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16篇 您的检索式:作者名="M.KING"
    题名 作者 年代 出处 被引量
1Stiffness-damping matching method of an ECAS system based on LQG control显示文摘A novel method of matching stiffness and continuous variable damping of an ECAS(electronically controlled air suspension) based on LQG(linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus.Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics,a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests.By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency,the control algorithm of the target suspension height(i.e.,stiffness) was derived according to driving speed and road roughness.Taking account of the nonlinearities of a continuous variable semi-active damper,the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force,which was calculated based on LQG control.Finally,a GA(genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method.Simulation results indicate that compared with the GA-based matching method,both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method,with peak values of the dynamic tire force PSD(power spectral density) decreased by 73.6%,60.8% and 71.9% in the three cases,and corresponding reduction are 71.3%,59.4% and 68.2% for the vehicle body vertical acceleration.A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.陈一锴 何杰 M.KING 陈无畏 张卫华 2014Journal of Central South University2014,21,1:8
2Comparison of two suspension control strategies for multi-axle heavy truck显示文摘Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver's seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level.陈一锴 何杰 M.King 冯忠祥 张卫华 2013Journal of Central South University2013,20,2:5
3Spontaneous clearance of childhood hepatitis C virus infection显示文摘L. T. F.Yeung T.To S. M.King E. A.Roberts 2007Journal of Viral Hepatitis2007,,11:1
4Spontaneous clearance of childhood hepatitis C virus infection显示文摘L. T. F.Yeung T.To S. M.King E. A.Roberts 2007Journal of Viral Hepatitis2007,,11:1
5Role of magnetic field evolution on filamentary structure formation in intense laser–foil interactions显示文摘Filamentary structures can form within the beam of protons accelerated during the interaction of an intense laser pulse with an ultrathin foil target. Such behaviour is shown to be dependent upon the formation time of quasi-static magnetic field structures throughout the target volume and the extent of the rear surface proton expansion over the same period.This is observed via both numerical and experimental investigations. By controlling the intensity profile of the laser drive,via the use of two temporally separated pulses, both the initial rear surface proton expansion and magnetic field formation time can be varied, resulting in modification to the degree of filamentary structure present within the laser-driven proton beam.M.King N.M.H.Butler R.Wilson R.Capdessus R.J.Gray H.W.Powell R.J.Dance H.Padda B.Gonzalez-Izquierdo D.R.Rusby N.P.Dover G.S.Hicks O.C.Ettlinger C.Scullion D.C.Carroll Z.Najmudin M.Borghesi D.Neely P.McKenna 2019High Power Laser Science and Engineering2019,7,1:1
6Later-Life Migrations in Canada in 2001:A Multilevel Approach显示文摘Karen M.King K.Bruce Newbold 0,,2:1
7EUROTRA:多语机器翻译的尝试显示文摘EUROTRA是在欧洲共同体委员会赞助下当前正在设计的一个机器翻译系统。此项设计的基本原理是由模块化设计来实现多语之间的翻译,使多语转换模块跟单语分析模块和单语生成模块严格分开。模块之间的交流是通过一个接口结构进行的。这个接口结构的定义已为参加设计的各小组所公认。这个系统的一致性是由接口结构来保证的,通过使用共同的数据结构来掌握全部加工的结果,并通过使用共同的软件来操纵数据结构。M.King 刘敏 1985当代语言学1985,,1:1
8Atomic Layer Deposition of UV‐Absorbing ZnO Films on SiO显示文摘David M.King XinhuaLiang Casey S.Carney Luis F.Hakim PengLi Alan W.Weimer 2008Adv Funct Mater2008,,4:1
9Randomized clinical trial comparing laparoscopic and open surgery for colorectal cancer within an enhanced recovery programme显示文摘P. M.King J. M.Blazeby P.Ewings P. J.Franks R. J.Longman A. H.Kendrick R. M.Kipling R. H.Kennedy 2006Br J Surg2006,,3:1
10Optimization and control of synchrotron emission in ultraintense laser–solid interactions using machine learning显示文摘The optimum parameters for the generation of synchrotron radiation in ultraintense laser pulse interactions with planar foils are investigated with the application of Bayesian optimization,via Gaussian process regression,to 2D particle-incell simulations.Individual properties of the synchrotron emission,such as the yield,are maximized,and simultaneous mitigation of bremsstrahlung emission is achieved with multi-variate objective functions.The angle-of-incidence of the laser pulse onto the target is shown to strongly influence the synchrotron yield and angular profile,with oblique incidence producing the optimal results.This is further explored in 3D simulations,in which additional control of the spatial profile of synchrotron emission is demonstrated by varying the polarization of the laser light.The results demonstrate the utility of applying a machine learning-based optimization approach and provide new insights into the physics of radiation generation in laser-foil interactions,which will inform the design of experiments in the quantum electrodynamics(QED)-plasma regime.J.Goodman M.King E.J.Dolier R.Wilson R.J.Gray P.McKenna 2023High Power Laser Science and Engineering2023,11,3:0
11Automated control and optimization of laser-driven ion acceleration显示文摘The interaction of relativistically intense lasers with opaque targets represents a highly non-linear,multi-dimensional parameter space.This limits the utility of sequential 1D scanning of experimental parameters for the optimization of secondary radiation,although to-date this has been the accepted methodology due to low data acquisition rates.High repetition-rate(HRR)lasers augmented by machine learning present a valuable opportunity for efficient source optimization.Here,an automated,HRR-compatible system produced high-fidelity parameter scans,revealing the influence of laser intensity on target pre-heating and proton generation.A closed-loop Bayesian optimization of maximum proton energy,through control of the laser wavefront and target position,produced proton beams with equivalent maximum energy to manually optimized laser pulses but using only 60%of the laser energy.This demonstration of automated optimization of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources.B.Loughran M.J.V.Streeter H.Ahmed S.Astbury M.Balcazar M.Borghesi N.Bourgeois C.B.Curry S.J.D.Dann S.DiIorio N.P.Dover T.Dzelzainis O.C.Ettlinger M.Gauthier L.Giuffrida G.D.Glenn S.H.Glenzer J.S.Green R.J.Gray G.S.Hicks C.Hyland V.Istokskaia M.King D.Margarone O.McCusker P.McKenna Z.Najmudin C.Parisuaña P.Parsons C.Spindloe D.R.Symes A.G.R.Thomas F.Treffert N.Xu C.A.J.Palmer 2023High Power Laser Science and Engineering2023,11,3:0
12Structural brain differences between ultra-endurance athletes and sedentary persons显示文摘Participation in ultra-endurance events has increased in recent years and requires extreme levels of moderate to vigorous physical activity(MVPA).Moderate levels of MVPA have been associated with increased brain volume but the effects of extreme levels of MVPA on brain volume is unknown.As a result,we sought to compare the brains of those who engage in extremely high levels of MVPA with those who are sedentary using magnetic resonance imaging.We performed whole brain volumetric analyses and voxel-based morphometry on 12 ultraendurance athletes(1078.75±407.86 min of MVPA/week)and 9 sedentary persons(18.0±56.9 min of MVPA/week).Whole-brain analyses revealed that those who participate in ultra-endurance training have increased grey(p<0.0001),white(p=0.031),and total matter volume(p<0.0001),while regional analyses revealed that ultra-endurance athletes have smaller regional grey matter volume in the right primary sensory and motor cortex,inferior and middle frontal gyrus,and left thalamus.Future research is warranted to determine why ultra-endurance athletes have lower regional volumes in these areas despite having overall increased grey and white matter volumes.T.Paruk L.Rauch M.Jankiewicz K.Van Breda D.J.Stein M.King 2020Sports Medicine and Health Science2020,2,2:0
13Effect of rear surface fields on hot, refluxing and escaping electron populations via numerical simulations显示文摘After a population of laser-driven hot electrons traverses a limited thickness solid target,these electrons will encounter the rear surface,creating TV/m fields that heavily influence the subsequent hot-electron propagation.Electrons that fail to overcome the electrostatic potential reflux back into the target.Those electrons that do overcome the field will escape the target.Here,using the particle-in-cell(PIC)code EPOCH and particle tracking of a large population of macro-particles,we investigate the refluxing and escaping electron populations,as well as the magnitude,spatial and temporal evolution of the rear surface electrostatic fields.The temperature of both the escaping and refluxing electrons is reduced by 30%–50%when compared to the initial hot-electron temperature as a function of intensity between 1019 and 1021 W/cm^2.Using particle tracking we conclude that the highest energy internal hot electrons are guaranteed to escape up to a threshold energy,below which only a small fraction are able to escape the target.We also examine the temporal characteristic of energy changes of the refluxing and escaping electrons and show that the majority of the energy change is as a result of the temporally evolving electric field that forms on the rear surface.D.R.Rusby C.D.Armstrong G.G.Scott M.King P.McKenna D.Neely 2019High Power Laser Science and Engineering2019,7,3:0
14High order modes of intense second harmonic light produced from a plasma aperture显示文摘Because of their ability to sustain extremely high-amplitude electromagnetic fields and transient density and field profiles,plasma optical components are being developed to amplify,compress,and condition high-power laser pulses.We recently demonstrated the potential to use a relativistic plasma aperture—produced during the interaction of a high-power laser pulse with an ultrathin foil target—to tailor the spatiotemporal properties of the intense fundamental and second-harmonic light generated[Duff et al.,Sci.Rep.10,105(2020)].Herein,we explore numerically the interaction of an intense laser pulse with a preformed aperture target to generate second-harmonic laser light with higher-order spatial modes.The maximum generation efficiency is found for an aperture diameter close to the full width at half maximum of the laser focus and for a micrometer-scale target thickness.The spatial mode generated is shown to depend strongly on the polarization of the drive laser pulse,which enables changing between a linearly polarized TEM01 mode and a circularly polarized Laguerre–Gaussian LG01 mode.This demonstrates the use of a plasma aperture to generate intense higher-frequency light with selectable spatial mode structure.E.F.J.Bacon M.King R.Wilson T.P.Frazer R.J.Gray P.McKenna 2022Matter and Radiation at Extremes2022,7,5:0
15Reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature显示文摘The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high-intensity interaction when using a regular structure with known spacing.J.Jarrett M.King R.J.Gray N.Neumann L.Dhl C.D.Baird T.Ebert M.Hesse A.Tebartz D.R.Rusby N.C.Woolsey D.Neely M.Roth P.McKenna 2019High Power Laser Science and Engineering2019,7,1:0
16Versatile tape-drive target for high-repetition-rate laser-driven proton acceleration显示文摘We present the development and characterization of a high-stability,multi-material,multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 Hz.The tape surface position was measured to be stable on the sub-micrometre scale,compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers(>kHz).Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended periods.The target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team,with the exception of tape replacement,producing the largest data-set of relativistically intense laser–solid foil measurements to date.This tape drive provides robust targetry for the generation and study of high-repetitionrate ion beams using next-generation high-power laser systems,also enabling wider applications of laser-driven proton sources.N.Xu M.J.V.Streeter O.C.Ettlinger H.Ahmed S.Astbury M.Borghesi N.Bourgeois C.B.Curry S.J.D.Dann N.P.Dover T.Dzelzainis V.Istokskaia M.Gauthier L.Giuffrida G.D.Glenn S.H.Glenzer R.J.Gray J.S.Green G.S.Hicks C.Hyland M.King B.Loughran D.Margarone O.McCusker P.McKenna C.Parisuaña P.Parsons C.Spindloe D.R.Symes F.Treffert C.A.J.Palmer Z.Najmudin 2023High Power Laser Science and Engineering2023,11,2:0
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