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Publications

2016

Real Time Analytics for Characterizing the Computer User's State

Authors
CARNEIRO, D; ARAÚJO, D; PIMENTA, A; NOVAIS, P;

Publication
ADCAIJ: ADVANCES IN DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE JOURNAL

Abstract

2016

ProcessPAIR: A Tool for Automated Performance Analysis and Improvement Recommendation in Software Development

Authors
Raza, M; Faria, JP;

Publication
2016 31ST IEEE/ACM INTERNATIONAL CONFERENCE ON AUTOMATED SOFTWARE ENGINEERING (ASE)

Abstract
High-maturity software development processes can generate significant amounts of data that can be periodically analyzed to identify performance problems, determine their root causes and devise improvement actions. However, conducting that analysis manually is challenging because of the potentially large amount of data to analyze and the effort and expertise required. In this paper, we present ProcessPAIR, a novel tool designed to help developers analyze their performance data with less effort, by automatically identifying and ranking performance problems and potential root causes, so that subsequent manual analysis for the identification of deeper causes and improvement actions can be properly focused. The analysis is based on performance models defined manually by process experts and calibrated automatically from the performance data of many developers. We also show how ProcessPAIR was successfully applied for the Personal Software Process (PSP). A video about ProcessPAIR is available in https://youtu.be/dEk3fhhkduo.

2016

Automatic Cattle Identification Using Graph Matching Based on Local Invariant Features

Authors
Monteiro, FC;

Publication
IMAGE ANALYSIS AND RECOGNITION (ICIAR 2016)

Abstract
Cattle muzzle classification can be considered as a biometric identifier important to animal traceability systems to ensure the integrity of the food chain. This paper presents a muzzle-based classification system that combines local invariant features with graph matching. The proposed approach consists of three phases; namely feature extraction, graph matching, and matching refinement. The experimental results showed that our approach is superior than existing works as ours achieves an all correct identification for the tested images. In addition, the results proved that our proposed method achieved this high accuracy even if the testing images are rotated in various angles.

2016

Communication-free control solution for the provision of frequency regulation services in HVDC grids: Numerical simulation and experimental validation in a reduced scale platform

Authors
Moreira, CL; Gouveia, JR; Rodrigues, J; Silva, B; Peças Lopes, JA;

Publication
CIGRE Session 46

Abstract
The development of future HVDC grids for transnational interconnections and offshore wind farms development should be compliant with specific requirements regarding frequency support and inertia emulation. Therefore, this paper presents the development of communication-free control solutions capable of dealing with these control requirements. The proposed solution exploit a coordinated control approach between offshore wind turbines and VSC-HVDC converter stations based on the DC grid voltage modulation. The effectiveness of the proposed control solutions are demonstrated to be of utmost importance for improving future grids frequency regulation capabilities. Recognizing that numerical simulations provide valuable knowledge regarding HVDC grids operation and control, this paper introduces a further step encompassing the development of a reduced scale laboratorial prototype of a DC grid making possible the demonstration of key frequency control functionalities. Following the theoretical/conceptual background that is demonstrated through numerical simulation, laboratorial tests were then performed in order to test and demonstrate the performance and effectiveness of the proposed control mechanisms that future HVDC grids will provide to frequency control in mainland AC grids.

2016

Aptamer-based fiber sensor for thrombin detection

Authors
Coelho, L; Marques Martins de Almeida, JMM; Santos, JL; da Silva Jorge, PAD; Martins, MCL; Viegas, D; Queiros, RB;

Publication
JOURNAL OF BIOMEDICAL OPTICS

Abstract
The detection of thrombin based on aptamer binding is studied using two different optical fiber-based configurations: long period gratings coated with a thin layer of titanium dioxide and surface plasmon resonance devices in optical fibers coated with a multilayer of gold and titanium dioxide. These structures are functionalized and the performance to detect thrombin in the range 10 to 100 nM is compared in transmission mode. The sensitivity to the surrounding refractive index (RI) of the plasmonic device is higher than 3100 nmRIU(-1) in the RI range 1.335 to 1.355, a factor of 20 greater than the sensitivity of the coated grating. The detection of 10 nM of thrombin was accomplished with a wavelength shift of 3.5 nm and a resolution of 0.54 nM. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

2016

Salience in a social landscape: electrophysiological effects of task-irrelevant and infrequent vocal change

Authors
Pinheiro, AP; Barros, C; Pedrosa, J;

Publication
SOCIAL COGNITIVE AND AFFECTIVE NEUROSCIENCE

Abstract
In a dynamically changing social environment, humans have to face the challenge of prioritizing stimuli that compete for attention. In the context of social communication, the voice is the most important sound category. However, the existing studies do not directly address whether and how the salience of an unexpected vocal change in an auditory sequence influences the orientation of attention. In this study, frequent tones were interspersed with task-relevant infrequent tones and task-irrelevant infrequent vocal sounds (neutral, happy and angry vocalizations). Eighteen healthy college students were asked to count infrequent tones. A combined event-related potential (ERP) and EEG time-frequency approach was used, with the focus on the P3 component and on the early auditory evoked gamma band response, respectively. A spatial-temporal principal component analysis was used to disentangle potentially overlapping ERP components. Although no condition differences were observed in the 210-310 ms window, larger positive responses were observed for emotional than neutral vocalizations in the 310-410 ms window. Furthermore, the phase synchronization of the early auditory evoked gamma oscillation was enhanced for happy vocalizations. These findings support the idea that the brain prioritizes the processing of emotional stimuli, by devoting more attentional resources to salient social signals even when they are not task-relevant.

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