Coralliophila occidentale Kosuge et Fernandes, 1988

Catálogo do Museo de Historia Natural USC. n. inventario 10014

Estimating the performance of mimo sc-fde systems using siso measurements

project 023304 UIDB/50008/2020The demand for ubiquitous telecommunications services forces operators to have a special concern about signal quality and the coverage area they offer to their customers. This was usually checked by using suitable propagation models for Single Input Single Output (SISO) systems, which are no longer the case for new and future mobile generations, such as 5G and beyond. To guarantee good signal quality coverage, operators started to replace these models with Multiple Input Multiple Output (MIMO) ones. To achieve the best results, these models are usually calibrated with Drive Test (DT) measures; however, the DTs available for MIMO propagation models are sparse, in contrast to SISO ones. The main contribution presented in this paper is a methodology to extend the propagation models of SISO systems so they can be applied in MIMO sytems with Single-Carrier and Frequency-Domain Equalization (SC-FDE), while still using DTs acquired for SISO systems. This paper presents the impact on Bit Error Rate (BER) performance and its coverage area resulting from the application of our proposed method. We consider a MIMO SC-FDE system with an Iterative Block Decision Feedback Equalization (IB-DFE) receiver and we present the improvement expressions for the BER that we illustrate with some simulations.publishersversionpublishe

Verifying design plans and detecting deficiencies in concrete bridge using GPR

During the construction of concrete structures such as bridges, many deficiencies may occur due to an incorrect application or changes in the original design plans and construction errors. Frequently, areas with very poorly vibrated concrete, insufficiently grouted tendon ducts and incorrectly positioned reinforcement bars appear. Thus, the detection of these construction deficiencies is essential to prevent further damage to the bridge. Subsequently, a concrete specimen was prepared aimed at simulating some of the problems that can occur during the construction. The specimen was then mapped using a GPR system to check the effectiveness of this tool to provide information about those deficiencies. The acquisition was carried out in reflection mode and the results were further processed using 3D reconstruction software in order to obtain a more realistic and comprehensible image. These measurements showed rather good results. The 3D image provided much more detailed information about the elements placed inside the specimen relatively to 2D radargrams, which are generally used for primary target identification.Fundação para a Ciência e a Tecnologia (FCT) - POCTI SFRH/BD/6409/2001.Sustainable Bridges” European project FP6-PLT-0165

Utilização do radar de prospecção geotécnica na localização das bainhas de pré-esforço nas pontes da Barra e Lanheses

Algumas pontes de betão armado, em serviço há mais de 30 anos, apresentam, actualmente, elevados índices de deterioração, que têm levado as entidades a proceder à sua beneficiação e reforço estrutural. Neste artigo, o georadar é utilizado para localizar elementos estruturais fundamentais à segurança de duas pontes de betão armado, que doutra maneira, poderiam ser danificadas e, assim, por em causa a segurança das mesmas.União Europeia (UE) - Projecto “Sustainable Bridges” - FP6-PLT-01653

Diabetic Mastopathy: a Case Report

Diabetic mastopathy (DMP) is an uncommon collection of clinical, radiological, and histological features, classically described in premenopausal women with long-term insulin-dependent diabetes mellitus. This entity can mimic breast carcinoma, but, in the appropriate clinical and imaging setting, the diagnosis can be made by core biopsy, avoiding unnecessary surgeries. We report the case of a 34-year-old female, with a 12-year history of type 1 diabetes, who presented with bilateral breast lumps. Mammography, ultrasonography, and magnetic resonance imaging could not exclude the suspicion of malignancy, and a core biopsy was performed showing the typical histologic features of DMP. The literature is briefly reviewed

Comparison of Artificial Intelligence and Semi-Empirical Methodologies for Estimation of Coverage in Mobile Networks

Project 023304 UIDB/04111/2020To help telecommunication operators in their network planning, namely coverage estimation and optimisation tasks, this article presents a comparison between a semi-empirical propagation model and a propagation model generated using Artificial Intelligence (AI). These two types of propagation models are quite different in their design. The semi-empiric Automatically Calibrated Standard Propagation Model (ACSPM) is specific for an operating antenna, being calibrated every time a use case application is used and the Artificial Intelligence Propagation Model (AIPM) can be applied in different scenarios, once trained, allowing to estimate coverage for a new antenna location, using information from neighboring antennas. These models have quite different features and applicability. The ACSPM should be applied in network optimisation, when using data from the current state of the antennas. The AIPM can be used in the deployment of new antennas, as it uses data from a certain geographical area. For a better comparison of the models studied, extensive Drive Tests (DT) collection campaigns conducted by operators are used, since coverage estimations are more realistic when DTs are considered. Both models are generated using very different methodologies, but their resulting performance is very similar. The AIPM achieves a Mean Absolute Error (MAE) up to 6.1 dB with a standard deviation of 4 dB. When compared to the ACSPM we have an improvement of 0.5 dB, since this only achieves a MAE up to 6.6 dB. AIPM achieves better results and is the characterised for being completely agnostic and definition-free, when compared with known propagation models.publishersversionpublishe

Cloud-Based Implementation of an Automatic Coverage Estimation Methodology for Self-Organising Network

UIDB/EEA/50008/2020One of the main concerns of telecommunications operators is related to network coverage. A weak coverage can lead to a performance decrease, not only in the user experience, when using the operators' services, such as multimedia streaming, but also in the overall Quality of Service. This paper presents a novel cloud-based framework of a semi-empirical propagation model that estimates the coverage in a precise way. The novelty of this model is that it is automatically calibrated by using drive test measurements, terrain morphology, buildings in the area, configurations of the network itself and key performance indicators, automatically extracted from the operator's network. Requirements and use cases are presented as motivations for this methodology. The results achieve an accuracy of about 5 dB, allowing operators to obtain accurate neighbour lists, optimise network planning and automate certain actions on the network by enabling the Self-Organising Network concept. The cloud implementation enables a fast and easy integration with other network management and monitoring tools, such as the Metric platform, optimising operators' resource usage recurring to elastic resources on-demand when needed. This implementation was integrated into the Metric platform, which is currently available to be used by several operators.publishersversionpublishe

Natural establishment of Eucalyptus globulus Labill. in burnt stands in Portugal

Exotic tree species are increasingly common in many regions of the world and at least some species are becoming naturalized in the regions where they were introduced. Disturbances like fire may be at the origin or accelerate the naturalization of these species. Portugal holds one of the largest areas of exotic Eucalyptus globulus plantations in the world and is one of the countries most affected by forest fires. These two facts have triggered the present research. This study aimed at characterising medium-term natural establishment of E. globulus plants originated from seeds under natural conditions in burnt planted forests (pure E. globulus stands, pure Pinus pinaster stands, and mixed stands of both species), and at analysing factors associated with this establishment. Occurrence, abundance and height of naturally established E. globulus plants were characterized in 284 sites distributed in burnt areas, across Central and Northern Portugal, 5– 7 years after wildfire. Generalized linear models were used to assess the influence of stand type, regional productivity potential, and post-fire management practices on occurrence probability, density, and median height of sampled E. globulus individuals. The influence of these explanatory variables on the structure (in terms of size class distribution) of naturally established E. globulus cohort was examined using analysis of similarity and non-metric multidimensional scaling. Naturally established E. globulus plants were present in 93.1%, 19.0% and 98.6% of samples in pure E. globulus, pure P. pinaster and mixed stands, respectively. Cohort median density was 0.20 plants m 2 and maximum density was 4.55 plants m 2. Median height of plantswas 2.0 mand 95.3% of them had h >1.30 mand DBH 65 cm. Establishment probability, density and median height were highest in the most productive regions. Three post-fire management operations had a significant influence on the response variables: (i) salvage logging was associated with a higher density; (ii) tillage was associated with a lower density and a smaller median height; (iii) understorey removal was associated with a lower occurrence probability. Tillage was the only studied factor influencing the size structure of spontaneously established cohort, eliminating larger plants. This study showed that stand type, productivity region and post-fire management operations might have significantly influenced the natural establishment of E. globulus in burnt areas, and consequently the species naturalization process in Portugal. The implications of these findings for management are discussedinfo:eu-repo/semantics/publishedVersio

Application of radar techniques to the verification of design plans and the detection of defects in concrete bridges

Non-destructive tests (NDT) are an essential tool used in special inspections to gather detailed information about the condition of a bridge. The inspection of bridge decks is a critical task, and, currently, can be successfully carried out using a wide range of NDT techniques. Nevertheless, some of these techniques are excessively expensive and time consuming. One of these techniques, the ground penetrating radar (GPR), has been used for some decades in the non-destructive inspection and diagnosis of concrete bridges. GPR is useful to find general information about the true position of reinforcement and tendon ducts, and check the quality of the construction and materials. A significant number of reinforced and prestressed concrete bridges are deteriorating at a rapid rate and need to be repaired and strengthened. During these rehabilitation processes, designers are often faced with a lack of original design plans and unawareness of the real position of reinforcement and tendon ducts. In this paper, three case studies of the use of GPR techniques for the inspection of concrete bridges are presented and analysed. The main aim of this research is to show the strong need and usefulness of these techniques, which can provide non-visible information about structural geometry and integrity required for strengthening and rehabilitation purposes.L. T. would like to acknowledge the support from the 'Sustainable Bridges' European project, grant number FP6-PLT-01653 (www.sustainablebridges.net). F. M. F. acknowledges the partial funding of this work by the FCT through the scholarship POCTI SFRH/BPD/26706/2005