1,720,985 research outputs found
Probabilistic methods for improved self-consistency of Doppler Velocity Log range-based bathymetry
No full textLifelong clustering for seafloor images interpretation in AUV surveys
No full textOnline image interpretation to show habitat distribution patterns is essential for enhancing the environmental perception of Autonomous Underwater Vehicles (AUVs). Classifi-cation methods are challenging to perform because the collected images may fall outside predefined classification boundaries. Clustering, however, offers an alternative approach without relying on predefined boundaries. To enable online image interpre-tation, we propose a LifeLong Clustering (LLC) method, which incrementally clusters streaming data. Specifically, a memory bank is employed to store a sparse subset of previously collected images to reduce the computational load. Cluster merging and splitting techniques are utilized to maintain the model components adaptively, ensuring it accommodates new data while pre-serving previously learned knowledge. The clustering results on a field survey dataset demonstrate that the proposed LLC method achieves an average Normalized Mutual Information (NMI) score of 0.65 when compared to the Non-LLC method, and 0.62 when compared to other LLC results obtained from different survey paths. It highlights the robustness and reliability of the proposed method, showcasing its ability to deliver consistent clustering results across varying conditions. This consistency underscores the potential of the method to enhance AUV decision-making in real-time, enabling more informed and efficient operations.</p
Probabilistic methods for improved self-consistency of Doppler Velocity Log range-based bathymetry
No full textWe develop a probabilistic approach to improve the self-consistency of Doppler Velocity Log (DVL) derived bathymetric maps that models the interactions of acoustic beams with uneven seafloors. DVLs measure velocity and altitude over the seafloor using Doppler shift and time-of-flight (TOF) of reflected acoustic signals, and are integral to underwater vehicle navigation. The proposed method combines acoustic propagation and reflection theory with Gaussian process regression (GPR) to model terrain bias in DVL range measurements. We compare three bathymetric mapping methods using DVL range data gathered during field trials with the University of Southampton’s Smarty200 AUV. Our results demonstrate that accounting for terrain bias improves the self-consistency of maps, implying potential use of this method to identify loop closures for enhanced underwater navigation
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
- …
