39 research outputs found
Mathematical Analysis and Computational Integration of Massive Heterogeneous Data from the Human Retina
Modern epidemiology integrates knowledge from heterogeneous collections of
data consisting of numerical, descriptive and imaging. Large-scale
epidemiological studies use sophisticated statistical analysis, mathematical
models using differential equations and versatile analytic tools that handle
numerical data. In contrast, knowledge extraction from images and descriptive
information in the form of text and diagrams remain a challenge for most
fields, in particular, for diseases of the eye. In this article we provide a
roadmap towards extraction of knowledge from text and images with focus on
forthcoming applications to epidemiological investigation of retinal diseases,
especially from existing massive heterogeneous collections of data distributed
around the globe.Comment: 9 pages, 3 figures, submitted and accepted in Damor2012 conference:
http://www.uninova.pt/damor2012/index.php?page=author
Next generation computer algebra systems AXIOM and the scratchpad concept: applications to research in algebra
One way in which mathematicians deal with infinite amounts of data is symbolic representation. A simple example is the quadratic equation x = âb±âb2â4ac 2a, a formula which uses symbolic representation to describe the solutions to an infinite class of equations. Most computer algebra systems can deal with polynomials with symbolic coefficients, but what if symbolic exponents are called for (e.g., 1+t i)? What if symbolic limits on summations are also called for (e.g., 1+t+...+t i = ïżœ j tj)? The âScratchpad Concept â is a theoretical ideal which allows the implementation of objects at this level of abstraction and beyond in a mathematically consistent way. The AXIOM computer algebra system is an implementation of a major part of the Scratchpad Concept. AXIOM (formerly called Scratchpad) is a language with extensible parameterized types and generic operators which is based on the notions of domains and categories [Lambe1], [Jenks-Sutor]. By examining some aspects of the AXIOM system, the Scratchpad Concept will be illustrated. It will be shown how some complex problems in homological algebra were solved through the use of this system. New paradigms are evolving in computer science. There is a thrust towards type
On the Quantum Yang-Baxter Equation with Spectral Parameter, I
In memory of Grace Lambe The quantum YangâBaxter equation (QYBE) is related to the study of integrabl
Resolutions via homological perturbation
The purpose of this paper is to review an algorithm for computing âsmall â resolutions in homological algebra, to provide examples of its use as promised in [L1], [LS], and to illustrate the use of computer algebra in an area not usually associated with that subject. Comparison of the complexes produced by the method discussed here with those produced by other methods show
Resolutions which split off of the bar construction
AbstractResolutions which split off of the bar construction are quite common, but explicit formulae expressing these splittings are not often encountered. Given explicit splitting data, perturbations of resolutions can be computed and the perturbed resolutions can be used tomake complete effective calculations where previously only partial or indirect results were obtainable.This paper gives a foundation for the perturbation method in homological algebra by providing a symbolic encoding of binomial coefficient functions which is useful in deriving formulae for an infinite class of resolutions. Formulae for perturbations of those resolutions are then derived. Applications to certain infinite families of groups and monoids are given.The research for this theory as well as the calculation of closed formulae within the theory was aided by new methods in symbolic computation using the Axiom (formerly called Scratchpad) system
DEGREES OF MAPPINGS OF MANIFOLDS.
DEGREES OF MAPPINGS OF MANIFOLDS
The cohomology ring of the free loop space of a wedge of spheres and cyclic homology
Abstract â We investigate the cohomology of the free loop space of a one point union of a three-sphere with itself. The even dimensional subalgebra is not free and relations are presented explicitly. This algebra may also be identified as the cyclic homology of a ânull algebraâ. Lâanneau de cohomologie de lâespace de lacets libres dâun bouquet de sphĂšres et lâhomologie cyclique. RĂ©sumĂ© â Nous Ă©tudions lâalgĂšbre de cohomologie de lâespace de lacets libres de lâespace obtenu en identifiant deux spheres S 3 en un point. La sous-algĂšbre (commutative) formĂ©e des Ă©lĂ©ments de degrĂ© pair nâest pas libre et nous en donnons des relations explicites. Cette algĂšbre peut aussi ĂȘtre identifiĂ©e Ă lâhomologie cyclique dâune certaine algĂšbre Ă multiplication nulle. Version française abrĂ©gĂ©e â Nous Ă©tudions lâanneau de cohomologie Ă coefficients rationnels de lâespace L(X) de lacets libres sur X = S 3 âšS 3. Dans ce cas la suite spectrale dâEilenberg-Moore dĂ©gĂ©nĂšre et nous obtenons H â (L(X)) ⌠= Tor H â (X) e (H â (X), H â (X)). La sous-algĂšbre K de H â (L(X)) formĂ©e des Ă©lĂ©ments de degrĂ© pair dĂ©termine H â (L(X)) et de plus K peut ĂȘtre identifiĂ©e (modulo une translation des degrĂ©s) Ă lâhomologie cyclique dâune algĂšbre a multiplication triviale ([4], [5], [6]). La sĂ©rie gĂ©nĂ©ratrice de K est Ă©gale a ([3], [4], [9]): α(t) = 1 â ïżœ iâ„1 Ï(i) i log(1 â 2t 2i) oĂč Ï est la fonction dâEuler. On montre lâexistence de relations dans K en Ă©crivant cette sĂ©rie comme un produit infini i=