bluuebunny/crossref_metadata_2025 huggingface dataset:
Second generation laryngeal mask airway during laparoscopic living liver donor hepatectomy: a randomized controlled trial
Authors: Kim Doyeon , Park Sukhee , Kim Jong Man , Choi Gyu Seong , Kim Gaab Soo
Published: February 2021

The second-generation laryngeal mask airway (LMA) provides a higher sealing pressure than classical LMA and can insert the gastric drainage tube. We investigated the difference in respiratory variables according to the use of second-generation LMA and endotracheal tube (ETT) in laparoscopic living liver donor hepatectomy (LLDH). In this single-blind randomized controlled trial, intraoperative arterial carbon dioxide partial pressure at 2 h after the airway devices insertion (PaCO2_2h) was compared as a primary outcome. Participants were randomly assigned to the following groups: Group LMA (n = 45, used Protector LMA), or Group ETT (n = 43, used cuffed ETT). Intraoperative hemodynamic and respiratory variables including mean blood pressure (MBP), heart rate (HR), and peak inspiratory pressure (PIP) were compared. Postoperative sore throat, hoarseness, postoperative nausea and vomiting (PONV), and pulmonary aspiration were recorded. The PaCO2_2h were equally effective between two groups (mean difference: 0.99 mmHg, P = 0.003; 90% confidence limits: − 0.22, 2.19). The intraoperative change in MBP, HR, and PIP were differed over time between two groups (P < 0.001, P = 0.015, and P = 0.039, respectively). There were no differences of the incidence of postoperative complications at 24 h following LLDH (sore throat and hoarseness: P > 0.99, PONV: P > 0.99, and P = 0.65, respectively). No case showed pulmonary aspiration in both groups. Compared with endotracheal tube, second-generation LMA is equally efficient during LLDH. The second-generation LMA can be considered as the effective airway devices for securing airway in patients undergoing prolonged laparoscopic surgery.

Trial Registration This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CRiS No. KCT0003711).
Optimizing livestock carrying capacity for wild ungulate-livestock coexistence in a Qinghai-Tibet Plateau grassland
Authors: Ren Yueheng , Zhu Yanpeng , Baldan Davide , Fu Mengdi , Wang Bin , Li Junsheng , Chen Anping
Published: February 2021

Wild ungulates are an important part of terrestrial ecosystems and play a critical role in maintaining ecosystem health and integrity. In many grassland ecosystems that are habituated by wild ungulates, the coexistence of domestic ungulates has created a conflict over grazing resources. Solving this conflict requires a balanced and sustainable policy that satisfies both the needs of wildlife protection and food production. Here, we assess the optimal grassland livestock carrying capacity of an alpine grassland on the Qinghai-Tibet Plateau, given the coexistence of wild populations of kiangs (Equus kiang) and Tibetan gazelles (Procapra picticaudata), two key species grazing in this region. We use kriging and the MaxEnt method to estimate the population sizes of kiangs and Tibetan gazelles in Maduo County, Qinghai Province. We then convert the estimated population size of the two species into sheep units and calculate the residual carrying capacity for livestock grazing. We show that after accounting for the grazing need for kiangs and Tibetan gazelles, grassland in Maduo is capable of supporting 420,641 sheep units, which is slightly more than the current livestock population. However, the residual carrying capacity is highly uneven across the region, and overgrazing is found in many areas of Maduo, especially in northern Maduo. This research provides a useful framework for planning sustainable livestock farming for the Qinghai-Tibet Plateau and other regions facing wildlife-livestock conflict.
A retrospective study of hypofractionated radiotherapy for keloids in 100 cases
Authors: Wen Ping , Wang Taifang , Zhou Yueling , Yu Yue , Wu Chunli
Published: February 2021

At present, the consensus on the best treatment for keloids is the combination of clinical and surgical therapies, if necessary, associated with adjuvant radiotherapy like brachytherapy. Whereas, the uniform scheme of radiotherapy in keloids is unclear. Here, we conducting a retrospective analysis to assess the efficacy and safety of a specific treatment regimen (20 Gy in 5 fractions) in keloid patients. We retrospectively analysed the medical records of keloid patients receiving auxiliary postoperative radiotherapy (PORT) treatment from 2009 to 2019. The patients were treated with the hypofractionation method of 20 Gy in 5 fractions. We compared the local control rate and complications, using the chi-square test and logistic regression analyses. After screening, we identified 100 keloid patients in this study, with a median follow-up of 59 months. In this study, the overall local control rate of keloid lesions was 84.8%. After multivariate analyses (primary keloid or not, family history, interval from surgery to irradiation and site), our research showed that primary keloid, site and interval from surgery to irradiation were significantly related to recurrence. Acute radiation injury and late radiation injury accounted for 3% (erythema) and 1% (skin sclerosis) of the total cases, respectively. Our results indicate that a postoperative hypofractionation with radiation dose of 20 Gy in 5 fractions may be effective, easy to accept and safe for keloid patients.
Transcriptomic and proteomic analysis of Hemidactylus frenatus during initial stages of tail regeneration
Authors: Nagumantri Sai Pawan , Banu Sarena , Idris Mohammed M.
Published: February 2021

Epimorphic regeneration of appendages is a complex and complete phenomenon found in selected animals. Hemidactylus frenatus, house gecko has the remarkable ability to regenerate the tail tissue upon autotomy involving epimorphic regeneration mechanism. This study has identified and evaluated the molecular changes at gene and protein level during the initial stages, i.e., during the wound healing and repair mechanism initiation stage of tail regeneration. Based on next generation transcriptomics and De novo analysis the transcriptome library of the gecko tail tissue was generated. A total of 254 genes and 128 proteins were found to be associated with the regeneration of gecko tail tissue upon amputation at 1, 2 and 5-day post amputation (dpa) against control, 0-dpa through differential transcriptomic and proteomic analysis. To authenticate the expression analysis, 50 genes were further validated involving RTPCR. 327 genes/proteins identified and mapped from the study showed association for Protein kinase A signaling, Telomerase BAG2 signaling, paxillin signaling, VEGF signaling network pathways based on network pathway analysis. This study empanelled list of transcriptome, proteome and the list of genes/proteins associated with the tail regeneration.
The study of the influence of pH on the structural and spectroscopic properties of nanocrystalline Eu3+ ion-doped yttrium orthovanadate
Authors: Wujczyk Marta , Watras Adam , Wiglusz Rafal J.
Published: February 2021

In this study, it has been presented the influence of pH conditions on the evolution of the size and morphology of yttrium orthovanadate during synthesis.
The elevated colour rendering of white-LEDs by microwave-synthesized red-emitting (Li, Mg)3RbGe8O18:Mn4+ nanophosphors
Authors: Abraham Malini , Kunti Arup K. , K.K. Thejas , Amador-Mendez Nuño , Gogneau Noëlle , K.G. Nishanth , Tchernycheva Maria , Das Subrata
Published: February 2021

The bright red emitting (Li, Mg)3RbGe8O18:Mn4+ nanophosphors significantly enhanced the colour rendering of a white-LED based on blue-LED chip and YAG:Ce3+ phosphor.
In situpolymerization process: an essential design tool for lithium polymer batteries
Authors: Vijayakumar Vidyanand , Anothumakkool Bihag , Kurungot Sreekumar , Winter Martin , Nair Jijeesh Ravi
Published: February 2021

A comprehensive review article addressing the prospects of thein situpolymerization strategy as a tool for surpassing the challenges of electrode|electrolyte interfaces & interphases in lithium polymer batteries.
Enhanced oxygen evolution catalytic activity of NiS2 by coupling with ferrous phosphite and phosphide
Authors: Yu Jie , Zhang Tao , Xing Changchang , Li Xuejiao , Li Xinyang , Wu Bo , Li Yue
Published: February 2021

NiS2/Fe-P nanospheres were developed as an efficient oxygen evolution reaction electrocatalyst with a low overpotential (218 mV @ 10 mA cm−2 and 306 mV @ 800 mA cm−2) and Tafel slope (47.5 mV dec−1).
Correction: Injectable postoperative enzyme-responsive hydrogels for reversing temozolomide resistance and reducing local recurrence after glioma operation
Authors: Zhao Zongren , Shen Jiawei , Zhang Long , Wang Lansheng , Xu Haoyue , Han Yuhan , Jia Jun , Lu Yang , Yu Rutong , Liu Hongmei
Published: February 2021

Correction for ‘Injectable postoperative enzyme-responsive hydrogels for reversing temozolomide resistance and reducing local recurrence after glioma operation’ by Zongren Zhao et al., Biomater. Sci., 2020, 8, 5306–5316, DOI: 10.1039/D0BM00338G.
Controlled di-lithiation enabled synthesis of phosphine-sulfonamide ligands and implications in ethylene oligomerization
Authors: Mote Nilesh R. , Gaikwad Shahaji R. , Khopade Kishor V. , Gonnade Rajesh G. , Chikkali Samir H.
Published: February 2021

Arresting dilithiation intermediate at −84/−41 °C selectively produced L1A/L1B and L2A/L2B, respectively, from a single precursor. Pd-Complexes C1–C7 were prepared, fully characterized and their performance in ethylene oligomerization was studied.
Palladium(ii)-assisted activation of thioglycosides
Authors: Escopy Samira , Singh Yashapal , Demchenko Alexei V.
Published: February 2021

Described herein is the first example of glycosidation of thioglycosides in the presence of palladium(ii) bromide.
Correction: Complexing agent study via computational chemistry for environmentally friendly silver electrodeposition and the application of a silver deposit
Authors: Liu Anmin , Ren Xuefeng , Wang Bo , Zhang Jie , Yang Peixia , Zhang Jinqiu , An Maozhong
Published: February 2021

Correction for ‘Complexing agent study via computational chemistry for environmentally friendly silver electrodeposition and the application of a silver deposit’ by Anmin Liu et al., RSC Adv., 2014, 4, 40930–40940, DOI: 10.1039/C4RA05869K.
Continuously efficient hydrodeoxygenation of glycerol into 1,3-propanediol over Pt/WOx/beta catalysts
Authors: Zhu Lijun , Sun Mengya , Zhao Xinpeng , Zhang Yanfei , Luo Hu , Liu Wang , Miao Gai , Kong Lingzhao
Published: February 2021

Continuous hydrodeoxygenation of glycerol into 1,3-PDO for over 600 h was attributed to the highly dispersed metals without aggregation on a Pt/WOx/beta catalyst.
Phonetic Effects in Child and Adult Word Segmentation
Authors: Katz Jonah , Moore Michelle W.
Published: February 2021

Purpose

The aim of the study was to investigate the effects of specific acoustic patterns on word learning and segmentation in 8- to 11-year-old children and in college students.

Method

Twenty-two children (ages 8;2–11;4 [years;months]) and 36 college students listened to synthesized “utterances” in artificial languages consisting of six iterated “words,” which followed either a phonetically natural lenition–fortition pattern or an unnatural (cross-linguistically unattested) antilenition pattern. A two-alternative forced-choice task tested whether they could discriminate between occurring and nonoccurring sequences. Participants were exposed to both languages, counterbalanced for order across subjects, in sessions spaced at least 1 month apart.

Results

Children showed little evidence for learning in either the phonetically natural or unnatural condition nor evidence of differences in learning across the two conditions. Adults showed the predicted (and previously attested) interaction between learning and phonetic condition: The phonetically natural language was learned better. The adults also showed a strong effect of session: Subjects performed much worse during the second session than the first.

Conclusions

School-age children not only failed to demonstrate the phonetic asymmetry demonstrated by adults in previous studies but also failed to show strong evidence for any learning at all. The fact that the phonetic asymmetry (and general learning effect) was replicated with adults suggests that the child result is not due to inadequate stimuli or procedures. The strong carryover effect for adults also suggests that they retain knowledge about the sound patterns of an artificial language for over a month, longer than has been reported in laboratory studies of purely phonetic/phonological learning.

Supplemental Material

https://doi.org/10.23641/asha.13641284
Neuro‐adaptive fixed‐time trajectory tracking control for human‐in‐the‐loop teleoperation with mixed communication delays
Authors: Xu Jing‐Zhe , Ge Ming‐Feng , Ding Teng‐Fei , Liang Chang‐Duo , Liu Zhi‐Wei
Published: February 2021

The fixed‐time master–slave trajectory tracking control problem of the human‐in‐the‐loop teleoperation systems with mixed communication delays (including time‐varying delays and random delays), parametric uncertainties, and external disturbances is discussed in this study. Based on the non‐singular terminal sliding mode control technique, a novel neuro‐adaptive fixed‐time control algorithm is designed to solve the above‐mentioned problem. Moreover, to improve the steady‐state performance of the presented control algorithm, the combination of the radial basis function neural networks, parametric adaptive laws and fixed‐time control method is newly‐designed and used to reduce the effects of parametric uncertainties and external disturbances. By employing the Lyapunov argument, the sufficient conditions on the control parameters for guaranteeing the fixed‐time stability of the controlled teleoperation system are derived. Besides, the authors also present the upper bound of the settling time and prove that it is independent of the initial condition. Finally, several simulation examples are performed to verify the effectiveness of the theoretical results.
Observer‐based distributed hybrid‐triggered H∞ control for sensor networked systems with input quantisation
Authors: Tan Yushun , Li Qing , Du Dongsheng , Niu Ben , Fei Shumin
Published: February 2021

In this technical note, the problem of observer‐based controller design is considered for sensor networked systems subject to distributed hybrid‐triggered transmission scheme and input quantisation. A novel observer model based on coupled transmission signals from multi‐channel is first proposed to estimate unavailable state variables and exploited in the feedback protocol. In order to provide a trade‐off between saving network resources and improving system performance, a distributed hybrid‐triggered transmission scheme with communication delays is adopted to update the observer input signals. For the sake of further reducing the occupancy of network resources, the control input signal is quantised by a logarithmic quantiser. Then, by making use of the Lyapunov stability theory, the sufficient conditions guaranteeing the system asymptotically stable are presented. Moreover, the explicit expressions of observer and controller parameters are achieved by solving a set of linear matrix inequalities. Finally, two simulation examples are provided to illustrate the rationality of the proposed control method.
Bipartite containment of descriptor multi‐agent systems via an observer‐based approach
Authors: Han Tao , Xiao Bo , Zhan Xi‐Sheng , Yan Huaicheng
Published: February 2021

This study considers the bipartite containment problem for a class of descriptor multi‐agent systems (MASs) under a structurally balanced graph. A new bipartite containment control protocol acting on each follower is proposed on the basis of designing a singular observer, where relative output information is utilised. By employing the stability theory of descriptor systems and multiple Lyapunov function technique, some sufficient criteria are derived to guarantee observer‐based bipartite containment of descriptor MASs. The feasibility of obtained theoretical results is finally verified via performing simulations.
Geometric‐based PID control design with selective harmonic mitigation for DC–DC converters by imposing a norm bound on the sensitivity function
Authors: Magossi Rafael F.Q. , Han Sangjin , Machado Ricardo Q. , Oliveira Vilma A. , Bhattacharyya Shankar P.
Published: February 2021

The DC–DC converters usually interfaces renewable energy sources in DC microgrids which may be contaminated by harmonic perturbations that adversely affect performance, creates stability and protection problems in a DC grid system. In this paper, the authors propose the use of the popular proportional–integral–derivative (PID) controller to mitigate selected harmonics. The solution is obtained by computing the complete set of stabilising controllers and imposing a bound on the sensitivity function. Using matrix representation of conic sections, the geometric‐based PID controller is derived in the controller parameter space. The main result finds a subset of the stabilising set in which the controller mitigate harmonics with prescribed levels of attenuation which are constructively determined for each frequency of the selected harmonics. Simulation and experimental results using a boost converter are provided for validation.
Parameter estimation for a multi‐input multi‐output state‐space system with unmeasurable states through the data filtering technique
Authors: Cui Ting , Ding Feng , Sheng Jie
Published: February 2021

Parameter estimation is an important tool for modelling a real system. This study considers the parameter estimation problem of a multi‐input multi‐output state‐space system with unmeasurable states. By employing the negative gradient search and cutting down redundant parameter estimates, the authors derive a partially‐coupled generalised stochastic gradient (PC‐GSG) algorithm to estimate the parameters. Considering the unmeasurable states, they present a new state observer which replaces the unknown parameters with their estimates to generate state estimates. By combining the PC‐GSG algorithm and the new state observer, they obtain a state observer based partially‐coupled generalised stochastic gradient (SO‐PC‐GSG) algorithm to estimate the parameters and states. In order to eliminate the interference of the coloured noise and strengthen the performance of the SO‐PC‐GSG algorithm, they propose a state observer based filtering PC‐GSG algorithm by means of the data filtering technique. Finally, the effectiveness of the proposed algorithms is investigated in a simulation study.
High efficiency power extraction control method for direct‐drive linear wave energy converters based on forced resonance
Authors: Huang Xuanrui , Xiao Xi
Published: February 2021

It is commonly acknowledged that a direct‐drive linear wave energy converter (DDLWEC) will achieve maximum power extraction in the resonance state, which can be realised through impedance matching under the assumption that the wave is regular. While the real ocean waves are hardly regular. Considering swell, a relatively regular type of real ocean wave, by approximating it with a sum of multiple frequency components, the DDLWEC can be forced resonance to the swell through velocity control, the optimal velocity is derived based on the dynamical model of the DDLWEC through frequency domain analysis. The stability of velocity control is proven and the float equilibrium position deviation due to the velocity control is analysed and countered through compensation control. In real‐time control, the excitation force is approximated by the sum of four sinusoids, simulation and experiment results demonstrate that the proposed method is valid, stable, capable of achieving a high‐power extraction efficiency, and superior to some existing methods.
Simple current control of permanent magnet synchronous machines for railway traction operating in six‐steps
Authors: Fang Xiaochun , Tian Zhongbei , Yang Zhongping , Lin Fei , Tricoli Pietro
Published: February 2021

Due to the voltage limitation of the inverter DC‐link of railway traction systems, six‐step operations are widely used in the high‐speed region to improve the voltage utilization and increase the maximum fundamental frequency. The magnitude of the output voltage fundamental harmonic reaches the maximum for six‐step operations, while only the phase angle can be adjusted. This limitation makes it challenging to control the instantaneous current of permanent magnet synchronous motors (PMSM). This paper proposes a single d‐axis current regulator flux‐weakening control scheme to improve the current control over six‐step operations of PMSM without changing the inverter output voltage modulation ratio by controlling only one degree of freedom. The voltage in six‐step operations is generated by synchronous space vector pulse width modulation based on basic bus clamping strategy with an effective limitation of the switching frequency in the full‐speed region. A simplified model of the current regulator is developed for the analysis and design of the controller parameters. This paper presents clear rules for entering and quitting six‐step operations effectively to achieve a smooth transition between double current regulators and the single current regulator control. The numerical results are verified by experimental measurements on a 7.5 kW PMSM drive.
Multi‐loop model for fractional pole‐path ratio synchronous generators with stator winding internal faults
Authors: Xiao Shiyong , Ge Baojun , Liu Zhihui , Tao Dajun
Published: February 2021

Fractional pole‐ratio winding is a new type of AC winding, consisting of coils with different pitches. The application of fractional pole‐path ratio windings in synchronous generators will bring new problems to the modelling and simulation of internal faults. It is important to establish a mathematical model for the fractional pole‐path ratio synchronous generators with internal faults and accurately calculate the fault currents. In this study, the multi‐loop model of fractional pole‐path ratio synchronous generators is first proposed. The method for calculating mutual inductances between stator coils with arbitrary pitch is given, and all the space harmonics, including the fractional ones, are considered in the inductance calculation. In order to improve the simulation accuracy of turn‐to‐turn faults, the effect of core localised saturation is modelled by modifying the air gap function of fault coils. A 300 MW fractional pole‐path ratio synchronous generator is set as an example, and three types of internal faults are simulated. The comparisons of simulation results are made between the multi‐loop model and the finite element model to verify the validity of the multi‐loop model proposed in this study.
Crossed flat solenoid coupler for stationary electric vehicle wireless charging featuring high misalignment tolerance
Authors: Yao Yousu , Tang Chengxiong , Wang Yijie
Published: February 2021

This study proposes a crossed flat solenoid coupler (CFSC) for electric vehicle wireless charging. The impact of four size parameters of CFSCs on coupling coefficient and misalignment tolerance is studied using finite‐element analysis. The optimisation methodology of CFSCs considering size constraints is given. The CFSC is compared with the planar square coupler (PSC) and double D coupler (DDC) from three aspects: coupling coefficient, misalignment tolerance, and copper usage. The CFSC performs the best in the three aspects, and the DDC performs the worst. Two wireless power transfer prototypes, one employing CFSCs and the other utilising PSCs, were built to demonstrate the superiority of the proposed coupler. Primary inductor‐capacitor‐capacitor secondary series compensation topologies were employed in the two prototypes. Experiments agree well with theoretical analysis and simulations. The power transfer efficiency of the CFSC‐based prototype was 1.6% higher than the PSC‐based prototype when the Z‐axis displacement is 45 mm.
Theory of symmetric winding distributions and a general method for winding MMF harmonic analysis
Authors: Sun Yi , Lin Yingqian , Wang Yunchong , Nilssen Robert , Shen Jian‐Xin
Published: February 2021

One of the main challenges in motor design is the winding layout, including winding distributions and magnetomotive force (MMF) harmonic analysis. Considering some shortcomings in the existing theories for winding distributions and difficulties in dealing with unconventional fractional‐slot windings, a unified theory of symmetric winding distributions is proposed. First, this study gives the sufficient and necessary conditions for a m‐phase symmetric winding and the novel winding distribution formula. Subsequently, a general method for MMF harmonic analysis including the amplitude of MMF harmonics and harmonic orders are proposed. Finally, the analysis results show that this unified theory is an efficient and compact method to deal with the winding layout to analyse all kinds of winding MMF harmonics.
Comparison of PCB winding topologies for axial‐flux permanent magnet synchronous machines
Authors: Tokgöz Furkan , Çakal Gökhan , Keysan Ozan
Published: February 2021

Although axial‐flux permanent magnet machines have high torque densities, challenges regarding mass production of stators make them a less appealing choice. Printed circuit board (PCB) axial‐flux machine is a type of machine with a stator that is made of layers of PCB. Given the precise, fast, and cheap mass production capabilities of PCB manufacturers, PCB axial‐flux machines stand as a viable alternative for conventional round‐wire winding machines. In this study, five different winding topologies are compared. Their induced phase voltages and torque are calculated using the developed magnetic scalar potential method and finite element analysis (FEA). Proposed windings are tested on a 16‐pole, 2000‐RPM, double rotor‐single stator axial‐flux permanent magnet synchronous machine. Results showed that the parallel winding had the smallest resistance and loss. Moreover, radial and concentric winding had the highest induced voltage and torque while the radial winding had 20% less phase resistance than concentric. Also, the induced voltage of radial winding had the smallest total harmonic distortion in comparison with other winding types. A novel unequal width parallel winding is proposed and it is compared with parallel winding separately. It is found that by simply increasing the cross‐section area of wave windings, it is possible to decrease copper loss by 17%.
Multiple parallel‐connected DAB‐based solid‐state transformer for hybrid DC/AC microgrid system
Authors: Nalamati Chandra Sekhar , Agrawal Alok , Gupta Rajesh
Published: February 2021

To cater unceasing supply to the modern AC and DC loads, renewable energy resources integrated hybrid DC/AC microgrid (HMG) are considered as a viable technological solution. In this study, a multiple parallel‐connected bidirectional converter (MPBC) topology has been proposed to enhance the solid‐state transformer (SST) power handling capability with flexible control of the HMG. To improve the high‐frequency AC‐link power quality and to control the power transfer through the SST in each dual active bridge a split‐step phase shift (SSPS) control technique has been used. A power management control strategy has also been proposed for efficient power transfer between the sources and loads of the HMG. The proposed MPBC‐based SST is suitable for interconnecting multiple utility feeders. Multiple redundant utility feeders ensure stiff bus voltages and omit the power supply reliability issues. The operation of the proposed MPBC‐SST converter system with corresponding control algorithm is verified through the simulation results in both grid feeding and grid fetching operating modes. Furthermore, experimental results are presented to validate the performance of the proposed MPBC‐SST converter along with its proposed controller strategy.
Diagnosis of the single phase‐to‐ground fault in distribution network based on feature extraction and transformation from the waveforms
Authors: Shi Fang , Zhang Linlin , Zhang Hengxu , Xu Kai , Vladimir Terzija
Published: February 2021

The increasing permeation of the distributed generators in the power system brings great challenges for fault diagnosis, especially for the distribution networks with ungrounded neutral or grounded by Peterson coil as the fault current is limited and easily affected by the noises and interferences. A single phase‐to‐ground fault section identification method is proposed based on feature extraction of the synchronous waveforms and the calculation of the eigenvalues for the time‐sequenced features. First, several fault features are defined and extracted from the synchronous current waveforms obtained by the fault recorders. Then, the topology related fault feature matrix is constructed using the time‐series features obtained from different measurement sites, and the eigenvalues of the matrix are calculated based on the random matrix theory. Lastly, using the distribution characteristics of the eigenvalues, improved K‐means clustering algorithm is utilised in classifying the fault cases and identifying the faulty sections. The effectiveness of the proposed scheme is verified by IEEE 34 nodes test system and a multi‐feeder distribution network.
Parameter estimation, selective auto‐reclosing and fault location for three‐terminal mixed transmission lines using synchronised data
Authors: Naidu O.D. , George Neethu , Yalla Preetham
Published: February 2021

Considering both environmental and commercial aspects, mixed three‐terminal transmission lines are attractive. Mixed three‐terminal lines consist of two sections of the overhead line and one section of underground cable. In this work, a selective auto‐reclosing, fault location, and parameter estimation technique for mixed three‐terminal lines using synchronised data from all three terminals are proposed. The proposed method uses the pre and during‐fault data recorded at the three ends of the line. Using the recorded sampled data, pre‐fault and during‐fault phasors are estimated. Four functions are formulated from the pre‐fault equivalent network of the system. Additionally, three sets of four functions each are formulated after assuming the fault to be on each of the three sections. Subsequently, the faulted section, fault location, and three sets of line parameters are simultaneously calculated by solving each set of equations. Finally, the correct faulted section, location, and parameters are identified based on the characteristics of obtained line parameters and fault location. Furthermore, the identified faulted section information is applied to enable or block the auto‐reclosing function. The simulations and analysis are carried out using PSCAD/EMTDC and MATLAB scripts, respectively. The accuracy, capabilities, applications, and limitations are discussed for different fault scenarios.
Impact of electricity price forecasting errors on bidding: a price‐taker's perspective
Authors: Zheng Kedi , Wen Bojian , Wang Yi , Chen Qixin
Published: February 2021

Electricity price forecasting is very important for market participants in a deregulated market. However, only a few papers investigated the impact of forecasting errors on the market participants' behaviours and revenues. In this study, a general formulation of bidding in the electricity market is considered and the participant is assumed to be a price‐taker which is general for most of the participants in power markets. A numerical method for quantifying the impact of forecasting errors on the bidding curves and revenues based on multiparametric linear programming is proposed. The forecasted prices are regarded as exogenous parameters for both deterministic and stochastic bidding models. Compared with the existing method, the proposed method can calculate how much improvement will be achieved in the cost or revenue of the bidder if he reduces the price forecasting error level, and such calculation does not require any predefined forecasting results. Numerical results and discussions based on real‐market price data are conducted to show the application of the proposed method.
Configuration strategy of shared mitigation equipment for voltage sag considering the demands of users
Authors: Wang Ying , Yang Yixuan , Xiao Xianyong , Zheng Zixuan , Yang Hang
Published: February 2021

It is an effective way to mitigate voltage sag by equipping custom power devices in premium power park (PPP), and the key lies in the balance between technology and economy. This study proposes a method to mitigate voltage sags to meet the needs of different sensitive users in PPP to ensure the mitigation effect and reduce mitigation costs. Firstly, a strategy of shared mitigation equipment (ME) and its operation mode is presented, including the multiple stakeholders, the structure of shared ME, and the scheme of the switch on/off to improve the utilisation rate of ME. Secondly, a sensitive equipment (SE) grouping method is proposed, which is suitable for shared ME strategy, considering the minimum compensation voltage magnitude and the economic loss caused by voltage sag. Meanwhile, this study proposes an assessment method of SE failure probability based on the three‐parameter Weibull function to design the capacity of ME reasonably. Thirdly, a multi‐objective collaborative optimisation model is established based on economic loss assessment to maximise the net income of investors and users. Finally, the effectiveness of the proposed method has been proved through the case study of two sensitive users in PPP.
Transition characteristics of driver's intentions triggered by emotional evolution in two‐lane urban roads
Authors: Guo Yongqing , Wang Xiaoyuan , Yuan Quan , Liu Shanliang , Liu Shijie
Published: February 2021

Driver's intention is a self‐internal state that represents a commitment to carrying out driving action at the next moment, which could be affected by driver's emotion. Therefore, understanding driver's emotion is an important basis for developing driver intention recognition models. This study aims to gain a better insight of the characteristics of driver intention transition trigged by driver's emotion. The Hidden Markov model was used to develop a driver intention recognition model with the involvement of driver's emotions. Assorted materials including visual, auditory and olfactory stimuli were used to evoke driver's emotions before the driving experiments, as well as keep and increase the emotional level during driving. Real and virtual driving experiments were conducted to collect human‐vehicle‐environment dynamic data in two‐lane roads. The results show that the proposed model can achieve high accuracy and reliability in estimating driver's intention transition with the evolution of driver emotion. Our findings of this study can be used to develop the personalized driving warning system and intelligent human‐machine interaction in vehicles. This study would be of great theoretical significance for improving road traffic safety.
Trajectory prediction for intelligent vehicles using spatial‐attention mechanism
Authors: Yan Jun , Peng Zifeng , Yin Huilin , Wang Jie , Wang Xiao , Shen Yuesong , Stechele Walter , Cremers Daniel
Published: February 2021

It is of great interest for autonomous vehicles to predict the trajectory of other vehicles when planning a safe trajectory. To accurately predict the trajectory of the target vehicle, the interaction between vehicles must be considered. Interaction aware prediction methods track the previous trajectories of both the target vehicle and its surrounding vehicles. In this study, the authors consider trajectory prediction as a sequence‐to‐sequence prediction problem. They tackle this problem with an LSTM encoder–decoder framework. Moreover, they propose two spatial‐attention mechanisms to account for the interaction between vehicles, i.e. context attention and lane attention. Spatial‐attention mechanisms adopt the selective‐attention mechanism of human drivers. They choose context vectors to help the model understand the surrounding environment better and thus improve its prediction accuracy. They evaluate the authors’ methods on the highD data set recorded in German highways with root mean squared error metric. Their experimental results show superior performance to other state‐of‐the‐art methods. Code is available at https://github.com/momo1986/Spatial‐attention.
Predictive kinetic energy management for an add‐on driver assistance eco‐driving of heavy vehicles
Authors: Yoon DoHyun Daniel , Ayalew Beshah , Ivanco Andrej , Loiselle Keith
Published: February 2021

This study presents a radar‐based predictive kinetic energy management (PKEM) framework that is applicable as an add‐on driver assistance module for a heavy vehicle with an internal combustion engine powertrain. The proposed framework attempts to minimise fuel consumption by estimating the motion of the leading vehicle from radar information and optimising the inputs to the ego vehicle in a predictive manner. The PKEM framework consists of a driver‐pedal pre‐filter, an interacting multiple model radar‐based filter and predictor of traffic object states, and a non‐linear model predictive controller. The framework is integrated with established human‐driver car‐following models representing various driving styles and evaluated over a set of standardised driving cycles. The authors found that the energy‐saving benefits can be as much as 23% over the baseline driver‐only case with minimal compromises on travel time in urban environments, while the benefits are nearly negligible on the highway cycle. The results included also show the potential trade‐offs in accommodating driver‐desired inputs.
LightGBM‐based model for metro passenger volume forecasting
Authors: Zhang Youyang , Zhu Changfeng , Wang Qingrong
Published: February 2021

Driven by the era of big data and the development of artificial intelligence, potential traffic patterns can be obtained by analysing the numerous data. Metro has become an essential transport infrastructure and the passenger volume provides the basic support for the optimisation of the metro system. Thus, accurate forecasting of the volume is extremely required. In this study, a model for improving the accuracy and stability of metro passenger volume prediction named VMD‐TPE‐LightGBM (light gradient boosting machine) is proposed. The original dataset is firstly regrouped both in the station and chronological order while the time interval is reset as 10‐minute. Time features for extracting the hidden patterns are extracted by analysing the variation tendency of the passenger volume. For enhancing the precision, the variational mode decomposition algorithm is applied to decompose the original data series. Then each of the modes is regarded as the input of the LightGBM model, which are optimised by a tuning method named the tree of Parzen estimators and K‐fold cross‐validation. According to this process, the final forecasting results are acquired by reconstructing the predicted modes. The experimental results demonstrate that the proposed model performs superior to all the comparisons and has an impressive effect on short‐term metro passenger volume forecasting.
Continuous model predictive control of interleaved boost converter with current compensation
Authors: Zhao Dongdong , Li Haiyan , Liang Zehua , Ma Rui , Huangfu Yigeng
Published: February 2021

An interleaved DC–DC boost converter is widely used in DC power systems such as fuel cell systems or other systems requiring high‐power quality for increasing and stabilising the output voltage. The performance of the converter can be affected by the control strategy. In this study, a robustness continuous control set model predictive control (CCS‐MPC) for an interleaved DC–DC boost converter is proposed to achieve optimised transient dynamics and steady performance. To deal with unknown load variation and systems uncertainties, an extended Kalman observer is designed to estimate the lumped disturbance, including the load variation and unmodelled part. Based on the disturbance estimation, a dynamic current reference with the disturbance and the integrated voltage error is formulated for the optimal voltage tracking. Also, a prediction‐accuracy‐enhanced CCS‐MPC for a wide range of operation points and multi‐parameter disturbance is obtained. The proposed approach could stabilise the output voltage with good robustness under external disturbance and operation point change. Compared with other existing controllers, i.e. a proportional–integral controller, a sliding mode controller, and a finite control set model predictive controller, both the steady and transient performances are validated by a simulation and experimental test bench.
Heterodyne multiplier‐based inverter
Authors: Kujman Tomer , Singer Sigmond
Published: February 2021

In this study, an innovative realisation of a heterodyne multiplier is proposed, in the field of power inverters, as an alternative to existing systems in the literature. It is shown that by proper choice of control signals, it is possible to reduce the number of components by a factor of three at least, as compared to existing applications. Additionally, it is possible to considerably reduce the amplitude of harmonics in the switching frequency. As a result, considerable improvement in frequency multiplier efficiency is seen, without detriment to the low total harmonic distortion (THD) achievable by the use of frequency multipliers. The advantages of this method have been shown in AC–AC converters as well as DC–AC converters. Finally, a 4.2‐kW model was built with an efficiency of 98.7% and a THD of <2.2%.
Passivity enhancement for LCL‐filtered grid‐connected inverters using the dominant‐admittance‐based controller
Authors: Chen Wenzhe , Zhao Jianfeng , Liu Kangli , Cao Wu
Published: February 2021

LCL filters are widely used for power quality improvement. However, its resonance complicates the design process. Although the single‐loop filter‐based control reduces the cost, it is not reliable because of the grid impedance variation at the point of common coupling (PCC). This study proposes a dominant‐admittance‐based controller to improve the passivity of the inverter. Meanwhile, no extra hardware cost increases. It first offers a single‐loop damping method using a low‐pass filter, which frees inverter from the conventional limitation (fres>fs/6). A graphical procedure is applied to coordinate the current loop design to mitigate the low‐pass filter's negative effects on bandwidth. Then it introduces the dominant admittance concept for the inverter with PCC voltage feedforward control, which provides a new starting point for the admittance reshaping of the filter‐based damping inverter. Based on this concept, a PCC voltage feedforward control using a second‐order low‐pass filter is presented. The inverter output admittance is passive up to the Nyquist frequency with the feedforward control. Although the additional control loop is introduced, the controller requires no extra sensors because the PCC voltage measurement has already existed for the grid synchronisation. Experimental results validate the proposed scheme.
LMI‐based robust controller design and implementation for Z‐source inverters
Authors: Ahmadi Amirhossein , Mohammadi Payman , Mohammadi‐Ivatloo Behnam , Moradi Amani Ali
Published: February 2021

In this study, robust control of impedance source inverters in the presence of uncertainties such as parameters perturbation, unmodelled dynamics and load disturbances, is addressed. These uncertainties, which are naturally available in any power system, have a profound impact on the performance of power inverters and may lead to performance degradation or even instability of the system. A novel LMI‐based design procedure is presented to guarantee the stability of the inverter subject to uncertainties in a Lyapunov‐based framework while a certain level of disturbance rejection is satisfied. Simulation results demonstrate the superior performance of the presented method against comparative controllers. Finally, the proposed controller is applied to an experimental system and the results are compared with simulations, where both substantiate the potency of the proposed controller.
High‐speed gate driver circuit of SiC‐MOSFET for high temperature application
Authors: Zhou Min , Lv Hongliang , Zhang Yimeng , Xu Shuai , Zhang Yuming
Published: February 2021

In this study, a silicon carbide (SiC) MOSFET driving circuit and its protection circuit applied to high temperature (HT) environment are designed by using commercial off‐the‐shelf discrete components. The proposed driving circuit can work at C with a low driving dissipation. An isolation structure with a transformer is utilised to prevent the control circuits from being disturbed by the power circuit. The high value of output driving voltage is 19 V to ensure the low on‐resistance of SiC MOSFET, while the low value of is  V to ensure the SiC MOSFET not be turned on mistakenly. The driving circuit also solves the the contradiction between the BJT switch speed and power dissipation of conventional HT SiC MOSFET driving circuit. The rising time and falling time of the output are reduced greatly, which can increase the performance of SiC MOSFET in high frequency application at a HT.
CBPWM and SVPWM equivalent relationship on single‐phase NPC N‐level inverters with arbitrary sequence
Authors: He Yingjie , Liu Yunfeng , Lei Chao , Cheng Ruiqi , Liu Jinjun
Published: February 2021

Single‐phase multilevel neutral‐point‐clamped (NPC) voltage source inverter has been widely applied in AC traction drive system, the carrier‐based pulse width modulation (CBPWM) method and the space vector pulse width modulation (SVPWM) method are mainly two modulation methods for single‐phase NPC multilevel converters, and there is a certain relationship between these two modulation strategies. In this study, the unified relationship between SVPWM and CBPWM in single‐phase three‐level and five‐level NPC has been analysed. Then by injecting the zero‐sequence component into the initial modulation wave, the same switching state and output current as SVPWM can be achieved through modulation waves decomposed under the CBPWM strategy. Finally, the unified theory of SVPWM and CBPWM in an N‐level inverter with an arbitrary number of segments sequence was deduced. The simulation and experimental results illustrate that the unified theory between CBPWM and SVPWM is correct. With the zero‐sequence injected, CBPWM can realise the same effect as SVPWM, but the former is simpler than the latter, which is easy to promote for higher‐level applications.
Cascaded full‐bridge resonant inverter configuration for different material vessel induction cooking
Authors: Khatroth Srinivas , Shunmugam Porpandiselvi
Published: February 2021

This paper presents a cascaded full‐bridge resonant inverter configuration for different material vessel induction cooking. The proposed inverter configuration features simultaneous heating of three different material vessels, and independent power control. In this proposed work, three different induction heating loads are simultaneously operated at their respective resonant frequencies. Vessels of iron, steel, and aluminium materials are used. The output powers are independently controlled by an asymmetric duty cycle control. The proposed inverter is designed and hardware prototype has been implemented. Experimental results are validated with simulation results.