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Improved state-space Modelling for Microgrids Without Virtual Resistances

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Journal of Modern Power systems and Clean Energy 2024年第2期12卷 584-596页

作者： Paranagamage s.A.Peiris shaahin Filizadeh Dharshana Muthumuni Department of Electrical and Computer Engineering University of ManitobaWinnipegMBR3T 5V6Canada Manitoba HVDC Research Center 211 Commerce DriveWinnipegMBR3P 1A3Canada IEEE

Power converters and their interfacing networks are often treated as modular state-space blocks for small-signal stability studies in microgrids;they are interconnected by matching the input and output states of the network and *** resistors have been widely used in existing models to generate a voltage for state-space models of the network that require voltage *** paper accurately quantifies the adverse impacts of adding the virtual resistance and proposes an alternative method for network modelling that eliminates the requirement of the virtual resistor when interfacing converters with *** proposed nonlinear method allows initialization,time-domain simulations of the nonlinear model,and linearization and eigenvalue generation.A numerically linearized small-signal model is used to generate eigenvalues and is compared with the eigenvalues generated using the existing modelling method with virtual *** of the existing method and improvements offered by the proposed modelling method are clearly *** transient(EMT)simulations using detailed switching models are used for validation of the proposed modelling method.

关键词： Low-voltage converter state-space modelling dynamic phasor time-domain simulation eigenvalue analysis

A study of the Comets with Large Perihelion Distances C/2019 L3(ATLAs)and C/2019 O3(Palomar)

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Research in Astronomy and Astrophysics 2024年第9期24卷 199-213页

作者： Alberto s.Betzler Centro de Ciencia e Tecnologia em Energia e sustentabilidade Universidade Federal do Recôncavo da BahiaFeira de SantanaBahia44.085-132Brazil

This work analyzes the photometric data of the Oort spike comets C/2019 L3(ATLAs)and C/2019 O3(Palomar)obtained between 2016 and 2023 by the ATLAs network and the Belgian Olmen *** comets Palomar and ATLAs have a typical and unusually high activity level,respectively,based on the Afρparameter corrected to phase angle zero at *** absolute magnitude of comets ATLAs and Palomar in the o-band is 4.71±0.05 and 4.16±0.02 *** cometary activity of comets ATLAs and Palomar probably began at r>13 au before perihelion and will end at r>14 au after perihelion,which means that they could remain active until the second half of *** nucleus of comet ATLAs has a minimum radius of 7.9 km,and the nucleus of comet Palomar could be a little *** c-o colors of the comets ATLAs and Palomar are redder and bluer,respectively,at perihelion than the solar twin YBP *** comets showed a bluish trend in the coma color with decreasing heliocentric *** Palomar probably had two outbursts after its perihelion,each releasing about 10^(8)kg of *** slopes of the photometric profile of the comae of these comets were between 1and 1.5,indicating a steady state during the observation campaign.

关键词： individual C/2019 L3(ATLAs) C/2019 O3(Palomar) techniques:photometric methods:data analysis

Fuzzy Reliability and Availability of system under a Calendar-based Inspection Involving Multiple Failures and Its Application to Wind Turbine system

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Journal of systems science and systems Engineering 2024年第2期33卷 187-206页

作者： Mintu Kumar Himani Pant s.B.singh Department of Mathematics statistics and Computer science G.B.Pant University of AgricultureTechnologyPantnagarUttarakhandIndia

Uncertainty is an important factor that needs to be considered while analyzing the performance of any engineering *** order to quantify uncertainty,fuzzy set theory is frequently used by most of researchers,including energy system *** to the classical reliability theory,component lifetimes have crisp parameters,but due to uncertainty and inaccuracy in data,it is sometimes very difficult to determine the exact values of these parameters in real-world *** overcome this difficulty in the current research,failure and repair rates were taken as triangular fuzzy numbers to determine the fuzzy availability of a system undergoing calendar-based periodic inspection subject to multiple failure modes(FMs).It was assumed that each component in the system had an exponential failure rate and repair rate with fuzzy *** FMs were explicitly taken into account when a functional state of the system was *** FM had a random failure *** the occurrence of any failure,a random time was selected for the relevant corrective repair *** proposed research was studied for one of the major sources of green energy,namely a wind turbine system wherein all the derived propositions have been implemented on it.

关键词： Fuzzy reliability fuzzy availability wind turbine system multiple failure modes triangular fuzzy number

Making connections with cell surface auxin signaling

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Molecular Plant 2024年第4期17卷 522-524页

作者： Angus s.Murphy University of Maryland College ParkMDUSA

The discovery and characterization of the nuclear AUX-indole-3-acetic acid(IAA)-TIR1/AFB auxin co-receptor complex in the model plant Arabidopsis at the outset of the 21st century was a hallmark event in biological *** decades of subsequent discovery demonstrated the central role of the nuclear auxin perception mechanism in virtually every stage of Viridiplantae *** auxin receptors were also shown to be essential for later stages of differential hypocotyl,coleoptile,and root tropisms,but the most rapid responses were found to persist in Arabidopsis mutants lacking important components of the receptor mechanism(Napier,2021;Peer and Murphy,2022).In particular,rapid cellular elongation observed in tropic growth or after experimental application of auxin is mediated by H+extrusion across the plasma membrane(PM).The resulting apoplastic acidification activates extensin proteins that loosen cell walls to allow for turgor-driven cellular *** initial events occur in a time frame that precludes nuclear signaling and now can be clearly attributed to a cell surface auxin co-receptor complex and downstream signaling intermediaries.

关键词： Arabidopsis surface walls

Flexible ultra-thin super-resolution endoscopy

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science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 171-172页

作者： George s.D.Gordon Department of Electrical and Electronic Engineering University of NottinghamNottingham NG7 2RDUK

In recent years, multimode fiber(MMF) has become an important tool for high-resolution endoscopic imaging in narrow channels(e.g., in the brain via needles or inside blood vessels) due to its high mode density and fine diameter, typically stacle to widespread deployment in applications is that realistic perturbations, including bending, twisting and changes in temperature, cause unacceptable image degradation.

关键词： fiber resolution typically

Geochemistry and depositional environment of fuchsite quartzites from sargur Group,western Dharwar Craton,India

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Acta Geochimica 2024年第3期43卷 555-570页

作者： C.s.sindhuja G.Harshitha C.Manikyamba K.s.V.subramanyam CsIR(Council of scientific and Industrial Research)-National Geophysical Research Institute(NGRI) Uppal RoadHyderabad 500007India

Meso-Neoarchean fuchsite quartzites are present in different stratigraphic positions of Dharwar Craton including the oldest(~3.3 Ga)sargur Group of western Dharwar *** present study deals with the petro-graphic and geochemical characteristics of the fuchsite quartzites from the Ghattihosahalli belt to evaluate their genesis,depositional setting and the enigma involved in the ancient sedimentation *** major mineral assemblages include quartz,fuchsite,and feldspars along with accessory kyanite and *** geochemical com-positions are characterized by high siO_(2),Al_(2)O_(3),low MgO,CaO,strongly enriched Cr(1326–6899 ppm),Ba(1165–3653 ppm),sr(46–210 ppm),V(107–868 ppm)and Zn(11–158 ppm)contents compared to the upper continental crust(UCC).The UCC normalized rare earth element(REE)patterns are characterized by depleted light REE[(La/sm)UCC=0.33–0.95]compared to heavy REE[(Gd/Yb)_(UCC)=0.42–1.65]with conspicuous positive Eu-anomalies(Eu/Eu^(*)=1.35–18.27)characteristic of hydrothermal solutions evidenced through the interlayered *** overall major and trace element systematics reflect a combined mafic-felsic provenance and suggest their deposition at a passive continental margin *** comprehensivefield,petrographic,and geo-chemical studies indicate that these quartzites are infiltrated by Cr-richfluids released during high-grade metamorphism of associated ultramafic *** sargur and the subse-quent Dharwar orogeny amalgamated diverse lithounits from different tectonic settings,possibly leading to the release of Cr-richfluids and the formation of fuchsite quartzite during or after the *** sug-gest a pre-existing stable crust prior to the sargur Group and the link between orogenic events and various mineral deposits in the Dharwar Craton.

关键词： Dharwar Craton Ghattihosahalli Fuchsite quartzite Provenance Depositional setting

Explainable Conformer Network for Detection of COVID-19 Pneumonia from Chest CT scan: From Concepts toward Clinical Explainability

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Computers, Materials & Continua 2024年第1期78卷 1171-1187页

作者： Mohamed Abdel-Basset Hossam Hawash Mohamed Abouhawwash s.s.Askar Alshaimaa A.Tantawy Faculty of Computers and Informatics Zagazig UniversityZagazig44519Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast LansingMI48824USA Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of statistics and Operations Research College of ScienceKing Saud UniversityP.O.Box 2455Riyadh11451Saudi Arabia

The early implementation of treatment therapies necessitates the swift and precise identification of COVID-19 pneumonia by the analysis of chest CT *** study aims to investigate the indispensable need for precise and interpretable diagnostic tools for improving clinical decision-making for COVID-19 *** paper proposes a novel deep learning approach,called Conformer Network,for explainable discrimination of viral pneumonia depending on the lung Region of Infections(ROI)within a single modality radiographic CT ***,an efficient U-shaped transformer network is integrated for lung image ***,a robust transfer learning technique is introduced to design a robust feature extractor based on pre-trained lightweight Big Transfer(BiT-L)and finetuned on medical data to effectively learn the patterns of infection in the input ***,this work presents a visual explanation method to guarantee clinical explainability for decisions made by Conformer *** evaluation of real-world CT data demonstrated that the diagnostic accuracy of ourmodel outperforms cutting-edge studies with statistical *** Conformer Network achieves 97.40% of detection accuracy under cross-validation *** model not only achieves high sensitivity and specificity but also affords visualizations of salient features contributing to each classification decision,enhancing the overall transparency and trustworthiness of our *** findings provide obvious implications for the ability of our model to empower clinical staff by generating transparent intuitions about the features driving diagnostic decisions.

关键词： Deep learning COVID-19 multi-modal medical image fusion diagnostic image fusion

Role of climatic variability in shaping intraspecific variation of thermal tolerance in Mediterranean water beetles

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Insect science 2024年第1期31卷 285-298页

作者： susana Pallarés David Garoffolo Belén Rodríguez David sánchez-Fernández Department of Zoology University of SevilleSevilleSpain Faculty of Biology Department of Ecology and HydrologyUniversity of MurciaCampus EspinardoMurciaSpain

The climatic variability hypothesis(CVH)predicts that organisms in more thermally variable environments have wider thermal breadths and higher thermal plasticity than those from more stable ***,due to evolutionary trade-offs,taxa with greater absolute thermal limits may have little plasticity of such limits(trade-off hypothesis).The CVH assumes that climatic variability is the ultimate driver of thermal tolerance variation across latitudinal and altitudinal gradients,but average temperature also varies along such *** explored intraspecific variation of thermal tolerance in three typical Mediterranean saline water beetles(families Hydrophilidae and Dytiscidae).For each species,we compared two populations where the species coexist,with similar annual mean temperature but contrasting thermal variability(continental *** population).We estimated thermal limits of adults from each population,previously acclimated at 17,20,or 25℃.We found species-specific patterns but overall,our results agree with the CVH regarding thermal ranges,which were wider in the continental(more variable)*** the two hydrophilid species,this came at the cost of losing plasticity of the upper thermal limit in this population,supporting the trade-off hypothesis,but not in the dytiscid *** results support the role of local adaptation to thermal variability and trade-offs between basal tolerance and physiological plasticity in shaping thermal tolerance in aquatic ectotherms,but also suggest that intraspecific variation of thermal tolerance does not fit a general pattern among aquatic *** such intraspecific variation could lead to inaccurate predictions of the vulnerability of aquatic insects to global warming.

关键词： acclimation capacity aquatic insects climate change heat coma temperature supercooling point thermal plasticity

Optimizing Average Electric Power During the Charging of Lithium-Ion Batteries Through the Taguchi Method

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Transactions of Tianjin University 2024年第2期30卷 152-166页

作者： Mohd H.s.Alrashdan Department of Electrical Engineering Al-Hussein Bin Talal UniversityMaan 71110Jordan

In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. This challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the Taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. The Taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. The proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. Three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the Taguchi analysis. The results revealed that the Taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. This indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. The identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17

关键词： Lithium-ion batteries Average electric power during charging Taguchi method COMsOL Multiphysics software C rate L27 orthogonal array