A minimization problem for the sum of weighted convolutions’ difference and a novel approach to the inverse problem of ECG- and PPG-signals recovering

In this paper, we consider an unstudied problem of approximation of an observed pulse train by by a quasiperiodic signal generated by a pulse with a given pattern (reference) shape. The quasiperiodicity allows variation of time intervals between repetitions of the pattern pulse, as well as nonlinear expansions of the pattern in time. Such inverse problems are common in electrocardiogram (ECG) and photoplethysmogram (PPG) features extraction. The following two variants of the problem are considered. In the first variant, the number of the pulse repetitions is unknown, while in the second one, that number is given. The polynomial-time solvability of the both variants of the problem is constructively proved.

Conductance Quantization Behavior in Pt/SiN/TaN RRAM Device for Multilevel Cell

In this work, we fabricated a Pt/SiN/TaN memristor device and characterized its resistive switching by controlling the compliance current and switching polarity. The chemical and material properties of SiN and TaN were investigated by X-ray photoelectron spectroscopy. Compared with the case of a high compliance current (5 mA), the resistive switching was more gradual in the set and reset processes when a low compliance current (1 mA) was applied by DC sweep and pulse train. In particular, low-power resistive switching was demonstrated in the first reset process, and was achieved by employing the negative differential resistance effect. Furthermore, conductance quantization was observed in the reset process upon decreasing the DC sweep speed. These results have the potential for multilevel cell (MLC) operation. Additionally, the conduction mechanism of the memristor device was investigated by I-V fitting.

Investigation of time domain characteristics of negative capacitance FinFET by pulse-train approaches

The HfO2-based ferroelectric field effect transistors (FeFET) have been widely studied for their ability in breaking the Boltzmann limit and the potential to be applied to low-power circuits. This article systematically investigates the transient response of negative capacitance (NC) fin field-effect transistors (FinFETs) through two kinds of self-built test schemes. By comparing the results with those of conventional FinFETs, we experimentally demonstrate that the on-current of the NC FinFET is not degraded in the MHz frequency domain. Further test results in the higher frequency domain show that the on-state current of the prepared NC FinFET increases with the decreasing gate pulse width at pulse widths below 100 ns and is consistently greater (about 80% with NC NMOS) than the on-state current of the conventional transistor, indicating the great potential of the NC FET for future high-frequency applications.

Nonlinear pulse reshaping in a typically designed silicon on insulator waveguide and its application to generate high repetition rate pulse train

A Silicon on Insulator (SOI) planar waveguide is designed here possessing a small group velocity dispersion (β2) ∼ 2.212 (ps2/m) with quite high nonlinear coefficient (γ) of ∼ 360.57 (W.m)-1. The so designed waveguide is capable of reshaping a Super-Gaussian input optical pulse into parabolic pulse (PP), without any use of external gain. The same waveguide with relatively longer length is also able to generate triangular pulse (TP) by using positive chirp at the input. In both cases PP and TP are created at much shorter optimum length (Lopt) of few mm, when compared to previously reported works on normal dispersion optical fibers. The interaction of a pulse pair inside such a SOI waveguide is investigated also for the first time as per our knowledge to generate of a high frequency (~ 4.8 THz) pulse train, while lower repetition rate (~180 GHz) pulses are used at the input. This study as a whole enables one to have potential device applications in the domain of tunable high frequency (THz) pulse generators, optical signal processing and many more.