1,720,960 research outputs found
Prototyping of Lunar surface geological sampling tools for Moon spacewalk simulations by ESA
No full textApollo Lunar missions returned to scientists on Earth the first collection of geological extra-terrestrial planetary
samples, other than meteorites. Scientists around the world are still studying rocks and soil samples that were
collected, by the Apollo 11 through 17 missions, using modern equipment, methods and technologies. The return of samples has allowed the field of planetary science to advance in ways unthinkable with the restrictions of in-situ analysis and remote observations.
As for every other aspect of the Apollo programme, the design and manufacturing of the tools utilized by
astronauts for sample collection had to meet rigorous planetary protection requirements, whilst respecting stringent environmental and operability constraints. Many of those tools went through various redesign efforts, based on feedback from the very skillful and resourceful astronauts using them. In future planetary exploration missions, geological and geo-microbiological sampling will be a key to further development of our understanding of the evolution of the solar system, and to develop successful technologies for in-situ resource utilization and 3D printing. Designing and manufacturing technologies and ergonomics have developed since the 1960s, and so have chemical and biological hazard containment protocols, and analytical tools. Whilst it is important to solidly build on the lessons learned in the Apollo era, there is a serious opportunity for innovative design solutions. The European Space Agency (ESA) Neutral Buoyancy Facility (NBF) based in the European Astronaut Centre (EAC) in Cologne has a large experience in performing 0g simulations for ISS (International Space Station) Extra Vehicular Activities (EVA), and has recently engaged in simulations of Lunar surface operations, replicating reduced gravity and mobility constraints, in order to prepare future human and robotics surface operations. One of the main objectives within this area is prototyping and testing new geological sampling tools which could be used in future human surface Lunar missions. The tools are being developed in cooperation with the team of planetary geologists of the PANGAEA project (Planetary ANalogue Geological and Astrobiological Exercise for Astronauts), and field tested during the PANGAEA Space Analogue test campaigns.
This paper discusses the requirements and objectives to be met while developing such tools, the challenges
related to EVA suits and Lunar environment which impact the astronauts’ mobility and tools performance. It presents the status of development achieved during NBF and PANGAEA analogue field testing. The examples include a variety of sample collectors, containers, markers and the outcome of test performed in various mission scenarios
A random forest approach to quality-checking automatic snow-depth sensor measurements
Full text linkState-of-the-art snow sensing technologies currently provide an unprecedented amount of data from both remote sensing and ground sensors, but their assimilation into dynamic models is bounded to data quality, which is often low – especially in mountain, high-elevation, and unattended regions where snow is the predominant land-cover feature. To maximize the value of snow-depth measurements, we developed a random forest classifier to automatize the quality assurance and quality control (QA/QC) procedure of near-surface snow-depth measurements collected through ultrasonic sensors, with particular reference to the differentiation of snow cover from grass or bare-ground data and to the detection of random errors (e.g., spikes). The model was trained and validated using a split-sample approach of an already manually classified dataset of 18 years of data from 43 sensors in Aosta Valley (northwestern Italian Alps) and then further validated using 3 years of data from 27 stations across the rest of Italy (with no further training or tuning). The F1 score was used as scoring metric, it being the most suited to describe the performances of a model in the case of a multiclass imbalanced classification problem. The model proved to be both robust and reliable in the classification of snow cover vs. grass/bare ground in Aosta Valley (F1 values above 90 %) yet less reliable in rare random-error detection, mostly due to the dataset imbalance (samples distribution: 46.46 % snow, 49.21 % grass/bare ground, 4.34 % error). No clear correlation with snow-season climatology was found in the training dataset, which further suggests the robustness of our approach. The application across the rest of Italy yielded F1 scores on the order of 90 % for snow and grass/bare ground, thus confirming results from the testing region and corroborating model robustness and reliability, with again a less skillful classification of random errors (values below 5 %). This machine learning algorithm of data quality assessment will provide more reliable snow data, enhancing their use in snow 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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