bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust load frequency control for networked power system with renewable energy via fractional‐order global sliding mode control
Authors: Lv Xinxin , Sun Yonghui , Hu Wenqiang , Dinavahi Venkata 
Published: January 2021

AbstractOwing to random load changes and transmission time delays in interconnected power systems with renewable energy, the load frequency control scheme has become one of the main methods to keep stability and security of power systems. To relieve communication burden and increase network utilisation, an adaptive event‐triggered scheme is explored. Then, a new fractional‐order global sliding mode control scheme comprising the fractional‐order term in the sliding surface is adopted to improve robustness of load frequency control. The fractional‐order term generates a new degree of freedom and more adjustable parameters to improve control performance. Furthermore, the Markov theory is applied in the modelling process to better describe the uncertainty of parameters and external disturbances. The stability and stabilisation criteria for multi‐area power systems load frequency control are put forward by employing the improved Lyapunov function and integral inequalities with auxiliary functions. Finally, two simulation examples containing a two‐area power system and modified IEEE 39‐bus New England test power system with three wind farms are presented to investigate the effectiveness of the proposed method.
Operational strategy optimisation of VRB energy storage systems considering the dynamic characteristics of VRB in active distribution networks
Authors: Lei Jiazhi , Gao David Wenzhong , Liu Jinhong 
Published: January 2021

AbstractStrategy optimisation of large‐scale battery energy storage system (BESS) operation in active distribution networks (ADNs) is an actively pursued research topic concerned by electric power researchers. This study proposes a dynamic programming method (DPM)‐based operational strategy optimisation of vanadium redox flow battery (VRB) ESSs for the comprehensive performance of ADNs considering the dynamic characteristics of VRB. The dynamic characteristics of VRB based on self‐discharge rate, dynamic efficiencies, maximum absorption power, cycle life and apparent power are reasonably proposed to construct the operational restrictions of ESSs. VRB is safely and reasonably operated with high cycle life and ideal states by these dynamic operational restrictions. And then, DPM is used to decompose the multivariate optimisation problem into several univariate optimisation problems. Finally, different case studies showed that the developed operation strategy of VRB ESSs can greatly improve both the economy and the voltage quality of ADNs. Also, the curtailment rate of renewable energy in ADNs is greatly reduced by about 50% and VRB ESSs can get a perfect optimisation associated with a higher utilisation rate of about 0.8 and an ameliorative average efficiency of about 0.753.
Transient modelling of doubly‐fed induction generator based wind turbine on full operation condition and rapid starting period based on low voltage ride‐through testing
Authors: Yan Xiangwu , Cui Sen , Sun Xuewei , Sun Ying 
Published: January 2021

AbstractTransient simulation model of doubly‐fed induction generator‐based wind turbine has a complex model structure and considerable control parameters. An accurate simulation model is especially important for studying the static and transient characteristics of doubly‐fed induction generator‐based wind turbine and the grid‐connected system. Based on the measured data of low voltage ride‐through testing, the integrated parameter identification method is proposed here. Combined with the time‐domain simulation analysis, curve fitting is used to determine the control strategy of doubly‐fed induction generator‐based wind turbine. The improved genetic algorithm is used to identify the generator parameters, power control parameters, and resistance of Crowbar of doubly‐fed induction generator‐based wind turbine. Combined with the electrical parameters provided by the wind turbine manufacturer, electromagnetic transient model on full operation condition and rapid starting period, corresponding to a measured doubly‐fed induction generator‐based wind turbine in West Inner Mongolia Power Grid, is then established, which can operate in the full wind speed range and quickly enter the stable state within 1 s after start‐up. Comparison of simulation results and measured data shows that the established electromagnetic transient simulation model using parameters identified by the proposed method can accurately reflect the key characteristics of doubly‐fed induction generator‐based wind turbine.
Planning for resilience in power distribution networks: A multi‐objective decision support
Authors: Jamborsalamati Pouya , Garmabdari Rasoul , Hossain Jahangir , Lu Junwei , Dehghanian Payman 
Published: January 2021

AbstractPower grid response against high‐impact low‐probability (HILP) events could be enhanced by (a) hardening mechanisms to boost its structural resilience and (b) corrective recovery and mitigation analytics to improve its operational resilience. Planning for structural resilience and attempts to find the optimal location of the Tie switches in radially operated power distribution networks that enable harnessing the network topology for maximised resilience against HILP disasters are focussed. This goal is achieved through a novel resilience‐oriented multi‐objective decision making platform, which employs a k‐PEM based probabilistic power flow (PPF) algorithm. The proposed framework offers a decision making analytic embedded with the fuzzy satisfying method (FSM) that characterises the system resilience features, such as robustness, restoration agility, load criticality, and recovered capacity, to assess different network reconfiguration options and select the optimal solution for implementation. The aforementioned resilience features are formulated in nodal level and then aggregated over the entire system to characterise the system‐level objective functions. The performance of the suggested framework is analysed on the IEEE 33‐Bus test system under a designated HILP event, and the applicability on larger networks has been verified on the IEEE 69‐bus test system. The results demonstrate the efficacy and applicability of the proposed framework in boosting the network resilience against future extremes.
Index modulation for OFDM RadCom systems
Authors: Huang Gaojian , Ding Yuan , Ouyang Shan , Fusco Vincent 
Published: January 2021

AbstractThis paper studies a novel Radar and wireless communication fusion system namely, RadCom, using orthogonal frequency division multiplexing index modulation waveforms. From the communication perspective, information is conveyed not only through modulated orthogonal frequency division multiplexing subcarriers but also by the active subcarrier indices that are dynamically updated at the transmitted symbol rates. When compared with conventional orthogonal frequency division multiplexing communication systems, only a subset of subcarriers is activated in the proposed orthogonal frequency division multiplexing index modulation system, which reduces signal peak‐to‐average ratios, leading to enhanced power amplifier efficiency. From the Radar sensing perspective, the Radar range‐velocity profile obtained using compressed sensing approach is simulated and presented. It is shown that orthogonal frequency division multiplexing index modulation RadCom system can enhance the transmission data rates when low‐order modulation schemes are adopted e.g. binary phase shift keying, and maintain similar Radar performance compared with the orthogonal frequency division multiplexing counterpart when the system is carefully designed.
Optical wireless power transmission characteristics of surface appearance controlled solar cells using visible colour filters
Authors: Liu Yu , Miyamoto Tomoyuki 
Published: January 2021

AbstractOptical wireless power transmission (OWPT) systems are attractive photonic systems based on light sources and solar cells. To improve the visual design of practical consumer applications, we applied visible colour filters to change the normal black appearance of solar cells. Different colours made by multilayer‐type filters on solar cells were investigated for control of visible colour with maintained power transmission efficiency. The surface colours seen by the eyes and standard cameras were controlled by the filter as expected from the filter spectral response. The electrical output characteristics of the solar cell covered with the filter were experimentally measured in order to confirm the OWPT performance. The results showed that the OWPT system can change colour appearance with an acceptable slight deterioration of performance.
Predictive Value of Transcranial Evoked Potential Monitoring for Intramedullary Spinal Cord Tumors
Authors: Ille Sebastian , Wagner Arthur , Joerger Ann Kathrin , Wostrack Maria , Meyer Bernhard , Shiban Ehab 
Published: January 2021

Abstract
Background Intraoperative neurophysiologic monitoring (IONM) has increased patient safety and extent of resection in patients with eloquent brain tumors. Despite its comprehensive capability for the resection of intramedullary spinal cord tumors (ISCTs), the application during the resection of these tumors is controversial.
Methods We retrospectively analyzed the resection of ISCTs in 83 consecutive cases. IONM was performed in all cases. Each patient's motor status and the McCormick scale was determined preoperatively, directly after surgery, at the day of discharge, and at long-term follow-up.
Results IONM was feasible in 71 cases (85.5%). Gross total resection was performed in 75 cases (90.4%). Postoperatively, patients showed new transient deficits in 12 cases (14.5%) and new permanent deficits in 12 cases (14.5%). The mean McCormick variance between baseline and long-term follow-up was − 0.08 ± 0.54. IONM's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the patient's motor status at the day of discharge was 75.0%, 64.7%, 45.5%, and 86.8%. It was 88.9%, 59.7%, 24.2%, and 97.4% for the motor outcome at long-term follow-up. Patients experienced postoperative complications in 15 cases (18.1%).
Conclusion IONM, as performed in the present study, shows a high sensitivity and NPV but low specificity and PPV, particularly for the patient's motor status at the long-term follow-up. As far as practicable by a retrospective study on IONM, our results confirm IONM's usefulness for its application during the resection of ISCTs. However, these results must be approved by a prospective study.
Sensitivity and Negative Predictive Value of Motor Evoked Potentials of the Facial Nerve
Authors: Bovo Nicolas , Momjian Shahan , Gondar Renato , Bijlenga Philippe , Schaller Karl , Boëx Colette 
Published: January 2021

Abstract
Objective The objective of this study was to determine the performance of the standard alarm criterion of motor evoked potentials (MEPs) of the facial nerve in surgeries performed for resections of vestibular schwannomas or of other lesions of the cerebellopontine angle.
Methods This retrospective study included 33 patients (16 with vestibular schwannomas and 17 with other lesions) who underwent the resection surgery with transcranial MEPs of the facial nerve. A reproducible 50% decrease in MEP amplitude, resistant to a 10% increase in stimulation intensity, was applied as the alarm criterion during surgery. Facial muscular function was clinically evaluated with the House–Brackmann score (HBS), pre- and postsurgery at 3 months.
Results In the patient group with vestibular schwannoma, postoperatively, the highest sensitivity and negative predictive values were found for a 30% decrease in MEP amplitude, that is, a criterion stricter than the 50% decrease in MEP amplitude criterion, prone to trigger more warnings, used intraoperatively. With this new criterion, the sensitivity would be 88.9% and the negative predictive value would be 85.7%. In the patient group with other lesions of the cerebellopontine angle, the highest sensitivity and negative predictive values were found equally for 50, 60, or 70% decrease in MEP amplitude. With these criteria, the sensitivities and the negative predictive values would be 100.0%.
Conclusion Different alarm criteria were found for surgeries for vestibular schwannomas and for other lesions of the cerebellopontine angle. The study consolidates the stricter alarm criterion, that is, a criterion prone to trigger early warnings, as found previously by others for vestibular schwannoma surgeries (30% decrease in MEP amplitude).
Long-Term Success of Metal Endobronchial Stents in Lung Transplant Recipients
Authors: Izhakian Shimon , Wasser Walter , Unterman Avraham , Fruchter Oren , Gorelik Oleg , Kramer Mordechai 
Published: January 2021

Abstract
Background Bronchial stenosis is a common complication following lung transplantation. We evaluated long-term associations of the use of self-expandable metal stents (SEMSs) with lung function tests, patient safety, and survival.
Methods A retrospective chart review of 582 lung transplantations performed at our institution between January 2002 and January 2018. Fifty-four patients with SEMSs (intervention group) were matched one-to-one to patients without SEMSs (control group) using propensity score matching for age, sex, the year, and type of transplantation (unilateral/bilateral), and underlying disease. Data regarding long-term lung function and survival were compared between the groups.
Results During a median follow-up of 54.8 months, the difference in survival between the study groups was not statistically significant (p = 0.2). Following 5, 7.5 and 10 years, values of mean forced expiratory volume in 1 second (FEV1) were comparable between patients with and without SEMSs as follows: 59.5 versus 62.6% (p = 0.2), 55.9 versus 55.0% (p = 0.4), and 63.5 versus 61.9% (p = 0.3), respectively. In the intervention group, a significant increase in the mean FEV1 was observed in 60 days after stent insertion (from 41.9 ± 12.8 to 49.5 ± 16.7% days, p < 0.001). Long-term complications following stent insertion included severe bleeding (1.8%), stent fractures (7.4%), stent stenosis (7.4%), stent collapse (3.7%), endobronchial pressure ulcer (1.9%), and stent migration (1.9%).
Conclusion SEMS insertion is associated with a positive sustained effect on lung function, without increasing long-term mortality. Thus, airway stenosis after lung transplantation can be safely and successfully treated using endobronchial metal stenting, with tight bronchoscopic follow-up and maintenance.
Economic Impact of Diagnostic Imaging in the Workup of Uncomplicated Bell's Palsy
Authors: Kazemian Elycia , Schaffer Hollie Marie , Wozniak Amy , Leonetti John P. 
Published: January 2021

Abstract
Objective Our primary objective is to identify the costs associated with imaging in the diagnostic workup of uncomplicated Bell's palsy. Our secondary objective is to identify a dollar amount spent on extraneous diagnostic testing on a state and national level.
Design and Setting Retrospective chart analysis was performed at our tertiary care medical center between 2007 and 2018. International Statistical Classification of Diseases-10 code G51.0 was used to identify patients with Bell's palsy seen by the senior author. A total of 163 patients were divided into two groups: those having received imaging and those diagnosed without imaging. The imaging group was then further subdivided by imaging modality: computed tomography (CT) only, magnetic resonance imaging (MRI) only, or both. There was a total of 138 scans in 115 patients. To quantify the amount spent by insurance companies or patients on these scans, net expected pay (NEP) for each modality was used as a representation of cost. The NEP for a CT was $618. The NEP for an MRI was $1,119. The NEP for both scans was $1,737. We extrapolated our results to a state and national level.
Main Outcome Measurements Cost of workup; state and national economic burden.
Results Extrapolating our data, we forecast that in Illinois and in the United States, over $2 million and $53 million, respectively, are spent on unnecessary imaging.
Conclusion By highlighting an unnecessary financial burden, our study provides concrete evidence to support the American Academy of Otolaryngology's recommendation that clinicians should not perform routine imaging studies when diagnosing uncomplicated Bell's palsy.
Mother-to-Child HIV Transmission among Pregnant Women in a City with the Highest Rates of HIV in Brazil
Authors: Menegotto Mariana , Magdaleno Amanda M. , da Silva Carmem L.O. , Friedrich Luciana , da Silva Clécio H. 
Published: January 2021

Objective Most of the HIV pediatric infections are acquired through mother-to-child transmission (MTCT). Porto Alegre is a state capital of Brazil that had a HIV MTCT rate of 4.1% in 2013 and the highest rate of HIV-infected pregnant women in the country during 2018. Zidovudine and nevirapine have been used in Brazil for high-risk newborns since 2012. The aim of the study was to investigate HIV MTCT rate and the factors associated with HIV transmission at a hospital that is a reference center for HIV-infected mothers in Porto Alegre, after the introduction of this policy.
Study Design This retrospective cohort study included all HIV-exposed infants born between February 2013 and December 2016 at the Hospital de Clínicas de Porto Alegre. Student's t-test or Fisher's exact test was used to compare variables between HIV-infected and uninfected groups of newborns. Poisson's regression with robust variance was used to determine the factors associated with HIV MTCT.
Results A total of 375 newborns were exposed to HIV, with an outpatient loss of 14.4% (n = 54). The HIV MTCT rate was 2.18% (n = 7), with four infected during the intrauterine period. The risk factors for MTCT were no prenatal care (relative risk [RR] = 9.4; 95% confidence interval [CI]: 2.0–44.3), late maternal HIV diagnosis in the peripartum period (RR = 16.3; 95% CI: 3.6–73.0), syphilis infection during pregnancy (RR = 9.3; 95% CI: 2.1–40.3), maternal viral load >1,000 copies/mL in the third trimester or peripartum period (RR = 9.5; 95% CI: 1.7–50.5), and lack of or inappropriate antiretroviral therapy during pregnancy (RR = 8.2; 95% CI: 1.6–41.4).
Conclusion MTCT rate was 2.18%. With the institution of two-drug prophylaxis for high-risk newborns, persistent cases HIV MTCT were predominantly found among women with absence of antenatal care, late HIV diagnosis, syphilis coinfection, high viral load, and inadequate ARV therapy during pregnancy. Although zidovudine and nevirapine were administered postnatally to high-risk newborns, this regimen could not prevent transplacental transmission.
Key Points
Auditory Brain Stem Response Predictors of Hearing Outcomes after Middle Fossa Resection of Vestibular Schwannomas
Authors: Ren Yin , Merna Catherine M. , Tawfik Kareem O. , Schwartz Marc S. , Friedman Rick A. 
Published: January 2021

Abstract
Objectives To analyze the relationship between preoperative and intraoperative auditory brain stem response (ABR) characteristics and hearing outcomes in patients with vestibular schwannomas (VS) undergoing hearing preservation (HP) surgery via a middle cranial fossa (MCF) approach.
Design Prospective study.
Setting Academic tertiary skull base referral center.
Methods Pre- and postoperative pure-tone average (PTA) and word recognition score (WRS) were examined. Intraoperative ABR wave III latency, wave V latency, and amplitude were recorded. HP was defined as postoperative WRS ≥50%.
Participants Adult patients with VS and WRS ≥50% who underwent MCF tumor resection between November 2017 and September 2019.
Main Outcome Measures Postoperative hearing outcomes.
Results Sixty patients were included. Mean tumor size was 9.2 mm (range, 3–17). HP rates were 56.7% for the cohort and 69.7% for tumors <10 mm. A complete loss of wave V was associated with an 82.9% increase in postoperative PTA (p < 0.001) and 97.2% decrease in WRS (p < 0.001), whereas a diminished wave V was correlated with 62.7% increase in PTA (p < 0.001) and 55.7% decrease in WRS (p = 0.006). A diminished or absent wave V, but not increased wave III/V latency or decreased wave V amplitude, was correlated with a decline in postoperative hearing class (r = 0.735, p < 0.001). Receiver-operating characteristic analysis demonstrated that a stable wave V has the highest accuracy in predicting HP (sensitivity of 82.6%, specificity of 84.8%).
Conclusion Of the examined preoperative and intraoperative ABR characteristics, a stable wave V intraoperatively was the strongest predictor of HP after MCF resection of VS.
Level of Evidence Level III.
Development of 10 MHz–1000 MHz small leadless electric field probe
Authors: Sheng Mingjie , Zhou Zhongyuan , Gu Yixing , Hu Peng , Xiao Yang , Zhou Qi 
Published: January 2021

In order to realize the miniaturization and leadless function of the electric field probe working from 10 MHz to 1000 MHz, a small stand-alone probe based on the dipole and Schottky detector diode is developed in this paper. First, a 20 mm dipole printed on the circuit board is adopted as the receiving antenna, and the Schottky detector diode is connected across the two arms of the dipole. Then, the signal output by the detector diode is amplified by a chopper amplifier circuit, which also isolates the alternating component. Finally, a microprogrammed control unit is set inside the metal shield to realize data acquisition and storage. The size of the probe developed is not exceeding 20 × 20 × 30 mm3, and the characteristics of the probe are temperature dependent. The field strength from 1.4 V/m to 1627 V/m can be measured within 10 MHz–1000 MHz, achieving a dynamic range over 61 dB at 21 °C. It has the advantages of small size, large dynamic range, and integrated data collection and storage.
Comparative study of the dynamics of laser breakdown in water and hexane using interference microscopy
Authors: Kononenko V.V. , Gololobov V.M. , Kononenko T.V. , Goncharov E.A. , Konov V.I. 
Published: January 2021

Abstract
The changes in the optical properties of water and hexane under femtosecond irradiation (Ti : Al2O3 laser, wavelength 800 nm, intensity ∼1013 W cm−2) are investigated in the cavitation (bubble-formation) regime using interference microscopy in a time interval of ∼1.5 ns since the impact onset. A comparison of the dynamics of radiation-induced processes (solvation of excess electrons, pair recombination, and development of precavitation processes) is performed. The excited-carrier concentration is estimated, and these estimates are found to be inconsistent with the amount of energy that must be transferred to the liquid during a pulse to implement its heating and subsequent cavitation. This inconsistency is especially pronounced for hexane, where ionisation processes can barely be detected by interferometry. The experimental results put new questions about the mechanisms of energy transfer in both polar and nonpolar liquids subjected to intense laser irradiation.
Pulse energy limitation of high-power nanosecond lasers due to plasma production in spatial filters
Authors: Kuzmin A.A. , Khazanov E.A. , Shaykin A.A. 
Published: January 2021

Abstract
For a neodymium glass laser, which is used to pump the parametric amplifier of the PEARL facility, we investigate the problem of filling the pinholes of vacuum spatial filters with plasma resulting from the ablation of the pinhole surface by laser radiation. The time of plasma expansion is measured and the causes of its appearance are determined, among which the main ones are the spherical aberrations of the lenses of spatial filters, which increase the intensity at the pinhole edges. With the total spherical aberration of the spatial filters, which lowers the Strehl number to 0.15, two nanosecond pulses with energies of 130 – 140 J, delayed relative to each other by 1.8 ns and freely passing through the final spatial filter, are generated on the PEARL facility.