1,052 research outputs found
Integrated local control of active power and voltage support for three-phase three-wire converters
The derivation of a robust control algorithm is presented to provide decoupled active power regulation and local grid voltage support in three-phase three-wire grid-connected converters (GCCs). Unlike conventional control schemes, the proposed strategy is designed to be harmonic sequence asym-metric for the purpose of local voltage unbalance correction. A frequency-domain Norton equivalent model is derived to illustrate the working principle of the strategy. Accordingly, by following a frequency-domain decoupled method, the funda-mental positive-sequence, the harmonic symmetrical sequences and the fundamental negative-sequence components are regu-lated independently. Consistent to the model analysis, simulation results validate reduction of local voltage unbalance and total harmonic distortion. Since no external sensors are required for the implementation of the strategy, it is a local approach, applicable to already-existing GCC systems. Moreover, in view of the higher switching frequencies as attainable by devices from the next SiC generation, the accuracy and dynamic behavior of the control algorithms can be much enhanced, improving therefore the quality of the processed energy
On stochastic sea of the standard map
Consider a generic one-parameter unfolding of a homoclinic tangency of an
area preserving surface diffeomorphism. We show that for many parameters
(residual subset in an open set approaching the critical value) the
corresponding diffeomorphism has a transitive invariant set of full
Hausdorff dimension. The set is a topological limit of hyperbolic sets
and is accumulated by elliptic islands.
As an application we prove that stochastic sea of the standard map has full
Hausdorff dimension for sufficiently large topologically generic parameters.Comment: 36 pages, 5 figure
Adaptação transcultural para o idioma português do método de triagem nutricional Determine your nutritional health (R) para idosos domiciliados / Cross-cultural adaptation to the Portuguese language of the Determine Your Nutritional Health (R) screening method for the elderly in assisted living accommodation
ABSTRACT IN PORTUGESE: O objetivo deste artigo Ă© descrever o processo de adaptação transcultural do mĂ©todo de triagem nutricional, Determine Your Nutritional Health® (DNH), para utilização na população idosa brasileira. O DNH consiste de 10 questões com enunciados afirmativos, Ă s quais sĂŁo atribuĂdas pontuações especĂficas e cuja soma corresponde ao escore final, que classifica os indivĂduos de acordo com a presença ou a ausĂŞncia de risco nutricional. O processo de adaptação transcultural do mĂ©todo DNH envolveu as seguintes etapas: tradução; retrotradução; equivalĂŞncia semântica; avaliação dos especialistas; prĂ©-teste e versĂŁo final do mĂ©todo. Foram realizadas adaptações de palavras e expressões do mĂ©todo DNH, para a realidade brasileira. A versĂŁo final do mĂ©todo foi definida para o Brasil como “Verifique a condição nutricional do idoso”, apresentando as mesmas questões da versĂŁo original do DNH, contudo, em formato mais claro, por meio de perguntas, consideradas acessĂveis e de fácil entendimento, segundo a avaliação de profissionais de saĂşde e de idosos. A versĂŁo brasileira do mĂ©todo de triagem nutricional, “Verifique a condição nutricional do idoso”, encontra-se traduzida e adaptada para uso em idosos brasileiros domiciliados.
ABSTRACT IN ENGLISH: This article aims to describe the process of cross-cultural adaptation of the Determine Your Nutritional Health® (DNH) screening method for the elderly Brazilian population. The DNH consists of 10 questions with affirmative statements, to which specific scores are assigned and when added up correspond to the final score, which classifies individuals according to the presence or absence of nutritional risk. The process of cross-cultural adaptation of the DNH method involved the following stages: translation; back translation; semantic equivalence; evaluation by the experts; pre-test and final version of the method. Adjustments were made in words and expressions of the DNH method for the Brazilian reality. The final version of the method has been defined for Brazil as “Verify the nutritional conditions of the elderly,” presenting the same questions as in the original version of the DNH. It was in a clearer format, through questions, considered accessible and easy to understand, according to the assessment of health professionals and the elderly. The Brazilian version of the nutritional screening method, “Verify nutritional conditions of the elderly,” was translated and adapted, for use in Brazilian elderly in assisted living accommodation
Some remarks on the geometry of the Standard Map
We define and compute hyperbolic coordinates and associated foliations which
provide a new way to describe the geometry of the standard map. We also
identify a uniformly hyperbolic region and a complementary 'critical' region
containing a smooth curve of tangencies between certain canonical 'stable'
foliations.Comment: 25 pages, 11 figure
Dynapenic abdominal obesity increases mortality risk among English and Brazilian older adults: A 10-year follow-up of the ELSA and SABE studies
BACKGROUND/OBJECTIVE: There is little epidemiological evidence demonstrating that dynapenic abdominal obesity has higher mortality risk than dynapenia and abdominal obesity alone. Our main aim was to investigate whether dynapenia combined with abdominal obesity increases mortality risk among English and Brazilian older adults over ten-year follow-up.
DESIGN: Cohort study.
SETTING: United Kingdom and Brazil.
PARTICIPANTS: Data came from 4,683 individuals from the English Longitudinal Study of Ageing (ELSA) and 1,490 from the Brazilian Health, Well-being and Aging study (SABE), hence the final sample of this study was 6,173 older adults.
MEASUREMENTS: The study population was categorized into the following groups: nondynapenic/ non-abdominal obese, abdominal obese, dynapenic, and dynapenic abdominal obese according to their handgrip strength ( 102 cm for men and > 88 cm for women). The outcome was all-cause mortality over a ten-year follow-up. Adjusted hazard ratios by sociodemographic, behavioural and clinical characteristics were estimated using Cox proportional hazards models. Results: The fully adjusted model showed that dynapenic abdominal obesity has a higher mortality risk among the groups. The hazard ratios (HR) were 1.37 for dynapenic abdominal obesity (95% CI = 1.12–1.68), 1.15 for abdominal obesity (95% CI = 0.98–1.35), and 1.23 for dynapenia (95% CI = 1.04–1.45).
CONCLUSIONS: Dynapenia is an important risk factor for mortality but dynapenic abdominal obesity has the highest mortality risk among English and Brazilian older adults
Inflammation and quality of life in later life: findings from the health, well-being and aging study (SABE)
BACKGROUND: Few studies have specifically investigated the inverse relationship between reduced quality of life in different domains and elevated C-reactive protein (CRP) serum levels in older adults. Therefore, this study investigates the cross-sectional association between quality of life and inflammation in older Brazilian adults. METHODS: Data were collected from 1255 participants from the third wave (2010) of the Brazilian Health, Well-being and Aging study (SABE), a community-based cohort study of aging. Inflammation was assessed using CRP serum levels and quality of life (QoL) was measured using the 12-item Short-Form Health Survey (SF-12) questionnaire. The covariates included age, sex, education level, financial sufficiency, number of non-communicable diseases, self-reported doctor diagnosed diseases, Activity of Daily Living (ADL) difficulties, Body Mass Index (BMI), and waist circumference. RESULTS: The fully adjusted models showed that older adults with low scores in the physical domain of the SF12 (OR 1.34, 95%CI 1.02;1.77) and high BMI values (> 30) (OR 2.05, 95%CI 1.50;2.81) were more likely to present high CRP serum levels. CONCLUSION: Our findings suggest a significant association of lower scores in the physical domain of quality of life and the presence of obesity with high CRP serum levels
Gravity, magnetic field, and turbulence: relative importance and impact on fragmentation in the infrared dark cloud G34.43+00.24
We investigate the interplay between magnetic (B) field, gravity, and turbulence in the fragmentation process of cores within the filamentary infrared dark cloud G34.43+00.24. We observe the magnetic field morphology across G34.43, traced with thermal dust polarization at 350 μm with an angular resolution of 10'' (0.18 pc), and compare with the kinematics obtained from N2H+ across the filament. We derive local velocity gradients from N2H+, tracing motion in the plane of sky, and compare with the observed local B field orientations in the plane of sky. The B field orientations are found to be perpendicular to the long axis of the filament toward the MM1 and MM2 ridge, suggesting that the B field can guide material toward the filament. Toward MM3, the B field orientations appear more parallel to the filament and aligned with the elongated core of MM3, indicating a different role of the B field. In addition to a large-scale east–west velocity gradient, we find a close alignment between local B field orientations and local velocity gradients toward the MM1/MM2 ridge. This local correlation in alignment suggests that gas motions are influenced by the B field morphology or vice versa. Additionally, this alignment seems to become even closer with increasing integrated emission in N2H+, possibly indicating that a growing gravitational pull alignes the B field and gas motion more and more. We analyze and quantify B field, gravity, turbulence, and their relative importance toward the MM1, MM2, and MM3 regions with various techniques over two scales, a larger clump area at 2 pc scale and the smaller core area at 0.6 pc scale. While gravitational energy, B field, and turbulent pressure all grow systematically from large to small scale, the ratios among the three constituents clearly develop differently over scale. We propose that this varying relative importance between B field, gravity, and turbulence over scale drives and explains the different fragmentation types seen at subparsec scale (no fragmentation in MM1; aligned fragmentation in MM2; clustered fragmentation in MM3). We discuss uncertainties, subtleties, and the robustness of our conclusion, and we stress that a multiscale joint analysis is required to understand the dynamics in these systems
The Brazilian Longitudinal Study of Aging (ELSI-Brazil): Objectives and Design
Brazil is experiencing among the world’s fastest demographic aging worldwide. This demographic transition is occurring in a context of few resources and great social inequalities. The Brazilian Longitudinal Study of Aging (ELSI-Brazil) is a nationally representative study of 9,412 people aged 50 years or older, residing in 70 municipalities across the 5 Brazilian regions. ELSI-Brazil allows investigations of the aging process, its health, psychosocial and economic determinants, and societal consequences. The baseline examination (2015–2016) included detailed household and individual interviews and physical measurements (blood pressure, anthropometry, grip strength, and timed walk and balance tests). Blood tests and sample storage were performed in a subsample of study participants. Subsequent waves are planned for every 3 years. The study adopts a conceptual framework common to other large-scale longitudinal studies of aging in the world, such as the Health and Retirement Study, allowing cross-national comparisons. The goal of ELSI-Brazil is not only to build an understanding of aging in a large, Western, middle-income country in a rapid demographic transition but also to provide scientific data to support and study policy changes that may affect older adults. We describe the methodology of the study and some descriptive results of the baseline survey
Socioeconomic inequalities in activities of daily living limitations and in the provision of informal and formal care for noninstitutionalized older Brazilians: National Health Survey, 2013
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