1,720,984 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    γ-spectroscopic determination of mean lifetimes and magnetic moments of excited nuclear states

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    The mean lifetime of an excited nuclear state is an important observable directly related to the transition probability. Information on the mean lifetimes of nuclear excited states can give insight into the evolution of the nuclear shape as a function of nucleon number. For this work, mean lifetimes of the rare-earth isotopes 174,176,178,180Hf and 152Gd have been measured. The mean lifetimes have been determined with the fast-timing technique, already introduced in the 1950s, but applicable to a wider range of excited nuclear states, due to rapid progress in the development of new scintillation detectors in the last two decades. Both experiments have been performed at the FN Tandem accelerator of the IFIN-HH with the ROSPHERE detector array. A possible new signature for the known quantum phase transition at N=90 has been established with the results from the 152Gd experiment and the correlation to other observables, such as the E0 transition strength, has been investigated. The evolution of collectivity and the rotational structure of the hafnium isotopes have been investigated and a maximum of the collectivity at N=100 has been identified. In total 13 mean lifetimes have been determined for the 174,176,178,180Hf isotopes. The nuclear magnetic dipole moment is an important indicator of the composition of the proton neutron wave function, and therefore the single particle properties of the nuclear state. The second part of this thesis presents the results from a g-factor measurement of the 2+1 state of 18O with the recently developed ECR-TDRIV technique. The method is in particular foreseen for the application to radioactive ion beams, but has to be tested with stable beams. The analysis procedure of the 18O experiment is outlined and the results for the g factor are compared to previous measurements and shell model calculations

    Confined ensembles of highly charged ions for studies of light-matter interaction at high intensities : the HILITE Penning trap setup

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    The investigation of light-matter interactions is based on the description of the ‘photoelectric effect’ in the early 20th century. The development of the first laser systems, especiallyof systems with high intensities and/or high photon energies allowed science to enter new interaction regimes. Previously unknown, non-linear effects like multiphoton ortunnel ionisation processes occurred and became subject of theoretical descriptions and experimental studies. Independently, the storage techniques for charged particles (electrons and ions) developed in parallel and different kind of devices, like Paul and Penning traps, had been invented in the 1950s and 1960s to study fundamental parameters of matter (for instance g-factor, mass etc.) with previously unknown accuracy. Thereby, they were able to verify predictions given by the Standard Model. The HILITE experiment (High-Intensity Laser Ion T rap Experiment), presented within this thesis, is designed to combine and use for the first time the advantageous properties of target preparation a Penning trap can provide, like ensemble temperature, purity and localizability, in order to investigate laser-ion interactions at high intensities. Particular attention was paid to the compactness of the setup in order to be capable to transport the experiment to different laser facilities and perform experiments on site. According to therequirements (high intensities or high photon energies) of the experimental question, their selection is done. By knowing the target properties before the laser irradiation, for instancethe charge state, precisely, allows theory to reduce the amount of occurring interactions and by that a ‘simpler’ description. Theoretical predictions of physical quantities, like ionisationcross sections, can therefore be linked better to the experimental data. In the frame of this thesis, the experimental setup was built and put into operation in terms of its dedicated ion source, ion selection, beam transport, deceleration and capture inside the Penning trap at the GSI Helmholtzzentrum für Schwerionenforschung GmbH. During commissioning, the storage and non-destructive detection of pure ion ensembles within the trap was demonstrated. The individual components have been characterised and their operation was checked. Additionally, a propsal was handed in for the first beamtime at an external laser facility (FLASH at DESY), which was granted and carried out. The interaction between the laser and low charged ions could be verified. Unfortunately an unexpected high background pressure prevented the measurement of the previously planned ion species. Due to the experiences gained, some improvements and adaptions are planned or have been already implemented for future laser experiments

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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
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