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- Smart Helmet: An Experimental Helmet Security Add-OnPublication . Sales, David; Prata, Paula; Fazendeiro, PauloWhen it comes to ride a motorcycle the drivers-centered road safety is quintessential; every year a remarkable number of accidents directly related to sleepiness and fatigue occur. With the objective of maximizing the security on a motorcycle, the reported system aims to prevent sleepiness related accidents and to attenuate the effects of a crash. The system was developed as the less intrusive as it could be, with sensors that allow the capture of reaction times to stimuli-response and collect acceleration values. To obviate the lack of data related to sleepiness during motorcycle riding, a machine learning system was developed, based on Artificial Immune Systems. This way, resourcing to a minimum amount of user input, a custom system is synthesized for each user, allowing to assess the sleepiness level of each subject differently.
- A gyro-enhanced smart-phone framework to develop motion-based user interfaces for animation and virtual environmentsPublication . Pereira, Tiago; Pereira, Orlando; Fazendeiro, Paulo; Gomes, AbelIn this paper, the mobile phone is presented as an alternative device to interact with animation systems and virtual environments, including video games. Basically, we show how the gyroscope of a mobile device can work as a sensor to control the pose and motion of a mobile device controlled object or character in a 3D virtual world. More specifically, we introduce a framework that enables the development and rapid prototyping of motion-based user interfaces for animation systems and virtual environments. This framework provides tools to capture and control the motion of mobile devices-binded objects in a 3D virtual scene over a wireless communication channel via a simple, fast and efficient protocol named Open Sound Control (OSC).
- Anonymized Data Assessment via Analysis of Variance: An Application to Higher Education EvaluationPublication . Ferrão, Maria Eugénia; Prata, Paula; Fazendeiro, PauloThe assessment of the utility of an anonymized data set can be operational-ized by the determination of the amount of information loss. To investigate the possible degradation of the relationship between variables after anony-mization, hence measuring the loss, we perform an a posteriori analysis of variance. Several anonymized scenarios are compared with the original data. Differential privacy is applied as data anonymization process. We assess data utility based on the agreement between the original data structure and the anonymized structures. Data quality and utility are quantified by standard metrics, characteristics of the groups obtained. In addition, we use analysis of variance to show how estimates change. For illustration, we apply this ap-proach to Brazilian Higher Education data with focus on the main effects of interaction terms involving gender differentiation. The findings indicate that blindly using anonymized data for scientific purposes could potentially un-dermine the validity of the conclusions.
- Societal risks of the end of physical cashPublication . Almeida, Pedro De; Fazendeiro, Paulo; Inácio, Pedro R. M.Cash, standardized physical tokens that represent economic value, has been a key instrument in the evolution of human civilizations for around 3000 years. However in the last few decades cash has been progressively losing its preeminence in favour of electronic handling of money transactions. The shift to a cashless society, in which physical money is completely or almost completely replaced by electronic records is on the horizon. Regardless of its advantages and disadvantages, electronic handling of money needs the support of a complex technological infrastructure which operation depends on many factors. This paper discusses this subject in detail, identifies the main threats linked to electronic money handling and evaluates their possible impacts on societies that no longer rely on cash.
- Utility-driven assessment of anonymized data via clusteringPublication . Ferrão, Maria Eugénia; Prata, Paula; Fazendeiro, PauloIn this study, clustering is conceived as an auxiliary tool to identify groups of special interest. This approach was applied to a real dataset concerning an entire Portuguese cohort of higher education Law students. Several anonymized clustering scenarios were compared against the original cluster solution. The clustering techniques were explored as data utility models in the context of data anonymization, using k-anonymity and (ε, δ)-differential as privacy models. The purpose was to assess anonymized data utility by standard metrics, by the characteristics of the groups obtained, and the relative risk (a relevant metric in social sciences research). For a matter of self-containment, we present an overview of anonymization and clustering methods. We used a partitional clustering algorithm and analyzed several clustering validity indices to understand to what extent the data structure is preserved, or not, after data anonymization. The results suggest that for low dimensionality/cardinality datasets the anonymization procedure easily jeopardizes the clustering endeavor. In addition, there is evidence that relevant field-of-study estimates obtained from anonymized data are biased.
- Synchronization Overlap Trade-Off for a Model of Spatial Distribution of SpeciesPublication . Bioco, João; Prata, Paula; Cánovas, Fernando; Fazendeiro, PauloDespite of the widespread implementation of agent-based models in ecological modeling and another several areas, modelers have been concerned by the time consuming of these type of models. This paper presents a strategy to parallelize an agent-based model of spatial distribution of biological species, operating in a multi-stage synchronous distributed memory mode, as a way to obtain gains in the performance while reducing the need for synchronization. A multiprocessing implementation divides the environment (a rectangular grid corresponding to the study area) into stage-subsets, according to the number of defined or available processes. In order to ensure that there is no information loss, each stage-subset is extended with an overlapping section from each one of its neighbouring stage-subsets. The effect of the size of this overlapping on the quality of the simulations is studied. These results seem to indicate that it is possible to establish an optimal trade-off between the level of redundancy and the synchronization frequency. The reported paralellization method was tested in a standalone multicore machine but may be seamlessly scalable to a computation cluster.
- Applications of artificial immune systems to computer security: A surveyPublication . Fernandes, Diogo A. B.; Freire, Mario; Fazendeiro, Paulo; Inácio, Pedro R. M.For the last two decades, artificial immune systems have been studied in various fields of knowledge. They were shown to be particularly effective tools at detecting anomalous behavior in the security domain of computer systems. This article introduces the principles of artificial immune systems and surveys several works applying such systems to computer security problems. The works herein discussed are summarized and open issues are pointed out afterwards, elaborating on a novel applicability of these systems to cloud computing environments.
- SDSim: A generalized user friendly web ABM system to simulate spatiotemporal distribution of species under environmental scenariosPublication . Bioco, João; Cánovas, Fernando; Prata, Paula; Fazendeiro, PauloThis paper presents the Agent-Based Modelling System of spatial distribution of species SDSim. SDSim is an agent-based modelling system designed to simulate spatial distribution of species and populations for conservation and management purposes. SDSim gives to modellers the ability to simulate movements and colonization patterns of species given locations under study and a set of eco-geographical variables in which species depends on.
- Remarks on the Behavior of an Agent-Based Model of Spatial Distribution of SpeciesPublication . Bioco, João; Prata, Paula; Cánovas, Fernando; Fazendeiro, PauloAgent-based models have gained considerable notoriety in ecological modeling as well as in several other fields yearning for the ability to capture the emergent behavior of a complex system in which individuals interact with each other and with their environment. These models are implemented by applying a bottom-up approach, where the entire behavior of the system emerges from the local interaction between their components (agents or individuals). Usually, these interactions between individuals and their enclosing environment are modeled by very simple local rules. From the conceptual point of view, another appealing characteristic of this simulation approach is that it is well aligned with the reality whenever the system is composed of a multitude of individuals (behavioral units) that can be flexibly combined and placed in the environment. Due to their inherent flexibility, and despite of their simplicity, it is necessary to pay attention to the adjustments in their parameters which may result in unforeseen changes on the overall behavior of these models. In this paper we study the behavior of an agent-based model of spatial distribution of species, by analyzing the effects of the model parameters and the implications of the environment variables (that compose the environment where the species lives) on the models’ output. The presented experiments show that the behavior of the model depends mainly on the conditions of the environment where the species live, and the main parameters presented in life cycle of the species.
- Prediction of the Arbutus unedo colonization time via an agent-based distribution modelPublication . Bioco, João; Prata, Paula; Canovas, Fernando; Fazendeiro, PauloSpecies distribution models (SDMs) have been used to predict the distribution of species in an environment. Usually, this prediction is based on previous species occurrence data. Nowadays, several species are facing climatic changes that impact the way species behave. Global warming has implicated species displacement from their natural habitat to new suitable places. SDMs can be used to anticipate possible impacts of the climatic changes in species distribution, preventing species extinction scenarios. New SDMs approaches are needed to give valuable information that better approximates these models to reality. This paper presents a novel approach to the prediction of species distribution. It starts by using an agent-based model (ABM) to establish an approximate mapping between the geological and the computational times. Afterwards, the implemented ABM can be used to predict the species distribution at different time intervals. The presented case study concerns the distribution of the Arbutus unedo in the Iberian peninsula, a species with relevant socio-economic impact in Portugal. The results show that the measurement of the geological time, supported by the approximate correspondence to the number of epochs of an ABM, can be a valuable tool for the prediction of the species distribution in a changing environmental scenario.