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User Association in Ultra-Dense Small Cell Dynamic Vehicular Networks: A Reinforcement Learning.Approach

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Journal of Communications and Information Networks 2019年第1期4卷 1-12页

作者： Shipra Kapoor David g.ace tim Clarke Department of Electronic Eng.neering University of YorkYO105DDUnited Kingdom

Network densification is envisioned as one of the key enabling.technolog.es in the next g.neration and beyond wireless networks to satisfy the demand of hig. coverag. and capacity whilst deliver an ultra-reliable low latency communication services especially to the users on the *** of the fundamental tasks in wireless networks is user *** the case of ultra-dense vehicular networks,due to the dense deployment and small coverag. of the eNodeBs,there may be more than one eNodeB that may simultaneously satisfy the conventional maximum radio sig.al streng.h user association *** addition to this,the spatial-temporal vehicle distribution in dynamic environments contribute sig.ificantly towards the rapidly chang.ng.radio environment that substantially impacts the user association,therefore,the network performance and user *** paper addresses the problem of user association in dynamic environments by proposing.intellig.nt user association approach,variable-reward,quality-aware Q-learning.VR-QAQL)that has an ability to strike a balance between the number of handovers per transmission and system performance whilst a g.aranteed network quality of service is *** VR-QAQL technique integ.ates the control-theoretic concepts and the reinforcement learning.approach in an LTE uplink,using.the framework of an urban vehicular *** alg.rithm is assessed using.larg.-scale simulation on a hig.way scenario at different vehicle speeds in an urban *** results demonstrate that the proposed VR-QAQL alg.rithm outperforms all the other investig.ted approaches across all mobility levels.

关键词： 5g access protocols adaptive alg.rithm control desig. dynamic rang. handover machine learning.alg.rithms multiag.nt systems radio access networks uplink user centered desig.

Decadal Variation of the Impact of La Nina on the Winter Arctic Stratosphere

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Advances in Atmospheric Sciences 2017年第5期34卷 679-684页

作者： Shuang.an YANg.tim LI Jing.ao HU Xi SHEN Key Laboratory of Meteorolog.cal Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environmental Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of lnformation Science and Technology Nanjing 210044 China International Pacific Research Center and Department of Atmospheric Sciences University of Hawaii at Manoa Honolulu Hawaii 96822 USA

The impact of La Ni?a on the winter Arctic stratosphere has thus far been an ambig.ous topic of research. Contradictory results have been reported depending.on the La Ni?a events considered. This study shows that this is mainly due to the decadal variation of La Ni?a’s impact on the winter Arctic stratosphere since the late 1970 s. Specifically,during.the period1951–78,the tropospheric La Ni?a teleconnection exhibits a typical neg.tive Pacific–North America pattern,which strong.y inhibits the propag.tion of the planetary waves from the extratropical troposphere to the stratosphere,and leads to a sig.ificantly streng.hened stratospheric polar vortex. In contrast,during.1979–2015,the La Ni?a teleconnection shifts eastwards,with an anomalous hig. concentrated in the northeastern Pacific. The destructive interference of the La Ni?a teleconnection with climatolog.cal stationary waves seen in the earlier period reduces g.eatly,which prevents the drastic reduction of planetary wave activities in the extratropical stratosphere. Corresponding.y,the stratospheric response shows a less disturbed stratospheric polar vortex in winter.

关键词： La Nina stratospheric polar vortex decadal variation planetary waves

Effect of particle shape and size on flow properties of lactose powders

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Particuolog. 2012年第2期10卷 203-208页

作者： Xiaowei Fu Deborah Huck Lisa Makein Brian Armstrong.Ulf Willen tim Freeman Freeman Technolog. I Miller Court Severn Drive Tewkesbury Gloucestershire G1208DN UK Malvern Instruments Ltd Enigma Business Park Crovewood Rd. Malvern Worcestershire WRI4 IX.Z UK

The shape and size of particles are understood to affect the bulk behaviour of powders, thoug. there are but few studies that present quantitative information on the relationship between particle shape and the flow properties of powder. This is due in part to the lack of techniques for rapidly determining.both particle shape and the rang. of flow characteristics that describe the response of powders to the stress and shear experienced during.their processing. This study presents data that quantifies the influence of particle shapeJsize of three different lactose powders on their respective flow and bulk characteristics. Two of the samples differ in size but have similar shapes; the third sample is more spherical but similar in size to one of the other two samples, The results demonstrate that in addition to particle size, particle shape sig.ificantly affect the flow characteristics of a powder over a wide rang. of stress conditions.

关键词： ParticleShapeSizePowder flowFlowability

Transmission of precise phase coherent optical sig.als using.a VCSEL stabilization system

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Optoelectronics Letters 2019年第3期15卷 200-203页

作者： Shukree Wassin g.org. Isoe Andrew Leitch tim g.bbon Centre for Broadband Communication Physics DepartmentNelson Mandela University

To improve the time and frequency reference standards used for radio astronomy and hig. precision atomic physics applications, we describe a novel stable frequency transmission technique. The approach uses a vertical-cavity surface-emitting.laser(VCSEL) based phase correction actuator. Using.a frequency mixing.process for feedback control, the phase noise induced along.the 26 km g.655 optical fibre link was actively reduced. This was achieved by using.a 1 310 nm dither controlled VCSEL phase error correction actuator tog.ther with the inherent chromatic dispersion properties of the fibre. The technique corrects phase noise and optical sig.al drift along.the fibre at the transmission end. Fractional frequency instabilities across the g.655 fibre link of 4.44×10-12 at 1 s and 4.86×10-14 at 104 s are successfully reported.

关键词： VCSEL Transmission of precise phase coherent optical sig.als using a VCSEL stabilization system

The spatial variability of actual evapotranspiration across the Amazon River Basin based on remote sensing.products validated with flux towers

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Ecolog.cal Processes 2019年第1期8卷 67-86页

作者： Victor Hug. da Motta Paca g.nzalo E.Espinoza-Dávalos tim M.Hessels Daniel Medeiros Moreira g.org.s F.Comair Wim g.M.Bastiaanssen IHE Delft Institute for Water Education Westvest 7Delft 2611 AXNetherlands TU Delft DelftNetherlands CPRM-g.olog.cal Survey of Brazil Rio de JaneiroBrazil World Bank WashingtonD.C.USA

Actual evapotranspiration(ET)is a major component of the water *** several international flux measurement prog.ams have been executed in the tropical rain forest of the Amazon,those measurements represent the evaporative process at a few selected sites *** aim of this study is to obtain the spatial distribution of ET,using.remote sensing.techniques,across the entire Amazon River *** from six g.obal ET products based on remote sensing.techniques(g.EAM,SEBS,ALEXI,CMRSET,MOD16,and SSEBop)were merg.d to obtain an ensemble prediction of the ET rates for the complex and in-accessible environment of the Amazon at a spatial resolution of 250 *** study shows that the basinwide averag. ET is 1316 mm/year with a standard deviation of 192 mm/*** new ET-Amazon product was validated ag.inst seven different historic flux tower *** energ. balance closure of the in situ measurements varied between 86 and 116%.Only months with more than 70%completeness of in situ measurements were considered for *** procedures for closure correction were included in the *** correlation between measured and remotely sensed ET is g.od(R2>0.97 for consecutive periods of 2 to 12months),and the bias correction is neg.ig.ble for the energ. balance residual method,which seemed most *** ET values have more *** monthly RMSE values vary between 7.4 and 27.8 mm/month(the averag. RMSE is 22.2mm/month),and the coefficient of determination(R2)varies between 0.48 and 0.87(the averag. R2 is 0.53).The ET from the water balance is 1380 mm/year,being.64 mm/year difference and 4.6%less than ET derived from the water *** evaporation from the Amazon basin inside Brazil is 5063 km3/year,followed by Peru with 1165 km3/***-Amazon shows more spatial details and accuracy than alternative g.obal ET products such as LandFlux-EVAL,Model Tree Ensemble(MTE),and *** justifies the development of new reg.onal ET pro

关键词： Amazon River Basin Evapotranspiration Flux towers measurements ET-Amazon product

Sperm speed is associated with sex bias of sibling. in a human population

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Asian Journal of Androlog. 2013年第1期15卷 152-154页

作者： Jim A Mossman Jon Slate tim R Birkhead Harry D Moore Allan A Pacey Department of Ecolog. and Evolutionary Biolog. Box G Brown University Providence Rhode Island 02912 USA Department of Animal and Plant Sciences University of Sheffield Western Bank Sheffield S10 2TN UK Centre for Stem Cell Biolog. Department of Biomedical Sciences University of Sheffield Western Bank Sheffield $10 2TN UK Academic Unit of Reproductive and Developmental Medicine Department of Human Metabolism School of Medicine and Biomedical Sciences Sheffield $10 2SF UK

Recent studies investig.ting.possible causes of male subfertility have larg.ly focused on how lifestyle or environmental factors impact on the process of spermatog.nesis, Markedly, fewer studies have investig.ted those risk factors that result in reduced sperm quality, such as poor sperm motility. The speed at which sperm swim is a major predictor of fertility and is extremely variable in human populations. It has been hypothesized that offspring.sex may be adaptively manipulated to maximize the offspring.s reproductive fitness （e.g., parents with g.nes for g.od male fertility traits, such as hig. sperm speed, would produce primarily sons and fewer daug.ters because the offspring.will inherit advantag.ous male fertility g.nes）. Conversely, parents with poor male fertility g.nes would produce primarily daug.ters, We tested whether there was an association between how fast a man＇s sperm swam and the sex bias of his sibling. in a sample of men attending.clinic for fertility investig.tions with their partner and with a wide rang. of semen characteristics, including.sperm speed. We found that the sex bias of a man＇s sibling. is associated with his sperm speed; men with female-biased sibling. had sig.ificantly slower sperm （judg.d using.computer-assisted sperm analysis （CASA）） than men from male-biased sibships. This observation sug.ests family composition is an important factor that needs to be considered in future eDidemiolog.cal and clinical studies of human fertility,

关键词： computer-assisted sperm analysis (CASA) fertility intralocus sexual conflict male offspring sex ratio sexual antag.nism

Machine-learned multi-system surrog.te models for materials prediction

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npj Computational Materials 2019年第1期5卷 702-707页

作者： Chandramouli Nyshadham Matthias Rupp Brayden Bekker Alexander V.Shapeev tim Mueller Conrad W.Rosenbrock g.bor Csányi David W.Wing.te g.s L.W.Hart Department of Physics and Astronomy Brigham Young UniversityProvoUT 84602USA Fritz Haber Institute of the Max Planck Society Faradayweg 4–614195 BerlinGermany Skolkovo Institute of Science and Technolog. Skolkovo Innovation CenterBuilding 3Moscow 143026Russia Department of Materials Science and Eng.neering Johns Hopkins UniversityBaltimoreMD 21218USA Eng.neering.Laboratory University of CambridgeTrumpington StreetCambridge CB21PZUK Computer Science Department Brigham Young UniversityProvoUT 84602USA Citrine Informatics 702 Marshall StreetRedwood CityCA 94063USA

Surrog.te machine-learning.models are transforming.computational materials science by predicting.properties of materials with the accuracy of ab initio methods at a fraction of the computational *** demonstrate surrog.te models that simultaneously interpolate energ.es of different materials on a dataset of 10 binary alloys(Ag.u,AlFe,AlMg.AlNi,AlTi,CoNi,CuFe,CuNi,FeV,and NbNi)with 10 different species and all possible fcc,bcc,and hcp structures up to eig.t atoms in the unit cell,15,950 structures in *** find that the deviation of prediction errors when increasing.the number of simultaneously modeled alloys isg.alg.rithms were found to qualitatively ag.ee on the prediction errors of formation enthalpy with relative errors of<2.5% for all systems.

关键词： alloys prediction CoNi

A perspective on causality assessment in epig.netic research on neurodeg.nerative disorders

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Neural Reg.neration Research 2023年第2期18卷 331-332页

作者： Philippos Koulousakis Assia Tiane Niels Helling. Jos Prickaerts Daniel van den Hove tim Vanmierlo Department of Psychiatry and Neuropsycholog. School for Mental Health and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands Department of Neuroscience Biomedical Research InstituteFaculty of Medicine and Life SciencesHasselt UniversityHasseltBelgium University MS Center(UMSC)Hasselt-Pelt HasseltBelgium Department of Immunolog. and Infection Biomedical Research InstituteFaculty of Medicine and Life SciencesHasselt UniversityHasseltBelgium Department of Psychiatry Psychosomatics and PsychotherapyUniversity of WuerzburgWuerzburgGermany

Epig.netics refers to herita ble and reversible processes reg.lating.g.ne expression that do not involve a chang. to the DNA *** modifications include DNA modifications(*** methylation a nd hydroxymethyl at ion),histo... 详细信息

关键词： deg.nerative sequence modification

ANUDEM和TIN两种建立DEM方法的对比研究

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水土保持通报 2006年第6期26卷 84-88页

作者：杨勤科 tim R.McVicar Tom g.VanNiel 李领涛中国科学院水利部水土保持研究所澳大利亚联邦科工组织水土资源研究所

针对流域水文和土壤侵蚀定量模拟分析需要,对基于TIN和Hutchinson方法建立的DEM表现地形形态和起伏的能力进行了对比研究。结果表明,基于TIN建立的DEM始终存在一些平顶现象,一些较小的侵蚀沟被忽略,其上提取的河流不完全连续,多处出现... 详细信息

针对流域水文和土壤侵蚀定量模拟分析需要,对基于TIN和Hutchinson方法建立的DEM表现地形形态和起伏的能力进行了对比研究。结果表明,基于TIN建立的DEM始终存在一些平顶现象,一些较小的侵蚀沟被忽略,其上提取的河流不完全连续,多处出现多重线条河流,因而不能如实地反映地形起伏的细部特征。而基于ANUDEM建立的DEM,其派生等高线的形状与输入等高线吻合较好,较好地表现了地形的形态和起伏,对地形和坡度的反映更加连续和光滑,其上提取的河流信息基本与地形图上的河流一致。

关键词：黄土高原数字高程模型(DEM) ANUDEM