2,218 research outputs found
Functional Approach to Classical Yang-Mills Theories
Sometime ago it was shown that the operatorial approach to classical
mechanics, pioneered in the 30's by Koopman and von Neumann, can have a
functional version. In this talk we will extend this functional approach to the
case of classical field theories and in particular to the Yang-Mills ones. We
shall show that the issues of gauge-fixing and Faddeev-Popov determinant arise
also in this classical formalism.Comment: 4 pages, Contribution to the Proceedings of the International Meeting
"Quantum Gravity and Spectral Geometry" (Naples, July 2-7, 2001
A decision support system based on Electre III for safety analysis in a suburban road network
The aim of this paper is to develop a method for supporting decision makers in transport planning. When funds are insufficient to cover the interventions required to ensure safe driving conditions, it is necessary to optimize resources for the most critical sections. In this analysis, the multicriteria ranking method based on the ELECTRE III algorithms is applied to a real case, involving different sections of a motorway. This analysis is based on a comparison of different road sections in regard to safety conditions. The rank of more critical sections identifies intervention priorities
A decision support system for road safety analysis
The aim of this paper is to develop a procedure for supporting public administrations in planning safety interventions on the road network. Road safety conditions depend on several factors, represented by a variety of quantitative and qualitative data, including: number of traffic accidents, traffic flow, lane width, shoulder width, road curvature and grade, access-point density, road markings and road signs (Mooren et al., 2012; OECD, 2002). By analysing a set of given roads or different sections of the same road, each with specific safety conditions, this methodology allows to determine which sections require interventions to improve safe driving conditions. Specifically, the multicriteria analysis technique is used in decision-making processes to support the choice among different alternatives in complex problems (Fadda, 2002). Among the different multicriteria techniques available, the Concordance Analysis will be used here. This paper proposes a unique modelling tool that incorporates the different indicators to calculate safety conditions. The methodology has been applied to a real case study for evaluating road safety on sections of a motorway infrastructur
Conformal Dynamics of 0-Branes
We investigate the dynamics of dilatonic D-dimensional 0-branes in the
near-horizon regime. The theory is given in a twofold form: two-dimensional
dilaton gravity and nonlinear sigma model. Using asymptotic symmetries, duality
relations, and sigma model techniques we find that the theory has three
conformal points which correspond to (a) the asymptotic (Anti-de Sitter) region
of the two-dimensional spacetime, (b) the horizon of the black hole, and (c)
the infinite limit of the coupling parameter. We show that the conformal
symmetry is perturbatively preserved at one-loop, identify the corresponding
conformal field theories, and calculate the associated central charges.
Finally, we use the conformal field theories to explain the thermodynamical
properties of the two-dimensional black holes.Comment: 22 pages, LaTex fil
Chiral Anomalies via Classical and Quantum Functional Methods
In the quantum path integral formulation of a field theory model an anomaly
arises when the functional measure is not invariant under a symmetry
transformation of the Lagrangian. In this paper, generalizing previous work
done on the point particle, we show that even at the classical level we can
give a path integral formulation for any field theory model. Since classical
mechanics cannot be affected by anomalies, the measure of the classical path
integral of a field theory must be invariant under the symmetry. The classical
path integral measure contains the fields of the quantum one plus some extra
auxiliary ones. So, at the classical level, there must be a sort of
"cancellation" of the quantum anomaly between the original fields and the
auxiliary ones. In this paper we prove in detail how this occurs for the chiral
anomaly.Comment: 26 pages, Latex, misprint fixed, a dedication include
Analysis of Friction Stir Processed Surface Quality of AA2098 Aluminum Alloy for Aeronautical Applications
FSP is a relatively new technique that changes the microstructure on the surface of the material to improve mechanical properties in the desired zone. This study aimed to investigate the surface quality of AA2098 sheets after being subjected to friction stir processing under different conditions of feed rate and rotational speed. A DoE analysis was developed with two factors, feed rate and rotational speed, and three different levels of 75, 100, 125 mm/min and 1000, 1250, 1500 rpm respectively, in order to assess the processed surface quality. The Sa parameter was used to represent the surface quality in different zones of the process, near entrance tool, middle and near exit tool, and ANOVA analysis was conducted. The results indicated that only the position and feed rate have a statistical influence on surface roughness. Additionally, the surface quality is strongly affected by the position relative to the entrance of the tool and the side (retreating or advancing sides). The roughness was found to be significantly lower on the advancing side rather than on the retreating side
Confronto dei contenuti formativi delle scuole di specializzazione dell'area di sanitĂ pubblica: le basi razionali per una proposta di core curriculum per il percorso formativo universitario ex art. 38, D.Lgs 81/2008
E' un confronto dei contenuti formativi delle scuole di specializzazione dell'area di sanità pubblica secondo il nuovo ordinamento al fine della proposta di core curriculum per il percorso formativo universitario ex art. 38, D.Lgs 81/2008 per specializzati in Igiene e Medicina legale, che conseguire i requisiti formativi per la nomina di Medico competente. Nel confronto si ravvisano carenze formative per quanto riguarda il contenuto di valutazione del rischio e prevenzione per gli specializzandi in Medicina legale, mentre carente è il contenuto in approfondimento clinico-diagnostico per gli specializzandi in Igiene. Si propone uno scheda di formazione annuale di percorso universitario
Predicting workout quality to help coaches support sportspeople
The support of a qualified coach is crucial to keep the motivation of sportspeople high and help them pursuing an active lifestyle. In this paper,we discuss the scenario in which a coach follows sportspeople remotely by means of an eHealth platform, named u4fit. Having to deal with several users at the same time, with no direct human contact, means that it is hard for coaches to quickly spot who, among the people she follows, needs a more timely support. To this end, in this paper we present an automated approach that analyzes the adherence of sportspeople to their planned workout routines. The approach is able to suggest to the coach the sportspeople who need earlier support due to a poor performance. Experiments on real data, evaluated through classic accuracy metrics, show the effectiveness of our approach
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