Abstract
Mobile applications are increasingly present in our daily lives. Being increasingly dependent on apps, we all want to make sure apps work as expected. One way to increase confidence and quality of software is through testing. However, the existing approaches and tools still do not provide sufficient solutions for testing mobile apps with features different from the ones found in desktop or web applications. In particular, there are guidelines that mobile developers should follow and that may be tested automatically but, as far as we know, there are no tools that are able do it. The iMPAcT tool combines exploration, reverse engineering and testing to check if mobile apps follow best practices to implement specific behavior called UI Patterns. Examples of UI Patterns within this catalog are: orientation, background-foreground, side drawer, tab-scroll, among others. For each of these behaviors (UI Patterns), the iMPAcT tool has a corresponding Test Pattern that checks if the UI Pattern implementation follows the guidelines. This paper presents an extension to iMPAcT tool. It enables to test if Android apps work properly after receiving an incoming call, i.e., if the state of the screen after the call is the same as before getting the call. It formalizes the problem, describes the overall approach, describes the architecture of the tool and reports an experiment performed over 61 public mobile apps.

Abstract

Abstract
The evolution of technology has led to a set of technologies suitable for mobility and ubiquity scenarios. Phenomena of wireless computing, mobile devices and, generally, miniaturized sensors and actuators embedded in physical spaces are a today's reality. This phenomenon has opened the door to a set of opportunities for reengineering the way we perceive a given fact or situation and the way we act on it. Regarding the delivery of information to users of a given physical space, there is now the possibility of transforming the mechanisms of interaction between the space and the user. This change allows the user to see the physical space, that surrounds him, to adapt to himself and to provide him contextualized and personalized information according to his profile of interest. This approach can improve the way we manage customer relationships in a given business context. This paper overview the state of the art of smart spaces and analyses the potential of indoor positioning systems and techniques, and propose a conceptual model for the detection of users in physical spaces and the consequent adaptation of a smart physical space to provide information aligned with the user's profile of interest and according to is privacy rules.

Abstract

Abstract
Low Power Wide Area Networks (LPWAN) enable a growing number of Internet-of-Things (IoT) applications with large geographical coverage, low bit-rate and long lifetime requirements. LoRa (Long Range) is a well-known LPWAN technology which uses a proprietary Chirp Spread Spectrum (CSS) physical layer, while the upper layers are defined by an open standard - LoRaWAN. In this paper, we propose a simple yet effective method to improve the Quality-of-Service (QoS) of LoRa networks by fine-tuning specific radio parameters. Through a Mixed Integer Linear Programming (MILP) problem formulation, we find optimal settings for the Spreading Factor (SF) and Carrier Frequency (CF) radio parameters, considering the network traffic specifications as a whole, to improve the Data Extraction Rate (DER) and to reduce the packet collision rate and the energy consumption in LoRa networks. The effectiveness of the optimization procedure is demonstrated by simulations, considering realistic scenarios. In relation to the traditional LoRa radio parameter assignment policies, our solution leads to an average increase of 30% in DER, and a number of collisions 17 times smaller. In comparison to networks with dynamic radio parameter assignment policies, there is an increase of 10.5% and 4% of DER, and a number of collisions 13.5 and 7.5 times smaller than equal-distribution and random distribution, respectively. Regarding the network energy consumption metric, the proposed optimization obtained an average consumption 3.6 and 2.74 times lower than the equal-distribution and random dynamic allocation policies, respectively. Furthermore, we approach the practical aspects on how to implement and integrate the optimization mechanism proposed in LoRa, guaranteeing backward compatibility with the standard protocol.

Abstract
The hybrid AC/DC microgrids have become considerably popular as they are reliable, accessible and robust. They are utilized for solving environmental, economic, operational and power-related political issues. Having this increased necessity taken into consideration, this paper performs a comprehensive review of the fundamentals of hybrid AC/DC microgrids and describes their components. Mathematical models and valid comparisons among different renewable energy sources' generations are discussed. Subsequently, various operational zones, control and optimization methods, power flow calculations in the presence of uncertainties related to renewable energy sources are reviewed.