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Publications

2018

Characterization of deterioration of fallow deer and goat meat using microbial and mid infrared spectroscopy in tandem with chemometrics

Authors
Moreira, MJP; Silva, AC; de Almeida, JMMM; Saraiva, C;

Publication
FOOD PACKAGING AND SHELF LIFE

Abstract
It is established that FTIR with chemometrics is a reliable technique to predict deterioration of meat from game species and from species grown in the wild such as, fallow deer and goat. Meat was minced and stored for periods of 12-432 h and examined for FTIR, pH, lipid oxidation, microbiological analysis, colour, and sensory analysis (SA). Spectral data was analysed with PCA and LDA. PLS-R was employed to establish relationships between spectral data and the microbiological counts. From PCA it was determined that wavenumber from 1656 to 1002 cm(-1) are linked to alterations during storage. LDA of spectral data was applied to sustain SA data. For fallow deer the room mean square error of prediction values for external samples were 0.75, 0.61, 0.81 and 0.73 log cfu g(-1), for TVC, psychrotrophs, LAB, and Enterobacteriaceae, respectively. For goat, the corresponding values were 0.74, 0.68, 0.78 and 0.79 log cfu g(-1). FTIR spectroscopy can be used as a reliable method for assessment of freshness of meat from fallow deer and goat during storage.

2018

Analysis of amplification in a fiber ring resonator with a fabry-perot cavity

Authors
Magalhaes, R; Silva, S; Frazao, O;

Publication
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS

Abstract
The placement of an Erbium-doped Fiber Amplifier and a Fabry-Perot cavity inside a fiber ring resonator can generate a sinusoidal modulation in the optical signal obtained. The characterization of this behavior is achieved by changing the length of the Fabry-Perot cavity, which acts as a sensing device. A theoretical model of the optical signal modulation obtained with such configuration is also presented.

2018

Crowdsourcing and Massively Collaborative Science: A Systematic Literature Review and Mapping Study

Authors
Correia, A; Schneider, D; Fonseca, B; Paredes, H;

Publication
CRIWG

Abstract
Current times are denoting unprecedented indicators of scientific data production, and the involvement of the wider public (the crowd) on research has attracted increasing attention. Drawing on review of extant literature, this paper outlines some ways in which crowdsourcing and mass collaboration can leverage the design of intelligent systems to keep pace with the rapid transformation of scientific work. A systematic literature review was performed following the guidelines of evidence-based software engineering and a total of 148 papers were identified as primary after querying digital libraries. From our review, a lack of methodological frameworks and algorithms for enhancing interactive intelligent systems by combining machine and crowd intelligence is clearly manifested and we will need more technical support in the future. We lay out a vision for a cyberinfrastructure that comprises crowd behavior, task features, platform facilities, and integration of human inputs into AI systems.

2018

Loading constraints for a multi-compartment vehicle routing problem

Authors
Ostermeier, M; Martins, S; Amorim, P; Huebner, A;

Publication
OR SPECTRUM

Abstract
Multi-compartment vehicles (MCVs) can deliver several product segments jointly. Separate compartments are necessary as each product segment has its own specific characteristics and segments cannot be mixed during transportation. The size and position of the compartments can be adjusted for each tour with the use of flexible compartments. However, this requires that the compartments can be accessed for loading/unloading. The layout of the compartments is defined by the customer and segment sequence, and it needs to be organized in a way that no blocking occurs during loading/unloading processes. Routing and loading layouts are interdependent for MCVs. This paper addresses such loading/unloading issues raised in the distribution planning when using MCVs with flexible compartments, loading from the rear, and standardized transportation units. The problem can therefore be described as a two-dimensional loading and multi-compartment vehicle routing problem (2L-MCVRP). We address the problem of obtaining feasible MCV loading with minimal routing, loading and unloading costs. We define the loading problem that configures the compartment setup. Consequently, we develop a branch-and-cut (B&C) algorithm as an exact approach and extend a large neighborhood search (LNS) as a heuristic approach. In both cases, we use the loading model in order to verify the feasibility of the tours and to assess the problem as a routing and loading problem. The loading model dictates the cuts to be performed in the B&C, and it is used as a repair mechanism in the LNS. Numerical studies show that the heuristic reaches the optimal solution for small instances and can be applied efficiently to larger problems. Additionally, further tests on large instances enable us to derive general rules regarding the influence of loading constraints. Our results were validated in a case study with a European retailer. We identified that loading constraints matter even for small instances. Feasible loading can often be achieved only through minor changes to the routing solution and therefore with limited additional costs. Further, the importance to integrate loading constraints grows as the problem size increases, especially when a heterogeneous mix of segments is ordered.

2018

Driver drowsiness detection: a comparison between intrusive and non-intrusive signal acquisition methods

Authors
Oliveira, L; Cardoso, JS; Lourenco, A; Ahlstrom, C;

Publication
PROCEEDINGS OF THE 2018 7TH EUROPEAN WORKSHOP ON VISUAL INFORMATION PROCESSING (EUVIP)

Abstract
Driver drowsiness is a major cause of road accidents, many of which result in fatalities. A solution to this problem is the inclusion of a drowsiness detector in vehicles to alert the driver if sleepiness is detected. To detect drowsiness, physiologic, behavioral (visual) and vehicle-based methods can be used, however, only measures that can be acquired non-intrusively are viable in a real life application. This work uses data from a real-road experiment with sleep deprived drivers to compare the performance of driver drowsiness detection using intrusive acquisition methods, namely electrooculogram (EOG), with camera based, non-intrusive, methods. A hybrid strategy, combining the described methods with electrocardiogram (ECG) measures, is also evaluated. Overall, the obtained results show that drowsiness detection performance is similar using non-intrusive camera based measures or intrusive EOG measures. The detection performance increases when combining two methods (ECG + visual) or (ECG + EOG).

2018

End-to-End Ovarian Structures Segmentation

Authors
Wanderley, DS; Carvalho, CB; Domingues, A; Peixoto, C; Pignatelli, D; Beires, J; Silva, J; Campilho, A;

Publication
CIARP

Abstract
The segmentation and characterization of the ovarian structures are important tasks in gynecological and reproductive medicine. Ultrasound imaging is typically used for the medical diagnosis within this field but the understanding of the images can be difficult due to their characteristics. Furthermore, the complexity of ultrasound data may lead to a heavy image processing, which makes the application of classical methods of computer vision difficult. This work presents the first supervised fully convolutional neural network (fCNN) for the automatic segmentation of ovarian structures in B-mode ultrasound images. Due to the small dataset available, only 57 images were used for training. In order to overcome this limitation, several regularization techniques were used and are discussed in this paper. The experiments show the ability of the fCNN to learn features to distinguish ovarian structures, achieving a Dice similarity coefficient (DSC) of 0.855 for the segmentation of the stroma and a DSC of 0.955 for the follicles. When compared with a semi-automatic commercial application for follicle segmentation, the proposed fCNN achieved an average improvement of 19%.

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