987 resultados para III-posed inverse problem


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Dissertation presented to obtain a PhD degree in Biochemistry at the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa

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Parallel hyperspectral unmixing problem is considered in this paper. A semisupervised approach is developed under the linear mixture model, where the abundance's physical constraints are taken into account. The proposed approach relies on the increasing availability of spectral libraries of materials measured on the ground instead of resorting to endmember extraction methods. Since Libraries are potentially very large and hyperspectral datasets are of high dimensionality a parallel implementation in a pixel-by-pixel fashion is derived to properly exploits the graphics processing units (GPU) architecture at low level, thus taking full advantage of the computational power of GPUs. Experimental results obtained for real hyperspectral datasets reveal significant speedup factors, up to 164 times, with regards to optimized serial implementation.

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Two serological surveys for Chagas' infection were carried out, in 1991 and 1993, respectively, using a conglomerate family samples from the residents in the town of Barcelos (in the northern part of the State of Amazonas, on the right bank of the Rio Negro, 490 Km up-river from Manaus), using indirect immunofluorescent tests for anti-T. cruzi antibodies. In the first survey (1991), 628 blood samples from the residents of 142 dwellings were tested, showing positive in 12.7% for anti-T. cruzi antibodies and in 1993 an other 658 samples from residents of 171 dwellings showed positive in 13.7% of the tests, thus confirming the previous results. From 170 individuals with positive serology for T. cruzi antibodies, 112 (66%) were interviewed and submitted to electrocardiographic and clinical examinations; 82 (73.2%) of them gave consent for xenodiagnosis. From the 112 interviewed 52 (46.4%) recognized the triatomines as "piaçavas' lice", 48 (42.8%) knew the bugs from their work places being gatherers of piaçava fibers in rural areas and 19 (16.9%) said that have been bitten by bugs in their huts. Only 2 (2.4%) of 82 xenodiagnosis applied were positive for T. cruzi and 9 (8%) of the ECG had alterations compatible with Chagas' disease.

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O primeiro objetivo deste relatório, que adiante se desenvolve, é apresentar o trabalho realizado para a obtenção de conhecimentos que justifiquem a atribuição do grau de mestre em engenharia, no ramo das construções. O estágio, que a este trabalho dá sustentação, foi feito na empresa Metaloviana, onde foi possível acompanhar as várias fases de conceção, fabrico e montagem de um teto falso, designadamente na sala de comando da central Venda Nova III, de aproveitamento hidroelétrico. Tendo Portugal objetivos cada vez mais ambiciosos na utilização de energias renováveis, aproveitando, entre outros, os recursos hídricos para a produção de eletricidade, a EDP Produção fez estudos onde verificou que a realização de reforços de potência em aproveitamento já existentes, seria uma forma economicamente bastante atrativa e ao mesmo tempo responderia às crescentes solicitações energéticas. É neste âmbito que se insere o Reforço de Potência em Venda Nova III. A empresa Metaloviana, com instalações fabris em Viana do Castelo, tem todo um historial e capacidade, reconhecida nacional e internacionalmente. Este, confere a certeza de ter acompanhado um trabalho de ponta, devidamente creditado e fundamentado numa qualidade e mérito, por demais reconhecido.

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From 1950 to 1990 a total of 45,862 strains (31,517 isolates from human sources, and 14,345 of non-human origin) were identified at Instituto Adolfo Lutz. No prevalence of any serovars was seen during the period 1950-66 among human sources isolates. Important changing pattern was seen in 1968, when S. Typhimurim surprisingly increased becoming the prevalent serovar in the following decades. During the period of 1970-76, S. Typhimurium represented 77.7% of all serovars of human origin. Significant rise in S. Agona isolation as well as in the number of different serovars among human sources strains were seen in the late 70' and the 80's. More than one hundred different serovars were identified among non-human origin strains. Among serovars isolated from human sources, 74.9%, 15.5%, and 3.7% were recovered from stool, blood, and cerebrospinal fluid cultures, respectively. The outbreak of meningitis by S. Grumpensis in the 60's, emphasizes the concept that any Salmonella serovars can be a cause of epidemics, mainly of the nosocomial origin. This evaluation covering a long period shows the important role of the Public Health Laboratory in the surveillance of salmonellosis, one of the most frequent zoonosis in the world.

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Proceedings of the Edinburgh Mathematical Society, nº50 (2007), p.551-561

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The minimum interval graph completion problem consists of, given a graph G = ( V, E ), finding a supergraph H = ( V, E ∪ F ) that is an interval graph, while adding the least number of edges |F| . We present an integer programming formulation for solving the minimum interval graph completion problem recurring to a characteri- zation of interval graphs that produces a linear ordering of the maximal cliques of the solution graph.

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In this paper we address an order processing optimization problem known as minimization of open stacks (MOSP). We present an integer pro gramming model, based on the existence of a perfect elimination scheme in interval graphs, which finds an optimal sequence for the costumers orders.

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The Basel Committee on Banking Supervision (BCBS) introduced new regulations for banking supervision in December 2010, better known as Basel III recommendations that aimed at guaranteeing the solidity of banks worldwide and the mitigation of new banking crises risks. The European Union transposed these directives through the Credit Review Directives IV (CRD IV). Portugal adopted CRD IV by a new decree-law no. 157/2014, on 24 th October 2014, enforced from 24 th November 2014. While individual banks have been given the option of using the internal ratings based method, this study analyses the compliance levels of all Portuguese banking institutions using the standard method, also prescribed by BCBS. Our results show that out of thirteen banks on 31-12-2013 only five banks were in a comfortable position and the remaining eight could not reach the minimum requirements set up by BCBS for 1-1-2014.

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WWW is a huge, open, heterogeneous system, however its contents data is mainly human oriented. The Semantic Web needs to assure that data is readable and “understandable” to intelligent software agents, though the use of explicit and formal semantics. Ontologies constitute a privileged artifact for capturing the semantic of the WWW data. Temporal and spatial dimensions are transversal to the generality of knowledge domains and therefore are fundamental for the reasoning process of software agents. Representing temporal/spatial evolution of concepts and their relations in OWL (W3C standard for ontologies) it is not straightforward. Although proposed several strategies to tackle this problem but there is still no formal and standard approach. This work main goal consists of development of methods/tools to support the engineering of temporal and spatial aspects in intelligent systems through the use of OWL ontologies. An existing method for ontology engineering, Fonte was used as framework for the development of this work. As main contributions of this work Fonte was re-engineered in order to: i) support the spatial dimension; ii) work with OWL Ontologies; iii) and support the application of Ontology Design Patterns. Finally, the capabilities of the proposed approach were demonstrated by engineering time and space in a demo ontology about football.

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This study was conducted to assess the presence of schistosomiasis mansoni in the "Noroeste de Minas" mesoregion, an area considered non-endemic. A malacologic survey and parasitologic stool examinations were undertaken in 13 municipalities of the mesoregion. A sample of 3,283 primary school students was submitted to fecal examination by the Kato-Katz method. A total of 3,627 planorbids was collected and examined. The molluscs were identified as Biomphalaria straminea in seven municipalities (Unaí, Bonfinópolis de Minas, Paracatu, João Pinheiro, Vazante, Lagamar and Lagoa Grande) and as Biomphalaria peregrina in one (Presidente Olegário). All planorbids were negative for Schistosoma mansoni. Four students were diagnosed with schistosomiasis in the municipalities of Buritis, Formoso, Paracatu and Unaí, but none of these cases was considered autochthonous. The data obtained indicate that the "Noroeste de Minas" mesoregion continues to be non-endemic for schistosomiasis mansoni, although the presence of intermediate hosts associated with parasitized individuals emphasizes the need for epidemiological surveillance of schistosomiasis in this mesoregion.

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The CDIO Initiative is an open innovative educational framework for engineering graduation degrees set in the context of Conceiving – Designing – Implementing – Operating real-world systems and products, which is embraced by a network of worldwide universities, the CDIO collaborators. A CDIO compliant engineering degree programme typically includes a capstone module on the final semester. Its purpose is to expose students to problems of a greater dimension and complexity than those faced throughout the degree programme as well as to put them in contact with the so-called real world, in opposition to the academic world. However, even in the CDIO context, there are barriers that separate engineering capstone students from the real world context of an engineering professional: (i) limited interaction with experts from diverse scientific areas; (ii) reduced cultural and scientific diversity within the teams; and (iii) lack of a project supportive framework to foster the complementary technical and non-technical skills required in an engineering professional. To address these shortcomings, we propose the adoption of the European Project Semester (EPS) framework, a one semester student centred international capstone programme offered by a group of European engineering schools (the EPS Providers) as part of their student exchange programme portfolio. The EPS package is organised around a central module – the EPS project – and a set of complementary supportive modules. Project proposals refer to open multidisciplinary real world problems and supervision becomes coaching. The students are organised in teams, grouping individuals from diverse academic backgrounds and nationalities, and each team is fully responsible for conducting its project. EPS complies with the CDIO directives on Design-Implement experiences and provides an integrated framework for undertaking capstone projects, which is focussed on multicultural and multidisciplinary teamwork, problem-solving, communication, creativity, leadership, entrepreneurship, ethical reasoning and global contextual analysis. As a result, we recommend the adoption of the EPS within CDIO capstone modules for the benefit of engineering students.

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Near real time media content personalisation is nowadays a major challenge involving media content sources, distributors and viewers. This paper describes an approach to seamless recommendation, negotiation and transaction of personalised media content. It adopts an integrated view of the problem by proposing, on the business-to-business (B2B) side, a brokerage platform to negotiate the media items on behalf of the media content distributors and sources, providing viewers, on the business-to-consumer (B2C) side, with a personalised electronic programme guide (EPG) containing the set of recommended items after negotiation. In this setup, when a viewer connects, the distributor looks up and invites sources to negotiate the contents of the viewer personal EPG. The proposed multi-agent brokerage platform is structured in four layers, modelling the registration, service agreement, partner lookup, invitation as well as item recommendation, negotiation and transaction stages of the B2B processes. The recommendation service is a rule-based switch hybrid filter, including six collaborative and two content-based filters. The rule-based system selects, at runtime, the filter(s) to apply as well as the final set of recommendations to present. The filter selection is based on the data available, ranging from the history of items watched to the ratings and/or tags assigned to the items by the viewer. Additionally, this module implements (i) a novel item stereotype to represent newly arrived items, (ii) a standard user stereotype for new users, (iii) a novel passive user tag cloud stereotype for socially passive users, and (iv) a new content-based filter named the collinearity and proximity similarity (CPS). At the end of the paper, we present off-line results and a case study describing how the recommendation service works. The proposed system provides, to our knowledge, an excellent holistic solution to the problem of recommending multimedia contents.

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The European Union Emissions Trading Scheme (EU ETS) is a cornerstone of the European Union's policy to combat climate change and its key tool for reducing industrial greenhouse gas emissions cost-effectively. The purpose of the present work is to evaluate the influence of CO2 opportunity cost on the Spanish wholesale electricity price. Our sample includes all Phase II of the EU ETS and the first year of Phase III implementation, from January 2008 to December 2013. A vector error correction model (VECM) is applied to estimate not only long-run equilibrium relations, but also short-run interactions between the electricity price and the fuel (natural gas and coal) and carbon prices. The four commodities prices are modeled as joint endogenous variables with air temperature and renewable energy as exogenous variables. We found a long-run relationship (cointegration) between electricity price, carbon price, and fuel prices. By estimating the dynamic pass-through of carbon price into electricity price for different periods of our sample, it is possible to observe the weakening of the link between carbon and electricity prices as a result from the collapse on CO2 prices, therefore compromising the efficacy of the system to reach proposed environmental goals. This conclusion is in line with the need to shape new policies within the framework of the EU ETS that prevent excessive low prices for carbon over extended periods of time.

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Many-core platforms are an emerging technology in the real-time embedded domain. These devices offer various options for power savings, cost reductions and contribute to the overall system flexibility, however, issues such as unpredictability, scalability and analysis pessimism are serious challenges to their integration into the aforementioned area. The focus of this work is on many-core platforms using a limited migrative model (LMM). LMM is an approach based on the fundamental concepts of the multi-kernel paradigm, which is a promising step towards scalable and predictable many-cores. In this work, we formulate the problem of real-time application mapping on a many-core platform using LMM, and propose a three-stage method to solve it. An extended version of the existing analysis is used to assure that derived mappings (i) guarantee the fulfilment of timing constraints posed on worst-case communication delays of individual applications, and (ii) provide an environment to perform load balancing for e.g. energy/thermal management, fault tolerance and/or performance reasons.