Validation of a smart mirror for gesture recognition in gym training performed by a vision-based deep learning system

This paper illustrates the development and validation of a smart mirror for sports training. The application is based on the skeletonization algorithm MediaPipe and runs on an embedded device Nvidia Jetson Nano equipped with two fisheye cameras. The software has been evaluated considering the exercise biceps curl. The elbow angle has been measured by both MediaPipe and the motion capture system BTS (ground truth), and the resulting values have been compared to determine angle uncertainty, residual errors, and intra-subject and inter-subject repeatability. The uncertainty of the joints’ estimation and the quality of the image captured by the cameras reflect on the final uncertainty of the indicator over time, highlighting the areas of improvement for further development

SLaMA-URM method for the seismic vulnerability assessment of UnReinforced Masonry structures: Formulation and validation for a substructure

An analytical procedure based on the SLaMA (Simplified Lateral Mechanism Analysis) method is proposed for the seismic vulnerability assessment of UnReinforced Masonry (URM) structures. The procedure considers an equivalent frame discretization for the structure (pier, spandrel, and joint elements) and includes: (i) the evaluation of moment‒rotation capacity curves at each pier-spandrel subassembly; (ii) the assessment of the hierarchy of strength in each subassembly; and (iii) the calculation of the structure capacity curve according to the expected failure mechanism. Validation of the proposed SLaMA-URM procedure is achieved in a one-story URM substructure tested under lateral cyclic loading. The analytical predictions are compared with numerical ones from a 2D continuous finite element (FE) model based on a macro-modelling strategy. The flexural capacity of the components is estimated using a monolithic beam analogy, and the results compared with those from traditional sectional analysis. The influence of the substructure geometry on the hierarchy of strength at the subassembly and global levels is investigated. An analytical formulation of the pier-spandrel joint strength is also proposed to be considered in the assessment of the hierarchy of strength. The method is validated for a one-story substructure subjected to lateral in-plane loading. Results, in terms of crack patterns and capacity curves, are in relatively good agreement with the experimental and FE results, even when a bilinear curve approximation is used. The potential of the SLaMA-URM method for the seismic assessment of URM buildings is demonstrated, whose application to a larger URM structure is planned as a subsequent study

Photoproduction of h_c

Using the NRQCD factorization formalism, we calculate the total cross section for the photoproduction of h_c mesons. We include color-octet and color-singlet mechanisms as well as next-to-leading order perturbative QCD corrections. The theoretical prediction depends on two nonperturbative matrix elements that are not well determined from existing data on charmonium production. For reasonable values of these matrix elements, the cross section is large enough that the h_c may be observable at the E831 experiment and at the HERA experiments.Comment: Revtex file 8 pages, 1 figure. Macros needed: epsf,floats,rotate Minor typos changed, and reference added. Version to be published in Phys.Rev.

Integrated photonic quantum gates for polarization qubits

Integrated photonic circuits have a strong potential to perform quantum information processing. Indeed, the ability to manipulate quantum states of light by integrated devices may open new perspectives both for fundamental tests of quantum mechanics and for novel technological applications. However, the technology for handling polarization encoded qubits, the most commonly adopted approach, is still missing in quantum optical circuits. Here we demonstrate the first integrated photonic Controlled-NOT (CNOT) gate for polarization encoded qubits. This result has been enabled by the integration, based on femtosecond laser waveguide writing, of partially polarizing beam splitters on a glass chip. We characterize the logical truth table of the quantum gate demonstrating its high fidelity to the expected one. In addition, we show the ability of this gate to transform separable states into entangled ones and vice versa. Finally, the full accessibility of our device is exploited to carry out a complete characterization of the CNOT gate through a quantum process tomography.Comment: 6 pages, 4 figure

Deep inelastic J/ψJ/\psi production at HERA in the kTk_T-factorization approach and its consequences for the nonrelativistic QCD

In the framework of the $k_T$-factorization approach, we analyse the inclusive and inelastic production of $J/\psi$ particles in deep inelastic $ep$ scattering. We take into account both colour-singlet and colour-octet production channels. We inspect the sensitivity of theoretical predictions to the choice of model parameters. Our theoretical results agree reasonably well with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure

Photonic Quantum Information Applications of Patterned Liquid Crystals

In this paper we review recent results we obtained in the field of photonic quantum information that were made possible by the introduction of patterned non-uniform liquid crystal cells known as ''q-plates'': (i) the generation of entangled states of polarization and orbital angular momentum of a photon; (ii) the transfer of a qubit of quantum information from the spin to the orbital angular momentum of photons and vice versa; (iii) the Hong-Ou-Mandel coalescence in the same outgoing mode of a beam-splitter of two photons having nonzero orbital angular momentum; (iv) the universal optimal quantum cloning of orbital-angular-momentum-encoded qubits

Measurement of the Lifetime Difference Between B_s Mass Eigenstates

We present measurements of the lifetimes and polarization amplitudes for B_s --> J/psi phi and B_d --> J/psi K*0 decays. Lifetimes of the heavy (H) and light (L) mass eigenstates in the B_s system are separately measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time. Using 203 +/- 15 B_s decays, we obtain tau_L = (1.05 +{0.16}/-{0.13} +/- 0.02) ps and tau_H = (2.07 +{0.58}/-{0.46} +/- 0.03) ps. Expressed in terms of the difference DeltaGamma_s and average Gamma_s, of the decay rates of the two eigenstates, the results are DeltaGamma_s/Gamma_s = (65 +{25}/-{33} +/- 1)%, and DeltaGamma_s = (0.47 +{0.19}/-{0.24} +/- 0.01) inverse ps.Comment: 8 pages, 3 figures, 2 tables; as published in Physical Review Letters on 16 March 2005; revisions are for length and typesetting only, no changes in results or conclusion

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured