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Automatic allocation of safety requirements to components of a software product line
No full textSafety critical systems developed as part of a product line must still comply with safety standards. Standards use the concept of Safety Integrity Levels (SILs) to drive the assignment of system safety requirements to components of a system under design. However, for a Software Product Line (SPL), the safety requirements that need to be allocated to a component may vary in different products. Variation in design can indeed change the possible hazards incurred in each product, their causes, and can alter the safety requirements placed on individual components in different SPL products. Establishing common SILs for components of a large scale SPL by considering all possible usage scenarios, is desirable for economies of scale, but it also poses challenges to the safety engineering process. In this paper, we propose a method for automatic allocation of SILs to components of a product line. The approach is applied to a Hybrid Braking System SPL design.CNPq (152693/2011-4)CAPE
CanIHelp: a platform for inclusive collaboration
No full textTechnology plays a key role in daily life of people with special needs, being a mean of integration or even communication with society. By built up experience, we find that support tools play a crucial part in empowerment of persons with special needs and small advances may represent shifts and opportunities. The diversity of solutions and the need for dedicated hardware to each feature represents a barrier to its use, compromising the success of the solutions against, among others, problems of usability and scale. This paper aims to explore the concept of inclusive collaboration to enhance the mutual interaction and assistance. The proposed approach combines and generalizes the usage of human computation in a collaborative environment with assistive technologies creating redundancy and complementarity in the solutions provided, contributing to enhance the quality of life of people with special needs and the elderly. The CanIHelp platform is an embodiment of the concept as a result from an orchestrated model using mechanisms of collective intelligence through social inclusion initiatives. The platform features up for integrating assistive technologies, collaborative tools and multiple multimedia communication channels, accessible through multimodal interfaces for universal access. A discussion of the impacts of fostering collaboration and broadening from the research concepts to the societal impacts is presented. As final remarks a set of future research challenges and guidelines are identified.FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project UID/EEA/50014 /2013 and research grants SFRH/BD/89759/2012 and SFRH/BD/87259/2012International Conference on Human-Computer Interaction - HCI (2015 Los Angeles); International Conference on Universal Access in Human-Computer Interaction - UAHCI (9. 2015 Los Angeles
Adaptive positive selection for keystroke dynamics
No full textCurrent technologies provide state of the art services but, at the same time, increase data exposure, mainly due to Internet-based applications. In view of this scenario, improved authentication mechanisms are needed. Keystroke dynamics, which recognizes users by their typing rhythm, is a cost-effective alternative. This technology usually only requires a common keyboard in order to acquire authentication data. There are several studies investigating the use of machine learning techniques for user authentication based on keystroke dynamics. However, the majority of them assume a scenario which the user model is not updated. It is known that typing rhythm changes over time (concept drift). Consequently, classification algorithms in keystroke dynamics have to be able to adapt the user model to these changes. This paper evaluates adaptation methods for an immune positive selection algorithm in a data stream context. Experimental results showed that they improved classification performance, mainly for false rejection rates.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
A multi-objective optimization approach associated to climate change analysis to improve Systematic Conservation Planning
No full textBiodiversity conservation has been since long an academic community concern, leading scientists to propose strategies to effectively meet conservation goals. In particular, Systematic Conservation Planning (SCP) aims to determine the most cost effective way of investing in conservation actions. SCP can be formalized by the Set-Covering Problem, which is NP-hard. SCP is inherently multi-objective, although it has been usually treated with a monobjective and static approach. Here, we propose a multi-objective solution for SCP, increasing its flexibility and complexity, and, at the same time, augmenting the quality of provided information, which reinforces decision-making. We used ensemble forecasting, considering future climate simulations to estimate species occurrence projected to 2080. Our method identifies sites: 1) of high priority for conservation; 2) with significant risk of investment; and, 3) that may become attractive in the future. To the best of our knowledge, this application to a real-world problem in ecology is the first attempt to apply multi-objective optimization to SCP associated to climate forecasting, in a dynamic spatial prioritization analysis for biodiversity conservation.CNPq throughout a Science without Borders scholarshipThe Royal SocietyCNPq/MCT/CAPES (projects #564717/2010-0 and #563624/2010-8)GECER (PRONEX/FAPEG/CNPq CP 07-2009)International Conference on Evolutionary Multi-criterion Optimization - EMO (8. 2015 Guimarães
3D edge detection based on Boolean functions and local operators
No full textEdge detection is one of the most commonly used operations in image processing and computer vision areas. Edges correspond to the boundaries between regions in an image, which are useful for object segmentation and recognition tasks. This work presents a novel method for 3D edge detection based on Boolean functions and local operators, which is an extension of the 2D edge detector introduced by Vemis et al. [Signal Processing 45(2), 161–172 (1995)] The proposed method is composed of two main steps. An adaptive binarization process is initially applied to blocks of the image and the resulting binary map is processed with a set of Boolean functions to identify edge points within the blocks. A global threshold, calculated to estimate image intensity variation, is then used to reduce false edges in the image blocks. The proposed method is compared to other 3D gradient filters: Canny, Monga–Deriche, Zucker–Hummel and Sobel operators. Experimental results demonstrate the effectiveness of the proposed technique when applied to several 3D synthetic and real data sets.FAPESPCNPqCAPE
An efficient solution to perform automatic meter reading using an unmanned aerial vehicle
No full textThe most electrical power suppliers to recruit meter readers to carry out collection of power consumption of the\ud
consumers. This activity is done manually and can provide error and cause financial and physical losses. Solutions have\ud
been proposed in the literature focusing on more efficient routes for meter readers or the use of a car to perform the task\ud
remotely, which can increase the cost and have delayed task by problems of transit traffic. To overcome these challenges\ud
and constraints, we propose an architecture to automatic meter reading (AMR) system using Unmanned Aerial Vehicles.\ud
Two main contributions can be absorbed of this solution: i) the meter readers are no longer needed; ii) reducing the time\ud
and distance to carry out the collection of the readings from the power meters. In addition a protocol that ensures wireless\ud
communication between the Unmanned Aerial Vehicle and the power meters was designed. The solution was validated\ud
and evaluated in an urban environment and the results achieved show a decrease up to 72.6% of time and 45.1% of the\ud
distance as compared to the use a car. The communication protocol can avoid at least 98.3% of packet collisions.CNPq (processos 473493/2013-6, 147356/2013-0 e 486332/2013-6)FAPESPFundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG
Gradient-based optimization techniques for the design of static controllers for Markov jump linear systems with unobservable modes
No full textThe paper formulates the static control problem of Markov jump linear systems, assuming that the controller does not have access to the jump variable. We derive the expression of the gradient for the cost motivated by the evaluation of 10 gradient-based optimization techniques. The numerical efficiency of these techniques is verified by using the data obtained from practical experiments. The corresponding solution is used to design a scheme to control the velocity of a real-time DC motor device subject to abrupt power failuresFAPESP (03 / 06736-7, 04 / 06947-0)CNPq (471557 / 2009-9, 304.856 / 2007-0, 304.429 / 2007-4, 306.466 / 2010-4)Fundación Carolina (Fundación Carolina - Programa "Movilidad de Professores e Investigadores Brasil-España. C.2010 "
General subpopulation framework and taming the conflict inside populations
No full textStructured evolutionary algorithms have been investigated for some time. However,\ud
they have been under explored especially in the field of multi-objective optimization.\ud
Despite good results, the use of complex dynamics and structures keep the understanding\ud
and adoption rate of structured evolutionary algorithms low. Here, we propose a\ud
general subpopulation framework that has the capability of integrating optimization\ud
algorithms without restrictions as well as aiding the design of structured algorithms.\ud
The proposed framework is capable of generalizing most of the structured evolutionary\ud
algorithms, such as cellular algorithms, island models, spatial predator-prey, and\ud
restricted mating based algorithms. Moreover, we propose two algorithms based on\ud
the general subpopulation framework, demonstrating that with the simple addition\ud
of a number of single-objective differential evolution algorithms for each objective,\ud
the results improve greatly, even when the combined algorithms behave poorly when\ud
evaluated alone at the tests. Most importantly, the comparison between the subpopulation\ud
algorithms and their related panmictic algorithms suggests that the competition\ud
between different strategies inside one population can have deleterious consequences\ud
for an algorithm and reveals a strong benefit of using the subpopulation framework
From tele-operated robots to social robots with autonomous behaviors
No full textThis paper presents a perception/interface device for Telepresence Mobile Robots using a Kinect sensor. Firstly, using the Kinect RGB camera (Webcam) and image processing techniques, it is possible to detect a human face, allowing the robot to track the face, getting closer of a person, moving forward and rotating to get a better pose (position and orientation) to interact with him/her. Then it is possible to recognize hand gestures using the Kinect 3D sensor (Depth camera). The proposed gesture recognition method tracks the hands positions and movements, when moving it forward towards the robot, and then recognizing a set of predefined gestures/commands. Finally, the 3D perception provided by the Kinect also allows us to detect obstacles, avoiding collisions and safely moving the mobile robot base, also allowing to search for someone in the environment. Practical experiments are presented demonstrating the obtained results: (i) in the searching and tracking of human faces; (ii) in the robot positioning related to the user we want to interact with; and also (iii) in the human gesture recognition.CAPES/D