriate and reliable multiple comparisons among the tested models and facilitated the selection of a set of top-performing prediction models. The models have been compared using several quality classification indexes such as sensitivity, specificity, accuracy, and precision. The distance (d(1)) to the perfect classifier (1, 1, 1, 1) was also used as a discriminant feature, which allowed for the selection of the best models. Concerning the number of variables, an analysis was conducted to identify the most relevant ones for each pollutant. This approach aimed to obtain models with fewer inputs, facilitating the design of an optimised monitoring network. These more compact models have proven to be the optimal choice in many cases. The obtained sensitivities in the best models were 0.98 for SO2, 0.97 for PM10, 0.82 for NO2 and NOX, and 0.83 for NO. These results demonstrate the potential of the models to forecast air pollution in a port city or a complex scenario and to be used by citizens and authorities to prevent exposure to pollutants and to make decisions concerning air quality.
- The Volunteer Motivation Scale (VMS): Adaptation and psychometric properties among a Portuguese Sample of VolunteersPublication . Martins, Cátia; Jesus, Saúl; da Silva, José Tomás; Ribeiro, Conceição; Estêvão, M. Dulce; Mocho, Helena; Ratinho, Elias; Nunes, C.Using self-determination theory, this study examined the autonomous motivation and regulatory styles of volunteers. The Volunteer Motivation Scale (VMS) is one of the main instruments available to assess these constructs, but it requires validation and adaptation for different contexts. Therefore, the goal of this study was to analyze the psychometric properties of the 12-item VMS in a sample of Portuguese volunteers. The sample consisted of 207 volunteers, mostly women (74.4%), aged from 14 to 81 years, from various areas of volunteering. The measures included self-regulation, basic psychological needs, causality orientation, and autonomy support. Confirmatory factor analysis using the lavaan package in R was performed to test a four-factor model and a two-factor model. The results indicated that the four-factor model had a better fit to the data. The VMS showed good internal consistency, discriminant validity, and convergent validity. The VMS can be viewed as a valuable tool for professionals and a promising avenue for future research on the motivations of volunteers.
- Air pollution PM10 forecasting maps in the maritime area of the Bay of Algeciras (Spain)Publication . Rodríguez-García, María Inmaculada; Carrasco-García, María Gema; Ribeiro, Conceição; González-Enrique, Javier; Ruiz-Aguilar, Juan Jesús; Turias, Ignacio J.Predicting the levels of a pollutant in a given area is an open problem, mainly because historical data are typically available at certain locations, where monitoring stations are located, but not at all locations in the area. This work presents an approach based on developing predictions at each of the points where an immission station is available; in this case, based on shallow Artificial Neural Networks, ANNs, and then using a simple geostatistical interpolation algorithm (Inverse Distance Weighted, IDW), a pollutant map is constructed over the entire study area, thus providing predictions at each point in the plane. The ANN models are designed to make 1 h ahead and 4 h ahead predictions, using an autoregressive scheme as inputs (in the case of 4 h ahead as a jumping strategy). The results are then compared using the Friedman and Bonferroni tests to select the best model at each location, and predictions are made with all the best models. In general, to the 1 h ahead prediction models, the optimal models typically have fewer neurons and require minimal historical data. For instance, the best model in Algeciras has an R of almost 0.89 and consists of 1 hidden neuron and 3 to 5 lags, similar to Colégio Los Barrios. In the case of 4h ahead prediction, Colégio Carteya station shows the best model, with an R of almost 0.89 and a MSE of less than 240, including 5 hidden neurons and different lags from the past. The results are sufficiently adequate, especially in the case of predictions 4 h into the future. The aim is to integrate the models into a tool for citizens and administrations to make decisions.
- Smart travel planning to the Algarve by older tourists before the Covid-19 pandemic crisisPublication . Ribeiro, Conceição; Rocha Silva, Carolina; Serdeira Azevedo, Paula; Pires Rosa, ManuelaInformation and communication technologies, or ICT, have revolutionized societies' daily lives and the economy's development on a global scale. Senior tourism is considered a sector in solid expansion, and, as such, it matters to understand the importance that these tourists attribute to these technologies. The association between tourism and digitalization gave rise to the concept of "smart tourism". So, it is essential to have the necessary skills to be active in a world mediated by the internet. It is not just tourist destinations that have evolved in the present digital age; tourists, themselves, have also changed. However, this digitalization has not equitably reached the entire senior population. The main goal of this article is to analyze the internet use by older tourists to plan their trip to the Algarve before the COVID-19 pandemic crisis. It has the specific objective of identifying and exploring what type of service they sought the information. The results indicate that there are statistically significant differences between different groups of respondents regarding the use of the internet to plan a trip to the Algarve.
- The Volunteer Satisfaction Survey (VSS): adaptation and psychometric properties among Portuguese VolunteersPublication . Martins, Cátia; De jesus, Saúl; da Silva, José Tomás; Ribeiro, Conceição; Nunes, C.; Ferreira Cunha, Francisca; Marcelo, Beatriz(1) Background: Volunteering satisfaction is one significant construct that nourishes the sustaining of volunteer work, and it is present in reference models such as the three-stage volunteer process model (VPM). The volunteer satisfaction survey (VSS), created by Vecina, Chacón and Sueiro, evaluates three different domains of volunteer satisfaction: specific motivations, organization management and volunteering tasks. The aim of this study was to adapt the instrument and explore the psychometric properties of the 17 items of the VSS in a sample of Portuguese volunteers. (2) Methods: The sample was composed of 335 Portuguese volunteers (aged between 14 and 81 years), mainly women (76.4%). Measures included volunteer satisfaction, work engagement and organizational commitment. (3) Results: The original three-factor model was tested with a confirmatory factor analysis (CFA) and the model fitted the data. Satisfactory levels of internal consistency, discriminant and convergent validity were found. (4) Conclusions: The VSS reveals good psychometric properties and can be considered a useful tool for professionals and future research for volunteers’ satisfaction assessment.
- The volunteer functions inventory (VFI): adaptation and psychometric properties among a portuguese sample of volunteersPublication . Martins, Cátia; Silva, José Tomás da; Neves de Jesus, Saúl; Ribeiro, Conceição; Estêvão, Maria Dulce da Mota Antunes de Oliveira ; Baptista, Ricardo; Carmo, Cláudia; Brás, Marta; Santos, Rita; Nunes, CristinaThe Volunteer Functions Inventory (VFI) is an instrument widely used to assess volunteers’ motivation based on the Functionalist Model of Omoto and Snyder. It assesses six factors that reflect several motivational functions. The VFI has been translated into various languages and validated in different cultural contexts, but some studies have reported different factor structures (e.g., five or four factors). In the Portuguese context, previous studies have also shown inconsistent results. The aim of this study was to adapt and validate the VFI for Portuguese volunteers, testing several alternative models (nine models) using confirmatory factor analysis. The sample comprised 468 volunteers (76.3% women), aged from 13 to 81 years (M = 36.66, SD = 14.93). The results support the original interrelated six-factor model as the best-fitting one. The VFI showed good internal consistency and convergent validity. Significant correlations were found between the VFI factors, organizational commitment, and volunteers’ satisfaction. Overall, the six-factor VFI is a valid and reliable tool for measuring the motivational functions of Portuguese volunteers, with implications for practice and research in the volunteering field.