1,720,982 research outputs found
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
Quantum reconstruction, understanding, and information: on the insight provided by reconstructing quantum theory from information-theoretic principles
Get PDFThis thesis investigates the insight gained through reconstructing quantum theory from information-theoretic principles, over three parts. I aim to establish that information-theoretic reconstructions genuinely can play an epistemic role, but that claims in the literature about what insight is generated in doing so may misrepresent the ways in which reconstruction can contribute. In particular, I argue that we should not expect to gain interpretational insight into the inner workings of quantum theory by locating its boundaries in the context of more general theories, nor should we expect to learn what quantum theory is about or endow the principles with a particular metaphysical status, since the features and principles privileged through each reconstruction are, at least to some extent, dependent on what one chooses to focus on. In carrying out reconstructions, one has the freedom to choose principles that privilege, or abstract away from, particular entities or features of quantum theory, so that quantum theory can be reframed along the lines of one’s choosing.
I take it that this latter remark: that the insight afforded by principle-theoretic reconstructions is, in some sense, a matter of capturing quantum theory from the perspective of one’s choosing, is often missed, or at least, not explicit, in the literature. However, as I’ll argue, this does not imply that reconstructions are prevented from providing any epistemic insight: instead, I’ll suggest that the perspectival nature of reconstructions can pose an advantage, providing one is mindful of it. By adopting a pragmatic, pluralist account of explanation inspired by Van Fraassen, I’ll argue that reconstructions allow one to identify explanations in terms of the features one is interested in, and by extension, also promote understanding. I’ll support this claim with my own proposal of a pragmatic, context-dependent, account of understanding, which extends the Van Fraassenian account of explanation.
The first part of the thesis considers the research program of seeking information-theoretic reconstructions of quantum theory, as well as the information-theory setting. I begin by reviewing the reconstruction program, focusing on two approaches: the black-box framework for singling out quantum correlations and the CBH reconstruction, as well as briefly highlighting other attempts. I introduce potential aims for the reconstruction program and consider ways in which principle theories generally might pose an advantage over constructive theories. I also point out some disanalogies between the historical examples of principle theories, and the principle-theoretic reconstruction program of quantum theory, and suggest that as a result, only some of the proposed aims of principle theories are met by information-theoretic reconstructions of quantum theory. Next, I discuss the concepts of information and more general uncertainty measures. I show that the common assumption that the Shannon measure is uniquely natural amongst a more general class of measures is unwarranted, since other measures receive equal justification. I also point to some problems with the claim that physics is about information. I conclude that caution is advised when calling upon information-theoretic concepts in an attempt to provide insight into the underpinnings of physical theories.
The second part consists of an in-depth case study of an example of reconstruction: the Information Causality principle, proposed to derive the Tsirelson bound, an upper limit on quantum correlations. I begin by reviewing the Information Causality game and a number of means of deriving the bound. However, I show that the correct figure is arrived at only when particular assumptions are made concerning properties of quantities that measure uncertainty. I suggest that this undermines its claim as a natural, physically motivated, principle, and proposed status as a candidate law of nature. I discuss some alternative justifications, including in terms of a deeper candidate principle, global determinism, but argue that this too fails to uniquely motivate the Information Causality principle.
The final part considers the insight gained through principle-theoretic reconstructions of quantum theory. I discuss existing claims about the role of reconstruction in more detail, focusing in particular on interpretation, explanation and understanding through principle theories in general, and information-theoretic reconstructions of quantum theory in particular. Regarding interpretation, I’ll argue that reconstructions do not in their own right offer an interpretation, nor can they contribute to or motivate interpretations, or settle realist debates. Regarding explanation, I suggest that such claims are best addressed in van Fraassen’s pragmatic framework, and I propose an extension to a pragmatic model of understanding.
I conclude that, by highlighting the unification and characterisation of quantum phenomena and aspects of quantum theory within a chosen context, allowing investigation into what distinguishes quantum theory from other theories in interesting ways, and uncovering connections that might otherwise be obscured, information-theoretic reconstructions genuinely do contribute to explanation and understanding
An analysis of relational quantum mechanics
Get PDFIn this thesis, I argue that no current version of Relational Quantum Mechanics (RQM) both meets its own goals and solves the problem of measurement, and the prospects that any such interpretation could be articulated are not promising.
I offer a clear illustration of the core framework of RQM and I note that all versions of RQM share an ontology of systems and events, where an event consists of a variable of a system taking a value relative to another system. An important difference can be drawn between versions of RQM which take the occurrence of events to be relative and those which take it to be absolute.
I argue that if RQM is to solve the measurement problem, it needs to specify the circumstances in which events occur. The primary literature does not offer such a specification, therefore I endeavour to construct one, accounting for both possibilities of the relative or absolute occurrence of events. I explore two avenues, which are suggested by plausibility as well as remarks in the primary literature.
First, I consider an intuition stated in Rovelli’s original formulation of RQM that the occurrence of an event involving two systems is indicated by the appearance of correlations in the quantum state relative to a third system. Unfortunately, I argue that this intuition fails to provide an adequate specification for the (relative or absolute) occurrence of events.
The failure of the correlation-based intuition suggests a different approach which is more in touch with physical practice and apparently favoured by recent writings on RQM, namely appealing to the structure offered by the dynamics. The development of this approach prompts a much needed discussion of the status of the dynamics in RQM and I argue that, given the basic framework of RMQ, the Hamiltonian must be conceived as relative to a system, just like the quantum state. Unfortunately, I conclude that the dynamics does not offer an adequate principle to specify the circumstances in which events (relatively or absolutely) occur.
Interestingly, some arguments indicate that for the occurrence of events to be absolute, it may be necessary to introduce a global collapse of the wavefunction or many worlds.
The search for a principle which defines the circumstances of events turns out to be mostly divorced from the question of which variable becomes determinate at each event, namely the preferred basis problem. I argue that, under the (unlikely) assumption that a plausible account of the circumstances of events is available, there are hopeful signs that a correlation-based rule coherent with RQM’s framework and aims may be formulated. However, the question of whether the rule picks out empirically adequate bases is not addressed
Observability and predictability in quantum and post-quantum physics
Get PDFI introduce a framework to distinguish two domains of physics - the manifest (i.e. the directly observable empirical records in terms of manifest configurations) and the non-manifest domain of physics (i.e. the things that the manifest configurations signify according to a physical theory). I show that many quantum 'paradoxes' rest on ambiguous reasoning about the two domains. More concretely, I study so-called 'surrealistic' trajectories, the 'delayed choice quantum eraser', and 'weak measurements'. Finally, I show how the alleged puzzles resolve in the framework provided.
I then formally define and address the question of whether quantum uncertainty could be fundamental or whether post-quantum theories could have predictive advantage whilst conforming to the Born rule on average. This notion of what I call 'empirical completeness' refers to actual prediction-making beyond the Born probabilities, and thus delineates the operational notion of predictability from a 'hidden variable' programme in quantum theory.
I study how empirical completeness connects to signal-locality, and argue that a partial proof for the impossibility of predictive advantage can be established for bi-partite quantum systems. The relevant results demonstrate signal-locality as a sufficient principle that might explain the fundamental chanciness in present and future quantum theories and, in turn, reconciles us to many quantum features as aspects of limits on Nature's predictability
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
- …
