2022
Authors
Dias, JP; Restivo, A; Ferreira, HS;
Publication
INTERNET OF THINGS
Abstract
The current complexity of IoT systems and devices is a barrier to reach a healthy ecosystem, mainly due to technological fragmentation and inherent heterogeneity. Meanwhile, the field has scarcely adopted any engineering practices currently employed in other types of large-scale systems. Although many researchers and practitioners are aware of the current state of affairs and strive to address these problems, compromises have been hard to reach, making them settle for sub-optimal solutions. This paper surveys the current state of the art in designing and constructing IoT systems from the software engineering perspective, without overlooking hardware concerns, revealing current trends and research directions.
2022
Authors
Brandao, A; Mendes, R; Vilela, JP;
Publication
CODASPY'22: PROCEEDINGS OF THE TWELVETH ACM CONFERENCE ON DATA AND APPLICATION SECURITY AND PRIVACY
Abstract
Permission managers in mobile devices allow users to control permissions requests, by granting of denying application's access to data and sensors. However, existing managers are ineffective at both protecting and warning users of the privacy risks of their permissions' decisions. Recent research proposes privacy protection mechanisms through user profiles to automate privacy decisions, taking personal privacy preferences into consideration. While promising, these proposals usually resort to a centralized server towards training the automation model, thus requiring users to trust this central entity. In this paper we propose a methodology to build privacy profiles and train neural networks for prediction of privacy decisions, while guaranteeing user privacy, even against a centralized server. Specifically, we resort to privacy-preserving clustering techniques towards building the privacy profiles, that is, the server computes the centroids (profiles) without access to the underlying data. Then, using federated learning, the model to predict permission decisions is learnt in a distributed fashion while all data remains locally in the users' devices. Experiments following our methodology show the feasibility of building a personalized and automated permission manager guaranteeing user privacy, while also reaching a performance comparable to the centralized state of the art, with an F1-score of 0.9.
2022
Authors
Carvalho, M; Lodi, A; Pedroso, JP;
Publication
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
Abstract
The recently-defined class of integer programming games (IPG) models situations where multiple self-interested decision makers interact, with their strategy sets represented by a finite set of linear constraints together with integer requirements. Many real-world problems can suitably be cast in this way, hence anticipating IPG outcomes is of crucial value for policy makers. Nash equilibria have been widely accepted as the solution concept of a game. Thus, their computation provides a reasonable prediction of games outcome. In this paper, we start by showing the computational complexity of deciding the existence of a Nash equilibrium for an IPG. Then, using sufficient conditions for their existence, we develop a general algorithmic approach that is guaranteed to return a Nash equilibrium when the game is finite and to approximate an equilibrium when payoff functions are Lipschitz continuous. We also showcase how our methodology can be changed to determine other types of equilibria. The performance of our methods is analyzed through computational experiments on knapsack, kidney exchange and a competitive lot-sizing games. To the best of our knowledge, this is the first time that equilibria computation methods for general IPGs have been designed and computationally tested.
2022
Authors
Lima, J; Rocha, C; Rocha, L; Costa, P;
Publication
APPLIED SCIENCES-BASEL
Abstract
Counterfeit medicine is still a crucial problem for healthcare systems, having a huge impact in worldwide health and economy. Medicine packages can be traced from the moment of their production until they are delivered to the costumers through the use of Data Matrix codes, unique identifiers that can validate their authenticity. Currently, many practitioners at hospital pharmacies have to manually scan such codes one by one, a very repetitive and burdensome task. In this paper, a system which can simultaneously scan multiple Data Matrix codes and autonomously introduce them into an authentication database is proposed for the Hospital Pharmacy of the Centro Hospitalar de Vila Nova de Gaia/Espinho, E.P.E. Relevant features are its low cost and its seamless integration in their infrastructure. The results of the experiments were encouraging, and with upgrades such as real-time feedback of the code's validation and increased robustness of the hardware system, it is expected that the system can be used as a real support to the pharmacists.
2022
Authors
Kitamura, DT; Rocha, KP; Oliveira, LW; Oliveira, JG; Dias, BH; Soares, TA;
Publication
ELECTRICAL ENGINEERING
Abstract
The continuous proliferation of distributed generation is leading end users to look for new tools that help to design hybrid electrical energy systems (HEES). Thus, this work proposes a novel approach for optimal planning of HEES, which comprises the optimization of the type and capacity of distributed generation connected to the end user. The main objective is to minimize the project's total cost, considering the net metering scheme. To this end, the bioinspired meta-heuristic artificial immune system is proposed to optimally determine the number and type of photovoltaic panels. In addition, a nonlinear programming model is proposed to optimize the diesel generator and BESS capacity, considering the energy supply to the consumer by the HEES and the main distribution grid. Case studies involving commercial and residential customers in Brazil are introduced considering the normative resolutions from ANEEL, the Brazilian Regulatory Agency. Comparative analyses are made concerning an exhaustive search procedure and the commercial software Homer Pro, designed to optimize the operation of HEES systems. An important conclusion is that the proposed approach is as effective as the cutting-edge tools, with reasonable computational effort.
2022
Authors
Nogueira, AFR; Oliveira, HS; Machado, JJM; Tavares, JMRS;
Publication
SENSORS
Abstract
Audio recognition can be used in smart cities for security, surveillance, manufacturing, autonomous vehicles, and noise mitigation, just to name a few. However, urban sounds are everyday audio events that occur daily, presenting unstructured characteristics containing different genres of noise and sounds unrelated to the sound event under study, making it a challenging problem. Therefore, the main objective of this literature review is to summarize the most recent works on this subject to understand the current approaches and identify their limitations. Based on the reviewed articles, it can be realized that Deep Learning (DL) architectures, attention mechanisms, data augmentation techniques, and pretraining are the most crucial factors to consider while creating an efficient sound classification model. The best-found results were obtained by Mushtaq and Su, in 2020, using a DenseNet-161 with pretrained weights from ImageNet, and NA-1 and NA-2 as augmentation techniques, which were of 97.98%, 98.52%, and 99.22% for UrbanSound8K, ESC-50, and ESC-10 datasets, respectively. Nonetheless, the use of these models in real-world scenarios has not been properly addressed, so their effectiveness is still questionable in such situations.
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