1,721,052 research outputs found
Upper Bounds for the Blow Up Time for the Kirchhoff-Type Equation
No full textPiskin, Erhan/0000-0001-6587-4479; Dinc, Yavuz/0000-0003-0897-4101; Tunc, Cemil/0000-0003-2909-8753. In this research, we take into account the Kirchhoff type equation with variable exponent. The Kirchhoff type equation is known as a kind of evolution equations,namely, PDEs, where t is an independent variable. This type problem can be extensively used in many mathematical models of various applied sciences such as flows of electrorheological fluids, thin liquid films, and so on. This research, we investigate the upper bound for blow up time under suitable conditions
Sobre la inestabilidad de ecuaciones diferenciales funcionales no lineales de orden cinco
No full textThe author gives sufficient conditions for non-existence of periodic solutions of two higher order nonlinear delay differential systems. Our technical approach is based on the construction of two suitable Lyapunov type functionals. An example is given to illustrate the obtained results. The main results here improve recent results found on the topic in the literature from the case of without delay to the delay case.El autor presenta condiciones suficientes para la existencia de soluciones periódicas de dos ecuaciones diferenciales con retraso de alto orden. El enfoque técnico se fundamenta en la construcción de funcionales de Lyapunov adecuados. Un ejemplo ilustra los resultados obtenidos. El resultado principal presentado en este artículo mejora un resultado reciente en el tema de pasar el caso sin atraso al caso con atraso
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
On the instability of solutions of nonlinear delay differential equations of fourth and fifth order
No full textThe main purpose of this paper is to introduce some new instability theorems related to certain fourth and fifth order nonlinear differential equations with a constant delay. By means of the Lyapunov-Krasovskii functional approach, we obtained two new results on the topic
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
New results on the stability and boundedness of nonlinear differential equations of fifth order with multiple deviating arguments
No full textWe address differential equations of fifth order with multiple deviating arguments and investigate the stability and boundedness of solutions of the equation considered by functional Liapunov approach
Asymptotic stability of solutions of a class of neutral differential equations with multiple deviating arguments
No full textIn this paper, using the Lyapunov-Krasovskii functional approach, some novel stability criteria are presented for all solutions of a class of nonlinear neutral differential equations to tend zero when t -> infinity
On the Instability of Solutions of Nonlinear Delay Differential Equations of Fourth and Fifth Order
No full textThe main purpose of this paper is to introduce some new instability theorems related to certain fourth and fifth order nonlinear differential equations with a constant delay. By means of the Lyapunov-Krasovskii functional approach, we obtained two new results on the topic
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