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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
Electrical Spin Injection and Detection Using Oxide Magnetic Material Fe3O4
No full textSince the proposal of Datta-Das transistor, area of spin injection and detection is in the spotlight for the last decade. Intense research in this field has successfully tackled many issues like conductivity mismatch. Use of tunnel barrier has improved the quality of the signal. Room temperature spin signals measured using all electrical non-local geometry of measurement in materials has made it more popular. Many such demonstrations of spin injection using metallic ferromagnets like Fe, Co and CoFe into Si, GaAs and Ge promises that this technique indeed a powerful tool for many future applications.
In our study, we have used an oxide magnetic material Fe3O4 as the spin injector which has the advantage of half-metallicity for the improved electrical spin injection and detection instead of conventional materials like Fe, Co etc. 3-terminal non-local geometry of electrical measurement is adopted for electrical spin injection throughout the course of study. Spin injection and detection is successfully extended to many systems like GaAs and Si with different doping concentration in an effort to obtain a combination of right material with high spin injection efficiency. Many such systems are compared and indeed the half-metallic Fe3O4 based devices perform better than the systems with conventional materials.
Chapter 1: In this chapter a brief introduction of the area of research is provided along with a summary of earlier studies in the field. From a brief discussion on the existing theory of spin injection and diffusion in various types of materials, we can see that the proper choice of material for any such studies is important. Interface between many systems such as ferromagnet/non-magnet, ferromagnet/insulator/non-magnet are compared and analyzed using existing theories with spin-polarization as a measure. Later on the discussion is extended specifically into semiconductors as our main goal is to study the spin injection and detection into semiconducting materials. A brief discussion on the criteria and importance of the materials chosen for our study is also presented.
Chapter 2: This chapter provides a brief introduction to half-metallic Fe3O4 and its crystal structure from the magnetism point of view. An introduction to the experimental techniques used during the course of the study is also provided at the second half of the chapter.
Chapter 3: Optimization of Fe3O4 thin film growth on different substrates is mainly discussed in this chapter. Based on the choice of substrates, growth of Fe3O4 can be tuned from a single crystal to polycrystalline thin film. In the presence of MgO insertion layer, Fe3O4 growth is found to be always (100) oriented single crystalline on GaAs, whereas only (111) oriented growth of Fe3O4 is present in the absence of MgO. Similarly growth and the subsequent basic structural and magnetization characterization are presented for Fe3O4 on Si and MgO/Si. Interestingly, magnetization measurements on Fe3O4 on different substrates show an exchange bias (EB) in a single magnetic film at temperatures less than 200 K. Several temperatures dependent hysteresis together with the training effect of the samples show that the observed EB has a similar exchange pinning behavior found at the ferromagnet-antiferromagnet bi-layers. Nature of EB is found to be highly directional and the magnitude of the coupling varies at different directions with respect to the crystallographic axis of Fe3O4 grown on various substrates. A possible reason for the observation of EB in a single magnetic layer is proposed based on the formation defects at regular sites in the thin film lattice. These defects are formed during the high energy PLD growth process which alters the regular local magnetic interactions of the lattice sites. If this interaction strength is high enough to influence the total magnetization of the material, then EB can set into this system together with the low temperature magnetic anisotropy variation.
Chapter 4: This chapter furnishes the details of the optimization of the tunnel junctions for the 3-terminal non-local geometry of electrical Hanle measurement on Fe3O4/MgO/GaAs. Successful observations of room temperature electrical spin injection and detection are demonstrated on different devices with varying injection current. Hanle measurements at different low temperature show a systematic variation of spin relaxation in n-type of GaAs. Similar room temperature studies are extended to p-type GaAs, where the observation of spin signal is otherwise difficult at room temperatures. Variation of MgO barrier thickness is shown to be having no effect on the observed spin signal, which in turn avoids the ambiguity of any spurious unwanted effects from the junction region.
Chapter 5: Observation of electrical spin injection and detection in various systems are discussed in this chapter. Similar to GaAs, Hanle measurements in Fe3O4/MgO/n-type Si as well as p-type Si is carried out with the drop of spin accumulation by at least 2 orders of magnitude. The presence and the absence of MgO in Fe3O4/MgO/n-type GaAs have an impact on the magnitude of spin accumulation. Interestingly we have observed a huge enhancement of spin accumulation at T ~120K in all devices with Fe3O4 as a spin injector irrespective of the substrates. Hence the Verwey transition of Fe3O4 has an enormous influence on the spin accumulation at any substrate. Origin of the huge enhancement of the accumulation is consistent with the temperature dependence of spin-polarization of Fe3O4. From our study, we have found out that all these Fe3O4 based devices on GaAs found to be superior to the usual Fe/MgO/GaAs devices.
Chapter 6: This chapter gives a broad summary of all the studies carried out during the tenure of work. It also discusses the importance and the impact of the work in the field of semiconductor spintronics devices. Future of the extension of this work looks very promising as these devices can be directly used for the realization of spin-transistors
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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