1,720,957 research outputs found
Small Sats Lifecycle Management Through MBSE Aided Decision Making Tailored Tool
Get PDFTraditional System Engineering approaches highlight some bottlenecks whenever dealing with information exchange among stakeholders, typically producing many documents, difficult to trace and to keep harmonized. This is particularly true for space applications, which entail very complex systems conceivement, design, implementation and operation by a number of different players who grow with mission complexity. Model-Based Systems Engineering (MBSE) is intended to facilitate these activities, providing a common source of truth to the system engineering “ecosystem”, improving its efficiency and quality by applying a model that evolves along the entire product lifecycle. The paper proposes a critical analysis of an MBSE approach applied to real small sat mission currently under the European Space Agency (ESA) phase A study, demonstrating its potential and its gaps. All Systems Engineering phases are explored, from the high-level mission objectives definition, through the articulated external and internal functional analysis, down to concept of operations, ending up with the Assembly, Integration and Verification/Test plan definition; every modelling step is harmonized with proper requirements generation and their role in driving the logical and physical trade-off analyzes. The study is conducted according to the ARChitecture Analysis & Design Integrated Approach (ARCADIA) and adopting the Capella tool, being very effective in mastering different engineering levels with coherence and with an iterative information refinement. Despite the clear advantage of having a unique model in which a change is inherently shared with all stakeholders, saving up time in communication, MBSE still lacks intelligent support that could strongly help in addressing the best optimal architecture in line with the system functionalities, speeding up the alternatives selection process. This would be particularly useful during the preliminary design phases, in which the almost infinite design choices are skimmed by the only systems engineers’ knowledge, who may miss some solutions. A newly approach conceived to solve this issue is here presented in the form of a decision-making tool prototype, that correlates a set of functionalities with a set of available technologies, proposing one or more architectures that are coherent with what the engineers expect from the system behaviour; a first grid of requirements is also part of the tool output, in support of the previously described MBSE approach
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Reachability Maps Generation for Opportunistic Targets Interception from Cis-Lunar Orbits
No full textTimely interception of interesting small bodies, not easily detectable quite in advance to properly prepare a space mission, still represents a bottleneck in visiting transient pristine comets and deflecting dangerous asteroids. The paper proposes a methodology to rank the celestial sphere zones in terms of reachability, having, among the control variables, the departure orbit as well; the possibility to park in cis-lunar environment, ready to depart as soon as a relevant target is detected is here supposed. Performances involved in the transfer that mostly influence preliminary mission analysis are clustered in a ranking index to support the decision making process
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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