Abstract
This article presents a literature review and the discussion about the key concepts associated with data markets. Data markets have multiple centralized and decentralized approaches. The main problem is the trust and reliability of supplies, inflows, and suppliers. The proposed study object is the decentralized marketplace data supported by Blockchain technology to ensure confidence in the supply chain of data, in the actors involved in the market and the data sources. The application scenarios are proposed in a model with four levels, data provision, data delivery, rights management, and producer internal sources. That will be done with Blockchain technology, through contracting using smart contracts, the controlled delivery of data by the data producers, the management of flows of data, and access control to data. © 2019, Springer Nature Switzerland AG.

Abstract
Today’s society presents a fast development marked by the digital era, where the sharing, disclosure and access to information is made through information and communication technologies. The use of mobile applications is growing exponentially, spreading to the most varied social classes and everyday activity areas. Worldwide, its use in the most variety of services, has been increasing significantly. Given that, it is essential that mobile applications are accessible in a way that allows access conditions and equal opportunities to all the users. With this study we present indicators regarding the state of accessibility in mobile applications through the evaluation of five Portuguese public administration applications. The methodology used was a fully manual evaluation through a proposal of a model of evaluation divided by quantitative and qualitative requirements created by us, as well as the use of functionalities such as VoiceOver and TalkBack. Taking into account that the study initially proposed on accessibility in mobile applications is the first to be carried out in Portugal and one of the few currently worldwide, it is believed that its content may help, in some way, to raise awareness of the state of accessibility in the Portuguese mobile applications, to create measures that make these applications more accessible to all and that this work could be taken into account in future studies of the topic. © 2019, Springer Nature Switzerland AG.

Abstract
The Internet of Things (IoT) is rapidly becoming ubiquitous and applied in different domains such as human health, building automation, industrial control and environmental monitoring, introducing new security and privacy challenges. Thus, the security of data, devices and communications of IoT networks are a concern due to the sensitivity of the data used, legal and privacy issues, and the diversity of devices and protocols used. In addition, traditional security mechanisms cannot always be feasible and adequate because of the number, heterogeneity, and resource limitations of IoT devices. In this work, we are concerned with the design of an Intrusion Detection System (IDS) to protect IoT networks from external and internal threats in real time. To do this, after studying the various traditional IDS solutions, as well as new IDS proposals designed specifically for IoT networks, we conclude that there are still several improvements to be made to this type of 2nd line defense mechanism. The design proposed will consider the specific architecture of an IoT network, the scalability and heterogeneity of this type of environment, the minimization of the use of resources, and the maximization of the efficiency in the detection of intrusions. To do so, we consider the various detection methods available and the various types of attacks to which this type of network is exposed. The proposed IDS is network-based and relies on a hybrid architecture (centralized / distributed). As methods of detection, the signature / anomaly-based methods will be used simultaneously. Finally, it is emphasized that this proposal does not require the modification of the IoT software, nor does it influence the performance of the applications in the IoT devices.

Abstract
It is undeniable that the world is taking a turn for the digital. Banking, shopping, working, education, entertainment, everything has its own digital equivalent or means thereof. This includes language learning. Nowadays, there is a myriad of (mobile and digital) possibilities to study, learn and improve a person’s knowledge of virtually any language. Thus, there should be potential benefits in their use in academic level (foreign) language learning, but also in an individual “self-learning" process. In this study, we choose to tackle mobile apps and their impact in the teaching/learning of languages, the perception of their usefulness and their impact (positive or otherwise) on the subject. To achieve this, a literature review on the subject was conducted, in addition to twenty interviews performed with students of the University of Aveiro. Supported by our literature review, we can safely state that language learning is just one of the many segments of both life and academia that can only be positively affected by digitalisation, and that we will continue seeing a rising trend towards that goal. © Springer Nature Switzerland AG 2019.

Abstract

Abstract
Nowadays, workers and students preparing for a career are aware that they must constantly update their skills in order to fulfil both the market’s and companies’ demands. The environment is packed with technologies that help us by optimizing our tasks on a daily basis. However, the majority of opinions can agree that these tools may have a bigger impact on the labour market than it was ever expected. What is the future of jobs as we know them, and what impact will future technology innovations have on society? Lots of factors enter the picture when this particular topic is discussed – including the economy in general, productivity rates, salaries and expenses, people’s stress and satisfaction levels, among others. To achieve this study’s main purpose, questionnaires were distributed, which were the basis for the creation of a hypothetical model that represents our understanding of the subject considering the sample’s feedback. This study also advances our view concerning the literature review and the opinions of those surveyed, aiming to provide a strong and consistent theory of what the market labour will be; that is, which jobs are likely to lose practice, which ones may subsist, and which activities might grow with the circumstances’ influence. © 2019, Springer Nature Switzerland AG.