Tunable Acoustic Filter with High-Electroacoustic Coupling Resonators

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In data-parallel optimization of machine learning models, workers collaborate to improve their estimates of the model: more accurate gradients allow them to use larger learning rates and optimize faster. In the decentralized setting, in which workers communicate over a sparse graph, current theory fails to capture important aspects of real-world behavior. First, the `spectral gap' of the communication graph is not predictive of its empirical performance in (deep) learning. Second, current theory does not ex

RR-interval time series often present impulses corresponding to short-duration increases or decreases in the heart rate, most probably due to bursts in autonomic activity. The time-domain heartrate variability index pNN50 is obviously linked to these spikes. As linear filtering is not appropriate for the extraction of these spikes, we developed a nonlinear algorithm for this task. In this study we demonstrate the potential of this approach to assess caffeine-induced changes in the autonomic tone, and discus

This paper presents a noise reduction technique for Terahertz imaging based on modulating the THz source in order to transpose the signal at the output of the rectifier at a higher frequency where there is no 1/f noise and then filtering with a high Q bandpass filter centred at the modulation frequency. The filtering circuit, based on a 16-path passive switched capacitor (SC) bandpass filter, is modeled analytically. The presented technique is implemented in a test chip with a 130 nm process. Measurement re

The respiratory rate is an important vital sign that needs to be monitored continuously in clinical and non-clinical health monitoring applications. It is commonly estimated from electrocardiogram (ECG)-derived respiratory waveforms such as the respiratory sinus arrhythmia~(RSA) and the ECG R peak amplitude~(RPA). Current methods combine respiratory information from these two waveforms but produce large delays in estimating the respiratory rate. In this work, the power of the outputs of a bank of order-3 FI

In this work, the potential of magnetron sputtered magnesium fluoride (MgF2) and MgF2 containing composite coatings for coloured solar collector glazing is investigated. Coloured thin-film interference coatings on the reverse side of the collector cover glass give solar collectors an aesthetic appearance, which facilitates their integration into the building’s envelope. Hereby, integration means that the solar collector is no longer recognisable as technical device. Moreover, its appearance is the one of an

This paper presents a novel tunable bandpass filter design with independent control of both the centre frequency and the bandwidth by means of analogue-series and digital-shunt MEMS capacitors. The filter is designed for operation in X and Ku bands with 4 pre-selected centre frequencies (from 10 GHz to 14 GHz) and with a bandwidth tunability of 70% (variable between 500 MHz and 1 GHz). The filter originally includes a fine frequency tuning to correct the centre frequency position that slightly and intrinsic

Multichannel sound field reproduction techniques, such as Wave Field Synthesis (WFS) and Sound Field Reconstruction (SFR), define loudspeaker filters in the frequency domain. However, in order to use these techniques in practical systems, one needs to convert these frequency-domain characteristics to practical and efficient time-domain digital filters. Additional limitation of SFR comes from the fact that it uses a numerical matrix pseudoinversion procedure, where the obtained filters are sensitive to numer

An extension of the Jot reverberator is presented, producing binaural late reverberation where the interaural coherence can be controlled as a function of frequency such that it matches the frequency-dependent interaural coherence of a reference binaural room impulse response (BRIR). The control of the interaural coherence is implemented using linear filters outside the reverberator’s recursive loop. In the absence of a reference BRIR, these filters can be calculated from an HRTF set.

A digital controller for piezoelectric motors was developed. The controller tunes the driving frequency in order to maximize the power transmitted to the motor. A maximum of power is absorbed when the resonant frequency of the mechanical and electrical part of the piezoelectric motor are equal. This frequency varies in the first place because of the applied force. The control method consists of comparing two values of the transmitted power, measured at different moments, and deciding as a function of the re

In many applications, the sampling frequency is limited by the physical characteristics of the components: the pixel pitch, the rate of the A/D converter, etc. A low-pass filter is then often applied before the sampling operation to avoid aliasing. However, when multiple copies are available, it is possible to use the information that is inherently present in the aliasing to reconstruct a higher resolution signal. If the different copies have unknown relative offsets, this is a non-linear problem in the off

Particle filters are now established as the most popular method for visual tracking. Within this framework, it is generally assumed that the data are temporally independent given the sequence of object states. In this paper, we argue that in general the data are correlated, and that modeling such dependency should improve tracking robustness. To take data correlation into account, we propose a new model which can be interpreted as introducing a likelihood on implicit motion measurements. The proposed model

This paper proposes two frequency based methods for parallel active filtering of current harmonics in utility grids. Active Filter (AF) reference prediction and AF current control are the two key-points to obtain high performances. This paper deals with the AF reference prediction. The two proposed methods are based on the Fourier Series and its implementation on DSP. They belong to two prediction structures: the open-loop structure which predicts the reference currents from the load currents, and the close

We consider using spline interpolation to improve the standard filtered back-projection (FBP) tomographic reconstruction algorithm. In particular, we propose to link the design of the filtering operator with the interpolation model that is applied to the sinogram. The key idea is to combine the ramp filtering and the spline fitting process into a single filtering operation. We consider three different approaches. In the first, we simply adapt the standard FBP for spline interpolation. In the second approach

Direct observation of polarization distribution at nanoscale by scanning force microscopy across partially etched Pb(Zr,Ti)O-3 film ferroelectric capacitors with size 2x3 mum and preferential orientation (111) has revealed an anomalous polarization pattern characterized by polarization inversion in the center of the capacitor. This self-structured pattern is reproducible and independent on the spontaneous polarization orientation, but strongly influenced by the film texture and capacitor size. In particular

We have examined the diameter response of rat femoral artery segments in the presence and absence of endothelium to changes in flow rate. The segments were isolated, mounted on microcannulae, maintained at 37 degrees C, and perfused at 90 mmHg with Tyrode's solution. The external arterial diameter was measured using video-microscopy. The mean control diameter was 741+/-22 microm (mean+/-SEM,n=7). The arteries were preconstricted to 75+/-1% of the control diameter with a superfusion of 1 microM norepinephrin

Dielectric breakdown of (Pb,La)(Zr,Ti)O-3(PLZT) film capacitors with Pt and SrRuO3 electrodes, in its initial or virgin state and after voltage cycling that causes polarization fatigue, is studied by constant-current measurements. It is shown that for different types of PLZT capacitors, the breakdown onset is controlled by the critical charge flown through the film (charge to breakdown) rather than the voltage applied to the capacitor. The charge to breakdown for the asymmetrical Pt/SrRuO3/PLZT/Pt capacitor

Role of Pt and SRO electrodes in polarization fatigue of PLZT film ferroelectric capacitors is studied. We show that asymmetrical Pt/SRO/PLZT/Pt structure exhibits unusual dependence of the endurance of switching polarization on the driving ac electric field amplitude. Specifically, for high ac electric field amplitude it shows a good switching endurance similar to SRO/PLZT/SRO capacitors, whereas for amplitude lower than 80 kV/cm a pronounced polarization fatigue similar to that of conventional Pt/PLZT/Pt

Constraints related to the Distinctive Regions and Modes (DRM) speech production model are incorporated in the framework of speech analysis by inverse filtering. It is shown that the analogy between Auto-Regressive modeling and acoustic models based on acoustic tubes is still respected when using tubes with unequal length elementary sections. This analogy can be exploited for the inversion of the synthesis process using a method related to Burg's estimation method. Experimental results show that an improvem

Machine-tool axes for high-speed machining make great demands on the mechanical system, the actuators, and the numerical control. They require a high stiffness, a high bandwidth, and a precise motion at maximum speed. Linear motors as direct drives for machine-tool axes provide the basis to fulfil these requirements. They eliminate the gear-related problems of rotary drives with lead-screw transmission (from rotary to linear motion). In research and industrial projects, linear drives are already successfull

High-speed optical guided-wave switches and modulators are promising components for present and future applications in lightwave communication and measurement systems, or more generally for optical signal processing purposes. Integrated electro-optic modulators with bandwidth extending over a few gigahertz and low drive voltages are now commercially available. Due to their potential applications, bandwidth characterization is an important feature of the metrology of these devices and is often limited by the

Tunable Acoustic Filter with High-Electroacoustic Coupling Resonators

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Beyond spectral gap (extended): The role of the topology in decentralized learning

Extraction and Analysis of Short-Time Excursions in RR-interval Time Series

A noise reduction circuit technique for CMOS terahertz imaging

Estimating the real-time respiratory rate from the ECG with a bank of notch filters

Potential of magnetron sputtered magnesium fluoride containing thin films for the multilayer design of coloured coatings for solar collector glazing

Centre frequency and bandwidth tunable bandpass filter based on RF MEMS (10-14GHz)

Designing Practical Filters For Sound Field Reconstruction

Binaural reverberation using a modified Jot reverberator with frequency- dependent interaural coherence matching

Digital control of a piezoelectric motor

Aliasing is Good for You: Joint Registration and Reconstruction for Super-Resolution

An Implicit Motion Likelihood for Tracking with Particle Filters

Control of the frequency spectrum with the help of open loop and closed loop algorithms in active filters

Filter Design for Filtered Back-Projection Guided by the Interpolation Model

Unusual size effect on the polarization patterns in micron-size Pb(Zr,Ti)O-3 film capacitors

In vitro diameter response of rat femoral artery to flow in the presence and absence of endothelium

Dielectric breakdown in (Pb,La)(Zr,Ti)O-3 ferroelectric thin films with Pt and oxide electrodes

Degradation of asymmetrical Pt/SRO/PLZT/Pt capacitors: Role of Pt and oxide electrodes

Acoustico-articulatory inversion of unequal-length tube models through lattice inverse filtering

Accelerometer - enhanced speed estimation for linear - drive machine tool axes

Techniques for bandwidth measurements of optical guided-wave modulators