1,721,015 research outputs found
Punts d'equilibri globalment atractors
Get PDFUn punt d'equilibri d'un sistema dinàmic continu o discret és un atractor
global si l'òrbita de qualsevol punt tendeix a aquest punt d'equilibri quan el temps
tendeix a infinit. En aquest article tractem el problema de donar condicions suficients
perquè un punt d'equilibri d'un sistema dinàmic sigui un atractor global. En particular,
ens centrem en els problemes continu i discret de Markus-Yamabe i en les condicions
de LaSalle. Obtenim algunes respostes afirmatives a l'existència d'atractor global i
trobem diversos exemples que no la presenten. Al final explicitem un cas en què el
problema no està tancat. Els resultats que es presenten s'han obtingut en col.laboració
amb Armengol Gasull i Francesc Mañosas, i estan extrets dels articles comuns que se
citen a la bibliografia.An equilibrium point of a continuous or discrete dynamical system is a global
attractor if the orbit of any point tends to the equilibrium when time tends to
infinity. In this article we deal with the problem of giving sufficient conditions
for an equilibrium point of a dynamical system to be a global attractor. In
particular, we deal with continuous and discrete Markus-Yamabe problems and
Lasalle conditions. We obtain some affirmative answers to the existence of a
global attractor and we find some examples that do not exhibit it. Lastly, we
detail a case in which the problem is not solved. The presented results have
been obtained in collaboration with Armengol Gasull and Francesc Mañosas,
and have been taken from the common articles cited in the bibliography
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
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
Detection of special curves via the double resultant
Get PDFWe introduce several applications of the use of the double resultant through some examples of computation of different nature: special level sets of rational first integrals for rational discrete dynamical systems; remarkable values of rational first integrals of polynomial vector fields; bifurcation values in phase portraits of polynomial vector fields; and the different topologies of the offset of curves.The authors are partially supported by MINECO/ FEDER MTM2013-40998-P Grant. Johanna D. García-Saldaña is also partially supported by FONDECyT postdoctoral fellowship 3150131/2015. Armengol Gasull is also partially supported by Generalitat de Catalunya Grant 2014SGR568
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
Adaptación de un equipo de inertización de fangos a un apagador de óxido cálcico
No full textEl present treball, realitzat en col·laboració amb la empresa Sodimate Ibérica S.L. està basat en la transformació de un barrejador MBV 240, dissenyat per al tractament de fangs, en un apagador de calç viva.
El lector es trobarà dins del treball una breu explicació del que es la calç y de quins son els seus usos actuals, així com el nomenament d’alguns equips per als seus diferents tractaments, estratègies, adaptacions realitzades i anàlisis del entorn y competència, que s’han hagut de realitzar per a poder dur a terme el objectiu primordial.
Una gran part del temps dedicat a la realització d’aquest projecte es va destinar a aprendre les diferents particularitats de la calç, les seves aplicacions a la nostra societat i al equip de higienització de fangs. A continuació es modificarà per a poder utilitzar-lo com un apagador. Amb les modificacions fetes, es realitzaran unes proves experimentals per a comprovar la capacitat d’aquest equip per apagar òxid de calci. Veurem que no s’aconsegueixen les temperatures desitjades per a un òptim apagat de la calç, entre 70ºC i 80ºC, i es proposarà un nou disseny per a millorar els resultats obtinguts.
En resum, la adaptació del barrejador de fangs resulta molt interessant per a Sodimate, ja que li ofereix una oportunitat d’exportar a gran escala
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