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- Light Field Image CompressionPublication . Conti, Caroline; Soares, Luís Ducla; Nunes, Paulo; Perra, Cristian; Assunção, Pedro; Sjöström, Mårten; Li, Yun; Olsson, Roger; Jennehag, UlfLight field imaging based on a single-tier camera equipped with a micro-lens array has currently risen up as a practical and prospective approach for future visual applications and services. However, successfully deploying actual light field imaging applications and services will require identifying adequate coding solutions to efficiently handle the massive amount of data involved in these systems. In this context, this chapter presents some of the most recent light field image coding solutions that have been investigated. After a brief review of the current state of the art in image coding formats for light field photography, an experimental study of the rate-distortion performance for different coding formats and architectures is presented. Then, aiming at enabling faster deployment of light field applications and services in the consumer market, a scalable light field coding solution that provides backward compatibility with legacy display devices (e.g., 2D, 3D stereo, and 3D multiview) is also presented. Furthermore, a light field coding scheme based on a sparse set of microimages and the associated blockwise disparity is also presented. This coding scheme is scalable with three layers such that the rendering can be performed with the sparse micro-image set, the reconstructed light field image, and the decoded light field image.
- An Electronic Questionnaire for Liver Assessment in Congenital Disorders of Glycosylation (LeQCDG): A Patient-Centered StudyPublication . Marques-da-Silva, Dorinda; Francisco, R.; Ferreira, V. dos Reis; Forbat, L.; Lagoa, Ricardo; Videira, P. A.; Witters, P.; Jaeken, J.; Cassiman, D.Congenital disorders of glycosylation (CDG) are ultra-rare diseases showing a great phenotypic diversity ranging from mono-to multi-organ/multisystem involvement. Liver involvement, mostly nonprogressive, is often reported in CDG patients. The main objectives of this work were (1) to better understand liver involvement in CDG patients through a liver electronic questionnaire targeting CDG families (LeQCDG) and (2) to compare responses from LeQCDG participants with literature review regarding the prevalence of liver disease and the occurrence of liver symptoms in CDG patients. The network of patient advocacy groups, families and professionals (CDG & Allies – PPAIN) developed the LeQCDG by adapting validated published questionnaires. The LeQCDG was approved by an ethics committee, and the recruitment of patients and caregivers proceeded through social media platforms. Participants were asked to report past or present liver-related symptoms (e.g. hepatomegaly, liver fibrosis and cirrhosis) and laboratory results (e.g. biochemical and/ or radiological). From 11 December 2016 to 22 January 2017, 155 questionnaires were completed. Liver disease was present in 29.9% of CDG patients. Main symptoms reported included hepatomegaly, increased levels of serum transaminases, fibrosis, steatosis and cirrhosis. The data obtained in this online survey confirm findings from a recent literature review of 25 years of published evidence (r ¼ 0.927, P ¼ 0.02). Our questionnaire collected large amounts of meaningful, clinical and patient-oriented data in a short period of time without geographic limitations. Internet-based approaches are especially relevant in the context of ultra-rare diseases such as CDG.
- Using Mental Health Indicators to Improve Health Care Management: A Web-based ApproachPublication . Vinci, André L. T.; Lima, Inacia Bezerra de; Miyoshi, Newton S. B.; Ramalho, André; Freitas, Alberto; Rijo, Rui; Alves, DomingosMental health indicators are essential for monitoring people’s mental health status, developing mental health policies, and evaluating the performance of such policies. The aim of this paper is to describe the development of a web-based tool for mental health indicators capable to support the management of Brazilian mental health care networks. The SISAM is a web information system responsible for management and provision of mental health information in Brazil and it was chosen as the use case of this study. The indicators were developed as a decision support web tool for public health managers. The tool is able to calculate 11 indicators related to inpatient care. A descriptive analysis of all indicators is presented using SISAM data from 2017. The results generated by the tool are promising and could provide improvements on care monitoring, evaluation of possible trends and investments in prevention and promotion in mental health care.
- Time-Aware Focused Web CrawlingPublication . Pereira, Pedro; Macedo, Joaquim; Craveiro, Olga; Madeira, HenriqueThere is a plethora of information inside the Web. Even the top commercial search engines can not download and index all the available information. So, in the recent years, there are several research works on the design and implementation of focused topic crawlers and also on geographic scope crawlers. Despite other areas of information retrieval, research on Web crawling is not using the temporal information extracted from Web pages in the used crawling criteria. Therefore, our research challenge is the use of temporal data extracted from Web pages as the main crawling criteria to satisfy a given temporal focus. The importance of the time dimension is quite amplified when combined with topic or geography, but now we want to study it isolated. The used approach is based on temporal segmentation of Web pages text. It only follows links within segments tagged with dates in the scope of restriction. A precision around 75% was achieved in preliminary experimental results.
- Query Expansion with Temporal Segmented TextsPublication . Craveiro, Olga; Macedo, Joaquim; Madeira, HenriqueThe use of temporal data extracted from text, to improve the effectiveness of Information Retrieval systems, has recently been the focus of important research work. Our research hypothesis is that the usage of the temporal relationship between words improves the Information Retrieval results. For this purpose, the texts are temporally segmented to establish a relationship between words and dates found in texts. This approach was applied in Query Expansion systems, using a collection with Portuguese newspaper texts. The results showed that the use of the temporality of words can enhance retrieval effectiveness. In particular for time-sensitive queries, we achieved 9.5% improvement in Precision@10. To our knowledge, this is the first work using temporal text segmentation to improve retrieval results.
- Comparative analysis of mandibular symphysis platesPublication . Dinis, Jairson C.; Kemmoku, Daniel T.; Noritomi, Pedro Y.; Silva, Jorge V. L.; Ruben, Rui B.Mandibular symphysis plates, used to heal fractures, can be made from different materials, normally titanium or CoCr alloys. In this work these two materials are tested and compared in order to study the plate's performance in fracture stabilization. This is a computational work performed with the advice of Brazilian maxoillofacial surgeons.
- Geometric and structural comparison of anatomic modelsPublication . Zeibak, R.; Freitas, D.; Almeida, H.A.; Bártolo, P.Computer Aided Design in the medical field helps translating CT and MRI data into anatomical 3D reconstructions. Accurate 3D models are valuable tools in several medical domains, thus finding accurate 3D reconstructions have profound advantages in all of the existing medical fields. The main objective of this research is to compare existing medical imaging processing softwares and evaluating their influence regarding both geometric deviations and numerical structural simulations between the 3D resulting models of both softwares.
- Automatic reconstruction of dental CT images using optimizationPublication . Amorim, Paulo H. J.; Moraes, Thiago F. de; Silva, Jorge V. L. da; Pedrini, Helio; Ruben, Rui B.Computed Tomography (CT) is, in several cases, important in dental diagnosis. In fact, the panoramic reconstruction is commonly used in order to have a longitudinal view of the dental arch. Nowadays, dental CT equipments emit lower-dose radiation compared with other CT machines. Thus, dental CT became popular. However, there are some equipments that are not able to make the panoramic reconstruction of the dental arch. In this work, a new method for automatically reconstructing the dental arch based in CT images is developed and discussed. The technique uses optimization methods in order to find the best B-spline that approaches the dental arch.
- Optimization of a perfusion bioreactor for tissue engineeringPublication . Freitas, D.; Almeida, H.A.; Bártolo, P.Tissue engineering aims to produce artificial tissue in order to create or repair the damage tissue. It is evident that scaffolds are of extreme importance, because they will be the support of the new tissue. This new tissue is cultivated in vitro in a bioreactor in which is placed the scaffold. In order to control the cell culture process inside of a bioreactor it is essential to know the fluid flow inside and around the scaffold and the respective wall shear stress. These wall shear stress must be adequate to the tissue to be cultivated, i.e., bone, muscle, cartilage and it is known that a proper stimulus is necessary to improve the cell proliferation inside the scaffold. This study consider a novel multifunctional bioreactor with a perfusion system module and it is intended to optimize the fluid flow within the scaffold and the respective wall shear stress on the scaffold.
- Distributions Families in Counting Bacteria for Compound SamplingPublication . Felgueiras, Miguel; Martins, João Paulo; Santos, RuiThe sensitivity and the specificity of a compound test depend on the distribution underlying the phenomenon. In this paper we consider count distributions unified under Panjer recursive formula and belonging to the Morris family, which verifies useful properties. The influence of the tail weight of the count distributions (that varies among infected and uninfected elements), evaluated in terms of the dispersion index, is investigated in the sensitivity and the specificity of the compound test.