929 resultados para System reliability index


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Dissertação de Mestrado, Estudos Integrados dos Oceanos, 15 de Março de 2016, Universidade dos Açores.

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This thesis presents the Fuzzy Monte Carlo Model for Transmission Power Systems Reliability based studies (FMC-TRel) methodology, which is based on statistical failure and repair data of the transmission power system components and uses fuzzyprobabilistic modeling for system component outage parameters. Using statistical records allows developing the fuzzy membership functions of system component outage parameters. The proposed hybrid method of fuzzy set and Monte Carlo simulation based on the fuzzy-probabilistic models allows catching both randomness and fuzziness of component outage parameters. A network contingency analysis to identify any overloading or voltage violation in the network is performed once obtained the system states. This is followed by a remedial action algorithm, based on Optimal Power Flow, to reschedule generations and alleviate constraint violations and, at the same time, to avoid any load curtailment, if possible, or, otherwise, to minimize the total load curtailment, for the states identified by the contingency analysis. For the system states that cause load curtailment, an optimization approach is applied to reduce the probability of occurrence of these states while minimizing the costs to achieve that reduction. This methodology is of most importance for supporting the transmission system operator decision making, namely in the identification of critical components and in the planning of future investments in the transmission power system. A case study based on Reliability Test System (RTS) 1996 IEEE 24 Bus is presented to illustrate with detail the application of the proposed methodology.

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OBJECTIVE: To analyze reliability of a self-applied questionnaire on substance use and misuse among adolescent students. METHODS: Two cross-sectional studies were carried out for the instrument test-retest. The sample comprised male and female students aged 1119 years from public and private schools (elementary, middle, and high school students) in the city of Salvador, Northeastern Brazil, in 2006. A total of 591 questionnaires were applied in the test and 467 in the retest. Descriptive statistics, the Kappa index, Cronbach's alpha and intraclass correlation were estimated. RESULTS: The prevalence of substance use/misuse was similar in both test and retest. Sociodemographic variables showed a "moderate" to "almost perfect" agreement for the Kappa index, and a "satisfactory" (>0.75) consistency for Cronbach's alpha and intraclass correlation. The age which psychoactive substances (tobacco, alcohol, and cannabis) were first used and chronological age were similar in both studies. Test-retest reliability was found to be a good indicator of students' age of initiation and their patterns of substance use. CONCLUSIONS: The questionnaire reliability was found to be satisfactory in the population studied.

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The discovery of X-rays was undoubtedly one of the greatest stimulus for improving the efficiency in the provision of healthcare services. The ability to view, non-invasively, inside the human body has greatly facilitated the work of professionals in diagnosis of diseases. The exclusive focus on image quality (IQ), without understanding how they are obtained, affect negatively the efficiency in diagnostic radiology. The equilibrium between the benefits and the risks are often forgotten. It is necessary to adopt optimization strategies to maximize the benefits (image quality) and minimize risk (dose to the patient) in radiological facilities. In radiology, the implementation of optimization strategies involves an understanding of images acquisition process. When a radiographer adopts a certain value of a parameter (tube potential [kVp], tube current-exposure time product [mAs] or additional filtration), it is essential to know its meaning and impact of their variation in dose and image quality. Without this, any optimization strategy will be a failure. Worldwide, data show that use of x-rays has been increasingly frequent. In Cabo Verde, we note an effort by healthcare institutions (e.g. Ministry of Health) in equipping radiological facilities and the recent installation of a telemedicine system requires purchase of new radiological equipment. In addition, the transition from screen-films to digital systems is characterized by a raise in patient exposure. Given that this transition is slower in less developed countries, as is the case of Cabo Verde, the need to adopt optimization strategies becomes increasingly necessary. This study was conducted as an attempt to answer that need. Although this work is about objective evaluation of image quality, and in medical practice the evaluation is usually subjective (visual evaluation of images by radiographer / radiologist), studies reported a correlation between these two types of evaluation (objective and subjective) [5-7] which accredits for conducting such studies. The purpose of this study is to evaluate the effect of exposure parameters (kVp and mAs) when using additional Cooper (Cu) filtration in dose and image quality in a Computed Radiography system.

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

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ABSTRACT OBJECTIVE To validate a Spanish version of the Test of Gross Motor Development (TGMD-2) for the Chilean population. METHODS Descriptive, transversal, non-experimental validity and reliability study. Four translators, three experts and 92 Chilean children, from five to 10 years, students from a primary school in Santiago, Chile, have participated. The Committee of Experts has carried out translation, back-translation and revision processes to determine the translinguistic equivalence and content validity of the test, using the content validity index in 2013. In addition, a pilot implementation was achieved to determine test reliability in Spanish, by using the intraclass correlation coefficient and Bland-Altman method. We evaluated whether the results presented significant differences by replacing the bat with a racket, using T-test. RESULTS We obtained a content validity index higher than 0.80 for language clarity and relevance of the TGMD-2 for children. There were significant differences in the object control subtest when comparing the results with bat and racket. The intraclass correlation coefficient for reliability inter-rater, intra-rater and test-retest reliability was greater than 0.80 in all cases. CONCLUSIONS The TGMD-2 has appropriate content validity to be applied in the Chilean population. The reliability of this test is within the appropriate parameters and its use could be recommended in this population after the establishment of normative data, setting a further precedent for the validation in other Latin American countries.

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OBJECTIVE To analyze if size, administrative level, legal status, type of unit and educational activity influence the hospital network performance in providing services to the Brazilian Unified Health System.METHODS This cross-sectional study evaluated data from the Hospital Information System and the Cadastro Nacional de Estabelecimentos de Saúde (National Registry of Health Facilities), 2012, in Sao Paulo, Southeastern Brazil. We calculated performance indicators, such as: the ratio of hospital employees per bed; mean amount paid for admission; bed occupancy rate; average length of stay; bed turnover index and hospital mortality rate. Data were expressed as mean and standard deviation. The groups were compared using analysis of variance (ANOVA) and Bonferroni correction.RESULTS The hospital occupancy rate in small hospitals was lower than in medium, big and special-sized hospitals. Higher hospital occupancy rate and bed turnover index were observed in hospitals that include education in their activities. The hospital mortality rate was lower in specialized hospitals compared to general ones, despite their higher proportion of highly complex admissions. We found no differences between hospitals in the direct and indirect administration for most of the indicators analyzed.CONCLUSIONS The study indicated the importance of the scale effect on efficiency, and larger hospitals had a higher performance. Hospitals that include education in their activities had a higher operating performance, albeit with associated importance of using human resources and highly complex structures. Specialized hospitals had a significantly lower rate of mortality than general hospitals, indicating the positive effect of the volume of procedures and technology used on clinical outcomes. The analysis related to the administrative level and legal status did not show any significant performance differences between the categories of public hospitals.

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Dynamically reconfigurable SRAM-based field-programmable gate arrays (FPGAs) enable the implementation of reconfigurable computing systems where several applications may be run simultaneously, sharing the available resources according to their own immediate functional requirements. To exclude malfunctioning due to faulty elements, the reliability of all FPGA resources must be guaranteed. Since resource allocation takes place asynchronously, an online structural test scheme is the only way of ensuring reliable system operation. On the other hand, this test scheme should not disturb the operation of the circuit, otherwise availability would be compromised. System performance is also influenced by the efficiency of the management strategies that must be able to dynamically allocate enough resources when requested by each application. As those resources are allocated and later released, many small free resource blocks are created, which are left unused due to performance and routing restrictions. To avoid wasting logic resources, the FPGA logic space must be defragmented regularly. This paper presents a non-intrusive active replication procedure that supports the proposed test methodology and the implementation of defragmentation strategies, assuring both the availability of resources and their perfect working condition, without disturbing system operation.

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Este artigo pretende descrever vários aspetos da segregação, integração e inclusão dentro do sistema educativo obrigatório austríaco. Após uma introdução que contém definições e um resumo internacional, será brevemente descrito o sistema educativo da Áustria. Subsequentemente, três temas de interesse serão debatidos. Primeiro será caracterizada a situação atual referente à inclusão de crianças com necessidades educativas especiais. Esta situação difere bastante entre estados federais. Serão descritos os desenvolvimentos que conduziram à situação atual. Em segundo serão apresentados estudos empíricos recentes relativos ao movimento austríaco que almeja a inclusão. Em terceiro e a título exemplificativo serão apresentados em detalhe alguns desenvolvimentos recentes, alguns planos e visões futuras de três estados federais austríacos.

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Tese para a obtenção do grau de Doutor em Economia, especialidade de Economia da Empresa

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The shifted Legendre orthogonal polynomials are used for the numerical solution of a new formulation for the multi-dimensional fractional optimal control problem (M-DFOCP) with a quadratic performance index. The fractional derivatives are described in the Caputo sense. The Lagrange multiplier method for the constrained extremum and the operational matrix of fractional integrals are used together with the help of the properties of the shifted Legendre orthonormal polynomials. The method reduces the M-DFOCP to a simpler problem that consists of solving a system of algebraic equations. For confirming the efficiency and accuracy of the proposed scheme, some test problems are implemented with their approximate solutions.

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Since there are no studies evaluating the participation of the complement system (CS) in Jorge Lobo's disease and its activity on the fungus Lacazia loboi, we carried out the present investigation. Fungal cells with a viability index of 48% were obtained from the footpads of BALB/c mice and incubated with a pool of inactivated serum from patients with the mycosis or with sterile saline for 30 min at 37 ºC. Next, the tubes were incubated for 2 h with a pool of noninactivated AB+ serum, inactivated serum, serum diluted in EGTA-MgCl2, and serum diluted in EDTA. The viability of L. loboi was evaluated and the fungal suspension was cytocentrifuged. The slides were submitted to immunofluorescence staining using human anti-C3 antibody. The results revealed that 98% of the fungi activated the CS by the alternative pathway and no significant difference in L. loboi viability was observed after CS activation. In parallel, frozen histological sections from 11 patients were analyzed regarding the presence of C3 and IgG by immunofluorescence staining. C3 and IgG deposits were observed in the fungal wall of 100% and 91% of the lesions evaluated, respectively. The results suggest that the CS and immunoglobulins may contribute to the defense mechanisms of the host against L. loboi.

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The goal of this project, one of the proposals of the EPS@ISEP Spring 2014, was to develop an Aquaponics System. Over recent years Aquaponics systems have received increased attention since they contribute to reduce the strain on resources within 1st and 3rd world countries. Aquaponics is the combination of Hydroponics and Aquaculture, mimicking a natural environment in order to successfully apply and enhance the understanding of natural cycles within an indoor process. Using this knowledge of natural cycles, it was possible to create a system with capabilities similar to that of a natural environment with the support of electronics, enhancing the overall efficiency of the system. The multinational team involved in the development of this system was composed of five students from five countries and fields of study. This paper describes their solution, including the overall design, the technology involved and the benefits it can bring to the current market. The team was able to design and render the Computer Aided Design (CAD) drawings of the prototype, assemble all components, successfully test the electronics and comply with the budget. Furthermore, the designed solution was supported by a product sustainability study and included a specific marketing plan. Last but not least, the students enrolled in this project obtained new multidisciplinary knowledge and increased their team work and cross-cultural communication skills.

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