Papers by Paulo Fazendeiro
Anonymized Data Assessment via Analysis of Variance: An Application to Higher Education Evaluation
Lecture Notes in Computer Science, 2023
A gyro-enhanced smart-phone framework to develop motion-based user interfaces for animation and virtual environments
In this paper, the mobile phone is presented as an alternative device to interact with animation ... more In 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).
A Cellular Automata Model of Spatio-Temporal Distribution of Species
Advances in intelligent systems and computing, 2019
Cellular automata (CA) are discrete models used in several studies due to the capacity to simulat... more Cellular automata (CA) are discrete models used in several studies due to the capacity to simulate dynamic systems and analyze their behavior. One of the applications of CA in ecology is in the analysis of the spatial distribution of species, where simulation models are created in order to study the response of ecological systems to different kinds of exogenous or endogenous perturbations. In this study we describe an implementation of a cellular automata model able to incorporate environmental data from different sources. To the user is given the power to produce and analyze different scenarios by combining the available variables at will. We present a case study where, departing from a generalized additive model, a possible explanation is given for the distribution of two haplotypes of honeybees along Iberian Peninsula. The results of our model are compared and discussed at the light of the real data collected on the terrain.
arXiv (Cornell University), Apr 15, 2020
Artificial Intelligence algorithms have been steadily increasing in popularity and usage. Deep Le... more Artificial Intelligence algorithms have been steadily increasing in popularity and usage. Deep Learning, allows neural networks to be trained using huge datasets and also removes the need for human extracted features, as it automates the feature learning process. In the hearth of training deep neural networks, such as Convolutional Neural Networks, we find backpropagation, that by computing the gradient of the loss function with respect to the weights of the network for a given input, it allows the weights of the network to be adjusted to better perform in the given task. In this paper, we propose a hybrid method that uses both backpropagation and evolutionary strategies to train Convolutional Neural Networks, where the evolutionary strategies are used to help to avoid local minimas and fine-tune the weights, so that the network achieves higher accuracy results. We show that the proposed hybrid method is capable of improving upon regular training in the task of image classification in CIFAR-10, where a VGG16 model was used and the final test results increased 0.61%, in average, when compared to using only backpropagation.
Journal of information security and applications, Aug 1, 2017
For the last two decades, artificial immune systems have been studied in various fields of knowle... more 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.
SoTRAACE — Socio-technical risk-adaptable access control model
Within the necessary security requirements, access control measures are essential to provide adeq... more Within the necessary security requirements, access control measures are essential to provide adequate means to protect data from unauthorized accesses. However, current and traditional solutions are commonly based on predefined access policies and roles and are therefore inflexible by assuming uniform access control decisions through people's different type of devices, environments and situational conditions, and across enterprises, location and time. We live in an age of the mobile paradigm of anytime/anywhere access as the smartphone is the most ubiquitous device that people now hold. In this new age, access control models need to determine adaptable access decisions based on multiple factors aggregated at the moment of request and not just perform a predefined comparison of attributes. This paper presents a new access control model: SoTRAACE — Socio-Technical Risk-Adaptable Access Control Model. This model aggregates attributes from various domains to help performing a risk assessment that is balanced against the operational needs at the moment of each request, so to provide the most accurate and secure access decision. As a proof of concept, SoTRAACE is used to model and compare two different use case scenarios in the healthcare sector.
Prediction of the Arbutus Unedo Colonization Time via an Agent-Based Distribution Model
Lecture Notes in Computer Science, 2023
On the Modelling of Species Distribution: Logistic Regression Versus Density Probability Function
Lecture notes in networks and systems, 2022
Scientific Data
In this study, clustering is conceived as an auxiliary tool to identify groups of special interes... more In 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/c...
A Cellular Automata Model of Spatio-Temporal Distribution of Species
Advances in Intelligent Systems and Computing, 2019
Cellular automata (CA) are discrete models used in several studies due to the capacity to simulat... more Cellular automata (CA) are discrete models used in several studies due to the capacity to simulate dynamic systems and analyze their behavior. One of the applications of CA in ecology is in the analysis of the spatial distribution of species, where simulation models are created in order to study the response of ecological systems to different kinds of exogenous or endogenous perturbations. In this study we describe an implementation of a cellular automata model able to incorporate environmental data from different sources. To the user is given the power to produce and analyze different scenarios by combining the available variables at will. We present a case study where, departing from a generalized additive model, a possible explanation is given for the distribution of two haplotypes of honeybees along Iberian Peninsula. The results of our model are compared and discussed at the light of the real data collected on the terrain.
A gyro-enhanced smart-phone framework to develop motion-based user interfaces for animation and virtual environments
2016 23° Encontro Português de Computação Gráfica e Interação (EPCGI), 2016
In this paper, the mobile phone is presented as an alternative device to interact with animation ... more In 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).
SoTRAACE — Socio-technical risk-adaptable access control model
2017 International Carnahan Conference on Security Technology (ICCST), 2017
Within the necessary security requirements, access control measures are essential to provide adeq... more Within the necessary security requirements, access control measures are essential to provide adequate means to protect data from unauthorized accesses. However, current and traditional solutions are commonly based on predefined access policies and roles and are therefore inflexible by assuming uniform access control decisions through people's different type of devices, environments and situational conditions, and across enterprises, location and time. We live in an age of the mobile paradigm of anytime/anywhere access as the smartphone is the most ubiquitous device that people now hold. In this new age, access control models need to determine adaptable access decisions based on multiple factors aggregated at the moment of request and not just perform a predefined comparison of attributes. This paper presents a new access control model: SoTRAACE — Socio-Technical Risk-Adaptable Access Control Model. This model aggregates attributes from various domains to help performing a risk a...
Chapter 11 Performance Assessment Of The Canonical Genetic Algorithm: A Study On Parallel Processing Via Gpu Architectur
Smart Helmet: An Experimental Helmet Security Add-On
Lecture Notes in Networks and Systems, 2021
When it comes to ride a motorcycle the drivers-centered road safety is quintessential; every year... more When 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.
Journal of Healthcare Engineering, 2020
Background. Smartphones can tackle healthcare stakeholders’ diverse needs. Nonetheless, the risk ... more Background. Smartphones can tackle healthcare stakeholders’ diverse needs. Nonetheless, the risk of data disclosure/breach can be higher when using such devices, due to the lack of adequate security and the fact that a medical record has a significant higher financial value when compared with other records. Means to assess those risks are required for every mHealth application interaction, dependent and independent of its goals/content. Objective. To present a risk assessment feature integration into the SoTRAACE (Socio-Technical Risk-Adaptable Access Control) model, as well as the operationalization of the related mobile health decision policies. Methods. Since there is still a lack of a definition for health data security categorization, a Delphi study with security experts was performed for this purpose, to reflect the knowledge of security experts and to be closer to real-life situations and their associated risks. Results. The Delphi study allowed a consensus to be reached on e...
Joint EUSFLAT-LFA, 2005
The main objective of this work is to assess the impact of the initial conditions regarding inter... more The main objective of this work is to assess the impact of the initial conditions regarding interpretability and accuracy on the optimizer's performance and present some guidelines in order to assist the designer. Automatic infusion of anesthesia is a task where both interpretability and accuracy of the controller are highly desirable features. Under this pretext, a description on how these goals can be measured is made and a set of evolutionary optimization schemes is set up. The results show that independently of the ...
Environmental Modelling & Software, 2021
This paper presents the Agent-Based Modelling System of spatial distribution of species SDSim. SD... more This paper presents the Agent-Based Modelling System of spatial distribution of species SDSim. SDSim is an agentbased 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.
Towards Forest Fire Prevention and Combat Through Citizen Science
Advances in Intelligent Systems and Computing
A Hybrid Method for Training Convolutional Neural Networks
Lecture Notes in Networks and Systems
Synchronization Overlap Trade-Off for a Model of Spatial Distribution of Species
Computational Science and Its Applications – ICCSA 2021
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Papers by Paulo Fazendeiro