1,720,994 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Monitoring of Alpine Snow Conditions Using C-Band SAR
Get PDFThe cryosphere is an essential part of the Earth's climate system, even more in the light of climate change actively impacting the extent of polar ice caps, glaciers and snow. Regions in interaction with these parts of the cryosphere must adapt to challenging conditions, as slight changes in temperature can have irreversible consequences. Informations about the state of a snow pack and ongoing processes within can be a valuable aid, e.g. for avalanche risk management, hydrological run-off models and tourism development. This thesis focuses on revealing connections between various snow parameters, e.g. grain size, snow height or snow wetness, and high-resolution C-band SAR backscatter from ESA's Sentinel missions. Water has a very significant effect in the C-band for different states of aggregation (e.g., solid, liquid) offering a profound physical basis for investigating these relationships in alpine areas with a vast variety of snow conditions. For this case study, an alpine region covering parts of North and South Tyrol, was chosen. Data was acquired for a timespan of over two years, from summer 2015 to autumn 2017. Well-known states of C-band backscatter like sigma naught, which can be related to backscatter from a unit area on ground, hinder a comparison with in-situ snow data due to the inuence of different observation geometries. To overcome this, alternative representations of backscatter, like normalised backscatter, either being normalised by incidence angle or by performing a radiometric (terrain attening) normalisation, are presented in this work. In the former case, linear regression and a novel approach, the piecewise linear percentile slope method, which takes the backscatter distribution of each orbit into account, were used. C-band backscatter was not only analysed as a single band, but also by including cross-polarisation ratios and change detection benefiting from a new method for an automatic, pixel-based reference image selection. Overall, normalised backscatter by means of linear regression and VH polarisation appeared as the best setup, when correlating these data with in-situ snow measurements. Results were enhanced by spatial and temporal Filtering of backscatter data leading to a partial increase in correlation by nearly 0.2. The most meaningful and consistent correlation of -0.64 was found with respect to maximum snow wetness, followed by air temperature (-0.59). Snow height was characterised by the highest correlation (0.67), but its significance is questionable. Concerning snow wetness, change detection performed best, when taking pixels at coldest conditions as reference values into account. Derived maps indicating wet and dry snow could offer useful information for run-off models and for determining fragile snow packs
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Yeoda - providing low-level and easy-to-use access to manifold earth observation datasets
No full textIn recent years, several Python packages (e.g. xarray, rasterio) have evolved around more basic software libraries such as netCDF4 or GDAL for accessing geospatial data. These packages allow to work with all kind of data formats (e.g. GeoTIFF, NetCDF, ZARR) providing the data in array format (NumPy, xarray) and constitute a fundamental part of any scientific analysis or operational task. However, they do not offer full flexibility when working with Earth Observation (EO) datasets. The multidimensional complexity of EO data (i.e. space, time, bands) is often resolved by distributing dimensions across many files and thus not always easy to access. An important step forward to streamline EO data access has been the Open Data Cube (ODC) toolbox, which utilizes predefined dataset configurations and file-based indices stored in a database. With this setup, ODC enables an easy and uniform access to multidimensional geospatial datasets. Still, users are often confronted with a great variety of data formats, and files being distributed over different systems. This can pose a hurdle when working with ODC, especially if one wants to process a new stack of geospatial data, where the extra overhead of a database can stall swift progress.
In order to close this gap, the yeoda (''your earth observation data access'') Python software package aims to resolve this shortcoming by offering a similar interface as ODC, but allowing to interact with geospatial data on a lower level. It relies on two other Python software packages developed by TU Wien: geospade (definition of geospatial properties of a dataset, e.g. geometries), and veranda (read/write access to a variety of raster and vector data formats, e.g. GeoTIFF). This modular setup ensures a clear separation of concerns, specifically between geospatial operations and I/O tasks, yielding a homogenized interface independent from the actual data format. For example, geospatial operations based on tiled EO raster datasets can be easily performed across tile or file boundaries. Data access is then realised in veranda, which combines geometric properties with I/O objects listed in a table. On top of geospade and veranda, yeoda acts as a communication layer between files stored on the file system and data objects by adding additional dimensions to the data table, such as common metadata or file name entries. Thus, one can filter multiple files by their attributes (e.g. time, bands, variable names, satellite platform) before accessing the data.
Hence, yeoda guarantees the necessary freedom to apply arbitrary algorithms on manifold data formats, while simultaneously supporting scalability by means of parallelised I/O operations. Despite ODC's tremendous value for accessing EO datasets through large scale operational services, yeoda introduces a new level of data interaction making it an indispensable tool for the EO user community. When taking a look on recent advancements in interoperable cloud-based processing via the openEO API, yeoda could be utilized as a slim back-end library to lower the hurdle of sharing new EO datasets and to foster scientific exchange
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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