1,720,957 research outputs found
Geological realism control in the process of oil and gas field models automatic history matching
Full text linkHistory matching and uncertainty quantification of reservoir performance with generative deep learning and graph convolutions
No full textThis research tackles the challenges faced in geological modelling under uncertainty to
flow profiling and history matching. Geological uncertainty encompasses various interpretations that may be consistent with the available data. When it comes to modelling,
these interpretations necessitate different modelling approaches and configurations. As a
result, it becomes challenging to effectively define the space of models and their parameters, as the problem’s dimensionality constantly changes. To overcome this challenge,
the study proposes an innovative approach that involves parameterisation through implicit
low-dimensional hidden spaces.
The study recognises the need to consider uncertainty in geological scenarios, structural
uncertainty, and petrophysical dependencies. These factors play a crucial role in accurately
representing and predicting the behaviour of geological objects. The chosen methodology
is the Graph Variational Autoencoder approach, which allows for the parameterisation of
the prior set of geological representations while considering various uncertainty.
The main idea behind this approach is to utilise an Encoder to map the original prior set into
a latent space that implicitly describes the prior. The latent space and the Decoder act as
a generator that can search for realisations that meet specific requirements. This methodology enables the estimation of uncertainty in dynamic response and history matching,
enhancing the overall understanding of geological systems.
The study justifies and presents a transition to graph-based generative modelling. I will
show that geometric deep learning, in particular graph convolutions, is the most convenient
method to account for geological representations with generative models. This transition
is motivated by the need to handle non-Euclidean data types, specifically those lacking
a strict structure. This enables the consideration of the structural and spatial features of
the reservoir by moving away from the classical lattice representation. The transition expands the applicability of generative models to a broader range of geological objects and
enhances the realism of the generated representations, as conventional approaches have
limitations and cannot describe the complex structural features of reservoirs or irregularities in flow behaviour.
The study employs advanced analytics tools to gain a deeper understanding of the hidden
spaces within the generative models. These tools provide valuable insights into the internal
structure of hidden spaces, allowing for a more informed analysis of the generative models’
capabilities and limitations.
Moreover, the study introduces a geodesic metric for efficient navigation in high-dimensional
hidden spaces. This metric enables more effective exploration and interpolation within
the hidden space, resulting in a more predictable behaviour than the standard Euclidean
metric. The geodesic metric also serves as the foundation for controlling the geological realism in the latent space, ensuring that the generated realisations maintain their geological
coherence.
To test the generative capabilities of a graph-based generative model, the study develops
three prior datasets of 3D geological objects, focusing on the uncertainty of geological
scenarios, structural uncertainty, and the semi-synthetic Brugge field dataset, which represents four different stratigraphic zones. These datasets serve as test cases to evaluate the
effectiveness and limitations of the proposed generative models
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
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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