131,620 research outputs found
Fridman function, injectivity radius function and squeezing function
No full textVery recently, the Fridman function of a complex manifold X has been identified as a dual of the squeezing function of X. In this paper, we prove that the Fridman function for certain hyperbolic complex manifold X is bounded above by the injectivity radius function of X. This result also suggests us to use the Fridman function to extend the definition of uniform thickness to higher dimensional hyperbolic complex manifolds. We also establish an expression for the Fridman function (with respect to the Kobayashi metric) when X = D/Γ and Γ is a torsion-free discrete subgroup of isometries on the standard open unit disk D. Hence explicit formulae of the Fridman functions for the annulus A_r and the punctured disk D∗ are derived. These are the first explicit non-constant Fridman functions. Finally, we explore the boundary behavior of the Fridman functions (with respect to the Kobayashi metric) and the squeezing functions for regular type hyperbolic Riemann surfaces and planar domains, respectively.published_or_final_versio
Squeezing function, Fridman function and proper maps on multiply connected domains
No full textLet be a bounded domain in . To study the geometric properties of , one may introduce on the \textit{squeezing function} and the \textit{Fridman function} (where or refers to the Kobayashi metric or Carath\'{e}dory metric respectively). These two functions are biholomorphic invariants of , i.e., and for any biholomorphism . They are useful for estimating some of intrinsic metrics of as well as proving pseudoconvexity of . Some estimates of these functions near the boundary of are known. However, very few explicit and are known. In Chapter 3, we will prove the explicit form for the squeezing function when is an annulus and hence determine the explicit form for the squeezing function of all non-degenerated bounded doubly connected planar domains up to biholomorphisms. This serves as the first non-trivial formula of squeezing functions for planar domains except and as well as their biholomorphic analogue. This also answers a question asked by E.F. Wold in 2017 about the precise form for . The main tools applied in Chapter 3 are explicit formulae of conformal maps from annuli to circularly slit disk in terms of the Schottky-Klein prime functions (introduced in Chapter 2) and slit map approximations using Loewner-type differential equation introduced in Chapter 3. This is a joint work of the candidate with Prof. Tuen-Wai Ng and Dr. Jonathan Tsai.
Squeezing functions were introduced by F. Deng, Q. Guan and L. Zhang in 2012, and it is currently an active research area in several complex variables and complex geometry. On the other hand, the Fridman function has only been recently identified as a dual of the squeezing function by Mahajan and Verma in 2019. In line with the explicit form of the squeezing function we found in Chapter 3, we will also explore in Chapter 4 the explicit form for the Fridman function on some complex manifold . We will prove that the Fridman function over a class of -hyperbolic complex manifolds is bounded above by the injectivity radius function (introduced in Chapter 4) for . This result also suggests us to use the Fridman function to extend the definition of uniform thickness to higher-dimensional -hyperbolic complex manifolds. We will also find an explicit formula for when where or equivalently and is a torsion-free discrete group of isometries of . In particular, explicit formulae for and will be given in Chapter \ref{Ch:fri}, for comparison with the explicit form for .
Our proofs in Chapter 3 and 4 involve finding the extremal functions for some optimization problems. Often, the extremal functions of the optimization problems considered in function theory are proper holomorphic maps. This simulates us to study formulae of proper holomorphic maps from multiply connected circular domains in onto the standard unit disk . The explicit form of proper holomorphic maps from annulus onto has only been recently obtained by Wang and Yin in 2017, and independently, by Bogatyrev in 2019. In Chapter 5, we will establish the explicit form of proper holomorphic maps from the multiply connected circular domain onto the unit disk using again the Schottky-Klein prime functions. This answers a question of Schmieder in 2005, which is about constructing proper holomorhpic mappings of degree from multiply connected domains to the unit disk .published_or_final_versionMathematicsDoctoralDoctor of Philosoph
La educación física en la escuela y su enseñanza : homogeneidades, diversidades y particularidades
No full textTabla de contenidos: Introducción. Qué enseña cuando enseña / Osvaldo O. Ron, Jorge L. Fridman, Ezequiel Camblor. Experiencias y construcción de saberes / Adriana I. Apphesberho, Jonatan D. Barrientos Maciel, Carola Inchaurregui. Saber y oficio en la enseñanza de la educación física escolar / José A. Fotia. El juego de jugar en la escuela / Guillermo Celentano. El deporte en la escuela. Una primera mirada sobre su enseñanza desde la perspectiva de los profesores y las profesoras / Fabián A. De Marziani. Enseñar con anclaje deportivo / Mirian Burga. La gimnasia en la escuela. Sentidos y significados de esta práctica en la actualidad / Marcelo A. Husson. Qué se dice que enseña la educación física en el nivel secundario. Entre los documentos curriculares y las narrativas de los profesores y las profesoras / Pablo Kopelovich, Alejo Levoratti. Alumnas y alumnos: experiencias en torno al deporte y a las prácticas en educación física / Marco Maiori, Daniel Zambaglione. Educación física escolar: vínculos, actores y voces / Lorena Irene Berdula. Palabras Finales. Homogeneidades, diversidades y particularidades en la enseñanza de la educación física escolar. Productos que las tradiciones no nos dejan ver / Osvaldo O. Ron, Jorge L. Fridman
La educación física en la escuela y su enseñanza : homogeneidades, diversidades y particularidades
No full textTabla de contenidos: Introducción. Qué enseña cuando enseña / Osvaldo O. Ron, Jorge L. Fridman, Ezequiel Camblor. Experiencias y construcción de saberes / Adriana I. Apphesberho, Jonatan D. Barrientos Maciel, Carola Inchaurregui. Saber y oficio en la enseñanza de la educación física escolar / José A. Fotia. El juego de jugar en la escuela / Guillermo Celentano. El deporte en la escuela. Una primera mirada sobre su enseñanza desde la perspectiva de los profesores y las profesoras / Fabián A. De Marziani. Enseñar con anclaje deportivo / Mirian Burga. La gimnasia en la escuela. Sentidos y significados de esta práctica en la actualidad / Marcelo A. Husson. Qué se dice que enseña la educación física en el nivel secundario. Entre los documentos curriculares y las narrativas de los profesores y las profesoras / Pablo Kopelovich, Alejo Levoratti. Alumnas y alumnos: experiencias en torno al deporte y a las prácticas en educación física / Marco Maiori, Daniel Zambaglione. Educación física escolar: vínculos, actores y voces / Lorena Irene Berdula. Palabras Finales. Homogeneidades, diversidades y particularidades en la enseñanza de la educación física escolar. Productos que las tradiciones no nos dejan ver / Osvaldo O. Ron, Jorge L. Fridman
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
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