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简介：ThepaperestablishestwostochasticSIRSmodelswithjumpstodescribethespreadofnetworkvirusbycyberwar,terrorismandothers.First,addingrandomperturbationsproportionallytoeachvariable,wegetthedynamicpropertiesaroundthepositiveequilibriumofthedeterministicmodelandtheconditionsforpersistenceandextinction.Second,givingarandomdisturbancetoendemicequilibrium,wegetastochasticsystemwithjumps.BymodifyingtheexistingLyapunovfunction,weprovethepositivesolutionofthesystemisstochasticallystable.

简介：Signalsarriveoutofphaseattheintendedreceiverfromcollaborativebeamforming（CB）nodesduetotheinstabilityintheoutputfrequencysignalsoftheuniversalsoftwareradioperipheral’s（USRP）localoscillator（LO）.Thesenodesincludingthetargetmustsynchronizetheiroscillatorfrequenciesforcoherentsignalreception.Inordertodothis,frequenciesandphasesofthesignalsshouldbeestimatedinsoftwaredefinedradio（SDR）andsmoothenwithnonlinearfilterssuchastheextendedKalmanfilter（EKF）.TheprocessnoiseparametersoftheNIUSRP-2920nodeswillhavetobecalculatedandusedwiththeEKFprocessnoisecovariancematrix.Thesenodesaregreencommunicationhardwaredeviceswheremostofthehardwareunitsarenowsoftwaredefined.ThisarticleusesthedirectspectrummethodtoobtainthephasenoisevaluesatvariousfrequencyoffsetsoftheNIUSRP-2920inordertocalculatethepowerspectraldensityoffractionalfrequencyfluctuation.Byapplyingthepower-lawnoisemodeltothisobtainedvalue,thegeneratedwhitefrequencynoiseandrandomwalkfrequencynoisevaluesareq1=1.93×10-21andq2=5.86×10-18,respectively.

简介：Predictionandvalidationoflow-frequencylinespectrumnoisefromshippropellerundernon-cavitatingconditionispresented.Theflowfieldisanalyzedwithpotential-basedpanelmethod,whichrequiresthehydrodynamicforcestobeintegratedovertheactualbladesurface,ratherthanoverthemean-chordsurface.ThenthepressuredataisusedastheinputforFfowcsWilliams-Hawkingsformulationtopredictthefarfieldacoustics.Atthesametime,propellerunsteadyforceismeasuredinhull-behindconditioninChinaLargeCavitationChannel(CLCC).Linespectrumnoiseofthe1stbladepassagefrequency(BPF)ofafive-bladedpropelleroperatinginanon-uniformflowfieldisgotaccordingtothecalculatedandmeasuredunsteadyforces,inwhichgoodagreementisobtained,andthe1stBPFnoisedifferenceiswithin3.0dB.Theinvestigationrevealsthatpredictionprecisionofthepropeller’s1stBPFunsteadyforcewithpanelmethodhavereachedengineeringpracticaldegree,providingsignificantparametersforpredictionofpropellerlinespectrumnoise.

简介：Thenoisedatainverticalcomponentrecordsof85seismicstationsinFujianProvinceduring2012isusedastheresearchobjectinthispaper.Thenoisedataisdividedintofiveminutesegmentstocalculatethepowerspectra.Thehighreferencelineandlowreferencelineofstationarethenidentifiedbydrawingaprobabilitydensityfunctiongraph(PDF)usingthepowerspectralprobabilitydensityfunction.Moreover,accordingtotheanomaliesofPDFgraphsin85seismicstations,theabnormalnoiseisdividedintofourcategories:droppedpacket,lownoise,highnoise,andmediannoiseanomalies.Afterwards,fourselectionmethodsarefoundbythehighorlownoisereferencelineofthestations,andthesystemofreal-timemonitoringofseismicnoiseisformedbycombiningthefourselectionmethods.Noiserecordsof85seismicstationsinFujianProvinceinJuly2013areselectedforverification,andtheresultsshowthattheanomalousnoise-recognitionsystemcouldreacha90%successrateatmoststationsandtheeffectofselectionareverygood.Therefore,itcouldbeappliedtotheseismicnoisereal-timemonitoringinstations.

简介：Wecomprehensivelycharacterizethetransmissionperformanceofm-aryquadratureamplitudemodulation（m-QAM）signalsthroughasiliconmicroringresonatorintheexperiment.Usingorthogonalfrequency-divisionmultiplexingbasedonoffsetQAM（OFDM/OQAM）whichismodulatedwithm-QAMmodulations,wedemonstratelow-penaltydatatransmissionofOFDM/OQAM64-QAM,128-QAM,256-QAM,and512-QAMsignalsinasiliconmicroringresonator.Theobservedopticalsignal-to-noiseratio（OSNR）penaltiesare1.7dBfor64-QAM,1.7dBfor128-QAM,and3.1dBfor256-QAMatabit-errorrate（BER）of2×10-3and3.3dBfor512-QAMataBERof2×10-2.Theperformancedegradationduetothewavelengthdetuningfromthemicroringresonanceisevaluated,showingawavelengthrangeof0.48nmwithBERbelow2×10-3.Moreover,wedemonstratedatatransmissionof191.2-Gbit/ssimultaneouseightwavelengthchannelOFDM/OQAM256-QAMsignalsinasiliconmicroringresonator,achievingOSNRpenaltieslessthan2dBataBERof2×10-2.

简介：摘要目的调查分析甲状腺疾病构成比率及发病相关因素。方法选择2014年1月-2016年1月在我院体检科进常规体检人员2342例，检查发现患甲状腺疾病且转介至我院内分泌科就诊的患者259例，调查甲状腺疾病构成比率，采用自制问卷调查,回顾性分析甲状腺疾病发病相关因素。结果在甲状腺疾病中，甲状腺功能亢进102例（39.4%），甲状腺功能减低74例（28.6%），甲状腺结节63例（24.3%），其中甲状腺癌2例（0.7%），自身免疫性甲状腺炎6例（2.3%），亚急性甲状腺炎14例（5.4%）。甲状腺疾病与性别、年龄、饮食习惯、心理压力、烟酒嗜好、甲状腺疾病病史、收入水平、环境因素等方面具有显著相关性（P＜0.05）。结论甲状腺疾病发病原因与多种因素有关，其中女性、中青年、有甲状腺疾病家族史、频繁摄入高碘食品、心理压力大、有烟酒不良嗜好、高收入、长期接触理化污染环境是甲状腺疾病的易感人群，研究其相关因素对于甲状腺疾病的病因预防、早期诊断、早期合理治疗均具有重要意义。

简介：Inordertoimprovetheperformanceoflinespectrumdetection,accordingtothefeaturethattheunderwatertargetradiatednoisecontainingstablelinespectrum,thedifferencesofthephasedifferencebetweenlinespectrumandbackgroundnoise,aweightedlinespectrumdetectionalgorithmbasedonthephasevarianceisproposedinfrequencydomain.Afterphasedifferencealignment,thephasevarianceoflinespectrumandthephaseofbackgroundnoise,respectively,aresmallandbiginfrequencydomain,thismethodutilizestheweightedstatisticalalgorithmtocumulatethefrequencyspectrumbasedonthephasevariance,whichcanrestrainthebackgroundnoisedisturbance,andenhancethesignaltonoiseratio(SNR).Thetheoryanalysisandexperimentalresultsbothverifythattheproposedmethodcanwellenhancetheenergyoflinespectrum,restraintheenergyofbackgroundnoise,andhavebetterdetectionperformanceunderlowerSNR.

简介：Parameterestimationofsignalsofuniversalsoftwareradioperipheral(USRP)devicesiscrucialtosolvetheproblemofphaseoffsetsofreceivedsignalsindistributedbeamforming.Forsystemsthatwillutilizetheclosedloopfeedbackalgorithmwherethereceiverneedstosendthereceivedsignalstrength(RSS)valuesperiodicallytothebeamformingnodesoastotakeadvantageofenergyconservation,thefrequencyandphaseofthesesignalsshouldbeestimatedbeforesmootheningbynonlinearfilters.ThisarticlepresentstheestimationofthefrequencyoffsetsofaGaussianminimumshiftkeying(GMSK)signalfromN210USRPdevicesinrealtimebyusingtheRadix-2fastFouriertransform(FFT)algorithminGNURadio.Forthesegreencommunicationsdevices,mostoftheneededhardwarepartshavebeensoftwaredefined,therebyreducingthesupposedenergyconsumption.Thefrequencyoffsetsfromreferencecarrierfrequenciesof900MHzand2.4GHzarelessthan3kHzeachbeforetheestimation,buttheaverageoffsetsare45Hzand100Hzaftertheestimation,respectively.Thehighoffsetvalueexperiencedwiththe2.4GHzcarrierwasduetoconsistentinterferencefromdevicesonthatsamefrequency.

简介：摘要目的探讨X线胸片心胸比率诊断心力衰竭的临床价值。方法以我院2015年~2016年11月收治的呼吸困难患者120例按照超声心动图诊断结果并结合临床资料将其分为心衰竭组62例以及非心衰竭组58例，对全部患者行X线胸片心胸比率诊断，对其诊断结果进行观察。结果X线胸片心胸比率诊断心力衰竭准确性、敏感性以及特异性患者分别为90%、87.1%以及93.10%；心力衰竭组62例患者中，通过X线胸片心胸比率诊断后发现，6例患者存在肺泡性肺水肿（9.7%），16例患者存在胸腔积液（25.81%），38例患者存在间质肺水肿（61.29%），47例患者存在心影增大（75.81%），49例患者存在肺静脉高压（79.03%）。结论X线胸片心胸比率诊断心力衰竭患者准确性较高，因此该种诊断技术值得在临床上大力推广使用。

简介：根据有0.5的一个空间决定的每日的降水和温度的二gridded数据集

简介：文章探讨了中位数排序集抽样下总体均值比率估计的方法。通过对不同抽样方法的估计量进行效率对比,证明在总体分布为正态分布的情况下,基于中位数排序集样本的比率估计比随机抽样的样本比率估计效率高。

简介：这篇论文为变化时间的趋于增加的噪音调查稳定的一个基本问题随机的系统。一个必要、足够的稳定条件基于后退的地平线途径被介绍。如果条件满足，明确的变化时间的控制器被设计。介绍结果就我们的知识而言是新的。

简介：WeuseddatafromtheXinjiangDigitalSeismicNetworkandPSD(PowerSpectralDensity)methodtoperformnoiselevelassessmentforsixstations.Wecalculatedthemedianofthepowerspectraldensitytoevaluatethenoiselevelofdifferentstations.Afterthecomparisonofthepowerspectraldensityofdifferentstationsandtheairgunsignalrecognition,wefoundthatnoiselevelofstationswithrecognizableairgunsourcesignalsislowerthanthatofstationswithoutrecognizablesignals.Thelargestdifferenceofthepowerspectraldensityis40dB,andthesmallestis15dB.Finally,wefoundthatthefailuretorecognizethesignalofairgunsourcesatsomestationsisduetothenoiselevel.

简介：ThispapersummarizesthebasicsituationoftheBinchuanTransmittingSeismicStationandthegeophysicalobservationsoftheareawhereitislocated,withafocusontheconstitutionoftheobservationsystemofthetransmittingseismicstation,theexcitationcharacteristicsandpropagationdistanceofsignalsexcitedbytheairgunsourceinthereservoirandwell.ThepaperalsosummarizesanddiscussesontheresultsoftheobservationsandproblemsencounteredsincetheTransmittingSeismicStationwasbuilt.Finally,thispaperproposesthemainresearchtobecarriedoutonthebasisoftheprojectaims.

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简介：Thisworkdevelopsnear-optimalcontrolsforsystemsgivenbydifferentialequationswithwidebandnoiseandrandomswitching.Therandomswitchingismodeledbyacontinuous-time,time-inhomogeneousMarkovchain.Underbroadconditions,itisshownthatthereisanassociatedlimitproblem,whichisaswitchingjumpdiffusion.Usingnear-optimalcontrolsofthelimitsystem,wethenbuildcontrolsfortheoriginalsystems.Itisshownthatsuchconstructedcontrolsarenearlyoptimal.

简介：摘要目的探讨中性粒细胞/淋巴细胞比值（NLR）、血小板计数与非小细胞肺癌（NSCLC）患者预后的关系。方法回顾性分析154例晚期NSCLC临床病理资料，以NLR均值为临界值，将患者分为低NLR组和高NLR组，分析NLR与NSCLC临床病理特征关系及预后的变化。结果NLR与肺癌病理类型、ECOG评分、血小板计数有关(P＜0.05)，住院死亡组NLR值更高。结论NLR越高，NSCLC患者住院死亡率越高，NLR对判断NSCLC患者的病情危险性及预后有着重要价值。

简介：本文使用我国上市公司数据,从信贷人员行为视角出发,实证检验了在银行短期信贷决策中,信贷人员对企业流动比率的使用方式是否受货币政策及所有权性质因素的影响。研究结果表明:在货币政策宽松时期,信贷人员对企业流动比率的要求较低,而在货币政策紧缩时期,则对企业流动比率的要求较高;考虑企业所有权性质影响时,与国有企业相比,信贷人员更加关注民营企业的流动比率且要求更高。信贷人员在短期信贷决策中对会计信息的使用方式不同,会给银行带来很大的信贷风险,银行应采取相关措施对信贷人员的行为予以监督规范。

简介：Amode-lockedthulium-dopedfiberlaser(TDFL)basedonnonlinearpolarizationrotation(NPR)withdifferentnetanomalousdispersionisdemonstrated.Whenthecavitydispersionis-1.425ps~2,thenoise-like(NL)pulsewithcoherencespikewidthof406fsandpulseenergyof12.342nJisgeneratedatacenterwavelengthof2003.2nmwith3dBspectralbandwidthof23.20nm.Intheexperimentalperiodof400min,the3dBspectralbandwidthvariation,theoutputpowerfluctuation,andthecentralwavelengthshiftarelessthan0.06nm,0.04dB,and0.4nm,respectively,indicatingthattheNPR-basedTDFLoperatingintheNLregimeholdsgoodlong-termstability.