128,787 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Critical Points for Non Differentiable Functionals
No full textIn this paper we deal with the existence and multiplicity of critical points for non differentiable integral functionals defined in the Sobolev space W1,p(Ω) (p > 1) by:
0
where Ω is a bounded open set of RN, with N ≥ 3 and p ≤ N. Under natural assump- tions F turns out to be not Frech ́et differentiable on W1,p(Ω), thus classical critical
point theory cannot be applied. The existence of a critical point of F has been proved in [1] by means of a suitable extension of the Ambrosetti-Rabinowitz minimax result. Here we get existence and multiplicity of critical points of F applying a generalization of a symmetric version of the Mountain-Pass theorem proved in [10]. We will follow the same procedure of [7] where the quasilinear case has been treated
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Orthographic input and phonological representations in learners of Chinese as a foreign language.
No full textThis paper provides evidence that the second language orthographic input affects the mental representations of L2 phonology in instructed beginner L2 learners. Previous research has shown that orthographic representations affect monolinguals' performance in phonological awareness tasks; in instructed L2 learners such representations could also affect pronunciation. This study looked at the phonological representations of Chinese rimes in beginner learners of Chinese as a foreign language, using a phoneme counting task and a phoneme segmentation task. Results show that learners do not count or segment the main vowel in those syllables where it is not represented in the pinyin (romanisation) orthographic representations. It appears that the pinyin orthographic input is reinterpreted according to L1 phonology-orthography correspondences, and interacts with the phonological input in shaping the phonological representations of Chinese syllables in beginner learners. This explains previous findings that learners of Chinese do not pronounce the main vowel in these syllables
Multiple critical points for nondifferentiable functionals involving Hardy potentials
No full textIn this paper we study general functionals of the calculus of variations with the presence of a Hardy potential. We will improve several results obtained in the semilinear framework. We will first prove a general weak lower
semicontinuity result, which will imply the existence of a minimum point whenever the functional is coercive. Then we will demonstrate existence and multiplicity results of critical points, even if our functional is not differentiable. We will apply a nonsmooth critical point theory developed in Corvellec et al. (Nonlinear Anal. 1 (1993) 151) and Degiovanni and Marzocchi (Ann. Mat. Pura Appl. 167 (1994) 73)
Censorship and Orwell’s legacy: Interview with Jean Seaton
No full textCensorship and Orwell’s Legacy: An interview with Jean Seaton, questions by Benedetta Brevin
The arrival of the new coronavirus in the era of chronic degenerative diseases
No full textIl 9 gennaio 2020, il Chinese Centre for Disease Control ha identificato un nuovo Coronavirus, SARSCoV- 2, come agente responsabile del Covid-19. In circa due mesi il virus si e diffuso in tutto il mondo e l’11 marzo l’Organizzazione Mondiale della Sanita ha dichiarato il Covid-19 pandemia. L’Italia e stato il primo Paese europeo a esserne duramente colpito. Al suo arrivo, il virus ha trovato una popolazione con eta media elevata e alta prevalenza di patologie croniche. Questo ha aumentato la letalita e gravita del Covid-19 e, a sua volta, l’emergenza sanitaria che ne e derivata rischia di peggiorare gli esiti delle malattie croniche gia esistenti. E fondamentale analizzare fin da subito gli effetti collaterali della pandemia su altre patologie, per valutarne la portata e l’impatto. Utilizzando le conoscenze che abbiamo accumulato nel tempo e acquisito in queste settimane si potranno anticipare alcuni dei bisogni sanitari futuri e limitare gli effetti indiretti negativi di Covid-19
Quasi--Linear equations on R^N: Perturbation Results
No full textIn this paper we prove existence of nontrivial solutions for the quasi-linear elliptic problem
{div((I + epsilonA(x, u))delu) + u + epsilonH(x, u,delu) = \u\(p-1), in R-N, u is an element of H-1(R-N) boolean AND W-2,W-q (R-N), q > N
where 1 2 and the operator -div((I + epsilonA(x, u))delu) +epsilonH(x, u, delu) is a perturbation of the Laplacian. We use a perturbation method recently developed in [1], [2], [3] and we get results both in the variational and in the non-variational framework
Critical Points for Some Functionals of the Calculus of Variations
No full textIn this paper we prove the existence of critical
points of non differentiable functionals of the kind
J(v)=\frac_\Omega A(x,v)\nabla v\cdot\nabla v-\frac1{p+1}\int_\Omega
(v^+)^{p+1},
where , if and
stands for the positive part of the function . The
coefficient is a Carathéodory matrix
derivable with respect to the variable . Even if both
and are uniformly bounded
by positive constants, the functional fails
to be differentiable on . Indeed, is only
derivable along directions of
so that the classical critical point theory cannot be
applied.
We will prove the existence of a critical point of by
assuming that there exist positive continuous functions
, and a positive constants
and satisfying , ,
, with in
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