581 research outputs found
On improving the efficiency of ADER methods
No full textThe (modern) arbitrary derivative (ADER) approach is a popular technique for
the numerical solution of differential problems based on iteratively solving an
implicit discretization of their weak formulation. In this work, focusing on an
ODE context, we investigate several strategies to improve this approach. Our
initial emphasis is on the order of accuracy of the method in connection with
the polynomial discretization of the weak formulation. We demonstrate that
precise choices lead to higher-order convergences in comparison to the existing
literature. Then, we put ADER methods into a Deferred Correction (DeC)
formalism. This allows to determine the optimal number of iterations, which is
equal to the formal order of accuracy of the method, and to introduce efficient
-adaptive modifications. These are defined by matching the order of accuracy
achieved and the degree of the polynomial reconstruction at each iteration. We
provide analytical and numerical results, including the stability analysis of
the new modified methods, the investigation of the computational efficiency, an
application to adaptivity and an application to hyperbolic PDEs with a Spectral
Difference (SD) space discretization
DeC and ADER: Similarities, Differences and a Unified Framework
No full textIn this paper, we demonstrate that the explicit ADER approach as it is used inter alia in
Zanotti et al. (Comput Fluids 118:204–224, 2015) can be seen as a special interpretation of the
deferred correction (DeC) method as introduced in Dutt et al. (BIT Numer Math 40(2):241–
266, 2000). By using this fact, we are able to embed ADER in a theoretical background of
time integration schemes and prove the relation between the accuracy order and the number
of iterations which are needed to reach the desired order. Next, we extend our investigation to
stiff ODEs, treating these source terms implicitly. Some differences in the interpretation and
implementation can be found. Using DeC yields typically a much simpler implementation,
while ADER benefits from a higher accuracy, at least for our numerical simulations. Then,
we also focus on the PDE case and present common space-time discretizations using DeC
and ADER in closed forms. Finally, in the numerical section we investigate A-stability for
the ADER approach—this is done for the first time up to our knowledge—for different order
using several basis functions and compare them with the DeC ansatz. Then, we compare the
performance of ADER and DeC for stiff and non-stiff ODEs and verify our analysis focusing
on two basic hyperbolic problems
Veiga Ferreira e a Paleontologia em Portugal
No full textThis communication deals with the less known research activities on Palconlology by Octávio da Veiga Ferreira, since just
after he became a member of the staff of the Serviços Geológicos de Portugal. These activities lasted for about 25 years (1951-1975, eventually up to 1987). Besides much field and laboralory work, Veiga Ferreira produced (alone or in collaboration} 38
papers. These concern vertebrates, echinoids, pectens and other molluscs, and malacostraca, as well as some papers of a more general or divulgation character. Studied fossils range from Jurassic to Quaternary, and from continental Portugal to Santa Maria Island (Azores), the Madeira Archipel and Angola.
Veiga Ferreira is author of much valid work. He generously helped others as well.
A bibliography for his paleontological papers is provided
Intermidialidade e remediação em Onde andará Dulce Veiga?, de Caio Fernando Abreu, e Short Movies, de Gonçalo M. Tavares
No full textInternational audienceIn this paper, I analyze contemporary narratives in which cinema is present as an “intermedial reference”. In this regard, I draw on intermediality theories to study the books Onde andará Dulce Veiga? (1990), written by the Brazilian author Caio Fernando Abreu, and Short Movies, by the Portuguese writer Gonçalo M. Tavares. My aim is to investigate some types of exchange between literature and cinema, and to highlight the possible advantages this process brings for both medias.L’objectif de ce travail est d’analyser la présence du cinéma, sous la forme de « référence intermédiale », dans la littérature lusophone contemporaine. Dans ce but, nous étudions les récits Onde andará Dulce Veiga? (1990), de l’écrivain brésilien Caio Fernando Abreu, et Short Movies, du portugais Gonçalo M. Tavares. Nous analysons les échanges entre littérature et cinéma, et nous soulignons les avantages que cela peut apporter aux deux médias.Resumo Neste trabalho, pretende-se analisar narrativas contemporâneas em que o cinema esteja presente, sob a forma de "referência intermidiática". Nesse sentido, são empregadas teorias provenientes dos estudos da intermidialidade para analisar as obras Onde andará Dulce Veiga? (1990), do brasileiro Caio Fernando Abreu, e Short Movies, do português Gonçalo M. Tavares. Espera-se investigar determinadas trocas entre literatura e cinema, apontando possíveis ganhos para ambas as mídias nesse processo
Máquinas, muros e o galo impertinente: o realismo mágico literário de José J. Veiga na reflexão acerca da ditadura militar no Brasil e proposta didática para ensino de história
No full textThis work is dedicated to researching the relationship between the works of magical realism by Goiás author José J. Veiga and the context of the military dictatorship in which they were published, pointing out ways of using this literary language in teaching the history of the period. To this end, research in the field of history that focuses on the literature of the dictatorship period is reviewed and the short stories O Galo Impertinente (1967) and A Máquina Extraviada (1967) and the novel Sombras De Reis Barbudos (1972) by José J. Veiga are analyzed based on Roger Chartier's notion of representation (1991;2010). The aim of the work is to produce a didactic product in ebook format for teachers of the 9th grade of elementary school, with guidelines for using literature in the classroom to teach the content of the military dictatorship. From the perspective of history education, the aim was to contribute to historical awareness of the dictatorial period.Esse trabalho se dedica a pesquisar a relação das obras do gênero realismo mágico do autor goiano José J. Veiga com o contexto de ditadura militar em que foram publicadas, apontando maneiras de utilizar essa linguagem literária no ensino de história do período. Para tal, são revisadas as pesquisas da área de história que enfocam a literatura do período ditatorial e analisados os contos O Galo Impertinente (1967) e A Máquina Extraviada (1967) e o romance Sombras de Reis Barbudos (1972) de José J. Veiga a partir da noção de representação de Roger Chartier (1991;2010). O trabalho tem como objetivo a elaboração de um produto didático em formato de ebook voltado a professores do 9º ano do Ensino Fundamental, com orientações para uso da literatura em sala no ensino do conteúdo de ditadura militar. A partir da perspectiva da educação histórica objetivasse contribuir na consciência histórica acerca do período ditatorial
Correction to: Yoghurt consumption is associated with changes in the composition of the human gut microbiome and metabolome
No full textFollowing the publication of the original paper [1], there’s an error on the first name of one of the authors. Mureil Derrien should be Muriel Derrien. Correct name is shown in the author group section above. The original article has been corrected
Análisis cinemático de la salida con empuje en nadadores competitivos de nivel nacional
No full textEn natación, el estudio de los parámetros cinemáticos del movimiento a través de la biomecánica ha revelado información muy detallada de las diferentes partes de la competición (salida, nado y viraje). Especialmente el estudio de las fases subacuáticas tras la salida y el viraje han mostrado su importante contribución al rendimiento del nadador y la han convertido en un parámetro evaluable, en sus diferentes fases que son: el deslizamiento, el movimiento ondulatorio subacuático, la transición del buceo al nado y el nado en superficie. Sin embargo, no se han analizado dichas fases cuando el empuje del nadador se realiza desde dentro del agua, que es lo que ocurre en la práctica diaria del entrenamiento. En la presente tesis, se han analizado los parámetros cinemáticos de 222 salidas con empuje desde dentro del agua en nadadores competitivos de nivel nacional. La muestra (N=74) ha estado compuesta por nadadores que pertenecían a 8 clubes de la ciudad de Madrid de categoría nacional. A cada nadadorse le registró el tiempo, la distancia y la velocidad en las diferentes fases de la salida con empuje, teniendo en cuenta la influencia del género y el estilo de nado. La investigación se llevó a cabo mediante un análisis de vídeo a una frecuencia de muestro de 25 Hz y los parámetros cinemáticos se calcularon utilizando algoritmos de la técnica experimental DLT en dos dimensiones. La velocidad, distancia y tiempo de cada una de las fases de la salida con empuje fueron analizados mediante una ANOVA de medidas repetidas en función del género y el estilo de los sujetos. Los resultados sobre la caracterización de las fases mostraron que la velocidad disminuyó progresivamente, desde la fase del deslizamiento subacuático hasta la fase del nado en superficie (2,22±0,02 m/s; 1,61±0,01 m/s; 1,48±0,03 m/s y 1,46±0,02 m/s). Por otro lado, el tiempo y la distancia fueron mayores en la fase del movimiento ondulatorio subacuático (3,14±0,07 s y 4,92±0,10 m) en comparación con el resto de fases. La fase del movimiento ondulatorio subacuático fue la fase más importante y la que más se correlacionó con la velocidad media de la salida, mientras que la fase de transición al nado fue la que menos influencia tuvo. En cuanto a la influencia del género, tanto hombres como mujeres, emplearon el mismo tiempo en el desarrollo de la fase del deslizamiento (0,59±0,03 s) y en la fase de transición al nado (0,57±0,03 y 0,51±0,03 s). Los hombres recorrieron mayores distancias (1,37±0,06 vs 1,20±0,05 m; 5,03±0,14 vs 4,82±0,13 m; 0,84±0,04 vs 0,66±0,04 m; 3,28±0,06 vs 3,18±0,05 m; 7,26±0,16 vs 6,67±0,14 m; 10,54±0,15 vs 9,85±0,14 m) y con más velocidad (2,36±0,03 vs 2,08±0,03 m/s; 1,73±0,02 vs 1,50±0,02 m/s; 1,59±0,03 vs 1,38±0,03 m/s; 1,54±0,03 vs 1,38±0,03 m/s; 1,80±0,02 vs 1,57±0,02 m/s; 1,71±0,02 vs 1,49±0,02 m/s) que las mujeres en todas las fases. En la influencia del estilo, no se observaron diferencias entre crol y mariposa en ninguno de los parámetros analizados, mientras que las salidas realizadas a estilo de espalda mostraron menor velocidad en todas las fases analizadas (2,12±0,04; 1,52±0,02; 1,37±0,04; 1,24±0,04; 1,55±0,02; 1,46±0,02m/s) y mayor distancia durante la fase del movimiento ondulatorio (6,47±0,17 m frente 3,88±0,16 y 4,42±0,16 m). El batido realizado durante el movimiento ondulatorio subacuático se caracterizó por una mayor frecuencia (0,15 Hz), longitud (0,06 m) y velocidad (0,24 m/s) en los hombres que en las mujeres. Por otro lado, se observaron diferencias entre los estilos de manera que en crol (0,80±0,01 m y 1,68±0,02 m/s) y mariposa (0,8±0,01 m y 1,66±0,02 m/s) la longitud y velocidad del batido subacuático fue mayor que en espalda, aunque su frecuencia (2,14±0,04 Hz en espalda por 2,11±0,04 y 2,10±0,04) fue menor. ----------ABSTRACT---------- In swimming, the study of the kinematic parameters of movement through biomechanics has indicated very detailed information of the different parts of the competition (start, swim and turn). Especially, the study of the underwater phases after start and turn have shown their important contribution to the performance of the swimmer and have become an evaluable parameter in their different phases, which are: gliding, underwater wave movement, the transition from dive to swim and swim on surface. However, these phases have not been analyzed when the swimmer's push-off start is made from within the water, which is what happens in the daily practice of training. In the present thesis, the kinematic parameters of 222 starts with a wall push-off from within the water in competitive swimmers of national level have been analyzed. The sample (N = 74) was composed by swimmers who belonged to 8 clubs of the city of Madrid in the national category. Each swimmer’s time, distance and velocity in the different phases of the push-off start was recorded, taking into account the influence of gender and the swim style. The research was carried out by video analysis at a sampling frequency of 25 Hz and kinematic parameters were calculated using algorithms from the experimental DLT technique in two dimensions. The velocity, distance and time of each of the phases of push-off start were analyzed by means of a repeated measures ANOVA according to the style and the gender of the subjects. The results on the characterization of the phases showed that the velocity decreased progressively, from the underwater gliding phase to the surface swimming phase (2.22 ± 0.02 m/s, 1.61 ± 0.01 m/s, 1.48 ± 0.03 m/s and 1.46 ± 0.02 m/s). On the other hand, time and distance were higher in the underwater wave phase (3.14 ± 0.07 s and 4.92 ± 0.10 m) compared to the rest of the phases. The phase of underwater wave movement was the most important phase and the one that most correlated with the mean velocity of the start, while the phase of transition to swim was the one that had the least influence. As for the influence of gender, both men and women, used the same time in the development of the glide phase (0.59 ± 0.03 s) and in the transition to swim phase (0.57 ± 0.03 and 0.51 ± 0.03 s). Men travelled greater distances (1.37 ± 0.06 vs 1.20 ± 0.05 m, 5.03 ± 0.14 vs 4.82 ± 0.13 m, 0.84 ± 0.04 vs 0, 66 ± 0.04 m, 3.28 ± 0.06 vs 3.18 ± 0.05 m, 7.26 ± 0.16 vs 6.67 ± 0.14 m, 10.54 ± 0.15 vs 9,85 ± 0.14 m) and with a higher velocity (2.36 ± 0.03 vs 2.08 ± 0.03 m/s, 1.73 ± 0.02 vs 1.50 ± 0.02 m/s, 1.59 ± 0.03 vs 1.38 ± 0.03 m/s, 1.54 ± 0.03 vs 1.38 ± 0.03 m/s, 1.80 ± 0.02 vs 1.57 ± 0.02 m/s, 1.71 ± 0.02 vs. 1.49 ± 0.02 m/s) than women in all phases. In the influence of style, no differences were observed between freestyle and butterfly in any of the analyzed parameters, while the backstroke style start showed lower velocity in all phases analyzed (2.12 ± 0.04, 1.52 ± 0.02, 1.37 ± 0.04, 1.24 ± 0.04, 1.55 ± 0.02, 1.46 ± 0.02m/s) and greater distance during the phase of wave movement (6,47 ± 0.17 m versus 3.88 ± 0.16 and 4.42 ± 0.16 m). The underwater dolphin kick performed during underwater wave movement was characterized by a higher frequency (0.15 Hz), length (0.06 m) and velocity (0.24 m/s) in men than in women. On the other hand, differences between the styles were observed in freestyle (0.80 ± 0.01 m and 1.68 ± 0.02 m/s) and butterfly (0.8 ± 0.01 m and 1.66 ± 0.02 m/s) the length and velocity of the underwater wave dolphin kick was higher than in backstroke, although its frequency (2.14 ± 0.04 Hz in backstroke by 2.11 ± 0.04 and 2.10 ± 0.04) was lower
Sobre el significado del “pretérito perfecto” español y el estudio de su variación geolingüística
No full textConcerning the article on Cuban Spanish (Montero Cádiz in this issue), the author reflects on the geolinguistic variation of Spanish in terms of “he cantado / canté” functional distinction, on the Cuban corpus studied, on the effects of linguistic prestige of "peninsular Spanish" and on specific aspects of the tense-aspect interrelationship in grammatical interpretation of “pretérito perfecto”.A propósito del artículo de M. M. Montero Cádiz sobre el español cubano, el autor reflexiona sobre la variación geolingüística del español en cuanto a la distinción funcional he cantado / canté, sobre el corpus cubano estudiado, sobre los efectos del prestigio lingüístico del “español peninsular” y sobre aspectos concretos de la interrelación tiempo-aspecto en la interpretación gramatical del “pretérito perfecto”
El miembro avilé de la formación agrio (Cretácico temprano)
No full textEn este capítulo se presentan las principales características de los depósitos continentales del Miembro Avilé de la Formación Agrio.
Esta unidad de edad hauteriviana representa un evento regresivo de baja frecuencia que superpone a estos depósitos continentales de forma abrupta sobre facies marinas profundas del Miembro Pilmatué de la Formación Agrio. Este evento regresivo se traduce en el desarrollo de un potente registro vinculado con sistemas de acumulación continental localizado hacia la porción central de la
cuenca. El límite superior de la unidad está marcado por un evento transgresivo de orden mayor a partir del cual se restablecen las condiciones marinas en la cuenca con la acumulación del Miembro Agua de la Mula. A partir del análisis de facies y arquitectural detallado se han identificado sucesiones asociadas con sistemas fluviales (entrelazados y de carga mixta), eólicos y lacustres (abiertos
e hipersalinos). La distribución de estos sistemas de acumulación en el espacio y a lo largo de la evolución estratigráfica del Miembro Avilé muestra un complejo arreglo que se vincula con cambios laterales y temporales de diversos factores como el clima, la evolución de largo plazo del nivel freático y la disponibilidad de sedimentos.The Avile Member of the Agrio Formation (Early Cretaceous).- The main characteristics of the non-marine deposits of the Avilé Member of the Agrio Formation are presented in this chapter. This Hauterivian unit represents a low-order regressive event that accumulates non-marine deposits directly on top of deep-marine shales of the Pilmatué Member of the Agrio Formation. In
response to this regressive event, a thick record of non-marine depositional systems is accumulated in the central part of the basin.
The upper boundary of this unit is marked by a low-order transgressive event that re-establishes deep-marine accumulation of the Agua de la Mula Member of the Agrio Formation. Facies and architectural analysis allowed the identification of fluvial (braided and mixed-load high sinuosity), aeolian and lacustrine (hypersaline and open) systems. The distribution of these depositional systems
in space and time during the accumulation of the Avilé Member reflects a complex array related to lateral and temporal changes in external forcing factors as climate, long-term water-table evolution and sediment availability.Fil: Veiga, Gonzalo D. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones Geológicas; Argentina.Fil: Spalletti, Luis A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones Geológicas; Argentina.Fil: Schwarz, Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones Geológicas; Argentina.Fil: Vallés, Jorge M. Universidad Nacional del Comahue. Facultad de Ingeniería; Argentina
Urbanização, Saneamento e Marginalização: uma análise da construção da Avenida Hercílio Luz 1918-1922
No full textTCC (graduação) - Universidade Federal de Santa Catarina. Centro de Filosofia e Ciências Humanas, Departamento de História.Este trabalho de conclusão de curso propõe uma análise das reformas urbanas em Florianópolis entre os anos 1918-1922. Primeiramente contextualizando rapidamente o contexto brasileiro da virada do século XIX e XX, marcado por profundas transformações sociais, políticas, econômicas, culturais, e a proliferação de ideais de higienistas e sanitaristas em território nacional. Em seguida, analisamos o contexto florianopolitano neste período, como os discursos e práticas sanitárias/higienistas influenciaram em medidas de controle e segregação da sociedade, principalmente dos estratos sociais mais pobres da cidade; culminando nas obras da Avenida do Saneamento - atual Hercílio Luz -, e consequente marginalização de inúmeras famílias do centro para a periferia da cidade - foco principal deste trabalho-, legitimada pelos discursos higienistas aos quais estavam vinculadas as ideias de “modernidade” e “civilidade”
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