105 research outputs found
Helena de Troya en el séptimo arte
Este estudo analisa as representações da figura de Helena de Tróia no cinema, desde o início do século XX até ao século XXI. Uma das conclusões a que chega é que a figura de Helena tem sido reinterpretada de acordo com as conjunturas político-culturais em cujos âmbitos se inserem as representações cinematográficas.info:eu-repo/semantics/publishedVersio
Data-driven Flood Emulation: Speeding up Urban Flood Predictions by Deep Convolutional Neural Networks
Computational complexity has been the bottleneck of applying physically-based
simulations on large urban areas with high spatial resolution for efficient and
systematic flooding analyses and risk assessments. To address this issue of
long computational time, this paper proposes that the prediction of maximum
water depth rasters can be considered as an image-to-image translation problem
where the results are generated from input elevation rasters using the
information learned from data rather than by conducting simulations, which can
significantly accelerate the prediction process. The proposed approach was
implemented by a deep convolutional neural network trained on flood simulation
data of 18 designed hyetographs on three selected catchments. Multiple tests
with both designed and real rainfall events were performed and the results show
that the flood predictions by neural network uses only 0.5 % of time comparing
with physically-based approaches, with promising accuracy and ability of
generalizations. The proposed neural network can also potentially be applied to
different but relevant problems including flood predictions for urban layout
planning
Publication Performance and Number of Authors – Evidence for World Top Economists
In social sciences the measurement of performance is usually done giving the full credit of each paper to all its authors. Aiming to analyze the impact of the number of authors on the performance results, we propose an adjustment to the h-index that is flexible enough to allow the consideration of distinct co-authorship weighting schemes. We then evaluate the publication performance of the members of the departments of economics of the top 10 world universities (472 authors; 15,243 papers). Our results show that the number of authors per paper is rapidly increasing and that this dimension measurably affects the final ranking of authors even in a scientific area in which the average number of authors is lower than in physical and life sciences
Sodom and Gomorrah in Pompeii
O presente estudo analisa o contexto de uma inscrição encontrada em Pompeios e na qual se lêem os nomes das duas cidades bíblicas de Sodoma e Gomorra. Partindo da hipótese de o grafito ter sido escrito antes ou no momento da erupção do Vesúvio, considera-se a possibilidade de o seu autor, eventualmente um judeu, ter tido a intenção de relacionar o terramoto de 62 ou a catástrofe de 79 d. C. com a ira divina que na tradição bíblica teria destruído Sodoma e Gomorra.O presente estudo analisa o contexto de uma inscrição encontrada em Pompeios e na qual se lêem os nomes das duas cidades bíblicas de Sodoma e Gomorra. Partindo da hipótese de o grafito ter sido escrito antes ou no momento da erupção do Vesúvio, considera-se a possibilidade de o seu autor, eventualmente um judeu, ter tido a intenção de relacionar o terramoto de 62 ou a catástrofe de 79 d. C. com a ira divina que na tradição bíblica teria destruído Sodoma e Gomorra.This paper studies the context of an inscription found in Pompeii, which refers to the Biblical cities of Sodom and Gomorrah. If the graffito was written before or during the volcanic eruption, it is possible that its Author, probably a Jew, had connected the earthquake of 62 or the catastrophe of 79 A.D. with the Divine wrath that, according the Biblical tradition, had destroyed Sodom and Gomorrah
Publication Performance and Number of Authors – Evidence for World Top Economists
In social sciences the measurement of performance is usually done giving the full credit of each paper to all its authors. Aiming to analyze the impact of the number of authors on the performance results, we propose an adjustment to the h-index that is flexible enough to allow the consideration of distinct co-authorship weighting schemes. We then evaluate the publication performance of the members of the departments of economics of the top 10 world universities (472 authors; 15,243 papers). Our results show that the number of authors per paper is rapidly increasing and that this dimension measurably affects the final ranking of authors even in a scientific area in which the average number of authors is lower than in physical and life sciences
The problem of credit in research evaluation – the case of Economics
The measurement of scientific performance is usually done giving the full credit of each paper to all its authors. Aiming to analyze the impact of the number of authors on the performance, we propose an adjustment to the h-index that is flexible enough to allow the consideration of distinct co-authorship weighting schemes. We then evaluate the publication performance of the members of the departments of economics of the top 10 world universities. Our results show that the number of authors per paper is rapidly increasing and that this dimension measurably affects the final ranking of authors even in a subject area where the average number of authors is lower than in physical and life sciences
Stochastic urban pluvial flood hazard maps based upon a spatial-temporal rainfall generator
It is a common practice to assign the return period of a given storm event to the urban pluvial flood event that such storm generates. However, this approach may be inappropriate as rainfall events with the same return period can produce different urban pluvial flooding events, i.e., with different associated flood extent, water levels and return periods. This depends on the characteristics of the rainfall events, such as spatial variability, and on other characteristics of the sewer system and the catchment. To address this, the paper presents an innovative contribution to produce stochastic urban pluvial flood hazard maps. A stochastic rainfall generator for urban-scale applications was employed to generate an ensemble of spatially—and temporally—variable design storms with similar return period. These were used as input to the urban drainage model of a pilot urban catchment (~9 km2) located in London, UK. Stochastic flood hazard maps were generated through a frequency analysis of the flooding generated by the various storm events. The stochastic flood hazard maps obtained show that rainfall spatial-temporal variability is an important factor in the estimation of flood likelihood in urban areas. Moreover, as compared to the flood hazard maps obtained by using a single spatially-uniform storm event, the stochastic maps generated in this study provide a more comprehensive assessment of flood hazard which enables better informed flood risk management decisions
Urban Pluvial Flood Forecasting
Two main approaches to enhance urban pluvial flood prediction were developed
and tested in this research: (1) short-term rainfall forecast based on rain gauge
networks, and (2) customisation of urban drainage models to improve hydraulic
simulation speed. Rain gauges and level gauges were installed in the Coimbra
(Portugal) and Redbridge (UK) catchment areas. The collected data was used
to test and validate the approaches developed.
When radar data is not available urban pluvial flooding forecasting can be based
on networks of rain gauges. Improvements were made in the Support Vector
Machine (SVM) technique to extrapolate rainfall time series. These improvements
are: enhancing SVM prediction using Singular Spectrum Analysis (SSA)
for pre-processing data; combining SSA and SVM with a statistical analysis that
gives stochastic results. A method that integrates the SVM and Cascade-based
downscaling techniques was also developed to carry out high-resolution (5-min)
precipitation forecasting with longer lead time. Tests carried out with historical
data showed that the new stochastic approach was useful for estimating the
level of confidence of the rainfall forecast. The integration of the cascade method
demonstrates the possibility of generating high-resolution rainfall forecasts with
longer lead time. Tests carried out with the collected data showed that water
level in sewers can be predicted: 30 minutes in advance (in Coimbra), and 45
minutes in advance (in Redbridge).
A method for simplifying 1D1D networks is presented that increases computational
speed while maintaining good accuracy. A new hybrid model concept was
developed which combines 1D1D and 1D2D approaches in the same model to
achieve a balance between runtime and accuracy. While the 1D2D model runs
in about 45 minutes in Redbridge, the 1D1D and the hybrid models both run
in less than 5 minutes, making this new model suitable for flood forecasting
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