Cookies
O website necessita de alguns cookies e outros recursos semelhantes para funcionar. Caso o permita, o INESC TEC irá utilizar cookies para recolher dados sobre as suas visitas, contribuindo, assim, para estatísticas agregadas que permitem melhorar o nosso serviço. Ver mais
Aceitar Rejeitar
  • Menu
Publicações

2021

Optical Vernier Effect: Recent Advances and Developments

Autores
Gomes, AD; Bartelt, H; Frazao, O;

Publicação
LASER & PHOTONICS REVIEWS

Abstract
The optical analog of the Vernier effect applied to fiber interferometers is a recent tool to enhance the sensitivity and resolution of optical fiber sensors. This effect relies on the overlap between the signals of two interferometers with slightly detuned interference frequencies. The Vernier envelope modulation generated at the output spectrum presents magnified sensing capabilities (i.e., magnified wavelength shift) compared to that of the individual sensing interferometers that constitute the system, leading to a new generation of highly sensitive fiber sensing devices. This review analyses the recent advances and developments of the optical Vernier effect from a fiber sensing point-of-view. Initially, the fundamentals of the effect are introduced, followed by an extensive review on the state-of-the-art, presenting all the different configurations and types of fiber sensing interferometers used to introduce the optical Vernier effect. This paper also includes an overview of the complex case of enhanced Vernier effect and the introduction of harmonics to the effect.

2021

CAD systems for colorectal cancer from WSI are still not ready for clinical acceptance

Autores
Oliveira, SP; Neto, PC; Fraga, J; Montezuma, D; Monteiro, A; Monteiro, J; Ribeiro, L; Goncalves, S; Pinto, IM; Cardoso, JS;

Publicação
SCIENTIFIC REPORTS

Abstract
Most oncological cases can be detected by imaging techniques, but diagnosis is based on pathological assessment of tissue samples. In recent years, the pathology field has evolved to a digital era where tissue samples are digitised and evaluated on screen. As a result, digital pathology opened up many research opportunities, allowing the development of more advanced image processing techniques, as well as artificial intelligence (AI) methodologies. Nevertheless, despite colorectal cancer (CRC) being the second deadliest cancer type worldwide, with increasing incidence rates, the application of AI for CRC diagnosis, particularly on whole-slide images (WSI), is still a young field. In this review, we analyse some relevant works published on this particular task and highlight the limitations that hinder the application of these works in clinical practice. We also empirically investigate the feasibility of using weakly annotated datasets to support the development of computer-aided diagnosis systems for CRC from WSI. Our study underscores the need for large datasets in this field and the use of an appropriate learning methodology to gain the most benefit from partially annotated datasets. The CRC WSI dataset used in this study, containing 1,133 colorectal biopsy and polypectomy samples, is available upon reasonable request.

2021

Terrace Vineyards Detection from UAV Imagery Using Machine Learning: A Preliminary Approach

Autores
Figueiredo, N; Pádua, L; Sousa, JJ; Sousa, A;

Publicação
PROGRESS IN ARTIFICIAL INTELLIGENCE (EPIA 2021)

Abstract
Alto Douro Wine Region is located in the Northeast of Portugal and is classified by UNESCO as a World Heritage Site. Snaked by the Douro River, the region has been producing wines for over 2000 years, with the world-famous Porto wine standing out. The vineyards, in that region, are built in a territory marked by steep slopes and the almost inexistence of flat land and water. The vineyards that cover the great slopes rise from the Douro River and form an immense terraced staircase. All these ingredients combined make the right key for exploring precision agriculture techniques. In this study, a preliminary approach allowing to perform terrace vineyards identification is presented. This is a key-enabling task towards the achievement of important goals such as production estimation and multi-temporal crop evaluation. The proposed methodology consists in the use of Convolutional Neural Networks (CNNs) to classify and segment the terrace vineyards, considering a high-resolution dataset acquired with remote sensing sensors mounted in unmanned aerial vehicles (UAVs).

2021

Preface to special issue: LSFA 2017 and 2018

Autores
Alves, S; Wassermann, R;

Publicação
Math. Struct. Comput. Sci.

Abstract

2021

Increasing the PV Hosting Capacity in Unbalanced Three-Phase Distribution Networks Through Reconfiguration with Closed-Loop Operation

Autores
Macedo, LH; Vargas, R; Home Ortiz, JM; Mantovani, JRS; Romero, R; Catalao, JPS;

Publicação
2021 21ST IEEE INTERNATIONAL CONFERENCE ON ENVIRONMENT AND ELECTRICAL ENGINEERING AND 2021 5TH IEEE INDUSTRIAL AND COMMERCIAL POWER SYSTEMS EUROPE (EEEIC/I&CPS EUROPE)

Abstract
This article presents a novel mixed-integer nonlinear linear programming (MINLP) model to increase the photovoltaic (PV) hosting capacity in unbalanced three- phase electrical distribution systems. The problem considers the optimal operation of capacitor banks and network reconfiguration with radial and closed-loop operation. The objective function maximizes the PV hosting capacity of the system. A set of linearization strategies are employed to convert the presented MINLP model into a mixed-integer linear programming (MILP) problem. By considering the MILP formulation, optimality is guaranteed by using off-the-shelf optimization solvers. Several tests are carried out using a 25-node unbalanced three-phase distribution system. When examining network reconfiguration with radial and closed-loop operation, the results demonstrate that the proposed formulation is effective in increasing the penetration of PV sources.

2021

EN 301 549: Parameter decoding, evolution and translation into European Portuguese - Steps towards the creation of a tool for the application of ICT accessibility requirements in public procurement

Autores
Martins, M; Godinho, F; Gonçalves, P; Gonçalves, R;

Publicação
2021 8TH INTERNATIONAL CONFERENCE ON ICT & ACCESSIBILITY (ICTA)

Abstract
Legislation on Information and Communication Technologies (ICT) accessibility is not new and therefore there are many national and international initiatives in place, although very web-focused. We are now on the threshold of a more comprehensive approach in the field of ICT. The European Standard EN 301 549 specifies the accessibility requirements for public procurement of ICT products and services in Europe. This study focuses both on the parameter decoding and the evolution of the European standard EN 301 549, and the translation process into European Portuguese. These were some of the steps considered for the creation of ICT Accessibility Requirements Tool (FRATIC, Ferramenta de Requisitos de Acessibilidade para TIC), designed and developed within the framework of the research under which this study falls, in order to simplify the enforcement of EN 301 549 in public procurement procedures in Portugal.

  • 1236
  • 4544