... iPhone AppThe web browser built into the iPhone is one of the most advanced browsers on the market. Features such as CSS transi-tions and animation were part of the iPhone Mobile Safari web browser ... although jQTouch is built using HTML5 standards ontopof the jQuery framework, it has not been optimized to run on all devices. For instance, response time on Windows Phone 7 has not been ... 3.16.Location Aware SolutionsThe final plug-in leverages the geolocation features built into the phone to present the longitude and latitude of your current position.This one will take a little...
... safely deploy Linux in a mission critical environment.”(otn.oracle.com/tech /linux) HP: “HP is hosting a number ofopensource software projects thatrun on various HP systems.” (opensource.hp.com)Apple: ... difficult to estimate the size ofopensource software in-dustry”. Pure opensource companies are tiny and many of them are pri-vately held. However, the popularity ofopensource is significant andpractically ... for both systems and applications FROM PROPRIETARY TO OPEN ã 18 Operating system: BSD*, Linux* , Solaris,WindowsServer software:Apache*, Microsoft IIS,SunONE, Zope*Database: MicrosoftSQL,...
... general.In this chapter, we report on the results of a continuing study of theeffort and motivations of individuals to contributing to the creation of Free /Open Source software. We used a Web-based ... engineer-ing, of organizations and organizing, of the software industry, and of software as a component of contemporary society.JF, BF, SAH, and KRL phenomenon. Starting with the collapse of the Berlin ... Software Development 794 Standing in Front of the OpenSource Steamroller 81Robert L. Glass5 Has OpenSource Software a Future? 93Brian Fitzgerald6 OpenSource Software Development: Future or Fad?...
... context switching and scheduling.One of the goals of Mach is to provide an extensible kernel basis upon which operatingsystem environments suchas UNIX can be built. Emulation of UNIX-like system ... exception of the hardware validation, all of these steps are implemented in a machine-independentfashion. 178.2. Copy -On- Reference Task MigrationOne of the thorniest problems of task migration ... experimental addition. A production version of Mach is in use on over 200 workstations and large timesharing systems within the CMU Department ofComputer Science. It is alsobeing used on dozens of machines...
... evaluationand description of distributed systems characterized by sequen-tiality, concurrency, synchronization, among others. Specifi-cally, the GSPN [8] is one of the several extension of standardPNs ... transitions were supposedto have constant probability of firing. However, there is astrong correlation between the operating conditions of powersystems and the probability of harmful events. To consider ... producedifferent consequences depending on the power system state.In conclusion, the reliability of protection schemes, understoodas the union of dependability and security, and its dependency on the system...
... function of subsystem ; is the number of components in subsystem i; iniM is the number of possible states of subsystem i. is the performance of subsystem i; is the corresponding ... function of the system; is the number of subsystems in the system; NsysM is the number of possible states of the system; sG is the performance of the system; sq is the corresponding ... multi-state system theory. II. PROBLEM FORMATION The power system is composed of eight identical batteries. A branch consists of two batteries connected in series, and the system consists of...
... 267.66 cm-1 of the deformation mode and 802.5 cm-1 of covalent bonds W – O, there is only one clear modification, comparing to Raman spectra of film on thinner ITO layers. The only difference ... crystalline phase of WO3. The Raman peak at 256.6 cm-1 indicates the deformation vibration of O – W – O bond and 600 – 900 cm-1 region relates to stretching vibrations of W – O bonds [24]. The ... Gaussian function. This information gives us exact evaluation of the existence of different phases in our films. 3. Results and discussion 3.1. The effect of the thickness of ITO layer on XRD spectrum...
... collapse.Pulmonary function testsSpecifics of pulmonary function testing in an olderpopulationThe application of conventional quality controlstandards to objective assessment of pulmonaryfunction ... index de-scribes the relationship between force of contraction(Pdi/Pdimax) and duration of contraction (ratio of inspiratory time to total respiratory cycle duration[TI/TTOT]) and is related ... Quality control of spirometry in the elderly. The S.A.R.A. study.SAlute Respiration nell’Anziano = Respiratoryaging of the respiratory system 481 Aging of the Respiratory System: Impact on PulmonaryFunction...
... conformational states. Open conformation of WtDSD is shown indark grey while the closed conformation of SeMetDSD is shown in light grey. The smalldomains are related by a residual rotation of 15°. ... for the cofactor under crystallization conditions. Interestingly,unexpected conformational differences were observed between the two struc-tures. The WtDSD was in an open conformation while ... reac-tions catalysed include the transfer of amino group,decarboxylation, inter-conversion of l- and d-aminoacids and removal or replacement of chemical groupsat a, b or c positions [1]. Functionally,...
... Figure5:AcquiringtheVirtualRelationsPKCONTandHEMICwindowforquestionsandanswers.WhentheDBEusesthemousetoselectone of theitemsfromthethreemenus,aset of questionsappearsinthequestion-answeringareaatthebottom of thedisplay,towhichhecanthenrespond.One of thegeneralprinciples of acquisitionisevidentfromthisdisplay,namely,thattheacquisitioniscenteredupontherelationsandfieldsinthedatabase,becausethisistheinformationmostfamiliartotheDBE.Theanswerstoeachquestioncanaffectthelexicon,theconceptualschema,andthedatabaseschema.TheDBEneednotbeaware of exactlywhyTEAMposesthequestionsitdoes—allhehastodoisanswerthemcorrectly.Eventheentriesdisplayedinthewordmenuowetheirpresencetoquestionsaboutthedatabase.TheDBEvolunteersentriestothismenuonlyinthecase of verbacquisition,tosupplyanadjectivecorrespondingtosomenounalreadyinTEAM’slexicon,ortoenterasynonymforsomelexicon-residentword.TheDBEisassumednottohaveanyknowledge of formallinguisticsor of natural-languageprocessingmethods.Heisassumed,however,toknowsomegeneralfactsaboutEnglish—forexample,whatpropernouns,verbs,plurals,andtenseare,butnothingmoredetailedthanthat.Ifmoresophisticatedlinguisticinformationisrequired,asinthecase of verbacquisition,TEAMproceedsbyaskingquestionsaboutsamplesentences,allowingtheDBEtorely on hisintuitionasanativespeaker,andextractingtheinformationitneedsfromhisresponses.Virtualrelationsarespecifiediconically.Theleftside of Figure5showstheacquisition of avirtualrelationthatidentifiesthecontinent(PKCONT-CONTINENT,derivedfromWORLDC-CONTINENT) of apeak(PKCONT-NAME,fromPEAK-NAME)byperformingadatabasejoin on thePEAK-COUNTRYandWORLDC-CONTINENTfields.Similarly,therightside of Figure5showstheacquisition of thevirtualrelationthatencodesthehemisphere(HEMIC-HEMI) of acountry(HEMIC.NAME)byjoining on theWORLDC-CONTINENTandCONT-NAMEfields.Ifhewishes,theDBEcanchangepreviousanswers.Incrementalupdatesarepossiblebecausemost of themethodsforupdatingthevariousTEAMstructures(lexicon,schemata)weredevisedtoundotheeffects of previousanswersbeforetheeffects of newanswerscouldbeasserted.HelpinformationisalwaysavailabletoassisttheDBEwhenheisunsurehowtoansweraquestion.Selectingthequestiontextwiththemouseproducesamoreelaboratedescription of theinformationTEAMistryingtoelicit,usuallyaccompaniedbypertinentexamples.Finally,theacquisitioncomponentkeepstrack of whatinformationremainstobesuppliedbeforeTEAMhastheminimumitneedstohandlequeries.TheDBEdoesnothavetodeterminehimselfhowmuchinformationissufficient;allhehastodoistoperceivethatnoacquisitionwindowindicatesremainingunansweredquestions. Of course,theDBEcanalwaysprovideinformationbeyondtheminimum—forexample,bysupplyingadditionalverbs,derivedadjectives,orsynonyms.—20— ... schema;7,hence,thechoice of logicalformindirectlyaffectsthedesign of thosecomponents of the system anddetermines,inpart,theinformationtheDBEmustsupply.ThelogicalformemployedbyTEAMisfirst-orderlogicextendedbycertainintensionalandhigher-orderoperatorsandaugmentedwithspecialquantifiersfordefinitedeterminersandinterrogativedeterminers.Muchresearchhasbeendonetodeviseappropriatelogicalformsformanykinds of sentencesMoor8l],butthatinvestigationliesbeyondthescope of thisarticle.2.3WhatInformationIsAcquired2.3.1TheLexiconThelexiconisarepository of theinformationabouteachwordthatisnecessaryformorphological,syntactic,andsemanticanalysis.Therearetwoclasses of lexicalitems:closedand open. Closedclasses(e.g.,pronouns,conjunctions,anddeterminers)containonlyafinite,usuallysmallnumber of lexicalitems.Typically,thesewordshavecomplexandspecializedgrammaticalfunctions,alongwithatleastsome]fixedmeaningsthatareindependent of thedomain.Theyarelikelytooccurwithhighfrequencyinqueriestoalmostanydatabase. Open classes(e.g.,nouns,verbs,adjectives)aremuchlargerandthemeanings of theirmemberstendtovary,depending on theparticulardatabaseanddomain.Therefore,mostclosed-classwordsare built intotheinitialTEAMlexicon,while open- classwordsareacquiredforeachdomainseparately.However,thereareanumber of open- classwords,suchasthosecorrespondingtoconceptsintheinitialconceptualschema(seeSection2.3.2)andwordsforcommonunits of measure(e.g.,“meter”,“pound”),thataresobroadlyapplicabletosomanydatabasedomainsthattheyareincludedintheinitiallexiconaswell.Lexicalentriesincludethoseforthenames of filesubjects(i.e.,theentitiesaboutwhichsomerelationcontainsinformation—e.g.,peaksforPEAK,andcountriesforWORLDCinthesampledatabaseillustratedinFigure1.3),fieldnames,andfieldvalues.Inaddition,theDBEcansupplyadjectivesandverbs,aswellassynonymsforwordsalreadyacquired(seeSection2.4).Associatedwitheverylexicalentryissyntacticandsemanticinformationforeach of itssenses.Syntacticinformationconsists of itsprimarycategory(e.g.,noun,verb,oradjective),subcategory(e.g.,count,unit,ormassfornouns;objecttypesforverbs),andmorphology.Semanticinformationdepends on thesyntacticcategory.Theentryforeachnounincludesthesort(s)orindividual(s)intheconceptualschema(Section2.3.2)towhichthatnouncanrefer.Entriesforadjectivesandverbsincludetheconceptualpredicatetowhichtheyrefer,plusinformationabouthowthevarioussyntacticconstituents of asentencemapontoarguments of thepredicate.Scalaradjectives(e.g.,“high”)alsoincludeanindication of direction on thescale(plusorminus).2.3.2ConceptualSchemaTheconceptualschemacontainsinformationabouttheobjects,properties,andrelationsinthedomain of thedatabase.Itincludessets of individuals,predicates,constraints on thearguments of predicates,andtheinformationneededforcertainpragmaticprocessing.Theinformationalcontentissimilartothatcommonlyencodedinsemanticnetworks,buttheapparatususedismoreeclectic.Theconceptualschemaconsists of asorthierarchyanddescriptions of variousproperties of nonsortpredicates.Thesorthierarchyrelatescertainmonadicjpredicatesthatplayaprimaryroleincategorizingindividuals.Thesearecalledsortpredicates(representedhereinitalicsasinPERSON).TEAMwasdesignedwithaconsiderableamount of thisconceptualinformation built in.Figure3illustrates7Asnotedpreviously,thespecificformdependsalso on generalsyntactic,semantic,andpragmaticrulesforEnglishthatareencodedinthevariouscomponents of DIALOGIC.—16— ... continent of thecountry.Likewise,thehemisphereinwhichacountryislocatedcanbedeterminedfromthecontinent on whichthecountryislocatedandthehemisphere of thatcontinent.TEAMallowstheDBEtospecifyvirtualrelationsthatconveysuchadditionalinformation.2TheTEAM System ArchitectureThedesign of TEAMreflectsseveralconstraintsimposedbythedemandfortransportability;ourdiscussionwillemphasizethoseaspects of thedesign.Theneedtodecoupletherepresentation of whatausermeansbyaqueryfromtheprocedureforobtainingthatinformationfromthedatabaseobviouslyaffectedthechoice of system components.Inaddition,theneedtoseparatethedomain-dependentknowledgetobeacquiredforeachnewdatabasefromthedomain-independentparts of the system influencedthedesign of theparticulardatastructures(or“knowledgesources”)selectedforencodingtheinformationusedbythesecomponents.Figure2illustratesthemajorprocesses of TEAM,thevarioussources of knowledgetheyuse,andtheflow...
... usedtodeflectthereadingbeamveryfast.Asaresult,itismuchfastertoretrieveinformationfromtracksthatarelocatednearthecurrentlocation of thereadinghead.Wecallthisaspanaccesscapability.Thespanaccesscapability of opticaldiskshasimplicationsforschedulingalgorithmsanddatastructuresthatareappropriateforopticaldisks,aswellassignificantimpact on retrievalperformanceChristodoulakis87a].InChristodoulakis87]wealsoderiveexactanalyticcostestimatesaswellasapproximationsthatarecheapertoevaluate,fortheretrieval of recordsandlongerobjectssuchastext,images,voice,anddocuments(possiblycrossingblockboundaries)fromCAVopticaldisks.Theseestimatesmaybeusedbyqueryoptimizers of traditionalormultimediadatabases.RetrievalPerformance of CLVOpticalDisksConstantLinearVelocity(CLV)opticaldiskshavedifferentcharacteristicsthantheCAVopticaldisks.CLVopticaldisksvarytherotationalspeedsothattheunitlength of thetrackwhichisreadpassesunderthereadingmechanisminconstanttime,whichisindependent of thelocation of thetrack.Thishasimplications on therotationaldelaycostwhich,inCLVdisks,depends on thetracklocation.Thisalsoimpliesthat,inCLVdisks,thenumber of sectorspertrackvaries(outsidetrackshavemoresectors).Thelatter(variablecapacity of atrack)hasmanyfundamentalimplications on selection of datastructuresthataredesirableforCLVopticaldisksandtheparameters of theirimplementation,fortheselection of accesspathstobesupportedfordatabasesstored on CLVdisks,aswellasfortheretrievalperformanceandtheoptimalqueryprocessingstrategytobechosen.(TheseimplicationsarestudiedindetailinChristodoulakis87b],inwhichisshownthatthesedecisionsdepend on thelocation of dataplacement on thedisk.)Analyticcostestimatesfortheperformance of retrieval of recordsandobjectsfromCLVdisksarealsoderivedinChristodoulakis87b]).Theseestimatesmaybeusedbytraditionalormultimediaqueryoptimizers.Itisshownthattheoptimalqueryprocessingstrategydepends on thelocation of files on theCLVdisk.Thisimpliesthatqueryoptimizersmayhavetomaintaininformationaboutthelocation of files on thedisk.Estimation of SelectivitiesinTextInmultimediainformationsystemsmuch of thecontentspecificationwillbedonebyspecifyingapattern of textwords.Queriesbased on thecontent of imagesaredifficulttospecify,andimageaccessmethodsareveryexpensive.Voicecontentistransformedtotextcontentifagoodvoicerecognition18 ... Ajoinindexcapturesthesemanticlinksthatexistbetweentuples.Ifweviewthejoin of twotuplesasanarcconnectingthosetupleidentifiers,ajoinindexcanrepresentdirectedgraphsinaverycompactway.Therefore,itwillbeveryusefultooptimizegraphoperationsliketransitiveclosure.LetusconsideragainthePARTrelation:PART(pname,weight,price,spname)wherespnameisthename of asubpart(orcomponentpart).AssumingthatPIDandSPIDstandforPARTtupleidentifiers,thenwecanhavetwojoinindices(eachclustered on itsfirstattribute)Jl1(PID,SPID)J12(SPID,PID)J11associatesapart_idwithitssubpart_id’s,whileJ12associatesasubpart_idwithitsparentpart_id.Therefore,Jl1iswellsuitedfortraversalsinthepart—subpartdirection.J12allowsefficienttraversalsthatfollowthesubpart—partdirection.Assumingthatarecursivequeryismappedintoaconceptualquerytree of relationalalgebraoperatorsandtransitiveclosure,thequeryoptimizationalgorithmdiscussedinSection3stillapplies.However,theintroduction of transitiveclosureyieldsalargersolutionspace,sincetransitiveclosuremaybepermutedwithotherrelationaloperators(e.g.,selectandjoin).Thetransitiveclosureoperatorcanbeimplementedefficientlybyaloop of joins,unions,andpossiblydifference(forcyclicrelations).Superiorperformanceisconsistentlyattainedwhentransitiveclosureisappliedusingjoinindexratherthantheprimarycopy of therelationValduriez86a].Forinstance,letusconsidertherecursivequery on thePARTrelation“listthecomponentpartsandtheirpricesforpartA”.Figure3illustratesthecorrespondingquerytreeandapossibleprocessingtree,inwhichtransitiveclosure(notedIC)isappliedtothejoinindex.Theselection“pname=A”precedesthetransitiveclosuresothatonlythosepartsthatare(transitively)components of partAareproduced.InthePT,theresult of thetransitiveclosure on joinindexJIisaset of pairs(PID of A,PID of asubpart of A).Therefore,anadditionaljoinwithrelationPARTisnecessarytocompletethequery.Thus,themostcomplexpart of thequeryisdone on smalldatastructures(selectionindex,joinindex).Thevalue of performingthetransitiveclosureusingjoinindexistoavoidrepeatedaccesstorelationPART,whichispotentiallymuchlargerthanthejoinindex.pname_INDPARTJl1(PID,SPID)PARTapname=Aapname=A/PARTSPID1~1PID‘ITpname,price‘~pname,priceQueryTreePTwithJoinIndexFigure3:Processing of aRecursiveQuerywithJoinIndex5.ConclusionJoinindicesaredatastructuresespeciallydesignedtospeedupjoinoperations.Theincorporation of joinindicesinastoragemodelprovidesthequeryoptimizerwithalargersolutionspaceandhencemoreopportunitiesforoptimization.Wehaveillustratedtheuse of joinindicestooptimizenon—recur-15 ... condition of theform:“Namerestriction”.Therestrictionappliestobothcomponentswhosepath-namesareSender.NameandReceiver.Name.Theproblemistodecidehowsuchaconditionissatisfied.Therearefourpossibileinterpretations:(1)Namerestriction=Trueif(Sender.Namerestriction=True)A(~(Receiver.Namerestriction=True))(2)Namerestriction=Trueif(Sender.Namerestriction=True)A(V(R.eceiver.Namerestriction=True))(3)Namerestriction=Trueif(Sender.Namerestriction=True)V(V(Receiver.Namerestriction=True))(4)Namerestriction=Trueif(Sender.Namerestriction=True)V(3(Receiver.Namere8triction=True))Our system usesthethirdinterpretation,sinceitisthemostgeneral:theanswertoquery(3)containstheanswerstoqueries(1),(2),and(3).Thischoicereflectstheapproach of givingtotheuserthemostgeneralanswers,whenthereareambiguitiesinthequery.Then,theuser,whodidnotknowexactlythetypesdefinedinthedocumentbase,canrefinethetheoriginalqueryspecifyingexactlythemeaning of thequery.Thefourdifferentsemantics,inourquerylanguage,canbespecifiedexplicitlyas:(1)Sender.NamerestrictionandsomeReceiver.Namerestriction(2)Sender.NamerestrictionandeveryReceiver.Namerestriction(3)Sender.NamerestrictionoreveryReceiver.Namerestriction(4)Sender.NamerestrictionorsomeReceiver.NamerestrictionInadditiontotheprevioustypes of conditions,thelanguagemustallowconditions on theexistence of conceptualcomponentswithindocuments.Thisallowsexpressingqueries on theconceptualstructure of documents.Thereforewehavedefinedtheoperator“with”.Aconditioncontainingthe“with”operatorhastheform:“withcomponent”.Thisconditionexpressesthefactthatthecomponentwhosename(orpathname)isgivenmustbeaconceptualcomponent of thedocumentstoberetrieved.Toexpressconditionsthatrequirethataconceptualcomponenthavingnamenarne~iscontainedinaconceptualcomponenthavingnamename,,thepath-namename1*name,isused.The“with”operatorisconceptuallyveryimportantinourquerylanguage.Whiletheotheroperatorsallowthedefinition of conditions on data(ie.documentinstance),the“with”operatorallowsthedefinition of conditiou8 on meta-data(ie.documenttypes).Anexamplequerythatwillbeusedthroughoutthispaperis:finddocumentswhereDocument.Date>/1/1/1987/and(*Sender.Name=“Olivetti”or*ProductYresentationcontains“Olivetti”)and*Product.Descriptioncontains“PersonalComputerl”and(*Address.Country=“Italy”ortextcontains“Italy”)andwith*CompanyLogo;Itshouldbenoticedthatnotypeisspecifiedforthisquery.Aswewillsee,one of thetasksassociatedwithType-LevelProcessingistodeterminethetype(s),ifany,towhichthequeryapplies.3.InitialStepsinQueryProcessingThetask of queryprocessingconsits of severalsteps,some of whichareconcernedwithqueryoptimizationIBERT87I.Inthispaperweconsiderthepre-processingsteps,inwhichsomeinitialactivitiesareperformed,suchasqueryparsingandaccessingthetypecatalog.Alsoduringthisphase,thequeryismodifiedinlight of thetypehierarchy.3.1.ParsingThequeryisparsedbyaconventionalparser.Theparserverifiesthat...
... synchronization because of the use of correlators [3].Due to the limitations in Rake receivers, many researchers shift their research tonon-coherent UWB methods. As one of the conventional non-coherent ... spreadfor GFSK and PPM systems despite the pulse duration of a GFSK system is twice that of a PPM system. We also verify our conclusion using the Matlab code in [22] and these twosystems both obtain ... study on performance of an IR-UWB receiver based on energy detection, in IEEE International Conference on WiCOM, Dalian, China, pp.1–5, 20083. N He, C Tepedelenlioglu, Performance analysis of non-coherent...
... effect of synchronization errors on system performance is analyzed in Section 5. In Section 6, the numerical results are analyzed. InSection 7, the conclusions are stated.2 System models2.1 System ... The orthogonality of a GFSK system is achieved in thefrequency domain. Although the integration interval and synchronization error also affectperformance of a GFSK system, its orthogonality is ... pulse duration. Although the single pulse duration of a GFSK system is twicethat of a PPM system, but the values of D are almost the same. Because the multipathcomponents in these two system arrive...
... system is at mostone half of that of a PPM system. But this does notmean that the maximum possible data rate of a G FSKsystemisonehalfofthatofaPPMsystem.InUWBchannels, the multipath components ... study on performance of an IR-UWBreceiver based on energy detection. in IEEE International Conference on WiCOM, Dalian, China 1–5 (2008)3. N He, C Tepedelenlioglu, Performance analysis of non-coherent ... bandpass filter with notched band forthe rejection of 5 GHz WLAN using hexagonal multiple mode resonator. inIEEE International Conference on Communication Control and Technologies,Ramanathapuram,...
... â2005 Operating System Concepts 7thEdition, Jan 12, 2005Four Components of a Computer System Four Components of a Computer System 1.13Silberschatz, Galvin and Gagne â2005 Operating System Concepts ... Gagne â2005 Operating System Concepts 7thEdition, Jan 12, 2005Chapter 1: IntroductionChapter 1: Introduction What Operating Systems Do Computer- System Organization Computer- System Architecture ... aspects of system z Loads operatingsystemkernel and starts execution 1.4Silberschatz, Galvin and Gagne â2005 Operating System Concepts 7thEdition, Jan 12, 2005What is an Operating System? What...