A binary representation of the rationals derived from their continued fraction expansions is described and analysed. The concepts \adjacency", \mediant" and \convergent" from the literature on Farey fractions and continued fractions are suitably extended to provide a foundation for this new binary representation system. Worst case representation-induced precision loss for any real number by a x...

in addition to exploring constructions and properties of limits and colimits in categories of topologicalalgebras, we study special subcategories of topological algebras and their properties. in particular, undercertain conditions, reflective subcategories when paired with topological structures give rise to reflectivesubcategories and epireflective subcategories give rise to epireflective subc...

these are notes from introductory survey lectures given at the institute for studies in theoretical physics and mathematics (ipm), teheran, in 2008 and 2010. we present the definition and the fundamental properties of fomin-zelevinsky’s cluster algebras. then, we introduce quiver representations and show how they can be used to construct cluster variables, which are the canonical generators of ...

rosa damascena has been found to act on central nervous system including the brain. several studies confirm that r. damascena inhibits the activity of the hypothalamus and pituitary systems in rat and can suppress the central nervous system. in traditional medicine hypnotic effect of rose is also suggested. in this study, the hypnotic effect of the ethanol crude extract of r. damascena and its ...

1.1. Summary. This paper is essentially a continuation of [3], where we introduced a (standard) simplicial localization functor, which assigned to every category C and subcategory W c C, a simpficiaf category LC with in each dimension the same objects as C (i.e. for every two objects X, YE C, the maps X -+ YE LC form a simplicial set LC(X, Y)). This simplicial localization has all kinds of nice...

This paper provides an abstract definition of some kinds of logics, called diagrammatic logics, together with a definition of morphisms and of 2-morphisms between diagrammatic logics. The definition of the 2-category of diagrammatic logics rely on category theory, mainly on adjunction, categories of fractions and limit sketches. This framework is applied to the formalization of a parameterizati...

abstract a study was conducted to evaluate the effect of incubation time, sewage sludge and clay content on the distribution of nickel and cadmium in different fractions of selected calcareous soils. to meet this purpose, an experiment with two different soils (4 and 30 percent caco3), two different textures (8 and 40 percent clay), two levels of nickel (0 and 100 mg.kg-1), two levels of cadmiu...