1,721,383 research outputs found
[Juvenilis macular degeneration in a family affected by cystinuria].Greco GM, Magli A, Bonavolonta G, Andria G.
No full text
Step-like waveform analysis to measure mechanical torques
No full textA new technique is proposed to measure mechanical torque of rotating machinery via computer processing. This aim is pursued performing an FFT-realisation of a differentiating FIR-filter by which the sampled speed step-like waveform, produced during a start-up transient of the motor, is processed. The derivative of the speed signal is executed directly in the frequency domain, so avoiding preventive manipulations of the step-like waveform in the time domain. Optimal results have been achieved from the point of view of processing speed and of reduction of the noise level
X-linked ichthyosis due to steroid sulfatase deficiency associated with hypogonadism and anosmia
No full textWindows and Interpolation Algorithms to Improve Electrical Measurement Accuracy
No full textAn FFT-based measurement technique, which can be easily used to determine accurately the frequency, amplitude, and phase of all the harmonic and interharmonic components of a distorted signal, is examined. Suitable windows and interpolation algorithms are examined in order to reduce undesirable effects due to spectral leakage caused by a sampling process that is not synchronized. Several results concerning the application of different windows on a set of simulated signals are compared to verify the capability of the proposed procedure. The influence of the noise is examined to study the filtering properties of the weighting functions
Lysosomal storage diseases: from pathophysiology to therapy.
No full textLysosomal storage diseases are a group of rare, inborn, metabolic errors characterized by deficiencies in normal lysosomal function and by intralysosomal accumulation of undegraded substrates. The past 25 years have been characterized by remarkable progress in the treatment of these diseases and by the development of multiple therapeutic approaches. These approaches include strategies aimed at increasing the residual activity of a missing enzyme (enzyme replacement therapy, hematopoietic stem cell transplantation, pharmacological chaperone therapy and gene therapy) and approaches based on reducing the flux of substrates to lysosomes. As knowledge has improved about the pathophysiology of lysosomal storage diseases, novel targets for therapy have been identified, and innovative treatment approaches are being developed
Instantaneous power measurement in time‐frequency domain
No full textThe paper deals with an originai application oj the Short-Time Fourier Transform (STFT) to instantaneous power measurements. This technique can be easily implemented in a dedicated instrument to perform accurate time-frequency analysis ofthe time-varying harmonic contents ofnetwork powers (in their active and imaginary components), which are typically non-stationary signals. Moreover, new algorithms have been examined carefully and developed to attain high levels ofaccuracy,flexibility and efficiency through STFT-PD (Power Distribution). Particularly, optimized interpolationformulas were used, derivedfrom the windowing theory to reduce the negative effects due to leakage during instantaneousfrequency changes. The effectiveness ofthe suggested technique and, particularly, the high level of accuracy achieved in time-varying amplitude andfrequency measurements ofthe analysed components of instantaneous powers and currents has been proven by means of suitable simulations
Inverter drive signal processing via DFT and EKF
No full textTwo algorithms for estimating both the positive sequence fundamental symmetrical component and the frequency of the voltage system at the terminals of an inverter-fed three-phase motor are presented in this paper. The first one is based on the discrete Fourier transform of the instantaneous symmetrical component of the positive sequence and yields off-line estimates. The accuracy is improved by the application of flat-top windows which reduce leakage and negative interference effects. This algorithm can be used for microcomputer based tests and diagnostics of inverter drives. The second one is based on the extended Kalman filtering of the instantaneous symmetrical component of the positive sequence and gives on-line unbiased estimates. The harmonic components are rejected because they are treated as measurement errors. The EKF algorithm may lead to the development and implementation of adaptive control techniques. Several results obtained from these algorithms are reported and compared in this paper
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