793 resultados para Probabilistic Aggregation Criteria


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From the forest management perspective, many definitions have been proposed for the concept of forest sustainability. Despite this apparent diversity, most of them converge on the same aspects. In this work we developed a comparative approach of two distinct forest management methodologies used in Europe, more precisely in Slovenia and in Portugal. Although in each case study differences in vegetation, climate and pedological characteristics are evident, we were able to show some peculiar aspects of both the Slovenian and the Portuguese examples. This study also dealt with the evolution of the term sustainability in the last decades and how it played an important role for forest management options.

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Introduction and hypothesis Puborectalis avulsion is a likely etiological factor for female pelvic organ prolapse(FPOP). We performed a study to establish minimal sonographic criteria for the diagnosis of avulsion. Methods We analysed datasets of 764 women seen at a urogynecological service. Offline analysis of ultrasound datasets was performed blinded to patient data. Tomographic ultrasound imaging (TUI) was used to diagnose avulsion of the puborectalis muscle. Results Logistic regression modelling of TUI data showed that complete avulsion is best diagnosed by requiring the three central tomographic slices to be abnormal. This finding was obtained in 30% of patients and was associated with symptoms and signs of FPOP (P<0.001). Lesser degrees of trauma (‘partial avulsion’) were not associated with symptoms or signs of pelvic floor dysfunction. Conclusions Complete avulsion of the puborectalis muscle is best diagnosed on TUI by requiring all three central slices to be abnormal. Partial trauma seems of limited clinical relevance.

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Crowdsourcing innovation intermediaries are organizations that mediate the communication and relationship between companies that aspire to solve some problem or to take advantage of any business opportunity with a crowd that is prone to give ideas based on their knowledge, experience and wisdom. A significant part of the activity of these intermediaries is carried out by using a web platform that takes advantage of web 2.0 tools to implement its capabilities. Thus, ontologies are presented as an appropriate strategy to represent the knowledge inherent to this activity and therefore the accomplishment of interoperability between machines and systems. In this paper we present an ontology roadmap for developing crowdsourcing innovation ontology of the intermediation process. We start making a literature review on ontology building, analyze and compare ontologies that propose the development from scratch with the ones that propose reusing other ontologies, and present the criteria for selecting the methodology. We also review enterprise and innovation ontologies known in literature. Finally, are taken some conclusions and presented the roadmap for building crowdsourcing innovation intermediary ontology.

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The integration of wind power in eletricity generation brings new challenges to unit commitment due to the random nature of wind speed. For this particular optimisation problem, wind uncertainty has been handled in practice by means of conservative stochastic scenario-based optimisation models, or through additional operating reserve settings. However, generation companies may have different attitudes towards operating costs, load curtailment, or waste of wind energy, when considering the risk caused by wind power variability. Therefore, alternative and possibly more adequate approaches should be explored. This work is divided in two main parts. Firstly we survey the main formulations presented in the literature for the integration of wind power in the unit commitment problem (UCP) and present an alternative model for the wind-thermal unit commitment. We make use of the utility theory concepts to develop a multi-criteria stochastic model. The objectives considered are the minimisation of costs, load curtailment and waste of wind energy. Those are represented by individual utility functions and aggregated in a single additive utility function. This last function is adequately linearised leading to a mixed-integer linear program (MILP) model that can be tackled by general-purpose solvers in order to find the most preferred solution. In the second part we discuss the integration of pumped-storage hydro (PSH) units in the UCP with large wind penetration. Those units can provide extra flexibility by using wind energy to pump and store water in the form of potential energy that can be generated after during peak load periods. PSH units are added to the first model, yielding a MILP model with wind-hydro-thermal coordination. Results showed that the proposed methodology is able to reflect the risk profiles of decision makers for both models. By including PSH units, the results are significantly improved.

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INTRODUCTION: There is much controversy regarding the current indications and contraindications for digital replantation. PRESENTATION OF CASE: Three patients with absolute contraindications for digital replantation according to classical criteria are presented (Case 1: multilevel amputation of the hand and fingers; Case 3: avulsion of the thumb; Case 4: index amputation proximal to the insertion of the flexor digitorum superficialis). In addition a patient with a very distal digital amputation (Case 2), whose indication for replantation is controversial is also presented. In all cases, the patients were replanted and showed good functional and aesthetical results. DISCUSSION: Most authors advocate that the classical indications for replantation have been validated by experience, are predicated on the potential for long-term function, and should be followed in most if not all cases. However, some surgeons have been adopting a more liberal attitude with good results. CONCLUSION: The clinical cases presented in this paper suggest that the standard criteria for digital replantation should not be followed rigidly but instead should be regarded as a general guide.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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OBJECTIVE: Intensive image surveillance after endovascular aneurysm repair is generally recommended due to continued risk of complications. However, patients at lower risk may not benefit from this strategy. We evaluated the predictive value of the first postoperative computed tomography angiography (CTA) characteristics for aneurysm-related adverse events as a means of patient selection for risk-adapted surveillance. METHODS: All patients treated with the Low-Permeability Excluder Endoprosthesis (W. L. Gore & Assoc, Flagstaff, Ariz) at a tertiary institution from 2004 to 2011 were included. First postoperative CTAs were analyzed for the presence of endoleaks, endograft kinking, distance from the lowermost renal artery to the start of the endograft, and for proximal and distal sealing length using center lumen line reconstructions. The primary end point was freedom from aneurysm-related adverse events. Multivariable Cox regression was used to test postoperative CTA characteristics as independent risk factors, which were subsequently used as selection criteria for low-risk and high-risk groups. Estimates for freedom from adverse events were obtained using Kaplan-Meier survival curves. RESULTS: Included were 131 patients. The median follow-up was 4.1 years (interquartile range, 2.1-6.1). During this period, 30 patients (23%) sustained aneurysm-related adverse events. Seal length <10 mm and presence of endoleak were significant risk factors for this end point. Patients were subsequently categorized as low-risk (proximal and distal seal length ≥10 mm and no endoleak, n = 62) or high-risk (seal length <10 mm or presence of endoleak, or both; n = 69). During follow-up, four low-risk patients (3%) and 26 high-risk patients (19%) sustained events (P < .001). Four secondary interventions were required in three low-risk patients, and 31 secondary interventions in 23 high-risk patients. Sac growth was observed in two low-risk patients and in 15 high-risk patients. The 5-year estimates for freedom from aneurysm-related adverse events were 98% for the low-risk group and 52% for the high-risk group. For each diagnosis, 81.7 image examinations were necessary in the low-risk group and 8.2 in the high-risk group. CONCLUSIONS: Our results suggest that the first postoperative CTA provides important information for risk stratification after endovascular aneurysm repair when the Excluder endoprosthesis is used. In patients with adequate seal and no endoleaks, the risk of aneurysm-related adverse events was significantly reduced, resulting in a large number of unnecessary image examinations. Adjusting the imaging protocol beyond 30 days and up to 5 years, based on individual patients' risk, may result in a more efficient and rational postoperative surveillance.

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Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Informática, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

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RESUMO: Objetivo: Este trabalho teve como objetivo contribuir para o processo de adaptação cultural do Neck Disability Index (NDI), através da análise da sua unidimensionalidade e do estudo da sua fiabilidade (consistência interna e fiabilidade teste-reteste), validade de constructo e poder de resposta. De igual forma pretendeu-se caraterizar a intervenção realizada pela fisioterapia e os resultados obtidos em pacientes com Dor Cervical Crónica (DCC). Introdução: A dor cervical é um problema cada vez mais comum nos países industrializados, constituindo uma das três condições mais frequentemente reportadas por queixas de origem músculo-esquelética. A sua incidência é um fenómeno em crescimento, com custos implicados para a sociedade. Desta forma reconhece-se a importância de um instrumento que monitorize a evolução da incapacidade funcional associada à DCC. O NDI é atualmente o instrumento de avaliação mais recomendado para avaliar a incapacidade funcional associada à dor cervical. Foi traduzido e adaptado à língua portuguesa, mas à data não foi realizada nenhuma avaliação das suas propriedades psicométricas. Por outro lado, apesar de a literatura referir que os serviços de Fisioterapia são extremamente procurados por indivíduos com DCC, em Portugal, a informação sobre a sua prática nesta condição clínica é escassa ou mesmo inexistente. Assim, e sendo a incapacidade nas atividades funcionais uma das variáveis de maior impacto da DCC e ao mesmo tempo um dos resultados principais da intervenção da Fisioterapia, importa por um lado possuir instrumentos capazes de avaliar o nível de incapacidade funcional e a sua mudança, e por outro, aferir qual a intervenção realizada pela Fisioterapia e quais os resultados obtidos. Metodologia: Realizou-se um estudo de coorte prospetivo com uma amostra de conveniência, do tipo não probabilístico, constituída por 88 pacientes com DCC de origem músculo-esquelética e causa não traumática referenciados para 6 serviços de fisioterapia / medicina física e de reabilitação de clínicas e centros de reabilitação, sendo elegíveis todos os pacientes que cumprissem os critérios de inclusão e exclusão estabelecidos. Os pacientes foram avaliados em três momentos pré-definidos: antes do início das sessões de fisioterapia ou na 1ª semana de tratamento; 4 a 7 dias após a 1ª avaliação; e 7 semanas após o início da fisioterapia. Para verificação da unidimensionalidade do NDI, procedeu-se a uma Análise Fatorial Exploratória. As propriedades psicométricas do NDI avaliadas foram a Fiabilidade (consistência interna e fiabilidade teste-reteste), a Validade de Constructo e o Poder de Resposta. Posteriormente procedeu-se à caraterização da prática da fisioterapia quanto às modalidades utilizadas, número de sessões de tratamento e duração do episódio de cuidados. Adicionalmente descreveu-se os resultados obtidos após a intervenção da fisioterapia ao nível da dor e incapacidade. Resultados: os resultados obtidos foram positivos e significativos, com a confirmação da unidimensionalidade do NDI, sendo que em todos os critérios seguidos o fator mínimo retido foi de um. Na avaliação da consistência interna o valor obtido foi acima do mínimo aceitável (α Cronbach = 0,77), enquanto o valor de fiabilidade teste-reteste foi elevado (CCI =0,95). De igual forma, os resultados foram positivos para a validade de constructo, obtendo-se uma associação positiva do NDI com a Escala Numérica da dor (END). O valores de poder de resposta reportaram uma Área Abaixo da Curva de 0,63 (IC 95%=0,51-0,75), com valor de Diferença Mínima Clinicamente importante de 5,5 pontos (sensibilidade = 69,6%; especificidade = 43,6%). Relativamente á intervenção de fisioterapia em casos de DCC verificou-se que as características da prática da fisioterapia reportadas neste relatório são de difícil comparação ou análise dada a escassez ou inexistência de trabalhos publicados sobre este assunto em pacientes com DCC. No entanto, neste estudo, encontraram-se reduções significativas na intensidade da dor e incapacidade funcional após a intervenção de fisioterapia (z= -7,16; p<0,001 e t= 10,412, p<0,05, respetivamente). Conclusão: Os resultados do presente estudo revelam que o NDI-VP possui uma boa Fiabilidade, Validade de Constructo e Poder de Resposta. Revela ainda que a intervenção da fisioterapia em casos de DCC, apesar da escassez de trabalhos publicados, proporciona uma redução significativa dos níveis de dor e incapacidade em pacientes com DCC.--------------- ABSTRACT:Objective: the aim of this study was to contribute for the process of cultural adaption of the Neck Disability Index (NDI), through the analysis of his unidimensionality and the study of his reliability (internal consistency and test-retest reliability), construct validity and responsiveness. At the same time it pretends to characterize the intervention performed by physical therapy and the results in patients with Chronic Neck Pain (CNP). Introduction: neck pain is a common problem in the industrialized countries, since is one of the three most reported conditions by complaints with musculoskeletal origin. His incidence is a growth phenomena that implicate great costs to society. Therefore the importance of an instrument that monitories the evolution of the functional disability associated to CNP is recognized. Nowadays, NDI is the instrument most recommended to evaluate functional disability associated to neck pain. It has been translated and adapted to portuguese but, till now, no evaluation of his psychometric proprieties has been completed. In the other hand, despite literature refers that physical therapy services are extremely searched by patients with neck pain, in Portugal, the information about practice in this clinical condition is very few or inexistent. Therefore, and since disability in the functional activities is one of the variables with most impact of CNP and, at the same time, one of the main results of physical therapy interventions, it’s important to have instruments capable of evaluate the level of functional disability and his change, and also calculate which intervention of physical therapy is most appropriate and his results. Methodology: it was used a prospective cohort study with a convenience sample, non-probabilistic, consisting of 88 patients with CNP of musculoskeletal origin and non-traumatic cause, referred to 6 physical therapy services of clinics and rehabilitation centers, and fulfilled the inclusion and exclusion criteria established. Patients were evaluated in three pre-defined moments: before the beginning of physical therapy or during the first week of treatment; 4 to 7 days after the first evaluation; and 7 weeks after beginning of physical therapy. To verify NDI unidimensionality, we run an Exploratory Factorial Analysis. NDI psychometric proprieties evaluated were reliability (internal consistency and test-retest reliability), construct validity and responsiveness. Subsequently, it was proceeded the characterization the practice of physical therapy regarding to the modalities used, the number of treatment sessions and duration of the episode of care. Additionally it was described the results obtained after the intervention of the physical therapy, the level of pain and the disability. Results: results were positive and significant, with the confirmation of the NDI unidimensionality, since in every followed criteria the minimal retained factor was one. In the evaluation of internal consistency the value was above the minimal accepted (α Cronbach = 0,77), and the test-retest reliability value was high (CCI =0,95). Results were positive to construct validity, with an positive association of the NDI with Numeric Rating Scale (NRS). Responsiveness values reported an Area Under Curve (AUC) of 0,63 (IC 95%=0,51-0,75) with a Minimal Important Detectable Change (MIDC) of 5,5 points (sensitivity = 69,9%; specificity = 43,6%). Regarding physical therapy interventions in CNP, it was verified that the physical therapy characteristics reported are difficult to compare or analyze since there are very few published studies about this topic. However, in this study, significant reductions were founded in pain intensity and functional disability after intervention(z= -7,16; p<0,001 and t= 10,412, p<0,05, respectively).Conclusion: present study results reveals that NDI has an good reliability, construct validity and responsiveness. It also reveals that physical therapy intervention in CNP, beside few studies published, result in a significant reduction of pain and disability levels in patients with CNP.

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Dissertação para obtenção do Grau de Mestre em Engenharia Informática

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Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

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This work studies the combination of safe and probabilistic reasoning through the hybridization of Monte Carlo integration techniques with continuous constraint programming. In continuous constraint programming there are variables ranging over continuous domains (represented as intervals) together with constraints over them (relations between variables) and the goal is to find values for those variables that satisfy all the constraints (consistent scenarios). Constraint programming “branch-and-prune” algorithms produce safe enclosures of all consistent scenarios. Special proposed algorithms for probabilistic constraint reasoning compute the probability of sets of consistent scenarios which imply the calculation of an integral over these sets (quadrature). In this work we propose to extend the “branch-and-prune” algorithms with Monte Carlo integration techniques to compute such probabilities. This approach can be useful in robotics for localization problems. Traditional approaches are based on probabilistic techniques that search the most likely scenario, which may not satisfy the model constraints. We show how to apply our approach in order to cope with this problem and provide functionality in real time.

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The European Court of Justice has held that as from 21 December 2012 insurers may no longer charge men and women differently on the basis of scientific evidence that is statistically linked to their sex, effectively prohibiting the use of sex as a factor in the calculation of premiums and benefits for the purposes of insurance and related financial services throughout the European Union. This ruling marks a sharp turn away from the traditional view that insurers should be allowed to apply just about any risk assessment criterion, so long as it is sustained by the findings of actuarial science. The naïveté behind the assumption that insurers’ recourse to statistical data and probabilistic analysis, given their scientific nature, would suffice to keep them out of harm’s way was exposed. In this article I look at the flaws of this assumption and question whether this judicial decision, whilst constituting a most welcome landmark in the pursuit of equality between men and women, has nonetheless gone too far by saying too little on the million dollar question of what separates admissible criteria of differentiation from inadmissible forms of discrimination.

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The assessment of existing timber structures is often limited to information obtained from non or semi destructive testing, as mechanical testing is in many cases not possible due to its destructive nature. Therefore, the available data provides only an indirect measurement of the reference mechanical properties of timber elements, often obtained through empirical based correlations. Moreover, the data must result from the combination of different tests, as to provide a reliable source of information for a structural analysis. Even if general guidelines are available for each typology of testing, there is still a need for a global methodology allowing to combine information from different sources and infer upon that information in a decision process. In this scope, the present work presents the implementation of a probabilistic based framework for safety assessment of existing timber elements. This methodology combines information gathered in different scales and follows a probabilistic framework allowing for the structural assessment of existing timber elements with possibility of inference and updating of its mechanical properties, through Bayesian methods. The probabilistic based framework is based in four main steps: (i) scale of information; (ii) measurement data; (iii) probability assignment; and (iv) structural analysis. In this work, the proposed methodology is implemented in a case study. Data was obtained through a multi-scale experimental campaign made to old chestnut timber beams accounting correlations of non and semi-destructive tests with mechanical properties. Finally, different inference scenarios are discussed aiming at the characterization of the safety level of the elements.