The probation period work summary report

Respect leadership:

Hello!

In an instant to company has more than three months. Thanks to company for my attention, gave me such a good work environment, Thanks to the company for giving me such a good job opportunities at the leadership and my colleagues care and guidance and assistance, I successfully completed the of their own duties within the scope of the work. In the work everywhere pays attention, thinking, learn, and actively to the colleague consult, and colleague communication, understand the each department product information. Strengthen the technology learning to make up my technical deficiency. At the same time use the Technical manual to deepen understanding, to the senior staff asked, learning, to improve my technical level.

In a word, after three months of probation period, I think I can active and initiative to finish their work, and in the work can find problems, with the requirements of the overall leadership to start working with colleagues can very good cooperation. In the later work I will just as after go toward, the people: be good to others, to work: strive to perfect, and constantly improve the technology level and comprehensive quality, for

the development of our company as an own strength.

Now for me in the three months to do some of the main work make a conclusion:

1、l had complete translation all COMAC drawings into Dedienne drawings (607A010000-00 Wing Jacking Pad、607A020000-00 FWD FUSELAGE Jacking Pad 、 607A030000-00 Mid-aft FUSELAGE Jacking Pad、 607A050000-00 Tail Stanchion、610A010000-00 Mooring EQUIPMENT NLG、610A020000-00 Mooring EQUIPMENT NLG Main、610A030000-00 Mooring EQUIPMENT AFT BODY、610A040000-00 Mooring EQUIPMENT AFT BODY、624A020000-00 IDG R/I 、649A040000-00 APU CRADLE、655A020000-00 FIN FAIRING SLING、655A040000-00 EIEVATOR SLING、657A040000-00 Mooring EQUIPMENT AFT BODY) in Chinese. But for the complex products is studied to be drawing 3D .and communication and discuss the drawing problems with Xavier LABAUME . At the last all the problems have been solved. The drawings basically no problem, It can be put into production.

2、According to our existing test equipment,1 design some product test fixtures, Such as: Products C78012 - C test fixtures and laser carving machine fixed tooling.

3、According to the product,1 design some product packing container size and foam packaging; (98V2700406000、 98V32104006000、98V 32104007000、98V32104010000、98V52108800000、98V52108801000、98V52308780000、 98F57103020、5505T659-401、1324 A、 C32029-38、C32029-45 and so on).

4、 A simple modification of tow bar, for the traction rod hand pump replaced (in order to save costs, original pump is imported, the

one-piece oil pump, Now we use the domestic separated. Means: fuel tank and piston rod is separation). Then a simple modification of tow bar, namely the increase of fixed tank etc.

5、 Because we have only a testing machine in company currently, and its

range is very big, general a few load cannot control. However, our products are most is 1 ~ 10 tons pull pressure is more, a lot of tension and compression test can't in the present test machine to realize. So according to realistic situation, design a simple testing machine and a and forklift truck with fixed tooling (below), but as a result of in order to save cost and not put into production.

6、Cooperate with purchasing choose appropriate purchased part, standard

and clear drawing processing convenience purchasing with supplier offer.

7、Fit to help our processing suppliers clear drawings, according to the

product of two dimensional diagram, draw three dimensional diagram; According to the drawing work with suppliers understand product processing craft problem; Then let them more intuitive to understand the product, understanding product processing technology, and product processing process a series of problems.

8、Cooperate with production clear product drawing makes it easier for

workers to assembly, disassembly, packaging, etc.

9、Cooperate with quality control department clear drawing some

important size detection and discuss detection methods; To need to do test products with quality control department design product positioning jig and participate in product control the test process.

10、 For processing difficult, to supplier site, according to the equipment

to provide and discuss products processing and the processing technology of the engineering.

Above is my probation period in the company to do the main work, the probation period is over, I hereby apply for a raise, I hope the salary is 6000 yuan or so (excluding five risk a gold).

If the company think my present work content and quality still fail to meet the requirements of a raise, I sincerely hope you can truly be willing put forward the opinions or Suggestions, let me in the future have a direction and goals, in the ascension your ability to work at the same time will do better, to a higher goal. Also please rest assured, if the company will not be considered, I will still as before, in a positive, serious and responsible attitude to do every thing, not so slight work, this is my knowledge and training requirements I should do it.

Look forward to your reply. Thank you!

Linda

October 15、12

第二篇：Esprit BRA 6865--- Pegasus Summary Report, Applications Work Package

EspritBRA6865—Pegasus

SummaryReport,ApplicationsWorkPackage

DerekMcAuley

December2,1993

UniversityofCambridgeComputerLaboratory,PembrokeSt.,Cambridge,CB23QG,UK

Contents

1Introduction

2

ApplicationsArchitecture2.1Background

2.2ArchitecturalComponents

2.2.1UserQoSManager2.2.2TheScheduler2.2.3TheDispatcher

3ApplicationsDesign

4

ApplicationsImplementation4.1CurrentImplementation4.2PlannedImplementation

ATheWandaXServerandPandoraVideo

A.1Introduction

A.2ThePandora’sBox

A.2.1ExperimentalCon?gurationA.3TheWandaXServerA.4ThePandoraDaemon

A.4.1VideoStreamsA.4.2AudioStreamsA.5Conclusions

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1223344566xxxxxxxxxxxx1

Chapter1

Introduction

ThePegasusProject(EspritBRA6865)hassubmitteddeliverablereportsforits?rstreviewperiod(September1992toAugust1993).

Eachofthosereportsisstructuredtocoveralloftheproject’sworkpackagesfromaparticularviewpoint.Thepresentdocumentfocussesonthecommunica-tionsworkpackage,andpresentsthetopicscoveredbythedeliverablereportsastheyrelatetotheapplicationspackagealone.

Eachofthefollowingchaptersrepeatsachapterofoneofthedeliverabledocuments.

1

Chapter2

ApplicationsArchitecture

2.1Background

ThepurposeofPegasusistoinvestigateanddevelopoperatingsystemstosupportdistributedmultimediaapplications.AnalogiesbetweenNemesisandATMhavebeenmentionedalready.BothNemesisandATMattempttostructureresourcesinagenericmanner;inthecaseofATMtheresourceiscommunicationbandwidth,inthecaseofNemesistheresourcesareprocessor,memory,storagesystemand,inthefuture,processorcaches.

LikeATM,Nemesisshouldberegardedasenablingtechnology.Nemesiswillallowdistributedmultimediaapplicationstobedevelopedandtorunonopengenericplatformssharedwithotherapplications.

Nemesisisthusnotaboutdevelopingmultimediaapplicationsperse.Mul-timediaapplicationswillrequireagreatdealofotheringredients,perhapsmostnotablygreaterunderstandingofhumanfactorsandtheuserinterface.

WealsoshouldnotethatNemesis,orasimilarlyconstructedoperatingsystem,isnotanecessaryrequirementformultimediaapplicationsanymorethanisATM.Multimediaapplicationscan,andare,beconstructedalready.Theyareoftenconstructedonsystemswhicharededicatedtotheapplication;oneprovidesenoughresourcetosupporttheapplicationinastaticfashion.Thisresourceisoftenspecialised,forexampleusingDSPtechnology.Thethrustofalargepartofsuchworkistogainagreaterunderstandingofuserinterfaceissuesandwhatapplicationsareuseful,aswellastodeployapplicationsinadvanceoftheavailabilityofopenplatforms.However,someofthisworkisconcernedwithsystemissues,oftenpoisedintermsofsupportingdistributedmultimediaonexistingoperatingsystems.

Nemesisisdesignedfromablanksheetofpaper.Thuswhileourpurposeisnottodevelopapplicationsasanendproduct,someapplicationsmustbebuiltinordertodemonstrateandtestboththefunctionalityofNemesisasamanagerofresourcesandtheef?cacyoftheinterfacesprovidedbyNemesis.

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2.2ArchitecturalComponents

Thearchitecturalissueswhichimpactapplicationsarelargelydescribedelsewhereininterfacestothesupervisorandthe?lingsystem.OfparticularimportanceforapplicationswillbethenotionofaUserQoSmanager,theinterfaceprovidedbythedomainschedulerandthemannerinwhichtheprocessorisdispatchedbythescheduler.

2.2.1UserQoSManager

Itisusefultodrawadistinctionbetweenmultimediaprocesseswhichrunonserverssharedwithprocesseswhicharecompletelyindependentandmultimediaprocesseswhichrunon,forlackofabetterterm,aprivateworkstation.Notethatadistributedapplicationwillhaveprocessesonbothprivateandsharedplatforms.Onsharedservers,suchasa?leserver,serviceguaranteesmustbemadetoensurethatdifferentusersdonotinterferewitheachother.Onaprivateworkstation,theinterferencebetweenapplicationsmaybetoleratedaslongastheuserhassomecontroloverwhichapplicationsgetresourceswhenoverloadoccurs.Thereisadirectanalogyheretotheuseofawindowmanageronadisplaydevice.

Thusforprivateworkstations,thenotionofauserlevelQoSmanagermaybeappropriate.Whileitishardtodesignamanagerinadvanceofexperienceofthelowerlevelfunctionality—itwouldbethesameasdevisingawindowmanagerinadvanceofexperienceofabitmapdisplay—tworequirementsareclear.Thesehaveanalogousoperationsinwindowmanagers:

1.theabilitytodecreaseorincreasetheQoSdeliverytoaparticularapplication.ApplicationsmaybequantisedwithrespecttoQoSandtheuserQoSlevelmanagerwillhavetointeractwithapplicationstoprovidethenecessaryinformation.

2.theabilitytointeractwithuserswhenanewapplicationexperiencesre-sourcefailureinordertoallowresourcestobereclaimedfromotherappli-cations.Usersmayofcoursehavepro?leswhichtheuserQoSmanagercanusetoperformthisfunctionautomatically.

OnsharedserverstheneedsofauserQoSmanagermayseemlessobvious.However,amanagerwhichperformssimilarfunctionstomanageresourceover-loadwillberequired.ThismayhavetointeractwiththeclientenduserQoSmanagers.Forexampletheaservermaybeabletodeliverservicetoauserappli-cationprovidingthatthatuseriswillingtodegradeservicetoanotherapplicationundertheircontrol.Alternatively,aservermaybeabletodeliverurgentservicetoauserbynegotiatingresourcesfromanotheruser(oruserQoSmanager).Thiswillbeanissueinoverloaded?lesystems,butverylittlethoughthasyetbeendevotedtothissubject.

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2.2.2TheScheduler

Theschedulerrunsasaprivilegeduserleveldomain.Itisresponsiblefortranslat-ingQoSdemands,asmadebyapplications,intolowlevelschedulingdecisions.Thereasonfortheseparationoftheschedulerfromthedispatcherfunctionistoenablethetwotorunondifferenttimescales.Intheextreme,wecanen-visagestrictlyisochronousapplicationswith?xedresourcedemandswherethescheduledneedonlybecalculatedwheneveranewtaskentersthesystem–thisisdirectlyakintoacircuitswitchedapproachinnetworking.

Thedegreetowhichsuchoptimizationsarepossibleinarealsystemarebeinginvestigated.

2.2.3TheDispatcher

Asdescribedinthearchitectureofthekernelthedispatchingoftheprocessortodomainsisprovidedbydomainactivationsratherthanasresumptionsbyrestoringdomain(orthread)state.

Thismodeofoperationhasbeenselectedasitisthebasefunctionalityonwhichfourdistinctstylesofapplicationcanbeimplemented,andhasbeendrivenbytheapplicationrequirements:

1.singlethreadeddomains(traditionalUNIXstyle),

2.non-preemptivemultithreadeddomains(coroutines),

3.“real”preemptivethreads,

4.eventdrivenprogramming.

Singlethreadeddomainssimplyrestoretheirpreviouscontextonstartup.

Forthesupportofmultithreadedapplications,thereneedstobeauserlevelschedulerthatisresponsibleforasecondlevelofprocessordispatchtoindividualthreads.However,asthesestylesofprogrammingarecommonplace,thesethreadfunctionswillbeprovidedbystandardsharedlibraries(e.g.implementingthePOSIXthreadinterface).

Thediscussionofwhetherthethreadschedulingshouldbeakerneloruserleveltaskisonethatcontinuestobediscussedintheliterature.Wehavetakentheapproachofbuildingthewholeoperatingsystemfromthisstartingpointandhopetoavoidmanyoftheproblemswhicharethenencounteredinaddingscheduleractivations.

Theactivationmodelalsonaturallysupportsapplicationswhichwouldresultfromastronglyobjectbasedapproach,suchasisoftenfoundinuserinterfaceenvironments.

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Chapter3

ApplicationsDesign

Inthelatestagesoftheproject,anapplicationtoperformthetaskofatelevisiondirectorwillbedeveloped.ThedesignworkforthisapplicationhastobecarriedoutandwillbecompletedasexperiencewiththeemergingNemesissystemisgained.However,inordertogainsomeexperience,someverysimpleapplicationshavebeendevelopedontopoftheWandasystem.

The?rst"application"isasimplevideowindowdisplayingvideosourcedbytheATMcameraontheworkstationscreen.ThisisdoneonaDECStationwhoseonlyspecialhardwareisitsATMnetworkinterface.AprocessrunningontheDECStationsalsotakesframedifferencesanddisplaystheseinanothervideowindow.

Another,moreserious,applicationisthedevelopmentofanX-serveroverWandawithadaemonthatsupportsPandoraVideo[Hopper90].Againtheonly"special"hardwareistheDECStation’sATMinterface.Adescription[Barham93]ofthissystemisattached.

Whilebothoftheseapplicationsdemonstratetheef?ciencyoftheWandanetworkcode,andtheabilityofmoderndayworkstationstoshiftvideoacrosstheirbuses,theydonotexploittheQoSguaranteesthatNemesiswillmake.SuchapplicationswillofcourserequireearlyversionsoftheNemesiskernel.However,eventhesimpleapplicationsalreadydevelopedwillstressthesystemand,withminormodi?cations,shouldbeabletodemonstratebothgracefuldegradationandQoSdeliveryunderhighloading.

Theoriginaltechnicalannexcalledforacompletespeci?cationoftheTVdirectorapplicationinthe?rstyear.Duringthe?rstyear,itwasdecidedthatthespeci?cationshouldwaituntilsomeexperiencewiththeNemesisplatformwasgained.Alsosomeexperimentswithalgorithmsforlocationfromaudioandvideotrackingwillhavetobecompletedtoensurethatarealisableapplicationisspeci?ed.

5

Chapter4

ApplicationsImplementation

Applicationdevelopmentdependsuponthecompletionofotherworkpackagesandthereforeverylittleefforthasbeenspentonit.

4.1CurrentImplementation

Audioinputandoutputisbeingdeveloped,driversforDecaudioboardssup-portingtheAudioFileinterfacetorunonWandaiscurrentlybeingcompleted.(AudioFileistoaudiohardwareasXistodisplayhardware.)VideoinputviatheATMCameraisalreadyinplace.

ThePandoravideoextensionstoXhavebeenincorporatedintoaWandabasedX-serverwhichisabletoactaspartofthePandorasystem.

4.2PlannedImplementation

Milestonesforapplicationdesignandimplementationarelateintheproject,re-?ectingthedependencyontheotherworkpackages.AlsosomeexperimentshavetobeperformedontheNemesisplatformtoensurethatarealisableapplicationisspeci?ed.Themilestonesareshownintable4.1.

6

Targetdate

February1994

Locationalgorithmsrunningwithrealin-putsandevaluatedforeffectivenessandcomputationalresources;

November1994

ThedesignoftheTVdirectorwillbecomplete;

February1995

TheTVdirectorwillbeoperational.Table4.1:Applicationimplementationplan

7

AppendixA

TheWandaXServerandPandoraVideo

A.1Introduction

Traditionalmultimediaworkstationshavemadeextensiveuseofspecial-purposehardwaresuchasthePandora’sBoxforthehandlingoflivevideoandaudiostreams.Modernworkstationsarebecomingsuf?cientlypowerfultoperformmanyofthesetasksentirelyusingsoftware.AsimplefeasibilitystudyhasbeenperformedusingaDECStation5000/25workstation.

A.2ThePandora’sBox

ThePandora’sBoxisamultimediaperipheralwhichsitsbetweenahostwork-stationandanATMnetwork.Videooutputfromtheworkstationpassesthroughtheboxandlivevideostreamsaresuperimposedonthepictureinreal-time.TheboxcontainsanumberofTransputerswhicharededicatedtothistask.TheworkstationcommunicateswiththesoftwarerunningontheTransputersviaoneoftheTransputerlinks.AdaemonrunningontheworkstationunderstandsthelinkprotocolandwillcommunicaterequestsfromthehostworkstationtothePandora’sBox.

ThehostworkstationrunsanextendedXServerwhichunderstandsthecon-ceptofvideowindowsandaudioinput/output.WhentheXServerisinstructedtocreateavideowindow,itcommunicateswiththePandora’sBoxviathedaemonandcausestheBoxtosetuptheappropriatevideoandaudiostreams.Neithertheaudiostreamnorthevideostreampassthroughthehostworkstation.

A.2.1ExperimentalCon?guration

Forthepurposesofthisdemonstration,areasonablysmallpersonalworkstation,theDECStation5000/25wasused.TheworkstationwasequippedwithaATMhostinterfaceTurboChannelOptioncard(AnOlivettiResearchYesV2.2board)

8

andwasrunningtheWandamicrokernelwithitshighlyef?cientprotocolstack.Withthiscon?guration,earlierexperimentshaveshownthatitispossibletoachieveathroughputofover35Mbs1toauser-spaceprocess.Thisbandwidthshouldbemorethansuf?cientforanumberofliveaudioandvideostreams.ItwasdecidedthatthesimplestwaytosetupanemulationofaPandora’sBoxwouldbetousethesamemodi?edXServer,buttoreplacethePandoradaemonwithaprocesswhichprovidedthesamefunctionalityasthePandora’sBoxitself.ThiswouldallowthesameapplicationprogramstobeusedasforastandardPandora’sBoxsincetheyonlycommunicatewiththeXserverandthuswouldbeunabletodetectanydifference.

A.3TheWandaXServer

PortinganX11R5servertoWandarequiredverylittlework.ThemajorityoftheXServerisdeviceandoperatingsystemindependentcode.Thedevicespeci?cpartsarethosewhichcommunicatewiththekeyboard,mouseandframebuffer,andtheoperatingsystemspeci?cpartsarethosewhichhandletheTCP/IPsocketconnectionstoclients.

AnearlierprojectintheComputerLaboratoryhasproducedanimplemen-tationoftheInternetProtocol(TCP/IPandUDP/IP)overWandarunningasauser-spaceserverandasmallclientlibrary.ThelibraryprovidesaBSDsockettypeinterfacetoanapplication,andthuscouldprovidealloftheoperatingsystemfunctionswhichtheXServerrequired.

TheXserver’smodelofdevicesisheavilyin?uencedbytheUNIXmodelofdevices,inthateachdevicehasanassociated?ledescriptorwhichmaybepassedasanargumenttoaselectsystemcallinordertodeterminewhetherthedevicerequiresattention.ThedevicedriversthemselvesprovedtobeverysimpletowriteandwereinterfacedtotheXServerviaMSNLsocketswhichappearedtotheXservertobeselect-able?ledescriptors.

TheextensionoftheXserverwhichcommunicateswiththePandoradaemonalsousesasocketinterface,andsorequirednomodi?cations.ItwassimplynecessarywastoimplementaPandoradaemonreplacementwhichlistenedonthesamewell-knownportnumberandunderstoodthesameprotocol.

A.4ThePandoraDaemon

InorderforthedaemontoemulatethehardwareofthePandora’sBox,bothaudioandvideoinputandoutputdevicesandanATMnetworkinterfacewererequired.Thevideooutputdevicewassimplytheframebufferoftheworkstation,andtheDECStation5000/25hasalow-quality8-bitaudioinput/outputdevice.VideoinputwasachievedusingtheATMCameraoftheDeskAreaNetworkwhichmaybeaccessedviatheATMnetworktowhichtheworkstationisconnected.Thecurrentcameraproduces8bitmonochromeor8,16or24bitcolourvideostreams

9

withasinglelinepersegment.

ItwasrequiredthattheboxbecapableofcommunicationwithexistingPan-dora’sBoxesandsotheprotocolusedovernetworkconnectionswithotherboxeshadtobeunmodi?ed.TheprotocolusedbytheoriginalPandora’sboxescon-tainsmanyundesirablefeatures,butforthesakeofthisdemonstration,inter-operabilitywasoneofthemajorconcerns.TheprotocolconsistsofasingleATMconnectionperaudioorvideostreamwhichiscomposedofvariablesizetypedsegments.Videosegmentsarecompressedby50%usinga?xedbit-rateDPCMschemeandtypicallycontainatleasthalfaframeofvideo.

A.4.1VideoStreams

AlthoughlocalvideoconnectionsfromtheATMCameramayuseanyprotocol,itisnecessarythatoutgoingstreamsusethePandorastreamformat.Thisconver-sionmustbeperformedinsoftware.ThecolourpaletteusedbyPandora’sBoxesisparticularlystrange,andthisalsomustbe?xedinsoftware.Iftheoutgoingstreamsweretobeprocessedbytheworkstation,theneachstreamwouldcon-sumebandwidthbothenteringandleavingtheworkstation.AportcontrollerontheFairisleATMnetworkwasthususedtoperformthepaletteconversion,scalethevideostreamtothecorrectsizeandconvertittoPandorastreamformat.Thisportcontrollerwasalsousedtomulticastthestreamtoanumberofendpoints.LocalstreamssimplyusedthenormalATMCameraformatsincethesegmentsizeismuchsmallerandthustheunitoflossintheeventofanATMcellbeingdroppediscorrespondinglysmaller.ThisalsoenableslocalstreamstouseacolourvideoformatratherthanthemonochromeimposedbythePandorastreamformat.

A.4.2AudioStreams

ThedevicedriverusedtocontroltheBBAaudiodeviceontheDECStationwastheAudioFileserver.TheAudioFileserverhandlescaptureandmixingofmultipleaudiostreamsatdifferentratesandindifferentformats.TheserverbearsastrongresemblancetotheXServerandcommunicateswithitsclientsinthesamewayi.e.viaaTCP/IPstream.SincethePandoradaemonutilizedaonlysame-machineconnectionstotheAudioFileserver,theuseofareliabletransportprotocolforliveaudiodidnotprovetobetoomuchofaproblem.

A.5Conclusions

Theprototypeofthissoftwarewaseasilycapableofsimultaneouslydis-playingvideostreamsfrom15genuinePandora’sBoxeswiththelimitingfactorbeingthenumerousgatewaysbetweenthegenuinePandora’sBoxesandtheDECStation.Suf?cientCPUtimewasleftovertorunstandardXclientsatthesametime.

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AlthoughthespeedoftheworkstationCPUprovedtobenoproblem,itwasnotedthatthenumerousthreadsresponsibleforreceivingincomingvideostreamsanddisplayingthemreceivedwereunabletorunforextendedperiodsoftimewhilstotherthreadsdealtwiththeirbacklogsofincomingdata.Theresultwasthatvideowasdeliveredtothescreenatirregularintervals.Thisproblemwascausedbythepolicyofrun-to-completionforequalprioritythreadsutilizedbytheWandascheduler.

Audiodatahasmuchtighterjitterconstraintsthanvideodata,withasinglePandoraaudiosegmentcontainingapproximately2.5msofaudiodata.Itwasthusimportantforthethreadshandlingaudiostreamstorunatahigherprioritythanallofthevideothreads.

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Bibliography

Thepagesonwhicheachreferenceiscitedarelistedinparenthesesafterthereference.

[Barham93]PaulBarham.TheWandaXServerandPandoraVideo.(attached),

August1993.(5)

[Hopper90]A.Hopper.Pandora—AnExperimentalSystemforMultimediaAppli-

cations.ACMOperatingSystemsReview,24(2):19–34,April1990.

(5)

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