5,398 research outputs found
Functional implications of minor mandibular asymmetry: clinical and digital research on a sample of healthy patients
OBJECTIVE.The aim of the study is to evaluate the influence that the mandibular asymmetry could have towards the other components of the Stomathognatic system and to further related structures from a functional point of view. MATERIALS and METHODS. A sample of 18 young asymmetric patients, in healthy status, was investigated with clinical evaluation and questionnaires and digital devices such as Electromiography, Stabilometry, T-scan and Formetric. Descriptive and quantitative statistical analysis were performed. RESULTS. ASIM electromyography index was significant only in a short percentage of the sample. Hypertonia of temporalis muscle in the same side of mandibular deviation and the cross-activation of the contralateral masseter were present. The data of the stabilometric platform showed that only 33% of patients had a load discrepancy between right and left side. All patients presented similar and limited postural anomalies during the Formetric examination. No significant results emerged from statistics . CONCLUSIONS. From the emerging data, mandibular asymmetry does not seem to be considered a potential risk factor for the development of functional anomalies both in the stomatognatic system and in the postural one. The only issue that should be considered is the condylar retrusion of the mandibular shortest side that is a possible destabilizing factor of the TMJ condyle-disc coordination
Functional implications of minor mandibular asymmetry: clinical and digital research on a sample of healthy patients
OBJECTIVE.The aim of the study is to evaluate the influence that the mandibular asymmetry could have towards the other components of the Stomathognatic system and to further related structures from a functional point of view. MATERIALS and METHODS. A sample of 18 young asymmetric patients, in healthy status, was investigated with clinical evaluation and questionnaires and digital devices such as Electromiography, Stabilometry, T-scan and Formetric. Descriptive and quantitative statistical analysis were performed. RESULTS. ASIM electromyography index was significant only in a short percentage of the sample. Hypertonia of temporalis muscle in the same side of mandibular deviation and the cross-activation of the contralateral masseter were present. The data of the stabilometric platform showed that only 33% of patients had a load discrepancy between right and left side. All patients presented similar and limited postural anomalies during the Formetric examination. No significant results emerged from statistics . CONCLUSIONS. From the emerging data, mandibular asymmetry does not seem to be considered a potential risk factor for the development of functional anomalies both in the stomatognatic system and in the postural one. The only issue that should be considered is the condylar retrusion of the mandibular shortest side that is a possible destabilizing factor of the TMJ condyle-disc coordination
A Vertical Resonance Heating Model for X- or Peanut-Shaped Galactic Bulges
We explore a second order Hamiltonian vertical resonance model for X-shaped
or peanut-shaped galactic bulges. The X-shape is caused by the 2:1 vertical
Lindblad resonance with the bar, with two vertical oscillation periods per
orbital period in the bar frame. We examine N-body simulations and find that
due to the bar slowing down and disk thickening during bar buckling, the
resonance and associated peanut-shape moves outward. The peanut-shape is
consistent with the location of the vertical resonance, independent of whether
the bar buckled or not. We estimate the resonance width from the potential m=4
Fourier component and find that the resonance is narrow, affecting orbits over
a narrow range in the angular momentum distribution, dL/L ~ 0.05. As the
resonance moves outward, stars originally in the mid plane are forced out of
the mid plane into orbits just within the resonance separatrix. The height of
the separatrix orbits, estimated from the Hamiltonian model, is approximately
consistent with the peanut-shape height. The X-shape is comprised of stars in
the vicinity of the resonance separatrix. The velocity distributions from the
simulations illustrate that low inclination orbits are depleted within
resonance. Within resonance, the vertical velocity distribution is broad,
consistent with resonant heating caused by the passage of the resonance through
the disk. In the Milky Way bulge we relate the azimuthally averaged mid-plane
mass density near the vertical resonance to the rotation curve and bar pattern
speed. At an estimated vertical resonance galactocentric radius of ~1.3 kpc, we
confirm a mid-plane density of ~5x10^8 Msol/kpc^3, consistent with recently
estimated mass distributions. We find that the rotation curve, bar pattern
speed, 2:1 vertical resonance location, X-shape tips, and mid-plane mass
density, are all self-consistent in the Milky Way galaxy bulge.Comment: accepted for publication in MNRA
Modeling the melting of multicomponent systems: the case of MgSiO3 perovskite under lower mantle conditions
Knowledge of the melting properties of materials, especially at extreme pressure conditions, represents a long-standing scientific challenge. For instance, there is currently considerable uncertainty over the melting temperatures of the high-pressure mantle mineral, bridgmanite (MgSiO3-perovskite), with current estimates of the melting T at the base of the mantle ranging from 4800 K to 8000 K. The difficulty with experimentally measuring high pressure melting temperatures has motivated the use of ab initio methods, however, melting is a complex multi-scale phenomenon and the timescale for melting can be prohibitively long. Here we show that a combination of empirical and ab-initio molecular dynamics calculations can be used to successfully predict the melting point of multicomponent systems, such as MgSiO3 perovskite. We predict the correct low-pressure melting T, and at high-pressure we show that the melting temperature is only 5000 K at 120 GPa, a value lower than nearly all previous estimates. In addition, we believe that this strategy is of general applicability and therefore suitable for any system under physical conditions where simpler models fail
LA SCUOLA OFFICINA MECCANICA PRESSO IL VILLAGGIO MONTE DEGLI ULIVI A RIESI. RICOSTRUZIONE DI UN PROCESSO TRA ANALISI COMPOSITIVE E GRAFICO-GEOMETRICHE
Il presente contributo trae origine da una pi\uf9 ampia ricerca che ha consentito di approfondire
la comprensione dei principi progettuali e geometrico-compositivi dell\u2019opera in oggetto; avvalendosi
anche di un rilievo scientifico integrato che, attraverso nuove tecniche digitali applicate,
ha permesso di condurre una specifica analisi grafico-geometrica sull\u2019impianto
architettonico1.
L\u2019edificio della scuola officina meccanica, inserito in un pi\uf9 ampio e articolato complesso edilizio2,
\ue8 composto da una singolare configurazione in pianta ai diversi livelli, oggi non pi\uf9
chiaramente leggibile a causa dei numerosi interventi di trasformazione subiti. I disegni di restituzione
grafica, realizzati sulla base dei rilievi architettonici, costituiscono un imprescindibile
documento di consultazione che documenta l\u2019attuale distribuzione dei locali che hanno alterato
l\u2019idea progettuale. Con l\u2019intento di acquisire nuovi elementi di conoscenza propedeutici a futuri
interventi di restauro conservativo e a una pi\uf9 consapevole fruizione del bene, lo studio descrive
ed esamina il processo progettuale dell\u2019opera, ricercando i principi ordinatori, compositivi e
geometrici che ne hanno determinato la particolare struttura.
Il testo \ue8 articolato in due parti: la prima sintetizza le questioni generali del progetto, dalla
ideazione alla realizzazione del Villaggio Monte degli Ulivi e dell\u2019edificio della ex scuola officina
meccanica; la seconda, sulla scorta dei risultati di uno studio sulle funzioni grafiche digitali
applicate alla geometria, indaga la natura geometrica dei profili conici che regolano il progetto
e la realizzazione dell\u2019edificio.This contribution originates from a wider research which allowed to analyse in depth both the design and geometric-compositional principles of the Scuola Officina Meccanica's building - located within the wide and structured building complex in Villaggio \u201cMonte degli Ulivi\u201d. A scientific integrated survey was also used that, thanks to newly-applied digital techniques, allowed to carry out a specific graphic-geometric analysis of the architectural layout. The study is developed in two parts. The first summarizes the general matters of the project, from the design to the realisation of both Villaggio \u201cMonte degli Ulivi\u201d and the building of the former Scuola Officina Meccanica. The second part, on the basis of the results from digital graphic functions applied to the geometry, investigates the geometric nature of the conic profiles regulating both the project and the realisation of the building
IMAGE-BASED MODELING TECHNIQUES FOR ARCHITECTURAL HERITAGE 3D DIGITALIZATION: LIMITS AND POTENTIALITIES
3D reconstruction from images has undergone a revolution in the last few years. Computer vision techniques use photographs from data set collection to rapidly build detailed 3D models. The simultaneous applications of different algorithms (MVS), the different techniques of image matching, feature extracting and mesh optimization are inside an active field of research in computer vision. The results are promising: the obtained models are beginning to challenge the precision of laser-based reconstructions. Among all the possibilities we can mainly distinguish desktop and web-based packages. Those last ones offer the opportunity to exploit the power of cloud computing in order to carry out a semi-automatic data processing, thus allowing the user to fulfill other tasks on its computer; whereas desktop systems employ too much processing time and hard heavy approaches. Computer vision researchers have explored many applications to verify the visual accuracy of 3D model but the approaches to verify metric accuracy are few and no one is on Autodesk 123D Catch applied on Architectural Heritage Documentation. Our approach to this challenging problem is to compare the 3Dmodels by Autodesk 123D Catch and 3D models by terrestrial LIDAR considering different object size, from the detail (capitals, moldings, bases) to large scale buildings for practitioner purpose
Reconstructing urban scene 3D using VisualSfM
New computer vision techniques use photo dataset
to rapidly build detailed 3D models. Computer-
vision researchers have explored many approaches
to city-scale 3D reconstruc on. Among
these systems stands out VisualSfM developed by
the University of Washington & Google Inc. It is a
open source GUI applica on of a Structure from
Mo on (SfM) so! ware that uses a feature extractor
called Si! GPU and the Mul core Bundle
Adjustment. In addi on it embeds the CMVS/
PMVS2 able to reconstruct dense 3D point cloud.
Our goal is to demonstrate the metric accuracy of
VisualSfM+CMVS/PMVS2 and that to get run it,
you can use an unstructured photo dataset but
the result improves if you use a structured photo
dataset. The approach has been tested on several
large datasets with structured images
K-means Clustering to Study How Student Reasoning Lines Can Be Modified by a Learning Activity Based on Feynman\u2019s Unifying Approach
Research in Science Education has shown that often students need to learn how to identify differences and similarities between descriptive and explicative models.
The development and use of explicative skills in the field of thermal science has always been a difficult objective to reach. A way to develop analogical reasoning is to use in Science Education unifying conceptual frameworks.
In this paper we describe a 20-hour workshop focused on Feynman\u2019s Unifying Approach and the two-level system. We measure its efficacy in helping undergraduate chemical engineering students explain phenomena by applying an explanatory model. Contexts involve systems for which a process is activated by thermally overcoming a well-defined potential barrier. A questionnaire containing six open-ended questions was administered to the students before instruction. A second one, similar but focused on different physical content was administered after instruction. Responses were analysed using k-means Cluster Analysis and students\u2019 inferred lines of reasoning about the analysed phenomena were studied. We conclude that students reasoning lines seem to have clearly evolved to explicative ones and it is reasonable to think that the Feynman Unifying Approach has favoured this change
Prospective elementary teachers\u2019 perceptions of the processes of modeling: A case study
In this paper we discuss a study on the approaches to modeling of students of the 4-year elementary school teacher program at the University of Palermo, Italy. The answers to a specially designed questionnaire are analyzed on the basis of an a priori analysis made using a general scheme of reference on the epistemology of mathematics and physics. The study is performed by using quantitative data analysis methods, i.e. factorial analysis of the correspondences and implicative analysis. A qualitative analysis of key words and terms used by students during interviews is also used to examine some aspects that emerged from the quantitative analysis. The students have been classified on the basis of their different epistemological approaches to knowledge construction, and implications between different conceptual strategies used to answer the questionnaire have been highlighted. The study\u2019s conclusions are consistent with previous research, but the use of quantitative data analysis allowed us to classify the students into three \u201cprofiles\u201d related to different epistemological approaches to knowledge construction, and to show the implications of the different conceptual strategies used to answer the questionnaire, giving an estimation of the classification or implication \u201cstrength.\u201d Some hints on how a course for elementary school physics and mathematics education can be planned to orient the future teachers to the construction of models of explanation are reported
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