1,720,973 research outputs found
NN5: A Neural Network based approach for the downscaling of precipitation fields. Model description and preliminary results
No full textA collection of one year daily forecasts with the MM5 mesoscale model is used to investigate the possibility to downscale hourly precipitation fields from a
horizontal grid spacing of 27 km to one at 3 km. The downscaling is performed
using a multi-layer Neural Network built with information of terrain, land use
and predicted precipitation at the four adjacent grid points of the MM5 coarse
grid. Results obtained for a domain of complex topography show that the
proposed technique produces realistic downscaled precipitation fields.
Emphasis is given to the possible application of the methodology to the
coupling of hydrological and meteorological models or for downscaling coarse
scale climate model precipitation fields to hydrological catchment scales
Cetemps Hydrological Model (CHyM), a distributed grid-based model assimilating different rainfall data sources
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Changing hydrological conditions in the Po basin under global warming
No full textThe Po River is a crucial resource for the Italian economy, since 40% of the gross domestic product comes fromthis
area. It is thus crucial to quantify the impact of climate change on this water resource in order to plan for future
water use. In this paper a mini ensemble of 8 hydrological simulations is completed from1960 to 2050 under the
A1B emission scenario, by using the output of two regional climate models as input (REMO and RegCM) at two
different resolutions (25 km–10 km and 25 km–3 km). The river discharge at the outlet point of the basin shows
a change in the spring peak of the annual cycle, with a one month shift fromMay to April. This shift is entirely due
to the change in snowmelt timing which drives most of the discharge during this period. Two other important
changes are an increase of discharge in the wintertime and a decrease in the fall from September to November.
The uncertainty associated with the winter change is larger compared to that in the fall. The spring shift and the
fall decrease of discharge imply an extension of the hydrological dry season and thus an increase in water stress
over the basin. The spatial distributions of the discharge changes are in agreement with what is observed at the
outlet point and the uncertainty associated with these changes is proportional to the amplitude of the signal.
The analysis of the changes in the anomaly distribution of discharge shows that both the increases and decreases
in seasonal discharge are tied to the changes in the tails of the distribution, i.e. to the increase or decrease of
extreme events
Mapping of Alternaria and Pleospora concentrations in Central Italy using meteorological forecast and neural network estimator
No full textAirborne particles (pollens and fungal spores) are recognized as important causes of allergies and many other pathologies whose main symptoms are usually associated with respiratory problems. In addition these particles seem to be responsible for clinical symptoms of oculorhinitis and bronchial asthma.
Many authors showed how pollen and spore concentrations are critically linked to meteorological conditions, while other studies investigated the possibility to estimate these concentrations through meteorological parameters. So, many different approaches have been proposed, and one of the most sophisticated is based on the use of a complex Artificial Neural Network (ANN) architecture.
Once the neural device is calibrated using simultaneous time series of observed meteorological parameters and airborne biological particles, it is straightforward to use the Neural Network to predict spore concentrations using operational Limited Area Meteorological Model. In a previous work it has been shown that the MM5 meteorological Model developed by National Center for Atmospheric Research and Pennsylvania State University can be coupled with the above cited neural predictor to provide a good prediction of Alternaria and Pleospora spore in the location of L’Aquila (Central Italy). Following the same approach, this work aims to provide the mapping of spore concentration over a wide area covered by high resolution meteorological prediction in Central Italy. The complex patterns of fungal spore concentrations in selected areas will be described and the high temporal variability of such fields will be discussed as well. The possibility to infer useful informations from the predicted pattern of spore concentrations is discussed, as an example it appear that for people suffering from allergy to fungal spores is more comfortable to spend summertime close to the east coast of Italian Peninsula respect to the west coast. A further step of this work may easily lead to an operational use of the model for supporting the clinical management of allergies and for establishing a preventive strategy in agriculture to avoid unsafe and useless pollution of atmosphere, crops and fields
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