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In this paper, with the development of an intelligent power system idea, sustainable energy sources were increasingly deployed, including transmission and distribution systems networks. As a result, optimal use of cascaded H-bridge inverter topologies (MLIs) and power distribution operations is critical for long-term power generation. Traditionally, selective harmonics reduction models must be performed to achieve the optimal switching frequency of multilevel inverters. This research aims to determine the switching frequency for wind-incorporated multilevel inverters to reduce overall harmonic components used in grid applications. This research adds towards the best possible solution by employing multiple newly established adaptive optimization techniques: MNSGA-II and salp swarm. The well-known genetic algorithm and particle swarm optimization are used for the wind-tied multilevel inverters optimization issue. Sevenlevel, eleven-level, and fifteen-level MLIs were employed to reduce overall harmonic distortion. The reliability and convergence rate of simulated data with various modulation indices for seven-, eleven-, and fifteen-level MLIs are obtained and compared. Models are developed based on MATLAB Simulink and are used to validate quantitative measurements. [ABSTRACT FROM AUTHOR]

This article proposes a dual space vector PWM control technique for a three-phase to fivephase quasi Z-source direct matrix converter (QZSDMC). The proposed circuit consists of a quasi-impedance source network along with a five-phase traditional matrix converter. With the observation of bidirectional operating capability and the utilization of shoot-through duty ratio, the proposed converter can ensure both buck and boost operations. This converter overcomes the voltage transfer ratio restriction and poor voltage regulation of the traditional matrix converter. Also, this converter ensures continuous input current with an absence of input LC filter components. The proposed direct AC to AC power converter gives an alternate solution to the multiphase drive system instead of the traditional voltage source inverter. The developed dual space vector PWM control technique for three-phase to five-phase voltage conversion is derived from the basic space vector PWM approach. The proposed dual space vector PWM technique utilizes 90 active states and 3 zero vector states among 243 switching states. The QZSDMC has been analysed with a dual space vector PWM approach along with the distribution of shootthrough state in the zero vector. The proposed topology along with the control strategy has been simulated using MATLAB/Simulink environment. [ABSTRACT FROM AUTHOR]

Objective: We assessed the diagnostic utility of the occurrence rate of high-frequency oscillations and modulation index (MI) from intraoperative electrocorticography (ioECoG) in determining the extent of epileptogenicity in mesial temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS).Methods: We enrolled 17 patients who underwent selective amygdalohippocampectomy (SelAH) for TLE due to HS. We analyzed the occurrence rate of ripples (80-200 Hz) and fast ripples (200-300 Hz); and MI between ripples and 3-4 Hz (MIRipples/3-4 Hz) and fast ripples and 3-4 Hz (MIFRs/3-4 Hz) from the amygdala, hippocampus, and lateral temporal lobe (LTL) pre-SelAH and the LTL post-SelAH, and subsequently categorized the patients into good and poor seizure outcome groups. We compared the occurrence rates and MIs over each region of interest between both groups. Receiver operating characteristic analysis was used to identify the most optimal indicator to predict poor surgical outcomes.Results: In the poor seizure outcome group, an increase in the occurrence rate of ripples was seen in the hippocampus and LTL pre-SelAH and the LTL post-SelAH. The MIRipples/3-4 Hz from the LTL pre-SelAH was the most indicative factor of poor outcome.Conclusions: High occurrence rate of ripples and MIRipples/3-4 Hz from the LTL showed wide epileptogenicity in TLE patients with poor seizure outcomes after SelAH. Our data suggest that the analysis of the occurrence rate of HFOs and MIHFOs/3-4 Hz from ioECoG, especially from the LTL, can indicate the distribution of epileptogenicity in TLE with HS. [ABSTRACT FROM AUTHOR]

Stringent environmental regulations and increasing oil prices showcase the need for renewable energy sources like solar in marine transportation. The application of solar energy in electric propulsion systems is growing tremendously. Power electronics-based inverters help in harvesting direct current (DC) power into alternating current (AC) power. A multilevel inverter (MLI) is a popular power electronic converter producing the desired output voltage from several DC input voltage sources like batteries, supercapacitors, and solar panels. An MLI consists of several switches whose action results in severe harmonic issues. Specific harmonic elimination in MLI is a challenging job and is resolved conventionally by the Newton-Raphson method. However, nowadays, soft computing techniques are used to solve nonlinear equations optimally. In this manuscript, minimization of total harmonic distortion in MLI has been taken as an optimization problem and is solved using teaching-learning–based optimization (TLBO). The TLBO algorithm is applied to compute the optimum switching angles for MLI to produce the required fundamental output voltage with less harmonic distortion. As it does not require any algorithm-specific parameters, TLBO is an effective method to obtain optimum MLI solutions. A 21-level symmetric MLI is simulated and is used to evaluate the performance of the TLBO algorithm. The simulation results are validated using an experimental model of proposed MLI with a Xilinx Spartan-SA field programmable gate array–based controller. This research outcome bears testimony to TLBO optimization’s efficiency in improving the quality of the power generated in ships using renewable sources. [ABSTRACT FROM AUTHOR]

Purpose: The removal of the bottom of sulcus dysplasia (BOSD) often includes the gyral crown; however, this method has been controversial. We hypothesized that the epileptogenic zone of the BOSD does not include the gyral crown. To reveal the depth and extent of the epileptogenic zone of the BOSD, we applied the two electrophysiological modalities: (1) the occurrence rate (OR) of high-frequency oscillations (HFOs) and (2) modulation index (MI), reflecting the strength of phase-amplitude coupling between HFOs and slow oscillations.Methods: We investigated the ripples [80-200 Hz] and fast ripples [200-300 Hz]) in HFOs and MI (HFOs [80-300 Hz] and slow oscillations [3-4 Hz]). We opened the sulcus at the BOSD and implanted the subdural electrodes directly over the MRI visible lesion. All patients (n = 3) underwent lesionectomy and the gyral crown was preserved.Results: Pathological findings demonstrated focal cortical dysplasia type IIb and seizure freedom was achieved. The OR of the HFOs was not significantly different between the BOSD and the gyral crown. In contrast, the MI between HFOs and slow oscillations in the BOSD was significantly higher than that in the gyral crown.Conclusion: High MI values distinguished the epileptogenic BOSD from the non-epileptogenic gyral crowns. MI could be a more informative biomarker of epileptogenicity than the OR of HFOs in a subset of patients with the BOSD. [ABSTRACT FROM AUTHOR]

Highlights • Texture analysis on fluence maps of IMRT plans. • Evaluating the plan delivery accuracy. • Correlation between textural features and IMRT delivery accuracy. • Textural features could be used as a support tool to verify IMRT delivery accuracy. Abstract Purpose The aim of this study is to evaluate the plan delivery accuracy of intensity-modulated radiation therapy (IMRT) by using textural features calculated from fluence maps. Methods In total, 202 IMRT plans were generated with the Trilogy (C-series linac) and TrueBeam STx systems. Fluence maps were obtained for each IMRT plan. With the fluence map, six textural features were calculated, namely angular second moment (ASM) , inverse difference moment (IDM) , contrast , variance , correlation , and entropy (particular displacement distances, d = 1, 5, and 10). To evaluate performances of textural features in predicting IMRT delivery accuracy, Spearman's rank correlation coefficients (r s) were calculated between textural feature values and measures of conventional methods. Results For Trilogy, correlation (d = 1) showed r s values of −0.764 (p < 0.001) with gamma passing rates of 2%/1 mm and 0.863 (p < 0.001) with multi-leaf collimator (MLC) errors. For TrueBeam STx, variance (d = 10) showed r s values of 0.691 (p < 0.001) with gamma passing rates of 1%/2 mm and −0.585 (p < 0.001) with MLC errors. Conclusion Correlation (d = 1) for Trilogy and variance (d = 10) for TrueBeam STx demonstrated the potential in predicting IMRT delivery accuracy with high correlations to conventional IMRT delivery accuracy measures. [ABSTRACT FROM AUTHOR]

Pulse Width Modulation (PWM) inverters play a major role in the field of power electronics. Space Vector Modulated PWM (SVPWM) is the popular PWM method and possibly the best among all the PWM techniques as it generates higher voltages with low total harmonic distortion and works very well with field oriented (vector control) schemes for motor control. High quality output spectra can be obtained by eliminating several low order harmonics by adopting a suitable harmonic elimination technique. In this paper, a mathematical model of space vector modulated three phase inverter is formulated and an offline method for generation of Harmonic Eliminated PWM (HEPWM) by eliminating the low order harmonics of the output waveform is prepared. A systematic online method based on Curve Fitting Technique (CFT) and modification of SVPWM output waveform to a harmonic eliminated waveform is developed for practical implementation. The harmonic spectrum analysis of the proposed model is carried out to ensure the effectiveness. The correctness of the proposed online method is verified by comparing the simulation results with the offline method. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a new non prior knowledge estimator of the modulation index of angle modulated (AM) signals is proposed. It consists in estimating jointly the frequency modulation index and the phase modulation index. It is based on the observation that both the baseband modulation types have the similar time-frequency(TF) structure. The practical implementation of this estimator is described and the asymptotic behavior of the estimation error is studied. If N is the number of signaling intervals, the estimate of the modulation index is shown to converge to a non- Gaussian distribution at rate 1/N. Simulations results sustain our theoretical claims. [Copyright &y& Elsevier]