Abstract Information Gathering Support Interface by the Overview Presentation of Web Search
99年考研英语真题(张剑)
1999年年全真试题PartⅠClozeTestDirections：Foreachnumberedblankinthefollowingpassage,therearefourchoicesmarked［A］,［B］,［C］and ［D］.ChoosethebestoneandmarkyouransweronANSWERSHEET1byblackeningthecorrespondingletterinthebr acketswithapencil.(10points)panies1lowaccidentratesplantheirsafetyprograms,workhardtoorgani zethem,andcontinueworkingtokeepthem2andactive.Whentheworkiswelldone,a3ofaccidentfreeoperationsisestablished4timelostduetoinjuriesiskeptataminimum.Successfulsafetyprogramsmay5greatlyintheemphasisplacedoncertainaspectsoftheprogram.Someplacegreat emphasisonmechanicalguarding.Othersstresssafeworkpracticesby6rulesorregulations.7othersdependonanemotio nalappealtotheworker.But,therearecertainbasicideasthatmustbeusedineveryprogramifmaximumresultsaretobeobt ained.Therecanbenoquestionaboutthevalueofasafetyprogram.Fromafinancialstandpointalone,safety8.Thefewerth einjury9,thebettertheworkman’sinsurancerate.Thismaymeanthedifferencebetweenoperatingat10orataloss.1.［A］at ［B］in ［C］on ［D］with2.［A］alive ［B］vivid ［C］mobile ［D］diverse3.［A］regulation ［B］climate ［C］circumstance ［D］requirement4.［A］where ［B］how ［C］what ［D］unless5.［A］alter ［B］differ ［C］shift ［D］distinguish6.［A］constituting ［B］aggravating ［C］observing ［D］justifying7.［A］Some ［B］Many ［C］Even ［D］Still8.［A］comesoff ［B］turnsup ［C］paysoff ［D］holdsup9.［A］claims ［B］reports ［C］declarations ［D］proclamations10.［A］anadvantage ［B］abenefit ［C］aninterest ［D］aprofitPartⅡReadingComprehensionDirections:Eachofthepassagesbelowisfollowedbysomequestions.Foreachquestiontherearefouranswersmarked［A］,［B］,［C］and［D］.Readthepassagescarefullyandchoosethebestanswertoeachofthequestions.ThenmarkyouransweronANSW ERSHEET1byblackeningthecorrespondingletterinthebracketswithapencil.(40points)Passage1It’saroughworldoutthere.Stepoutsideandyoucouldbreakalegslippingonyourdoormat.Lightupthestoveandyou couldburndownthehouse.Luckily,ifthedoormatorstovefailedtowarnofcomingdisaster,asuccessfullawsuitmightco mpensateyouforyourtroubles.Orsothethinkinghasgonesincetheearly1980s,whenjuriesbeganholdingmorecompani esliablefortheircustomers’misfortunes.Feelingthreatened,companiesrespondedbywritingeverlongerwarninglabels,tryingtoanticipateeverypossibleaccident.Today,stepladderscarrylabelsseveralincheslongtha twarn,amongotherthings,thatyoumight—surprise!—falloff.Thelabelon achild’sBatmancapecautionsthatthetoy“doesnotenableusertofly”.Whilewarningsareoftenappropriateandnecessary—thedangersofdruginteractions,forexample—andmanyare requiredbystateorfederal regulations,itisn’tclearthattheyactuallyprotectthemanufacturersandsellersfromliabilityif acustomerisinjured.About50percentofthecompanieslosewheninjuredcustomerstakethemtocourt.Nowthetideappearstobeturning.Aspersonalinjuryclaimscontinueasbefore,somecourtsarebeginningtosidewit hdefendants,especiallyincaseswhereawarninglabelprobablywouldn’thavechangedanything.InMay,JulieNimmon s,presidentofSchuttSportsinIllinois,successfullyfoughtalawsuitinvolvingafootballplayerwhowasparalyzedinaga mewhilewearingaSchutthelmet.“We’rereallysorryhehasbecomeparalyzed,buthelmetsaren’tdesignedtopreventtho sekindsofinjuries,”saysNimmons.Thejuryagreedthatthenatureofthegame,notthehelmet,wasthereasonfortheathlet e’sinjury.Atthesametime,theAmericanLawInstitute—agroupofjudges,lawyers,andacademicswhoserecommendat ionscarrysubstantialweight—issuednewguidelinesfortortlawstatingthatcompaniesneednotwarncustomersofobvio usdangersorbombardthemwithalengthylistofpossibleones.“Importantinformationcangetburiedinaseaoftrivialities ,”saysalawprofessoratCornellL awSchoolwhohelpeddraftthenewguidelines.Ifthemoderateendofthelegalcommuni tyhasitsway,theinformationonproductsmightactuallybeprovidedforthebenefitofcustomersandnotasprotectionagai nstlegalliability.11.Whatwerethingslikein1980swhenaccidentshappened?［A］Customersmightberelievedoftheirdisastersthroughlawsuits.［B］Injuredcustomerscouldexpectprotectionfromthelegalsystem.［C］Companieswouldavoidbeingsuedbyprovidingnewwarnings.［D］Juriestendedtofindfaultwiththecompensationscompaniespromised.12.Manufacturersasmentionedinthepassagetendto.［A］satisfycustomersbywritinglongwarningsonproducts［B］becomehonestindescribingtheinadequaciesoftheirproducts［C］makethebestuseoflabelstoavoidlegalliability［D］feelobligedtoviewcustomers’safetyastheirfirstconcern13.ThecaseofSchutthelmetdemonstratedthat.［A］someinjuryclaimswerenolongersupportedbylaw［B］helmetswerenotdesignedtopreventinjuries［C］productlabelswouldeventuallybediscarded［D］somesportsgamesmightlosepopularitywithathletes14.Theauthor’sattitudetowardstheissueseemstobe.［A］biased ［B］indifferent ［C］puzzling ［D］objectivePassage2InthefirstyearorsoofWebbusiness,mostoftheactionhasrevolvedaroundeffortstotaptheconsumermarket.Morer ecently,astheWebprovedtobemorethanafashion,companieshavestartedtobuyandsellproductsandserviceswithonea nother.Suchbusiness to businesssalesmakesensebecausebusinesspeopletypicallyknowwhatproductthey’relookingfor.Nonetheless,manycompaniesstillhesitatetousetheWebbecauseofdoubtsaboutitsreliability.“Businessesneedt ofeeltheycantrustthepathwaybetweenthema ndthesupplier,”sayssenioranalystBlaneErwinofForresterResearch.So mecompaniesarelimitingtheriskbyconductingonlinetransactionsonlywithestablishedbusinesspartnerswhoaregive naccesstothecompany’sprivateintranet.AnothermajorshiftinthemodelforInternetcommerceconcernsthetechnologyavailableformarketing.Untilrece ntly,Internetmarketingactivitieshavefocusedonstrategiesto“pull”customersintosites.Inthepastyear,however,softw arecompanieshavedevelopedtoolsthatallowcompaniesto“push”informationdirectlyouttoconsumers,transmitt ing marketingmessagesdirectlytotargetedcustomers.Mostnotably,thePointcastNetworkusesascreensavertodeliveracontinuallyupdatedstreamofnewsandadvertisementstosubscribers’computermonitors.Subscriberscancustomizethei nformationtheywanttoreceiveandproceeddirectlyt oacompany’paniessuchasVirtualVineyardsareal readystartingtousesimilartechnologiestopushmessagestocustomersaboutspecialsales,productofferings,orotherev ents.ButpushtechnologyhasearnedthecontemptofmanyWebusers.Onlineculturethinkshighlyofthenotionthattheinf ormationflowingontothescreencomestherebyspecificrequest.Oncecommercialpromotionbeginstofillthescreenuni nvited,thedistinctionbetweentheWebandtelevisionfades.That’saprospectthathorrifiesNetpurists.ButitishardlyinevitablethatcompaniesontheWebwillneedtoresorttopushstrategiestomakemoney.Theexampl esofVirtualVineyards,,andotherpioneersshowthataWebsitesellingtherightkindofproductswiththerig htmixofinteractivity,hospitality,andsecuritywillattractonlinecustomers.Andthecostofcomputingpowercontinuest ofreefall,whichisagoodsignforanyenterprisesettingupshopinsilicon.Peoplelookingback5or10yearsfromnowmay wellwonderwhysofewcompaniestooktheonlineplunge.15.WelearnfromthebeginningofthepassagethatWebbusiness.［A］hasbeenstrivingtoexpanditsmarket［B］intendedtofollowafancifulfashion［C］triedbutinvaintocontrolthemarket［D］hasbeenboomingforoneyearorso16.Speakingoftheonlinetechnologyavailableformarketing,theauthorimpliesthat.［A］thetechnologyispopularwithmanyWebusers［B］businesseshavefaithinthereliabilityofonlinetransactions［C］thereisaradicalchangeinstrategy［D］itisaccessiblelimitedlytoestablishedpartners17.IntheviewofNetpurists,.［A］thereshouldbenomarketingmessagesinonlineculture［B］moneymakingshouldbegivenprioritytoontheWeb［C］theWebshouldbeabletofunctionasthetelevisionset［D］thereshouldbenoonlinecommercialinformationwithoutrequests18.Welearnfromthelastparagraphthat.［A］pushinginformationontheWebisessentialtoInternetcommerce［B］interactivity,hospitalityandsecurityareimportanttoonlinecustomers［C］leadingcompaniesbegantotaketheonlineplungedecadesago［D］settingupshopsinsiliconisindependentofthecostofcomputingpowerPassage3Aninvisibleborderdividesthosearguingforcomputersintheclassroomonthebehalfofstudents’careerprospectsa ndthosearguingforcomputersintheclassroomforbroaderreasonsofradicaleducationalreform.Veryfewwritersonthes ubjecthaveexploredthisdistinction—indeed,contradiction—whichgoestotheheartofwhatiswrongwiththecampaig ntoputcomputersintheclassroom.Aneducationthataimsatgettingastudentacertainkindofjobisatechnicaleducation,justifiedforreasonsradicallyd ifferentfromwhyeducationisuniversallyrequiredbylaw.Itisnotsimplytoraiseeveryone’sjobprospectsthatallchildre narelegallyrequiredtoattendschoolintotheirteens.Rather,wehaveacertainconceptionoftheAmericancitizen,acharac terwhoisincompleteifhecannotcompetentlyassesshowhislivelihoodandhappinessareaffectedbythingsoutsideofhi mself.Butthiswasnotalwaysthecase;beforeitwaslegallyrequiredforallchildrentoattendschooluntilacertainage,itwa swidelyacceptedthatsomewerejustnotequippedbynaturetopursuethiskindofeducation.Withoptimismcharacteristi cofallindustrializedcountries,putereducationadvocatesforsakethisoptimisticnotionforapessimismthatbetraystheirotherwisecheeryoutlook.Bankingontheconfusionbetweeneducationalandvocationalreasonsforbringingcomputersintoschools,computeredadvocates oftenemphasizethejobprospectsofgraduatesovertheireducationalachievement.Therearesomegoodargumentsforatechnicaleducationgiventherightkindofstudent.ManyEuropeanschoolsintr oducetheconceptofprofessionaltrainingearlyoninordertomakesurechildrenareproperlyequippedfortheprofessions theywanttojoin.Itis,however,presumptuoustoinsistthattherewillonlybesomanyjobsforsomanyscientists,somanyb usinessmen,somanyaccountants.Besides,thisisunlikelytoproducetheneedednumberofeverykindofprofessionalina countryaslargeasoursandwheretheeconomyisspreadoversomanystatesandinvolvessomanyinternationalcorporatio ns.But,forasmallgroupofstudents,professionaltrainingmightbethewaytogosincewelldevelopedskills,allotherfactorsbeingequal,canbethedifferencebetweenhavingajobandnot.Ofcourse,thebasicsofus inganycomputerthesedaysareverysimple.Itdoesnottakealifelongacquaintancetopickupvarioussoftwareprograms.I fonewantedtobecomeacomputerengineer,thatis,ofcourse,anentirelydifferentstory.Basiccomputerskillstake—atth everylongest—acoupleofmonthstolearn.Inanycase,basiccomputerskillsareonlycomplementarytothehostofrealski llsthatarenecessarytobecominganykindofprofessional.Itshouldbeobserved,ofcourse,thatnoschool,vocationalorno t,ishelpedbyaconfusionoveritspurpose.19.Theauthorthinksthepresentrushtoputcomputersintheclassroomis.［A］far reaching ［B］dubiouslyoriented［C］self contradictory ［D］radicallyreformatory20.Thebeliefthateducationisindispensabletoallchildren.［A］isindicativeofapessimismindisguise［B］cameintobeingalongwiththearrivalofcomputers［C］isdeeplyrootedinthemindsofcomputer edadvocates［D］originatedfromtheoptimisticattitudeofindustrializedcountries21.Itcouldbeinferredfromthepassagethatintheauthor’scountrythe Europeanmodelofprofessionaltrainingis.［A］dependentuponthestartingageofcandidates［B］worthtryinginvarioussocialsections［C］oflittlepracticalvalue［D］attractivetoeverykindofprofessional22.Accordingtotheauthor,basiccomputerskillsshouldbe.［A］includedasanauxiliarycourseinschool［B］highlightedinacquisitionofprofessionalqualifications［C］masteredthroughalife longcourse［D］equallyemphasizedbyanyschool,vocationalorotherwisePassage4WhenaScottishresearchteamstartledtheworldbyrevealing3monthsagothatithadclonedanadultsheep,Presiden tClintonmovedswiftly.Declaringthathewasopposedtousingthisunusualanimalhusbandrytechniquetoclonehumans ,heorderedthatfederalfundsnotbeusedforsuchanexperiment—althoughnoonehadproposedtodoso—andaskedanin dependentpanelofexpertschairedbyPrincetonPresidentHaroldShapirotoreportbacktotheWhiteHousein90dayswit hrecommendationsforanationalpolicyonhumancloning.Thatgroup—theNationalBioethicsAdvisoryCommission(NBAC)—hasbeenworkingfeverishlytoputitswisdomonpaper,andatameetingon17May,membersagreedonanearfinaldraftoftheirrecommendations.NBACwillaskthatClinton’s90daybanonfederalfundsforhumancloningbeextendedindefinitely,andpossiblythatitbemadelaw.ButNBACmembersareplanningtowordtherecommendationnarrowlytoavoidnewrestrictionsonresearchthatinvolvesthecloningofhuma nDNAorcells—routineinmolecularbiology.Thepanelhasnotyetreachedagreementonacrucialquestion,however,wh ethertorecommendlegislationthatwouldmakeitacrimeforprivatefundingtobeusedforhumancloning.Inadraftprefacetotherecommendations,discussedatthe17Maymeeting,Shapirosuggestedthatthepanelhadfoun dabroadconsensusthatitwouldbe“morallyunacceptabletoattempttocreateahumanchildbyadultnuclearcloning.”Sha piroexplainedduringthemeetingthatthemoraldoubtstemsmainlyfromfearsabouttherisktothehealthofthechild.Thep aneltheninformallyacceptedseveralgeneralconclusions,althoughsomedetailshavenotbeensettled.NBACplanstocallforacontinuedbanonfederalgovernmentfundingforanyattempttoclonebodycellnucleitocrea teachild.Becausecurrentfederallawalreadyforbidstheuseoffederalfundstocreateembryos(theearlieststageofhuman offspringbeforebirth)forresearchortoknowinglyendangeranembryo’slife,NBACwillremainsilentonembryoresear ch.NBACmembersalsoindicatedthattheywouldappealtoprivatelyfundedresearchersandclinicsnottotrytocloneh umansbybodycellnucleartransfer.Buttheyweredividedonwhethertogofurtherbycallingforafederallawthatwouldim poseacompletebanonhumancloning.Shapiroandmostmembersfavoredanappealforsuchlegislation,butinaphoneint erview,hesaidthisissuewasstill“upintheair”.23.Wecanlearnfromthefirstparagraphthat.［A］federalfundshavebeenusedinaprojecttoclonehumans［B］theWhiteHouserespondedstronglytothenewsofcloning［C］NBACwasauthorizedtocontrolthemisuseofcloningtechnique［D］theWhiteHousehasgotthepanel’srecommendationsoncloning24.Thepanelagreedonallofthefollowingexceptthat.［A］thebanonfederalfundsforhumancloningshouldbemadealaw［B］thecloningofhumanDNAisnottobeputundermorecontrol［C］itiscriminaltouseprivatefundingforhumancloning［D］itwouldbeagainstethicalvaluestocloneahumanbeing25.NBACwillleavetheissueofembryoresearchundiscussedbecause.［A］embryoresearchisjustacurrentdevelopmentofcloning［B］thehealthofthechildisnotthemainconcernofembryoresearch［C］anembryo’slifewillnotbeendangeredinembryoresearch［D］theissueisexplicitlystatedandsettledinthelaw26.Itcanbeinferredfromthelastparagraphthat.［A］someNBACmembershesitatetobanhumancloningcompletely［B］alawbanninghumancloningistobepassedinnotime［C］privatelyfundedresearcherswillrespondpositivelytoNBAC’sappeal［D］theissueofhumancloningwillsoonbesettledPassage5Science,inpractice,dependsfarlessontheexperimentsitpreparesthanonthepreparednessofthemindsofthemenw howatchtheexperiments.SirIsaacNewtonsupposedlydiscoveredgravitythroughthefallofanapple.Appleshadbeenfa llinginmanyplacesforcenturiesandthousandsofpeoplehadseenthemfall.ButNewtonforyearshadbeencuriousaboutt hecauseoftheorbitalmotionofthemoonandplanets.Whatkepttheminplace?Whydidn’ttheyfalloutofthesky?Thefactt hattheapplefelldowntowardtheearthandnotupintothetreeansweredthequestionhehadbeenaskinghimselfaboutthose largerfruitsoftheheavens,themoonandtheplanets.Howmanymenwouldhaveconsideredthepossibilityofanapplefallingupintothetree?Newtondidbecausehewas nottryingtopredictanything.Hewasjustwondering.Hismindwasreadyfortheunpredictable.Unpredictabilityispartoftheessentialnatureofresea rch.Ifyoudon’thaveunpredictablethings,youdon’thaveresearch.Scientiststendtoforgetthi swhenwritingtheircutanddriedreportsforthetechnicaljournals,buthistoryisfilledwithexamplesofit.Intalkingtosomescientists,particularlyyoungerones,youmightgathertheimpression thattheyfindthe“scientific method”asubstituteforimaginativethought.I’veattendedresearchconferenceswhereascientisthasbeenaskedwhathe thinksabouttheadvisabilityofcontinuingacertainexperiment.Thescientisthasfrowned,lookedatthegraphs,andsaid,“thedataarestillinco nclusive.”“Weknowthat,”themenfromthebudgetofficehavesaid,“butwhatdoyouthink?Isitwort hwhilegoingon?Whatdoyouthinkwemightexpect?”Thescientisthasbeenshockedathavingevenbeenaskedtospecula te.Whatthisamountsto,ofcourse,isthatthescientisthasbecomethevictimofhisownwritings.Hehasputforwardunq uestionedclaimssoconsistentlythathenotonlybelievesthemhimself,buthasconvincedindustrialandbusinessmanage mentthattheyaretrue.Ifexperimentsareplannedandcarriedoutaccordingtoplanasfaithfullyasthereportsinthesciencej ournalsindicate,thenitisperfectlylogicalformanagementtoexpectresearchtoproduceresultsmeasurableindollarsand cents.Itisentirelyreasonableforauditorstobelievethatscientistswhoknowexactlywheretheyaregoingandhowtheywi llgetthereshouldnotbedistractedbythenecessityofkeepingoneeyeonthecashregisterwhiletheothereyeisonthemicros cope.Nor,ifregularityandconformitytoastandardpatternareasdesirabletothescientistasthewritingofhispaperswould appeartoreflect,ismanagementtobeblamedfordiscriminatingagainstthe“oddballs”amongresearchersinfavorofm or econventionalthinkerswho“workwellwiththeteam”.27.TheauthorwantstoprovewiththeexampleofIsaacNewtonthat.［A］inquiringmindsaremoreimportantthanscientificexperiments［B］scienceadvanceswhenfruitfulresearchesareconducted［C］scientistsseldomforgettheessentialnatureofresearch［D］unpredictabilityweighslessthanpredictioninscientificresearch28.Theauthorassertsthatscientists.［A］shouldn’treplace“scientificmethod”withimaginativethought［B］shouldn’tneglecttospeculateonunpredictablethings［C］shouldwritemoreconcisereportsfortechnicaljournals［D］shouldbeconfidentabouttheirresearchfindings29.Itseemsthatsomeyoungscientists.［A］haveakeeninterestinprediction［B］oftenspeculateonthefuture［C］thinkhighlyofcreativethinking［D］stickto“scientificmethod”30.Theauthorimpliesthattheresultsofscientificresearch.［A］maynotbeasprofitableastheyareexpected［B］canbemeasuredindollarsandcents［C］relyonconformitytoastandardpattern［D］aremostlyunderestimatedbymanagementPartⅢEnglish ChineseTranslationDirections:ReadthefollowingpassagecarefullyandthentranslatetheunderlinedsegmentsintoChinese.Yourtranslationmus tbewrittenclearlyonANSWERSHEET2.(15points)31）Whiletherearealmostasmanydefinitionsofhistoryastherearehistorians,modernpracticemostcloselyconformstoonet hatseeshistoryastheattempttorecreateandexplainthesignificanteventsofthepast.Caughtinthewebofitsowntimeandplace,eachgenerationofhistoriansdeterminesanewwhatissignificantforitinthepast.Inthissearchtheevidencefoundisa lwaysincompleteandscattered;itisalsofrequentlypartialorpartisan.Theironyofthehi storian’scraftisthatitspractition ersalwaysknowthattheireffortsarebutcontributionstoanunendingprocess.32）Interestinhistoricalmethodshasarisenlessthroughexternalchallengetothevalidityofhistoryasanintellectualdisciplin eandmorefrominternalquarrelsamonghistoriansthemselves.Whilehistoryoncerevereditsaffinitytoliteratureandphi losophy,theemergingsocialsciencesseemedtoaffordgreateropportunitiesforaskingnewquestionsandprovidingrew ardingapproachestoanunderstandingofthepast.Socialsciencemethodologieshadtobeadaptedtoadisciplinegoverne dbytheprimacyofhistoricalsourcesratherthantheimperativesofthecontemporaryworld.33）Duringthistransfer,traditionalhistoricalmethodswereaugmentedbyadditionalmethodologiesdesignedtointerpretth enewformsofevidenceinthehistoricalstudy.Methodologyisatermthatremainsinherentlyambiguousinthehistoricalprofession.34）Thereisnoagreementwhethermethodologyreferstotheconceptspeculiartohistoricalworkingeneralortotheresearcht echniquesappropriatetothevariousbranchesofhistoricalinquiry.Historians,especiallythosesoblindedbytheirresearc hintereststhattheyhavebeenaccusedof“tunnelmethod,”frequentlyfallvictimtothe“technicalfallacy.”Alsocommoni nthenaturalsciences,thetechnicistfallacymistakenlyidentifiesthedisciplineasawholewithcertainpartsofitstechnical implementation.35）Itappliesequallytotraditionalhistorianswhoviewhistoryasonlytheexternalandinternalcriticismofsources,andtosoci alsciencehistorianswhoequatetheiractivitywithspecifictechniques.SectionⅣWriting(15points)36.Directions:A.Studythefollowinggraphscarefullyandwriteanessayinatlessthan150words.B.YouressaymustbewrittenclearlyontheANSWERSHEET2.C.Youressayshouldcoverthreepoints:a.effectofthecountry’sgrowinghumanpopulationonitswildlife,b.possiblereasonsfortheeffect,c.yoursuggestionforwildlifeprotection试题精解PartⅠClozeTest一、文章总体分析本文是围绕安全生产这个话题的一篇论证性文章。
信息安全概论课后答案
四45五3六57十4十一34十二47没做“信息安全理论与技术"习题及答案教材:《信息安全概论》段云所，魏仕民，唐礼勇，陈钟，高等教育出版社第一章概述（习题一,p11)1.信息安全的目标是什么?答:信息安全的目标是保护信息的机密性、完整性、抗否认性和可用性；也有观点认为是机密性、完整性和可用性，即CIA(Confidentiality，Integrity，Availability)。
机密性（Confidentiality)是指保证信息不被非授权访问;即使非授权用户得到信息也无法知晓信息内容，因而不能使用完整性(Integrity）是指维护信息的一致性，即信息在生成、传输、存储和使用过程中不应发生人为或非人为的非授权簒改。
抗否认性（Non—repudiation)是指能保障用户无法在事后否认曾经对信息进行的生成、签发、接收等行为,是针对通信各方信息真实同一性的安全要求.可用性(Availability）是指保障信息资源随时可提供服务的特性.即授权用户根据需要可以随时访问所需信息。
2.简述信息安全的学科体系。
解：信息安全是一门交叉学科,涉及多方面的理论和应用知识.除了数学、通信、计算机等自然科学外，还涉及法律、心理学等社会科学.信息安全研究大致可以分为基础理论研究、应用技术研究、安全管理研究等。
信息安全研究包括密码研究、安全理论研究；应用技术研究包括安全实现技术、安全平台技术研究；安全管理研究包括安全标准、安全策略、安全测评等.3. 信息安全的理论、技术和应用是什么关系？如何体现？答：信息安全理论为信息安全技术和应用提供理论依据。
信息安全技术是信息安全理论的体现,并为信息安全应用提供技术依据。
信息安全应用是信息安全理论和技术的具体实践.它们之间的关系通过安全平台和安全管理来体现。
安全理论的研究成果为建设安全平台提供理论依据.安全技术的研究成果直接为平台安全防护和检测提供技术依据.平台安全不仅涉及物理安全、网络安全、系统安全、数据安全和边界安全，还包括用户行为的安全,安全管理包括安全标准、安全策略、安全测评等。
美军现代化战场通信
Experiment Wargame Analyze Evaluate Integrate
versatile mix …tailorable …networked …rotational cycle… sustained flow of ready forces for full spectrum opns …hedge against unexpected …sustain all-volunteer force Capabilities to Joint Force Commanders organizations of well-trained soldiers possessing right skill sets with superior equipment employing sound doctrine led by competent and confident leaders who understand their organizations’ potential and are empowered in combat by superior information supported by state-of-art facilities
– Fighting Vehicles, Aircraft, Tactical Wheeled Vehicles, Battle Command and Networks, and ISR.
Develop process to routinely make fleet sustainment decisions based on cost benefit analysis
Aviation: $6.0B
$31.7B
新指令下的美国国家安全局_潘志高
新指令下的美国国家安全局潘志高*根据今年1月美国国防部长颁布的第5100.20号指令,¹美国国家安全局在保持其政府的密码主导机构地位的前提下,将重点开拓信息保障(I nfor-m ati o n A ssurance)职能,负责为美国政府的秘密行动和信息安全服务,并为美国武装力量的行动提供和平时期、紧急情况、危机时期和战时的信号情报与信息保障。
一、国家安全局的职能、组织和关系(一)职能。
国家安全局是美国政府密码研发与应用的主导机构,其任务包括信号情报和信息保障。
信息保障是指确保包括网络安全在内的通讯安全、信息安全,即确保信息能及时、不受影响地送达用户手中,同时保持所存储、传输信息的权威性、不被破坏。
国家安全局负责向国防部各部门和国家用户提供信号情报,以及信息保障指导与协助服务。
国家安全局局长作为信号情报的职能主管,负责计划、组织、指挥、管理该局及其他资源,为美国武装力量的行动提供和平时期、紧急情况、危机时期和战时的信号情报与信息保障,为美国政府的秘密行动和信息安全服务。
此外,国家安全局还负责/关键信息通讯系统0的建立、运作和维护。
1、信号情报。
搜集、处理、分析、生产和分发信号情报,为美国有关部门提供信号情报支持;为军事行动提供信号情报;为信号情报的定密、销密制定规则和标准;实施信号情报行动控制,为政府各部门的信号情报活动制定政策和程序,并提供指导和协助服务;进行信号情报研究、开发和系统设计、测试、评估;与负责情报的国防部副部长共同管理/国防特别导弹和宇航中心0的活动,并提供必要的信号情报支持。
2、信息保障。
(1)作为美国/国家安全通讯和信息系统安全0的主管,为/国家安全系统0评估和批准所有的通讯安全、信息安全及其他信息保障标准、技术、系统和设备,评估/国家安全系统0安全态势,通告发现的针对这些系统的威胁及系统弱点。
美国/国家安全系统0是指由于国防和外交利益需要保密,因而需要全天候保护的信息系统。
systemc的TLM_2_0_简介
3
TLM-2.0
Copyright © 2007-2008 by Open SystemC Initiative. All rights reserved.
OSCI TLM-2.0
INTRODUCTION
Transaction Level Modeling 101 OSCI TLM-1 and TLM-2 Coding Styles Structure of the TLM-2.0 Kit
Transaction-level memory-mapped bus modeling Register accurate, functionally complete Fast enough to boot software O/S in seconds Loosely-timed and approximately-timed modeling Interoperable API for memory-mapped bus modeling Generic payload and extension mechanism Avoid adapters where possible
Dec 2006
Nov 2007 • TLM 2.0-draft-2 • nb_transport • New payload & extensions
Jun 2008
• TLM-2.0-draft -1 • Generic payload
• TLM-2.0 • Unified interfaces and sockets
13
TLM-2.0
Copyright © 2007-2008 by Open SystemC Initiative. All rights reserved.
网络管理概论 填空题
第一章网络管理概论[填空选择题]一、网络管理的基本概论P1-21、网络管理：指对网络的运行状态进行监测和控制,并能提供有效、可靠、安全、经济的服务。
2（International Organization for Standards）P13、国际标准化组织ISO推出的OSI系统管理标准是P14、网络管理系统（工具）P11）通用网络管理系统开发软件：NetView（由IBM公司研制开发）、OpenView（由HP公司研制开发）2）与硬件结合的网管工具：Works2000（Cisco）、Cabletron Spectrum这些系统有的是主机厂家开发的通用网络管理系统开发软件，有的则是网络产品制造商推出5、在TCP/IP网络中有一个简单的管理工具，用它来发送探测报文，可以确定通信目标的P16、OSI标准采用面向对象的模型定义管理对象。
二、网络管理系统的体系结构P2-61、在网络管理系统的层次结构中（见图1-2），管理站中在网络管理的支持协议簇的下一层（或者说在网络管理站中最下层）P22、管理功能分为管理站（Manager）和代理(Agent)两部分；将管理功能划分为两部分是各种网络管理框架的一个共同特点，被划分出的两部分是Manager和Agent。
P23、与管理站对话。
P34、网络管理实体(NME)：每一个网络结点都包含的一组与管理有关的软件叫做网络管理实体(NME)。
P35、网络中至少一个结点担当管理站的角色，在网络可以用作管理站的结点：主机或路由器。
P36、网络管理应用(NMA)：网络管理站中包含的一组用于网络管理的软件叫做网络管理应用（NMA）。
P37、代理模块：网络结点钟的NME模块叫做代理模块。
P38、网络中任何被管理的设备（主机、网桥、路由器或集线器等）都必须实现代理模块。
所有代理在管理站监视和控制下协同工作，实现集成的网络管理。
P39、对于大型网络，网络管理的趋势是分布式。
P310、委托代理：有些设备不支持当前网络管理标准或根本不能运行附加软件（称这些设备为非标准设备），通常处理方法用一个称为委托代理的设备（Proxy）来管理一个或多个非标准设备。
RS-485总线接口的保护
Application ReportSLLA292–May2009 Protecting RS-485Interfaces Against Lethal ElectricalTransients Thomas Kugelstadt ICP-Industrial InterfaceABSTRACTIndustrial networks must operate reliably in harsh environments.Electrical over-stresstransients caused by electrostatic discharge,switching of inductive loads,or lightningstrikes,will corrupt data transmission and damage bus transceivers unless effectivemeasures are taken to diminish transient impact.This article gives an overview of the three most commonly applied transient immunitytests,and provides recommendations on how to protect network nodes against realworld transients.Contents1Transient Immunity Tests (2)1.1Electrostatic Discharge(ESD)Immunity (2)1.2Electrical Fast Transients(EFT)Immunity (2)1.3Surge Immunity (3)2Test Levels and Priority (4)3Pass-Criteria (5)4Protection Circuitry (5)5Guidelines for Circuit and PCB Design (7)6Conclusion (8)7References (8)List of Figures1Current Wave Form of ESD Pulse and Timing Sequence of Pulses (2)2Voltage Wave Form of an EFT(Burst)Pulse and Timing Sequence of an EntireTest Cycle (3)3Voltage and Current Wave Form of a Surge Pulse and Timing Sequence of a TestCycle (3)4Industrial2-Pair and1.5-Pair RS-485Cables With Shield and Drain Wire (5)5Protection Circuitry for Transient Immunity (6)6TVS Characteristics and Clamp Voltage Impact (6)7TVS Diodes in Various Topologies and Power Ratings (7)8Routing Options for Different Topologies (8)List of Tables1EMC Test Requirements (4)1Transient Immunity Tests1.1Electrostatic Discharge (ESD)ImmunityTime -nsI O U T /I O U T -p e ak1101.2Electrical Fast Transients (EFT)ImmunityTransient Immunity Tests The following three transient immunity tests are part of the IEC61000-4family of electromagnetic compatibility tests,specified by the International Electrotechnical Commission (IEC).The Electrostatic Discharge (ESD)Immunity test,IEC61000-4-2,simulates the electrostatic discharge of an operator directly onto an adjacent electronic component.Electrostatic charge usually develops in low relative humidity,and on low-conductivity carpets,or vinyl garments.To simulate a discharge event,an ESD generator applies ESD pulses to the equipment-under-test (EUT),which can happen via direct contact with the EUT (contact discharge),or via an air-gap (air-discharge).Characteristic for this test are the short rise time and the short pulse duration of less than 100ns,indicating a low-energy,static pulse.This test requires a minimum of 10single discharge of positive and negative polarity with a recommended time interval between discharges of 1second.Figure 1.Current Wave Form of ESD Pulse and Timing Sequence of PulsesThe test procedures of many electronic equipment manufacturers ascribe ESD tests the lowest priority of all transient immunity tests as their potential occurrence is limited to the handling,installation andmaintenance work of input modules,during which operators are advised to wear ESD protective clothes as well as to intentionally discharge themselves prior to any direct contact with the module.The test for Electrical Fast Transients (EFT)or Burst Immunity,IEC61000-4-4,represents the most important test as it simulates the everyday switching transients caused by the interruption of inductive loads,relay contact bounce,etc.This test is performed on power-,signal-,and Earth wires.A burst isdefined as the sequence of pulses of limited duration.In this case,a burst generator produces a sequence of test pulses with a decay time,(down to 50%of the peak value),of less than 100ns.The typical duration of a burst is 15ms at a repetition rate of 5kHz.The burst period,the time from one burst start to the next,is 300ms.Significant for the test pulse are its short rise time,the high repetition rate,and its low energy content.This test requires the application of six burst frames of 10seconds duration with 10seconds pause intervals between frames.2Protecting RS-485Interfaces Against Lethal Electrical TransientsSLLA292–May 20091.00.90.50.1Time -ns0.80.70.60.40.30.20V O U T /V O U T -p e a k1.3Surge Immunity1.00.90.50.1Time -µs0.80.70.60.40.30.20V O U T /V O U T -p e a kTransient Immunity TestsFigure 2.Voltage Wave Form of an EFT (Burst)Pulse and Timing Sequence of an Entire Test Cycle While the fast rise time and the low energy content of an EFT are similar to the ones of an ESD pulse,the number of pulses per test cycle is not.Assuming a 1µs interval between pulse-front to pulse-front,an EFT burst of 15ms duration contains at least 15000pulses.Multiplied by the number of bursts within a 10s window,which is 10s/300ms =33.3bursts,yields 500,000pulses per 10s window.Thus the application of six 10s windows with a 10s pause interval results in a cool 3million pulses within 50seconds.This sheer endless pounding of transients upon the EUT appears to become an insurmountable task for the protection circuit to survive.However,since the EFT testing does not involve the direct contact of conductors but rather the indirect application via a capacitive clamp,the choice of a proper,industrial RS-485cable with internal shielding can produce a remedy to the DUT by attenuating the coupling of EFT energy into the conductors.While the Surge Immunity Test,IEC61000-4-5,is the most severe transient immunity test in points of current and duration,its application is often limited to long signal and power lines (L >30m).This test simulates switching transients caused by lightning strikes,(direct strike or induced voltages and currents due to an indirect strike),or the switching of power systems including load changes and short circuits.The surge generator’s output waveforms are specified for open-and short-circuit conditions.The ratio of the open-circuit peak-voltage to the peak short-circuit current is the generator output impedance.Characteristic for this test are the high current,due to low generator impedance,and the long pulseduration,(approximately 1000-times longer than for ESD and Burst tests),indicating a high-energy pulse.Figure 3.Voltage and Current Wave Form of a Surge Pulse and Timing Sequence of a Test Cycle2Test Levels and PriorityTest Levels and Priority This test requires 5positive and 5negative surge pulses with a time interval between successive pulses of 1minute or less.A common procedure is to shorten the pause intervals down to 12seconds,thus reducing total test time below 2minutes.While this approach intensifies the surge impact,due to the protection circuits reduced recovery time between pulses,it contributes to a significant reduction in test cost.To protect electronic equipment adequately against electrical transients regional standard bodies have established a list of transient immunity test requirements which can vary in the level of test voltages applied.Table 1lists a typical set of requirements and their applied test levels for industrial applications.Table 1.EMC Test RequirementsImmunity Priority StandardPort Voltage Level Test Power lines ±4kV 41Burst IEC61000-4-4,(5/50ns via capacitive clamp)Signal lines ±2kV 4IEC61000-4-5,(1.2/50µs–8/20µs),42Ω–0.5µF Signal lines ±0.5kV 12Surge IEC61000-4-5,(1.2/50µs–8/20µs),2Ω–18µF Power lines ±1kV 2IEC61000-4-2,in air gap Power and signal lines ±15kV 43ESDIEC61000-4-2,in contactPower and signal lines±8kV41.Because the Burst test simulates the everyday switching transients,it has the highest priority of the three transient immunity tests.While low in energy content,the vast numbers of transients continuously bombard the protection circuitry without much time for recovery.2.The surge test,although of far less occurrence,ranks next due to its high energy content and lethal impact on electronic components.It is important to notice that lightning,can produce current surges in the range of tens of thousands of amps (10kA to 100kA).While primary protection devices located at a building’s boundary,try to diminish the initial surge as much as possible,the remaining currents between 1kA to 4kA can still traverse along power lines into the building.Their large magnetic fields can easily couple into adjacent data communication lines if proper shielding is not applied.3.The test of least importance is the one for ESD immunity.It is proven that the main cause of ESD failures in the field is due to human involvement during the rare events of network installation andmaintenance.Furthermore,the enforcement of wearing ESD protective clothing during these activities reduces the risk of electrostatic discharge to a minimum.Protecting RS-485Interfaces Against Lethal Electrical Transients4SLLA292–May 20093Pass-Criteria4Protection CircuitryAWGFoam High DensityAluminum FoilDrain WireBelden3107ABelden3106AAWGFoam High DensityAluminum FoilDrain Wire Pass-CriteriaThere are three pass-criteria defining of how well a device or equipment must perform during and after a transient test.•Criterion A allows no performance degradation during the application of noise transients,thus requiring normal operation during and after the test.With regards to the RS-485or CAN bus,this means that the bit-error-rate of the data transmission should stay consistently low.•Criterion B accepts some degradation in performance,such as unintentionally logic-state changes, which inevitably will lead to a BER increase.However,after the test,the system must beself-recoverable and return to normal operation.•Criterion C accepts the loss of function,such as a latch-up event,but without device damage.After test,a manual restart or toggling of the power supply is necessary to return the system to normaloperation.While the data sheets of many transceiver devices claim high ESD protection levels of up to30kV,they often fail to state the pass-criterion applied.Therefore,during ESD testing expect the BER to increase as many devices are designed with criterion B in mind.Also relying solely on a transceiver’s integrated ESD structure when designing a data link for real world application,may fail.A robust data link requires external protection circuitry to absorb the much higher impact of burst and surge transients.Reliable protection against electromagnetic interference begins with the right choice of transmission cable.Choosing industrial RS-485cable over cheap unshielded twisted pair(CAT5)or flat-band cable has two major advantages:1.The cable’s nominal characteristic impedance of Z0=120Ωmatches the switching characteristics ofRS-485transceivers,thus minimizing signal distortion caused by reflections due to impedancemismatch,2.The braided shield provides substantial attenuation to noise currents induced by burst and surgetransients,thus reducing the impact on subsequent transient protection devices.Figure4.Industrial2-Pair and1.5-Pair RS-485Cables With Shield and Drain WireAlthough industrial RS-485cable is available with up to4signal-pairs,Figure4shows only a1.5-pair and a2-pair sample for half-duplex data links.In both cases,one signal to the A and B terminal of an RS-485board connector,and the ground conductor(s)plus the drain wire connect to the groundterminal of the ing an entire signal pair for the ground connection,as in the case of theBeldon3107A cable,assures a lower ground inductance path for transient currents returning from theboard than the single ground conductor of the Belden3106A cable.Figure5shows the circuit schematic of a basic RS-485node.A screw terminal,serving as the RS-485 connects the transmission cable to the transceiver(XCVR).Three transient voltage suppressor diodes(TVS)are used to eliminate common-mode transients between A and ground and B and ground, and differential transients between A and B.TransientProtection Circuitry Figure 5.Protection Circuitry for Transient ImmunityModern transient voltage suppressors are the preferred protection components for high-speed data transmission due to their low capacitance,which allows them to be designed-in into every node of a multi-node network without requiring a reduction in data rate.With response times of a few picoseconds and power ratings of up to several kilowatts TVS diodes present the most effective protection against ESD,burst,and surge transients.Figure 6shows the V-I characteristics of a TVS.Up to the stand-off voltage,V WM ,the transient suppressor is high-impedance and only a few micro-amps of leakage current pass through the device.Therefore,when selecting a TVS make sure its stand-off voltage is above or equal to the maximum bus voltage potential during normal operation,V WM ≥V A ,V B .At the break-down voltage,V BR ,the TVS begins clamping,that is the device becomes low-impedance and starts conducting high current.Due to its dynamic impedance,current flowing through the TVS creates a voltage drop,known as the clamping voltage,V C .This voltage rises with increasing current.Unfortunately,the clamping voltage often exceeds the maximum voltage ratings of a transceiver’s bus terminals.Figure S Characteristics and Clamp Voltage ImpactFor example,to comply with the RS-485specified common-mode voltage range of –7V to 12V,TVSstand-off voltages should be V WM ≥12V.Depending on the power rating of the TVS chosen,the maximum clamp voltages can range from 25V up to 35V,which is significantly higher than the maximum bus voltage of 14V of a standard transceiver.In this case,the internal protection circuit of the transceiver must absorb the remaining clamp energy to protect the device from damage.6Protecting RS-485Interfaces Against Lethal Electrical TransientsSLLA292–May 20095Guidelines for Circuit and PCB DesignPSM712(600W)PSD12C (400W)SMDB12C (800W)SML12C-2(3600W) Guidelines for Circuit and PCB DesignFor ESD and burst transients,the clamp energy is low due to the short pulse duration,and does not pose a problem to the internal ESD cells.Clamp energy from surge transients;however,can present a serious challenge due to the much longer pulse duration.For transceivers specified with low ESD immunity,it may be necessary to reduce the remaining current flowing into the transceiver through series resistors.Common resistor values range from 10Ωto 20Ω.Note these resistors must be surge-rated to provide high pulse robustness.In addition to the suppressor action on the transceiver bus side,further protection against signaldegradation is required on the transceiver single-ended side.This is accomplished with R-C low-pass filters which filter transient remnants in the receive path,and stop high frequency noise from entering the transmit path.Do not treat transient protection as an add-on feature,instead plan for it at the beginning of the design.•To accomplish an EMI robust board design,use a four-layer PCB with layer stacking in the following order (top-to-bottom):Bus signal layer,ground plane,power plane and control signal layer.–Routing the differential signal traces on the top layer avoids the need for vias (and the introduction of their inductances)and allows for clean interconnects between the connector and the transceiver.–Placing a solid ground plane next to the bus signal layer provides an excellent low-inductance path for return currents and establishes controlled impedance for transmission line interconnects.–Placing the power plane next to the ground plane creates additional high-frequency bypass capacitance of approximately 100pF/in 2.–Routing the control signals on the bottom layer provides greater routing flexibility as these signal links have margin to tolerate discontinuities such as vias.•When choosing a transient suppressor diode assure that the stand-off voltage is above the expected common-mode voltage range,which can be smaller or larger than the –7V to 12V specified by EIA-485.•In addition to select a TVS with sufficient power rating,look for a device topology that allows smooth routing of the signal traces between the connector and the transceiver.Figure 7presents some TVS diodes with 12V stand-off voltage,but different power ratings and Figure 8provides routing suggestions for minimum inductance paths,based on the TVS component layout.Figure S Diodes in Various Topologies and Power RatingsA BA BA B6Conclusion7ReferencesConclusionFigure 8.Routing Options for Different Topologies•Do not let the transients pass across the circuit board.Eliminate them right at the board entrance by placing the transient voltage suppressors as close to the connector as possible.•Ground TVS with multiple ground vias to make inductance between TVS and ground plane lower than the signal trace inductance between TVS and transceiver.Note that transients contain high-frequency components which follow the path of least inductance.•Introducing some distance between the TVS and the transceiver is recommended as it increases the signal trace inductance.This approach not only makes the signal trace the less preferred path for transients,it also slows down the edges of any transient remnants.•For transceivers with low ESD rating insert surge-rated 10Ωto 20ΩMELF resistors in series to the transceiver bus terminals to reduce the remaining TVS clamp energy.•Implement EMI filtering on the single-ended side of the transceiver through simple R-C low-pass filters.•Apply 100nF by-pass capacitors as close as possible to every IC.Ground each capacitor with at least two vias to the ground plane to reduce the total via inductance.Note,because of V =L ×di/dt,even small inductances can cause significant high voltages due to fast transient rise times.Electrical over-stress transients,such as ESD,burst,and surge pulses vary in rise time,duration and energy content.Protecting RS-485network nodes against these transients requires more than just a high ESD rating of the transceiver.Industrial RS-485cabling in combination with external transient voltage suppressors placed closely to the bus connector provide the most efficient protection against all three types of transients.•Further information on RS-485transceivers is available at .•.•For information on industrial RS-485cable visit .8Protecting RS-485Interfaces Against Lethal Electrical TransientsSLLA292–May 2009。
N6705C 直流电源分析仪
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认证
是德科技保证本产品出厂时符合其发布的技术指标。是德科技进一步保证其校准测量遵循美 国国家标准和技术研究院的规定，并符合该研究院及其他国际标准组织成员制定的校准设备 规范。
7
Keysight N6705C 用 户 指 南
法律和安全信息
美国政府的权利
本 软 件 为 符 合 联 邦 政 府 采 购 法 规 ("FAR") 2.101 规 定 的 “商 用 计 算 机 软 件 ”。 按 照 FAR 12.212 和 27.405-3 以 及 国 防 部 FAR 补 充 条 款 ("DFARS") 227.7202， 美 国 政 府 根 据 向 公 众 提 供 商 用 计 算 机 软 件 的 一 般 条 款 采 购 本 软 件 。 相 应 地 ， 是 德 科 技 依 据 其 最 终 用 户 许 可 协 议 (EULA) 中 所 述 的 标 准 商 业 使 用 许 可 向 美 国政府客户提供本软件，您可以从以下网址获取该许可协议的副本： /find/sweula。 EULA 中 所 述 的 许 可 表 示 美 国 政 府 使 用 、 修 改 、 分 发 或 披 露 本 软 件 所 具 有 的 专 属 权 利 。 除 了 其 他 事 项 之 外 ， EULA 及 其 中 规 定 的 许 可 不 要 求 或 不 允 许 是 德 科 技 ： (1) 提 供 通 常 不 会 向 公 众 提 供 的 与 商 用 计 算 机 软 件 或 商 用 计 算 机 软 件 文 档 相 关 的 技 术 信 息 ； 或 者 (2) 让 与或以其他方式提供的政府权利超过通常向公众提供的与使用、修改、复制、发布、执行、显示 或 披 露 商 用 计 算 机 软 件 或 商 用 计 算 机 软 件 文 档 有 关 的 权 利 。 EULA 中 未 涉 及 的 其 他 政 府 要 求 不 适 用 ， 除 非 按 照 FAR 和 DFARS 的 规 定 明 确 要 求 所 有 商 用 计 算 机 软 件 提 供 商 提 供 这 些 条 款 、 权 利 或 许 可 证 ， 并 且 EULA 中 的 其 他 地 方 有 专 门 的 书 面 说 明 。 是 德 科 技 对 更 新 、 修 订 或 以 任 何 其 他 方 式 修 改 本 软 件 不 承 担 任 何 责 任 。 对 于 FAR 2.101 定 义 的 任 何 技 术 数 据 ， 根 据 FAR 第 12.211 条 和 第 27.404.2 条 以 及 DFARS 第 227.7102 条 的 规 定 ， 美 国 政 府 所 获 得 的 权 利 不 会 超 出 FAR 第 27.401 条 或 DFAR 第 227.7103-5 (c) 条 所 定 义 的 适 用 于 任 何 技 术 数 据 的 “有 限 权 利 ”。
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InformationGatheringSupportInterfacebytheOverviewPresentationofWebSearchResults
TakumiKobayashiKazuoMisueBuntarouShizukiJiroTanakaGraduateSchoolofSystemsandInformationEngineeringUniversityofTsukuba,Tennoudai1-1-1,Tsukuba,Ibaraki,Japan305-8571Email:{takumi,misue,shizuki,jiro}@iplab.cs.tsukuba.ac.jp
AbstractTheInternetconsistsofseveralbilliondocuments.ChoosinginformationfromsuchagreatnumberofWebpagesisnoteasy.Wedonotthinkthattheinter-facesoftraditionalsearchenginesthatdividesearchresultsintodozensofpagesregardlessofgenreanddisplaytheresultsasatext-basedlistarenecessarilyuseful.WeproposeaninterfacethathelpstheusertointuitivelyunderstandtheentireWebsearchresultandtogatherinformation.OursystemanalyzesandclassifiesWebsearchresultsandpresentstheclassifi-cationresultstotheuserononescreen.Keywords:Websearch,Informationgathering,Clus-tering,Visualization,Interface,Hyperbolictree1IntroductionTheInternetisusedbypeopleallovertheworld.Asitspreads,thevolumeofinformationavailableandthenumberofWebpagesisincreasingrapidly.Accord-ingtoInternetSystemsConsortium,Inc.,thenumberofhostsconnectedtotheInternetismorethan350million(InternetSystemsConsortium,Inc.2005).Havingsuchahugeamountofinformation,weneedtouseasearchenginetoretrievetheinforma-tionthatisrelevanttous.WhenweconductaWebsearch,wecanusedifferentkindsofretrievalstoob-taindifferentkindsofinformation.WemayconductaWebsearchthatfindsoneormoreWebpagesre-latedtoaspecifictopic.OneexampleisaretrievaltoobtaininformationonvarioustopicsaboutJapan.AndreiBrodercallssuchaWebsearchan”informa-tionalWebsearch”(Broder2002).Whenausercon-ductssuchasearch,(s)hemustviewagreatnumberofWebsearchresultsfromvariousviewpointsandchoosefromthem.AsearchforinformationaboutJapanisabstractandincludesinformationonpoli-tics,traffic,touristspots,andsoon.Therefore,theusershouldnotgatherinformationfromaspecificWebpagealonebutshouldgatherinformationfromavarietyofpages.AconventionalkeywordsearchinterfacepresentsvariousproblemswhenweconductaninformationalWebsearch.TheseproblemsmaketheWebsearchdifficult.GatheringinformationefficientlyisdifficultwhenusingaconventionalWebsearchinterfacethatpresentssearchresultsasatext-basedlistbecausesuchaone-dimensionallistconsistsofvariousgenresofWebpages.Inaddition,thedisplaymethod,whichCopyrightc2006,AustralianComputerSociety,Inc.Thispa-perappearedatAsia-PacificSymposiumonInformationVisu-alization(APVIS2006),Tokyo,Japan,February2006.Confer-encesinResearchandPracticeinInformationTechnology,Vol.60.K.Misue,K.SugiyamaandJ.Tanaka,Ed.Reproductionforacademic,not-forprofitpurposespermittedprovidedthistextisincluded.dividessearchresultsintodozensofpages,doesnotallowtheusertointuitivelyunderstandthefeaturesoftheentiresearchresult.Therefore,theusermightoverlookprofitableinformation.WeproposeasystemthatclassifiesWebsearchresultsaccordingtothecontentofthepages.Oursystempresentstheclassificationresultswithsomelabelsononescreen.
2OverviewPresentationSystemWeproposeaninterfacethataidsinformationgather-ingwiththefollowingfeaturestosolvetheproblemsofconventionalWebsearchinterfaces.
1.TheinterfacearrangessimilarWebpagesinneighborhoodsinatwo-dimensionalspace.
2.Theinterfacepresentsclassificationresultstotheuserononescreen.
OursystemcategorizesWebsearchresultsintoclus-tersaccordingtothecontentoftheWebpagestoarrangesimilarWebpagesinneighborhoods.Theconceptoffeature1isshowninFigure1.TheusercangatherinformationmoreefficientlybecausethesystemdoesnotscattervariousgenresofWebpagesbutarrangestheminneighborhoods.Webpagesthattheuserdoesnotwantinthesearchresultsarear-rangedinneighborhoodsaccordingtotheirgenres.Thus,theusercanavoidlookingthroughdistractingscatteredWebpageswhich(s)hedoesnotwant.Oursystempresentssearchresultsinatwo-dimensionalspace.Thisdisplaymethodofferstheuseraretrievalthatismoreflexiblethanaone-dimensionalpresentationinterfacebecausetheuserdoesnothavetosequentiallycheckaone-dimensionallist.
Figure1:Feature1ConventionalWebsearchenginesvisualizesearchresultsastext-basedlists.However,oneproblemwiththesesearchenginesisthattheyreturntoomuchin-formation.Theusercannotintuitivelyunderstandtheentiresearchresult.Inaddition,theresultlistisdividedintosmallportions,butonly5to10resultscanfeasiblybeviewedonthescreenatanyonetimewithoutscrolling,whichforcestheusertoclickon