169,937 research outputs found
CAN EXPERIMENTAL TESTS OF BELL INEQUALITIES PERFORMED WITH PSEUDOSCALAR MESONS BE DEFINITIVE?
No full text
DOUBLE ENTANGLEMENT AND QUANTUM CRYPTOGRAPHY
No full textWe propose a quantum
transmission based on bi-photons, which are doubly-entangled both in
polarisation and phase. This scheme finds a natural application in quantum
cryptography, where we show that an eventual eavesdropper is bound to
introduce a larger error on the quantum communication than for a single
entangled bi-photon communication, when he steels the same information
Public Interventions Supporting Innovation in Small and Medium-Size Firms. Successes or Failures? A Probit Analysis
No full textThe aim of this work is to investigate the probability of success or failure of public interventions, made to support the development of some Italian firms. The great number of small and medium-size enterprises, placed in the Canavese area, north of Turin, Italy, has suffered, in the nineties, of a gap in technological innovation in their production. The Consortium for the Canavese Technological District (CCTD), a public local association established in 1993 specifically to support the firms of the area, has supplied them with some technological, innovative services, sustaining their growth. More exactly, some research centres, named Centres of Competence, were created, with the pre-existing structures of the Polytechnic of Turin and of the firm RTM (placed in Vico Canavese, Province of Turin): their targets were to supply innovative services to the local firms and to place technical machineries at the disposal of the local units, to support their innovation and competitiveness. The present research analyzes a central point: which has been the impact of these services? Which is the probability that a public o private intervention to innovate has success and brings economic growth to the involved firms? This objective is achieved with a Probit Model, built on a panel of 103 firms, that covers a 6-year range (from 1999 to 2004) and contains their balance-sheets data and the technical information regarding their collaborations with the Centres; the results highlight the role of a solid patrimonial stability, of the choice of the right innovations to apply to the production processes as well as the importance of a high previous technological status of the involved enterprises.Innovation probability, Public interventions, Firms growth, Qualitative choice models
On the measurement of photon flux in parametric down-conversion
No full textWe report the measurement of the photons flux produced in parametric down-conversion, performed
in photon counting regime with actively quenched silicon avalanche photodiodes as single photon
detectors. Measurements are done with the detector in a well defined geometrical and spectral situation.
By comparison of the experimental data with the theory, a value for the second order
susceptibilities of the non linear crystal can be inferred
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