2,236 research outputs found
Cost Benefit Analysis of the Community Patent
The creation of a European Community Patent (COMPAT) came a step closer this month when Sweden brokered a preliminary agreement on the issue. In this working paper, Senior Resident Fellow Bruno van Pottelsberghe and Jérôme Danguy use simulations to take a look at the advantages, disadvantages, winners and losers from the creation of the COMPAT. They find that it would drastically reduce the relative patenting costs for applicants while generating more income for the European Patent Office and increased savings for the business sector. They also explain that the lost of economic rents for patent attorneys, translators and lawyers specialised in patent litigation and the drop of controlling power for national patent offices may explain why there has been such resistance to the COMPAT thus far.
Non-destructive testing of composite plates by holographic vibrometry
We report on a wide-field optical monitoring method for revealing local
delaminations in sandwich-type composite plates at video-rate by holographic
vibrometry. Non-contact measurements of low frequency flexural waves is
performed with time-averaged heterodyne holography. It enables narrowband
imaging of local out-of-plane nanometric vibration amplitudes under sinusoidal
excitation, and reveals delamination defects, which cause local resonances of
flexural waves. The size of the defect can be estimated from the first
resonance frequency of the flexural wave and the mechanical parameters of the
observed layer of the composite plate
Laser beam shaping for enhanced Zero-Group Velocity Lamb modes generation
Optimization of Lamb modes induced by laser can be achieved by adjusting the
spatial source distribution to the mode wavelength (). The
excitability of Zero-Group Velocity (ZGV) resonances in isotropic plates is
investigated both theoretically and experimentally for axially symmetric
sources. Optimal parameters and amplitude gains are derived analytically for
spot and annular sources of either Gaussian or rectangular energy profiles. For
a Gaussian spot source, the optimal radius is found to be .
Annular sources increase the amplitude by at least a factor of 3 compared to
the optimal Gaussian source. Rectangular energy profiles provide higher gain
than Gaussian ones. These predictions are confirmed by semi-analytical
simulation of the thermoelastic generation of Lamb waves, including the effect
of material attenuation. Experimentally, Gaussian ring sources of controlled
width and radius are produced with an axicon-lens system. Measured optimal
geometric parameters obtained for Gaussian and annular beams are in good
agreement with theoretical predictions. A ZGV resonance amplification factor of
2.1 is obtained with the Gaussian ring. Such source should facilitate the
inspection of highly attenuating plates made of low ablation threshold
materials like composites.Comment: 11 pages, 12 figure
Probabilistic Knowledge-Based Programs
International audienceWe introduce Probabilistic Knowledge-Based Programs (PKBPs), a new, compact representation of policies for factored partially observable Markov decision processes. PKBPs use branching conditions such as if the probability of ϕ is larger than p, and many more. While similar in spirit to value-based policies, PKBPs leverage the factored representation for more compactness. They also cope with more general goals than standard state-based rewards, such as pure information-gathering goals. Compactness comes at the price of reactivity, since evaluating branching conditions on-line is not polynomial in general. In this sense, PKBPs are complementary to other representations. Our intended application is as a tool for experts to specify policies in a natural, compact language, then have them verified automatically. We study succinctness and the complexity of verification for PKBPs
The policy dilemma of the unitary patent. Bruegel Working Paper 2014/13, 27 November 2014
This paper provides new evidence about the budgetary consequences – for patent offices – of the coexistence of the forthcoming Unitary Patent (UP) with the current European Patent (EP). Simulation results illustrate a dilemma between (1) high UP renewal fees to ensure enough financial income for all national patent offices (NPOs) and (2) low UP renewal fees to make the UP system affordable, with very few NPOs losing on financial revenues. The simulations help to understand the positions of several patent offices, and underline an alternative way to proceed with the negotiations while reducing financial risks for the whole system
Transition from plasma- to Kerr-driven laser filamentation
While filaments are generally interpreted as a dynamic balance between Kerr
focusing and plasma defocusing, the role of the higher-order Kerr effect (HOKE)
is actively debated as a potentially dominant defocusing contribution to
filament stabilization. In a pump-probe experiment supported by numerical
simulations, we demonstrate the transition between two distinct filamentation
regimes at 800\,nm. For long pulses (1.2 ps), the plasma substantially
contributes to filamentation, while this contribution vanishes for short pulses
(70 fs). These results confirm the occurrence, in adequate conditions, of
filamentation driven by the HOKE rather than by plasma.Comment: 6 pages, 4 figures. Accepted for publication in Physical Review
Letter
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