简介：Ananti-interferenceorthogonalcodingisintroducedbasedonHadamardcodeandOrthogonalFrequency-DivisionMultiplexing(OFDM),inwhichallsub-channelsofUltra-WideBand(UWB)systemaredividedintoMsub-bandsandthepoweroftheeverytransmittedsymbolspreadsovereachofthesub-bandsratherthanonesub-band.Thecompletemathematicalanalyticalrelationbetweenencodinganddecodingispresentandtherobustnessofthesystemtointerferenceisexamined.Whensomesub-channelsareaffectedbyinterferenceorjamming,thesystemcouldregeneratethesymbolfromothers.SimulationresultsshowthattheAnti-InterferenceUWB-OFDM(AI-OFDM)systemhasevidentadvantagesoverconventionalUWB-OFDMsystemsaswellastheInterferenceSuppressingUWB-OFDM(IS-OFDM)inBitErrorRate(BER)thankstoitsrobustnesstointerference.Inthecaseofbadinterference,theAI-OFDMsystemcouldworkuptosnuffwithoutanyanti-interferencestep,buttheconventionalUWB-OFDMsystemcouldn't.ComparedwiththeIS-OFDMsystem,theAI-OFDMsystemimprovestheperformanceabout5dBinSignal-to-InterferenceRatio(SIR)andtheorderof1～2inBER.

简介：Thispaperpresentsanoveltrustmodelbasedonmultipledecisionfactortheory(MDFT)andatrustroutingalgorithmbasedonMDFTtoexactlyevaluateroutingnodetrustandestablishatrustworthyroutingpath.MDFTintegratesfourdimensionaltrustdecisionfactorsincludingbehavior,state,recommendandnodelivenesstorealizeanexactlyfiner-grainedtrustevaluation.OnthebasisofMDFT,atrustroutingalgorithmispresentedandvalidatedinopenshortestpathfirst(OSPF)protocol.Simulationresultsshowthatthealgorithmcanreflecttheroutingnodetrustaccuratelyandhasbetterdynamicresponseability.Underthecircumstanceofexistingdeceptivenodes,thealgorithmhasbetteranti-deceptionperformanceandhigherattacknodedetectionratethanconventionalalgorithm.

简介：文章提出了一种基于FP-Growth算法的高校学生学业预警系统,能够根据以往的学生成绩信息挖掘出不及格课程间的关联规则,以提前给学生发出课程预警。首先从现有的学生成绩系统中筛选并构造出学生不及格课程事务数据库;然后运用FP-Growth算法进行课程关联规则挖掘;最后利用关联规则,自动发现学生将来可能存在危险的课程,并结合现在的学习成绩发出学业预警。经验证,本方法对学生成绩的预警有较高的准确率,并可推广应用到学生工作的其他方面。