130,610 research outputs found
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Combining experimental volcanology, petrology and geophysical monitoring techniques
No full textIn general, an understanding of the complex processes acting before and during volcanic eruptions is approached from various different sides, e.g. laboratory experiments on fragmentation and/or bubble burst eruption mechanisms, petrological analysis of the eruptive products and various geophysical monitoring and source localization techniques. Each of these techniques can deliver valuable insights by adding pieces of information about the physical processes that drive the volcanic activity. However, often studies are focussing on a single aspect of the process, without setting the results in a more general context. Often, this strategy is absolutely valid, when the focus is laid on a single piece in the complex chain of processes taking place in volcanic eruptions. This must fail when the results
aim to suggest a valid model for the combined observations at volcanoes using the above described techniques. The resulting models of volcanic source mechanisms and eruptive
features can therefore lead to biased assumptions. This study aims to close this gap between laboratory experiments, petro-chemical analysis and modern geophysical monitoring and source localization techniques in a case study of Mt. Yasur (Vanuatu) volcano.
The presented laboratory experiments on explosive volcanic eruptions upon rapid decompression show that decompression rate is the dening parameter in the experiments and that
a scaling to large-scale processes is valid. Furthermore, a model is presented that correlates measured particle velocities to decompression rate and initial gas-overpressure. This model is used to estimate source volumes and overpressures at Volcan de Colima (Mexico) and Mt. Yasur (Vanuatu).
A petrographically and geochemically characterization of Mt. Yasurs eruptive products suggests a shallow magma-mingling process at both of Mt. Yasurs active craters, perhaps due to rejuvenation of material slumped from the crater walls into an open conduit system. A study on the time-reversal imaging technique and its ability to detect the details of finite rupture (or time-variant) processes shows that the limitations of TR imaging start where the source stops being point-localised with respect to the used wavelength.
Inversion of the source mechanisms of Strombolian explosions at Mt. Yasur are performed using a multi-parameter dataset consisting of seismic, acoustic and Doppler-radar data. Time-reversal imaging and moment tensor inversion are used to invert the source location of the seismic long-period (f < 1Hz) signals, which is supposed to refl
ect
fluid movement at depth. The source is located in the north-east of the crater region in a depth of several
hundred meters. Furthermore, the source volume of the radiated infrasound signals is estimated from fundamental resonance frequencies. The results showed that the maximum
particle velocity measured with the Doppler radar correlates nicely with the estimated source volumes lengths. The inverted seismic moment does not show any correlation with the estimated slug sizes, i.e. the slug size does not map in seismic moment. This is an
important information, as it states that a larger source volume does not necessarily produces a larger seismic moment.
From these combined results, a common feeder system for all active craters at Mt. Yasur is proposed. The differences in event recurrence rate at the three active craters are believed to be controlled by either the conduit geometry or variations in degassing or cooling rate.
Strombolian-type eruptions at Mt. Yasur are suggested to be due to the burst of gas slugs with lengths and overpressures comparable to volcanoes showing similar eruptive patterns.
The results illustrate the importance of combined studies that overcome the limitations of single disciplines. In this way, a more comprehensive view of volcanic eruptions and the associated observations is possible. Such a multi-disciplinary approach will contribute to a better understanding of volcanic processes and the associated hazards
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Effects of forcing differences and initial conditions on inter-model agreement in the VolMIP volc-pinatubo-full experiment
No full textThis paper provides initial results from a multi-model ensemble analysis based on the volc-pinatubo-full experiment performed within the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP) as part of the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The volc-pinatubo-full experiment is based on an ensemble of volcanic forcing-only climate simulations with the same volcanic aerosol dataset across the participating models (the 1991-1993 Pinatubo period from the CMIP6-GloSSAC dataset). The simulations are conducted within an idealized experimental design where initial states are sampled consistently across models from the CMIP6-piControl simulation providing unperturbed preindustrial background conditions. The multi-model ensemble includes output from an initial set of six participating Earth system models (CanESM5, GISS-E2.1-G, IPSL-CM6A-LR, MIROC-E2SL, MPI-ESM1.2-LR and UKESM1). The results show overall good agreement between the different models on the global and hemispheric scales concerning the surface climate responses, thus demonstrating the overall effectiveness of VolMIP's experimental design. However, small yet significant inter-model discrepancies are found in radiative fluxes, especially in the tropics, that preliminary analyses link with minor differences in forcing implementation; model physics, notably aerosol-radiation interactions; the simulation and sampling of El Niño-Southern Oscillation (ENSO); and, possibly, the simulation of climate feedbacks operating in the tropics. We discuss the volc-pinatubo-full protocol and highlight the advantages of volcanic forcing experiments defined within a carefully designed protocol with respect to emerging modelling approaches based on large ensemble transient simulations. We identify how the VolMIP strategy could be improved in future phases of the initiative to ensure a cleaner sampling protocol with greater focus on the evolving state of ENSO in the pre-eruption period
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
The R&D Tax Incentives
No full textThis article sets out some background information and reflections of the author on the R&D tax incentive schemes included in the Common Corporate Tax Base (CCTB) Proposal. In particular the author analyzes the stimulus to private R&D through ad hoc tax incentives included in the CCTB Proposal and dives into the actual provisions included in the Proposal highlighting the most relevant issues connected with their design and interpretation. Moreover, the author explores the interaction between the CCTB Proposal and the granting by Member States of domestic R&D tax incentives
Effects of forcing differences and initial conditions on inter-model agreement in the VolMIP volc-pinatubo-full experiment
No full textInternational audienceThis paper provides initial results from a multi-model ensemble analysis based on the volc-pinatubo-full experiment performed within the Model Intercomparison Project on the climatic response to volcanic forcing (VolMIP) as part of the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The volc-pinatubo-full experiment is based on ensemble of volcanic forcing-only climate simulations with the same volcanic aerosol dataset across the participating models (the 1991-1993 Pinatubo period from the CMIP6-GloSSAC dataset). The simulations are conducted within an idealized experimental design where initial states are sampled consistently across models from the CMIP6-piControl simulation providing unperturbed pre-industrial background conditions. The multi-model ensemble includes output from an initial set of six participating Earth system models (CanESM5, GISS-E2.1-G, IPSL-CM6A-LR, MIROC-E2SL, MPI-ESM1.2-LR and UKESM1).The results show overall good agreement between the different models on the global and hemispheric scale concerning the surface climate responses, thus demonstrating the overall effectiveness of VolMIP’s experimental design. However, small yet significant inter-model discrepancies are found in radiative fluxes especially in the tropics, that preliminary analyses link with minor differences in forcing implementation, model physics, notably aerosol-radiation interactions, the simulation and sampling of El Niño-Southern Oscillation (ENSO) and, possibly, the simulation of climate feedbacks operating in the tropics. We discuss the volc-pinatubo-full protocol and highlight the advantages of volcanic forcing experiments defined within a carefully designed protocol with respect to emerging modeling approaches based on large ensemble transient simulations. We identify how the VolMIP strategy could be improved in future phases of the initiative to ensure a cleaner sampling protocol with greater focus on the evolving state of ENSO in the pre-eruption period
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