Abstract
Topic modeling or inference has been one of the well-known problems in the area of text mining. It deals with the automatic categorisation of words or documents into similarity groups also known as topics. In most of the social media platforms such as Twitter, Instagram, and Facebook, hashtags are used to define the content of posts. Therefore, modelling of hashtags helps in categorising posts as well as analysing user preferences. In this work, we tried to address this problem involving hashtags that stream in real-time. Our approach encompasses graph of hashtags, dynamic sampling and modularity based community detection over the data from a popular social media engagement application. Further, we analysed the topic clusters' structure and quality using empirical experiments. The results unveil latent semantic relations between hashtags and also show frequent hashtags in a cluster. Moreover, in this approach, the words in different languages are treated synonymously. Besides, we also observed top trending topics and correlated clusters.

Abstract
The COVID-19 pandemic has had a significant impact around the world on health, economies, businesses, equality and the movement of people in the form of tourism. In this context, this paper looks at the strategy chosen by Turismo de Portugal to adapt to the crisis in a country where tourism plays an important role in supporting the local economy, having grown significantly since 2010. The chosen strategy encouraged tourists not to visit Portugal during the pandemic, a turnaround from their previous digital marketing strategy, which invited tourists to discover the country. We undertook a survey that had 170 answers, predominantly from Ecuador, Mexico, the United Kingdom and Portugal but also from several other countries in Europe and Latin America. We aimed to understand whether their strategy was successful in encouraging people to consider Portugal as a holiday destination post-COVID-19. The Can't Skip Hope campaign was created in a work-from-home environment, with the voiceover recorded on a smartphone. Previously recorded footage was re-edited. Our survey found that respondents said the video matched their views of Portugal and that 79.5% would consider Portugal as a holiday destination when they next booked a holiday. In terms of inferential statistics, we performed chi-square tests of significance on the survey data. Thus, this paper contributes to the body of work because it offers insight into marketing strategy adaptation by a local tourist board during a period of crisis.

Abstract
Abstract Having accurate and timely data on active COVID-19 cases is challenging, since it depends on the availability of an appropriate infrastructure to perform tests and aggregate their results. In this paper, we consider a case to be active if it is infectious, and we propose methods to estimate the number of active infectious cases of COVID-19 from the official data (of confirmed cases and fatalities) and from public survey data. We show that the latter is a viable option in countries with reduced testing capacity or infrastructures.

Abstract
The increase of the world population and a decrease in agricultural labour availability have motivated research robotics in the agricultural field. This paper aims to analyze the state of the art related to manipulators used in the agricultural robotics field. Two pruning and seven harvesting manipulators were reviewed and are analyzed. The pruning manipulators were used in two different scenarios: (i) grapevines and (ii) apple trees. These manipulators showed that a light-controlled environment could reduce visual errors and that prismatic joints on the manipulator are advantageous to obtain a higher reach. The harvesting manipulators were used for 5 different products: (i) strawberries, (ii) tomatoes, (iii) apples, (iv) sweet-peppers and (v) iceberg lettuce. The harvesting manipulators showed that a different kinematic configuration is required for different end-effectors, as some end-effectors only require horizontal movements and others require more degrees of freedom to reach and grasp the target. This work will support new developments of novel solutions related to agricultural robotic grasping and manipulation.

Abstract
There are several industrial processes that are controlled by a PID or similar controller. In robotics it is also usual the need of position control of joints. Tune a controller is the process to obtain the gains that optimise the behaviour of the system while maintaining its stability and robustness. This paper presents an approach of tuning a speed controller using the Internal Model Control (IMC) method and a position controller using the second order Bessel prototype while testing in different controllers methodology, such as PID, Cascade and feedforward combination with dead zone compensation. In order to compare the controllers, results for an Hermite reference position will allow to validate the proposed solution.

Abstract
Firms aim at achieving their economic interests without neglecting the needs of local and regional communities and the environment itself. The process involves defining and implementing Social Responsibility strategies that leverage organizational competitiveness and sustainability. In this context, the current study purposes to demonstrate how Corporate Social Responsibility (CSR) and a sustainable orientation influence the satisfaction and loyalty of academic tourists to the Metro of Porto (in Portugal). More specifically, our study aims to assess the satisfaction of academic tourists with the Metro of Porto and, additionally, to analyze the variables that determine the satisfaction and loyalty of these tourists to this specific transport company, which has never been achieved before. Our proposed research model seeks to determine how CSR and a sustainable orientation influence academic tourists' loyalty to the Metro of Porto transport services as well as their link to Service Quality, Perceived Value, Corporate Image and Tourist Satisfaction. From a sample of 256 academic tourists, customers of the Metro of Porto, a quantitative analysis was carried out using the structural equation model (SEM-PLS). The results obtained allow us to conclude that CSR and Service Quality have an impact on academic tourists' satisfaction and loyalty to the Metro of Porto. The development of a region is intrinsically linked to transport networks that promote the integration and growth of productive systems. Our results demonstrate the relationship between regional development and business sustainability strategies that integrate Social Responsibility practices. We show the importance that Social Responsibility policies have for companies as a precursor to customer satisfaction and loyalty to a company. Hence, as a guarantee of obtaining economic results, firms must simultaneously contribute to the sustainable development of territories.