1,720,970 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
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
Soil Physics at Remote Sensing Footprint Scale: Emergent Properties and Applications
No full textSoil moisture (SM) accounts for a small fraction of the total global freshwater but exerts a disproportionately large influence on the global water budget. Decades-old efforts in characterizing SM controls at large spatial scales have made little difference in the process representation of soils in the existing land-surface/ Earth-System models. Currently, soil hydrological modeling remains starkly divided into two distinct paradigms: i) Point-to-field scale Vadose Zone Models, which treat soil as a 3-D porous media and the unsaturated flow is modeled with a fully parameterized, 4-D space-time model based on Richard���s equation, and, ii) Catchment Hydrology Models, where the soil is treated as a thin layer with finite, yet dynamic storage capacity. Fully distributed hyper-resolution hydrological models converge these paradigms, where the distributed soil parameters for the models are estimated by i) model inversion/ calibration or ii) through pedo-transfer functions, assuming the validity of Richard���s equation for modeling SM flow beyond fine scales. Despite critical limitations of application of Richard���s equation beyond a very limited spatial extent (typically ~1m), a universally accepted unified mathematical representation of landscape-scale flow in the vadose zone remains critically missing.
This study proposes a new paradigm of vadose zone process modeling to account for the complex and simultaneous interactions between hydro-bio-geo-chemical processes at the landscape scale as observed through remote sensing. We propose incorporating the emergent patterns of ecosystem-scale terrestrial water and energy linkages to develop a new understanding of vadose zone processes. We hypothesize that the effective manifestation of the spatiotemporal variability and controls of SM at landscape scales is engrained in scale-specific ���emergent��� properties, observable using remote-sensing datasets. Such emergent properties can be used to study, model, and predict soil hydrology, while accounting for the coupled processes in the hydro-bio-atmosphere which govern the effective SM dynamics at landscape scales. The objective of this research is to i) identify novel ���emergent��� properties of SM dynamics and controls at the landscape scale using remote sensing and, ii) demonstrate the application of the emergent SM properties in understanding SM dynamics and physical controls, hydrological modeling and monitoring hydrological extremes from continental- to- global scale
Near Real-time Seasonal Drought Forecasting and Retrospective Drought Analysis using Simulated Multi- layer Soil Moisture from Hydrological Models at Sub- Watershed Scales
No full textThis study proposes a stratified approach of drought severity assessment using multi-layer simulated soil moisture. SWAT (Soil and Water Assessment Tool) models are calibrated for 50 watersheds in the South-Atlantic Gulf region of the Southeastern US and a high-resolution daily soil moisture dataset is obtained at Hydrologic Unit Code (HUC-12) resolution for a period of January 1982 through December 2013. A near real-time hydrologic simulation framework by coupling the calibrated SWAT models with the National Centers for Environmental Prediction (NCEP) coupled forecast system model version 2 (CFSv2) weather data is developed to forecast various water balance components including soil moisture (SM), actual evapotranspiration (ET), potential evapotranspiration ET (PET), and runoff (SURQ) for near-real time drought severity assessment, and drought forecasting for a lead of 9-months. A combination of the surface and total rooting depth soil moisture percentiles proves to be an effective increment over conventional drought assessment approaches in capturing both, transient and long-term drought impacts. The proposed real-time drought monitoring approach shows high accuracy in capturing drought onset and propagation and shows a high degree of similarity with the U.S. Drought Monitor (USDM), the long-term (PDSI, PHDI, SPI-9 and SPI-12), and the short-term (Palmer Z index, SPI-1 and SPI-6) drought indices.Master of ScienceDrought, a recurring and worldwide phenomenon, with spatial and temporal characteristics varying significantly from across globe, lead to long-term and cumulative environmental changes. Often referred to as creeping phenomena, droughts are difficult to predict and constant monitoring is required to capture the signs of the onset of drought. Spatial variability in drought severity requires an understanding of the hydrology of the region and a knowledge of the relationship between drought inducing climatic extremes and other regional or local characteristics which help build, sustain and propagate droughts. In the absence of long-term observed hydrologic variables like soil moisture, evapotranspiration, simulated hydrologic variables serve an important purpose in understanding the impact of drought on various components of the water budget. However, several continental scale, physics-based models, and large scale remote sensing products find themselves restricted in explaining the watershed scale and sub-watershed scale variability in relation to drought. This study provides a high-resolution simulation of hydrological variables for 50 watersheds in the South-Atlantic Gulf region of the Southeastern US. The high resolution hydrologic simulations provide bedrock for retrospective drought simulations and understanding the response of various hydrologic variables of these watersheds to drought. It also aids in understanding the spatial variability in the relationship, and understanding the impact of seasonality and hydroclimatology on drought. The understanding of the interplay of various water budget components at watershed scale is used in developing a reliable seasonal drought forecasting framework based on the forecasted hydrologic variables from SWAT-CFSv2 coupled models for application in real time with a lead time of 9 months
R Tools for Mesoscale Soil Hydrology
Get PDFThe book R Tools for Mesoscale Soil Hydrology is a comprehensive guide designed to equip researchers and practitioners with practical skills in geospatial data analysis using the R programming language. This material is developed to bridge the gap between theoretical soil hydrology and practical geospatial data analysis using open-source tools. As mesoscale soil hydrology increasingly relies on satellite remote sensing and large-scale environmental datasets, the ability to process, analyze, and visualize such data has become essential. This guide introduces a suite of R-based tools and workflows tailored for soil hydrology applications, with a focus on soil moisture, land-atmosphere interactions, and climate variability.
This book integrates statistical computing with geospatial science and covers a wide range of topics including basic R programming, spatial mapping, raster arithmetic, vector operations, multilayer raster analysis, and parallel geospatial computing. It emphasizes hands-on learning with open-source datasets from platforms like NASA’s SMAP, MODIS, and LANDSAT, and introduces advanced techniques such as raster reclassification, zonal statistics, and data visualization using packages like ggplot2, terra, and tidyterra. It guides users through accessing and processing satellite remote sensing data, performing statistical and spatial operations, and visualizing results for hydrological and climatological studies. Special attention is given to reproducibility, computational efficiency, and the use of parallel processing for large-scale geospatial datasets.https://repository.lsu.edu/etext/1004/thumbnail.jp
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
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