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Theoretical and experimental studies were conducted to investigate the impact of the cable capacitance during measurements of insulation resistance on the fast response time of a resistance-to-voltage converter. From a comparison of the results of simulation with the data obtained during the experiments, it was determined that the dependence characteristics of the settling time of resistance under measurement on the capacitance are identical to the analogous characteristics of electronic components of the resistance-to-voltage converter. It was experimentally proven that using T-shaped feedback in the resistance-to-voltage converter during the cable insulation resistance measurements reduces the settling time of the data by 1-3 times in comparison with a classical feedback system. Furthermore, when using the optimal parameters, the settling time of the resistance-to-voltage converter with T-shaped feedback depends to a lesser degree on the capacitance of the object under control.

This paper is devoted to demonstrate how a class of fractional-order chaotic systems can be controlled in a given finite time using just a single control input. First a novel fractional switching sliding surface is proposed with desired properties such as fast convergence to zero equilibrium and no steady state errors. At the second phase, a smooth reaching control law is derived to guarantee the occurrence of the sliding motion with a finite settling time. Owing to the integration of the control signal discontinuity, chattering oscillations are hindered from the controller. Rigorous stability analysis is performed to validate the design claims. The effects of high frequency external noises as well as modeling errors and dynamic variations are also taken into account, and the robustness of the closed-loop system is ensured. The proposed robust controller is realized for a class of chaotic fractional-order systems with one control input. In accordance, some remarks regarding the inclusion of mismatched uncertainties in the system dynamics are given. The robust functionality and quick convergence property as well as chatter-free attribute of the introduced non-smooth sliding mode technology are demonstrated using oscillation suppression of fractional-order chaotic Lorenz and financial systems.

In this paper, the finite-time synchronization between two delayed quaternion-valued neural networks (QVNNs) via the periodically intermittent feedback control is studied. Firstly, the finite-time synchronization problem is presented for the first time via the periodically intermittent control approach. Secondly, the upper bounds of the settling time for finite-time synchronization are estimated. Thirdly, a kind of novel controller, state feedback controller, which contains an integral term and delayed term, is proposed. Through these, the problem of finite-time synchronization has been solved very well. Finally, several new conditions ensuring finite-time synchronization of two delayed QVNNs are derived by establishing a new differential inequality and constructing a Lyapunov function. In the end, two numerical examples with simulations show the effectiveness of the derived results and the developed method.

The settling performance design of operational amplifiers is an important issue in discrete-time system applications. Most of the currently existing approaches achieve settling time-oriented design based on an approximate analytical transfer function model, and the result is inaccurate. A method for the exact settling performance-driven design of three-stage nested-Miller-compensated CMOS amplifiers is proposed in this paper. With the user-specified settling time at a certain accuracy level, this method finds the optimal solution by a two-step strategy, where the parameters of the compensation network are first solved from the equations formulated based on the minimal settling condition, and then the transconductance of the last stage is adjusted automatically according to the targeted settling time. The accuracy of the method is guaranteed by the use of the SPICE simulation of the settling waveform in the entire procedure. When the process variations are considered, an accurate worst-case design method is further developed. The method also features high efficiency compared with conventional optimization-based approaches. Experimental results of the simulated design in a 90 nm technology are provided to validate the effectiveness of the method.

This study develops two new indices in structural optimization to minimize peak response and settling time of free vibration, respectively. The two new indices are developed by substituting weight functions into a classic quadratic integral index. With the weight functions, the contributions of structural responses in different time intervals to the value of performance index can be adjusted according to requirements. In such a way, the new indices can approximately evaluate structural performances in reduction of the peak response and settling time, respectively. The new indices have the advantages that they retain the benefits of the classical index for the ease of numerical calculation and sensitivity analysis. Furthermore, they are easy to implement by slightly modifying various developed optimization approaches. Finally, four numerical examples are considered. The proposed two new indices show good performance in reducing the peak response and settling time of free vibration.

Purpose: The development of new contact lens materials and designs are necessary to minimise patient dropout. A lens material with water surface technology was recently developed to incorporate toric design. The on-eye stability of a toric contact lens is critical to a successful toric lens fitting. In an effort to establish if the new daily disposable verofilcon A toric silicone hydrogel lens provides fast stability for ease of fit, this study assessed the initial and short-term on-eye stability of this new lens. Patients and Methods: Habitual full-time wearers of soft contact lenses, aged 18 or over, were enrolled and fit with the verofilcon A toric lens. Study endpoints included lens settling time, axis orientation at specific time-points within 10 minutes after insertion, lens oscillation with blink, lens movement and centration, and scribe mark visibility. Results: Thirty-nine subjects completed the study; 67% were female and mean age was 34.1 [+ or -] 10.8 years (range 18 to 61). The majority of verofilcon A toric lenses (98.7%) settled on average within 60 seconds. Average lens orientation was 3[degrees] from six o'clock position within two minutes of insertion. The lenses showed minimal oscillation with blink; 98.7% of the eyes demonstrated [less than or equal to] 5[degrees] oscillation with blink. All lenses showed optimal/acceptable lens movement and centration and the scribe mark was reported as easily visible in 96% of eyes. Practitioners reported a 99% first lens fit success rate. Conclusion: The novel verofilcon A toric lens was highly successful with the first lens, had excellent on-eye stability and good fit characteristics. These qualities make this new lens a good option for lens wearers. Furthermore, it fulfills the needs of practitioners who want a toric lens that is easy and predictable to fit. Keywords: verofilcon A, easy to fit, settling time, orientation, surface technology

In this paper, we emphasize on a novel fast fixed-time control strategy and its application to fixed-time synchronization control of semi-Markov jump delayed Cohen-Grossberg neural networks (SMJDCGNNs). First, we consider a class of SMJDCGNNs. Second, a novel fast fixed-time control strategy is proposed and designed to control the considered delayed system to achieve global synchronization within the derived fixed settling time. Third, the advantages of the derived theoretical results are discussed. Finally, we give a numerical example to show the effectiveness and feasibility of the obtained theoretical results.

A hydraulic retention time (HRT) of 4, 6, and 8 h was employed, respectively, in three reactors to study the effects of HRT on granulation with a newly developed fast granulation strategy, i.e., a strategy by combining strong hydraulic selection pressure with high organic loading rate (OLR). Granules with clear boundary appeared within 24 h after reactor start-up and all reactors reached a pseudo steady state after 6-day operation. A 4-h HRT resulted in a relatively higher increasing rate in terms of granule size during granule development period, i.e., 208 μm day⁻¹, and the bigger granule size and the higher sludge volume index at the pseudo steady state. For HRT of 6 or 8 h, no obvious difference was observed. However, it was found that HRT influenced sludge retention time (SRT) and kinetics significantly. A HRT changing from 4 to 8 h led to an increased SRT from 3 to 21 days, a decreased observed specific biomass growth rate (μ ₒbₛ) and an decreased observed biomass yield (Y ₒbₛ) of stable granules from 0.37 to 0.062 days⁻¹, and 0.177 to 0.055 g MLVSS g⁻¹ COD, respectively. Both μ ₒbₛ and Y ₒbₛ had a linear relationship with the reciprocal of HRT. In addition, the great difference of microbial community between seed sludge, sludge retained in the reactors, and sludge washed out indicated a strong microbial selection for fast granulation within 24 h. However, during the granule development period from day 1 to 6, no more microbial selection was observed except an adjustment of microbial community. Little influence of HRT on microbial population in granular sludge indicated a minor role of HRT played for granulation with the fast start-up strategy adopted in this study. The results demonstrated that hydraulic selection pressure for granulation was mainly from short settling time, which led to strong microbial selection during the granulation period. Meanwhile, although HRT did not affect granulation with the fast start-up strategy, it played an important role on sludge retention time and excess sludge production. Therefore, HRT should be carefully optimized to balance benefits and shortfalls it brings to aerobic granular sludge system.

This work investigates the finite-time stability (FTS) issue for a class of inertial neural networks (INNs) with mixed-state time-varying delays, proposing a novel analytical approach. Firstly, we establish a novel FTS lemma, which is entirely different from the existing FTS theorems, and extend the current research results. Secondly, an improved discontinuous reliable control mechanism is developed, which is more valid and widens the application scope compared to previous results. Then, by using a novel non-reduced order approach (NROA) and the Lyapunov functional theory, novel sufficient criteria are established using FTS theorems to estimate the settling time with respect to a finite-time stabilization of INNs. Finally, the simulation results are given to validate the usefulness of the theoretical results.

The heuristic perturb-and-observe-based maximum-power-point tracking (MPPT) algorithm of photovoltaic (PV) generator is still the most popular technique in use, despite the broad spectrum of developed other MPPT algorithms. The correct direction of the next perturbation step requires that the previous perturbation is settled down properly and the applied perturbation step size is large enough to overcome the PV-power changes induced by the varying irradiation level and/or the power-grid-originated PV-voltage ripple. The requirements for the minimum perturbation step size are well defined in the available literature. The design equations to predict the PV-power settling time are derived by assuming that the PV-interfacing converter operates in continuous conduction mode (CCM). A large perturbation step size may drive the interfacing converter to enter into discontinuous conduction mode (DCM), which will delay the PV-power settling process and destroy the validity of the predicted settling times. In order to avoid confusing the MPPT process, the maximum perturbation step size has to be limited as well. This paper provides theoretical foundations for the proper design of the maximum step size based on the DC-DC interfacing-converter dynamic behavior. The theoretical findings are validated with experiments as well as by simulations by means of a boost-type DC-DC converter and real PV panel.