14,770 research outputs found
Leibniz's Principles and Topological Extensions
Three philosophical principles are often quoted in connection with Leibniz:
"objects sharing the same properties are the same object", "everything can
possibly exist, unless it yields contradiction", "the ideal elements correctly
determine the real things". Here we give a precise formulation of these
principles within the framework of the Topological Extensions of [8],
structures that generalize at once compactifications, completions, and
nonstandard extensions. In this topological context, the above Leibniz's
principles appear as a property of separation, a property of compactness, and a
property of analyticity, respectively. Abiding by this interpretation, we
obtain the somehow surprising conclusion that these Leibnz's principles can be
fulfilled in pairs, but not all three together.Comment: 16 page
A topological interpretation of three Leibnizian principles within the functional extensions
Three philosophical principles are often quoted in connection with Leibniz:
"objects sharing the same properties are the same object" (Identity of
indiscernibles), "everything can possibly exist, unless it yields
contradiction" (Possibility as consistency), and "the ideal elements correctly
determine the real things" (Transfer). Here we give a precise
logico-mathematical formulation of these principles within the framework of the
Functional Extensions, mathematical structures that generalize at once
compactifications, completions, and elementary extensions of models. In this
context, the above Leibnizian principles appear as topological or algebraic
properties, namely: a property of separation, a property of compactness, and a
property of directeness, respectively. Abiding by this interpretation, we
obtain the somehow surprising conclusion that these Leibnizian principles may
be fulfilled in pairs, but not all three together.Comment: arXiv admin note: substantial text overlap with arXiv:1012.434
CKM Parameters and Rare B Decays
Measurements of the angles and sides of the unitarity triangle and of the
rates of rare B meson decays are crucial for the precise determination of
Standard Model parameters and are sensitive to the presence of new physics
particles in the loop diagrams. In this paper the recent measurements performed
in this area by Babar and Belle will be presented. The direct measurement of
the angle alpha is for the first time as precise as the indirect determination.
The precision of the V_ub determination has improved significantly with respect
to previous measurement. New limits on B->tau nu decays are presented, as well
as updated measurements on b->s radiative transitions and a new observation of
b->d gamma transition made by Belle.Comment: Talk presented at the Lepton-Photon 2005 Symposium, June 30-July 5,
Uppsala, Sweden. 14 pages, 13 figure
The XII century towers, a benchmark of the Rome countryside almost cancelled. The safeguard plan by low cost uav and terrestrial DSM photogrammetry surveying and 3D Web GIS applications
“Giving a bird-fly look at the Rome countryside, throughout the Middle Age central period, it would show as if the multiple city
towers has been widely spread around the territory” on a radial range of maximum thirty kilometers far from the Capitol Hill center
(Carocci and Vendittelli, 2004).
This is the consequence of the phenomenon identified with the “Incasalamento” neologism, described in depth in the following
paper, intended as the general process of expansion of the urban society interests outside the downtown limits, started from the half
of the XII and developed through all the XIII century, slowing down and ending in the following years. From the XIX century till
today the architectural finds of this reality have raised the interest of many national and international scientists, which aimed to study
and catalog them all to create a complete framework that, cause of its extension, didn’t allow yet attempting any element by element
detailed analysis. From the described situation has started our plan of intervention, we will apply integrated survey methods and
technologies of terrestrial and UAV near stereo-photogrammetry, by the use of low cost drones, more than action cameras and reflex
on extensible rods, integrated and referenced with GPS and topographic survey. In the final project we intend to produce some 3D
scaled and textured surface models of any artifact (almost two hundreds were firstly observed still standing), to singularly study the
dimensions and structure, to analyze the building materials and details and to formulate an hypothesis about any function, based even
on the position along the territory. These models, successively georeferenced, will be imported into a 2D and 3D WebGIS and
organized in layers made visible on basemaps of reference, as much as on historical maps
Secure Cloud-Edge Deployments, with Trust
Assessing the security level of IoT applications to be deployed to
heterogeneous Cloud-Edge infrastructures operated by different providers is a
non-trivial task. In this article, we present a methodology that permits to
express security requirements for IoT applications, as well as infrastructure
security capabilities, in a simple and declarative manner, and to automatically
obtain an explainable assessment of the security level of the possible
application deployments. The methodology also considers the impact of trust
relations among different stakeholders using or managing Cloud-Edge
infrastructures. A lifelike example is used to showcase the prototyped
implementation of the methodology
Statistical properties of time-reversible triangular maps of the square
Time reversal symmetric triangular maps of the unit square are introduced
with the property that the time evolution of one of their two variables is
determined by a piecewise expanding map of the unit interval. We study their
statistical properties and establish the conditions under which their
equilibrium measures have a product structure, i.e. factorises in a symmetric
form. When these conditions are not verified, the equilibrium measure does not
have a product form and therefore provides additional information on the
statistical properties of theses maps. This is the case of anti-symmetric cusp
maps, which have an intermittent fixed point and yet have uniform invariant
measures on the unit interval. We construct the invariant density of the
corresponding two-dimensional triangular map and prove that it exhibits a
singularity at the intermittent fixed point.Comment: 15 pages, 3 figure
Quasi-selective ultrafilters and asymptotic numerosities
We isolate a new class of ultrafilters on N, called "quasi-selective" because
they are intermediate between selective ultrafilters and P-points. (Under the
Continuum Hypothesis these three classes are distinct.) The existence of
quasi-selective ultrafilters is equivalent to the existence of "asymptotic
numerosities" for all sets of tuples of natural numbers. Such numerosities are
hypernatural numbers that generalize finite cardinalities to countable point
sets. Most notably, they maintain the structure of ordered semiring, and, in a
precise sense, they allow for a natural extension of asymptotic density to all
sequences of tuples of natural numbers.Comment: 27 page
The ribbed drapery of the Puerto Princesa Underground River (Palawan, Philippines): morphology and genesis
During the 2011 speleological expedition to the Puerto Princesa Underground River (Palawan, Philippines) a drapery characterized by several close-to-horizontal ribs has been noticed. Even without sampling and analyzing its internal growth layers, a detailed morphological study allowed to present a possible genetic model. The presented model helps to explain its evolution, which is mainly controlled by variation in water flow as a consequence of the Palawan climate. When validated by further analyses, the same genetic mechanism could define also the evolution of the very common but still unexplained complex flowstones, which exhibit several close-to-horizontal steps, widenings and narrowings along their growth axis
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