Vocal tecnology: A normalization approach

From the 1990s onwards the use of digital technology for voice and image transmission (GSM mobile telephones, satellite transmissions and Frame Relay and ATM networks) has brought about the convergence of information technology and telecommunications, leading to the birth of the ICT (Information & Communication Technologies) sector. Currently, internal telephone networks, LANs, internet connections and geographical data transmission networks are being unified in most organizations of a certain size

Proprieta' di Algebra lineare per problemi di stabilita' finita

In this paper we characterize some properties of linear algebra for the resolution of finite stability problem. In particular, we consider some important properties of the stochastic matrix in order to study some economic stability problem

A Variational Approach to Perturbed Discrete Anisotropic Equations

We continue the study of discrete anisotropic equations and we will provide new multiplicity results of the solutions for a discrete anisotropic equation. We investigate the existence of infinitely many solutions for a perturbed discrete anisotropic boundary value problem. The approach is based on variational methods and critical point theory

Spatial Filtering with a Pyramid Wavefront Sensor on the High Order Testbench

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Validation and reliability of a new PC-controlled device for the evaluation of key pinch strength in healthy adults

Objective: Hand muscle strength assessment is widespread and can be a useful marker in the evaluation and monitoring of subjects at different ages and health conditions. This study aimed at validating and determining the reliability of a new digital device for evaluation of hand pinch strength by comparing it with a well-validated hand strength assessment device, the Jamar hydraulic hand dynamometer. Methods: In 65 healthy subjects, (males / females: 29 / 36), mean age 40.3±18.0 (range: 19.3 - 76.5) years, hand pinch strength and hydraulic hand dynamometer were used to assess hand strength following a testing protocol. Only the dominant hand was tested. Evaluations were performed considering gender, hand dominance, body mass index and age, according to the standardized testing protocol. The mean of three consecutive grip tests and lateral pinch tests was recorded. Results: There was a strong correlation (p<0.0001) between the hydraulic hand dynamometer and hand pinch strength tests. Both mean strengths measured by hydraulic hand dynamometer and hand pinch strength in females were significantly lower than in males (P<0.001), the grip strength being 34.75% and the lateral pinch test 27.83% weaker than in males. Multivariate analysis indicated that the strength expressed by the hand pinch strength pinch test remained significantly associated with the results of hydraulic hand dynamometer (p<0,001), independent of age and body weight. Conclusions: hand pinch strength and hydraulic hand dynamometer have been shown to be significantly correlated with each other in subjects of different ages, sex and body mass index. The hand pinch strength device has been proven to be a reliable tool for measuring maximal isometric strength by lateral pinch test. This device can be used for quick and inexpensive numerical evaluation of muscular strength in cases as the elderly in communities, bedridden patients, and during drug therapies presumed to be strength affecting

Numerical control matrix rotation for the LINC-NIRVANA Multi-Conjugate Adaptive Optics system

LINC-NIRVANA will realize the interferometric imaging focal station of the Large Binocular Telescope. A double Layer Oriented multi-conjugate adaptive optics system assists the two arms of the interferometer, supplying high order wave-front correction. In order to counterbalance the field rotation, mechanical derotation for the two ground wave-front sensors, and optical derotators for the mid-high layers sensors fix the positions of the focal planes with respect to the pyramids aboard the wave-front sensors. The derotation introduces pupil images rotation on the wavefront sensors: the projection of the deformable mirrors on the sensor consequently change. The proper adjustment of the control matrix will be applied in real-time through numerical computation of the new matrix. In this paper we investigate the temporal and computational aspects related to the pupils rotation, explicitly computing the wave-front errors that may be generated.Comment: 6 pages, 2 figures, presented at SPIE Symposium "Astronomical Telescopes and Instrumentation'' conference "Adaptive Optics Systems II'',Sunday 27 June 2010, San Diego, California, US

Mid-Infrared High-Contrast Imaging of HD 114174 B : An Apparent Age Discrepancy in a "Sirius-Like" Binary System

We present new observations of the faint "Sirius-like" companion discovered to orbit HD 114174. Previous attempts to image HD 114174 B at mid-infrared wavelengths using NIRC2 at Keck have resulted in a non-detection. Our new L'-band observations taken with the Large Binocular Telescope and LMIRCam recover the companion ($\Delta L$ = 10.15 $\pm$ 0.15 mag, $\rho$ = 0.675'' $\pm$ 0.016'') with a high signal-to-noise ratio (10 $\sigma$). This measurement represents the deepest L' high-contrast imaging detection at sub-arcsecond separations to date, including extrasolar planets. We confirm that HD 114174 B has near-infrared colors consistent with the interpretation of a cool white dwarf ($J-L'$ = 0.76 $\pm$ 0.19 mag, $K-L'$ = 0.64 $\pm$ 0.20). New model fits to the object's spectral energy distribution indicate a temperature $T_{\rm eff}$ = 4260 $\pm$ 360 K, surface gravity log g = 7.94 $\pm$ 0.03, a cooling age t$_{c} \approx$ 7.8 Gyr, and mass $M$ = 0.54 $\pm$ 0.01 $M_{\odot}$. We find that the cooling age given by theoretical atmospheric models do not agree with the age of HD 114174 A derived from both isochronological and gyrochronological analyses. We speculate on possible scenarios to explain the apparent age discrepancy between the primary and secondary. HD 114174 B is a nearby benchmark white dwarf that will ultimately enable a dynamical mass estimate through continued Doppler and astrometric monitoring. Efforts to characterize its physical properties in detail will test theoretical atmospheric models and improve our understanding of white dwarf evolution, cooling, and progenitor masses.Comment: 6 pages, 3 figures, to be published in the Astrophysical Journal Letter