1,721,026 research outputs found
Probabilistic forecasting of hydraulic fracturing-induced seismicity using an injection-rate driven etas model
No full textThe development of robust forecasts of human-induced seismicity is highly desirable to mitigate the effects of disturbing or damaging earthquakes. We assess the performance of a well-established statistical model, the epidemic-type aftershock sequence (ETAS) model, with a catalog of ∼93;000 microearthquakes observed at the Preston New Road (PNR, United Kingdom) unconventional shale gas site during, and after hydraulic fracturing of the PNR-1z and PNR-2 wells. Because ETAS was developed for slower loading rate tectonic seismicity, to account for seismicity caused by pressurized fluid, we also generate three modified ETAS with background rates proportional to injection rates. We find that (1) the standard ETAS captures low seismicity between and after injections but is outperformed by the modified model during high-seismicity periods, and (2) the injection-rate driven ETAS substantially improves when the forecast is calibrated on sleeve-specific pumping data. We finally forecast out-of-sample the PNR-2 seismicity using the average response to injection observed at PNR-1z, achieving better predictive skills than the in-sample standard ETAS. The insights from this study contribute toward producing informative seismicity forecasts for real-time decision making and risk mitigation techniques during unconventional shale gas development
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
Earthquake seismology 2016/2017 : BGS Seismic Monitoring and Information Service : Twenty-eighth Annual Report
Full text linkThe British Geological Survey (BGS) operates a network of seismometers throughout the UK in order to acquire seismic data on a long-term basis. The aims of the Seismic Monitoring and Information Service are to develop and maintain a national database of seismic activity in the UK for use in seismic hazard assessment, and to provide near-immediate responses to the occurrence, or reported occurrence, of significant events. The project is supported by a group of organisations under the chairmanship of the Office for Nuclear Regulation (ONR) with major financial input from the Natural Environment Research Council (NERC).
In the 28th year of the project, we have continued to operate the national seismic monitoring network efficiently and effectively. Real-time data from all stations were transferred directly to Edinburgh for near real-time detection and location of seismic events as well as archival and storage of continuous data. Data latency was generally low, less than one minute most of the time, and there was a high level of completeness within our archive of continuous data.
All significant events were reported rapidly to the Customer Group through seismic alerts sent by e-mail. The alerts were also published on the Internet (http://www.earthquakes.bgs.ac.uk).
Three papers have been published in peer-reviewed journals. Four presentations were made at international conferences. Five BGS reports were prepared along with three external reports. We have continued to collaborate widely with academic partners across the UK and overseas on a number of research initiatives
UK earthquake monitoring 2009/2010
Full text linkThe British Geological Survey (BGS) operates a network of seismometers
throughout the UK in order to acquire seismic data on a long-term basis.
The aims of the Seismic Monitoring and Information Service are to develop
and maintain a national database of seismic activity in the UK for use in
seismic hazard assessment, and to provide near-immediate responses to
the occurrence, or reported occurrence, of significant events. The project is
supported by a group of organisations under the chairmanship of the
Department of Communities and Local Government (DCLG) with major
financial input from the Natural Environment Research Council (NERC).
In the 21st year of the project, seven new broadband seismograph stations
were established, giving a total of thirty broadband stations. Real-time data
from all broadband stations and nearly all other short period stations are
being transferred directly to Edinburgh for near real-time detection and
location of seismic events as well as archival and storage of continuous
data. Four of the broadband stations were installed as part of site-specific
monitoring project around Oldbury-on-Severn. We have purchased a further
five broadband sensors and high dynamic range digitisers as well as five
strong motion accelerometers.
All significant events were reported rapidly to the Customer Group through
seismic alerts sent by e-mail. The alerts were also published on the Internet
(http://www.earthquakes.bgs.ac.uk). Monthly seismic bulletins were issued
six weeks in arrears and compiled in a finalized annual bulletin (Galloway,
2010). In all reporting areas, scheduled targets have been met or
surpassed.
Ten papers have been published in peer-reviewed journals. Twenty-two
presentations were made at international conferences. Three BGS internal
reports were prepared along with five confidential reports. We have
continued to collaborate widely with academic partners across the UK and
overseas on a number of research initiatives
UK Earthquake Monitoring 2013/2014
Full text linkThe British Geological Survey (BGS) operates a network of seismometers throughout the UK in order to acquire seismic data on a long-term basis. The aims of the Seismic Monitoring and Information Service are to develop and maintain a national database of seismic activity in the UK for use in seismic hazard assessment, and to provide near-immediate responses to the occurrence, or reported occurrence, of significant events. The project is supported by a group of organisations under the chairmanship of the Office for Nuclear Regulation (ONR) with major financial input from the Natural Environment Research Council (NERC).
In the 24th year of the project, two new broadband seismograph stations were established, giving a total of 42 broadband stations. Real-time data from all stations are being transferred directly to Edinburgh for near real-time detection and location of seismic events as well as archival and storage of continuous data. Data latency is generally low, less than one minute most of the time, and there is a high level of completeness within our archive of continuous data.
All significant events were reported rapidly to the Customer Group through seismic alerts sent by e-mail. The alerts were also published on the Internet (http://www.earthquakes.bgs.ac.uk). Monthly seismic bulletins were issued six weeks in arrears and compiled in a finalised annual bulletin (Galloway, 2014).
Ten papers have been published in peer-reviewed journals. Three presentations were made at international conferences. Two BGS reports were prepared along with six confidential reports. We have continued to collaborate widely with academic partners across the UK and overseas on a number of research initiatives
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
- …
