1,720,997 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
Linking challenge and hindrance stress to safety performance: The moderating effect of core self-evaluation
No full textThe buffering effect of core self-evaluation (CSE) in stress research has received academic attention. However, most research in this area focused on its moderating effect on well-being. In the present study, we take a closer look at the moderating role of CSE in the relationship between challenge/hindrance stress and safety performance. Results indicated that challenge and hindrance stress were both negatively related to safety performance. More importantly, CSE acted as a buffer in the negative relationships between challenge stress and safety compliance and between hindrance stress and safety participation. Contrary to our prediction, the negative relationship between hindrance stress and safety participation was stronger for people higher on CSE. Based on our findings, we discuss the theoretical implications for personality and safety research. (C) 2014 Elsevier Ltd. All rights reserved
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
Silicon photonic subwavelength gratings for dense photonic integration and polarization control
No full textSilicon photonics is a promising optical chip platform, providing a low-cost solution with large-scale photonic integrated circuits. Advances in silicon photonics demand a high-density chip integration, but it is challenged by the optical crosstalk. In recent years, subwavelength gratings (SWGs) forming anisotropic metamaterials have been proposed to manipulate wave behaviors, shrinking the chip footprint and enhancing the device performance. In this thesis, I explore the fundamentals of SWG metamaterials and utilize those properties to enhance photonic device performance. First, exceptional coupling that completely suppresses the crosstalk between closely spaced waveguides is achieved. Anisotropic dielectric perturbation, introduced by SWG metamaterials, is the key to achieving such phenomena, drastically increasing the chip integration density. Second, SWGs are used for designing mode-evolution-based polarization beam splitter (PBS). Due to the reduced skin-depth via SWGs and adiabatic transition, ultra-broadband PBS is achieved with a high fabrication tolerance. Third, by engineering the coupling behaviors with SWGs, a broadband polarization splitter-rotator (PSR) via mode evolution is designed. The SWGs induce a large coupling strength that reduces the modal conversion length, while adiabatic transition allows a broad bandwidth and a large fabrication tolerance. Additionally, a heterogeneous photonic structure is designed to achieve extremely high group velocity dispersion (GVD). The analytical representation of the induced GVDs is presented, with their engineering capability in coupling wavelengths and dispersion peaks. To conclude, I discuss the potential research directions utilizing the SWG metamaterials and summarize my outlook for future silicon photonics.Embargo status: Restricted until 09/2023. To request the author grant access, click on the PDF link to the left
Subwavelength Grating Metamaterials for Silicon Photonic Sensing and Polarization Splitting
No full textSilicon photonics is an emerging technology platform that controls light on a silicon chip to develop photonic integrated circuits (PIC). Silicon photonics is playing a mainstream role in high-speed and energy-efficient data center interconnect, optical computing architectures, next-generation artificial intelligence hardware, quantum technologies, and bio-chemical sensing. In the last century, we have seen how electronics have changed our lives through continuous performance improvement and miniaturization of devices. Similarly, to harness the benefits of integrated photonics, significant efforts have been made towards improving the individual component performances and reducing the footprint of silicon PIC. Among the approaches, utilizing subwavelength grating (SWG) structures is an attractive one as it provides a flexible tool to alter material properties via the geometry of the device and cladding region. In this dissertation, SWG metamaterial will be used to demonstrate waveguide crosstalk suppression to reduce device footprint and to demonstrate high performance and compact polarization beam splitter and refractive index sensor. First, I will introduce the anisotropic properties of subwavelength grating arranged in parallel to the propagation direction in the cladding region known as extreme skin depth (eskid) waveguide to address the crosstalk of coupled waveguides in transverse electric (TE) mode and the experimental demonstration of complete suppression of crosstalk. Then an on-chip delay line, an essential component for optical signal processing, will be demonstrated with a reduced footprint requirement, and the measurement aspect of such a delay line will be discussed. Then, SWG metamaterial cladding will be utilized to introduce a large birefringence along with complete suppression of crosstalk to design and experimentally demonstrate an ultrahigh extinction ratio polarization beam splitter (PBS). This PBS can achieve an ultrahigh extinction ratio simultaneously for both TE and TM polarization in the same wavelength range. This type of ultrahigh extinction ratio PBS will be important for applications where a high degree of polarization distinguishability is required, such as polarization-encoded qubit processing. Finally, the SWG cladding will be arranged perpendicular to the direction of propagation to provide additional field components and to achieve zero crosstalk points with liquid cladding for transverse magnetic (TM) mode. A compact cladding refractive index sensor will be demonstrated where both wavelength and intensity change can be monitored in response to the cladding index change for a wide index range. This type of sensor will be more suitable for fixed wavelength intensity sensing schemes which are convenient to implement for bio-chemical sensing and point-of-care applications.Embargo status: Restricted until 01/2174. To request the author grant access, click
on the PDF link to the left
- …
