Search results for "symmetry"
showing 10 items of 3576 documents
Rubber Forming Processes of Thin Sheets
1999
In the last decade flexible media have been increasingly utilized in sheet metal drawing processes in order to reduce the tooling cost and to improve the product quality. In the present paper an axisymmetric deep drawing process of thin steel sheets is taken into account: in particular a flexible pad is utilized in order to simplify the tooling set. The process mechanics is investigated through numerical simulations and experimental tests with the aim to find out a proper set of operative parameters allowing the stamping of sound components and to highlight the particular deformation path of the drawing cup. The comparison between the numerical predictions and the experimental verification …
Monopoles and dualities in 3d N=2 quivers
2021
Seiberg-like dualities in 2+1d quiver gauge theories with 4 supercharges are investigated. We consider quivers made of various combinations of classical gauge groups U(N), Sp(N), SO(N) and SU(N). Our main focus is the mapping of the supersymmetric monopole operators across the dual theories. There is a simple general rule that encodes the mapping of the monopoles upon dualizing a single node. This rule dictates the mapping of all the monopoles which are not dressed by baryonic operators. We also study more general situations involving baryons and baryon-monopoles, focussing on three examples: SU−Sp, SO−SO and SO−Sp quivers.
All N=(8,0) AdS3 solutions in 10 and 11 dimensions
2021
We classify AdS(3) solutions preserving N = (8, 0) supersymmetry in ten and eleven dimensions and find the local form of each of them. These include the AdS(3)xS(6) solution of [1] and the embeddings of AdS(3) into AdS(4)xS(7), AdS(5)xS(5), AdS(7)/Z(k)xS(4) and its IIA reduction within AdS(7). More interestingly we find solutions preserving the superconformal algebras f4, su(1,1|4), osp(4*|4) on certain squashings of the 7-sphere. These solutions asymptote to AdS(4)xS(7) and are promising candidates for holographic duals to defects in Chern-Simons matter theories.
Evaluation of Planar Symmetry Preferences through a Physics-based Operator
2010
Face Expression Recognition through Broken Symmetries
2008
Security systems, criminology, physical access control and man-machine interactions are examples of applications where recognition of human faces may be crucial. In the present paper a new signature, based on a measure of axial symmetry called DST, is proposed as a significant feature to analyze facial expressions. The measure of symmetry is an elaborate difference between the internal and external symmetry kernels of an object. The idea here is to use the evolution of the symmetry measure of a face over an ordered set of its sub-images. We claim that different evolutionary trends will represent different face expressions. The proposed signature has been tested on several face databases (ps…
FiST: a Physics-based Operator for Planar Symmetry Preferences
2012
THE INFLUENCE OF TEXTURE SYMMETRY IN MARKER POINTING: EXPERIMENTING WITH HUMANS AND ALGORITHMS
2011
Symmetry plays a fundamental role in aiding the visual system, to organize its environmental stimuli and to detect visual patterns of natural and artificial objects. Various kinds of symmetry exist, and we will discuss how internal symmetry due to textures influences the choice of direction in visual tasks. Two experiments are presented: the first, with human subjects, deals with the effect of textures on preferences for a pointing direction. The second emulates the performances obtained in the first through the use of an algorithm based on a physic metaphor. Results from both experiments are shown and comment.
Endogenous asymmetry and cooperative R&D in linear duopoly with spillovers
2009
In a standard model of R&D followed by linear Cournot competition, firm asymmetry is sustainable as equilibrium with non cooperative R&D if and only if the productivity of research is sufficiently large relative to the benefits of imitation. Increasing spillovers distribute R&D results among asymmetric competitors, causing price, firm asymmetry, and joint profit to reduce. With zero spillovers, a symmetric joint lab dominates asymmetric R&D competition in terms of social welfare and consumer surplus, but is sometimes dominated in terms of joint profit. Raising spillovers encourage symmetric collusion but makes the latter potentially harmful to consumers. (JEL : C72; L13; O32).
Labor Productivity and Okun’s law: An empirical application to Italian regional panel data
2012
Okun’s law, named for its proposer, Arthur Okun, was first applied during the 1960s in the USA to describe the relationship between economic growth and unemployment fluctuations. Several attempts were later made to test the empirical applicability of the relationship to different countries and historical periods. Heterogeneous results were generally found in estimating Okun’s coefficient, depending on the sample and context analysed. The main goal of this paper is to analyze the relevance of Okun’s law to Italian regions. We perform a panel analysis to estimate the influence of asymmetry and local market differences on Okun’s relationship. Moreover, observing particularly low values of part…