1,720,962 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
PREUČEVANJE ULTRA HITRE DINAMIKE ELEKTRONOV V KORELIRANIH SISTEMIH S POMOČJO ČASOVNO LOČLJIVE FOTOEMISIJE
Full text linkComplex systems in condensed matter are characterized by strong coupling
between different degrees of freedom constituting a solid. In materials
described by many-body physics, these interactions may lead to
the formation of new ground states such as excitonic insulators, Mott
insulators, and charge and spin density waves. However, the inherent
complexity in such materials poses a challenge to identifying the
dominant interactions governing these phases using equilibrium studies.
Owing to the distinct timescales associated with the elementary interactions,
such complexities can be readily addressed in the non-equilibrium
regime. Additionally, these materials might also show the emergence
of new, metastable “hidden“ phases under non-equilibrium. The thesis
investigates the ultrafast timescales of fundamental interactions in candidate
systems by employing time-and angle-resolved photoemission spectroscopy
in the femtosecond time domain. In the (supposed) excitonic
insulator model system Ta2NiSe5, the timescale of band gap closure
and the dependence of rise time (of the photoemission signal) on the
photoexcitation strength point to a predominantly electronic origin of
the band gap at the Fermi level. The charge density wave (CDW) -
Mott insulator 1T-TaS2 undergoes photoinduced phase transition to two
different phases. The initial one is a transient phase which resembles
the systems’s high temperature equilibrium phase, followed by a long-lived
“hidden“ phase with a different CDW amplitude and is primarily
driven by the CDW lattice order. For the spin density wave system
CaFe2As2 where multiple bands contribute in the formation of Fermi surfaces,
selective photoexcitation was used to disentangle the role played
by different electron orbitals. By varying the polarization of photoexcitation
pulses, it is observed that dxz/dyz orbitals primarily contribute to
the magnetic ordering while the dxy orbitals have dominant role in the
structural order. The findings of the present study provide deeper perspectives
on the underlying interactions in complex ground phases of
matter, therefore, initiating further experimental and theoretical studies
on such materials.Za kompleksne sisteme v kondenzirani snovi je značilna močna sklopitev
med različnimi prostostnimi stopnjami, ki to snov tvorijo. V materialih,
ki jih opisuje fizika več teles, lahko takšne interakcije vodijo v nastanek
novih osnovnih stanj, kot so ekscitonski in Mottovi izolatorji ter valovi
gostote naboja in spina. Zaradi zapletene narave takšnih sistemov lahko
z ravnovesnimi študijami le stežka prepoznamo prevladujoče interakcije
v omenjenih fazah. Po drugi strani pa lahko zaradi prisotnosti različnih
karakterističnih časovnih skal kompleksne materiale lažje obravnavamo
z nerovnovesnimi tehnikami. Poleg tega lahko v neravnovesju v omenjenih
materialih pride do pojava novih, metastabilnih t.i. skritih stanj.
V disertaciji smo raziskali ultra hitre časovne skale osnovnih interakcij
v omenjenih sistemih z uporabo femtosekundne kotno ločljive fotoemisijske
spektroskopije. V (domnevnem) ekscitonskem izolatorju Ta2NiSe5
karakteristični čas, v katerem se zapre energijska vrzel, ter odvisnost karakteristi
čnega časa dviga fotoemisijskega signala od jakosti svetlobnega
vzbujanja kažeta na to, da je energijska vrzel v omenjenem materialu
elektronskega izvora. V Mottovem izolatorju 1T-TaS2, v katerem so prisotni
valovi gostote naboja (ang. charge density wave - CDW) pride pri
fotovzbujanju do prehoda v različne neravnovesne faze in sicer najprej
v neravnovesno stanje, ki je podobno visoko temperaturnem ravnovesnem
stanju in nato v dolgoživo “skrito“ stanje z manjšo CDW amplitudo,
pričemer je gonilna sila teh prehodov kristalni red CDW. V vzorcih
CaFe2As2, za katere so značilni valovi gostote spina in kjer več energijskih
pasov prispeva k nastanku Fermijeve površine, smo s selektivnim
fotovzbujanjem ugotavljali kakšna je vloga različnih orbital. S spreminjanjem
polarizacije vzbujevalnih sunkov smo opazili, da dxz/dyz orbitale
primarno prispevajo k magnetnemu urejanju, medtem ko imajo dxy orbitale
glavno vlogo v strukturnem redu. Ugotovitve te študije ponujajo
nov vpogled v temeljne interakcije v kompleksnih materialih in predstavljajo
osnovo za nadaljnje eksperimentalne in teoretične raziskave
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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