1,720,961 research outputs found
Multiplicity of concentrating solutions for (p, q)-Schrödinger equations with lack of compactness
Full text linkWe study the multiplicity of concentrating solutions for the following class of (p, q)-Laplacian problems (Formula presented.) where ε > 0 is a small parameter, γ∈{0,1},1 infΛV for some bounded open set Λ ⊂ RN, and f: R → R is a continuous nonlinearity with subcritical growth. The main results are obtained by combining minimax theorems, penalization technique and Ljusternik–Schnirelmann category theory. We also provide a multiplicity result for a supercritical version of the above problem by combining a truncation argument with a Moser-type iteration. As far as we know, all these results are new
Fractional double-phase patterns: concentration and multiplicity of solutions
Full text linkWe consider the following class of fractional problems with unbalanced growth: {(−Δ)psu+(−Δ)qsu+V(εx)(|u|p−2u+|u|q−2u)=f(u)in RN,u∈Ws,p(RN)∩Ws,q(RN),u>0in RN, where ε>0 is a small parameter, s∈(0,1), [Formula presented], (−Δ)ts (with t∈{p,q}) is the fractional t-Laplacian operator, V:RN→R is a continuous potential satisfying local conditions, and f:R→R is a continuous nonlinearity with subcritical growth. Applying suitable variational and topological arguments, we obtain multiple positive solutions for ε>0 sufficiently small as well as related concentration properties, in relationship with the set where the potential V attains its minimum
Concentration of positive solutions for a class of fractional p-Kirchhoff type equations
Full text linkWe study the existence and concentration of positive solutions for the following class of fractional p-Kirchhoff type problems: 0 & where is a small positive parameter, a and b are positive constants, s (0, 1) and p (1, ∞) are such that, is the fractional p-Laplacian operator, f: → is a superlinear continuous function with subcritical growth and V: R3 → is a continuous potential having a local minimum. We also prove a multiplicity result and relate the number of positive solutions with the topology of the set where the potential V attains its minimum values. Finally, we obtain an existence result when f(u) = uq-1 + γur-1, where γ > 0 is sufficiently small, and the powers q and r satisfy 2p < q < ps≥ r. The main results are obtained by using some appropriate variational argument
Multiplicity results for constrained Neumann problems
No full textBy means of critical point theory on manifolds, we establish the existence of one, two or three solutions for a constrained Neumann problem driven by the p-Laplacian operator and depending on two real parameters. As a special application, we prove the existence of two nontrivial solutions for an unconstrained Neumann problem with positively homogeneous functions
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
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
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