1,721,139 research outputs found
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
Momentum Transfer due to Hypervelocity Impacts into Spacecraft Solar Arrays
No full textSpacecraft are under constant threat from hypervelocity impacts by micrometeoroids and space debris. Due to their large surface area and hence increased probability of being impacted by debris, solar arrays are of particular concern. For larger, trackable debris objects, collision avoidance manoeuvres can be performed so as the minimise the damage caused to the spacecraft structure. However, for untrackable debris, particularly among the 1-3mm size range, strikes can occur at any stage and without any prior warning. During these collisions, momentum transfer takes place whereby the initial projectile momentum is imparted to the target. Due to the Momentum Enhancement Factor (MEF) caused by ejecta being expelled from the target, the actual value of transferred momentum can vary greatly depending on the product of initial projectile momentum and this factor. In this thesis, MEF values for a range of different impact conditions and scenarios are obtained. Hypervelocity impact simulations using smoothed particle hydrodynamics discretisation form the basis of these studies, enabling high impact velocities to be simulated which would otherwise be impossible using existing test equipment. Simplified models of Hubble Space Telescope solar arrays are implemented in order to gather large amounts of data and analyse the general trends and parameters which influence the MEF. On the whole it is shown that when the projectile momentum is corrected with the MEF to yield the actual momentum transferred, it can map to a whole range of potential projectile mass/velocity/shape combinations. This data alone is not enough to distinguish between impact types, but by reducing the very coarse MEF assumptions used in prior work, the uncertainties surrounding in situ perturbation data to validate debris environment models can begin to be reduced. Europe-Colorado Mobility ProgramAerospace Engineerin
Context sensitive grammatical evolution: a novel attribute grammar based approach to the integration of semantics in grammatical evolution
No full textThe merit of Evolutionary Algorithms (EAs) as a means of automatic problem solving has been demonstrated numerous times on a diverse set of problem types across a range of different domains. The central hypothesis of this thesis is that by improving the expressiveness of EAs we can better support their deployment in domains in which context sensitive decision making is useful. After describing the principal structures and operations which allow EAs operate effectively as a general problem solving technique, we describe a sample problem and outline how two EA types, Genetic Programming (GP) and Grammatical Evolution (GE), might be configured to solve it. After some foundational elements of the discipline game design are presented, we highlight how a move towards more formal specifications of design elements presents new opportunities for the deployment of EAs as a means of Procedural Content Generation (PCG). Subsequently a set of experiments are described in which a system, designed to support encoding of data type information using a variant of GP called Strongly Typed Genetic Programming (STGP), is used to generate Player Character (PC) controllers for the digital video game Ms. Pac-Man. Following this an overview of Formal Grammars (FGs) is presented and the principal structures and operations of a third EA type, GE, are described. After which a number of more expressive FGs than Context Free Grammar (CFG), the grammar traditionally used with GE, are outlined. Finally, we outline a new GE variant designed to support usage Attribute Grammars (AGs), a means of specifying solution semantics in addition to syntax, and outline a set of experiments conducted using it. After highlighting the gains that can be made by using this GE variant in traditional problem domains such as symbolic regression, we discuss its potential as a means of PCG in digital video games.
as a means of automatic problem solving has been demonstrated numerous times on a diverse set of problem types across a range of different domains. The central hypothesis of this thesis is that by improving the expressiveness of EAs we can better support their deployment in domains in which context sensitive decision making is useful. After describing the principal structures and operations which allow EAs operate effectively as a general problem solving technique, we describe a sample problem and outline how two EA types, Genetic Programming (GP) and Grammatical Evolution (GE), might be configured to solve it. After some foundational elements of the discipline game design are presented, we highlight how a move towards more formal specifications of design elements presents new opportunities for the deployment of EAs as a means of Procedural Content Generation (PCG). Subsequently a set of experiments are described in which a system, designed to support encoding of data type information using a variant of GP called Strongly Typed Genetic Programming (STGP), is used to generate Player Character (PC) controllers for the digital video game Ms. Pac-Man. Following this an overview of Formal Grammars (FGs) is presented and the principal structures and operations of a third EA type, GE, are described. After which a number of more expressive FGs than Context Free Grammar (CFG), the grammar traditionally used with GE, are outlined. Finally, we outline a new GE variant designed to support usage Attribute Grammars (AGs), a means of specifying solution semantics in addition to syntax, and outline a set of experiments conducted using it. After highlighting the gains that can be made by using this GE variant in traditional problem domains such as symbolic regression, we discuss its potential as a means of PCG in digital video games
Search space reduction technique for constrained optimization with tiny feasible space
No full textThe hurdles in solving Constrained Optimization Problems (COP) arise from the challenge of searching a huge variable space in order to locate feasible points with acceptable solution quality. It becomes even more challenging when the feasible space is very tiny compare to the search space. Usually, the quality of the initial solutions influences the performance of the algorithm in solving such problems. In this paper, we discuss an Evolutionary Agent System (EAS) for solving COPs. In EAS, we treat each individual in the population as an agent. To enhance the performance of EAS for solving COPs with tiny feasible space, we propose a Search Space Reduction Technique (SSRT) as an initial step of our algorithm. SSRT directs the selected infeasible agents in the initial population to move towards the feasible space. The performance of the proposed algorithm is tested on a number of test problems and a real world case problem. The experimental results show that SSRT not only improves the solution quality but also speed up the processing time of the algorithm.</p
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