2,160 research outputs found
Methods and tools to enjoy and to study inaccessible Heritage
Our research on a multi-purpose survey of cultural Heritage located in UNESCO Historical Centre of Naples has the following goals: to test some innovative strategies to improve public enjoyment for inaccessible sites; to explore the use of some interactive systems to study heritage in remote; to explore how to access the information system through AR applications. In this paper we are going to focus on comparison between interactive system to access 3D data and photogrammetric processing of panoramic images. We investigated on: a. the use of 360° panorama for 3D restitutions; b. the use of 360° panorama as an interface to 3D data to extract real 3D coordinates and accurately measure distances; c. the use of 3D PDF to access a 3D database
Second Order Phase Transitions : From Infinite to Finite Systems
We investigate the Equation of State (EOS) of classical systems having 300
and 512 particles confined in a box with periodic boundary conditions. We show
that such a system, independently on the number of particles investigated, has
a critical density of about 1/3 the ground state density and a critical
temperature of about . The mass distribution at the critical point
exhibits a power law with . Making use of the grand partition
function of Fisher's droplet model, we obtain an analytical EOS around the
critical point in good agreement with the one extracted from the numerical
simulations.Comment: RevTex file, 17 pages + 9 figures available upon request from
[email protected]
A model for liquid-striped liquid phase separation in liquids of anisotropic polarons
The phase separation between a striped polaron liquid at the particular
density and a high density polaron liquid is described by a modified Van der
Waals scheme. The striped polaron liquid represents the pseudo gap matter or
Wigner-like polaron phase at 1/8 doping in cuprate superconductors. The model
includes the tendency of pseudo- Jahn-Teller polarons to form anisotropic
directional bonds at a preferential volume with the formation of different
liquid phases. The model gives the coexistence of a first low density polaron
striped liquid and a second high density liquid that appears in cuprate
superconductors for doping larger than 1/8. We discuss how the strength of
anisotropic bonds controls the variation the phase separation scenarios for
complex systems in the presence of a quantum critical point where the phase
separation vanishes.Comment: 10 pages, 3 figure
Experimental Signals of Phase Transition
The connection between the thermodynamics of charged finite nuclear systems
and the asymptotically measured partitions is presented. Some open questions,
concerning in particular equilibrium partitions are discussed. We show a
detailed comparison of the decay patterns in Au+ C,Cu,Au central collisions and
in Au quasi-projectile events. Observation of abnormally large fluctuations in
carefully selected samples of data is reported as an indication of a first
order phase transition (negative heat capacity) in the nuclear equation of
state.Comment: 8 pages, 8th International Conference on Nucleus-Nucleus Collisions,
Moscow 200
Quantum wells, wires and dots with finite barrier: analytical expressions for the bound states
From a careful study of the transcendental equations fulfilled by the bound
state energies of a free particle in a quantum well, cylindrical wire or
spherical dot with finite potential barrier, we have derived analytical
expressions of these energies which reproduce impressively well the numerical
solutions of the corresponding transcendental equations for all confinement
sizes and potential barriers, without any adjustable parameter. These
expressions depend on a unique dimensionless parameter which contains the
barrier height and the sphere, wire or well radius.Comment: 4 pages, 3 figure
Photogrammetric processes and augmented reality applications using mobile devices
This contribution shows the first results of a research "in fieri", which aims to introduce low-cost instruments for the continuous monitoring of architectures. The use of these devices in the architectural field is of great interest to the scientific community and therefore, with the aim of researching rapid mapping methodologies, the integrated camera on the new iPhone 12PRO is analyzed and then compared with the NikonD5000 reflex camera, whose use is more consolidated. In the era of digitalization and industry 4.0, smartphones have made significant progress and these devices are establishing as ideal solutions, thanks to their technical characteristics, costs and portability, compared to other acquisition techniques. The study is aimed at experimenting with image-based methodologies with the use of low-cost sensors where the three-dimensional models will constitute the basic element on which, through augmented reality applications, it will be possible to implement strategies aimed at documentation, conservation and monitoring. The experiment, reported therein, was conducted on the facade of the Quadriportico of the Cathedral of San Matteo in Salerno, Italy
Guaranteed Non-Asymptotic Confidence Ellipsoids for FIR Systems
Recently, a new finite-sample system identification
algorithm, called Sign-Perturbed Sums (SPS), was introduced in [2]. SPS constructs finite-sample confidence regions that are centered around the least squares estimate, and are guaranteed to contain the true system parameters with a user-chosen exact probability for any finite number of data points. The main assumption of SPS is that the noise terms are independent and symmetrically distributed about zero, but they do not have to be stationary, nor do their variances and distributions have to be known. Although it is easy to determine if a particular parameter belongs to the confidence region, it is not easy to describe the boundary of the region, and hence to compactly represent the exact confidence region. In this paper we show that an ellipsoidal outer-approximation of the SPS confidence
region can be found by solving a convex optimization problem, and we illustrate the properties of the SPS region and the ellipsoidal outer-approximation in simulation examples
Scaling in the Lattice Gas Model
A good quality scaling of the cluster size distributions is obtained for the
Lattice Gas Model using the Fisher's ansatz for the scaling function. This
scaling identifies a pseudo-critical line in the phase diagram of the model
that spans the whole (subcritical to supercritical) density range. The
independent cluster hypothesis of the Fisher approach is shown to describe
correctly the thermodynamics of the lattice only far away from the critical
point.Comment: 4 pages, 3 figure
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